WIRE SAW SYSTEM

FIELD OF THE DISCLOSURE

[0001] Embodiments of the disclosure relate to an apparatus and a method for forming thin substrates from a workpiece, particularly from an ingot. Further, the present disclosure relates to a wire saw device for cutting semiconductor material, particularly for fabrication of thin crystalline silicon solar cell substrates from an ingot.

DESCRIPTION OF THE RELATED ART

[0002] Wire saw devices are used in the electronics industry to saw ingots of semiconductor material into thin slices, for example wafers. In conventional wire saw devices, the sawing region may be constituted by an assembly of parallel wire guide cylinders which are engraved with grooves. In the grooves a wire can be guided to form a wire web for cutting the ingot between the wire guide cylinders. The distance between adjacent wires of the wire web determines the thickness of the slices. Conventionally, the piece to be sawed is fixed on a movable support for urging the piece to be sawed against the wire web. For cutting, an abrasive may be used. The abrasive can, for example, be fixed on the wire or be provided in form of slurry. Accordingly, the wire acts as a carrier for the abrasive material.

[0003] For numerous applications, the sawed slices, also referred to herein as wafers, are of a very small thickness relative to the cross-section, or diameter, of the piece to be sawed. Accordingly, the sawed slices can be flexible and can come into contact with adjacent slices which can give rise to undulations, striations and irregularities on the surface of the sawed slices. These irregularities may render the slices unusable for certain applications, for example, in the solar industry or the semiconductor industry.

[0004] Particularly, wire sawing techniques have gained favor in the process of forming photovoltaic type substrates. Photovoltaic s, or solar cells, are devices which convert sunlight into direct current electrical power. Silicon substrate based solar energy technology follows two main strategies to reduce the costs of solar electricity by use of solar cells. One approach is to increase the conversion efficiency of junction devices (i.e., power output per unit area) and the other is lowering costs associated with manufacturing the solar cells. Since the effective cost reduction due to conversion efficiency is limited by fundamental thermodynamic and physical limits, the amount of possible gain depends on technological advances of the production of solar cells. Accordingly, there is a demand to reduce the manufacturing costs of solar cells.

[0005] Particularly, there exists the demand for reducing the cost of ownership for substrate fabrication equipment (e.g., high system throughput, high machine up-time, inexpensive machines, inexpensive consumable costs). Further, the manufacturing process has to be optimized with respect to the wafer quality in order to produce highly efficient solar cells. Accordingly, there is a need to cost effectively form and manufacture thin semiconductor substrates, particularly for solar cell applications.

SUMMARY OF THE DISCLOSURE

[0006] In light of the above, a wire saw system for cutting semiconductor material, a method for cutting semiconductor material into a plurality of slices, and a use of the wire saw system for cutting semiconductor material according to the independent claims are provided. Further advantages, features, aspects and details are evident from the dependent claims, the description and the drawings.

[0007] According to one aspect of the present disclosure, a wire saw system for cutting semiconductor material is provided. The wire saw system has a wire forming a wire web for cutting semiconductor material. Further, the wire saw system includes a cutting head for cutting an ingot of semiconductor material; a wire management system configured for feeding the wire towards the wire web and for receiving the wire from the wire web; an electrical control system for controlling the wire saw system; and a cooling system configured for cooling a coolant of the coolant system, wherein the coolant system is configured for cooling parts of the wire saw system.

[0008] According to another aspect of the present disclosure, a use of the wire saw system as described herein for cutting semiconductor material is provided. [0009] According to a further aspect of the present disclosure, a method for cutting semiconductor material into a plurality of slices is provided. The method for cutting semiconductor material includes: loading an ingot of semiconductor material into a wire saw system, urging the ingot against a wire web formed in a cutting zone of the wire saw system, and moving the wire web relative to the ingot. Particularly the method for cutting semiconductor material is carried out by means of the wire saw system as described herein.

[0010] The present disclosure is also directed to an apparatus for carrying out the disclosed methods and including apparatus parts for performing each described method steps. These method steps may be performed by way of hardware components, a computer programmed by appropriate software, by any combination of the two or in any other manner. Furthermore, the disclosure is also directed to methods for operating the described apparatus. It includes method steps for carrying out every function of the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments. It is to be noted, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of the scope of the present disclosure. In the drawings:

Fig. 1A shows a schematic perspective view of an arrangement of a plurality of wire saw systems according to embodiments described herein;

Fig. IB shows a schematic perspective view of a wire saw system according to embodiments described herein;

Fig. 1C shows a schematic perspective view of modules of a wire saw system according to embodiments described herein;

Fig. ID shows a schematic cross-sectional view of a wire saw system according to embodiments described herein; Fig. 2 shows a schematic explosive perspective view of a lower cutting head according to embodiments described herein;

Fig. 3 shows a schematic perspective view of a cutting zone of a wire saw system according to embodiments described herein;

Fig. 4 shows a schematic view of a wire guide having grooves according to embodiments described herein;

Fig. 5 shows a schematic view of a section of the wire guide shown in Fig. 4;

Fig. 6 shows a schematic view of a groove geometry in a wire guide according to embodiments described herein;

Fig. 7 shows a schematic view of a wire guide and clamping assembly of a wire saw system according to embodiments described herein;

Fig. 8 shows a schematic view of a wire guide and clamping assembly of a wire saw system according to embodiments described herein;

Fig. 9 shows a schematic view of an excerpt of a wire guide and clamping assembly of a wire saw system, according to embodiments described herein;

Fig. 10 shows a schematic view of an excerpt of a wire guide and clamping assembly of a wire saw system according to embodiments described herein;

Fig. 11 shows a schematic view of a connector of a wire saw system according to embodiments described herein;

Fig. 12 shows a schematic view of a connector of a wire saw system according to embodiments described herein;

Fig. 13 shows a schematic view of a wire guide and clamping assembly of a wire saw system according to embodiments described herein;

Fig. 14 shows a schematic view of a wire guide and clamping assembly of a wire saw system according to embodiments described herein; Fig. 15 shows a schematic cross-section of a wire guide according to embodiments described herein;

Fig. 16 shows a schematic view of a wire guide and clamping assembly of a wire saw system, according to embodiments described herein;

Fig. 17 shows a schematic cross-sectional view of a wire bow monitoring system in a wire saw system according to embodiments described herein;

Fig. 18 shows a schematic cross-sectional view of a wire bow monitoring system in a wire saw system, wherein the wire of the wire saw system is bowed;

Fig. 19 shows a schematic view of a sensor board of a wire bow monitoring system according to embodiments described herein;

Fig. 20 shows a schematic side view of an excerpt of a wire saw system including a wire monitoring system according to embodiments described herein;

Fig. 21 shows a schematic side view of a wire monitoring system according to embodiments described herein, wherein a first wire is in a first position;

Fig. 22 shows a schematic side view of the wire monitoring system according to Fig. 29, wherein the first wire is in a second position;

Fig. 23 shows a schematic side view of a wire monitoring system according to embodiments described herein, wherein the wire monitoring system is in a measurement position;

Fig. 24 shows a schematic side view of a wire monitoring system according to embodiments described herein, wherein the wire monitoring system is in a measurement position;

Fig. 25A shows a schematic side view of an excerpt of a wire saw system according to embodiments described herein including a wafer cleaning system according to embodiments described herein;

Fig. 25B shows a schematic perspective view of a collector box for the wafer cleaning system according to embodiments described herein; Fig. 26 shows a cross-sectional, schematic view of a frame body of a wire saw system according to embodiments described herein;

Fig. 27 shows a schematic perspective view of a frame body of a wire saw system according to embodiments described herein;

Fig. 28 shows a schematic perspective view of a frame body of a wire saw system according to embodiments described herein;

Fig. 29 shows a schematic perspective view of a frame body according to embodiments described herein;

Fig. 30 illustrates graphs comparing damping properties of cast iron frame bodies and mineral casting frame bodies according to embodiments described herein;

Fig. 31 shows a schematic perspective view of a frame body of a wire saw system according to embodiments described herein including an ingot feeding system according to embodiments described herein;

Fig. 32 shows a schematic perspective view of an ingot feeding system according to embodiments described herein;

Fig. 33 shows a schematic perspective view of a wire saw system including an ingot feeding system according to further embodiments described herein;

Fig. 34 shows a schematic perspective view of a wire management system of a wire saw system according to embodiments described herein;

Fig. 35 shows a schematic side view of a spool reception and a spool for a wire management system according to embodiments described herein;

Fig. 36 shows a schematic front view of the spool reception and the spool shown in Fig. 35 according to embodiments described herein;

Fig. 37 shows a schematic side view of a spool mounted to a spool reception of a wire management system according to embodiments described herein; Fig. 38 shows a schematic front view of the spool mounted to the spool reception shown in Fig. 37;

Fig. 39 shows a schematic side view of a spool mounted to a spool reception of a wire management system according to embodiments described herein;

Fig. 40 shows a schematic side view of a spool arrangement including a sensor arrangement according to embodiments described herein;

Fig. 41 shows a schematic side view of a spool arrangement including a sensor arrangement according to embodiments described herein;

Fig. 42 shows a schematic side view of a spool arrangement including a sensor arrangement according to embodiments described herein;

Fig. 43 shows a schematic side view of a spool mounted to a spool reception of a wire saw system according to embodiments described herein;

Fig. 44 shows a schematic side view of a mounted spool arrangement including a sensor arrangement according to embodiments described herein;

Fig. 45 shows a schematic front view of the spool arrangement including the sensor arrangement shown in Fig. 44;

Fig. 46 shows a schematic side view of an excerpt of the wire saw system according to embodiments described herein;

Fig. 47 shows a schematic side view of a tension modifier according to embodiments described herein;

Fig. 48 shows a schematic perspective view of a tension modifier according to embodiments described herein;

Fig. 49 shows a schematic side view of an exemplary guide roller of a tension modifier according to embodiments described herein;

Fig. 50 shows a schematic side view of an excerpt of a wire saw system including a tension modifier according to embodiments described herein; Fig. 51 shows a schematic side view of an excerpt of a wire saw system including a tension modifier according to embodiments described herein;

Fig. 52 shows a schematic cross-sectional side view of an excerpt of an exemplary wire inspection system according to embodiments described herein; and

Fig. 53 shows a block diagram illustrating a method for cutting semiconductor material according to embodiments as described herein.

DETAILED DESCRIPTION OF EMBODIMENTS

[0012] Reference will now be made in detail to the various embodiments of the disclosure, one or more examples of which are illustrated in the figures. Within the following description of the drawings, the same reference numbers refer to same components. In the following, only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the disclosure and is not meant as a limitation of the disclosure. Further, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the description includes such modifications and variations.

[0013] In the present disclosure, "wire saw", "wire saw device" and "wire saw system" may be used interchangeably. Herein, a "wire saw" may be understood as a device for cutting a workpiece of semiconductor material, particularly into a plurality of slices, for example wafers. Further, in the present disclosure, a workpiece may include one or more separate pieces, for example a plurality of semiconductor pieces or ingots.

[0014] Fig. 1A shows a schematic perspective view of an arrangement of a plurality of wire sawing systems according to embodiments described herein. In Fig. 1A an arrangement of six wire sawing systems is shown. As exemplarily shown in Fig. 1A, the arrangement of the plurality of wire sawing systems may include at least two rows of wire sawing systems. A wire saw system 1000 according to embodiments described herein includes: a cutting head 1100, a wire management system 1200, an electrical control system 1300, a coolant system 1400 and a cooling system 1500. Embodiments of the wire saw system as described herein may be adapted to perform the cutting of semiconductor material by use of a single wire. [0015] According to embodiments described herein, the cutting head 1100 is configured for cutting a workpiece by means of a wire web. The wire management system 1200 may be configured for supplying a wire forming the wire web in a cutting zone of the cutting head. Further, the wire management system 1200 may be configured for taking up the wire used in the cutting zone of the cutting head. The electrical control system 1300 may be configured for controlling various components, for example actuators and/or sensors employed in the wire saw system as described herein. The electrical control system 1300 may also be connected to a computer network to be controlled directly or remotely by an individual or an automated system such as a computer.

[0016] According to embodiments described herein, the electrical control system 1300 may include computer programs, software, computer software products and the interrelated controllers, which can have a CPU, a memory, a user interface, and input and output means being in communication with the corresponding components of the wire saw system as described herein. These components can be one or more of the components: actuators, motors or breaks for moving parts of the cutting head and/or of the wire managements system; or valves and pumps of the cooling system and/ or coolant system.

[0017] According to embodiments described herein, the cooling system 1500 may be configured for cooling the coolant of the coolant system 1400. The coolant system may be configured for cooling various parts of the wire saw system which may heat up during operation of the wires saw system. Particularly, the coolant system 1400 may be configured for providing a cooling of moving parts of the wire saw system.

[0018] According to embodiments described herein, the wire saw system can be used to form different types of substrates, or wafers, such as solar cell substrates, semiconductor substrates, or other useful substrates from a larger piece, such as an ingot, boule or block.

[0019] In the present disclosure "ingot" may be understood broadly to signify at least one larger piece, or un-cut element, that is to be sawed in the wire saw system. An "ingot" may include one or more separate semiconductor pieces, for example a plurality of semiconductor pieces. Herein, "semiconductor" refers to semiconductor materials such as those used in the photovoltaic industry. [0020] According to embodiments of the wire saw system as described herein, a wire including high strength steel may be used for sawing ingots of hard material. More particularly, the wire employed by the wire saw system as described herein may be suitable for cutting silicon, ceramic, compounds of the elements of groups III-V and II- VI, GGG (gadolinium gallium garnet), sapphire, etc. Further, the wire employed by the wire saw system as described herein may be suitable for cutting materials as described herein into slices of about 300 microns (μιη) or less, or for example of about 180 microns (μιη) or less, or of about 80 microns (μιη) or less in thickness.

[0021] The wire speed, that is the speed of the wire moving through the wire saw can be, for example, 10 m/s or even higher. The wire speed can be in a range of 0.1 to 25 m/s. Higher wire speeds, such as 26 m/s or 40 m/s can also be applied. According to embodiments, the movement of the wire may only be unidirectional, i.e., always in the forward direction. According to other embodiments, the movement may include a movement in the backward direction, in particular, the movement can be a back-and-forth movement of the wire in which the movement direction of the wire is amended repeatedly.

[0022] In some embodiments of the present disclosure the wire saw is controlled such that the wire moves forwards and backwards in an alternating manner. As discussed, the wire length moving forwards can be either larger, smaller or equal than the wire length moving backwards, such as by between 100% and 95%. Particularly, the movement direction (i.e., forwards and backwards) is operated for a time interval of between 10 s and 5 min, more particularly between 10 s and 1 min. As discussed, it is possible that the time interval for the forward movement is larger than the time interval for the backward movement, such as by at least 0.5% or 1%.

[0023] According to embodiments, which can be combined with other embodiments described herein, the wires saw system can be adapted for thin wires having a diameter below about 150 microns (μιη), such as diameters between about 100 microns (μιη) and about 150 microns (μιη), particularly between about 50 microns (μιη) and about 150 microns (μιη), more particularly between 50 microns (μιη) and 100 microns (μιη), for example 120 microns (μιη). In other cases, embodiments may also have a wire diameter as low as, for example, 100 microns (μιη), 80 microns (μιη), 70 microns (μιη) or 60 microns (μιη). [0024] In the present disclosure, the term "wire diameter" is to be understood as the apparent external diameter of the wire. For example, in case a wire is used in which an abrasive is provided on the wire as a coating or bonding, e.g. as with diamond wire, the "wire diameter" is to be understood as the diameter of the wire core plus the thickness of the coating (e.g. nickel coating) or the resin bonded over the diameter. For example, diamond particles can be provided on a metal wire with a coating (e.g. nickel coating) or the resin bond, wherein the diamond particles are imbedded in the coating (e.g. nickel coating) or the resin bond of the wire. Hence, the "wire diameter" of a diamond wire may vary locally around the circumference depending on the density and shape of diamond grits imbedded in the coating (e.g. nickel coating) or the resin bond.

[0025] According to embodiments, the wire employed for cutting may be diamond wire. By using diamond wire, the throughput may be increased by a factor of 2 or even more in comparison to conventional steel wire.

[0026] According to embodiments which can be combined with other embodiments described herein, an abrasive agent can be used, which can be a commercial product, such as diamond, silicon carbide, alumina, or other useful material that is used to improve the ingot sawing process. The abrasive agent may be fixed to the wires, or be in a free form that is in suspension in a liquid (e.g., PEG), such as a slurry, which serves as a transport for the abrasive particles.

[0027] Fig. IB shows a schematic perspective front view of a wire saw system 1000 according to embodiments described herein. According to embodiments of the cutting head of the wire saw system as described herein, the cutting head 1100 may include a lower cutting head 1100 A and an upper cutting head 1100B. The lower cutting head 1100 A may include the cutting zone in which the sawing of workpieces, particularly of ingots, may be performed. The upper cutting head 1100B may include an ingot feeding system which is configured for controlling the position of a piece to be sawed, e.g. an ingot, during cutting. In the cutting zone of the lower cutting head, a wire web is formed by a wire which is guided by a first wire guide 112 and a second wire guide 114. During cutting, the first wire guide 112 and the second wire guide 114 are rotated for moving the wire web relative to a workpiece to be sawed. [0028] In the present disclosure, the terms "sawing" and "cutting" may be used interchangeably. Further, in the present disclosure the process of sawing may correspond to the process of cutting. Accordingly, the verb "to saw" with all adequate grammatical conjugations may be used as having the same meaning as the verb "to cut" with all adequate grammatical conjugations.

[0029] In the present disclosure, the term "wire web" may be understood as a web formed by the wire between two wire guide cylinders. Particularly, a "wire web" includes a wire being arranged in parallel, forming wire rows. Herein, "wire guide cylinder", "guide cylinder", "cylindrical wire guide" and "wire guide" may be used interchangeably.

[0030] With exemplary reference to Fig. IB, according to embodiments described herein, the wire management system 1200 may be configured for feeding the wire 11 towards the wire web. According to some embodiments, which can be combined with other embodiments described herein, the wire is provided on a supply spool 134. According to embodiments, the supply spool 134 may be provided with a wire reservoir. The supply spool 134, if complete, can hold for example about 50 kilometers or even several hundred kilometers of wire.

[0031] According to embodiments the wire is guided over a plurality of pulleys 313 into the cutting zone of the lower cutting head. After cutting, the wire is guided via several pulleys towards the wire management system 1200 and is therein provided over pulleys to the take-up spool 138.

[0032] As exemplarily shown in Figs. 1A and IB, the wire saw system can include a control panel 1110 for controlling the operation of the wire saw system. Further, the control panel 1110 may include devices for interaction with an individual in order to receive commands and to report the status of the sawing process. For example, the control panel may include a touch screen as a man-machine interface. According to embodiments, the control panel may be connected to the cutting head 1100 via an arm 1112. The arm 1112 may be movable for and configured for ergonomic adjustment according to the operators Physiology.

[0033] As exemplarily shown in Figure 1C, the wire saw system as described herein may include modules. For example, a first module can be the cutting head 1100; a second module can be the wire management system 1200; a third module can be the electrical control system 1300; a fourth module can be the coolant system 1400; and a fifth module can be the cooling system 1500. Further, according to embodiments described herein an ingot loader 1600 for loading an ingot to the wire saw system may be provided, as exemplarily shown in Fig. 1C. Particularly, the ingot loader is configured for loading an ingot to the wire saw system as described herein. For example, the ingot loader may include an ingot carrier to which an ingot to be loaded into the cutting head of the wire saw system can be mounted. The ingot loader may particularly be configured for precise coupling of the ingot to the ingot feed system as described herein.

[0034] Fig. ID shows a schematic cross-sectional view of a wire saw system according to embodiments described herein. According to embodiments, the wire saw system includes a housing 1111. The housing can be separated into different compartments. For example, the housing can include a first compartment 1111 A in which the wire web 111 is formed. According to embodiments described herein the first compartment 1111 A, may also be referred to as wire web compartment. Further, the housing 1111 may include a second compartment H UB which may house the wire management system 1200. Additionally, the housing can include a third compartment 1111C which my house the coolant system 1400 and the cooling system 1500.

[0035] As exemplarily shown in Fig. ID, the wire can be guided from the wire managements system over a plurality of pulleys 313 into the wire web compartment to form a wire web 111. As can be seen from the wire web 111 formed by the wire 11 in the wire web compartment, the wire saw system according to embodiments described herein can be used to cut ingots into wafers. The wire that is used for sawing can be provided with an abrasive material. As one option, the abrasive material can be provided as slurry. This may be done shortly before the wire touches the material to be cut. Accordingly, the abrasive is carried to the cutting position by the wire for cutting the material. As another option, the abrasive can be provided on the wire with a coating. For example, diamond particles can be provided on a metal wire, e.g. with a coating, wherein the diamond particles are imbedded in the coating of the wire. Accordingly, the abrasive is firmly connected with the wire.

[0036] As exemplarily shown in Fig. ID, according to embodiments of the wire saw system described herein, the third compartment 1111C may include the coolant system 1400 including a first tank 118 and a second tank 119 as well as a first pump 121 and a second pump 125. According to some embodiments of the wire saw system as described herein, the first tank 118 can be used for unused cooling fluid, e.g. in the case where the wire saw device is operated with diamond wire. Alternatively, the first tank 118 may be used for unused (fresh) slurry, in the case where the wire saw system 1000 is operated with a wire and additional abrasive. The first pump 121 may pump the cooling fluid (or slurry, respectively) towards the desired position in the cutting zone. This is indicated in Fig. ID by a first conduit 522. The used cooling fluid (or slurry) may flow back through a second conduit 526 and is pumped by the second pump 125 into the second tank 119.

[0037] According to some embodiments as described herein, for example in which cooling fluid or slurry is used, a portion of the used consumable fluid can be re-used if it is reinserted into the first tank 118. Thus, according to some embodiments only a portion of the consumable fluid, all of the consumable fluid or none of the consumable fluid may be reused and, thus, be reinserted in the first tank 118. As one example, an additional valve might be provided in conduit 526 for selectively choosing the tank into which the used fluid is pumped. According to another example, a fluid connection between the second tank 119 and the first tank 118 can be provided in order to reinsert a portion of the used fluid in the first tank 118. According to different embodiments, as already described above, the consumable fluid can be cooling fluid or slurry. In case that slurry is used, the slurry also takes over the function of cooling the position at which the wire cuts the material. Slurry as understood herein refers to a liquid carrier with suspended abrasion particles (e.g., particles of silicon carbide).

[0038] As indicated by the dotted lines in Fig. ID the electrical control system 1300 may serve to control the operation of the different components. For example, operation of the first pump 121 and the second pump 125, rotation of the supply spool 134 and take-up spool 138 can be controlled. Further, additionally or optionally, the filling level of the first tank 118 and second tank 119 can be measured and respective signals can be fed to the control unit. According to further embodiments, other control signals and monitoring signals can be fed to and from the electrical control system 1300. For example, signals from the motors driving the spools, pressure signals for feeding the consumable fluids like slurry or cooling fluid, or a wire break detection signal can be fed to and from the electrical control system. In Fig. 2A, an external electrical control system is shown, i.e. an electrical control system which is located outside the housing 1111 of the wire saw system. It is apparent to a person skilled in the art that an electrical control system can also be provided at a different location in the housing of the wire saw system and corresponding control signals from and to the control system can be provided accordingly.

[0039] In the following, various aspects of the lower cutting head 1100A according to embodiments of the wire saw system as described herein are described.

[0040] Fig. 2 shows a schematic explosive perspective view of the lower cutting head 1100A according to embodiments described herein. The lower cutting head can include a first wire guide assembly and a second wire guide assembly. According to embodiments, the first wire guide assembly may include the first wire guide 112, a first shaft side connector 502A that is adapted to mate with a first wire guide side connector 503A on the first wire guide 112, and a second shaft side connector 505A that is adapted to mate with a second wire guide side connector 504A on the first wire guide 112. The second wire guide assembly may include the second wire guide 114, a third side connector 502B that is adapted to mate with a third wire guide side connector 503B on the second wire guide 114, and a fourth shaft side connector 505B that is adapted to mate with a fourth wire guide side connector 504B on the second wire guide 114. Further, the lower cutting head 1100A can include a frame body 1122 with at least four openings configured for receiving the first wire guide 112 and the second wire guide 114, respectively.

[0041] With exemplary reference to Fig. 2, the lower cutting head 1100 A may include a wire bow monitoring system 160 having a sensor arrangement. The sensor arrangement can be adapted to be positioned adjacent to a wire of the wire saw system to detect a bow of the wire. Further, the lower cutting head may include a cleaning nozzle arrangement 510 for cleaning the first wire guide and the second wire guide. Additionally, the lower cutting head may include a process nozzle arrangement 530 for applying slurry to the wire web. Further, the lower cutting head may include a wire supply pulley 101 for supplying the wire 11 form the wire management system to the wire web and a wire receiving pulley 102 for receiving the wire from the wire web and guiding the wire to the wire management system.

[0042] Fig. 3 shows a schematic view of an excerpt of the lower cutting head of the wire saw system according to embodiments described herein. As exemplarily shown in Fig. 3, the wire supply pulley 101 for supplying the wire 11 form the wire management system to the wire web maybe arranged under a different deflection angel than the wire receiving pulley 102 for receiving the wire from the wire web. According to embodiments which can be combined with other embodiments described herein, the deflection angle of the wire supply pulley 101 and/or the deflection angle of the wire receiving pulley may be adjustable. Further the distance D between the wire supply pulley 101 and the wire receiving pulley 102 may be adjustable. Accordingly, the wire web may be regularly formed between the first wire guide and the second wire guide.

[0043] As exemplarily shown in Fig. 3, the first wire guide 112 and the second wire guide 114 may be connected to a motor or drive, for example to a first motor 122 and a second motor 124. According to embodiments, the first motor 122 and the second motor 124 may be adapted for performing a back-and-forth movement of the wire 11. Further, according to embodiments described herein, as exemplarily shown in Fig. 3, a first bearing box 152 for supporting the first wire guide and a second bearing box 154 for supporting the second wire guide may be provided.

[0044] In the following, embodiments of a wire guide for a wire saw system as described herein are described. The following description of exemplary embodiments of the wire guide may apply to the first wire guide 112 and the second wire guide 114 of the wire saw system as described herein, for example as described above in connection Figs. ID and 2.

[0045] Fig. 4 shows a schematic view of a wire guide 200 according to embodiments described herein, particularly of the first wire guide 112 and the second wire guide 114 of the wire saw system as described herein. Accordingly, exemplary embodiments described herein for a wire guide 200 may correspond to possible embodiments of the first wire guide 112 and the second wire guide 114 as described herein. The wire guide 200 may have a longitudinal axis 10, about which the wire guide 200 may be rotated. The wire guide 200, as described herein, may include a cylindrical unit 211, on the circumferential surface of which a plurality of grooves 223 are formed. As an example, the first groove 221 of the plurality of grooves and the last groove 222 are indicated in Fig. 4.

[0046] On the right side of Fig. 4, a frontal view of the wire guide according to embodiments described herein is shown, indicating a radial direction 292 and a circumferential direction 291 of the wire guide or the cylindrical unit. The grooves are formed on the circumferential surface of the wire guide and have an extension in the radial direction 292 into the wire guide. Further, the wire guide 200 may provide a width 290 in the cross direction of the wire guide which is substantially perpendicular to the radial direction 292. In the exemplary embodiment shown in Fig. 4, the plurality of grooves 223 can be formed over the complete width of the wire guide 200.

[0047] According to embodiments of the wire guide as described herein, each groove of the plurality of grooves 223 is defined by at least one actual dimension. Fig. 5 shows an enlarged section 280 of the cylindrical unit 211 of the wire guide 200 shown in Fig. 4. In the enlarged section 280 of Fig. 5, the grooves 223, which are exemplarily shown as V-shaped grooves, can be seen in more detail. Further, the enlarged section 280 of Fig. 5 shows that each groove of the plurality of grooves 223 has an extension in several directions (the extension in one direction may also be referred to as a dimension of the groove), such as a depth in the cylindrical unit, a width and a pitch, which will be explained in detail below with respect to Fig. 6.

[0048] According to embodiments of the wire guide as described herein, the grooves of the wire guide have a nominal dimension, which may be a predetermined value of a dimension, or a desirable or ideal value of a dimension. In some embodiments, a nominal dimension value is equal for every groove in the cylindrical unit so that exactly one nominal dimension value exists for one dimension of the grooves. According to some embodiments, each groove may have a nominal dimension, which may, for instance, depend on the position of the groove on the wire guide. The actual dimension of the groove is the dimension the groove has after the formation in the cylindrical unit. Due to process and material variations, the actual dimension may differ from the nominal dimension. In embodiments described herein, the actual dimension of each of the grooves in the cylindrical unit has a deviation of for example less than about 5% from the nominal dimension, particularly less than about 3% from the nominal dimension, and even more particularly less than about 2% of the nominal dimension for the groove.

[0049] When forming the grooves, it is desirable to form the grooves very accurately as the grooving process and the resulting groove geometry has an impact on different factors, such as the thickness of the wafers to be cut by the wire saw device, or wire vibrations during the cutting process, which are caused when the grooving pitch is not formed very regularly along the width of the wire guide.

[0050] The wire position and holding in the groove, the deepness, and the shape of the groove makes sure that the wire is maintained at a defined position while the wire guide rotates. If the grooving profile is not regular, the wire could vibrate and/or jump out of one groove during the cut, thus generating wire jumps. These vibrations and/or wire jumps damage the wafers and are a source of wire breakage. The resulting interruption of the cutting process is expensive and time-consuming.

[0051] Thus, it is desirable to provide regular and reliably continuous dimensions of the grooves on the wire guide. According to some embodiments, the deviation of an actual dimension of each of the grooves from the nominal dimension being less than about 5 microns (μιη) may be sufficient to obtain a satisfactory wire saw processing quality as well as a sufficient and reproducible slice quality or wafer quality, in particular regarding actual trends in wire sawing.

[0052] According to embodiments of the wire guide as described herein, the reliably continuous shape formation with only a minor deviation of the groove geometry from the nominal dimensions is achieved by forming the grooves by laser ablation. By using laser ablation according to embodiments described herein, actual trends in the wafer production, for example using thinner wires for production of thinner wafer slices, can be handled. While the mechanical grooving might supply a possibly sufficient groove quality for wire saws of the state of the art, it is difficult to achieve the quality adequate for actual trends in wire sawing by using mechanical grooving.

[0053] Laser ablation significantly improves the grooving process of the wire guides due to several reasons. Due to the fact that laser ablation is a non-contact grooving process, the impact of the creep of the material is for instance reduced or even wholly avoided.

