CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application Serial No. 62/239,594, filed 09 October 2015, the disclosure of which is hereby incorporated by reference in its entirety.

FIELD

[0002] This disclosure relates generally to slicing semiconductor wafers from an ingot using a wire saw and more particularly to modifying an existing wire saw.

BACKGROUND

[0003] Semiconductor wafers are commonly used in the production of integrated circuit (IC) chips on which circuitry are printed. The circuitry is first printed in miniaturized form onto surfaces of the wafers. The wafers are then broken into circuit chips.

[0004] To create semiconductor wafers, a silicon ingot is typically prepared using the Czochralski method during which a seed crystal is brought into contact with molten silicon, and then a single crystal is grown by slow extraction resulting in the silicon ingot. Individual wafers are sliced or cut from the ingot. This may be done using an inner-diameter saw or wire saw. In the case of a wire saw, the ingot is brought into contact with a cutting web of fast moving wire. The cutting web is formed by feeding a single wire from one spool to another and passing the wire across two or more drums multiple times to form the cutting web. Each pass of the wire allows an

additional wafer to be cut from the silicon ingot in a single cutting operation as the silicon ingot is brought into contact with the cutting web.

[0005] The wire slices or cuts wafers from the ingot using an abrasive material. A standard wire saw uses a loose abrasive (e.g., "slurry") that is carried by the wire to cut the silicon ingot. The slurry is applied to the wire as it travels through the cutting web and the abrasive material combined with the motion of the wire slices or cuts the silicon ingot as it is brought into contact with and/or at least partially passed through the cutting web. Material that is removed from the silicon ingot during the slicing process but which does not form a part of the produced wafers is waste material (e.g., silicon "kerf") . A reduction in kerf (e.g., reducing "kerf loss") increases the efficiency of the wafer slicing process and allows for a greater number of wafers to be cut from a silicon ingot. At least some standard wire saws produce less kerf than wafer slicing conducted by an inner- diameter saw, as the diameter of the wire is less than the thickness of a typical inner-diameter saw blade.

[0006] Some known wire saws use a fixed abrasive material that forms a part of or is carried by the wire instead of a loose abrasive that is sprayed onto the wire and/or workpiece temporarily. The fixed abrasive provides the cutting action which slices the wafers from the silicon ingot. The fixed abrasive material may be diamond, in which case, the wire saw uses diamond coated wire (DCW) . Typically, a diamond impregnates the wire or is otherwise attached to or carried by the wire. DCW generally has a diameter smaller than wire used in a standard wire saw in combination with slurry. The smaller diameter of DCW results in decreased kerf loss in

comparison to standard wire that does not include a fixed abrasive. However, the smaller diameter of DCW causes DCW to be more prone to breaking as compared to larger diameter standard wire. A standard wire saw is not well suited to using DCW in place of standard wire, as the configuration of a standard wire saw is not designed for thinner DCW. Running DCW in a standard wire saw may result in frequent breakage of the DCW.

[0007] This Background section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure.

Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art .

SUMMARY

[0008] An aspect is directed to a method of retrofitting an existing wire saw from one that uses loose abrasive to one that uses a fixed abrasive wire. The method includes removing an existing wire spool traverser and installing a replacement new wire spool traverser including two guide rollers connected to at least one load cell that measures strain on the two guide rollers caused by a wire passing between the two guide rollers. The method further includes installing a wire positioning system configured to position the wire away from a shoulder of at least one existing directional pulley of the existing wire saw.

[0009] According to another aspect, a system for retrofitting an existing wire saw from one that uses loose abrasive to one that uses a fixed abrasive wire includes a replacement new wire spool traverser including two guide rollers coupled to at least one load cell that measures strain on the two guide rollers caused by a wire passing between the two guide rollers. The system further includes a wire positioning system that positions the wire away from a shoulder of at least one existing directional pulley of the existing wire saw.

[0010] According to another aspect, a standard wire saw designed for use with a loose abrasive is modified for use with a fixed abrasive wire and includes a

replacement new wire spool traverser, a first existing directional pulley, and a wire positioning system. The replacement new wire spool traverser includes two guide rollers coupled to at least one load cell that measures strain on the two guide rollers caused by a wire passing between the two guide rollers. The wire positioning system positions the wire away from a shoulder of the first existing directional pulley of the modified standard wire saw.

[0011] Various refinements exist of the features noted in relation to the above-mentioned aspects. Further features may also be incorporated in the above- mentioned aspects as well. These refinements and

additional features may exist individually or in any combination. For instance, various features discussed below in relation to any of the illustrated embodiments may be incorporated into any of the above -described aspects, alone or in any combination.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a schematic illustration of a standard wire saw using a loose abrasive.

[0013] FIG. 2 is a schematic illustration of a wire management system of a standard wire saw using a loose abrasive .

[0014] FIG. 3 is schematic illustration of the wire management system shown in FIG. 2 modified for use with diamond coated wire (DCW) , according to one

embodiment .

[0015] FIG. 4A is a top view of the traverser, shown in FIG. 3, for modifying the wire management system shown in FIG. 2 for use with DCW.

[0016] FIG. 4B is a front elevation view of the traverser, shown in FIG. 3, for modifying the wire management system shown in FIG. 2 for use with DCW.

[0017] FIG. 4C is a side elevation view of the traverser, shown in FIG. 3, for modifying the wire

management system shown in FIG. 2 for use with DCW.

[0018] FIG. 5A is a schematic illustration of the wire management system shown in FIG. 2 modified for use with DCW, according to an alternative embodiment.

[0019] FIG. 5B is a schematic side elevation view of a portion of the modified wire management system shown in FIG. 5A. [0020] FIG. 6 is a flow chart illustrating a method for modifying an existing standard wire saw for use with DCW.

[0021] FIG. 7 is a block diagram illustrating components of a control system of the modified wire saw shown in FIGS. 3 and 5A.

[0022] FIG. 8 is a schematic illustration of the wire management system shown in FIG. 2 modified for use with DCW, according to an alternative embodiment.

[0023] Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

[0024] Generally, and in some embodiments, an existing standard wire saw uses a first wire in combination with a loose abrasive (e.g., a slurry) to slice wafers from a silicon ingot. The existing standard wire saw may be modified using one or more components, systems, and/or methods described herein. The existing standard wire saw is modified for use with a second wire that is diamond coated wire ("DCW") . The modification makes the existing standard wire saw suitable for DCW by reducing the

likelihood of the DCW breaking because of its smaller diameter in comparison to the standard wire for which the existing saw was designed. Although standard wire saws and standard wires saws modified to use DCW are generally described and/or shown herein in a horizontal lay-out, in some embodiments, the saws and modified saws have a vertical lay-out. Alternatively, the saws may have any other suitable layout. [0025] Modifying the existing standard wire saw may include one or more of installing a replacement traverser, bypassing a roller, installing a wire

positioning system, installing a replacement new wire spool, and/or installing a replacement used wire spool. In some embodiments, a replacement traverser is installed to wind and/or unwind wire from one or more of a new wire spool, supplying wire to the wire saw, and a used wire spool, receiving wire fed from the new wire spool. The replacement traverser facilitates use of DCW with the modified saw. For example, the replacement traverser includes two guide rollers which center the DCW on a pulley of the traverser to mitigate hang ups on the pulley shoulder. The two guide rollers are further connected to a load cell that provides input to a control system in order to positon the traverser such that the DCW is unwound from the spool and/or wound onto the spool perpendicularly from the axis of rotation of the spool. The traverser may be positioned to bypass a roller of the existing saw which reduces stress on the DCW. The wire positioning system positions the DCW such that the DCW is centered between the shoulders of one or more pulleys of the saw. This

mitigates hang ups of the DCW on the pulley shoulders, reducing stress on the DCW, and prevents the DCW from jumping a pulley shoulder. In some embodiments, the wire positioning system includes pairs of rollers positioned, in relationship to a pulley, to center the DCW between the shoulders of the pulley. In some embodiments, the wire positioning system includes three pulleys with two pulleys aligning the DCW with pulleys of the wire saw and the third pulley tensioning the DCW. The two pulleys of the wire positioning system center the DCW between the shoulders of the pulleys of the saw and the third pulley maintains the DCW in contact with the two pulleys of the wire positioning system. A replacement new wire spool and/or a replacement used wire spool may be installed which are configured for use with DCW rather than standard wire.

[0026] Prior to modification, the existing wire includes a new wire spool traverser that winds standard wire onto a new wire spool when the wire saw is run in a backward winding mode. A roller is positioned between new wire spool and the new wire spool traverser. The existing wire saw includes a plurality of directional pulleys that feed the standard wire to the cutting web and onto a used wire spool. The directional pulleys change the path of the wire which enters the directional pulley at a first angle, wraps partially around the directional pulley, and exits the pulley at a second angle. The existing wire saw further includes directional pulleys included on tensioners that tension the standard wire.

[0027] After modification for use with DCW, the wire saw does not include a roller positioned between the new wire spool and a traverser. The modified wire saw includes a replacement new wire spool traverser that replaces the existing traverser. The wire saw further includes a wire positioning system after modification. In one embodiment, the wire management system includes at least one pair of rollers positioned relative to a

direction pulley such that the DCW is positioned away from the shoulders of the directional pulley. In an alternative embodiment, the wire management system includes three support pulleys. The three support pulleys are positioned to prevent the DCW from contacting the shoulders of a directional pulley. One of the support pulleys is placed in a different plane relative to the other two support pulleys to tension the DCW.

[0028] The modifications to the existing wire saw include removing one or more components and altering the manner in which wire is unwound from one or more spools and/or wound onto one or more spools. Replacement

traversers can wind/unwind for the entire length of the spool and/or have controlled movement that keeps the wire perpendicular to the spool during winding/unwinding to reduce stress on the DCW. The modifications further include guiding the DCW with a wire positing system to avoid stress caused by the DCW coming into contact with the shoulders of pulleys designed for use with standard wire.

[0029] Modification of the existing standard wire saw includes removing one or more existing components such as a traverser. The existing traverser may not have a sufficient stroke to wind wire along the entire length of a wire spool. This may cause wire accumulations that, while not damaging to standard wire, damage DCW. A replacement traverser is installed. The replacement traverser has a greater stroke length than that of the existing traverser. This allows the replacement traverser to wind/unwind the DCW along the entirety of a spool preventing accumulation of the DCW in one area and possible resulting breakage. A wire positioning system is installed as part of the modification. The wire positioning system reduces or prevents the DCW from contacting shoulders of one or more existing pulleys of the standard wire saw which are retained. The reduced or eliminated shoulder contact prolongs the life of the DCW by reducing or eliminating stress on the DCW caused by contact (e.g., hang ups) with the pulley shoulder. The reduced or eliminated shoulder hang ups also prevents the DCW from escaping the pulley and becoming unthreaded.