[0054] By using a laser ablation technique for forming the groves in a wire guide according to embodiments described herein, geometrical dimensions, such as the deepness and the shape of the grooves may be better controlled compared to known techniques. Also, problems introduced by the wear of the diamond tools used for the grooving are avoided when using the methods and systems for forming the grooves in the wire guide according to embodiments described herein. Further, the repeatability and the quality of the grooves are strongly enhanced in wire guides according to embodiments described herein.

[0055] A further aspect of forming wire guide grooves by laser ablation is that almost arbitrary shapes of grooves may be formed. In particular, the laser ablation technique allows for a great variability of groove shapes, which is not possible - or only with an uneconomical high effort -when using mechanical grooving.

[0056] In Fig. 6, some possible dimensions of a groove in a wire guide according to embodiments described herein are shown. As an example of a groove shape, the grooves 420 in Fig. 6 are substantially formed in a V-like shape, but the dimensions referred to herein are not limited to a V-like shape of the groove in the wire guide. In Fig.6, the grooves 420 can be seen being formed in the outer circumferential surface 415 of the cylindrical unit 211 of the wire guide, as explained above. According to some embodiments, the grooves 420 are formed in a coating being arranged at the circumferential surface of a body of the cylindrical unit 211.

[0057] The term "substantially" as used herein may mean that there may be a certain deviation from the characteristic denoted with "substantially." For instance, the term "substantially V-like shaped" refers to a shape which may have certain deviations from the exact V-shape, such as a deviation of about 1% to 10% of the extension of the V-shape in one direction. Further characteristics may also be denoted with "substantially" and it should be understood that a similar interpretation as exemplarily provided above with respect to the V- shape may be applied, such as an interpretation allowing a 1% to 10% deviation from the described characteristic.

[0058] With exemplary reference to Fig. 6, the grooves of the wire guide have several geometrical dimensions. For instance, a groove 420 in a wire guide according to embodiments described herein, may have a depth 430 measured from the outer circumferential surface 415 of the cylindrical unit 211. Further, the groove in the wire guide may have a width 440 in a cross direction of the cylindrical unit at the outer circumferential surface 415 of the cylindrical unit 211. Additionally, the groove in the wire guide can have a pitch 450 being defined as the distance between the center of one groove to the center of the adjacent groove. Further, the groove in the wire guide may have a distance 470 between the end of one groove and the beginning of the adjacent groove at the outer circumferential surface 415 of the cylindrical unit 211, an opening angle 460, and the like.

[0059] According to some embodiments, which may be combined with further embodiments described herein, the depth 430 of a groove ranging from the outer circumferential surface 415 of the cylindrical unit 211 to the bottom of the groove 420 may be particularly between about 100 microns (μιη) and about 400 microns (μιη), more particularly between about 120 microns (μιη) to about 200 microns (μιη), and even more particularly between about 150 microns (μιη) and about 200 microns (μιη), such as 170 microns (μιη). The width 440 of a groove may be particularly between about 120 microns (μιη) and about 1000 microns (μιη), more particularly between about 150 microns (μιη) and about 230 microns (μιη), and even more particularly about 220 microns (μιη). According to some embodiments, the pitch 450 may particularly be between about 100 microns (μιη) and about 5000 microns (μιη), more particularly between about 150 microns (μιη) to about 350 microns (μιη), and even more particularly between about 150 microns (μιη) and about 200 microns (μιη). In one example, the pitch may be about 355 microns (μιη). It should be noted that the center of a groove may be defined by the middle point between the beginning of the groove at the surface of the cylindrical unit and the end of the groove at the surface of the cylindrical unit.

[0060] According to some embodiments described herein, the distance 470 between the beginning of one groove, at the surface of the cylindrical unit, and the beginning of an adjacent groove, at the surface of the cylindrical unit, may particularly be between about 10 microns (μιη) and about 5000 microns (μιη). The opening angle 460 may particularly be between about 30° to 100°.

[0061] It should be understood that the values given are only examples for the respective dimension. For instance, a dimension value, such as the value for the width may depend on the groove shape and may deviate from the above discussed example values dependent on the shape.

[0062] In Fig. 6, the wire 11 is exemplarily shown in one of the grooves 420. The wire 11 may have an outer wire diameter 485 of about 50 microns (μιη) to 250 microns (μιη), particularly about 70 (μιη) microns to 150 microns (μιη), and more particularly between about 80 microns (μιη) to about 140 microns (μιη).

[0063] According to some embodiments, the cylindrical unit of the wire guide as described herein, may have a width in a cross direction of about 500 mm to about 1000 mm, particularly between about 600 mm to about 800 mm, and more particularly of about 700 mm. The width of the cylindrical unit in the cross direction is exemplarily shown in Fig. 4 as width 290. The number of grooves formed on the surface of the cylindrical unit of the wire guide may exemplarily be between about 150 and about 6000 grooves, particularly between 1200 and about 4000 grooves, more particularly between about 1700 and about 3500 grooves on one wire guide.

[0064] According to embodiments described herein, the above described dimensions like the depth 430, the width 440, the pitch 450, the opening angle 460, and the distance 470 may deviate less than about 5 microns (μιη), or less than 5% from the nominal dimension of the wire guide. The accuracy of a deviation of less than about 5% of each of the grooves over the whole width of the cylindrical unit (such as the width 290 shown in Fig. 4) may be achieved by using a laser ablation technique for forming the grooves as described in embodiments herein.

[0065] It should also be noted that a nominal value for a dimension of the groove, as mentioned above, may change over the width of the cylindrical unit. For instance, referring back to Fig. 4, the first groove 221 at the left side of the cylindrical unit may have a different dimension than the last groove 222 at the right side of the cylindrical unit due to different nominal values for these grooves. In one example, the nominal value for the pitch may differ when going from the left side of the wire guide to the right side of the wire guide. For example, the pitch of the first groove 221 may differ from the last groove 222 by 5% or less.

[0066] With the deviation of a dimension of less than about 5% from the nominal dimension, the following dimension deviations may occur in a wire guide according to embodiments described herein. For instance, the deviation of the depth 430 from a nominal depth may be less than about 12 microns (μιη), particularly less than about 8 microns (μιη), and more particularly less than about 5 microns (μιη). The deviation of the width 440 from a nominal width may be less than about 12 microns (μιη), particularly less than about 10 microns (μιη), or more particularly less than about 5 microns (μιη). The deviation of the pitch 450 from a nominal pitch may be less than 8 microns (μιη), particularly less than about 6 microns (μιη), and more particularly less than about4.5 microns (μιη).

[0067] The deviation of the opening angle 460 from a nominal opening angle may be less than 5°, particularly less than about 4°, and more particularly less than about 3°. The deviation of the distance 470 from a nominal distance may be less than about 3 microns (μιη), particularly less than about 2 microns (μιη), and more particularly less than about 1 micron (μη ). [0068] In some embodiments, especially when the deviation of the actual dimension of the groove from the nominal dimension of the groove is less than 3%, the deviation of the depth 430 from the nominal depth may be less than about 7 microns (μιη), particularly less than about 5 microns (μιη), and more particularly less than about 3 microns (μιη). The deviation of the width 440 from the nominal width may be less than about 7 microns (μιη), particularly less than about 5 microns (μιη), or more particularly less than about 4 microns (μιη). The deviation of the pitch 450 from the nominal pitch may be less than about 12 microns (μιη), particularly less than about 6 microns (μιη), and more particularly less than 3 microns (μιη).

[0069] The deviation of the opening angle 460 from the nominal opening angle may be less than about 3°, particularly less than about 2°, and more particularly less than about 1°. The deviation of the distance 470 from the nominal distance may be less than about 2 microns (μιη), particularly less than about 1 micron (μιη) and less than about 0.6 micron (μιη).

[0070] In some embodiments, about 1% of the grooves may have a deviation of the actual dimension from the nominal dimension which exceeds the above referenced values, e.g. about 1% of the grooves may have a deviation of the actual dimension from the nominal dimension being larger than 5%.

[0071] The cylindrical body of the wire guide according to embodiments described herein may be made of steel or carbon fiber reinforced polymer (CFRP) material and may be coated on the cylindrical surface with a soft material, such as a polymer material, e.g. a polyurethane compound. According to some embodiments, the grooves having the above described reliability in the geometrical dimensions from the first to the last groove may be formed in the soft material coating of the cylindrical unit by laser ablation.

[0072] In using a laser ablation technique for forming grooves in a wire guide, finer grooves may be formed on the surface of the cylindrical unit. The market trend is to reduce wafer thickness and to reduce kerf by using finer wires. Thus, the mechanical grooving will, sooner or later, be faced with dimension limitations, which are not present, when using laser ablation technology. When using a laser ablation technique according to embodiments described herein, a smaller pitch for a smaller wafer thickness can be achieved. [0073] The laser ablation technology presents further benefits, like the possibility to form and use new shapes for the grooves, thus allowing a better positioning and holding of the wire during the sawing process. In known wire guides, V-shapes are used for the grooves because of the limitations of the diamond tools. With the method and the system according to embodiments described herein, shapes with rounded or flat bottoms or with different kinds of slopes can be generated.

[0074] According to embodiments described herein, a wire guide 200 for a wire saw system 1000 as described herein is provided. The wire guide includes a nominal dimension for grooves in the wire guide. The wire guide includes: a cylindrical unit 211 comprising an outer circumferential surface 415 and a plurality of grooves being formed in the outer circumferential surface 415 of the cylindrical unit 211, particularly by laser ablation, wherein each groove is defined by at least one actual dimension. The actual dimension of each of the grooves has a deviation of less than about 5% from the nominal dimension.

[0075] According to embodiments of the wire guide, which can be combined with other embodiments described herein, the deviation of the actual dimension is less than about 3% from the nominal dimension. Additionally of alternatively, the deviation of the actual dimension is less than about 5 microns (μιη) from the nominal dimension.

[0076] According to embodiments of the wire guide, which can be combined with other embodiments described herein, a first dimension of the groove is a width 440 of the groove in a cross direction of the cylindrical unit 211. The width 440 can be from about 120 microns (μιη) to about 400 microns (μιη). Additionally or alternatively, a second dimension of the groove is a depth 430 of the groove in a radial direction of the cylindrical unit 211. The depth 430 can be from about 100 microns (μιη) to about 400 microns (μιη). Additionally or alternatively, a third dimension of the groove is a pitch 450 from the center of one groove to the center of an adjacent groove. The pitch can be from about 100 microns (μιη) to about 5000 microns (μιη).

[0077] According to embodiments of the wire guide, which can be combined with other embodiments described herein, the plurality of grooves includes from about 150 to about 6000 grooves. The width 290 of the cylindrical unit 211 in cross -direction can be from about 500 mm to about 1000 mm. [0078] According to embodiments of the wire guide, which can be combined with other embodiments described herein, the cylindrical unit 211 includes a cylindrical main body being coated with a polymer, and the grooves are formed in the polymer coating.

[0079] In the following, embodiments of a bearing box and a clamping assembly for a wire saw system as described herein are described.

[0080] Fig. 7 illustrates a side view of the wire guide 200 as described herein. According to embodiments described herein, the wire guide is configured to be rapidly replaced, for example during maintenance activities. As described above, the wire guide 200 has a plurality of grooves 223 which may define the pitch between adjacent wires of a layer of wires, for example the distance from the center of one wire to its nearest (two) neighbor(s) in a wire web. During cutting, for example, the wire guide 200 rotates about the axis 10, and the wire movement is partly on the rotating surface of the wire guide 200, i.e. along the plurality of grooves 223 of the wire guide 200

[0081] According to embodiments of the wire guide as described herein, the wire guide is adapted for cutting wafers that are from about 0.02 mm through 5 mm thick. The wire and/or wire guide can become worn or damaged through use, so the wire and/or wire guide is occasionally and/or regularly replaced and/or subjected to maintenance, which temporarily can halt wafer cutting. It is desirable to minimize the time of replacement of the wire and/or wire guide, to maximize throughput.

[0082] With exemplary reference to Fig. 7, a wire guide assembly according to embodiments as described herein, may include a wire guide 200 and a clamping assembly for connecting the wire guide to a shaft of the wire saw system as described herein. The wire guide assembly can include a first shaft side connector 502 that is adapted to mate with a first wire guide side connector 503 on the wire guide 200, and a second shaft side connector 505 that is adapted to mate with a second wire guide side connector 504 on the wire guide 200. The first wire guide side connector 503 and the second wire guide side connector 504 may be integral to the wire guide, formed on the wire guide and/or attached to the wire guide. The first shaft side connector 502 and the second shaft side connector 505 may be formed on and/or attachable to a respective shaft, bearing box shaft, bearing box, axle, rotating member, or the like; herein referred to as shaft, which is rotatable about an axis 10 of rotation. One or both of the first shaft side connector 502 and the second shaft side connector 505 may be attached to a respective shaft, the same shaft, and/or shaft assembly. The axis 10 of rotation coincides with a symmetry axis of the wire guide 200 and connectors, and/or the clamping assembly which optionally includes the wire guide and/or shaft.

[0083] Fig. 7 illustrates a disconnected configuration of a wire guide assembly, e.g. the wire guide 200 is disengaged and the complementary connector pairs (for example the first shaft side connector 502 and the first wire guide connector 503 as well as the second shaft side connector 505 and the second wire guide side connector 504) do not abut. A disconnected and/or partially disconnected configuration in which only one of the complementary connector pairs do not abut is also contemplated.

[0084] In the present disclosure, "connectors" can be understood as components of a clamping assembly for a wire saw system for connecting a wire guide, particularly a cylindrical wire guide, to a wire saw, or vice versa, i.e. for connecting the wire saw, particularly a shaft of the wire saw to a wire guide.

[0085] According to embodiments of the wire guide assembly as described herein, the first shaft side connector 502 and the second shaft side connector 505 may be referred to as "outer connectors" or "connectors". Further, the first wire guide side connector 503 and the second wire guide side connector 504 may be referred to as "inner connectors" or "connectors".

[0086] In the present disclosure, "outer" and "inner" may be used to convey axial directions, and in this context, "inner" may refer to a direction toward the center of a component and "outer" may refer to away from the center of the component.

[0087] In an exemplary context, "inner" and "outer" are used when referring to different connectors, such as complementary "inner" and "outer" connectors (e.g. wire guide side and shaft side connectors), which are inner and outer with respect to the center of the wire guide.

[0088] In the embodiment shown in Fig. 8, the shaft side connectors are female and the wire guide side connectors are male. Other arrangements are also contemplated (e.g. in Fig. 8, the shaft side connectors are male and the wire guide side connectors are female). [0089] In another exemplary context used herein, "inner" and "outer" can be used to convey radial directions, particularly directions perpendicular to the axial direction of the wire guide axis. In an exemplary context, "inner" and "outer" surface are used when referring to different surfaces of a connector, such as an inner conical surface (or conical surface between the axis and outer surface) of a connector and an outer surface (for example a surface located between an inner conical surface and a radially outer edge) of a connector.

[0090] Herein "conical" can refer to: a cone shaped structure; and/or a frustum cone shaped structure, which may or may not be hollow. Furthermore "conical" can also refer to a cone shaped structure formed by segments of a cone, especially segments formed by longitudinal segments of a cone or frustum cone (longitudinal segments in the sense that the cone segments are cut from a cone along a plane parallel to the symmetry axis of the cone).

[0091] As a matter of clarity, a conical section as used herein is not to be confused with a conic section which may be understood as a two dimensional curve; for example a conical section, herein, has a three dimensional form. For example, the geometrical form of a conical section, as used herein, can be formed by cutting a solid or hollow cone by a plane oriented parallel to the cone axis. For example two conical sections can be formed by one cut through the center of the cone. Three can be formed by three cuts, e.g. at 120 degrees, each cut going through half the cone, and each cut meeting at the axis of the cone.

[0092] Particularly, in the case of a clamping system including a hydraulic system as a holding mechanism and/or automated clamping, the shaft side connectors can be female. Beneficial of the shaft side connectors being female is that a shorter distance between the connector and a bearing (for example, a bearing on the shaft that may connect the shaft to a motor and/or frame) is possible. Accordingly, the radial load is closer to the bearing, leading to a longer bearing life time. In the case of a holding mechanism that includes a central tensioning screw, for example a manual clamping or manual holding mechanism, the shaft side connector can be male.

[0093] In the present disclosure, "bearing" is used to mean a machine, component, or structural part that supports another part. Alternatively or additionally, a "bearing" is a support, guide, or locating piece for a rotating (or reciprocating) mechanical part. Further, a "bearing" may be understood as a machine element that allows one part to bear (support) another. In the present disclosure, "bearing" and "connector" may be used synonymously. [0094] It is apparent, in comparing Fig. 7 and 8, that at least one of the first shaft side connector 502 and/or the second shaft side connector 505 is movable axially with respect to the other, so that the wire guide 200 can be connected and disconnected, and/or engaged and disengaged. Due to the position, shape, and type of the connectors, the wire guide can be rapidly replaced, for example when it is worn out.

[0095] Fig. 8 illustrates a wire guide and clamping assembly of a wire saw system, according to embodiments described herein. Fig. 8 also illustrates, in comparison to Fig. 7, an alternative pairing of the connectors, with the shaft side connectors (for example, the first shaft side connector 502 and the second shaft side connector 505) being male connectors and the wire guide side connectors (for example, the first wire guide side connector 503 and the second wire guide side connector 504) being female. Complementary pairs of connectors are adapted to abut, and/or mate. Fig. 8 illustrates, according to an embodiment, a connected configuration of the wire guide assembly, e.g. the wire guide 200 is engaged and two sets of complementary connector pairs (for example, the first shaft side connector 502 and the first wire guide side connector 503 as well as the second wire guide side connector 504 and the second shaft side connector 505) mate, i.e. abut. As a matter of terminology, when one of a complementary pair is referred to as a connector, then the other may be referred to as a complementary connector. Herein, "complementary connector" is synonymous with "complementary bearing", "counter bearing", and the like.

[0096] It is contemplated that given a shaft side connector such as first shaft side connector 502 and/or the second shaft side connector 505, the first wire guide side connector 503 and the second wire guide side connector 504 are complementary connectors which may be a component of the wire guide 200. According to some embodiments, the first wire guide side connector 503 and the second wire guide side connector 504 may be a surface, e.g. a surface of the wire guide. Alternatively, the first wire guide side connector 503 and the second wire guide side connector 504 may be a separate connector, connectable to each of the wire guide 200 and the first shaft side connector 502 and/or the second shaft side connector 505 2, respectively. In an embodiment which may be combined with any other embodiment, a shaft 60, as exemplarily illustrated in Fig. 8 may be regarded as a component of the wire saw system, and/or a component of the clamping assembly. Furthermore, the shaft 60 may be regarded as a single shaft, or a plurality of shafts such as a pair of shafts, e.g. a motor side shaft and a freely rotating shaft. In an embodiment which may be combined with any other embodiment, the shaft may extend through wire guide 200, e.g. through the center of the wire guide 200.

[0097] Fig. 9 shows a connector 150 according to embodiments described herein. For example, the connector 150 is at least part of a clamping assembly for connecting to a wire guide 200, particularly to a cylindrical wire guide, of a wire saw system as described herein. The connector 150 includes an outer surface 30 (outer being a direction pointing away from the center of the connector 150) which is at least substantially normal to the axis 10, i.e. the outer surface 30 faces the wire guide 200. The outer surface is adapted to abut a complementary outer surface 31A of a complementary connector 151 and/or complementary surface of the wire guide 200. The complementary outer surface 31A may, for example, be at least substantially normal to the axis 10 and face the connector 150. When connected, a load and/or force can be transmitted through the contact made by the outer surface 30 and the complementary outer surface 31 A. The outer surface 30 and/or complementary outer surface 31A may be referred to as a crown contact face, especially when in contact to its complementary surface.

[0098] In a connected configuration, according to an embodiment, an axially directed load can be transmitted through the outer surfaces 30 and the complementary outer surface 31 A, i.e. the crown contact face. Transmitting the axial load through the outer surface 30 and the complementary outer surface 31 A may improve the axial support of the wire guide 200. Furthermore, improved axial support increases the stability of the wire guide and enhances alignment stability and precision of the position of the wire and/or wire web. In an embodiment, radially directed loads are not transmitted through the outer surface 30 and the complementary outer surface 31 A, i.e. particularly axial loads are transmitted through the outer surface 30 and the complementary outer surface 31A which are substantially normal to the axis 10.

[0099] In an embodiment, the outer surface 30 is at a shorter radial distance from the axis than the grooved surface of the wire guide. The outer surface is parallel to the plane of rotation (normal to the axis 10 of rotation), which can result in axial contact forces arising between the outer surface 30 and its complementary outer surface 31 A.

[00100] In an embodiment, the connector 50 has a conical surface 40 between the outer surface 30 and the axis 10 (in other words the outer surface 30 is arranged at a greater radial distance from the axis than the conical surface is). The conical surface 40 is adapted to abut, e.g. mate with, a complementary surface 41 A of the complementary connector 151 and/or wire guide 200, particularly in an engaged or connected configuration. In an embodiment, in a connected configuration, radially and axially directed loads are transmitted through the conical surface 40 and the complementary surface 41 A, particularly a complementary conical surface. An aspect of having the conical surface between the outer surface 30 and the axis 10, according to an embodiment, is that the outer surface 30 transmits mainly axial loads at greater radial distance from the axis 10. This can improve the axial support of the wire guide, particularly in comparison to clamping assemblies for wire guides which utilize a swivel joint.

[00101] For example, the outer surface 30 of the connector 150 and the complementary outer surface 31A abut when in a connected configuration. Due to the abutment, particularly of the outer surfaces 30 and the complementary outer surface 31 A, the axial position of the wire guide 200 (particularly the wires that are guided by the grooves of the wire guide) is precisely controlled and/or known, particularly in regard to the axial position of the wire guide and/or wire(s). Accordingly, more uniform wafers can be cut.

[00102] In an embodiment which may be combined with any other embodiment, the conical surface 40 is disposed symmetrically about the axis 10. In another embodiment which may be combined with any other embodiment, the connector 150 is hollow. In another embodiment which may be combined with any other embodiment, the outer surface 30 is annularly shaped, whether a continuously annular shape or one comprising segments of a ring. Segments may allow for some expansion and contraction of the connector due for example to heating/cooling, while minimizing damage to the connector and/or its complement. In another embodiment which may be combined with any other embodiment, the outer surface 30 is adjacent to the conical surface 40. In an embodiment which may be combined with any other embodiment, the outer surface is a planar surface, particularly one normal to the axis 10. A planar outer surface can, for instance, improve axial support of the wire guide, particularly in comparison to wire guides supported by swivel joints.

[00103] Fig. 10 illustrates a connector 150 according to an embodiment which may be combined with any other embodiments described herein. The outer surface 30, which can be substantially normal to the axis 10 can be an annular ring or multiple arc-shaped components together forming a ring. According to an embodiment, the outer surface 30 is a smooth and/or unruffled surface.

[00104] According to an embodiment, which may be combined with any other embodiment, the conical surface 40 can include a deformable/flexible material and/or layer of deformable/flexible material. The material can be, for example, a steel alloy, such as those with a good surface hardness, ceramic, and/or carbon fiber reinforced polymer (CFRP), and combinations thereof. A conical surface 40 which has a deformable material can result in more intimate contact between the complementary connectors in a connected configuration. At least one of increased axial and radial support of the wire guide 200 is achieved. For example, a soft, i.e. deformable, conical surface 40 may allow more intimate contact of the outer surface 30 with the complementary outer surface 31 A.

[00105] According to embodiments, and not limited to the embodiment of Fig. 10, the connector 150, particularly the space opposite to the wire guide behind the conical surface, can be hollow, which can increase the deformability of the conical surface. Substantially or fully solid connectors are also contemplated, particularly those using a deformable and/or flexible material.

[00106] Optionally, in an embodiment which can be combined with any other embodiment, the conical surface of a male connector is at least slightly bigger than the complementary surface, particularly the complementary conical surface of the female connector. A slightly bigger male connector, in some embodiments, improves contact between complementary surfaces, particularly complementary conical surfaces. In this context, a slightly bigger male connector means that the maximum diameter of the conical surface (in a direction taken parallel to the outer surface 30) of the male connector is from about 0.001% to about 0.01% larger than the maximum diameter of the complementary surface of the complementary (female) connector, or from about 0.003% through about 0.005% larger.

[00107] In an embodiment, a portion of the outer surface 30, which in the connected configuration abuts the complementary outer surface 31 A, is at a relatively high radial distance from the axis, such as from about 2/3 of the radial distance from the axis 10 to the radially outer edge 90 of the connector 150. In particular, a conical surface 40 may lie between the outer surface 30 and the axis 10. Optionally, a central surface intersects the axis 10, and may be normal to the axis, and may also be adapted to abut a complementary central surface of a complementary connector. Both female (such as illustrated in the embodiments explained in view of Fig. 7) and male (such as illustrated in the embodiments explained in view of Fig. 8) type connectors are envisaged.

[00108] In an embodiment, a portion of the outer surface 30, for instance the radially innermost or outermost portion thereof, may be from about 65%, 70%, 75%, and/or 80% of the distance from the axis 10 to the radially outer edge 90 of the connector 150. The outer surface 30, particularly its placement as described, can enhance the stability of the wire guide. For example, the outer surface 30, located between the radially outer edge 90 of the connector 150 and the conical surface 40, can minimize and/or prevent bending of the wire guide 200 depicted in Fig. 13, as exemplarily indicated by the first angle 85 and the second angle 86. Consequently, for instance, more uniform wafers can be cut, there is a decreased risk of wire breakage, and/or the wear rate on components such as the wire guide 200 is reduced.

[00109] According to embodiments, which can be combined with other embodiments described herein, the outer edge of the conical surface 40, which may be next to the inner edge of the outer surface 30, is located at from about 65% to 85%, or from about 70% to about 80%, such as about 75% of the distance to the radially outer edge 90 of the connector 150 from the axis 10.

[00110] In an embodiment, the male connector includes an outer surface 30 which may or may not be part of the main body 65. According to an embodiment, the outer surface 30 is substantially normal to the axis 10, adapted to abut a complementary outer face of a complementary connector. The connector 150 may further optionally include a central face, substantially normal to and intersecting the axis 10.

[00111] Fig. 11 illustrates a view of a connector 451 according to an embodiment. A feature combinable with all other described features/embodiments described herein depicted in Fig. 11 is the conical surface 40 which includes conical sections 412.

[00112] For instance, the conical sections may have gaps between them to allow deformation/flexing, especially radially directed deformation/flexing of the conical sections 412, conical surface 40, and/or connector 150, particularly in a connected configuration, i.e. connected to a complementary connector. Having 1, 2, 3, 4, 5, 6 or more conical sections 412 is contemplated. In an embodiment, the conical sections as well as the conical surface are disposed symmetrically about the axis 10, which is normal to the view provided by Fig. 11, and coincides with the center of symmetry.

[00113] Fig. 12 illustrates a view of a connector 452 according to an embodiment. A feature which can be combined with all other embodiments described herein and depicted in Fig. 12 is the outer surface 30 which includes outer surface sections 453, e.g. arc shaped sections. For instance, the outer surface sections 453 may have gaps between them. Having 1, 2, 3, 4, 5, 6 or more outer surface sections 453 is contemplated. In an embodiment, the outer surface sections 300 as well as the outer surface 30 are disposed symmetrically about the axis 10, which is normal to the view provided by Fig. 12, and coincides with the center of symmetry.

[00114] Fig. 13 depicts a first angle 85 and a second angle 86 associated with misalignment of the clamping assembly and/or bending of the wire guide. The connector(s) and/or clamping assembly, disclosed herein, reduce misalignment and reduce the first angle 85 and the second angle 86 due to the stiffness of the connection, particularly in comparison to previously known clamping assemblies such as ones utilizing a swivel joint interface. For instance, a steel wire guide using a swivel joint interface may not be precise enough during the entire cutting operation cycle of the wire saw. A clamping assembly utilizing a connector with an outer surface 30 normal to the axis 10 particularly reduces misalignment.

[00115] Fig. 14 illustrates a holding mechanism 70, 71 (which is a feature able to be combined with any embodiment herein) for a clamping assembly, according to embodiments described herein. According to embodiments, a clamping assembly includes a holding mechanism 70, 71 such as a pneumatic or hydraulic holding mechanism. Alternatively or additionally, the holding mechanism 70, 71 comprises a screw. For instance, the holding mechanism 70, 71 may allow for engagement and disengagement of the wire guide 200 from the first shaft side connector 502 and the second shaft side connector 505, e.g. the holding mechanism allows for movement of a connector, especially a shaft side connector, particularly during engagement and/or disengagement. Alternatively or additionally, the holding mechanism 70, 71 ensures contact between the contact faces on each side of the wire guide, i.e. ensuring contact between the outer and inner connectors (i.e. the shaft side and wire guide side connectors, respectively). [00116] In an embodiment, axial support and torque transmission are separated from radial support, allowing a precise radial and axial run-out (e.g. of the wire and/or wire web). In an embodiment, the holding mechanism 70, 71 applies an axial force of about 200 kN, for example from about 50 kN through about 500 kN, or from about 100 kN through about 300 kN, or from aboutl50 kN through about 250 kN. In comparison, the force of the wire on the wire guide may be about 25 N for each wire or wire segment, applied perpendicularly to the clamping force, and totals about 100 to 150 kN.

[00117] According to an embodiment, a holding mechanism 70, 71, particularly one that includes a screw, the wire guide may include a central hole which may be threaded.

[00118] In an embodiment, which may be combined with any other embodiment described herein, the holding mechanism 70, 71, particularly a holding mechanism that applies an axial force, holds the connecting assembly in a connected configuration. For example, the holding mechanism 70, 71 applies an axial force which results in an axial contact force between the outer surface 30 of the first shaft side connector 502 and the complementary outer surface 31A of the complementary first wire guide connector 503 as well as in an axial contact force between the outer surface 30 of the second shaft side connector 505 and the complementary outer surface 31A of the second wire guide side connector 504. Furthermore, the conical surface 40 and the complementary surface 41A of the wire guide 200 may have a contact force with both axial and radial components, the combination of axial and radial components resulting from the conically arranged interface, and which may arise although the holding mechanism 70, 71 applies an axial force.

[00119] Fig. 15 illustrates a cross-section of a wire guide 200, comprising a carbon fiber reinforced polymer (CFRP) section 116 and optional flanges 110, according to an embodiment. CFRP has desirable thermal properties such as low and/or controlled thermal expansion, which can possibly reduce or eliminate the need for cooling of the wire guide 200. CFRP can be used for all embodiments described herein. Additionally, CFRP can reduce the moment of inertia and mass of the wire guide 200, and may be particularly useful in combination with the other features described herein.

[00120] According to embodiments which can be combined with other embodiments described herein, the optional flanges 110 may be made of steel, steel alloys, ceramics, and/or CFRP, for example. The flanges may be adapted to allow the attachment of inner connections, or may alternatively be regarded as the inner connections; for example the optional flanges 110 may have an outer surface (which can abut the outer surface of the shaft side connector in a connected configuration), the outer surface being normal to the axis 10, and a surface complementary to the conical surface of the shaft side connectors. Optionally, the wire guide has an outer shell on which the wire grooves are formed, although it is also contemplated that grooves are formed directly on the CFRP section.

[00121] Fig. 16 illustrates a wire guide assembly in a connected configuration, according to an embodiment, with schematically illustrated supports 127 and also illustrates an ingot 600. The possible thermal expansion and contraction of the ingot 600 is represented by the arrows 135. The expansion (contraction) of the wire guide and/or clamping assembly is illustrated with the lower arrow 335. In the connected configuration, the wire guide 200 is contacted (directly or indirectly) by the connectors, for example the first shaft side connector 502 and/or the second shaft side connector 505.

[00122] For example, as in Fig. 16, the schematically illustrated supports 127 provide stiffness and support so that dilation of a wire guide, particularly a steel one, would be toward the right, e.g. toward a "free" bearing box; and as according to the illustration of Fig. 13, the dilation of the silicon ingot would be in both (opposite) axial directions, left and right in Fig. 13.

[00123] According to embodiments described herein, a CFRP based wire guide, particularly one utilizing a clamping assembly disclosed herein, reduces or eliminates the effects of dilation, e.g. by the CFRP based wire guide having a smaller thermal expansion coefficient and/or one more similar to that of the ingot. A CFRP based wire guide, particularly one utilizing a clamping assembly disclosed herein, therefore can, according to embodiments, reduce deleterious effects of thermal expansion and other alignment factors on the quality (i.e. uniformity, thickness uniformity) of wafers cut with the wire saw.

[00124] The clamping assembly according to embodiment as described herein can beneficially be used within the wafer sawing system as described herein. Accordingly, embodiments of the clamping assembly as described herein can beneficially be used in a method of sawing an ingot as described in herein. [00125] According to embodiments described herein, a clamping assembly for connecting to a wire guide 200, particularly a cylindrical wire guide, is provided. The clamping assembly can be for a wire saw system 1000 as described herein. The clamping assembly includes: a shaft-side connector, adapted to connect to a shaft of the wire saw system, the shaft having an axis 10 of rotation, wherein the shaft- side connector includes: an outer surface 30 which is normal to the axis 10 and adapted to abut a complementary outer surface 31A of a complementary connector of the wire guide 200, and a conical surface 40 between the outer surface 30 and the axis 10, the conical surface 40 being disposed symmetrically about the axis 10, and adapted to abut a complementary surface 41A of the wire guide.

[00126] According to embodiments of the clamping assembly, which can be combined with other embodiments described herein, the outer surface 30 is planar.

[00127] According to embodiments of the clamping assembly, which can be combined with other embodiments described herein, the outer surface 30 is adjacent to the conical surface 40 and/or annularly shaped.

[00128] According to embodiments of the clamping assembly, which can be combined with other embodiments described herein, a portion of the outer surface 30 is located at a distance of at least about 65%, 70%, 75% or 80% of the radial distance from the axis 10 to a radially outer edge 90 of the shaft-side connector, for example a first shaft side connector 502 and/or a second shaft side connector 505.

[00129] According to embodiments of the clamping assembly, which can be combined with other embodiments described herein, the conical surface 40 of the shaft-side connector comprises a deformable material.

[00130] According to embodiments of the clamping assembly, which can be combined with other embodiments described herein, the conical surface 40 comprises 1, 2, 3, or 4 conical sections.

[00131] According to embodiments of the clamping assembly, which can be combined with other embodiments described herein, the shaft side connector is hollow, and/or the shaft side connector is female. [00132] According to embodiments of the clamping assembly, which can be combined with other embodiments described herein, wherein the clamping assembly further includes a holding mechanism 70, 71 selected from a hydraulic system, a pneumatic system, a screw, and combinations thereof.

[00133] According to embodiments of the clamping assembly, which can be combined with other embodiments described herein, wherein the clamping assembly further includes the shaft which is connected to the shaft side connector.

[00134] According to embodiments described herein, a clamping assembly for connecting to a wire guide 200, particularly a cylindrical wire guide, is provided. The clamping assembly can be for a wire saw system 1000 as described herein. The wire saw system 1000 is adapted to cut wafers. The clamping assembly includes: a shaft-side connector, adapted to connect to a shaft of the wire saw system. The shaft has an axis 10 of rotation. The clamping assembly includes a complementary outer surface 31A which is normal to the axis 10 and adapted to the outer surface 30 of a complementary connector of the shaft. The clamping assembly further includes a conical surface 40 between the outer surface 30 and the axis 10, the conical surface 40 being disposed symmetrically about the axis 10, and adapted to abut a complementary surface of the complementary connector.

[00135] According to embodiments of the clamping assembly, which can be combined with other embodiments described herein, the conical surface 40 is attached to the wire guide 200 and/or the outer surface 30 is adjacent to the conical surface 40.

[00136] According to embodiments of the clamping assembly, which can be combined with other embodiments described herein, the wire guide 200 includes a carbon fiber reinforced polymer section.

[00137] According to embodiments of the clamping assembly, which can be combined with other embodiments described herein, the outer surface 30 is annularly shaped, the outer surface 30 optionally including 1, 2, 3, or 4 sections.

[00138] According to embodiments, which can be combined with other embodiments described herein, a wire saw system 1000 having at least one clamping assembly according to any embodiments described herein is provided. [00139] In the following, embodiments of the wire bow monitoring system 160, as exemplarily shown in Figs. 2 and 3 are described. Further, embodiments of a method for monitoring a wire bow in a wire saw system are described.

[00140] Fig. 17 shows an exemplary embodiment of the wire bow monitoring system 160 for the wire saw system according to embodiments described herein. The wire bow monitoring system includes at least one sensor arrangement 20. The at least one sensor arrangement 20 is adapted to be positioned adjacent to a wire of the wire saw system and is adapted to detect a bow of the wire. By gaining information about the wire bow with the wire bow monitoring system as described herein, automatic adjustment of the cutting process in real time by the wire saw system as described herein may be provided. Further, the wire bow measurement can be used as an indicator for cutting efficiency. The information about a bow provided by monitoring of a wire bow is particularly useful to adjust an ingot feeding speed and/or a cutting speed of the wire. Accordingly, wear and breakage of the wire can be minimized and/or throughput and cut yield may be maximized.

[00141] The at least one sensor arrangement includes at least one sensor 228 selected from the group of an inductive sensor, a capacitive sensor and a contact sensor. According to embodiments of the wire bow monitoring system 160, which can be combined with other embodiments described herein, the at least one sensor may be arranged above the wire web. Particularly, the at least one sensor may be arranged in longitudinal direction of the wire of the wire web. Further, the at least one sensor may include multiple sensors which are arranged parallel to each other. Particularly, the multiple sensors may be arranged adjacent to each other, wherein each sensor may be arranged for sensing a different wire of parallel wires of the wire web. The inductive sensor and the capacitive sensor can be adapted to sense the vicinity of the wire if it is iron based. The at least one sensor may be digital or analog. The measurement outcome, also called "measurement result" or "measurement" herein, of the at least one inductive or capacitive sensor may be continuous (in the case of the analog sensor) or digital (in the case of a digital sensor). A continuous outcome may be an indication for the absolute distance between the sensor and the wire, for instance, with m denoting the measurement outcome, and x denoting the distance between the sensor and the wire, x may be represented as function of m, i.e., x=f(m). According to some embodiments, this function is linear. [00142] In those embodiments where the outcome is digital, the sensor may respond with, for instance, 0 if the distance between the sensor and the wire is below a threshold distance, and the sensor may respond with 1 if the distance is above the threshold value. The threshold distance, also called "threshold value" herein, may be pre-set, for instance by an operator during or before the cutting process, or it may correspond to the sensing distance of the sensor, i.e., the sensor is capable of detecting the presence of the wire only up to the sensing distance. For instance, the threshold value may be between 0.1 mm and 1.0 mm, particularly between 0.2 mm and 0.6 mm.

[00143] The term "digital sensor" may be understood as any arrangement, which includes a sensor that provides a digital measurement outcome. The provision of a digital sensor is particularly beneficial when a multitude of sensors, which are provided with measurement outcomes, are evaluated jointly.

[00144] According to embodiments, the at least one sensor arrangement includes a plurality of sensors. In particular, all sensors of the plurality of sensors may be of the same sensor type. For instance, the at least one sensor arrangement may be provided either with a plurality of inductive sensors, or a plurality of capacitive sensors, or a plurality of contact sensors. The one or more sensors of the present disclosure can be in communication with a control unit, such as control unit 1350 in Fig. 17. The communication may particularly be a data communication, in particular from the sensor to the control unit wherein the one or more sensors provide the control unit with the measurement results.

[00145] The control unit may evaluate the one or more measurement results. The control unit may additionally or alternatively trigger a reaction. According to embodiments described herein, the control unit is adapted to be in communication with the wire saw device for initiating a reaction of the wire saw device as a response to the bow measurement results. According to embodiments, the control unit, such as control unit 1350 of Fig. 17, is part of the electrical control system 1300 control of the wire saw system as described herein. It is also possible that the wire bow monitoring system is provided with a separate control unit that is in data communication with the electrical control system 1300 of the wire saw system as described herein.

[00146] The provision of several sensors on the at least one sensor arrangement as illustrated in Fig. 17 (where four sensors are depicted) may particularly be advantageous to measure the presence of a bow in the wire and a value corresponding to the dimension of the bow. For instance, all of the sensors may be either inductive sensors or capacitive sensors. The value corresponding to the dimension may particularly be an angle of the wire as compared to a wire orientation in an unstressed situation of the wire, as will be exemplified below in more detail.

[00147] As exemplarily shown in Fig. 17 and as explained above, the wire 11 can be guided by wire guides, particularly the first wire guide 112 and the second wire guide 114. As outlined above, the wire provided between the first wire guide 112 and the second wire guide 114 forms the wire web in the cutting zone of the wire saw system. With exemplary reference to Fig. 17, a workpiece, e.g. an ingot 600 is mounted to a support table 312, which is configured to be moved against the wire 11, particularly against the wire web, in order to cut the ingot. For example, the support table 312 can be connected to an ingot feeding system as described herein.

[00148] The wire guides may be adapted to rotate in order to transport the wire. The wire guides are normally configured to rotate at a circumferential speed (i.e., the speed at the outer circumference) of at least 0.1 m/s or even 40 m/s. For example, the wire saw can be operated between 20 m/s and 25 m/s during standard operation whereas the speed may be smaller during start and stop. Higher speeds, such as of 26 m/s or 40 m/s can also be applied. Also, in the event of a back and forth movement of the wire, the wire is decelerated from time to time in order to accelerate it in the opposite direction.

[00149] During cutting, the wire moves substantially along its longitudinal length. The term "substantially" may particularly embrace vibrations or the like. The wire motion can alternatively be in a reciprocating manner, in which the motion of the wire along its length is in the periodically reversed direction. In operation, the wire is brought into contact with a workpiece to cut the workpiece, for instance, into a plurality of wafers.

[00150] According to different implementations, the wire forming a wire web can be moved relative to the workpiece, the workpiece can be moved relative to the wire or wire web, or the wire and the workpiece can both be moved relative to each other.

[00151] When the workpiece and the wire (such as the wire web) are pressed relatively against each other, the resulting force exerted by the workpiece on the wire causes the wire to become bowed. The orientation of the wire bow coincides with the cutting direction. When the wire bow increases too much a breakage of the wire may occur. Accordingly, embodiments described herein allow the detection of a bow before it becomes too large, and furthermore, allow triggering an adequate reaction in order to avoid a breakage of the wire. Such a reaction could be, for instance, the reduction of the speed of the workpiece against the wire and/or an increase in the wire speed. Further reactions could encompass an amendment in the amount of provided slurry or the slurry composition etc.

[00152] According to embodiments of the wire bow monitoring system 160 described herein, as exemplary shown in Fig. 17, the at least one sensor arrangement 20 is configured to be positioned adjacent to the wire 11 and may include a sensor board 46 with several sensors mounted to it. The number of sensors can be at least 2, at least 4, or even at least 8, 10 or even 16. The sensors are configured to detect the wire bow. The data measured and collected by the sensors can be forwarded to the control unit 1350 where it may be further processed, such as evaluated. For instance, logic levels (i.e., 0 or 1 outcomes) of each sensor may be used to monitor a progression of the wire bow.

[00153] Although not explicitly shown, according to embodiments which can be combined with other embodiments described herein, the wire bow monitoring system may include two sensor arrangements, for example a first sensor arrangement and a second sensor arrangement. The first sensor arrangement and the second sensor arrangement may be configured according to embodiments of the at least one sensor arrangement as described herein. For example, the first sensor arrangement may be arranged adjacent to the first wire guide and the second sensor arrangement may be arranged adjacent to the second wire guide. In particular, as exemplarily shown in, the first sensor arrangement may be arranged on a first side of the ingot and the second sensor arrangement may be arranged on a second side of the ingot, opposing the first side of the ingot.

[00154] Fig. 18 shows the same embodiment as Fig. 17, wherein the wire (web) undergoes a bow due to the ingot being pressed onto the wire (web) in the cutting direction 601. For illustration purposes, only one sensor arrangement is shown in Fig. 18. The principle of the bow measurement as exemplarily described in connection with Fig. 18 for one sensor arrangement may also apply to embodiments including more than one sensor arrangement. As exemplarily illustrated in Figs. 17 and 18, according to embodiments with several digital sensors, the logic states of all the sensors can be the same if there is no wire bow or only a small wire bow. "Small" in this context means that the wire bow does not exceed a threshold value for the wire-sensor distance.

[00155] During the cutting process, the wire bow may increase and the logic states of one or more of the sensors may also change. For instance, the two sensors closer to the workpiece (i.e., in the embodiments illustrated with respect to Figs. 17 and 18, the two sensors to the right) may indicate the result that the distance between these sensors and the wire is above the threshold value whereas the two sensors further away from the workpiece (i.e., the two sensors to the left in Figs. 17 and 18) may sense a distance between the wire and the sensor that is below the threshold value. From these results, it is possible to gain information about the bow dimension of the wire, in particular, about the angle alpha (a) (depicted in Fig. 18) between the wire in the actual bowed position and a non-bowed wire, or the absolute bow length L that will be discussed below in more detail.

[00156] For instance, if the at least one sensor arrangement includes four sensors in the longitudinal wire direction as illustrated in Figs. 17 and 18 (notwithstanding the number of sensors in the perpendicular direction, as will be discussed with respect to the embodiments illustrated in view of Fig. 19), and if the sensors are digital sensors, the threshold value of the sensors may be selected such that the following information can be gained:

[00157] As shown in the table, if all sensors show a 0 response, there is no wire bow or only a small wire bow (such as below 2°). If the sensor closest to the workpiece measures a distance above the threshold value resulting in a measurement result 1, whereas the distance between the other sensors and the wire is below the threshold value, i.e. 0, then this result can be interpreted as an angle alpha (a) of larger than 2° and below 4°. Similar considerations apply to the further measurement results depicted in the further rows of the shown table. Once all sensors respond with 1, the distance between all sensors and the wire is above the threshold value which, in the shown non-limiting example of the table, has to be interpreted as a bow angle of more than 8°. Evidently, at least this information should trigger a reaction such as an amendment of at least one wire saw device operation parameter. The embodiment with the four sensors in the longitudinal length of the wire and their threshold settings resulting in the angle alpha (a) distribution as shown in the table is only for illustrative purposes. It is evident to the skilled person that any other constellation and values may be comparably suitable.

[00158] Whereas the example above uses the angle alpha (a) as an indication for the dimension of the wire bow, it is also possible to deduce the absolute bow length L from the measurement results. The absolute bow length L refers to the maximal deviation of the wire from its rest position in the cutting direction. The absolute bow length L is exemplarily illustrated in Fig. 18 and denoted with reference number 140.

[00159] For instance, if the at least one sensor arrangement includes four sensors in the longitudinal wire direction as illustrated in Figs. 17 and 18 (notwithstanding the number of sensors in the perpendicular direction), and if the sensors are digital sensors, the threshold value of the sensors may be selected such that the following information can be gained:

Signal Signal Signal Signal

sensor 1 sensor 2 sensor 3 sensor 4 Interpretation

0 0 0 0 L < 3 mm

0 0 0 1 3 mm < L < 6 mm

0 0 1 1 6 mm < L < 9 mm

0 1 1 1 9 mm < L < 12 mm

1 1 1 1 L > 12 mm

any other signal constellation failure

[00160] Furthermore, the at least one sensor arrangement or the wire saw system as described herein may be configured to trigger a reaction, such as an amendment of the operational status of the wire saw, such as at least one operation parameter, in dependence of the measurement results. With reference to the example illustrated with respect to the tables above, no reaction may be triggered as long as the bow angle alpha (a) is below 6°, or the absolute bow length is below 9 mm. Once the alpha (a) exceeds 6°, or the absolute bow length L exceeds 9 mm, the speed of the wire may be increased, such as by 10%, and/or the cutting speed (i.e., the moving speed of the workpiece in the cutting direction) may be reduced, such as by 10%. Once the alpha (a) exceeds 8°, or the absolute bow length L exceeds 12 mm, the speed of the wire may be increased even more, such as by at least 20%, and/or the cutting speed may be reduced even more, such as by at least 20%. Alternatively, once a maximal bow angle is measured (such as at least 8° or at least 12 mm absolute bow length in the present example), and not limited to the present example, the wire saw system may be halted and/or an operator may be alerted.

[00161] It can be understood that any other measurement result, for example that all sensors measure the distance between them and the wire as being below the threshold value with one intermediate sensor, or a sensor further away from the workpiece than at least part of the other sensors, indicating a distance above the threshold value, represents a failure of the system. This is because the bow is always in the direction of the cutting direction. In other words, negative angles alpha (a) neither represent a situation that happens in practice nor is it possible that a sensor senses a smaller distance than its neighbor further away from the workpiece. [00162] By using the information about the logic states of the sensors as described above, the control unit 1350 may determine the value of the wire bow and may control the wire saw device so as to avoid a breakage of the wire.

[00163] According to embodiments of the wire bow monitoring system 160 described herein, the control unit 1350 is configured to adjust a wire speed and/or an ingot feeding speed depending on the wire bow. The control may be a feedback loop control.

[00164] According to embodiments of the wire bow monitoring system 160 described herein, the at least one sensor arrangement further includes at least one sensor board, wherein the sensors are mounted to the sensor board in at least two rows. An exemplary arrangement is illustrated in Fig. 19 wherein four rows of sensors in an orientation perpendicular to the wire 11 are illustrated, and four rows of sensors in an orientation substantially parallel to the wire orientation are illustrated.

[00165] As used herein in context with the wire bow monitoring system, the term "row of sensors" refers particularly to an arrangement where the sensors of different rows are spaced apart from each other, for example in a direction substantially perpendicular to the wire orientation and/or an orientation substantially parallel to the wire orientation. "Substantially" in this context may include a deviation of 20°, more particularly 10°.

[00166] Fig. 19 shows a schematic view of the sensor board 46 with 4x4 sensors mounted to it. According to embodiments, the overall numbers of sensors can be calculated as k times n with k and n both being positive integers, wherein, for instance, k denotes the number of sensors in the orientation substantially parallel to the wire orientation, and n denotes the number of sensors in the orientation substantially perpendicular to the wire orientation. For instance, the number of sensors arranged substantially perpendicular to the wire orientation may be at least two, at least four, or at least six. Additionally or alternatively, the number of sensors arranged substantially parallel to the wire orientation may be at least two, at least four, or at least six. The overall number of sensors may be up to 20 or even 30. Additionally or alternatively, it may be at least 9 or 16.

[00167] As exemplarily illustrated in Fig. 19, the sensors may be positioned in a diagonal pattern on the board. A diagonal pattern may include at least four sensors arranged in a parallelogram-type fashion. In particular, and not limited to any embodiment described herein, each sensor is centered above or below a wire that is different to the wire that all the other sensors are centered above or below.

[00168] According to embodiments, the multitude of sensors can particularly be inductive sensors or capacitive sensors. Inductive sensors are particularly beneficial in that they are insensitive to water, oil, dirt, non-metallic particles, target color, ability to withstand high shock and vibration environments.

[00169] According to embodiments, as exemplary described above, a method for monitoring a wire bow in a wire saw system is provided. The method for monitoring a wire bow includes conducting at least one of an inductive measurement, a capacitive measurement and a contact measurement of a wire. The method furthermore includes detecting a bow of the wire. In particular, detecting may include evaluating the measurement results, in particular by means of a control unit.

[00170] According to embodiments, the control unit controls the wire saw system depending on the data received from the measurement of the at least one sensor arrangement.

[00171] Further, according to embodiments described herein a method for monitoring a wire bow in a wire saw system according to embodiments described herein is provided. The method includes conducting at least one of an inductive measurement, a capacitive measurement and a contact measurement of a wire; and detecting or determining a bow of the wire. Further, the method for monitoring a wire bow may further include controlling a sensor arrangement and/or a wire saw device using the data received from the sensor arrangement.

[00172] According to embodiments described herein, a wire bow monitoring system for a wire saw system 1000 as described herein is provided. The wire bow monitoring system includes at least one sensor arrangement 20 configured to be positioned adjacent to a wire 11 of the wire saw system. The at least one sensor arrangement 20 is adapted to detect a bow of the wire 11. The at least one sensor arrangement 20 can include at least one of an inductive sensor, a capacitive sensor and a contact sensor.

[00173] According to embodiments of the wire bow monitoring system which can be combined with other embodiments described herein, the at least one sensor arrangement 20 includes a plurality of sensors. [00174] According to embodiments of the wire bow monitoring system which can be combined with other embodiments described herein, the at least one sensor arrangement 20 includes at least one of a plurality of inductive sensors, a plurality of capacitive sensors and a plurality of contact sensors.

[00175] According to embodiments of the wire bow monitoring system which can be combined with other embodiments described herein, the at least one sensor arrangement 20 further includes at least one sensor board. The sensors can be mounted to the sensor board 46 in at least two rows.

[00176] According to embodiments of the wire bow monitoring system which can be combined with other embodiments described herein, the sensors are positioned on the sensor board in a diagonal pattern.

[00177] According to embodiments of the wire bow monitoring system which can be combined with other embodiments described herein, at least one sensor is movably and/or pivotably arranged.

[00178] According to embodiments of the wire bow monitoring system which can be combined with other embodiments described herein, the sensors are either digital sensors or analog sensors.

[00179] According to embodiments of the wire bow monitoring system which can be combined with other embodiments described herein, the wire bow monitoring system further includes a control unit 1350 adapted to control the at least one sensor arrangement 20 and/or the wire saw system depending on the data received from the at least one sensor arrangement.

[00180] According to embodiments of the wire bow monitoring system which can be combined with other embodiments described herein, the wire bow monitoring system further includes an actuator adapted to change a distance between the sensor arrangement and the wire; and/or an actuator adapted to rotate the sensor.

[00181] According to embodiments, which can be combined with other embodiments described herein, a wire saw system is provided including a wire bow monitoring system according to embodiments described herein. [00182] According to embodiments, which can be combined with other embodiments described herein, a method for monitoring a wire bow in a wire saw system as described herein is provided. The method for monitoring a wire bow, includes conducting at least one of an inductive measurement, a capacitive measurement and a contact measurement of a wire; detecting a bow of the wire,

[00183] According to embodiments of the method for monitoring a wire bow, which can be combined with other embodiments described herein, a control unit controls at least one sensor arrangement and/or the wire saw system depending on the data received from the at least one sensor arrangement.

[00184] According to embodiments of the method for monitoring a wire bow, which can be combined with other embodiments described herein, several measurements are conducted synchronously, and the measurement results of the several measurements are jointly evaluated in order to gain information about the wire bow dimension.

[00185] According to embodiments described herein, a method for operating a wire saw system is provided. The method for operating a wire saw system includes: setting at least one wire saw device operation parameter; cutting a workpiece by means of a wire; monitoring a wire bow of the wire according to any embodiments of the method for monitoring a wire bow as described herein; and adjusting the at least one wire saw system parameter if the wire bow exceeds a threshold value.

[00186] In the following, embodiments of a wire monitoring system for a wire saw system as described herein are described.

[00187] As schematically shown in Fig. 20, a wire monitoring system 55 for a wire saw system according to embodiments described herein includes a sensor device 50, a wire positioning system 21, and a first wire holding arrangement 41. According to embodiments, the wire positioning system 21 may be employed for moving a first wire 31 from a first position of the first wire to a second position of the first wire. According to embodiments, the first wire holding arrangement 41 may be configured for holding the first wire 31 at the second position. At the second position of the first wire 31, a physical characteristic of the first wire 31 may be measured by the sensor device 50. The first wire 31 may correspond to the wire supplied from the supply spool 134 to the wire web 111, as exemplarily described in connection with Fig. 3 above.

[00188] According to embodiments, a wire monitoring system 55 may be positioned in a region of the wire saw system in which a single wire is spanned between two rolls, spools or cylinders. For example, as exemplarily shown in Fig. 20, the wire monitoring system 55 may be positioned between the supply spool 134 from which a single wire is supplied to the first wire guide 112. Although not explicitly shown, alternatively the wire monitoring system 55 may also be positioned between the first wire guide 112 and the take-up spool 138. According to embodiments, two or more monitoring systems may be provided, e.g. a first wire monitoring system between the supply spool 134, from which a single wire is supplied to the first wire guide 112, and a second wire monitoring system between a the first wire guide 112 and the take-up spool 138.

[00189] In the present disclosure, a wire positioning system as described herein may be understood as a system capable of transferring at least a portion of a wire of a wire saw from a first position to a second position. In the present disclosure, the expression "wire trajectory" may be understood as the contour the wire describes in space. According to embodiments, the first position of the wire may be a position on a first wire trajectory and the second position may be a position on a second wire trajectory. According to embodiments, the first wire trajectory may be a trajectory of a moving wire or a non-moving wire. According to embodiments, the second wire trajectory may be a trajectory of a moving wire or a non- moving wire. In the present disclosure, a wire trajectory is to be understood as a curve along which the wire is oriented.

[00190] According to embodiments, a wire positioning system as described herein is capable of transferring at least a portion of a wire from a first position to a second position by performing a movement, in particular, along a trajectory which is not parallel to the first wire trajectory. For example, the movement of the wire positioning system for transferring at least a portion of a wire from a first position to a second position can be substantially perpendicular to the first wire trajectory.

[00191] According to embodiments of the wire saw system, at least one of the first wire guide 112 and the second wire guide 114 may be connected to a motor or drive, for example to a first motor 122 and/ or a second motor 124 (shown in dashed lines in Fig. 20). The first motor 122 and/ or the second motor 124 may be adapted for performing a back-and-forth movement of the wire 11. The back-and-forth movement of the wire is denoted with arrow 225 in Fig. 20. The first motor 122 and/ or the second motor 124 driving the wire can be motors having a small momentum in order to stop and accelerate within a short time period. This is particularly useful in the embodiments of the present disclosure providing a back-and- forth movement. For instance, the direction of wire movement may change with a cycle anywhere between 10 sec up to 60 min. For example, depending on the wire speed, 10 sec may correspond to a forward distance of 50 m, and 60 min may correspond to 50000 m.

[00192] During cutting action, an ingot 600 or a plurality of ingots may be pushed through the wire web 111 in order to slice the ingot or the plurality of ingots. This is exemplarily indicated in Fig. 20 by the arrows below the ingot 600 pointing towards the wire web 111. According to embodiments, one or more ingots may be supported by a table (not shown) which can be moved with a particular speed. In the present disclosure, the speed with which the material to be sawed, e.g. an ingot, is moved relatively to the moving wire is also referred to as material feed rate. The material feed rate in the embodiments described herein may be in the range of 2 μητ/8 to 50 μητ/s.

[00193] According to embodiments, the one or more ingots may be sliced into a multitude of wafers, for example at least 1 or more, particularly 500 or more. According to embodiments, the lengths of the ingots may be in the range of up to 350 mm, in particular in the case of multi-crystalline Silicon, and up to 500 mm, in particular in case of mono- crystalline Silicon.

[00194] After traveling through the wire saw, the wire may exit the operation area of the wire saw at a diameter reduced in comparison to the initial diameter of the wire before the sawing process. In case a wire is used in which an abrasive is provided on the wire as a coating or bonding, e.g. as with diamond wire, the abrasive concentration (e.g. diamond concentration) and/or abrasive repartition (e.g. diamond repartition) may change during the cutting process. The wear of the wire is process dependent. In particular, the higher the cut rate, the higher the resulting temperature, the higher the wire wear. Consequently, as the diameter of the cutting wire and thus the mechanical properties of the wire may change during the cutting process, as a function of time and temperature, the cutting force acting on the ingot by the wire and the abrasion property of the wire changes during the cutting process resulting in undesirable inhomogeneous cutting surfaces of the ingot. Since on the one hand the wire wear increases the wire breakage probability and, on the other hand, the wire usage increases the costs of manufacturing a wafer. By providing a wire monitoring system 55 for the wire saw system as described herein, physical characteristics of the wire can be monitored and the cutting process can be optimized using the measurement data of the physical characteristics. Accordingly, the overall process costs can be minimized.

[00195] According to embodiments of the wire monitoring system described herein, physical characteristics of the wire may be measured during the cutting process. The measuring of physical characteristics of the wire can be carried out at selectable time intervals. In particular, for conducting a measurement of at least one physical characteristic of the wire the cutting process may be stopped, such as after a selectable time interval. Physical characteristics of the wire may be measured acquiring measurement data using the wire monitoring system 55 as described herein.

[00196] The acquired measurement data can then be used for adjusting cutting process parameters. For example, when the wire has experienced a certain degree of wear resulting in a decrease of the diameter, measurement data of the wire diameter can be employed for calculation of mechanical properties of the used wire having a reduced diameter compared to a new wire. Thus, cutting process parameters can be adjusted according to the changing mechanical properties of the wire due to wear. A critical wire diameter below which breakage of the wire is likely to occur may be detected such that the used wire can be replaced by a new wire before damage occurs due to breakage of the wire.