[0030] More specifically, the wire management system of the existing standard wire saw may be modified. In some embodiments, the existing standard wire saw is modified, at least in part, by replacing an existing wire traverser configured to feed and/or unwind a new wire spool with a replacement new wire spool traverser. The

replacement traverser includes one or more of guide rollers, a pulley rotated 90 degrees in comparison to a pulley of the existing wire traverser, and/or an encoder. In some embodiments, the stroke of the replacement

traverser is greater than that of the existing wire traverser. This allows the replacement new wire spool traverser to wind and/or unwind wire to and/or from the new wire spool along the entire length of the new wire spool. In some embodiments, the replacement of the traverser includes at least one load cell connected to the two guide rollers. The load cell is used by a control system to control the movement of the traverser based on which of the two guide rollers in under load from the DCW passing between them. The control system causes the replacement traverser to move to reduce the load (e.g., measured as strain) on the guide rollers. The control system may be added to the existing standard wire saw and/or programmed to control the replacement traverser as described herein. In some alternative embodiments, the standard wire saw includes an existing control system that is programmed or reprogrammed to control the replacement traverser. [0031] In some embodiments, the existing standard wire saw is modified, at least in part, by installing a wire positioning system. The wire positioning system reduces the likelihood of DCW breakage. The wire positioning system prevents hang up of the DCW on one or more pulley shoulders of the wire management system. In some embodiments, the wire positioning system includes at least a first pair of rollers that are positioned to align the DCW with a pulley included in the replacement traverser (e.g., centering the DCW on the pulley to prevent the DCW from contacting the shoulder of the pulley) . In some embodiments, the wire positioning system includes

additional pairs of rollers that align the DCW with other components of the modified wire saw (e.g., directional pulleys, tensioner pulleys, an existing take up traverser associated with a used wire spool, a replacement take up traverser, and/or other components) .

[0032] In some embodiments, the wire positioning system includes at least one set of three support pulleys. All three support pulleys rotate about axes that are 90 degrees from the axes of rotation of other components for which the support pulleys align the DCW. The second pulley is mounted in a first plane parallel with the axes of rotation of the support pulleys, with the first and third support pulleys being mounted at least a second plane parallel with the axes of rotation of the support pulleys. The first plane is at a lower elevation than the second plane. The DCW path travels over the first and third support pulleys with the first and third pulleys being positioned such that the radius of the pulleys aligns with pulleys for which the first and third support pulleys align the DCW (e.g., the radius of the first and third support pulleys terminates at or near a point equidistant from the shoulders of the pulley for which the DCW is aligned) . The DCW path travels under the second support pulley such that the second support pulley tensions the DCW and maintains the DCW in contact with the first and third support pulleys that position/align the DCW path with pulleys of other components of the modified wire saw (e.g., directional pulleys, tensioner pulleys, an existing take up traverser associated with a used wire spool, a replacement take up traverser, and/or other components) .

[0033] Referring now to FIG. 1, a standard wire saw including a wire management system 100 and a cutting web 102 is illustrated according to an exemplary embodiment. A new wire spool 112 initially holds a wire 110 that is used to from cutting web 102 for slicing wafers from an ingot 104 (e.g., a silicon ingot) . Wire 110 is threaded from new wire spool 112 through wire management system 100 and cutting web 102 to a used wire spool 114. The moving wire 110 and loose abrasive (e.g., slurry; not shown) applied to wire 110 with one or more slurry nozzles 108 provides the cutting action which slices wafers from ingot 104. Ingot 104 is brought into contact with wire 110 wound around rollers 106. Each pass of wire 110 around rollers 106 cuts ingot 104 to form wafers. In some operations, wire 110 is wound from used wire spool 114 back to new wire spool 112 to perform additional cutting.

Multiple iterations of a forward winding leg (e.g., from new wire spool 112 to used wire spool 114) and a backward winding leg (e.g., from used wire spool 114 to new wire spool 112) may be used to perform multiple cuts. [0034] Cutting web 102 includes two rollers 106. In alternative embodiments, different numbers of rollers 106 are included in cutting web 102. For example, wire 110 may be wound around four rollers 106 to form cutting web 102. Cutting web 102 is fed with slurry from two sets of slurry nozzles 108. In alternative

embodiments, other numbers of slurry nozzles 108 are used to provide loose abrasive to cutting web 102. Wire management system 100 may have a variety of configurations for winding wire from new wire spool 112 through cutting web 102 and onto used wire spool 114 and/or from used wire spool 114 through cutting web 102 and onto new wire spool 112. Wire management system 100 uses one or more of a variety of components for winding wire 110, tensioning wire 110, measuring usage of wire 110, and/or otherwise managing wire 110. For example, wire management system 100 may include directional pulleys, traversers, tensioners, encoders, and/or other components for the management of wire 110 and the cutting of ingot 104 using cutting web 102.

[0035] Wire management system 100 of a typical standard wire saw uses wire 110 with a larger diameter than DCW. For example, wire 110 has a diameter of 140

micrometers or more in some cases. DCW typically has a core diameter of 120 micrometers or less. The larger diameter of wire 110 in a typical standard wire saw allows for the use of less precise control of wire 110 by wire management system 100 in comparison to wire saws using DCW. The larger diameter of wire 110 gives wire 110 more durability, and wire 100 in a standard wire saw is less susceptible to breakage in comparison to DCW used in the same wire saw. As a result, wire management system 100 may not be suitable for use with DCW while achieving low breakage rates. For example, an unmodified standard saw using DCW in place of standard wire may have breakage rates between around seven to eight percent. In contrast, a wire saw designed for use with DCW has a breakage rate of around zero percent in some cases. Modification of the standard wire saw as described herein may decrease breakage rates of DCW below seven to eight percent.

[0036] The increased breakage rates of a standard wire saw using DCW can result from stress on the less durable DCW. For example, wire management system 100 of a standard wire saw may not provide for

winding/unwinding, by a traverser, of new wire spool 112 and/or used wire spool 114 along the entire height of the spool. Pulleys of wire management system 100 may not be aligned, which may subject wire 110 to turns twists, bending, contact with pulley shoulders, and/or other forces. Given the larger diameter of standard wire 110, these forces are unlikely to result in breakage of wire 110. However, these forces result in increased breakage rates when DCW is used in place of wire 110 due to

decreased diameter, decreased durability, and/or increased brittleness (e.g., as byproduct of diamond plating or stress introduced into the DCW during plating) of DCW in comparison to standard wire 110. The mechanical resistance of DCW is much less than that of standard wire 110 in some cases. DCW may have a reduced breaking load in comparison to standard wire 110.

[0037] In some embodiments, wire management system 100 of a standard wire saw calculates wire 110 usage imprecisely when used with DCW. For example, wire management system 100 calculates wire usage and/or the amount of wire per winding cycle within approximately 2% of actual wire use in some cases. In a standard, slurry wire unwinding cycle (e.g., unwinding from new wire spool 112 onto used wire spool 114) , 500 meters of wire is unwound and usage may be calculated by wire management system 100 to be between 490 and 510 meters. In a typical winding cycle for the same slurry wire (e.g., unwinding from used wire spool 114 back onto new wire spool 112) , 350 meters of wire is wound and wire usage may be calculated to be between 343 and 357 meters. In a typical unwinding cycle using DCW, 1200 meters is unwound and usage may be

calculated to be between 1176 and 1224 meters. In a typical winding cycle using DCW, 1190 meters of wire is wound and wire usage may be calculated to be between 1166 and 1214 meters. Inaccuracy in calculating wire usage for DCW is more important than in slurry/loose abrasive wire cycles, because of the forward and backward cycles used with DCW have a smaller difference in length than the cycles used with loose abrasive wire. A standard wire saw using loose abrasive may use 60 kilometers of wire across multiple cycles to slice ingot 104 where a wire saw using DCW may use 1 kilometer of wire across multiple cycles to slice ingot 104. The longer cycles used in wire saws using DCW results in an increased importance in wire usage

calculation. If the error in wire usage calculation is greater than the difference between forward and backward winding cycles, real wire usage can be double, or more, than the calculated wire usage. Additionally, if the forward winding leg is shorter than the backward winding leg, this may drastically reduce wire usage by causing one portion of the DCW to be used more frequently than other portions, concentrating cutting wear. These results of wire usage calculation error impact wafer quality and/or wire usage amounts. Modifications to wire management system 100 as described herein result in increased wire usage calculation accuracy to allow for the use of DCW in place of standard wire 110. In some embodiments,

modification of wire management system 100 as described herein increases the accuracy of wire usage calculation, with the calculation being accurate to within approximately 100 meters pre modification to approximately to the calculation being accurate to within one meter after modification .

[0038] Referring now to FIG. 2, wire management system 100 of the standard wire saw shown in FIG. 1 is illustrated according to one embodiment. In other non- illustrated embodiments, wire management system 100 may include more, fewer, and/or different components or combinations of components. Wire management system 100 may further have alternative layouts in alternative

embodiments .

[0039] Wire management system 100 of a standard wire saw includes a new wire spool 112, a roller 216, a traverser 218, a pulley 220, and a pulley 222 on a new wire spool 112 side of cutting web 102. In a forward winding leg, as illustrated, wire 110 is fed from new wire spool 112, across intervening components, through cutting web 102, and onto a used wire spool 114. In a backward winding leg, wire 110 travels in the opposite direction of that illustrated. During the forward winding leg, wire 110 unspools from new wire spool 112 and passes around roller 216. Roller 216 acts as a bridge for a first pulley included in traverser 218. Traverser 218 includes a pulley (not shown) that is oriented vertically (e.g., rotates about an axis perpendicular to the illustrated Z-axis) . Traverser 218 moves vertically along the Z-axis to unwind (e.g., during a forward winding leg) and/or wind (e.g., during a backward winding leg) wire 110 from/to new wire spool 112. Wire 110 travels along roller 216 in the Z-axis direction as traverser 218 moves in the Z-axis direction to control the winding/unwinding of new wire spool 112. In some embodiments, existing wire spool traverser 218 does not unwind new wire spool 112 during forward winding, but rather remains stationary along the Z-axis. The winding of new wire spool 112 by the manufacturer of new wire spool 112 is trusted to provide for unwinding during, at least the first, forward winding cycle. New wire spool traverser 218 rewinds new wire spool 112 during a backward winding leg following a forward winding leg. Traverser 218 moves along the Z-axis to rewind wire 110 onto new wire spool 112 from used wire spool 114.

[0040] In the forward cycle, wire 110 exits traverser 218 and passes across pulley 220. Pulley 220 is a directional pulley that changes a direction in which wire 110 travels. For example and as illustrated, wire 110 passes across pulley 220 and exits pulley 220 in a

different direction within the X-Y plane. Pulley 220 positions wire 110 such that it is fed across an additional component of wire management system 100 (e.g., pulley 222) . In some embodiments, pulley 220 has additional or

alternative functions. For example, pulley 220 may be a tensioner, wire 110 support element, and/or other component or associated with another component. In some embodiments, pulley 220 is oriented horizontally (e.g., rotates about an axis parallel to the illustrated Z-axis) . In alternative embodiments, pulley 220 is oriented vertically (e.g., rotates about an axis perpendicular to the Z-axis) .