[00197] According to embodiments of the wire monitoring system described herein, with exemplary reference to Fig. 20, the wire positioning system 21 of the wire monitoring system may include two first wire guide pulleys (22, 23), for guiding the first wire 31 between the two first wire guide pulleys in the first position of the first wire 31. At least one first movable positioning pulley 24 may be arranged between the two first wire guide pulleys (22, 23). The at least one first movable positioning pulley 24 may be adapted for carrying the first wire 31 from a first position of the first wire 31 to a second position of the first wire 31, as exemplarily shown in Fig. 21. The at least one first movable positioning pulley 24 can be coupled to an actuator for performing a movement, in particular along a trajectory, in particular a linear trajectory. [00198] According to embodiments the wire monitoring system described herein, as exemplarily indicated in Fig. 22 by the arrow 241, the at least one first movable positioning pulley 24 may be moved between a first position of the first movable positioning pulley 24 and a second position of the first movable positioning pulley 24. As shown in Fig. 21, when the at least one first movable positioning pulley 24 is moved from the first position of the first movable positioning pulley 24 to the second position of the first movable positioning pulley 24, the first wire may be carried from the first position of the first wire to the second position of the first wire. According to embodiments, the first position of the wire may be a position on a first wire trajectory, as exemplarily illustrated in Fig. 20, and the second position may be a position on a second wire trajectory, as exemplarily illustrated in Fig. 21.

[00199] According to embodiments the wire monitoring system described herein, as exemplary shown in Fig. 21 and 22, the two first wire guide pulleys (22, 23) may be arranged on the opposite side of the first wire 31 as compared to the first movable positioning pulley 24. For example, the two first wire guide pulleys may be arranged on one side of the first wire and the first movable positioning pulley may be arranged on the opposite side of the first wire. The two first wire guide pulleys may be fixed in a selectable position.

[00200] According to embodiments of the wire monitoring system described herein, when the first movable positioning pulley is in the first position of the first movable positioning pulley, the first wire can be in the first position of the first wire forming a line between the two first wire guide pulleys. When the first movable positioning pulley is in the second position of the first movable positioning pulley at least a portion of the first wire is transferred from the first position of the first wire to the second position of the first wire. As exemplarily shown in Fig. 30, when the first movable positioning pulley moves towards the second position of the first movable positioning pulley at least two portions of the first wire having different inclined wire orientations may be formed. In particular, the at least two inclined portions of the first wire formed by moving the first movable positioning pulley to the second position of first movable positioning pulley may form sides of a triangle, wherein the base of the triangle can be considered as an imaginary line between the two first wire guide pulleys and the tip of the triangle is the imaginary location at which the two inclined portions having different orientation meet. [00201] According to embodiments the wire monitoring system described herein, with exemplary reference to Fig. 21, the first wire holding arrangement 41 is configured and arranged such that when the first movable positioning pulley 24 has transferred at least a portion of the first wire 31 from the first position of the first wire to the second position of the first wire, at least one of the at least two inclined portions of the first wire in the second position of the first wire may be held by the first wire holding arrangement 41. In the present disclosure the expression "a wire is held by a holding arrangement" is to be understood as the wire is in contact with the holding arrangement. Further, the expression "a wire is held by a holding arrangement" may be understood as the wire is diverted by the holding arrangement. According to embodiments of the wire positioning system, in the second position of the first wire, the first wire can be received by the first wire holding arrangement 41 such that a wire measurement portion 311 of the first wire 31 may be formed.

[00202] According to embodiments of the wire monitoring system 55, as exemplary shown in Fig. 21, when the first movable positioning pulley 24 has carried the first wire to the second position of the first wire the first wire holding arrangement 41 may hold the second position of the first wire 31. The first wire holding arrangement 41 may include a first holding element 43 and a second holding element 44. The first holding element 43 and the second holding element 44 can be configured for receiving the first wire 31. In particular, the first holding element 43 and the second holding element 44 may be configured having a V-shaped recess for receiving the first wire. According to embodiments, the first wire may exert a force to the apex of the recess when the first wire is in the second position. Accordingly, the wire portion of the first wire between the first holding element and the second holding element may be tensioned.

[00203] According to embodiments of the wire monitoring system described herein, the length of the portion of the first wire 31 between the first holding element 43 and the second holding element 44 may be referred to as the wire measurement portion 311. In the present disclosure in context with embodiments of the wire monitoring system described herein, the expression "measurement portion" is to be understood as the portion of the wire in which at least a part of the wire portion between holding elements of a holding arrangement is measured. According to embodiments, the length of the wire measurement portion 311 may be limited by the width W of the sensor device 50. As the length of the measurement portion is decreased, wire vibration of the measurement portion can be more effectively suppressed. According to embodiments, the measurement portion may be below 60 mm, in particular below 50 mm, more particular below 40 mm.

[00204] According to embodiments of the wire monitoring system described herein, not explicitly shown in the figures, the first holding element 43 and second holding element 44 of the first wire holding arrangement 41 may be pulleys. The pulleys may be rotatably mounted on the first wire holding arrangement, such that a measurement of at least one physical characteristic of the wire may be conducted during the cutting process. Accordingly, a wire monitoring system may be provided with which physical characteristics of a wire may be measured during cutting operation of the wire saw.

[00205] According to embodiments of the wire monitoring system described herein, the sensor device 50 may be configured and arranged such that a physical characteristic of the first wire can be measured in the second position of the first wire 31. According to embodiments, the sensor device may be configured and arranged for measuring a wire characteristic of at least a part of the wire in the wire measurement portion 311.

[00206] According to an alternative embodiment of the wire monitoring system 55 as described herein, the first wire holding arrangement 41 can be connected to the sensor device 50 as exemplarily shown in Fig 23. With the exemplary embodiments of the wire monitoring system as shown in Figs. 23 and 24, the wire monitoring system may be moved towards the wire 11 for conducting a measurement. For example, the wire monitoring system 55 may be coupled to an actuator 54 for positioning the monitoring system in a measurement position. In the measurement position the wire to be measured may be tensioned by the first holding element 43 and the second holding element 44 of the first wire holding arrangement 41. As exemplarily shown in Fig. 23, the wire monitoring system 55 may be arranged at a location within the wire saw system which is between the supply spool 134 and the wire supply pulley 101. Additionally or alternatively, the wire monitoring system 55 may be arranged at a location within the wire saw system which is between the take-up spool 138 and the wire receiving pulley 102.

[00207] Further, according to an alternative embodiment of the wire monitoring system 55 as described herein, a second wire holding arrangement 42 including a third holding element 47 and a forth holding element 48 may be connected to the sensor device 50 as exemplarily shown in Fig 24. Accordingly, as exemplarily shown in Fig. 24, the wire between the supply spool 134 and the wire supply pulley 101 and the wire between the take-up spool 138 and the wire receiving pulley 102 may be measured at the same time.

[00208] According to embodiments of the wire monitoring system which can be combined with other embodiments described herein, the sensor device 50 may include a radiation source 51 and a sensor, for example an optical sensor 52. According to embodiments, the radiation source 51 and the optical sensor 52 may be arranged opposite to each other. According to embodiments, the radiation source 51 and the optical sensor 52 may be arranged opposite and parallel to each other having a distance between them of below 30 cm, in particular below 20 cm, more particularly below 15 cm. Also not explicitly shown, the wire measurement portion 311 may be guided through the sensor device, i.e. between the optical sensor 52 and the radiation source 51, substantially perpendicular to the optical path between the optical sensor 52 and the radiation source 51.

[00209] According to embodiments which can be combined with other embodiments described herein, the sensor device of the wire monitoring system may include a radiation source and an optical sensor. The optical sensor may include the capability to process visible radiation. According to embodiments, the optical sensor may be adapted for processing radiation in the extra-optical range, such as infrared, ultraviolet radiation, X-rays, alpha particle radiation, electron particle radiation, and/or gamma rays. According to embodiments, the radiation source for one or more of the listed radiation types may be part of the wire monitoring system. For instance, in the case of an optical sensor that may be adapted to process radiation in the optical range (400-800 nm), environmental light or the use of a LED might act as the respective light source. The optical sensor may be applied in the form of a photo sensor or a CCD-sensor (charged coupled devices).

[00210] According to embodiments which can be combined with other embodiments described herein, the optical sensor may be connected to a data processing unit (not shown) via a cable or wireless connection. The data processing unit can be adapted to inspect and analyze the signals of the optical sensor during operation of the wire saw. If the wire exhibits any physical condition that is defined as non-normal, the data processing unit may detect the change and trigger a reaction. The data processing unit may be connected to or be part of the electrical control system 1300 of the wire saw system 1000 as described herein. [00211] According to embodiments which can be combined with other embodiments described herein, the optical sensor may be adapted to detect a change in at least one physical characteristic of the wire by analyzing the acquired data taken by the sensor device, for example, having an optical sensor e.g. a camera. In case the wire exhibits a thinning, the data processing unit detects the change and may initiate a reaction when the cutting process is continued after the measuring of a physical characteristic of the wire. Accordingly, in case a wire is used in which an abrasive is provided on the wire as a coating or bonding, e.g. as with diamond wire, the data processing unit may detect a change in abrasive concentration (e.g. diamond concentration) and/or abrasive repartition (e.g. diamond repartition) and may initiate a reaction. Such a reaction can be an increase or decrease of the wire speed, a reduction of the material feed rate, a wire tension, and a change of coolant supply rate or an increase of the portion of forward movement of the wire in comparison to the portion of backward movement of the wire during cutting. If a non- acceptable thinning of the wire is detected, i.e. a critical diameter of the wire below which breakage is likely to occur is reached; the reaction initiated by the data processing unit may be providing new wire from the supply spool before the cutting process is continued.

[00212] For instance, the wire might exhibit a physical characteristic such as a wearing, wire diameter, wire homogeneity, diamond concentration and/or diamond repartition which is, according to the data acquired taken by the optical sensor, exceeding or under running a first threshold value. For example a wire inspection system might be programmed to increase the wire speed by a selectable value, such as by at least 10%, the tension of the wire by a selectable value (for reducing the breaking probability), such as by at least 10%, and the back- movements of the wire by a selectable value, such as at least 20%. In addition or alternatively, the wire inspection system might be programmed to reduce the material feed rate by a selectable value, such as by at least 10%. Accordingly, the risk of wire breakage can substantially be avoided. By exactly determining the physical characteristic of the wire it is possible to ensure that the wire is used to the full capacity of the wire to increase the efficiency and cost effectiveness of the cutting process.

[00213] According to embodiments which can be combined with other embodiments described herein, the first holding element and the second holding element ensure that the first wire can be positioned precisely at a predetermined position such that the distance between the first and the optical sensor may be selectable. According to embodiments, the distance between the first wire and/or the second wire and the optical sensor is half the distance from the radiation source to the optical sensor. According to embodiments, the distance between the first wire and/or the second wire and the optical sensor is below 15 cm, in particular below 10 cm, more particularly below 7.5 cm. Accordingly, a reproducible and accurate measurement of a physical characteristic of the first wire and/or the second wire can be realized.

[00214] According to embodiments, which can be combined with other embodiments described herein, the first holding element and the second holding element may be arranged such that the length of the measurement portion of the first wire is minimized. Accordingly, measurement inaccuracies due to wire vibration may substantially be eliminated. According to embodiments, the lower limit of the length of the measurement portion of the first wire is determined by the width of the sensor device. According to embodiments, the width of the sensor device may be about 40 mm, particularly about 35 mm, more particularly below 30 mm.

[00215] Further according to embodiments described herein, a method for monitoring physical characteristics of at least one wire is provided. The method for monitoring physical characteristics of at least one wire may include: moving at least one wire from a first position to a second position; holding the second position of the at least one wire; and measuring physical characteristics of the at least one wire at the second position.

[00216] According to embodiments of the method for monitoring physical characteristics of at least one wire, at least one physical characteristic of the wire may be measured at selectable time intervals. "Physical characteristic" in this respect pertains primarily to the question whether the wire shows large wear or inhomogeneities, or whether the wire has any type of defects, small cracks, ruptures, changes in the metallo graphic structure of the wire (such as grain size etc.), a high level of usage (e.g., a large thinning) or whether dirt sticks to the wire surface.

[00217] According to embodiments of the method for monitoring physical characteristics of at least one wire, the cutting process may be stopped after a selectable time interval for conducting the measurement of at least one physical characteristic of the wire. In the case that the wire's physical condition exceeds a threshold value, the mode of operation may be amended as a reaction thereof or new wire may be provided from the supply spool for continuing the cutting process.

[00218] According to embodiments of the method for monitoring physical characteristics of at least one wire moving at least one wire includes: moving a first wire by carrying the first wire from a first position of the first wire to a second position of the first wire by moving a first positioning pulley of a wire positioning system. The at least one first movable positioning pulley can be coupled to an actuator for performing a movement, in particular along a trajectory, in particular a linear trajectory.

[00219] According to embodiments, the actuator may be operated by a source of energy in the form of an electric current, hydraulic fluid pressure or pneumatic pressure converting the energy into motion. According to some embodiments, the actuator for moving the at least one first movable positioning pulley can be an electrical motor, a linear motor, a pneumatic actuator, a hydraulic actuator or a piezoelectric actuator.

[00220] According to embodiments of the method for monitoring physical characteristics of at least one wire holding the second position of the at least one wire includes holding a first wire in the second position of the first wire. Holding the first wire in the second position may include tensioning of at least a portion of the first wire.

[00221] According to embodiments described herein, the methods for monitoring physical characteristics of at least one wire can be conducted by means of computer programs, software, computer software products and the interrelated controllers, which can have a CPU, a memory, a user interface, and input and output means being in communication with the corresponding components of the wire saw. These components can be one or more of the following components: motors, wire break detection units, wire tracking devices, and the like.

[00222] In the following, embodiments of a wafer cleaning system for a wire saw system as described herein are described.

[00223] Fig. 25A shows a schematic view of an excerpt of a wire saw system according to embodiments described herein including a wafer cleaning system according to embodiments described herein. In particular, Fig. 25A shows a view of the cutting zone of the wire saw system as described herein. According to embodiments of the wafer cleaning system which can be combined with other embodiments described herein, the wafer cleaning system includes a plurality of cleaning nozzles 540 which are configured and arranged for providing a cleaning liquid 544 into a space between adjacent wafers which have been cut from an ingot 600. The cleaning liquid may for example be water, polyethylene glycol (PEG) or any other suitable cleaning liquid.

[00224] In the present disclosure, the expression "providing a cleaning liquid into a space between adjacent wafers from at least one side of the wafers" may be understood as providing cleaning liquid into a space between wafers sawed from an ingot which are separated from each other by slots or sawing gaps. Accordingly, the expression "a space between adjacent wafers" may refer to the slots or sawing gaps between the sawed wafers. Accordingly, the space between sawed wafers may refer to a plurality of spaces between adjacent wafers. Further, the expression "from at least one side of the wafers" in context with "providing a cleaning liquid into a space between adjacent wafers" may be understood as the side of the wafers from which the slots or sawing gaps between the sawed wafers are accessible to cleaning liquid.

[00225] According to embodiments of the wafer cleaning system which can be combined with other embodiments described herein, the at least one cleaning nozzle 540 may be configured for providing a confined jet of cleaning liquid. The confined jet of cleaning liquid may have the shape of a blade. For example, the blade of cleaning liquid may have an extension for providing the cleaning liquid into at least 50 %, particularly to at least 75%, more particularly to at least 95%, particularly 100%, of the space between adjacent wafers from at least one side of the wafers at the same time, i.e. not including a movement of the at least one cleaning nozzle relative to the wafers.

[00226] According to embodiments of the wafer cleaning system which can be combined with other embodiments described herein, the at least one cleaning nozzle 540 may be configured for varying the position of the confined leaning liquid jet. For example, in embodiments in which the at least one cleaning nozzle is configured for providing a jet of cleaning liquid into less than 100 % of the space between adjacent wafers at the same time, the cleaning nozzle may be pivotable for providing leaning liquid into 100 % of the space between adjacent wafers. Particularly, the at least one cleaning nozzle may be configured to be pivotable relative to the wafers over time such that at least 95%, particularly 100%, of the space between adjacent wafers can be subjected to cleaning liquid. Accordingly, embodiments of the wafer cleaning system as described herein provide an effective system with minimum hardware for in-situ cleaning of wafers in the wire saw.

[00227] According to embodiments described herein, the cleaning liquid is spread on the sliced ingot, e.g. the wafers, while the sliced ingot is extracted from the wire web 111. The extraction may be performed manually or automatically, for example by means of the ingot feeding system as described herein. Accordingly, the cleaning liquid can penetrate between the individual wafers, i.e. into the space between adjacent wafers.

[00228] According to embodiments of the wafer cleaning system which can be combined with other embodiments described herein, the cleaning liquid may be provided into a space between adjacent wafers from at least one side of the wafers for 8 to 20 min, particularly for 10 to 15 min. Additionally or alternatively, the cleaning liquid may be provided into a space between adjacent wafers from at least one side of the wafers at an amount of 6 1/min up to 12 1/min. Further, the cleaning liquid may be water, particularly deionized water, with a temperature of below 50° C (degree Celsius).

[00229] Further according to embodiments described herein, during extraction of the sliced ingot from the wire web 111 the wire forming the wire web may be moved. Accordingly, the movement of the wire may help to remove kerf material from the space between adjacent wafers. Further, the movement of the wire during extraction of the sliced ingot from the wire web can be beneficial for penetration of cleaning liquid into the space between adjacent wafers. Particularly, as the sliced ingot is extracted from the wire web, the wires of the wire web move within the space between adjacent wafers, which may be beneficial for the cleaning of the wafers.

[00230] Further, according to embodiments which may be combined with other embodiments described herein, the wire may be moved back and forth during ingot extraction from the wire web, which may further improve the cleaning efficiency.

[00231] According to embodiments which can be combined with other embodiments herein, the plurality of cleaning nozzles are movable relative to the wire web 111. In particular, the cleaning nozzles may be coupled to a kinematic mechanism structure, for example of an ingot feeding system 300 according to embodiments described herein. As exemplarily shown in Fig. 25A, the cleaning nozzles may be coupled to a support table 312 of the ingot feeding system as described herein.

[00232] According to embodiments which can be combined with other embodiments herein, the plurality of cleaning nozzles includes at least one first cleaning nozzle arranged for providing the cleaning liquid into the space between adjacent wafers from a first side, and at least one second cleaning nozzle arranged for providing the cleaning liquid into the space between adjacent wafers from a second side which is opposite to the first side. As exemplarily shown in Fig. 25 A, the cleaning nozzles may be directed towards a center of the wire web.

[00233] In particular, according to embodiments which can be combined with other embodiments described herein, the wafer cleaning system may include at least one first cleaning nozzle 541 configured and arranged for providing a cleaning liquid into the space between adjacent wafers from a first side 600 A of the wafers. Further, according to embodiments which can be combined with other embodiments described herein, the wafer cleaning system may include at least one second cleaning nozzle 542 configured and arranged for providing a cleaning liquid into the space between adjacent wafers from a second side 600B of the wafers. As exemplarily shown in Fig. 25 A, the first side 600A of the wafers and the second side 600B of the wafers may face outwards in opposing directions. In particular, the first side 600A of the wafers and the second side 600B of the wafers may be parallel to each other. As exemplarily shown in Fig. 25 A, the at least one first cleaning nozzle 541 and the at least one second cleaning nozzle 542 may be arranged mirror symmetrically for providing a cleaning liquid 544 into a space between adjacent wafers from opposite sides.

[00234] According to embodiments which can be combined with other embodiments described herein, at least one of the plurality of cleaning nozzles may be rotatable for directing the cleaning liquid to the wafers cut from the ingot under various angles during cleaning of the wafers after the cut.

[00235] According to embodiments of the wafer cleaning system which can be combined with other embodiments described herein, the at least one cleaning nozzle is directed towards the at least one side of the wafers with an inclination angle beta (β), as exemplarily shown in Fig. 25A. The inclination angle beta (β) of the at least one cleaning nozzle relative to the at least one side can be from beta = 10° to beta = 90°, particularly from beta = 15° to beta = 80°, more particularly from beta = 15° to beta = 70°. In particular, the inclination angle beta (β) of the at least one cleaning nozzle relative to the at least one side may be beta = 60°. Further, the inclination angle beta (β) may be adapted according to the nozzle position, size of the ingot to be sawed etc.

[00236] According to embodiments of the wafer cleaning system which can be combined with other embodiments described herein, the inclination angle beta (β) of the at least one cleaning nozzle may be adjustable. For example, the inclination angle beta (β) of the at least one cleaning nozzle may be adjustable in dependence of a distance between the support table 312 and the wire web 111. For example, as the distance of the support table relative to the wire web increases (e.g. during extraction of the cut ingot from the wire web) the inclination angle beta (β) of the at least one cleaning nozzle relative to the at least one side of the wafers may be decreased. For example, the inclination angle beta (β) of the at least one cleaning nozzle relative to the at least one side of the wafers may be decreased by means of an actuator configured for adjusting the inclination angle beta (β) of the at least one cleaning nozzle, e.g. by rotation of the at least one cleaning nozzle.

[00237] According to embodiments which can be combined with other embodiments described herein, the wafer cleaning system may include a collector tank 570 for collecting and/or filtering the cleaning liquid. Further, the collector tank may be configured for collecting broken wafers. In particular, the collector tank may protect the lower wire web from broken wafers, e.g. broken silicon wafers, which could damage the wire of the wire web and/or the wire guides. As exemplarily shown in Fig. 25 A, the collector tank 570 may be arranged between the first wire guide 112 and the second wire guide 114.

[00238] Accordingly, the removed kerf material may fall down into the collector tank. The collector tank may be configured for collecting the cleaning liquid including waste kerf material. Further, the collector tank may collect eventually broken wafers. Accordingly, the collector tank may prevent that broken wafers or other wastes can fall down on the lower wire web. The collector tank may collect all these items in order to remove them from the wire saw.

[00239] Fig. 25B shows a schematic perspective view of a collector tank 570 for the wafer cleaning system according to embodiments described herein. The collector tank 570 may include a cleaning flush 571 for providing cleaning liquid into the collector tank in order to flush waste material, for example broken wafers, out of the collector tank into a separate waste container.

[00240] According to embodiments which can be combined with other embodiments described herein, the collector tank may include a structured bottom 572 for preventing waste from sticking to the bottom. Additionally or alternatively, the collector tank may include one or more of a low friction coating, a Teflon coating, a structured Teflon coating and an anti- adhesive coating for prevention of waste, e.g. pieces of broken wafers, sticking to walls of the collector tank. Further, as exemplarily shown in Fig. 25B the bottom of the collector tank may be inclined from the cleaning flush side to an opposing cleaning liquid exit side 573. Accordingly, embodiments of the collector tank as described herein provide for smooth flushing. In other words, embodiments of the collector tank may effectively prevent clogging.

[00241] Embodiments of the wafer cleaning system as described herein are suitable for carrying out a method for cleaning wafers as described in the following.

[00242] According to embodiments of the method for cleaning wafers, the method includes providing a cleaning liquid into a space between adjacent wafers from at least one side of the wafers, as exemplary shown in Fig. 25A. Additionally, the method for cleaning wafers may include moving the wafers relative to the wire web. Particularly, moving the wafers relative to the wire web may include extracting the wafers from the wire web, while providing the cleaning liquid into the space between adjacent wafers. Accordingly, the cleaning efficiency may further be improved. Particularly, moving the wafers relative to the wire web may include dragging the cleaning liquid along the surface of the wafers by the wire of the wire web. For example, dragging the cleaning liquid along the surface of the wafers by the wire of the wire web may be performed by moving the wire relative to the surface of the wafers and vice versa. Particularly, when the wafers are extracted from the wire web, the wire of the wire web between adjacent wafers may help to drag the cleaning liquid along the surface of the wafers. Additionally or alternatively, the wire of the wire web may be moved relative to the wafers, while providing the cleaning liquid into the space between adjacent wafers. For example, the wire of the wire web may be moved back and forth during ingot extraction from the wire web while providing the cleaning liquid into the space between adjacent wafers. [00243] According to embodiments of the method for cleaning wafers as described herein, the cleaning liquid may be spread on the sliced ingot, in particular into the space between adjacent wafers during extraction of the sliced ingot is from the wire web. The extraction may be performed manually or automatically, for example by means of an ingot feeding system as described herein. Accordingly, the cleaning liquid can penetrate into the space between adjacent wafers to remnants of slurry and/or abraded material from the wafer surfaces.

[00244] Further, according to embodiments which may be combined with other embodiments described herein, moving the wafers relative to the wire web may include an alternating movement, particularly a rocking movement, of the wafers relative to the wire web. For example, the alternating movement of the wafers relative to the wire web may be performed by an ingot feeding system according to embodiments described herein. Accordingly, the cleaning efficiency may further be improved.

[00245] According to embodiments, which may be combined with other embodiments described herein, the method for cleaning wafers may include moving the wire web relative to the wafers, while providing the cleaning liquid into the space between adjacent wafers. For example, the wire of the wire web may be moved back and forth during ingot extraction from the wire web. Accordingly, the movement of the wire may help to clean the surface of the wafers, particularly remove kerf material from the space between adjacent wafers. Further, the movement of the wire during extraction of the sliced ingot from the wire web can be beneficial for penetration of cleaning liquid into the space between adjacent wafers. Particularly, as the sliced ingot is extracted from the wire web, the wires of the wire web may move within the space between adjacent wafers, which may be beneficial for cleaning the surface of the wafers. Further, a back and forth movement of the wire during ingot extraction from the wire web and application of the method for cleaning wafers according to embodiments described herein, may further improve the cleaning efficiency.

[00246] Accordingly, embodiments of the wafer cleaning system as well as embodiments of the method for cleaning wafers as described herein provide effective means for in-situ cleaning of wafers in a wire saw. Particularly, the wafer cleaning system and the method for cleaning wafers as described herein provides means for rinsing wafers with cleaning liquid to remove remnants of slurry and/or abraded material from the wafer surfaces in an effective manner. Further, embodiments of the wafer cleaning system as well as embodiments of the method for cleaning wafers as described herein may be beneficial for reducing the overall wafer manufacturing costs. In particular, by providing a wafer saw with a wafer cleaning system as described herein a separate pre-cleaning tool, which is conventionally used prior to the final wafer cleaning process, may not be necessary.

[00247] In the following, embodiments of the frame body for the wire saw system as described herein are described.

[00248] Fig. 26 shows a schematic cross-sectional view of the frame body 1122 of the lower cutting head 1100A of the wire saw system 1000 according to embodiments as described herein. The cross-sectional view of Fig. 26 is such that a portion of the frame body having two openings 117 is shown. The openings are provided for wire guides, in particular for wire guides according to embodiments described herein. At least two further openings are provided in the frame body (not shown in the cross-section of Fig. 40) for support at further axial positions of the wire guides. Accordingly, the frame body 1122 has at least four openings configured for receiving a set of wire guides, for example the first wire guide 112 and the second wire guide 114 as described herein. Two bearing box sleeves 132 are shown in Fig. 26. Corresponding to the openings, further bearing box sleeves are provided corresponding to further axial positions of the wire guide cylinders. Accordingly, at least four bearing box sleeves can be provided according to embodiments described herein.

[00249] According to some embodiments, at least four bearing box sleeves can be glued and/or press-fitted in a respective one of the at least four openings. The bearing box sleeves may have a ring-like form and can be provided for high precision mounting of the bearing boxes. Together with the mineral casting frame body the bearing box sleeves can be provided to obtain high precision regarding concentricity, parallelism and/or perpendicularity of the wire guide cylinders.

[00250] As exemplarily shown in Fig. 26, according to embodiments of the frame body described herein, a temperature control shield arrangement having one or more temperature control shields 120 is provided. The temperature control shield can cover inner portions of the frame body or can be cast into the frame body. As indicated by the dashed lines 128 in Fig. 26, according to some embodiments, which can be combined with other embodiments described herein, the temperature control shield arrangement can include one or more temperature control shields 120, a segmented temperature control shield or more than one segmented temperature control shields. The segmentation indicted by dashed lines 128 is for example provided in a manner that a portion above one of the axis 103 or below of one of the axis 103 can be heated or cooled independently and/or differently from other portions. Accordingly, potentially occurring temperature non-uniformities can be compensated for or reduced. Depending on possible non-uniformities that can be considered depending on the specific design of the cutting head and/or the application, different shapes and numbers of temperature control shields and/or different shapes of segments of a temperature control shield can be provided.

[00251] According to embodiments of the frame body which can be combined with other embodiments described herein, the frame body can be made of mineral casting. Further, the mineral casting frame body can be combined with the at least four bearing box sleeves and the one or more temperature control shields. Accordingly, a hybrid- structure of at least the mineral casting frame body, the one or more temperature control shields and the bearing box sleeves can be provided for the cutting head. For example, the at least four bearing box sleeves can be made of a material selected from the group consisting of: steel, cast iron, ceramic, and carbon fiber reinforced plastic.

[00252] According to further embodiments, which can be combined with other embodiments described herein, the one or more temperature control shields can be one or more heat shields, particularly one or more plates, which are cooled and heated. For example, the one or more plates can be fluid cooled, particularly water cooled. According to some implementations the one or more temperature control shields can be made of a material selected from the group consisting of: steel, stainless steel, copper, copper alloys, aluminum, aluminum alloys, plastics, and ceramics.

[00253] As described above, the bearing box sleeves can be made of steel or other materials described herein and can be glued into the mineral casting. For the mineral casting frame body, i.e. wherein the hybrid structure is formed, this can be conducted at high precision regarding concentricity, parallelism and/or perpendicularity. According to further implementations, the one or more heat shields can be made of water cooled/heated plates, e.g. stainless steel plates, which cover the inside of the process chamber (cutting head) or can be cast into the frame body. According to some additional or alternative modifications, conduits can be cast in the frame body.

[00254] Providing mineral casting for the frame body of the cutting head allows for enhanced casting flexibility (for example, more complex shapes, inner tubing, and piping). It is possible to implement cooling structures/devices. The cooling structures/devices can be provided close to the heat generating components. Accordingly, the temperature in the machine structure can be stabilized. The mineral casting production method further allows for higher accuracy and tighter tolerances as compared to regular (metallic) casting materials. For example, a higher positioning accuracy of the bearing box sleeves concentricity in the bearing box bores can be achieved. Further, the good dampening properties of the mineral casting are beneficial to reduce high frequency vibrations induced by the wire web. Accordingly, the noise level close to the machine can be reduced.

[00255] Figs. 27 and 28 are perspective views of the lower cutting head having a frame body 1122 according to embodiments described herein. Compared to Fig. 27, in Fig. 28 the wire guides, for example the first wire guide 112 and the second wire guide 114, and some of the corresponding components are shown. The frame body 1122 can have a front portion 1122A and a rear portion 1122B. As exemplarily shown in Fig. 27, the openings 117 are provided in the front portion and the rear portion. Further, the bearing box sleeves 130 can be provided in the openings 117, for example by gluing and/or press fitting. The rear portion 1122B and the front portion 1122A may be connected to a base portion 113. Further, the rear portion 1122B and the front portion 1122A can be connected by connecting portions 1144. The front portion, the rear portion, the base portion and the connecting portions are cast by mineral casting, i.e. are integrally formed. The connecting portions 1144 leave an opening, e.g. at the top, in order to feed the workpiece, e.g. an ingot, towards the cutting zone provided within the lower cutting head.