[0041] Continuing the forward leg, wire 110 exiting pulley 220 passes across pulley 222. Wire 110 exits pulley 222 and travels to cutting web 102. In some embodiments, pulley 222, is or forms part of, a tensioner. The tensioner including pulley 222 exerts force on wire 110 to maintain tension in wire 110 which in turn may assist in positioning wire 110 within/relative to other components of wire management system 100 and/or cutting web 102. For example, pulley 222 may be mounted at one end of an armature that pivots about the opposite end. The armature may be spring loaded and/or have a controllable position (e.g., be driven by a stepper motor or otherwise be positionable) . The armature causes pulley 222 to exert force against wire 110 and tension wire 110. Pulley 222 is oriented horizontally (e.g., rotates about an axis parallel to the illustrated Z-axis) . In alternative embodiments, pulley 222 is oriented vertically (e.g., rotates about an axis perpendicular to the Z-axis) . In some embodiments, pulley 220 has additional or alternative functions. For example, pulley 220 may be a directional pulley(e.g., a pulley where wire 110 contacts the pulley at a first angle in one plane and leaves the pulley at a second different angle in the same plane), wire 110 support element, and/or other component or associated with another component.

[0042] The used wire side of wire management system 100 includes a pulley 224, a pulley 226, a pulley 228, and used wire spool 114 on a used wire spool 114 side of cutting web 102. In a forward winding leg, as illustrated, wire 110 is fed from cutting web 102, across intervening components, and onto used wire spool 114. In a backward winding leg, wire 110 travels in the opposite direction of that illustrated.

[0043] In the forward winding leg, wire 110 exits cutting web 102 and passes across pulley 224. In some embodiments, pulley 224 is, or forms part of, a tensioner. The tensioner including pulley 224 exerts force on wire 110 to maintain tension in wire 110 which in turn positions wire 110 within/relative to other components of wire management system 100 and/or cutting web 102. Pulley 224 may be included in a similar or identical tensioner to that attached to pulley 222. Pulley 224 is oriented horizontally (e.g., rotates about an axis parallel to the illustrated Z-axis) . In alternative embodiments, pulley 224 is oriented vertically (e.g., rotates about an axis perpendicular to the Z-axis) .

[0044] Continuing the forward winding leg, wire 110 exits pulley 224 and passes across pulley 226. Pulley 226 is a directional pulley. In some embodiments, pulley 226 has additional or alternative functions. For example, pulley 226 may be a tensioner, wire 110 support element, and/or other component or associated with another component. Pulley 226 is oriented horizontally (e.g., rotates about an axis parallel to the illustrated Z-axis) . In alternative embodiments, pulley 226 is oriented

vertically (e.g., rotates about an axis perpendicular to the Z-axis) .

[0045] Wire 110 exits pulley 226 and passes across pulley 228 Pulley 228 is a directional pulley. In some embodiments, pulley 228 has additional or alternative functions. For example, pulley 228 may be a tensioner, wire 110 support element, and/or other component or associated with another component. In an embodiment, pulley 228 forms a portion of a take up traverser that winds used wire spool 114 during forward winding from new wire spool 112 to used wire spool 114. The traverser may also unwind used wire spool 114 during a backward winding leg. Pulley 226 is oriented horizontally (e.g., rotates about an axis parallel to the illustrated Z-axis) . In alternative embodiments, pulley 226 is oriented vertically (e.g., rotates about an axis perpendicular to the Z-axis).

[0046] The wire management system 100 of the existing standard wire saw includes a control system 276. Control system 276 controls the winding and unwinding of wire 110. For example, control system 276 may be or include a programmable logic controller that controls one or more components of the wire saw. Control system 276 controls components of wire management system 100. For example, control system 276 may control one or more motors that drive new wire spool 112 and/or used wire spool 114 to wind and/or unwind wire 110 from either spool. Control system 276 may control one or more tensioners. Control system 276 may control one or more traversers (e.g., traverser 218) . In some embodiments, control system 276 receives inputs from one or more sensors and controls wire management system 100 in response to the received inputs. For example, control system 276 receives inputs from one or more limit switches, position sensors, and/or other sensors that measure the position of a traverser. Control system 276 controls the position of the traverser in response to the sensor input (e.g., reverse a direction of a motor driving the traverser in response to determining that the traverser has reached a limit of travel and/or the end of a spool) . In some embodiments, control system 276 calculates wire usage. For example, control system 276 may calculate the amount (e.g., length) of wire that has been unspooled based on an amount of elapsed time and a rate at which a spool is being driven. In alternative embodiments, wire management system 100 of the existing standard wire saw does not include a control system.

[0047] Referring now to FIG. 3, wire management system 300 is illustrated following modification of wire management system 100 of an existing standard wire saw. The existing components of wire management system 100 of the existing standard wire saw are bypassed, replaced, and/or modified as part of modifying management system 100 of an existing standard wire saw for use with DCW post modification. Parts retained during the modification are indicated using reference numbers corresponding to the parts shown in FIG. 2.

[0048] Existing wire spool 112 and existing used wire spool 114 are replaced. A new wire spool 312 designed for DCW 310 and/or containing DCW 310 is used in place of the existing wire spool. Similarly a used wire spool 314 for use with DCW 310 is used in place of the existing used wire spool 214.