[00256] According to some embodiments of the frame body, which can be combined with other embodiments described herein, the frame body can have a plurality of openings 291A and cut-outs 291B. The cut outs can be provided for easier access to the processing area or for insertion of other components of the wire saw system as described herein. The openings 291 A can be provided for connecting the cutting head to other components of the wire saw system, e.g. by bolts, screws or other means and can be used to connect various components to the cutting head. For example, sensors as described in more detail below can be connected, components of a slurry delivering system (if not integrated in the casting) can be connected and/or an ingot feeding system can be connected as also described in more detail below.

[00257] According to some embodiments of the frame body, which can be combined with other embodiments described herein, the cutting head 1100 or the frame body 1122 can be equipped with temperature sensors: The temperature sensors may, for example, be provided at various positions of the cutting head or the frame body, respectively. The temperature sensor can measure the temperature at the various positions and can be connected via a controller to the temperature control shields. In Fig. 27 temperature control shields 120 and 220Aare shown. In Fig. 28 showing the frame body under a different viewing angle when compared to Fig. 27, temperature control shields 220A and 220B are shown. Further, one or more of the temperature sensor(s) can be adapted to control and stabilize the temperature of the frame body. Accordingly, overall temperature variations of the structural frame can be compensated for or reduced. For example, the temperature control and stabilization is done by varying the flow and temperature of the water to and from the temperature control shields, e.g. heat shields.

[00258] According to further embodiments of the frame body, which can be combined with other embodiments described herein, vibration sensors may be provided. Even though the damping properties of mineral casting are beneficial for the embodiments of the wire saw system as described herein, monitoring of system vibrations can be used to monitor the system condition and, e.g. to control the operation of the wire saw device.

[00259] Further, Fig. 28 shows the wire guides, for example a first wire guide 112 and a second wire guide 114, which are provided in the lower cutting head 1100A. As exemplarily shown in Fig. 28, inside the bearing box sleeves 130, the bearing boxes 230 can be provided. The bearing boxes support the wire guides and allow for rotation of the wire guides around the axes of the wire guides. Further, drives (e.g. a first motor 122 and a second motor 124) may rotate the wire guide cylinders.

[00260] According to some embodiments of the frame body, which can be combined with other embodiments described herein, the temperature control shields (120, 220A and 220B) can be provided inside the frame body 1122 or can be cast into the frame body 1122. [00261] According to embodiments of the frame body, which can be combined with other embodiments described herein, at least one temperature sensor for measuring the temperature of the frame body is provided. The at least one temperature sensor can be connected to a controller. The controller can control the one or more temperature control shields. Particularly, the controller may provide a closed loop control together with the at least one temperature sensor. The sensors 251, exemplarily shown in Fig 27, may be temperature sensors as shown. According to embodiments, the sensors as described herein can be cast into the frame body, as indicated by the dotted lines. Additionally or alternatively, one or more of the sensors can be provided at the surface of the frame body.

[00262] In Fig. 27 exemplarily one of the sensors 251 is connected to the controller 252. It is to be understood that all of the temperature sensors can be connected to a controller, wherein some or all sensors can also be connected to a common controller, e.g. in order to more easily correlate the temperature measurement results of several temperature sensors. The controller 252 can be part of the electrical control system 1300 of the wire saw system as described herein.

[00263] With exemplary reference to Fig 27, the controller 252 may control a valve 253 for controlling the flow of cooling fluid to the temperature control shield 220A. Accordingly, the at least one of the sensors 251, for example a temperature sensor, the controller 252, the valve 253 and at least one of the temperature control shields can form a closed loop. According to further embodiments, one or more valves can be controlled by the controller. According to some embodiments, which can be combined with other embodiments described herein, the controller can be configured to vary the flow and/or temperature of the fluid.

[00264] In light of the above, a method of operating a wire saw device can include: measuring the temperature of a region of a mineral casting frame body, particularly of a wire saw system according to embodiments described herein; and varying the flow and/or the temperature of a temperature control fluid in a temperature control shield provided in or at the frame body of the cutting head in dependence of the measured temperature. It is further possible that according to one optional modification, vibrations are measured and at least one operation condition is varied dependent on the measured vibrations.

[00265] Further, according to embodiments described herein mineral casting can be used for one or more structural parts of the wire saw system as described herein. For example, the upper cutting head can include a structural frame 305 made of mineral casting. As exemplarily shown in Fig. 31, the upper cutting head may include an ingot feeding system 300 according to embodiments described herein.

[00266] According to embodiments described herein, which can be combined with other embodiments described herein, the structural frame 305 of the upper cutting head can be mounted to the frame body 1122 of the lower cutting head, as exemplarily shown in Fig 31. Alternatively, the structural frame 305 of the upper cutting head and the frame body of the lower cutting head may be integrally formed. According to some embodiments, which can be combined with other embodiments described herein, the structural frame 305 of the upper cutting head can be made of mineral casting. Accordingly, the benefits of mineral casting with respect to precision, damping properties and/or flexible manufacturing can also be provided for the upper cutting head.

[00267] According to some embodiments, the structural frame of the upper cutting head may be made of cast iron. Further, the structural frame of the upper cutting head can be provided with integrated water cooling/heating circuits for temperature control and stabilization. The structural frame of the upper cutting head and/or the circuits and pipes can be coupled with the lower cutting head frame body frame and corresponding the circuits and pipes of the lower cutting head.

[00268] The temperature control and stabilization of the structural parts allow for avoiding thermal dilatation during the cut at various process steps with more or less heat generation. Furthermore, a temperature stabilized structure needs no warm-up time before a cut. Thus, the non-productive time of the wire saw device can be reduced to a minimum.

[00269] As described above, one of the positive effects of providing structural parts of the wire saw device by mineral casting is the improved damping properties of cast iron. Fig. 33 shows a first graph 901 for cast iron and a second graph 902 for mineral casting where vibration amplitude of a few micrometers are shown as a function time in order to illustrate the damping of the frame body. Both graphs show the same amplitude scale and the same time scale. It can be seen that the damping of the mineral casting curve, i.e. the second graph 902, results in a significantly faster reduction of the vibration amplitude than the damping of the cast iron curve, i.e. the first graph 901. The reduced vibration levels result in better precision of the cut and, thus, in an improved yield of the wire saw device because, e.g., the tolerances for the sawed wafers can be more easily achieved due to the reduced vibration.

[00270] According to embodiments described herein, one or more of the benefits of using mineral casting material can be provided as follows: the cutting process can be improved due to control of the vibration level in the machine structure and the wire web. This can be achieved by utilizing the dampening properties of the mineral casting in order to reduce the vibration level in the machine's structural parts, like the frame body and the frame of the feeding system and/or by utilizing vibration monitoring. For example the wire saw device can include vibration sensors in the machine frame. Fig. 29 shows a frame body 1122 in which a vibration sensor 1050 is shown. This sensor can be provided at the frame body 1122 or can be cast into the frame body 1122. According to some embodiments, which can be combined with other embodiments described herein, one or more vibration sensors configured to monitor the vibrations of the frame body can be provided.

[00271] Fig. 29 shows further elements that can be included in embodiments of the mineral casting frame body, which can be combined with other embodiments described herein. For example, various air ducts 1002 can be provided in the frame body. Additionally or alternatively, tubes 1006 for wire harnesses can be provided in the frame body. The wire harnesses can be used to connect sensors, valves (e.g. for the slurry delivery system), or other components to the controller, particularly the electrical control system 1300 of the wire saw system as described herein. Further, additionally or alternatively, water pipes 1004 can be provided for providing water to the temperature control shields. These water pipes can particularly guide water to regions close to the bearings, where access heat can be generated during operation of the wire saw device. According to some embodiments, which can be combined with other embodiments described herein, at least one element selected from the group consisting of: a plate, a fluid piping, an electrical connector, a wire harness tube, an air duct and a sensor is cast into the frame body.

[00272] Accordingly, embodiments as described herein provide for enhanced casting flexibility (for example, more complex shapes and inner tubing and/or piping) of mineral casting. Further, the temperature in the machine structure can be stabilized by implementing cooling structures and/or cooling devices close to heat generating components (e.g. the bearings), as exemplarily described above. [00273] Further, by employing a mineral casting production method with higher accuracy and tighter tolerances as compared to regular (metallic) casting material, a higher positioning accuracy of the bearing box sleeves concentricity can be achieved.

[00274] In the following embodiments of a method for manufacturing the frame body of the cutting head of the wire saw system as described herein is described. The method of manufacturing the frame body of the cutting head may include: providing a temperature control shield arrangement in a mold; casting the frame body of the cutting head having at least four openings in the mold, wherein the casting is conducted with a mineral filler and a binder. Further, the method of manufacturing the frame body of the cutting head may include providing at least four bearing box sleeves in the respective four openings. The bearing box sleeves can be glued, press-fitted, or glued and press-fitted. According to further optional implementations, at least one element selected from the group consisting of: a plate, a fluid piping, an electrical connector, and a sensor, can be arranged in the mold before casting the frame body.

[00275] Embodiments described herein relate to structural parts of a wire saw device manufactured by mineral casting. Particularly, the frame body of the cutting head, the frame of the ingot feeding system or the frame body of an integral component of the cutting head can be provided by mineral casting. In particular, one or more structural frames can be provided by mineral casting according to embodiments described herein. Accordingly, a hybrid- structure can be provided in combination with one or more temperature control shields and bearing box sleeves.

[00276] According to embodiments which can be combined with other embodiments described herein a wire saw system 1000 is provided. The wire saw system includes a cutting head 1100 having a frame body. The frame body includes at least four openings configured for receiving a set of wire guides, particularly a first wire guide 112 and a second wire guide 114. Further, the frame body includes at least four bearing box sleeves and a temperature control shield arrangement having one or more temperature control shields. The frame body is made of mineral casting and can be combined with the at least four bearing box sleeves and the one or more temperature control shields. Each one of the at least four bearing box sleeves is provided in a respective one of the at least four openings. [00277] According to embodiments of the wire saw system, which can be combined with other embodiments described herein, the at least four bearing box sleeves are made of a material selected from the group consisting of: steel, cast iron, ceramic, and carbon fiber reinforced plastic.

[00278] According to embodiments of the wire saw system, which can be combined with other embodiments described herein, each one of the at least four bearing box sleeves is glued and/or press-fitted in a respective one of the at least four openings.

[00279] According to embodiments of the wire saw system, which can be combined with other embodiments described herein, the one or more temperature control shields are one or more heat shields, particularly one or more plates, which are cooled and/or heated.

[00280] According to embodiments of the wire saw system, which can be combined with other embodiments described herein, the one or more plates are fluid cooled, particularly water cooled.

[00281] According to embodiments of the wire saw system, which can be combined with other embodiments described herein, the one or more temperature control shields are made of a material selected from the group consisting of: steel, stainless steel, copper, copper alloys, aluminum, aluminum alloys, plastics, and ceramics.

[00282] According to embodiments of the wire saw system, which can be combined with other embodiments described herein, wherein the one or more temperature control shields cover inner portions of the frame body or are cast into the frame body.

[00283] According to embodiments of the wire saw system, which can be combined with other embodiments described herein, the wire saw system further includes at least one temperature sensor for measuring the temperature of the frame body. The at least one temperature sensor is connected to a controller. The controller controls the one or more temperature control shields. Particularly the controller provides a closed loop control together with the at least one temperature sensor.

[00284] According to embodiments of the wire saw system, which can be combined with other embodiments described herein, the controller is configured to vary the flow and/or temperature of the fluid. [00285] According to embodiments of the wire saw system, which can be combined with other embodiments described herein, further including an ingot feeding system having a structural body, wherein the structural body of the ingot feeding system is made of mineral casting, steel or cast iron.

[00286] According to embodiments of the wire saw system, which can be combined with other embodiments described herein, one or more vibration sensors can be configured to monitor the vibrations of the frame body, particularly in the bearing box sleeve area.

[00287] According to embodiments of the wire saw system, which can be combined with other embodiments described herein, at least one element selected from the group consisting of: a plate, a fluid piping, an electrical connector, a wire harness tube, and air duct, and a sensor is cast into the frame body.

[00288] According to embodiments described herein, a method of manufacturing a wire saw system is provided. The device method of manufacturing a wire saw system includes: providing a temperature control shield arrangement in a mold; casting a frame body of a cutting head having and at least four openings in the mold, wherein the casting material is composed of a mineral filler and a binder; and gluing and/or press-fitting at least four bearing box sleeves in the respective for openings.

[00289] According to embodiments of the method of manufacturing a wire saw system, which can be combined with other embodiments described herein, the method further includes providing at least one element selected from the group consisting of: a plate, a fluid piping, an electrical connector, and a sensor, in the mold before casting the frame body.

[00290] According to embodiments of the method of manufacturing a wire saw system, which can be combined with other embodiments described herein, the method further includes mounting bearing boxes for wire guide cylinders and wire guide cylinders to be supported by the bearing box sleeves.

[00291] In the following, embodiments of an ingot feeding system 300 for the wire saw system 1000 as described herein are described.

[00292] In the present disclosure, an "ingot feeding system", or simply "feeding system", may be understood as a system controlling the position of a piece to be sawed, e.g. an ingot. In particular, the controlling of the position of a piece to be sawed may be done by a controller of the ingot feeding system. The controller of the ingot feeding system can be part of the electrical control system 1300 of the wire saw system as described herein.

[00293] In Fig. 31 a schematic perspective view of an excerpt of the wire saw system is shown, in which an ingot feeding system 300 is mounted to the structural frame 305 of the upper cutting head 1100B.

[00294] As exemplarily shown in Fig. 31 an ingot feeding system 300 for a wire saw system 1000 according to embodiments described herein includes a kinematic mechanism structure 350. Further, the ingot feeding system 300 includes at least one actuator 352 for moving at least one part of the kinematic mechanism structure 350, a support table 312 for coupling an ingot 600 to the kinematic mechanism structure 350.

[00295] According to further embodiments which can be combined with other embodiments described herein the ingot feeding system 300 may include at least one sensor for measuring a force acting on the kinematic mechanism structure 350. For example, the at least one sensor can be a strain gauge sensor. Strain gauge sensors can be attached to the kinematic mechanism structure in a simple manner and at substantially any site of interest.

[00296] In the present disclosure the term "kinematic mechanism structure" refers to any means configured for providing a rotational and/or transversal movement. Particularly, a "kinematic mechanism structure" as described herein relates to an arrangement of at least two elements, particularly connecting at least two bodies, wherein the at least two elements are connected to each other such that at least one of the at least two elements is movable relative to the other element or elements of the at least two elements of the arrangement, e.g. by rotation around an articulation and/or translation along an axis.

[00297] According to embodiments which can be combined with other embodiments described herein, the ingot feeding system 300 can include a parallel kinematic mechanism structure having for example three arms and at least one actuator 352, as exemplarily shown in Figs. 31 and 32.

[00298] In the present disclosure the term "parallel kinematic mechanism structure" may be understood as a "kinematic mechanism structure" wherein at least one of the at least two bodies is connected to the "parallel kinematic mechanism structure" at two or more different locations. Accordingly, a movement of one of the elements of the parallel kinematic mechanism structure may translate into a movement of at least a part of the kinematic mechanism structure (e.g. another element of the kinematic mechanism structure).

[00299] According to embodiments of the ingot feeding system, which can be combined with other embodiments described herein, the ingot feeding system may be configured for rotating the ingot around an axis of rotation which is perpendicular to the cutting direction. The ingot feeding system may be configured such that during cutting of the ingot, the location of the axis of ration can be controlled within the distance D between the axis of rotation and the wire web, wherein the distance D is smaller than D = + 10 mm, particularly smaller than D = + 5 mm, particularly smaller than D = + 2.5 mm.

[00300] According to embodiments of the ingot feeding system which can be combined with other embodiments described herein, the ingot feeding system may be configured such that during cutting of the ingot, the location of the axis of ration can be located on a curve of contact of the ingot with the wire of the wire web within a tolerance T of T = + 10 mm, particularly T = + 5 mm, particularly T = + 2.5 mm. In the present disclosure, the term "curve of contact" may be understood as the imaginary curve along which the wire touches the ingot during sawing the ingot. For example, the term "curve of contact" may be understood as a straight line, a bow, or any other curve which the wire may form in the region of the wire in which the wire touches the ingot during sawing of the ingot.

[00301] According to embodiments of the ingot feeding system which can be combined with other embodiments described herein, the kinematic mechanism structure may be controlled based on a measurement result of the wire bow measurement system as described herein, particularly in a closed loop control. For example, the kinematic mechanism structure may be controlled based on a measurement result of the wire bow measurement system such that the distance D between the axis of rotation and the wire web may remain smaller than D = + 10 mm, particularly smaller than D = + 5 mm, particularly smaller than D = + 2.5 mm, for example as described in connection with Fig. 3A. Further, the kinematic mechanism structure may be controlled based on a measurement result of the wire bow measurement system such that the axis of rotation of the ingot may remain on a curve of contact of the wire of the wire web with the ingot within a tolerance T of T = + 10 mm, particularly within T = + 5 mm, particularly within T = + 2.5 mm.

[00302] Accordingly, embodiments of the ingot feeding system as described herein provide for adapting and optimizing the cutting condition of the ingot throughout the sawing process. Particularly, embodiments of the ingot feeding system as described herein provide for holding the cutting condition substantially constant throughout the sawing process of the ingot.

[00303] As exemplarily shown in Fig. 31, according to embodiments of the ingot feeding system which can be combined with other embodiments described herein, the at least two arms 343 can be rotatably connected to the support table 312, e.g. via a hinged joint. Further, the arms may be rotatably connected to the at least one actuator 352, e.g. via a hinged joint. A workpiece, e.g. the ingot 600, can be mounted via a mounting plate 376 to the support table 312.

[00304] According to embodiments of the ingot feeding system which can be combined with other embodiments described herein, the actuators can be configured to realize a movement along a translational axis, particularly a vertical axis. Further, the actuators may be guided via guide rails 341 provided on the structural frame 305 of the upper cutting head, as exemplarily shown in Fig. 31. The guide rails may be arranged in the direction of the cutting direction, particularly in a vertical direction. Further, the actuators may be configured such that each of the actuators can move separately. Accordingly, by moving at least one actuator 352, the at least two arms 343, the support table 312 and accordingly the ingot 600 connected to the support table can be moved.

[00305] For example, when all actuators are moving in the same direction with the same speed the ingot is urged downwards in the representation of Fig. 31 and 32, in particular towards the wire web 111. In the case that at least one of the actuators is moving at a different speed and/ or in a different direction compared to the other actuators, a rotational movement of the ingot can be realized. Accordingly, a relative motion between the actuators can be used to move the ingot 600 in a cutting plane, for example in the z-x-plane of Fig. 32. Additionally or alternatively a tilt of the ingot 600, e.g. with an angle relative to the wire web 111 may be provided. [00306] According to embodiments of the present disclosure, the term "cutting plane" may include the cutting direction. Accordingly, the orientation of the cutting plane remains constant throughout the complete cutting process. Particularly, the orientation of the cutting plane may correspond to the orientation of the wires of the wire saw.

[00307] Further, in the present disclosure the term "cutting direction" may be understood as the direction in which the cut advances during the cutting process. Particularly, the cutting direction can be a vertical direction.

[00308] Fig 32 shows a perspective view of an ingot feeding system according to embodiments described herein. As shown in Fig. 32, according to embodiments described herein, the ingot feeding system 300 may include a parallel kinematic mechanism structure 350A, at least two arms 343 having first ends and second ends, and at least one actuator 352. With exemplary reference to 32, for example two arms of the three arms shown in Fig. 32 can be configured as a frame structure. As exemplarily shown in Fig. 32, according to embodiments of the ingot feeding system as described herein, one of the at least two arms 343 may be an expanding/contracting arm. As exemplarily shown in Fig. 32, the first ends of the at least two arms 343 are rotatably connected to the support table 312, e.g. via a hinged joint, whereas the second ends of the at least two arms 343 are rotatably connected to at least one slide 344, particularly via a hinged joint. Further, as exemplarily shown in Fig. 32, at least one sensor for measuring force acting on the kinematic mechanism structure 350 may be provided.

[00309] Further, Fig. 32 shows a perspective view of an ingot 600 that is partially sawed due to a movement of the ingot feeding system 300 urging the ingot 600 against the wire web 111 disposed in the cutting zone region of the wire saw system as described herein. As described above, the pitch between adjacent wires of the wire web may be defined by engraved grooves on the periphery of the wire guides which determines the thickness of the sawed slices 331. As exemplarily shown in Fig. 32, the sawed slices can be separated from each other by slots or sawing gaps 332.

[00310] Embodiments of the ingot feeding system including at least one sensor for measuring force acting on the kinematic mechanism structure provide for measuring the force acting on the kinematic mechanism structure. Accordingly, information about the force transmitted to the ingot via the wire web during the cutting process can be obtained. For a better understanding, the acting on the kinematic mechanism structure, particularly on the arms, can are illustrated by Fl, F2, F3 and F4 in Fig 31.

[00311] This information may further be employed for force feedback control of cutting process parameters during cutting to ensure constant and reproducible cutting results. For example, a force based control algorithm enabling a closed loop cutting process control can be used. Accordingly, the cutting force during the complete cutting process can be controlled according to a predefined force profile. The force profile can be a function of the position of the ingot and/or of the time progress of the cutting process. For example, the cutting force can be controlled such that it remains substantially constant throughout the whole cutting process. Alternatively, the cutting process may be controlled such that for example the cutting force increases or decreases as the ingot advances through the wires of the wire web.

[00312] Further, according to embodiments described herein the cutting force can be controlled as a function of at least one cutting process parameter such as an ingot feeding speed, a wire speed, a wire tension, a wire temperature, a coolant supply rate, and a coolant temperature. Additionally or alternatively, the measured force acting on the ingot can also be used as input for the wire management system according to embodiments described herein, for example, for controlling the wire tension which is described in more detail in connection with Figs. 34, 51 and 52.

[00313] According to embodiments, the feeding system further includes a controller for controlling a cutting process parameter by use of a force feedback control and/or by use of a measurement result of the wire monitoring system according to embodiments described herein. The controller for controlling the cutting process parameter can be part of the electrical control system 1300 of the wire saw system as described herein. The controller may be used for monitoring the force acting on the kinematic mechanism structure. The sensors for measuring a force acting on the kinematic mechanism structure of the ingot feeding system can be connected to the controller. The controller may be configured for processing the signal generated by the sensors (401, 402, 403, 404, and 405). Further, the controller may compute the respective force measurement data from the signal generated by the sensors (401, 402, 403, 404, and 405). Further, the controller may be capable of performing real-time online monitoring of a force acting on the kinematic mechanism structure and real-time online monitoring of a force acting on the ingot during the sawing process. [00314] According to embodiments which can be combined with other embodiments described herein, a control algorithm is employed to control cutting process parameters based on the force measurement data and/or the wire bow measurement data. Accordingly, embodiments of the ingot feeding system are suitable for closed loop force feed-back control of cutting process parameters and/or closed loop wire bow feedback control of cutting process parameters. Cutting process parameters as described herein may include an ingot position, an ingot orientation, an ingot feeding speed, a wire speed, a wire temperature, a wire tension, a coolant supply rate, a coolant temperature, a rocking angle, a rocking trajectory, a rocking frequency, a rocking speed and the like.

[00315] According to embodiments described herein, a force based and/or wire bow based control algorithm enabling a closed loop cutting process control may be used. Accordingly, according to the embodiments of the ingot feeding system as described herein the cutting force during the complete cutting process can be controlled according to a selectable force profile as a function of a position of the ingot and/or time progress of the cutting process.

[00316] According to embodiments which can be combined with other embodiments described herein, the cutting process parameter controlled by the controller includes a position of the ingot and/ or an orientation of an ingot and/or an ingot feeding speed and/or a wire speed and/or a wire temperature and/or a wire tension and/or a coolant supply and/or a coolant temperature and/or a rocking angle and/or a rocking trajectory and/or a rocking frequency and/or and a rocking speed.

[00317] Alternatively, according to embodiments, data acquired by a bow measurement system can be used for controlling the cutting force during cutting. Particularly, the bow measurement system is configured to measure and monitor a bow of a wire portion within the piece to be sawed. According to embodiments, the bow measurement system is connected to the controller for controlling a cutting process parameter. Particularly, the controller employs the bow measurement data for controlling the cutting force, which can be controlled as a function of at least one cutting process parameter such as an ingot position, an ingot orientation, an ingot feeding speed, a wire speed, a wire temperature, a wire tension, a coolant supply rate, a coolant temperature, a rocking angle, a rocking trajectory, a rocking frequency, and a rocking speed. [00318] According to embodiments of the ingot feeding system as described herein, the at least one actuator 352 is a motor for controlling the ingot position via the kinematic mechanism structure 350. The actuator may be operated by a source of energy, for example in the form of an electric current, hydraulic fluid pressure or pneumatic pressure converting the energy into motion. According to some embodiments, the at least one actuator of the ingot feeding system can be an electrical motor, a linear motor, a pneumatic actuator, a hydraulic actuator or a piezoelectric actuator. Accordingly, the actuators can be used to realize a motion of the kinematic mechanism structure, in particular a motion within the kinematic mechanism structure (e.g. by a linear motion of at least one element of the kinematic mechanism structure).

[00319] According to some embodiments, conversion from a rotational motion of a motor into a linear motion can be made via a screw principle or a wheel and axle principle. For example, screw actuators operating on the screw principle include screw jack, ball screw and roller screw actuators. By rotating an actuator's nut, a screw shaft moves along a line. Correspondingly, by moving the screw shaft, the nut rotates. Actuators operating on the wheel and axle principle include a hoist, winch, rack and pinion, chain drive, belt drive, rigid chain and rigid belt. By rotating a wheel/axle (e.g. drum, gear, pulley or shaft) a linear member (e.g. cable, rack, chain or belt) moves.

[00320] According to some embodiments of the ingot feeding system as described herein, the at least one sensor can be attached to the kinematic mechanism structure by a suitable adhesive, for example cyanoacrylate. During wafer cutting, force acting on the ingot is transmitted into the kinematic mechanism structure causing strain within the kinematic mechanism structure. This strain can be measured by the sensors, particularly strain gauge sensors. In order to detect and measure the force acting on the ingot with a high sensitivity, the sensors can be arranged at positions of the kinematic mechanism structure at which the highest deformation resulting from the strain occurs. For example, the highest deformation can take place at a central location on the surfaces of the arms. Further, the sensors may be oriented such that their direction of highest measurement sensitivity corresponds to the direction of the force transmitted into the kinematic mechanism structure, for example a longitudinal direction of an element of the kinematic mechanism structure. [00321] According to embodiments of the ingot feeding system, which can be combined with other embodiments described herein, the at least one sensor may be arranged on the at least one actuator. The at least one actuator can be linear actuator, for example a linear actuator based on the screw principle as outlined above. According to embodiments, the at least one sensor can be arranged around a nut of the linear actuator based on the screw principle. Particularly, the at least one sensor arranged around the screw shaft may be a ring- shaped sensor.

[00322] During cutting, the wire is subjected to wear. Accordingly, the wire may reduce in diameter during the sawing process compared to the initial diameter of the wire before the sawing process. The wear of the wire may be process dependent. For example, the higher the cutting rate, the higher the resulting temperature, and the higher the wire wear. Additionally, the wire is heated inside the ingots where the abrasion takes place during sawing, that is, particularly inside the wafers. Outside the ingot, the wire cools down by exchanging heat with its surroundings such as the slurry, air, and the guide cylinders or further wire guides. Consequently, as the diameter of the cutting wire and thus its mechanical properties change during the cutting process as a function of time and temperature, the cutting force acting on the ingot by the wire may change. Accordingly, the abrasion property of the wire may change during the cutting process which may result in undesirable inhomogeneous cutting surfaces of the wafers cut from the ingot.

[00323] By providing an ingot feeding system according to embodiments described herein with which the force acting on the ingot during the cutting process can be measured the quality of the wafers can be improved. Further, with embodiments of the ingot feeding system as described herein, information about the force transmitted to the ingot via the wire web during the cutting process can be obtained by measuring the force acting on the kinematic mechanism structure. This information may be employed for force feedback control of cutting process parameters during cutting to ensure constant and reproducible cutting results.

[00324] According to alternative embodiments, the ingot feeding system can include a straight ingot feeding. In Fig. 33 a schematic side view of an exemplary embodiment of an ingot feeding system including a linear kinematic mechanism structure 350B is illustrated. As exemplarily shown in Fig. 33, according to embodiments a motor 319 acting as actuator for performing a linear movement via the kinematic mechanism structure 350 can be provided. Further, multiple sensors 401, 402. 403, 404, 405 for measuring force acting on the kinematic mechanism structure are provided.

[00325] As exemplarily shown in Fig. 33, the linear kinematic mechanism structure 350B can be based on a screw principle. In particular the motor 319 can be arranged such that a screw shaft of the kinematic mechanism structure can be driven. As exemplarily shown in Fig. 33 the screw shaft may engage with a corresponding nut which is connected to a further element 351 of the kinematic mechanism structure, wherein the further element is arranged such that it can move in a linear direction. With exemplary reference to Fig. 33, the further element 351 can be configured as an elbow element. The elbow element can be connected to the frame structure of the upper cutting head. Accordingly, a translational movement, particularly in the cutting direction can be realized. Further, between the elbow element and the frame structure of the upper cutting head a slide mechanism may be provided.

[00326] For example, guide rails 341 may be attached to the structural frame 305 of the upper cutting head. Further, corresponding slide elements (not shown) may be attached to the kinematic mechanism structure, e.g. to the elbow element. Accordingly, a guided movement of the kinematic mechanism structure along the axis of the cutting direction may be realized. According to some embodiments, at least two guide rails and at least two slide elements, particularly four slide elements, may be implemented. As exemplarily shown in Fig. 33, the guide rails can be arranged parallel in cutting direction. Further, the screw shaft and the slide elements may be provided with sensors 401, 402, 403, 404, 405 for measuring a force, in particular the force components of a force, acting on the kinematic mechanism structure.