[0049] The existing spool traverser 218 is removed from the existing wire saw. A replacement new wire spool traverser 330 is installed. For example, traverser 330 is secured to a traverser drive mechanism associated with the removed traverser. In alternative embodiments, replacement traverser 330 includes a new drive mechanism. In such a case, the new drive mechanism may be coupled to control system 376 such that control system 376 controls the position (e.g., along the Z-axis) of new wire spool traverser 330. Control system 376 is programmed or reprogrammed to control traverser 330 as described herein. Control system 376 is a new system that replaces control system 276 of the existing standard wire saw. In

alternative embodiments, existing control system 276 of the standard wire saw is reprogrammed to control replacement traverser 330 as described herein.

[0050] Replacement traverser 330 includes two guide rollers 340 that position wire 310 (e.g., DCW) relative to a pulley 440 included in traverser 330. The two guide rollers 340 position wire 310 away from one or more shoulders of the pulley 440 (e.g., the two guide rollers 340 may position wire 310 substantially equidistant from two opposite shoulders of the pulley 440) . In some embodiments, the two guide rollers 340 are made of soft polyurethane .

[0051] The two guide rollers 340 are positioned vertically (e.g., rotate about an axis

perpendicular to the Z-axis) . The pulley 440 of

replacement traverser 330 is positioned horizontally (e.g., rotates about an axis parallel to the Z-axis) . The pulley 440 of replacement traverser 330 may be oriented 90 degrees relative to an existing pulley of an existing traverser (e.g., traverser 218) that is removed during the

modification. This allows replacement traverser 330 to have a greater range of motion in the Z-axis than traverser 218, as the pulley 440 is parallel to a housing of the wire saw rather perpendicular. This allows replacement

traverser 330 to wind new wire spool (e.g., during a backward winding cycle) along the entirety of new wire spool 312 preventing an accumulation of wire 310 in one section of new wire spool 312 that may lead to breaking of DCW.

[0052] The pulley 440 of replacement traverser 330 is positioned in a plane (e.g., X-Y plane) parallel to the plane in which other pulleys (e.g., 220, 222, 224, 226, and/or other pulleys) of the wire saw are positioned. In some embodiments, replacement traverser 330 includes a pulley 440 that has the same orientation (e.g., rotation about an axis parallel or perpendicular to the Z-axis) as one or more existing pulleys of the wire saw which are not removed during modification of the wire saw for use with DCW. For example, pulleys 220, 222, 224, 226, and/or 228 of the existing wire saw may be retained with traverser 330 including a pulley 440 which has the same orientation as one or more of the pulleys 220, 222, 224, 226, and/or 228 to reduce load and/or stress on the DCW.

[0053] Replacement traverser 330 is positioned relative to new wire spool 312 such that an existing roller (e.g., roller 216 is bypassed). Bypassing an existing roller of the existing wire saw may reduce the number of contact points of wire 310 and/or reduce the number of direction changes of wire 310. This may in turn reduce the stress and/or load on wire 310 resulting in a decreased likelihood for breakage. The existing roller (e.g., roller 216) is removed from the existing wire saw in some cases, and in others, is retained but not used.

[0054] Replacement new wire spool traverser 330 includes two guide rollers 340 that are connected to at least one load cell (not shown in FIG. 3) . The load cell measures strain. For example, the load cell may be or include a strain gauge. Wire 310 passes between the two guide rollers 340 while unspooling from new wire spool 312 during a forward winding leg and passes between the two guide rollers 340 while spooling onto new wire spool 312 during a backward winding leg. Strain caused by wire 310 contacting one of the two rollers 340 is measured by the load cell. In alternative embodiments, the two rollers 340 are connected to two or more load cells. For example, each roller of the two rollers 340 may be connected to

individual load cells. In other embodiments, the two rollers 340 are not connected to one or more load cells. For example, each roller of the two rollers 340 may be connected to a switch that is activated by displacement of the associated roller. Alternatively, the two rollers 340 do not provide feedback control for replacement new wire spool traverser 330, but rather guide wire 310 into replacement new wire spool traverser 330.

[0055] During a forward winding cycle, the position of traverser 330 is controlled by control system 376 based on feedback from the load cell. Traverser 330 is moved (e.g., driven by a motor) along the Z-axis to keep wire 310 perpendicular to new wire spool 312 (e.g., the axis of rotation of new wire spool 312 parallel to the Z- axis) as wire 310 is unwound from new wire spool 312.

Control system 376 is programmed to control movement of the replacement new wire spool traverser 330, such that control system 376 receives inputs from the at least one load cell and controls, in response to strain detected by the load cell, a motor driving traverser 330 to position the traverser 330 such that the detected strain is reduced or eliminated. When wire 310 engages against one of the two rollers 340, traverser 330 is not perpendicular to wire 310. For example, traverser 330 may be moving too quickly or slowly compared with a winding pitch of wire 310 on new wire spool 312. The force of wire 310 contacting one of the two rollers 340 causes a strain to be detected by the load cell. In response to detected strain, the speed and/or direction of movement of traverser 330 along the Z- axis may be changed to reduce the measured strain. This allows traverser 330 to adapt to the winding pitch of wire 310 on new wire spool 312.