[00327] With exemplary reference to Fig 33, according to embodiments, a part of the sensors are provided on the slide elements and can be arranged and configured for measuring a horizontal force component, as exemplarily illustrated by Fl and F2, of the force acting on the kinematic mechanism structure during cutting. Further, at least one sensor, for example the sensor 405 illustrated in Fig. 33, can be arranged and configured for measuring a vertical force component of the force, exemplarily illustrated by F3, acting on the kinematic mechanism structure during cutting. According to some embodiments, as exemplarily shown in Fig. 33, the sensor for measuring a vertical force is provided on the screw shaft. Although, not specifically shown in Fig. 33, sensors may be arranged on other positions of the kinematic mechanism structure which are suitable for measuring vertical and horizontal force components of force acting on the kinematic mechanism structure during cutting. For example, force sensors may be provided on the support table 312 and/ or the mounting plate 376 and/ or the guide rails 341.

[00328] Further according to embodiments described herein, a method for feeding an ingot during cutting is provided. The method for feeding an ingot during cutting may include: feeding an ingot to a wire saw by use of a kinematic mechanism structure; monitoring a force acting on the ingot during cutting by measuring the force in the kinematic mechanism structure and/or monitoring a wire bow by the wire bow monitoring system as described herein, and controlling at least one cutting process parameter based on the monitored force and/or the measured wire bow. In particular, an ingot feeding system according to embodiments described herein is used for carrying out the method for feeding an ingot during cutting. According to embodiments, feeding an ingot to a wire saw may include urging the ingot towards the wire web, particularly by means of the ingot feeding system as described herein.

[00329] According to embodiments of the method for feeding an ingot during cutting, in particular wafer cutting, feeding the ingot to the wire web of the wire saw includes an alternating movement of the ingot, in particular a rocking movement.

[00330] According to embodiments of the method, which can be combined with other embodiments described herein, the rocking movement of the ingot may include a rotational movement with a fixed radius, for example a rotational movement along a trajectory of an arc of a circle which is perpendicular to the cutting direction. Additionally or alternatively, the rocking movement of the ingot may include a rotational movement with a variable radius, for example one or more of an ellipsoidal movement, a parabolic movement, and an hyperbolic movement along a trajectory which is perpendicular to the cutting direction. According to embodiments described herein, the alternating movements, in particular the rocking movement is a back and forth movement along a trajectory. Further, the rocking movement may include one or more of a rocking angle, a rocking trajectory, a rocking frequency and a rocking speed. Further, according to embodiments of the method for feeding an ingot during cutting, monitoring a force acting on the ingot may include measuring the force based on a signal generated by at least one sensor or by at least one actuator. [00331] Additionally or alternatively, the method for feeding an ingot during cutting may include monitoring a wire bow based on a signal generated by the wire bow monitoring system according to embodiments described herein. The generated signal can be transmitted to a controller for controlling a cutting process parameter by use of a force feedback control and/or wire bow feedback control. The transmitted signal can be processed by the controller for computing the respective force measurement data. In particular, the controller may perform real-time online monitoring of force acting on the kinematic mechanism structure, for example by force measurement or wire bow measurement. Accordingly, real-time online monitoring of force acting on the ingot during the sawing process is performed by the controller. The controller for controlling a cutting process parameter can be part of the electrical control system 1300 of the wire saw system 1000 as described herein.

[00332] According to embodiments of the method for feeding an ingot during cutting, the controlling of at least one cutting process parameter includes a closed loop control. The at least one cutting process parameter may include an ingot position and/or an ingot orientation and/or an ingot feeding speed and/or a wire speed and/or a wire temperature and/or a wire tension and/or a coolant supply rate and/or a coolant temperature and/or a rocking angle, and/or a rocking trajectory and/or a rocking frequency and/or a rocking speed.

[00333] According to embodiments described herein, an ingot feeding system 300 for a wire saw system 1000 as described herein is provided. The ingot feeding system 300 includes a kinematic mechanism structure 350; at least one actuator 352 for moving at least one part of the kinematic mechanism structure 350; a support table 312 for coupling an ingot 600 to the kinematic mechanism structure 350.

[00334] According to embodiments of the ingot feeding system 300, which can be combined with other embodiments described herein the ingot feeding system may include at least one sensor for measuring a force acting on the kinematic mechanism structure 350.

[00335] According to embodiments of the ingot feeding system 300, which can be combined with other embodiments described herein, wherein the feeding system further includes a controller for at least one of controlling a cutting process parameter by use of a force feedback control and/or wire bow feedback control, monitoring the force acting on the kinematic mechanism structure 350, and monitoring the wire bow. [00336] According to embodiments of the ingot feeding system 300, which can be combined with other embodiments described herein, the cutting process parameter includes at least one of a position of the ingot 600, an ingot feeding speed, a wire speed, a coolant supply and a coolant temperature.

[00337] According to embodiments of the ingot feeding system 300, which can be combined with other embodiments described herein, wherein the at least one sensor is a force sensor, in particular a strain gauge sensor.

[00338] According to embodiments of the ingot feeding system 300, which can be combined with other embodiments described herein, the kinematic mechanism structure 350 is a parallel kinematic mechanism structure, comprising at least two arms 343 wherein each arm includes a first end and a second end.

[00339] According to embodiments of the ingot feeding system 300, which can be combined with other embodiments described herein, the kinematic mechanism structure 350 is configured to enable at least one of a translational movement of the ingot 600 within a cutting plane, wherein the cutting plane includes a cutting direction, and a rotational movement around a rotational axis 318 which is perpendicular to the cutting plane.

[00340] According to embodiments of the ingot feeding system 300, which can be combined with other embodiments described herein, wherein the at least two arms 343 are arranged on opposite sides with respect to the rotational axis 318, wherein the first ends of the at least two arms 343 are connected to the support table 312 via a hinged joint.

[00341] According to embodiments of the ingot feeding system 300, which can be combined with other embodiments described herein, the kinematic mechanism structure further includes at least one slide 344, wherein the second ends of the at least two arms 343 are preferably connected to the at least one slide 344 via a hinged joint.

[00342] According to embodiments of the ingot feeding system 300, which can be combined with other embodiments described herein, the at least one slide 344 is guided via guide rails 341.

[00343] According to embodiments described herein, a wire saw system 1000 is provided, wherein the wire saw system includes at least two wire guides according to embodiments described herein, and an ingot feeding system 300 according to any embodiments of the ingot feeding system as described herein.

[00344] According to embodiments described herein, a method for feeding an ingot is provided. The method for feeding an ingot includes: feeding an ingot to a wire saw by use of a kinematic mechanism structure; monitoring a force acting on the ingot during cutting by measuring the force in the kinematic mechanism structure and/or measuring a wire bow of the wire during cutting; and controlling at least one cutting process parameter based on the monitored force and or the monitored wire bow.

[00345] According to embodiments of the method for feeding an ingot, which can be combined with other embodiments described herein, feeding an ingot may include rotating the ingot around an axis of rotation, wherein the distance D between the axis of rotation and the wire web is smaller than D = + 10 mm, particularly smaller than D = + 5 mm, particularly smaller than D = + 2.5 mm. Accordingly, by rotating the ingot around an axis of rotation which is at a distance D of smaller than D = + 10 mm from the wire web, the cutting condition of the ingot can be optimized. Particularly, the cutting condition of the ingot can be held substantially constant throughout the sawing process of the ingot.

[00346] According to embodiments of the method for feeding an ingot, which can be combined with other embodiments described herein, the axis of rotation of the ingot during sawing the ingot may be located on a curve of contact of the wire of the wire web with the ingot within a tolerance T of T = + 10 mm, particularly within T = + 5 mm, particularly within T = + 2.5 mm.

[00347] According to embodiments of the method for feeding an ingot, which can be combined with other embodiments described herein, feeding the ingot to the wire saw includes an alternating movement of the ingot, in particular a rocking movement.

[00348] According to embodiments of the method for feeding an ingot, which can be combined with other embodiments described herein, monitoring force acting on the ingot includes measuring the force based on a signal generated by at least one sensor or by at least one actuator. [00349] According to embodiments of the method for feeding an ingot, which can be combined with other embodiments described herein, the method for feeding an ingot during cutting may include monitoring a wire bow based on a signal generated by the wire bow monitoring system according to embodiments described herein.

[00350] According to embodiments of the method for feeding an ingot, which can be combined with other embodiments described herein, the controlling of at least one cutting process parameter includes a closed loop control.

[00351] According to embodiments of the method for feeding an ingot, which can be combined with other embodiments described herein, the at least one cutting process parameter includes at least one of positioning of the ingot relative to a plane perpendicular to a cutting direction during cutting, controlling an ingot feeding speed, controlling a wire speed, controlling a coolant supply, controlling a coolant temperature, controlling a rocking angle, controlling a rocking trajectory, controlling a rocking frequency, and controlling a rocking speed.

[00352] In the following, embodiments of the wire management system for the wire saw system as described herein are described.

[00353] Fig. 34 shows a schematic perspective view of a wire management system of a wire saw system according to embodiments described herein;

[00354] As exemplarily shown in Fig 34, the wire management system according to embodiments described herein includes a supply spool 134, mounted on first spool shaft 310A. The first spool shaft 310A may correspond to the spool receiving portion 215 as exemplarily described in connection with Fig. 35. Further, according to embodiments the wire management system may include a first plurality of pulleys and/or guide rollers, for example a first pulley 320A, a third pulley 330A and/or a first guide roller 315 and a second guide roller 325, which are arranged for guiding the wire from the supply spool to the cutting zone of the wire saw system.

[00355] According to embodiments which can be combined with other embodiments described herein, the wire management system 1200 includes a take-up spool 138 mounted on a second spool shaft 310B. The second spool shaft 310B may correspond to the spool receiving portion 215 as exemplarily described in connection with Fig. 35. As exemplarily shown in Fig. 34 the wire management system may include a second plurality of pulleys and/or guide rollers, for example a second pulley 320B, a fourth pulley 330B and/or a first guide roller 315 and a second guide roller 325, which are arranged to guide the wire from the cutting zone of the wire saw system to the take-up spool 138.

[00356] According to embodiments which can be combined with other embodiments described herein, the wire management system may include a first pulley moving device 324A which is configured for positioning a first pulley 320A at a desired position over the supply spool 134, as exemplarily shown in Fig. 34. Accordingly, the wire management system may include a second pulley moving device 324B which is configured for positioning a second pulley 320B at a desired position over the take-up spool 138.

[00357] According to embodiments which can be combined with other embodiments described herein, the first pulley moving device 324A and/or the second pulley moving device 324B can be configured as a retractable or telescopic bar, as indicated by the arrows in first pulley moving device and the second pulley moving device as exemplarily shown in Fig. 34. The retractable or telescopic bar can be longitudinally movable along a bar axis parallel to the spool axis. As exemplarily shown in Fig. 34, the first pulley moving device 324A and/or the second pulley moving device 324B can be mounted to a wall portion of a machine body 217 of the wire saw system.

[00358] Further, according to embodiments which can be combined with other embodiments described herein, the wire management system may include a first tension modifier 333A and/or a second tension modifier. For example, the first tension modifier 333A may be arranged at a location in the wire management system before the wire is fed to the cutting zone of the wire saw system. Accordingly, the second tension modifier 333B may be arranged at a location in the wire management system before the wire coming from the cutting zone of the wire saw system is fed to the take-up spool 138. In other words, the first tension modifier 333A may be arranged on a wire exit side of the wire management system and the second tension modifier 333B may be arranged at a wire entrance side of wire management system.

[00359] As exemplarily shown in Fig. 34, the first tension modifier 333A and/ or the second tension modifier 333B may be provided between a wire spool zone 390 of the wire management system and a wire inspection system 380. The wire inspection system may include a camera for inspecting the wire.

[00360] According to embodiments which can be combined with other embodiments described herein, the wire management system may include third pulley 330A for guiding the wire from the first pulley 320A to the first tension modifier 333A. Accordingly, the wire management system may include fourth pulley 330B for guiding the wire from the second pulley 320B to the second tension modifier 333B. The third pulley 330 A and/or the fourth pulley may be configured for measuring a force transmitted from the wire onto the third pulley 330A and/or the fourth pulley, respectively.

[00361] The first tension modifier 333 A may include a first guide roller 315 and a second guide roller 325. According to embodiments, the design of the first tension modifier 333 A may correspond to the design of the second tension modifier 333B.

[00362] According to embodiments which can be combined with other embodiments described herein, the wire management system is adapted for thin wires having a diameter below about 150 microns (μιη), such as diameters between about 100 microns (μιη) and about 150 microns (μιη), particularly between about 50 microns (μιη) and about 150 microns (μιη), more particularly between 50 microns (μιη) and 100 microns (μιη), for example 120 microns (μιη). In other cases embodiments may also have a wire diameter as low as, for example, 100 microns (μιη), 80 microns (μιη), 70 microns (μιη) or 60 microns (μιη).

[00363] Further, the wire management system as described herein may be adapted for coated wires, for example a wire having a nickel coating or resin bond with diamond particles embedded therein. Such wires may have a diameter of below about 150 microns (μιη), such as diameters between about 100 microns (μιη) and about 150 microns (μιη), particularly between about 50 microns (μιη) and about 150 microns (μιη), more particularly between 50 microns (μιη) and 100 microns (μιη), for example 120 microns (μιη). In other cases embodiments may also have a wire diameter as low as for example 100 microns (μιη), 80 microns (μιη), 70 microns (μιη) or 60 microns (μιη). For those wires a twisting of the wire might increase the risk of breakage of the wire or of damaging the coating, so that a twist-free operation is advantageous. By using diamond wire, the throughput may be increased by a factor of 2 or even more. When a diamond wire is used, further parts of the wire saw may be adapted to the diamond wire. For example, mechanical parts, electrical parts and/or software may be adapted to the use of diamond wire. When a diamond wire is used, further parts of the wire saw may be adapted to the diamond wire. For example, mechanical parts, electrical parts and / or software may be adapted for the use of diamond wire.

[00364] As described above, a plurality of pulleys are used in a wire saw system described herein. During sawing operation the pulleys may rotate with rotation speeds of more than 1500 rpm around their respective axes. According to some embodiments, the pulleys are adapted for wire saw devices by being capable of rotation speeds of 2000 rpm and more, or even 3000 rpm or more, e.g., 2000 rpm to 4000 rpm. For example, during an emergency stop the wire saw device needs to be stopped as fast as possible. Accordingly, the inertia of the pulleys, that is the moment of inertia of the pulleys, results in the rotation of the pulleys not being able to stop immediately. This further pulley rotation may result in a harmful tension on the wire such that wire breakage may occur.

[00365] Accordingly, according to embodiments, which can be combined with other embodiments described herein, a wire breakage detection system may be provided. For example, a wire breakage can be detected as follows. The wire may be biased to a potential having an absolute value of about 20 V to 120 V, particularly 30 V to 60 V. Accordingly, a voltage between the wire and remaining wire saw components such as the housing, the mainframe, and the like is generated. If the wire breaks, the loose end of the wire can touch one of the components of the wire saw, for example a pulley including electrically conductive material. The voltage between the wire and the wire saw device may result in a current. Accordingly, a wire breakage detection system may monitor the existence of such a current and detect the breakage of the wire if such a current is detected.

[00366] According to embodiments, which can be combined with other embodiments described herein, the pulleys employed in the wire saw system as described herein, particularly the pulleys of the wire management system, are made of a plastic material, particularly a thermoplastic or thermoplastic elastomer. The thermoplastic can be at least one selected from the group consisting of: Acrylnitirl-Butadien-Styrol (ABS), Polyamide (PA), Polylactat (PLA), Polymethylmethacrylat (PMMA), Polycarbonat (PC), Polyethylenterephthalat (PET), Polyethylen (PE), Polypropylen (PP), Polystyrol (PS), Polyetheretherketon (PEEK), and Polyvinylchlorid (PVC). The thermoplastic elastomer can be at least one selected from the group consisting of: polyamide, thermoplastic polyurethane (TPU), thermoplastic copolyester, thermoplastic polyamides, elastomeric alloys (TPE-v or TPV), Polyolefin blends (TPE-o) and styrenic block copolymer (TPE-s).

[00367] According to embodiments, which can be combined with other embodiments described herein, the pulleys include an electrically conductive plastic material, particularly including electrically conductive fibers.

[00368] According to embodiments, which can be combined with other embodiments described herein, the moment of inertia of the pulley is 5.0* 10 ^"4 kg*m ² or less, particularly 3.5* 10 ^"4 kg*m ² or less.

[00369] Further, embodiments of the wire management system as described herein may include a sensor arrangement 220 for monitoring the operation of the wire saw system as described herein. Exemplary embodiments of the sensor arrangement for monitoring the operation of the wire saw system are described in the following.

[00370] Fig. 35 shows a spool reception arrangement 210, for example, of the wire management system according to embodiments described herein. According to embodiments, the spool reception arrangement is adapted for receiving a spool, for example the supply spool 134 or the take-up spool 138. The spool reception arrangement may include one or more supporting surfaces or areas, one or more locking elements for fixing the spool, a motor for rotating the spool, and/or further elements for reliably holding the spool during operation. With exemplary reference to Fig. 35, the spool reception arrangement 210 may include a spool receiving portion 215 and a bearing 216. According to embodiments described herein, the spool reception arrangement 210 can be adapted for being mounted to a machine body 217 of the wire saw system. The spool receiving portion 215 can be formed like a bolt or a spike. The spool receiving portion 215 may include a surface supporting the spool.

[00371] According to embodiments which can be combined with other embodiments described herein, the spool receiving portion 215 may be configured to support a spool 250 as exemplarily shown at the right side of Fig. 35. The spool receiving portion 215 may have any shape and position, which enables a reliable support of the spool during the operation of the wire saw. According to embodiments which can be combined with other embodiments described herein, the spool receiving portion 215 may be connected to a driving device for rotation of the spool 250 mounted to the spool receiving portion 215. For example, the supply spool 134 and the take-up spool 138 may be connected to the driving device 388, as exemplarily shown in Fig. 34. The ability of the spool receiving portion 215 to support and hold a spool during operation of the wire saw is indicated in Fig. 35 with an arrow running from the spool 250 to the spool reception arrangement 210.

[00372] The spool 250, which may be mounted to the spool reception arrangement 210, may include a spool body 288. The spool body 288 may be adapted for housing a wire wound on the spool 250. According to some embodiments, the spool body 288 may be substantially cylindrical. The spool 250 can further include a spool flange at each end of the spool, for example a first spool flange 260 and a second spool flange 270 as shown in Fig. 35.

[00373] According to embodiments which can be combined with other embodiments described herein, the wire management system includes a sensor arrangement 220 for measuring the operation condition of at least one of the first spool flange 260 and the second spool flange 270 of the spool 250 to be mounted on the spool reception arrangement 210.

[00374] Fig. 36 is a front view of the spool reception arrangement shown in Fig. 35. As exemplarily shown in Fig. 36, according to embodiments which can be combined with other embodiments described herein, the sensor arrangement 220 can be mounted to an arm 224. Further, aspects with respect to the arm 224 are described in the following, for example in connection with the exemplary embodiment shown in Fig. 45. The front view of the spool shown at the right side of Fig. 36 shows the first spool flange 260 of the spool 250.

[00375] With the wire management system according to embodiments described herein, it is possible to provide an automatic measurement of the operating condition of the spool flanges and the spool stroke. The sensor arrangement used in the wire management system according to embodiments described herein is able to measure the operating condition of the spool, such as the distance between a spool flange and a surface of the spool reception (or the machine body), the distance between two flanges of a spool, the shape of a flange, the deformation of a flange and the like.

[00376] As used herein, the term "measuring a deformation" of a component may stand for measuring the shape of the component and detecting whether the shape is in an expected condition or whether the shape of the component deviates from the original shape. [00377] It has been found that one of the reasons for wire breakage is the friction of the wire against the spool flanges, and/or a situation where the wire is pinched (or blocked) between the flange and the volume of the wire wound on the spool. There are several reasons for the friction of the wire against the spool flanges or for the wire to be blocked. For instance, the stroke of the pulley moving device guiding the wire from and to the spool has to be adjusted to exactly fit the spool position. With the knowledge of the distances between the spool flanges, the wire may correctly be positioned on the spool by the pulley moving device. Accordingly, the usable space on the spool (which means going close to the flanges of the spool) whilst avoiding friction and blocking of the wire against the spool flanges can be maximized.

[00378] In known wire saws, the distances are manually measured; in particular every time a new spool is loaded on the wire saw. Accordingly, measurement errors or forgetting to perform a new setting of the parameters is a potential cause for wire breakage. Further, the operation of the wire saw is stopped for the manual measurement, which decreases the productivity.

[00379] By using a wire management system according to embodiments described herein, the measurement of the spool flange distances and shape may be made in an automatic and reliable manner. The sensor arrangement in the wire management system according to embodiments described herein, allows for a contactless measurement of the spool flange distances and the flange shape (such as for detecting a deformation). A measurement of the respective parameters during the operation of the wire saw or during a slow-down phase during the operation of the wire saw is possible by using the sensor arrangement as described herein. Also, the automatic measurement may be performed in a predetermined or selectable time interval. Thus, the measurement can be performed more often and does not have to wait until a spool is exchanged. The productivity may be increased because the operation does not have to be interrupted for the contactless measurement of the parameters. Further, the reliability can be increased as the risk of forgetting a measurement or making measurement errors due to false handling of the measurement instruments or other measurement errors is diminished.

[00380] For instance, in known systems, the spool flanges may be damaged during handling operations, such as delivery to the wire saw and the like, due to the weight of the spools. Any knock of the spool on the floor may deform the flanges, in particular the borders of the flanges. In the case that the border of a flange is deformed, friction may occur between the wire and the damaged flange which may cause wire breakage.

[00381] Another example of the problems with known systems is the high spool weight. Some spools may have a weight in the range of about 60 kg to about 80 kg. Under the pressure and the weight of the wire, the internal distance between the two spool flanges varies over time. In the case that the spool is a feeding spool, the distance between the flanges decreases when the wire is consumed and unwound from the spool. In the case that the spool is a take up spool, the distance between the flanges increases the more wire is wound on the spool. Thus, an adjustment by the pulley moving device according to the varying flange distances during operation may be beneficial.

[00382] With the wire management system according to embodiments described herein, the spool flange deformation as well as the changing flange distance may be measured. In the case of a deformed spool flange, the reliability of the automatic measurement improves the system performance. In the case of a changing flange distance, the contactless measurement of the distance during the operation ensures a correct operation of the wire saw.

[00383] Fig. 37 shows an excerpt of the wire management system with a spool 250 being mounted to the spool reception arrangement 210. The bearing 216 of the spool reception arrangement 210 can be seen in Fig. 37. The first spool flange 260 and the second spool flange 270 of the spool 250 are also shown in Fig. 37. As exemplarily shown in Fig. 37, the wire management system may include a sensor arrangement 220 adapted for measuring the operation condition of at least one of the flanges of the spool.

[00384] Fig. 38 shows a front view of the excerpt of the wire management system shown in Fig. 37. As exemplarily shown in Fig. 38, according to embodiments of the wire management system which can be combined with other embodiments described herein, the sensor arrangement 220 can be located in front of the first spool flange 260. Accordingly, the deformation of the first spool flange 260 may be measured. According to embodiments described herein, the first spool flange 260 is rotated in front of the sensor arrangement 220 while the sensor arrangement 220 measures the deformation of the first spool flange 260. For example, in case a deformation of a flange (e.g. generated by a shock or the like) is detected by the sensor arrangement 220, an alarm may be generated. In that way, the spool may be exchanged or the parameters for winding or unwinding the wire from the spool may be set accordingly, so that a wire breakage can be prevented.

[00385] According to some embodiments, which may be combined with other embodiments described herein, the sensor arrangement 220 can be provided on a moving unit, which may be adapted to move at least a part of the sensor arrangement 220 close to and from the spool flange, whose operation condition is to be measured. For example, the moving unit may be a retractable arm.

[00386] According to embodiments, which may be combined with other embodiments described herein, the wire management system as shown in Fig. 38 may be equipped with a further sensor arrangement for the second spool flange 270. With the sensor arrangements being located in front of the first spool flange 260 and the second spool flange 270, the deformation of the first spool flange 260 and the second spool flange 270 may be measured. According to embodiments, which may be combined with other embodiments described herein, the first spool flange 260 and the second spool flange 270 are rotated in front of the sensor arrangements while the sensor arrangements measure the deformation of the flange the first spool flange 260 and the second spool flange 270, respectively. If a deformation of a flange (e.g. generated by a shock or the like) is detected by one or both of the sensor arrangements, an alarm may be generated. The spool may then be exchanged or the parameters for winding or unwinding the wire from the spool may be set accordingly so that a wire breakage can be prevented.

[00387] With exemplary reference to Fig. 39, the spool reception arrangement 210 according to embodiments described herein may include a first sensor 231 and a first reference sensor 226. According to some embodiments, the first sensor 231 of the sensor arrangement 220 is located close to the first spool flange 260, while the first reference sensor 226 is located close to the second spool flange 270 of the spool 250. According to embodiments, which may be combined with other embodiments described herein, the distance between a sensor and a flange (which may be denoted as being "close" in some embodiments described herein) may be in the range of between about 1 mm and about 50 mm, more particularly between about 1 mm and about 20 mm and even more particularly between about 1 mm and about 10 mm. Additionally or alternatively, the reference sensor can be placed at a surface of the machine body 217 of the wire saw system. According to some embodiments, the reference sensor may be placed at a surface of the bearing of the spool reception arrangement 210. In particular, the first reference sensor may be placed at a surface of the machine body 217 or the spool reception arrangement 210 being substantially parallel to the flanges of the spool.

[00388] The term "substantially" as used herein may mean that there may be a certain deviation from the characteristic denoted with "substantially." For instance, the term "substantially parallel" refers to an arrangement which may have certain deviations from the exact parallel arrangement of two elements, such as a deviation of about 1° to about 10° from the exact parallel arrangement. According to a further example, the term "substantially perpendicular" may refer to an arrangement of elements which are substantially placed in a 90° arrangement to each other. The term "substantially symmetrical" may also mean that the elements are not exactly arranged perpendicularly, for example the elements may deviate from the perpendicular arrangement to some extent, e.g. to some degrees from the exact 90° position, such as 1° to about 10°.

[00389] According to embodiments, which may be combined with other embodiments described herein, the sensors described in the context of the sensor arrangement of the wire management system can be distance sensors or proximity sensors, such as, inductive sensors, capacitive sensors, laser sensors, or any type of distance sensor or proximity sensor being able to determine the distance between the sensor and a spool flange. The sensor in embodiments of the wire management system described herein may be connected to the electrical control system 1300 of the wire saw system 1000 as described herein. The measurement of the sensors may be automatic and the obtained values may automatically be loaded in the right parameters stored in the control unit. The sensors may for instance be equipped with a signal line transferring the measured parameters (such as the distance to the flange) to the electrical control system, where the parameters may accordingly be processed.

[00390] For example, the parameters obtained by the sensors can be used to check whether the spool is in a correct operation condition. The correct operation condition may depend on the shape of the spool, the distance of the flange to the spool reception, or the distance of the flanges to one another. The parameters may also be used to cause an alert in the case that the parameters indicate that the spool is not in a correct operation condition. Further, the parameters may be used to calculate further operational parameters of the wire saw system, such as parameters for operating the pulley moving device, the wire guides of the wire saw, the feeding of the workpiece to be sawed and the like. For instance, the distances of the flanges may be automatically monitored and controlled and the flange distance changes due to wire weight and wire pressure may be detected so as to adjust the stroke of the pulley moving device accordingly.

[00391] With exemplary reference to Fig. 39, according to embodiments of the wire management system which may be combined with other embodiments described herein, the first sensor 231 can be located close to the first spool flange 260 of the spool 250 for measuring the distance between the first sensor and the first spool flange. The first reference sensor 226 may measure the distance between the first reference sensor 226 and the second spool flange 270 of the spool 250. By comparing the values delivered by the sensor, the distance between the first spool flange and the second spool flange of the spool can be derived. Additionally or alternatively the distance between one flange of the first spool flange and the second spool flange of the spool and the spool reception (or the spool reception bearing or the machine body) can be derived. The first sensor 231 may measure the distance between the first sensor 231 and the first spool flange 260 over the whole circumference of the first spool flange so as to detect possible flange deformations. The same may be performed by reference to the first reference sensor 226 and the second spool flange 270.

[00392] Fig. 40 shows a spool arrangement 700 and a sensor arrangement according to embodiments which may be combined with other embodiments described herein. The spool arrangement 700 may include a first spool 701 and a second spool 702, which may be mounted to a spool reception arrangement according to embodiments as described above. The first spool 701 and the second spool 702 may correspond to the supply spool 134 and the take-up spool 138 of the wire management system according to embodiments described herein. The first spool 701 may include a first flange 703 and a second flange 704. Accordingly, the second spool 702 may include a third flange 705 and a fourth flange 706. Further, the sensor arrangement may include a plurality of sensors. In particular, a first sensor 710 may be provided and adapted for measuring the external distance to a first flange 703, a second sensor 711 may be provided and adapted for measuring the external distance to a second flange 704, a third sensor 712 may be provided and adapted for measuring the external distance to a third flange 705, and a fourth sensor 713 may be provided and adapted for measuring the external distance to a fourth flange 706. [00393] According to embodiments, which may be combined with other embodiments described herein, the sensor arrangement as exemplarily shown in Fig. 41 may be a sensor arrangement including sensors as described above in connection with Figs 35 to 39, such as distance sensors or the like. Further, although shown in an embodiment with two spools, the sensor arrangement and/or sensors described in Fig. 40 may be used in other configurations too, such as configurations for measuring only one spool or more than two spools.

[00394] The term "external distance" used herein refers to the distance to a flange measured from a reference point outside the spool, or the spool body.

[00395] Although not explicitly shown in Fig. 39, according to embodiments, which may be combined with other embodiments described herein, the first sensor 231 may be arranged between the first spool flange 260 and the second spool flange 270 of the spool 250 for measuring the distance between the first spool flange 260 and the second spool flange 270. According to embodiments, which may be combined with other embodiments described herein, at least one of the sensors for measuring distances to spool flanges as described herein may be a laser sensor. According to embodiments, which may be combined with other embodiments described herein, the sensor arrangement may include components for distance measurement by laser, such as a laser generating device, a camera, a photodiode, or a CCD device for detecting the laser beam so as to determine the distance.

[00396] According to embodiments, which may be combined with other embodiments described herein, the first sensor 231 can be arranged at the inside side of the first spool flange 260 facing the spool body 288. According to some embodiments, the position of the sensor or sensors of the sensor arrangement of a wire saw device may be chosen according to the type of sensor used, the structural environment of the wire saw, the spool type used and the like. The position of the sensor inside the spool should therefore not be understood as being limited to a laser sensor or other features specifically shown in the figures.