[0056] The two guide rollers 340 are positioned on either side of a wire path (e.g., on either side of wire 310) such that when wire 310 contacts either roller a resulting strain is detected by the load cell. Wire 310 pulling upward on one of the two rollers 330 causes tension in the load cell connecting the two rollers 330 to replacement new wire spool traverser 330 that is measured as positive strain. Wire 310 pulling downward on the other of the two rollers 330 causes compression in the load cell connecting the two rollers 330 to replacement new wire spool traverser 330. A positive detected strain may correspond to wire 310 exerting force on one roller (e.g., pulling upward) and a negative detected strain corresponds to wire 310 exerting force on the other roller of the pair of rollers 340 (e.g., pulling downward). Control system 376 controls a motor to drive replacement traverser 330 in a first direction in response to detected positive strain and to drive the traverser in a second, opposite direction, in response to detected negative strain. Alternatively, control system 376 may control a motor to drive replacement traverser 330 at an increased or decreased speed depending on at least one of the detection of positive or negative strain. The speed change may also be based on an overall direction of movement (e.g., positive or negatively along the Z-axis) . Detected strain, positive or negative, may result in opposite adjustments to the speed of replacement traverser 330 depending on the current overall direction of movement of traverser 330.

[0057] When wire 310 reaches one of the two flanges (not shown) of new wire spool 312, control system 376 changes the direction of movement of replacement traverser 330 along the Z-axis. The flanges of new wire spool 312 are at the ends of the new wire spool 312 and define the vertical limits within which wire 310 is contained by new wire spool 312. In some embodiments, replacement traverser 330 includes two switch sensors located on each end of a shaft on which replacement traverser 330 travels along the Z-axis. When one of the two switches is activated (e.g., by a portion of

replacement traverser 330 coming into contact with the switch) , control system 376 reverses the direction of a motor driving replacement traverser 330. In some

embodiments, an encoder additionally or alternatively measures the location of replacement traverser 330 along the Z-axis for control of the direction of movement of traverser 330. In some embodiments, an encoder (not shown) determines the amount of wire 310 that has been unwound from spool 312 and controls the direction of traverser 330 along the Z-axis based on the amount of wire that has been unwound .

[0058] In some embodiments, control system 376 does not control replacement traverser 330 based on input from the load cell during backward winding cycles. Control system 376 drives replacement traverser 330 at a

substantially constant speed and changes the direction of drive based on input from the switches described herein. Alternatively, an encoder may be used to control direction changes. In an alternative embodiment, control system 376 controls replacement traverser 330 based on input from the load cell during backward winding cycles as described herein with respect to the forward winding cycle.

[0059] An existing pulley 228 or take up traverser of the existing standard wire saw is replaced with a replacement take up traverser (not shown) similar to or the same as replacement traverser 330. The replacement take up traverser may wind and/or unwind used wire spool 314. The replacement take up traverser may have two guide rollers connected to at least one load cell configured to measure strain on the two guide rollers caused by wire 310 passing between the two guide rollers. Control system 376 is programmed to control movement of replacement new wire spool traverser 330 and the replacement take up traverser, such that, for both replacement new wire spool traverser 330 and the replacement take up traverser, control system 376 receives inputs from the at least one load cell and controls, in response to strain detected by the load cell, motors driving both traversers to position each traverser such that the detected strain is reduced or eliminated. In alternative embodiments, existing pulley 228 and/or the existing take up traverser are retained.

[0060] Pulley 220 is an existing pulley that is relocated closer to replacement traverser 330 and/or new wire spool 312. This causes wire 310 to have a longer contact arc with the pulley 440 of replacement traverser 330 in comparison to wire 110 and existing traverser

218/roller 216 (shown in FIG. 2) . The longer contact arc reduces stress on wire 310 (e.g., DCW) which reduces the likelihood of breakage. Repositioning pulley 220 allows wire 310 to be bent along the whole stroke of replacement traverser 330 and prevents interference between wire 310 and the body of the wire saw. In alternative embodiments, pulley 220 is not repositioned but is retained in its original position.

[0061] Still referring to FIG. 3, a wire positioning system 342 is installed on the existing standard wire saw during modification for use with DCW. The wire positioning system 342 positions wire 310 away from at least one shoulder of at least one existing pulley. For example, the wire positioning system 342 positions wire 310 away from a shoulder of pulley 220 (e.g., functioning as a directional pulley) . The wire positioning system 342 includes at least first pair of rollers 332. Each pair of rollers included in the wire positioning system 342 are positioned with their axes of rotation perpendicular to the axis of rotation of an adjacent pulley for with the pair of rollers aligns wire 310. For example, first pair of rollers 332 have axes of rotation perpendicular to the Z- axis, with a pulley of replacement traverser 330 having an axis of rotation parallel to the Z-axis. The pair of rollers are positioned to substantially center wire 310 between the shoulders of the adjacent pulley for which the pair of rollers aligns wire 310. For example, first pair of rollers 332 is positioned along the Z-axis such that the range in which wire 310 is supported by first pair of rollers 332 (e.g., defined by the spacing between each roller in the Z-axis) is substantially aligned with the center, along the Z-axis, of a pulley included in

replacement traverser 330. The rollers may be made of soft polyurethane to reduce wear caused by wire 310 slipping on the rollers and/or accelerating the rollers.

[0062] First pair of rollers 332 are positioned after replacement new wire spool traverser 330, relative to new wire spool 312 during forward winding. The wire management system 342 may further include second pair of rollers 334 positioned after first pair of rollers 332. The first pair of rollers 332 and second pair of rollers 334 are aligned in two planes (e.g., the Z-X plane and the X-Y plane) . First pair of rollers 332 and second pair of rollers 334 are positioned (e.g., along the Z-axis) to align wire 310 with existing directional pulley 220 which feeds additional existing pulley 222 or existing cutting web system 102, such that wire 310 is positioned away from a shoulder of existing directional pulley 220 regardless of the position of replacement new wire spool traverser 330 along the Z-axis.