[00397] According to embodiments of the sensor arrangement, which may be combined with other embodiments described herein, at least one of the first sensor 710, the second sensor 711, the third sensor 712 and the fourth sensor 713 may be positioned and arranged above the spool body (e.g. at the middle position between the two flanges). Further, the first sensor 710, the second sensor 711, the third sensor 712 and the fourth sensor 713 can be positioned and configured for measuring the distance to the flanges of the first spool 701 and the second spool 702. For instance, the first sensor 710 may measure the internal distance to the first flange 703, the second sensor 711 may measure the internal distance to the second flange 704, the third sensor 712 may measure the internal distance to the third flange 705, and the fourth sensor 713 may measure the internal distance to the fourth flange 706. The internal distance as described herein refers to the distance of the sensor to an inside side of a flange, i.e. a side of the flange facing the spool body.

[00398] According to embodiments, which may be combined with other embodiments described herein, the first sensor 710, the second sensor 711, the third sensor 712 and the fourth sensor 713, may be adapted for measuring the flange deformation of the first flange 703, the second flange 704, the third flange 705, and the fourth flange 706. Further, although shown in an embodiment with two spools, the sensor arrangement and/or sensors described in Fig. 11 may be used in other configurations, too, such as configurations for measuring only one spool or more than two spools.

[00399] According to embodiments, which may be combined with other embodiments described herein, the sensor arrangement 220 may be a rotatable sensor arrangement for measuring the distances to the first flange 703, the second flange 704, the third flange 705, and the fourth flange 706, as indicated in Fig. 42 by the arrows pointing to the respective flanges. For example, the sensor arrangement 220 can be laser sensor arrangement. Further, the sensor arrangement 220 may be adapted and positioned to measure the distance to the first flange 703, the second flange 704, the third flange 705, and the fourth flange 706 by four rotations.

[00400] According to embodiments, which may be combined with other embodiments described herein, the sensor arrangement 220 may also be adapted for measuring deformation one of the first flange 703, the second flange 704, the third flange 705, and the fourth flange 706. Accordingly, the sensor arrangement 220 may stay in one position for measuring one flange condition of one flange of the first flange 703, the second flange 704, the third flange 705, and the fourth flange 706 as long as necessary for obtaining the desired information. Then, the sensor arrangement 220 may be rotated to a position for measuring a flange condition of the next flange of the first flange 703, the second flange 704, the third flange 705, and the fourth flange 706. Further, although shown in an embodiment with two spools, the sensor arrangement and/or sensors described in Fig. 42 may be used in other configurations too, such as configurations for measuring only one spool or more than two spools.

[00401] Fig. 43 shows a schematic drawing of the spool mounted to the spool reception as described herein. In Fig. 43, some examples of operation conditions of a spool flange (such as distances) are shown, which may be measured by the sensor arrangement as described in embodiments herein. For the sake of a better overview, the sensor arrangement is not shown in Fig. 43. Accordingly, the exemplary embodiment of Fig. 43 may include a sensor arrangement as described with respect to Figs. 35 to 42.

[00402] According to some embodiments, the distance of the wire saw device, which may be measured by the sensor arrangement as described herein, may be a first distance 810 between the first spool flange 260 and the second spool flange 270. In one embodiment, the first distance 810 is measured at the inside side of the first spool flange 260 and the second spool flange 270 (facing the spool body 288), e.g. by using a laser sensor. The measurement of the distance between the first spool flange and the second spool flange of a spool may be performed at the outside side of the flanges (not facing the spool body 288), e.g. by using a sensor arrangement including two proximity sensors.

[00403] According to embodiments, which may be combined with other embodiments described herein, the distance which may be measured by the sensor arrangement as described herein, may be a second distance 820 between the first spool flange 260 and the bearing 216 of the spool reception. For instance, the second distance 820 may be measured by a laser sensor or a proximity sensor. In one embodiment, the second distance 820 may be the distance between a flange of the spool (such as one of the first spool flange 260 or the second spool flange 270) and a surface of the bearing, in particular a surface of the bearing 216 being substantially parallel to the flange of the spool. In the embodiment shown in Fig. 43, the second distance 820 is measured from an outside side of the first spool flange 260 to the bearing 216; alternatively the second distance may also be measured from the inside side of the first spool flange.

[00404] According to embodiments, which may be combined with other embodiments described herein, the distance which may be measured by the sensor arrangement as described herein, may be a third distance 830 as exemplarily shown in Fig. 43. The third distance 830 may extend from a flange of the spool (here exemplarily the first spool flange 260) to the machine body 217 of the wire saw device. Although the third distance 830 is shown as extending from the outside side of the first spool flange 260, the third distance 830 may also be measured from the inside side of the first spool flange 260, or from the second spool flange 270. As mentioned above, a laser sensor or a proximity sensor may be used for performing the measurement of third distance 830.

[00405] In Fig. 43, an enlarged view of the first spool flange 260 of spool 250 is shown. According to some embodiments, which may be combined with other embodiments described herein, the operational parameter measured by the sensor arrangement may be a deformation 840. In Fig. 43, the deformation 840 is exemplarily shown as a bending of the flange border. The deformation in the example shown in section A of Fig. 43 includes a deviation of the flange shape by an angle 841. Although only shown for the first spool flange 260, the deformation of the second spool flange 270 may also be measured by the herein described sensor arrangement as operation condition of the flanges. It should be noted that the skilled person will understand how to modify the shown example so as to apply the measurement to the deformation of the second spool flange 270, or to deformations having a different shape or position than the deformation 840 as exemplarily shown in Fig. 43.

[00406] Fig. 44 shows an excerpt of a wire management system having a spool arrangement according to embodiments described herein including a first spool reception arrangement and a second spool reception arrangement. The first spool reception arrangement may include a first bearing 616 and the second spool reception arrangement may include a second bearing 618. The first and the second spool reception arrangement may be connected to a machine body 217. The first spool reception arrangement can be adapted for holding and supporting a first spool 701, and the second spool reception arrangement can be adapted for holding and supporting a second spool 702. According to embodiments, which may be combined with other embodiments described herein, first spool 701 may be the supply spool 134 providing the wire for the wire saw system, and the second spool 702 may be the take-up spool 138 for taking up the used wire after the sawing process.

[00407] According to embodiments, which may be combined with other embodiments described herein, the sensor arrangement 220 includes a first sensor 231 for measuring an operation condition of a second flange 704 of the first spool 701 and a first reference sensor 226 for providing a reference for the measurement of the first sensor 231. Further, as exemplary shown in Fig. 44, the sensor arrangement 220 may include a second sensor 232 for measuring an operation condition of the fourth flange 706 of the second spool 702 and a second reference sensor 627 for providing a reference for the measurement of the second sensor 232. According to embodiments, which may be combined with other embodiments described herein, the distance (indicated with reference number 623) between the first sensor 231 and the second sensor 232 of the sensor arrangement in a direction substantially perpendicular to the measuring direction of the sensors, may be in the range of particularly between about 100 mm and about 300 mm, more particularly between about 150 mm and about 280 mm, and even more particularly between about 180 mm and about 250 mm.

[00408] Fig. 45 shows a front view of the spool arrangement of Fig. 44. In the front view of Fig. 45, it can be seen that according to some embodiments described herein the first sensor 231 and the second sensor 232 can be mounted to a support 628. The support 628 can be connected to an arm 224. The arm 224 may be used as a moving unit. According to some embodiments, which may be combined with other embodiments described herein, the arm, on which the sensors of the sensor arrangement are provided, may be a moving unit, such as a retractable arm. The retractable arm may carry at least one sensor of the sensor arrangement as described herein.

[00409] As exemplarily shown in Fig. 45, according to embodiments which may be combined with other embodiments described herein, the first reference sensor 626 and the second reference senor 627 can be mounted to the first bearings 616 and the second bearing 618, respectively. The arrangement of the sensors shown in the embodiment of Figs. 44 and 45 allows for the simultaneous measurement of more than one spool in the wire management system as described herein. For instance, the operation condition of the flanges of a supply spool and a take-up spool may be measured simultaneously.

[00410] By providing a sensor of the sensor arrangement on a moving unit, the sensor may be moved to and removed from the spool flange during operation. According to some embodiments, the retractable arm carrying a sensor of the sensor arrangement may be moved to the spool flange during a slow-down phase during the operation of the wire saw. For instance, the velocity of rotation of the spool may be decreased and the sawing process is shortly suspended or postponed so that the measurement of the operating condition of the flange may be measured by moving a sensor in front of the respective spool flange. After the measurement, the moving unit may be removed or retracted from the spool flange so as not to disturb the winding and unwinding process.

[00411] According to embodiments, which may be combined with other embodiments described herein, the retractable arm may include a bellow, which is able to extend and retract, e.g. by a pneumatic mechanism. The bellow-like structure of the arm 224, particularly of the retractable arm, is exemplarily shown by vertical lines in Fig. 45. According to some embodiments, which may be combined with other embodiments described herein, the retractable arm may be compressed in order to move the sensors in a direction away from the flanges. The bellow-like structure of the retractable arm may be made of a flexible material, which may be folded along the vertical lines, when the retractable arm is retracted. The flexible material of the bellow-like structure may be able to unfold when the retractable arm is extended. In one embodiment, the retractable arm may be extendable and retractable in a range of particularly between about 100 mm to about 300 mm, more particularly between about 150 mm and about 280 mm, even more particularly between about 200 mm and 250 mm. In one example, the retractable arm may be extendable and retractable by about 230 mm.

[00412] According to embodiments, which may be combined with other embodiments described herein, the length of the retractable arm (such as, in Fig. 45, the length 624 of the arm 224) may be in the range of particularly about 200 mm to about 600 mm, more particularly between about 250 mm and about 500 mm, and even more particularly between about 300 mm and about 500 mm. In one example, the length of the retractable arm is about 420 mm.

[00413] It should be noted that values described above with respect to dimensions of elements described in embodiments herein may depend on the size of the wire saw. Thus, the above dimensions and values are not limiting and may vary dependent on the wire saw, in which the wire saw device according to embodiments described herein may be used.

[00414] Fig. 46 shows a schematic view of an excerpt of a wire saw system according to embodiments described herein. The wire saw system includes a wire management system which may include a first spool 701, for example the supply spool of the wire management system as described herein. According to embodiments described herein, the wire 11 is guided from the wire management system to the first wire guide 112 and the second wire guide 114 by which a wire web in the cutting zone may be formed. In the cutting zone an ingot may be cut in wafers or thin slices as described herein. After having passed the cutting zone, the wire 11 is guided to a second spool 702, for example the take up-spool of the wire management system for receiving the wire after the cutting process. The flanges of the first spool 701 and the second spool 702 may be measured by a sensor arrangement 220 as described herein.

[00415] Further, according to embodiments described in connection with Figs. 35 to 46 a method for measuring the operation condition of a wire saw system according to embodiments described herein is provided. According to embodiments of the method for measuring the operation condition of a wire saw system, the method includes providing a spool reception arrangement for receiving a spool, which includes one flange at each end of the spool. Further, the method may include measuring the operation condition of at least one of the spool flanges by a sensor arrangement. The sensor arrangement used for measuring the operation condition of the flange may be a sensor arrangement as described above with respect to Figs. 35 to 46. Further, the sensor arrangement may include one or more proximity sensors or laser sensors as described above. It is to be understood that, sensor arrangement may include any type of distance sensor allowing the distance to the flange to be measured in a contactless manner.

[00416] According to embodiments, which may be combined with other embodiments described herein, the method includes measuring the distance between a flange of the spool and a surface of the spool reception arrangement. Further, the distance between a flange of the spool and a surface of the spool reception arrangement being substantially parallel to the flange may be measured. Additionally or alternatively, the distance between the two spool flanges of one spool may be measured. Further, the method for measuring the operation condition of a wire saw system may include measuring the deformation of one of the spool flanges. In particular, the deformation of one of the spool flanges may be measured by measuring the distance of the sensor to the flange over the whole circumference of the flange.

[00417] According to some embodiments, measuring the operation condition of a spool flange includes moving the sensor arrangement to the spool flange for measuring the operation condition of the spool flange. For instance the sensor arrangement may be moved by a moving unit to the flange, such as a moving unit or a retractable arm as described above. The moving unit may move the sensor arrangement close to the flange. The exact distance from the sensor to the flange may depend on the sensor used and the size and the material of the flange. In particular, the sensor arrangement is moved towards the flange for measuring the operation condition of the spool flange in a contactless manner.

[00418] According to embodiments, which may be combined with other embodiments described herein, measuring the operation condition of the spool flange(s) may be performed during the operation of the wire saw system as described herein. For instance, the moving unit carrying at least a part of the sensor arrangement is driven (such as by a pneumatic mechanism) so as to place the sensor close to the spool flange, whose operational condition is to be measured. Moving the part of the sensor arrangement carried by the moving unit to the flange may be performed during operation of the wire saw device or during a slow-down phase during the operation of the wire saw system. In this way, the sensor arrangement may be provided on demand if a measurement may be conducted or the control unit indicates the expiry of a predefined time period after which a measurement of the operational condition of the spool flange is due.

[00419] By using embodiments of the wire saw management system described herein, the distance between the flanges or the distance between the flange and the machine body may be detected. Additionally, further sources of errors during the wire saw operation may be detected. For instance, sliding of the spool on the spool reception, a deformation of the flange, or a wrong type of spool being installed may be detected.

[00420] According to embodiments described herein a wire management system 1200 is provided. The wire management system includes a spool reception arrangement 210 for receiving a spool 250, the spool including a spool flange at each end of the spool; and a sensor arrangement 220 for measuring the operation condition of at least one of the spool flanges.

[00421] According to embodiments of the wire management system 1200, which can be combined with other embodiments described herein, the wire management system further includes a moving unit, in particular a retractable arm, wherein at least a part of the sensor arrangement 220 is mounted to the moving unit. [00422] According to embodiments of the wire management system 1200, which can be combined with other embodiments described herein, the sensor arrangement 220 is configured for measuring at least one of the shape and the position of at least one of the spool flanges.

[00423] According to embodiments of the wire management system 1200, which can be combined with other embodiments described herein, the sensor arrangement 220 is configured for measuring the operation condition comprising at least one of the group consisting of: the distance between at least one of the flanges of the spool and a surface of the spool reception arrangement 210, the distance between the two flanges of one spool, and the deformation of at least one of the spool flanges.

[00424] According to embodiments of the wire management system 1200, which can be combined with other embodiments described herein, the spool reception arrangement includes a first spool reception for receiving a supply spool for providing a wire and a second spool reception for receiving a take-up spool for receiving the wire. The sensor arrangement 220 is configured for measuring the operation condition of at least one of the spool flanges of the supply spool and the operation condition of at least one of the spool flanges of the take-up spool.

[00425] According to embodiments of the wire management system 1200, which can be combined with other embodiments described herein, the sensor arrangement 220 includes at least one sensor adapted for measuring the operation condition of the supply spool and at least one sensor for measuring the operation condition of the take-up spool.

[00426] According to embodiments of the wire management system 1200, which can be combined with other embodiments described herein, one sensor for the supply spool 134 and one sensor for the take-up spool 138 are mounted to the moving unit.

[00427] According to embodiments of the wire management system 1200, which can be combined with other embodiments described herein, wherein the wire management system includes a machine body 217 configured for providing the spool reception arrangement 210 and wherein the sensor arrangement includes a reference sensor device at least at one of the machine body and the spool reception arrangement. [00428] According to embodiments of the wire management system 1200, which can be combined with other embodiments described herein, the sensor arrangement further includes a sensor device mounted to the moving unit.

[00429] According to embodiments of the wire management system 1200, which can be combined with other embodiments described herein, the sensor arrangement includes at least one of a proximity sensor, a laser sensor and a rotatable sensor.

[00430] According to embodiments described herein, a method for measuring the operation condition of a wire saw system 1000 as described herein is provided. Particularly, the wire saw system includes a wire management system having a spool reception arrangement 210 for receiving a spool 250 including one flange at each end of the spool. The method for measuring the operation condition of a wire saw system 1000 includes measuring the operation condition of at least one of the spool flanges by a sensor arrangement 220.

[00431] According to embodiments of the method for measuring the operation condition of a wire saw system, which can be combined with other embodiments described herein, measuring the operation condition of at least one of the spool flanges includes at least one of measuring the distance between at least one of the flanges of the spool and a surface of the spool reception arrangement, measuring the distance between the spool flanges of one spool, and measuring the deformation of one of the spool flanges.

[00432] According to embodiments of the method for measuring the operation condition of a wire saw system, which can be combined with other embodiments described herein, measuring the operation condition of at least one of the spool flanges comprises moving at least a part of the sensor arrangement to the spool flange for measuring the operation condition of the spool flange, in particular for measuring the operation condition of the spool flange in a contactless manner.

[00433] According to embodiments of the method for measuring the operation condition of a wire saw system, which can be combined with other embodiments described herein, measuring the operation condition of at least one of the spool flanges is performed during the operation of the wire saw, in particular during a slow-down phase during the operation of the wire saw. [00434] Further, according to embodiments described herein, a method for operating a wire saw system 1000 as described herein is provided. The method for operating a wire saw system includes: providing a wire from a spool for sawing a work piece, wherein the spool includes a spool flange at each end of the spool; and measuring the operation condition of at least one of the spool flanges according to any embodiments of the method for measuring the operation condition of a wire saw as described herein.

[00435] In the following, embodiments of a tension modifier, particularly for a wire management system as described herein are described.

[00436] As exemplarily shown on Fig. 34, according to embodiments described herein the wire management system 1200 may include at least one tension modifier, particularly a first tension modifier 333 A and a second tension modifier 333B.

[00437] In the present disclosure the term "tension modifier" may be understood as an arrangement which is adapted for converting a wire tension in a wire saw device and for adjusting the wire tension. In other words, the tension modifier as understood herein is adapted to convert the wire tension and, at the same time, to adjust the wire tension the meaning of which will be explained in the following in more detail.

[00438] In the present disclosure in context with embodiments of the tension modifier as described herein, the term "to convert" may be understood as an action for converting a wire tension for a wire saw device, i.e. to increase or to decrease the wire tension across orders of magnitude. For instance, tension conversion can be done from a tension of below 10 N or even 8 N, to a tension of more than 10 N. For instance, the tension may be converted from a tension between 2 and 8 N to a tension of between 10 and 20 N, for example 15 N, or to a tension of between 22 N and 32 N, for example 28 N.

[00439] In operation, the tension modifier may particularly convert the tension always in the same direction. For instance, the wire tension of the wire entering the tension modifier may be lower or higher than the wire tension of the wire exiting the tension modifier by orders of magnitude.

[00440] According to embodiments of the tension modifier which can be combined with other embodiments described herein, the wire tension of a wire which is guided in the grooves of the first guide roller and the second guide roller of the tension modifier can be progressively increased or reduced with each subsequent groove winding that the wire passes. The tension modifier may be operated such that the wire tension can be increased or decreased with low friction generation between the wire and the grooves.

[00441] The tension modifier may convert the wire tension of the wire on the conventional supply spool (as explained in more detail below) into a wire tension which is necessary for the actual cutting in the cutting zone. Additionally or alternatively, the tension modifier may convert the wire tension in the cutting zone into a wire tension which is desired for winding up the used wire on the take-up spool. As a result, the wire on the spools, e.g. the feed spool and the take-up spool, may be unwound/wound up under a lower tension than the tension necessary to cut the semiconductor material.

[00442] Further, according to embodiments, the tension modifier can be adapted to adjust a wire tension. Adjusting a wire tension may be understood as adapting the wire tension by small magnitudes in order to keep the wire tension constant. The adjusting action of the tension modifier may be done actively by one or more actuators. In some embodiments, the adjusting action may be done reactively.

[00443] An active adjusting action may be induced by a control device, e.g. the electrical control system 1300 of the wire saw system as described herein, which controls one or more actuators included in the tension modifier according to a measured wire tension.

[00444] According to embodiments of the tension modifier which can be combined with other embodiments described herein, the tension modifier may be adapted to keep the desired wire tension constant for the actual cutting action or the winding-up process of the wire. The tension modifier can particularly be adapted to compensate for fluctuations of the wire tension. Such tension fluctuations may, for example, occur due to disturbances in the cutting process, due to the inertia of rotating elements, such as wire guides, in particular in case of a back and forth movement of the wire. Such perturbations may also occur due to conversion of the wire tension, due to oscillations in the wire, or the like.

[00445] In the present disclosure, the tension of the wire may also be referred to as wire tension. According to embodiments which can be combined with other embodiments described herein, the wire tension in the cutting zone of the wire saw can be set at a certain value in order to ensure efficient cutting with a high throughput and low wire damage. Commercially available wire spools with unused wire provide a wire tension being significantly lower than the wire tension necessary for the cutting action in the cutting zone of the wire saw.

[00446] Conventionally, before using the wire provided on such a conventional spool, the wire has to be unwound from the conventional spool and rewound onto a wire feed spool which is made of a material or is reinforced by a material withstanding the wire tension needed for the cutting action.

[00447] After traveling through the cutting zone of the wire saw, the tensioned wire exits the cutting zone and is wound up on a take-up spool. Conventionally, the take-up spool is made of a material or is reinforced by a material withstanding the wire tension of the wire exiting the cutting zone. Further, conventionally after cutting, the used wire is unwound from the take-up spool and rewound onto another spool which is then disposed together with the used wire.

[00448] It has been found that the above-described winding and unwinding actions lead to undesired effects. In particular, the above-described winding and unwinding actions before and after the actual cutting action are additional operations which are time-consuming and add up to the actual man-power involved in the overall wafer production. Further, winding the wire on the wire supply spool under tension before cutting may lead to premature damage in the wire due to a high contact pressure of the tensioned wound wire. The so caused defects may lead to saw marks and variation in the wire diameters during cutting. Accordingly, the cutting quality may be decreased. Moreover, the wire spools, e.g. the supply spool and the take-up spool, need to be designed for the application of a wire having high tension. Accordingly, a reinforced design may be necessary for the wire spools. Such specially designed spools may increase manufacturing and material costs.

[00449] Accordingly, by providing a wire management system including a tension modifier according to embodiments described herein, at least some of the drawbacks outlined above may be overcome. According to embodiments described herein a tension modifier is provided which is configured for converting a first wire tension into a second wire tension. According to some embodiments of the tension modifier, the first wire tension may be higher than the second wire tension. According to other embodiments of the tension modifier, the first wire tension may be lower than the second wire tension. The first wire tension may be, for example, the wire tension of the wire entering the tension modifier. Alternatively, the first wire tension may be the wire tension of the wire exiting the tension modifier.

[00450] According to embodiments which can be combined with other embodiments described herein, the first wire tension may be the wire tension in the cutting zone and the second wire tension may be the wire tension in the wire spool zone of the wire management system. Alternatively, the first wire tension may be the wire tension in the wire spool zone of the wire management system and the second wire tension may be the wire tension in the cutting zone. According to embodiments which can be combined with other embodiments described herein, the tension modifier may be located between the wire spool zone of the wire management system and the cutting zone of the wire saw system.

[00451] Accordingly, with a wire saw system including a tension modifier according to embodiments described herein, it may not be necessary to unwind unused wire from a commercially available wire spool and/or rewind the wire onto a high tension withstanding wire spool. Accordingly, the conventional wire spool may directly be used as a wire supply spool to feed the wire to the cutting zone. In embodiments described herein, the unused wire on the conventional spool may be fed to the tension modifier. According to embodiments described herein, the tension modifier may receive the wire directly or via one or several pulleys from the conventional wire feed spool.

[00452] According to embodiments of the tension modifier which can be combined with other embodiments described herein, the difference between the first wire tension and the second wire tension is at least 5 N, optionally at least 10 N, optionally at least 15 N. According to embodiments described herein, the difference between the first wire tension and the second wire tension is no more than 25 N, optionally no more than 20 N, optionally no more than 15 N.

[00453] The first wire tension may be in the range of 1 N and 10 N and the second wire tension may be in the range of 10 N and 35 N. In other embodiments, the second wire tension may be in the range of 1 N and 10 N, and the first wire tension may be in the range of 10 N and 35 N.

I l l [00454] According to embodiments which can be combined with other embodiments described herein, the tension modifier can be adapted to convert the wire tension in the cutting zone to at least 10 N, particularly to at least 12 N and more particularly to at least 15 N. As a result, a conventional wire spool, even with low wire tension, may be used as the supply spool. By converting the low wire tension in the wire spool zone of the wire management system into a higher wire tension for the cutting zone, efficient cutting of semiconductor material may be achieved. In other words, the tension modifier according to embodiments described herein is adapted to convert the wire tension of the wire from the wire supply spool into a wire tension which is suitable for the application in the cutting zone, i.e. for the actual cutting action.

[00455] According to embodiments of the wire management system which can be combined with other embodiments described herein, the take-up spool is made of a cost- effective material. A cost-effective material can be incapable of withstanding a wire having a high wire tension, such as the wire tension in the cutting zone, in particular with tensions resulting from a wire that is, to exemplarily indicate an order of magnitude, 1000 km long and coiled at a tension of 10 N or more. The tension modifier according to embodiments described herein may be adapted to convert the wire tension of the wire in the cutting zone into a wire tension which the take-up spool can withstand. According to embodiments described herein, the tension modifier is adapted to convert the wire tension in the wire spool zone of the wire management system to 10 N at maximum, particularly to 8 N at maximum and more particularly to 5 N at maximum.

[00456] By providing a wire saw system with a wire management system including a tension modifier as described herein the productivity of the wire saw system, the overall through-put and the feed rate can be optimized, by reducing the number of windings and unwindings of the spools. Accordingly, embodiments of the wire saw system as described herein provide for reducing the ratio of hours of manpower per wafer cut.

[00457] Fig. 47 shows a schematic view of a tension modifier 333 according to embodiments described herein. The tension modifier may include a first guide roller 315 and a second guide roller 325. The first guide roller 315 includes an axis of rotation 45 and a plurality of grooves 155. The grooves 155 are formed in an outer circumferential surface of the first guide roller 315. The second guide roller 325 also includes a plurality of grooves 155. [00458] Accordingly, the first guide roller 315 and the second guide roller 325 of the tension modifier may be formed in an outer circumferential surface of the first and the second guide roller. As illustrated in Fig. 47, the grooves may be arranged in parallel. Each groove may complete a 360° revolution around the outer circumferential surface of the first guide roller and the second guide roller, respectively.

[00459] According to embodiments which can be combined with other embodiments described herein, the pitch D2 of the grooves of the first guide roller 315 and the second guide roller 325 of the tension modifier can be between 1.0 mm and 2.0 mm, or larger, for example more than 5 mm. Each of the guide rollers of the tension modifier may include between 5 and 25 grooves, such as between 10 and 20 grooves.

[00460] According to embodiments which can be combined with other embodiments described herein, the grooves 155 are adapted to guide the wire 11. The grooves 155 on the first guide roller 315 and the grooves 155 on the second guide roller 325 may run in parallel to each other. Wire 11 may build several windings around the first guide roller 315 and the second guide roller 325. One winding may be defined by the wire 11 circulating around approximately half of the circumferential surface of the first guide roller 315 and approximately half of the circumferential surface of the second guide roller 325. In other words, the wire 11 is wound around the first guide roller 315 and the second guide roller 325 so that the wire 11 builds a U-shaped loop around each of the first guide roller 315 and the second guide roller 325 with every winding. The grooves 155 of the guide rollers may be distributed approximately equidistantly along the longitudinal direction of the guide rollers, for example the first guide roller 315 and the second guide roller 325.

[00461] According to embodiments which can be combined with other embodiments described herein, the first guide roller 315 has an axis of rotation 45 around which the second guide roller 325 may be pivoted. The center of the first guide roller 315 and the center of the second guide roller 325 can be spaced apart from each other at a fixed distance L. The fixed distance L forms a connection arm for the second guide roller 325. The fixed distance L can be larger than the sum of the radiuses of the first guide roller and the second guide roller. The distance may have a length of between 10 cm and 30 cm, particularly between 15 cm and 25 cm. In particular, the distance may be no larger than 10 cm or even only 5 cm in addition to the sum of the radius of the first guide roller and the second guide roller. [00462] The selection of a distance L that is not extensively large has the effect that the lever of the connection arm and the second guide roller pivoting around the first guide roller does not become too large. It is to be understood that the length of the distance between the guide rollers has an effect on the angle taken by the wire to pass from a groove to another on the opposite roller guide. The angle is inversely proportional to the length of the connection arm, and is a parameter for the lifetime of the roller guide.

[00463] According to embodiments of the tension modifier, which can be combined with other embodiments described herein, the tension modifier may be designed for adjusting the wire tension. Accordingly, the wire tension may be regulated in order to compensate fluctuations of the wire tension which may occur during the sawing process, such as fluctuations due to the conversion of the wire tension. Adjusting the wire tension may include increasing or decreasing the wire tension of the wire.

[00464] For instance, the tension modifier may be used to convert the wire tension by 10 N. It is to be noted that in practice the conversion of the wire tension by 10 N may not be constant and may, for example, vary between 9 N and 11 N in order to compensate for fluctuations, oscillations, or inertia. For example, the desired tension of the conversion may be varied in practice up to +/- 10% or up to 5%. According to embodiments described herein, the wire tension in the cutting zone may be constant. Additionally or alternatively, the wire tension in the spooling zone may be constant.

[00465] The width of the at least one guide roller in the axial direction of the at least one guide roller may be in the range between 3 cm and 30 cm, optionally between 3 cm and 10 cm.

[00466] According to embodiments which can be combined with other embodiments described herein, at least one of the first guide roller 315 and the second guide roller 325 may rotate freely on their axis of rotation. Additionally or alternatively, at least one of the first guide roller 315 and the second guide roller 325 may be actuated by an actuator, for example a brushless motor.

[00467] For example, an actuator may particularly be provided at the first guide roller that is provided with a stationary axis of rotation. Hence, even in the embodiments where the second guide roller is pivotable about the axis of the first guide roller, the provision of an actuator does not increase the inertia of the moving parts of the tension modifier as it would be the case if an actuator was provided at the second guide roller whose axis of rotation is non- stationary and pivotable around the axis of rotation of the first guide roller in these embodiments. Further, according to embodiments, an actuator at the second guide roller may be provided, which can be pivotable around the axis of rotation of the first guide roller.

[00468] According to embodiments, one actuator is provided on the connection arm between the first guide roller and the second guide roller. The actuator in this embodiment may cause the actuation of the pivoting movement of the connection arm about the axis of the first guide roller. The second guide roller may be non-actuated, for instance, driven by the wire moving the guide roller. Further, another actuator may be provided to actuate the first guide roller.

[00469] Fig. 48 shows a perspective view of embodiments of a tension modifier 333, according to embodiments described herein. According to embodiments which can be combined with other embodiments described herein, the first guide roller 315 can be actuated by an actuator, such as a brushless modifier. The first guide roller 315 may be actuated by a motor and may rotate around its axis of rotation 45. The second guide roller 325 may not be actuated and may freely rotate around an axis of rotation 26. Alternatively, the second guide roller may be actuated.

[00470] Furthermore, as exemplarily illustrated in Fig. 48, the second guide roller 325 may be pivotable around both the axis of rotation 26 of the second guide roller 325 and the axis of rotation 45 of the first guide roller 315. In particular, for example, in addition to the actuation of the first guide roller, an actuator (not shown) may be provided for pivoting the second guide roller 325 around the axis of rotation 45 of the first guide roller 315, as indicated by the double-headed arrow 49. Independent of whether the first guide roller and/or the second guide roller is actuated; the maximum angle of the second guide roller pivoting around the axis of rotation of the first guide roller may be +/-35 ⁰ .

[00471] According to embodiments which can be combined with other embodiments described herein, at least one of the first guide roller 315 and the second guide roller 325 has a cylindrically shaped body. The cylindrically shaped body of the at least one of the first guide roller 315 and the second guide roller 325 may have a diameter in the range of between 10 cm and 25 cm, in particular between 12 cm and 20 cm. Fig. 48 illustrates the first guide roller 315 and the second guide roller 325 having both a cylindrically shaped body. In Fig. 48, the diameter of the cylindrically shaped body of the first guide roller 15 is denoted by reference number 14D and the diameter of the cylindrically shaped body of the second guide roller 25 is denoted by reference number 24D.

[00472] According to embodiments, the shape of the guide rollers of the tension modifier as described herein may be conical. For instance, the diameter at one side of the first and/or second guide roller may be between 0.5 mm and 10 mm, optionally between 0.5 mm and 4 mm larger than the diameter at the opposite side of the first and/or second guide roller. A conical shape has the effect that slipping of the wire on the surface of the guide rollers may be reduced or avoided, reducing the wear out of the guide rollers. In addition, where there is less or no slipping on the guide rollers, there is also less risk of the wires to jump out of the groove.

[00473] According to embodiments which can be combined with other embodiments described herein, at least 5 grooves, particularly at least 10 grooves may be formed in the respective outer circumferential surface of the first guide roller 315 and the second guide roller 325. The first and/or second guide roller may have no more than 20 grooves. The grooves can be arranged parallel to each other. In particular, the grooves in embodiments of the first guide roller and/or second guide roller can be non-helical.

[00474] As exemplarily shown in Fig. 48, according to embodiments which can be combined with other embodiments described herein, the first guide roller 315 and the second guide roller 325 may be connected to each other through a connection arm 35, particularly by a connection arm. The connection arm 35 forms a fixed distance between the first guide roller 315 and the second guide roller 325. In embodiments described herein, the connection arm between the first guide roller 315 and the second guide roller 325 may form a pivotable lever arm for adjusting the wire tension. For example, the second guide roller may pivot around the axis of the first guide roller. Additionally or alternatively, the first guide roller may also pivot around the axis of the second guide roller. Accordingly, through the pivoting movement, tension variations and fluctuations can be cleared.

[00475] According to embodiments which can be combined with other embodiments described herein, the wire tension may be adjusted by pivoting the second guide roller 325 together with the connection arm 35 around the axis of rotation 45 of the first guide roller 315. In embodiments, the connection arm 35 may engage at the axis of rotation 45 of the first guide roller 315. By deflecting the connection arm 35, i.e. by pivoting the second guide roller 325 around the axis of rotation 45 of the first guide roller 315, the wire tension of the wire may be adjusted.

[00476] Fig. 49 exemplarily illustrates a detailed view of a guide roller in particular, of the first guide roller 315 and or the second guide roller 325 as described in the embodiments illustrated in the figures. Fig. 49 shows a guide roller which is rotatable around an axis of rotation 370. The guide roller is provided with a plurality of peripheral grooves 400 for receiving a wire. For instance, the peripheral grooves 400 may correspond to the grooves 155 as described previously. The peripheral grooves 400 wind around the conically shaped body of the guide roller. In embodiments described herein, the peripheral grooves 400 include at least 2 windings, particularly at least 5 windings. Particularly, the guide roller includes less than 30 windings, in particular less than 20 windings.

[00477] According to embodiments, which can be combined with other embodiments described herein, each winding can be formed by a root 340, two crests 353 and two flanks 345. The two flanks make an angle ε which is denoted by reference number 360 herein. According to embodiments, each winding of the peripheral groove 400 may have a width in a cross direction of the conically shaped body, a depth in a radial direction of the conically shaped body and a pitch 330 from the center of one winding to the center of an adjacent winding. The width may be determined by the distance between two adjacent crests surrounding a winding.

[00478] Particularly, according to embodiments which can be combined with other embodiments described herein, the width of the windings may be in the range of 100 microns (μιη) to 500 microns (μιη). The depth may be determined by the distance between one of the crests 353 and the root 340 of a winding. Particularly, the depth of the windings may be in the range of 100 microns (μιη) to 500 microns (μιη). The pitch 330 may be determined by the distance between the center of one winding to the center of an adjacent winding. Particularly, the pitch may be in the range of between 1 mm to 5 mm.

[00479] According to embodiments which can be combined with other embodiments described herein, the width of the guide roller in an axial direction, which is denoted by 301 in Fig. 49, is between 1 cm and 20 cm, particularly between 3 cm and 10 cm. [00480] According to embodiments which can be combined with other embodiments described herein, the guide roller, for example the first guide roller and/or the second guide roller of the tension modifier, may have a first diameter on a first axial end and a second diameter on a second axial end. The first diameter can be larger than the second diameter by at least 1 mm, optionally by at least 2 mm or even 5 mm. The first diameter may be larger than the second diameter by less than 10 mm. The first diameter and/or the second diameter may be at least 10 cm. The relative difference in the diameters, i.e. the difference in diameters in relation to the larger one of the first or second diameter is particularly at or below 1%. Having differing diameters on each end, not limited to the values exemplarily given in the previous sentence, the guide roller has a conical shape. Accordingly, the body of the converting roller may be defined designated as a conically shaped body.

[00481] According to embodiments which can be combined with other embodiments described herein, the first diameter, the second diameter or the average value of the first diameter and the second diameter of the guide roller is at least two times, particularly at least three times, as large as the width of the guide roller in the axial direction 301 illustrated by the arrow in Fig. 49.

[00482] As exemplarily shown in Fig. 49, according to embodiments described herein the guide roller may have a first end 302 and a second end 303 located opposite each other. The first end 302 may have a first diameter 411 which is determined by the diameter confined by the crest of the first winding on the first end 302. Accordingly, the second end 303 may have a second diameter 310 which is determined by the diameter confined by the crest of the first winding on the second end 303. The diameters may be in the range of between 5 cm and 30 cm, in particular between 10 cm and 20 cm.

[00483] According to embodiments, the first diameter 411 on the first end 302 may be larger than the second diameter 310 on the second end 303 by a factor of at least 1.001. Additionally or alternatively, the first diameter 411 on the first end 302 may be larger than the second diameter 310 on the second end 303 by a factor of at most 1.1.

[00484] According to embodiments which can be combined with other embodiments described herein, the diameter increases constantly in the axial direction 301 of the conically shaped body from the first end 302 to the second end 303 of the guide roller. The diameter which progressively increases from the first end 302 to the second end 303 compensates for a wire elongation from the first end 302 to the second end 303 due to the difference in the wire tension. Such a wire elongation occurs, for example, in a case in which a wire tension is converted from a lower tension zone into a higher tension zone or vice versa. The extent to which a wire may be elongated due to the wire tension is dependent on the wire material and the diameter.

[00485] According to embodiments which can be combined with other embodiments described herein, the diameter may increase inconstantly in a longitudinal direction of the conically shaped body from the first end 302 to the second end 303. For example, the increase of the diameter may be realized in individual stages.

[00486] Fig. 50 shows a schematic excerpt of a wire saw system according to embodiments as described herein for illustrating the principle of the tension modifier as described herein. The tension modifier may be positioned at different locations in the wire saw system. In the exemplary embodiment shown in Fig. 50, the tension modifier 333 is positioned between the take-up spool 138 and the cutting zone 240. The first wire tension represents the wire tension in the cutting zone 240. The second wire tension represents the wire tension in the wire spool zone 390. As described above, the tension modifier 333 is adapted to convert the wire tension of the wire in the cutting zone 240 so that the wire tension of the wire 11 in the wire spool zone 390 is smaller than the wire tension of the wire 11 in the cutting zone 240. The cutting zone 240 is only schematically depicted in Figs. 50 and 51. The cutting zone 240 may particularly include a plurality of wire guides adapted to span a wire web there between for sawing a semiconductor ingot, as exemplarily shown in Fig. ID.

[00487] According to embodiments, the cutting zone 240 may be a high tension zone in which the wire tension of the wire 11 is at least 15 N, particularly at least 20 N, more particularly 25 N. The wire spool zone 390 may, for example, be a low tension zone in which the wire tension of the wire 11 is at most 10 N, particularly at most 8 N, more particularly at most 5 N.

[00488] By circulation of the wire several times between the first guide roller and the second guide roller, the tension modifier is adapted to allow an amendment of the wire tension, when the wire is exiting the tension modifier, as compared to the wire tension of the wire entering the tension modifier. [00489] According to embodiments which can be combined with other embodiments described herein, the wire 11 may be wound at least 2 times around the first guide roller 315 and the second guide roller 325, particularly at least 5 times or 8 times. In embodiments, the wire is wound around the first and the second guide roller at most 30 or even at most 25 times. In embodiments, the wire may be wound around the first guide roller 315 and the second guide roller 325 less than 20, particularly less than 15 times.

[00490] According to embodiments which can be combined with other embodiments described herein, the wire tension in the cutting zone 240 may be regulated by rotating the first guide roller 315 together with the connection arm 35 around the axis of rotation 45 of the second guide roller 325. In embodiments, the connection arm 35 may engage at the axis of rotation 45 of the second guide roller 325. The distance between the first guide roller 315 and the second guide roller 325 may be determined by the length of the connection arm 35. Efficient adjusting may be obtained by guiding the wire into the first guide roller 315 so that the direction in which the wire is entering the first guide roller 315 is perpendicular to the connection arm 35. Additionally or alternatively, the wire exiting the first guide roller 315 may be guided so that the direction in which the wire is exiting the first guide roller 315 is perpendicular to the connection arm 35. Accordingly, the connecting arm can be considered as a pendulum arm in various embodiments disclosed herein.

[00491] According to embodiments which can be combined with other embodiments described herein, the wire saw system, particularly the wire management system, may include a sensing device for measuring at least one of the first wire tension and the second wire tension. Additionally or alternatively, a position sensor 56 may be provided for measuring the position and/or deflection of the second guide roller, as exemplarily shown in Fig. 50.

[00492] According to embodiments which can be combined with other embodiments described herein, the wire management system may include a first sensing device 28 being arranged in the wire spool zone 390 between the tension modifier 333 and the take-up spool 138. Additionally or alternatively, a second sensing device 29 can be arranged between the pulley 133 and the tension modifier 333. The second sensing device 29 may be adapted for measuring the wire tension of the wire 11 before or upon entering the tension modifier 333. The first sensing device 28 may be adapted for measuring the wire tension of the wire 11 upon or after exiting the tension modifier 333. [00493] According to embodiments which can be combined with other embodiments described herein, the first sensing device 28 and/or the second sensing device 10 may be disposed at a pulley 133 for guiding the wire 11. Further, the first sensing device 28 and/or the second sensing device 29 may include a force sensor for measuring the wire tension. For example, the speed of at least one of the first guide roller 315 and the second guide roller 325 may be adapted to the wire tension measured by the first sensing device 28 and/or the second sensing device 29. Additionally or alternatively, the speed of an actuated wire guide may be adapted to the wire tension measured by the first sensing device 28 and/or the second sensing device 29. Additionally or alternatively, the speed of the take-up spool 138 may be adapted to the wire tension measured by the first sensing device 28 and/or the second sensing device 29.

[00494] According to embodiments which can be combined with other embodiments described herein, the wire saw management system may include a controller 1330 for controlling the tension modifier 333 based on the measured wire tension data. The first sensing device 28 and/or the second sensing device 29 and/or the position sensor 56, may be connected to the controller 1330 via a cable or wireless. The data measured by at least one of the first sensing device 28 and/or the second sensing device 29 and/or the position sensor 56 may be fed back to the controller 1330. Based on the measured data, the controller 1330 may evaluate and calculate several parameters of the tension modifier 333 and control and regulate the tension modifier accordingly. The controller of the wire management system may be part of the electrical control system of the wire saw system as described herein.

[00495] According to embodiments, which can be combined with other embodiments described herein, a third sensing device may be disposed at the tension modifier 333, particularly at the connection arm 35, for controlling and regulating the wire tension in the cutting zone 240. The third sensing device may determine the actual torque of the connection arm 35 and the torque needed for a specific wire tension. Accordingly, the speed of an actuated wire guide and/ or the speed of the first guide rollers 315 and/ or the second guide roller 325 may be adjusted.

[00496] According to embodiments, which can be combined with other embodiments described herein, the connection arm 35 may be actuated by an actuator 316, as exemplarily shown in Fig. 50. The actuator may be an electric motor, such as a brushless motor, a servo motor, or a pneumatic motor. In particular, a linear actuator in combination with kinematic transformation into rotational movement may be employed.

[00497] With exemplary reference to Fig. 51, according to embodiments of the wire management system which can be combined with other embodiments described herein, the second guide roller may not be pivotable around the first guide roller. This may also be called "stiff connection" of the tension modifier herein. In particular, the axis of rotation 45 of the first guide roller 315 and the axis 61 of the second guide roller 325 may both be fixed in their position.

[00498] According to embodiments, the tension modifier includes one, optionally two guide rollers that each may be provided with a conically shaped body as described with respect to other embodiments herein. In particular, both the first guide roller and the second guide roller, may be provided with a conically shaped body.

[00499] In addition, in embodiments employing a stiff connection between the first guide roller and the second guide roller, a tension adjuster is provided. For instance, as depicted in the exemplary embodiment shown in 51, a tension adjuster 337 may be provided in the wire management system. Particularly, the tension adjuster 337 may be provided between the tension modifier 333 and the cutting zone 240, as exemplarily shown in Fig. 51. The tension adjuster may be configured to adjust the tension, in particular, to keep the tension as constant as possible for the cutting process in the cutting zone 240. Accordingly, the accuracy of the tension regulation in the cutting zone.

[00500] In further embodiments not specifically illustrated, the tension adjuster may be provided between the wire spool zone 390 and the tension modifier 333. Further, according to embodiments, which can be combined with other embodiments described herein a first tension adjuster may be provided between the tension modifier 333 and the cutting zone 240, and a second tension modifier may be provided between the wire spool zone 390 and the tension modifier 333.

[00501] As exemplarily shown in Fig. 51, according to embodiments of the wire management system which can be combined with other embodiments described herein, the tension adjuster may be provided with a center 17 of pivoting. Further, an arm 36 can be provided for a pulley 131 to pivot about. The pulley 131 may pivot passively, i.e. dependent on the tension difference of the wire at both sides of the guide roller. Alternatively, an actuator may be provided that actively controls the pivot movement of the pulley 131 about the center 17 of pivoting.

[00502] According to embodiments described herein, a wire saw system 1000 is provided which includes a tension modifier 333 adapted to convert a first wire tension into a second wire tension. The tension modifier includes a first guide roller 315 including an axis of rotation 45 and a plurality of grooves 155 being formed in an outer circumferential surface of the first guide roller 315. Further, the tension modifier includes a second guide roller 325 including a plurality of grooves 155 being formed in an outer circumferential surface of the second guide roller 325. The first guide roller 315 and the second guide roller 325 are spaced apart from each other at a fixed distance L.

[00503] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, the second guide roller 325 is pivotable around the axis of rotation 45 of the first guide roller 315. Preferably, the first guide roller 315 and the second guide roller 325 are connected through a connection arm 35.

[00504] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, the first guide roller 315 and the second guide roller 325 are connected through a connection arm, in particular with the axis of the first guide roller and the axis of the second guide roller being fixed in position.

[00505] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, the difference between the first wire tension and the second wire tension is at least 5N, optionally at least 10 N, optionally at least 15 N.

[00506] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, at least one of the first guide roller 315 and the second guide roller 325 have a cylindrically shaped body optionally with a diameter in the range of 10 cm and 25 cm, optionally between 15 cm and 20 cm. [00507] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein at least one of the first guide roller 315 and the second guide roller 325 is actuated by an actuator 316.

[00508] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, the wire saw system further includes at least one of a sensing device for measuring at least one of the first wire tension or the second wire tension, and a position sensor for measuring the position of the second guide roller 325.

[00509] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, the wire saw system further includes a controller 1330 for controlling the tension modifier 333 based on the measured wire tension data.

[00510] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, the plurality of grooves includes at most 30 grooves.

[00511] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, wherein the grooves have a pitch from the center of one groove to the center of an adjacent groove in the range of from 1 mm to 5 mm.

[00512] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, wherein at least one of the first wire tension is in the range of up to 10 N and the second wire tension is in the range of at least 15 N; and the second wire tension is in the range of up to 10 N and the first wire tension is in the range of at least 15 N.

[00513] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, at least one of the first guide roller 15 and the second guide roller 325 have a conically shaped body. Preferably, both the first guide roller and the second guide roller have a conically shaped body.

[00514] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, at least one of the first guide roller and the second guide roller has a first diameter on a first end 302 and a second diameter on a second end 303, wherein the first diameter is larger than the second diameter by at least 1 mm, optionally by at least 2 mm.

[00515] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, the diameter increases constantly in a longitudinal direction of the conically shaped body from the first end 302 to the second end 303.

[00516] According to embodiments of the wire saw system 1000, which can be combined with other embodiments described herein, at least one of the grooves 155 of the first guide roller 315 and the grooves 155 of the second guide roller 325 are arranged in parallel with the number of grooves in at least one of the first guide roller 315 and the second guide roller 325 preferably being at most 30 windings.

[00517] In the following, embodiments of a wire inspection system, particularly for a wire saw system as described herein are described.

[00518] As exemplarily shown in Fig. 34, according to embodiments of the wire saw system as described herein, the wire inspection system 700 may be arranged in the wire management system 1200.

[00519] According to embodiments which can be combined with other embodiments described herein, the wire inspection system includes a camera and a camera control unit. The camera control unit can be adapted for controlling the camera, for instance, by triggering when one or more pictures are taken by the camera. The camera or the camera control unit is particularly adapted for performing an image recognition algorithm for evaluating the imaged pictures. The wire inspection system may also be connected to actuators and devices to steer the electric motors which move the wire.

[00520] According to embodiments which can be combined with other embodiments described herein, the camera is positioned adjacent to the take-up spool. In this respect, the term "adjacent" is to be understood in that the camera is positioned at a wire's location after the sawing, for example inside the wire management system. As exemplarily shown in Fig. 34, after passing a camera of the wire saw control system, the wire might run over one or more pulleys or the like to the take-up spool 138.

[00521] According to embodiments of the wire saw control system, the operation of the camera and the operation of the wire can be synchronized. Accordingly, it is possible to inspect the wire at those times when the obtained picture quality is maximized. For example, the camera can be triggered to take a picture at times when the wire's speed is zero or substantially zero, particularly when the wire moves forwards and backwards in an alternating manner. The term "substantially zero" may include a speed of up to +/- 1 m/s. For example, the operation of the camera can be triggered when the moving direction of the wire is changed, for instance, from a forward movement to a backward movement, or from a backward movement to a forward movement.

[00522] According to embodiments which can be combined with other embodiments described herein, the camera takes one picture when its operation is triggered, according to other embodiments, the camera takes at least two, three or even more pictures when its operation is triggered. Alternatively, the camera may be adapted to take pictures constantly, such as at least 30 or 50 pictures per second (e.g., the camera may be a video camera).

[00523] According to embodiments of the wire saw control system, a plurality of the set pictures taken by a camera can be analyzed in order to inspect the wire. Alternatively, only one picture of the set of pictures is used for further analysis, for example the one picture that outperforms the other pictures in terms of picture quality such as contrast. Alternatively or additionally, the wire inspection system may include at least a second camera that may be adapted to take pictures of the wire at the same time as the first camera. It is possible that the pictures taken by the first camera and the pictures taken by the second camera are used for the analysis of the inspection.

[00524] According to embodiments of the wire inspection system as described herein the camera may be a video camera. According to some embodiments, only those pictures that were taken at a wire speed allowing appropriate result quality are analyzed. In other words, according to embodiments, the pictures that were taken at high speed might be disregarded whereas the picture(s) taken at a reduced speed or even zero speed of the wire is/are analyzed. [00525] In the present disclosure, "inspection of the wire" may be understood as an analysis of wire parameters such as the wire diameter and/or wire homogeneity, i.e., variation in the diameter.

[00526] According to embodiments, which can be combined with other embodiments described herein, threshold values for wire parameters may be defined that can be stored in a data storage unit, which may be part of or associated with the wire saw control system. Further, the wire inspection system may be adapted for comparing the measured values of the wire parameters with the stored threshold values. In dependence of the comparison result, an action may be triggered.

[00527] For example, a set of threshold values may be defined including, for example, a first threshold value, and a second threshold value. The threshold values may refer to the wire's diameter and thus indicate the wire's wear.

[00528] According to embodiments which can be combined with other embodiments described herein, the first threshold value may define a first diameter wherein underrunning this first diameter may cause the operation of the wire saw system to switch to a first operation mode. The first operation mode may include a higher speed of the wire than under normal operation. Furthermore, the first operation mode may include a speed of the wire that can be smaller than the speed as under the second operation mode. For instance, the speed of the first operation mode may be increased by at least 3% or by at least 6% as compared to normal operation. Alternatively or additionally, the first and second operation mode may include a larger ratio between the forth movement and the back movement of the wire as compared to normal operation.

[00529] According to embodiments which can be combined with other embodiments described herein, the second threshold value may define a second diameter wherein underrunning this second diameter causes the operation of the wire saw to switch to a second operation mode. The second operation mode may include a higher speed of the wire than under normal operation. The term "normal operation" may be understood as an operation mode wherein the wire saw is operated at a speed as intended and not influenced by the underrun of any threshold value. For instance, the speed of the second operation mode may be increased by at least 5% or at least 10% as compared to normal operation. [00530] According to embodiments which can be combined with other embodiments described herein, a function relating to an operation parameter of the wire saw system may be defined for triggering a reaction, for example the wire speed as a function to one or more measured wire parameter(s), such as the wire diameter. For example, let d be the measured wire's diameter, and let v be the speed with which the wire saw is operated, then the wire saw is operated with a speed that is a function of the wire's diameter, that is, according to v = f(d). For example, the function f(d) can be a steadily decreasing function, for instance, v may be inversely proportional to d. Accordingly, these exemplary relations may relate to situations above the minimum speed with which the wire saw can be operated.

[00531] According to embodiments which can be combined with other embodiments described herein, the operation of the camera may be synchronized with the movement of the wire. For example, the camera may be synchronized with the back-and-forth of the wire or with different wire speeds for specific time intervals in one direction. For example, the wire may be moved with a first speed. The first speed may be the maximum speed of the wire saw. After a selectable time interval, the wire's speed can be reduced to a lower speed value to take a picture of the wire. The lower speed may be between (including) zero and (excluding) the maximum speed. For instance, the maximum speed may be in the range of between 15 and 25 m/s, and the lower speed for taking a picture may be in the range of between 0 and 10 m/s, particularly between 0 and 5 m/s. After taking the picture, the wire's speed may be increased again, for example to the maximum speed.

[00532] According to embodiments, the camera is additionally provided with one or more of the features discussed in the following with exemplary reference to Fig. 52. A laser shadowing device may be provided that is, according to specific embodiments, positioned at or inside a wire saw. It may include protections in order to avoid damages or malfunctions such as caused by, e.g., slurry splashing or the like.

[00533] With exemplary reference to Fig. 52, a wire inspection system according to embodiments described herein is described. According to embodiments of the wire inspection system which can be combined with other embodiments described herein, the wire inspection system may include a laser shadowing device 680. The laser shadowing device can be arranged for inspection of the wire 11. For example, the wire 11 can be accommodated in a recess 690 of the laser shadowing device. The wire shadowing device may include a rotatable mirror 625. On a small scale, the rotatable mirror may include a plurality of planar plates. Accordingly, the reflection direction of the mirror may alternate constantly when the mirror pivots.

[00534] Further, the laser shadowing device 680 may include a light source, for example a laser diode 640 for generating a beam 650 of laser light. The beam of laser light may be directed at the rotatable mirror 625. The rotatable mirror may reflect the beam 650 in an alternating manner to a first mirror 610 and a second mirror 611. Fig. 52 shows an example in which the beam 650 is reflected towards the first mirror 610. As exemplarily shown in Fig. 52, the first mirror 610 and the second mirror 611 may reflect the beam through further optional optical devices such as a first lens 630 and a second lens 631, respectively, as well as through a third lens 670 and a fourth lens 671, respectively. Accordingly, the wire 11 may be encircled by the measuring laser beam from both sides in an alternating manner. The laser beam can be registered in a first camera 621 and a second camera 622. The first camera 621 and the second camera 622 can be cameras as described herein; in particular, the first camera 621 and the second camera 622 can be photodiodes. The first camera 621 and the second camera 622 may be connected to a signal processing unit 660 adapted for evaluating the measurement results. The camera control unit as described herein can act as the video signal processing unit.

[00535] According to embodiments which can be combined with other embodiments described herein, the signal processing unit 660 and/or the camera control unit may be part of the electrical control system of the wire saw system as described herein.

[00536] According to embodiments which can be combined with other embodiments described herein, a wire inspection system 380 for operating a wire saw system 1000 as described herein is provided. The wire inspection system 380 includes: a camera for inspecting the wire, and a camera control unit for operating the camera dependent on the wire speed.

[00537] According to embodiments which can be combined with other embodiments described herein, the wire saw control is adapted for amending at least one operation parameter of the wire saw system 1000 in dependence of the outcome of the inspection, wherein the at least one operation parameter is optionally chosen as one or more of the following group: increasing the wire speed, reducing the table speed, and increasing the ratio between forward movement and backward movement.

[00538] According to embodiments which can be combined with other embodiments described herein, inspecting the wire includes inspecting one or more of the following properties: wire wearing, wire diameter, wire homogeneity, diamond concentration of the wire and diamond repartition of the wire.

[00539] According to embodiments which can be combined with other embodiments described herein, the wire saw system may include one or more wire saw control systems as described herein.

[00540] According to embodiments which can be combined with other embodiments described herein, the camera of the wire inspection system is positioned adjacent to the take- up spool 138.

[00541] According to embodiments which can be combined with other embodiments described herein, a method for inspecting a wire of a wire saw system as described herein is provided. The method for inspecting a wire includes: moving the wire with a variable wire speed, inspecting the wire in dependence of the wire speed, and obtaining an inspection result.

[00542] According to embodiments of the method for inspecting a wire which can be combined with other embodiments described herein, inspecting the wire includes taking at least one picture of the wire with a camera.

[00543] According to embodiments of the method for inspecting a wire which can be combined with other embodiments described herein, inspecting the wire includes inspecting one or more of the following properties: wire wearing, wire quality, wire diameter, wire homogeneity, diamond concentration of the wire and diamond repartition of the wire.

[00544] According to embodiments which can be combined with other embodiments described herein, a method for operating a wire saw system as described herein is provided. The method for operating a wire saw system includes the method for inspecting the wire according to embodiments described herein. [00545] According to embodiments which can be combined with other embodiments described herein, the method for operating a wire saw system includes moving the wire in a first direction for a first time interval, and moving the wire in a second direction for a second time interval, wherein the first and the second directions are opposite to each other.

[00546] According to embodiments of the method for operating the wire saw system which can be combined with other embodiments described herein, the second time interval is smaller than the first time interval.

[00547] According to embodiments of the method for operating the wire saw system which can be combined with other embodiments described herein, the wire is inspected when the wire speed is substantially zero.

[00548] According to embodiments which can be combined with other embodiments described herein, the method for operating the wire saw system further includes changing at least one operating parameter of the wire saw system dependent on the inspection result, wherein the at least one operation parameter is optionally chosen as one or more of the following group: increasing the wire speed, reducing the table speed, and increasing the ratio between forward movement and backward movement.

[00549] With exemplary reference to Fig. 53 showing a block diagram for illustrating a method for cutting semiconductor material, embodiments of the method for cutting semiconductor material are described in the following.

[00550] According to embodiments, which may be combined with other embodiments described herein, the method 2000 for cutting semiconductor material includes: loading 2001 an ingot of semiconductor material into a wire saw system, urging 2002 the ingot against a wire web, and moving 2003 the wire web relative to the ingot.

[00551] According to embodiments of the method 2000 for cutting semiconductor material, which may be combined with other embodiments described herein, loading 2001 an ingot includes using an ingot loader 1600, for example an ingot loader as exemplarily shown in Fig. 1C.

[00552] According to embodiments of the method 2000 for cutting semiconductor material, which may be combined with other embodiments described herein, urging 2002 the ingot against the wire web includes an alternating movement of the ingot, in particular a rocking movement of the ingot, particularly by means of an ingot feeding system. In particular, urging 2002 the ingot against the wire web may be performed by using an ingot feeding system 300 according to embodiments described herein.

[00553] According to embodiments of the method 2000 for cutting semiconductor material, which may be combined with other embodiments described herein, urging 2002 may include the method for feeding an ingot during cutting according to embodiments described herein.

[00554] Further, according to embodiments, which may be combined with other embodiments described herein, the method 2000 for cutting semiconductor material may include the method for monitoring a wire bow in a wire saw system according to embodiments as describe herein.

[00555] Further, according to embodiments, which may be combined with other embodiments described herein, the method 2000 for cutting semiconductor material may include the method for monitoring physical characteristics of at least one wire according to embodiments described herein.

[00556] Further, according to embodiments, which may be combined with other embodiments described herein, the method 2000 for cutting semiconductor material may include the method for measuring the operation condition of a wire saw system according to embodiments described herein.

[00557] Further, according to embodiments, which may be combined with other embodiments described herein, the method 2000 for cutting semiconductor material may include the method for inspecting a wire of a wire saw system as described herein.

[00558] According to embodiments of the method 2000 for cutting semiconductor material, which may be combined with other embodiments described herein, moving 2003 the wire web relative to the ingot includes a back-and-forth movement of the wire as described herein.

[00559] According to embodiments of the method 2000 for cutting semiconductor material, which may be combined with other embodiments described herein, a wire saw system 1000 according to embodiments described herein is employed for carrying out the method 2000 for cutting semiconductor.