[0063] First pair of rollers 332 are connected to the body of the existing wire saw. In other

embodiments, first pair of rollers 332 is connected to replacement traverser 330 with a bracket or other

connector, such that the path between first pair of rollers 332 is substantially aligned along the Z-axis with a point equidistant, along the z-axis, between the shoulders of the pulley of replacement traverser 330.

[0064] The wire positioning system 342 further may further include a third pair of rollers 336 positioned after existing cutting web 102 and after a second existing directional pulley 226. The wire positioning system 342 may also include a fourth pair of rollers 338 positioned after third pair of rollers 336 and prior to a take up traverser (not shown) which feeds used wire spool 314 and/or existing pulley 228 (e.g., a directional pulley) . The third pair of rollers 336 and the fourth pair of rollers 338 are aligned in two planes (e.g., Z-X plane and X-Y plane) and the third pair of rollers 336 and the fourth pair of rollers 338 are positioned to align wire 310 with existing directional pulley 226, such that wire 310 is positioned away from a shoulder of existing directional pulley 226 regardless of the position of the take up traverser .

[0065] In addition to aligning wire 310 with one or more components regardless of the position of replacement traverser 330 and/or a take up traverser, each individual pair of rollers (e.g., second pair of rollers 334) individually aligns wire 310 with the component adjacent to the pair of rollers. Furthermore, while described as rollers, each pair of rollers may be, in various embodiments, a pair of rollers, pair of pulleys, or pair of other components that support, align, and/or guide wire 310. In some embodiments, the wire management system 342 includes more or fewer pairs of rollers. The pairs of rollers may be installed in locations as described and/or elsewhere in the existing wire saw.

[0066] The wire management system 342 reduces the likelihood of breakage of wire 310 (e.g., DCW) by reducing or eliminating contact between wire 310 and one or more pulley shoulders. As DCW has a rougher surface in comparison to standard wire used with loose abrasive, DCW is more likely to hang up on a pulley shoulder than standard wire. Hang ups can impart force and/or stress onto wire 310 which can cause breakage. Therefore, reducing or eliminating contact between wire 310 and pulley shoulders reduces the likelihood of breakage. Furthermore, hang ups can cause wire 310 to jump a pulley shoulder and fall out or off the pulley. Reducing hang ups by aligning wire 310 away from pulley shoulders using the wire

positioning system 342 reduces the likelihood of this occurring .

[0067] The third pair of rollers 336 and/or the fourth pair of rollers 338 may unbalance other existing components of wire management system 300. For example, the third pair of rollers 336 and/or the fourth pair of rollers 338 may prevent wire 310 from disengaging with pulley 226 and or pulley 228, but may unbalance one or more of pulley 226 and pulley 228. In some embodiments, pulley 228 is included in an existing take up traverser of the existing standard wire saw. Unbalancing of pulley 228 negatively impacts the performance of the existing take up traverser. A back support may be added to the existing take up traverser to reduce or eliminate potential unbalancing resulting from the third pair of rollers 336 and/or the fourth pair of rollers 338. For example, the back support may be a linear guide. The linear guide may also reduce vibration in the take up traverser caused by a worm gear or other drive mechanism that positions the traverser.

Additionally or alternatively, a counterweight is added to the existing take up traverser in addition to or in place of the back support to prevent or reduce potential

unbalancing caused by one or more of the pairs of rollers 336, 338. [0068] FIG. 4A is a top view of an example replacement traverser 330. Replacement traverser (s) 330 are used to replace an existing wire spool traverser (e.g., traverser 218) and/or an existing used wire spool take up traverser (e.g., a take up traverser including pulley 228) as described above.

[0069] Guide rollers 340 of replacement traverser 330 include a first guide roller 444 and a second guide roller 446. The first guide roller 444 is positioned below a wire which is wound/unwound by replacement

traverser 330. The second guide roller 446 is positioned above the wire. Guide rollers 444, 446 position wire 310 centered, vertically on a pulley 440 of traverser 330.

Guide rollers 444, 446 are connected to traverser body 442 by arms 448, 450 and load cell 452. Traverser 330 moves vertically while winding/unwinding the wire from a spool (e.g., new wire spool 312 or used wire spool 314) as described below.

[0070] A front view of replacement traverser 330 is shown in FIG. 4B. Guide rollers 444, 446 define a wire path that is substantially centered with a vertical midpoint 466 between the shoulders of pulley 440. Guide rollers 444, 446 extend horizontally to maintain the wire's position between guide rollers 444, 446. Guide rollers 444, 446 are connected to the load cell 452 and/or a bracket supporting load cell 452 with arms 448, 450. As described herein, the wire exerts a force on at least one of guide rollers 444, 446 when the wire is not

perpendicular to the spool associated with replacement traverser 330 (e.g., new wire spool 312) . This force causes deformation (e.g., elastic deformation) in arms 448, 450 and/or load cell 452 that is measured by load cell 452.

[0071] For example, load cell 452 may be or include a strain gauge that spans arms 448, 450 such that deformation is measured as a change in voltage.

Replacement traverser 330 is controlled based on the output from load cell 452 in some embodiments as described herein. For example, replacement traverser 330 is raised or lowered, relative to saw body 460 to which replacement traverser 330 is connected, to reduce strain measured by load cell 452. If the wire is at a descending angle from the spool to replacement traverser 330, the wire is guided into pulley 440 by upper guide roller 444 that pulls the wire down. This causes arm 448 to flex upwards (e.g., deform) which is registered by load cell 452 (e.g., as tension and/or positive strain) . In response to the positive strain the speed of replacement traverser 330 in the vertical direction may be altered (e.g., through control of a motor driving replacement traverser 330) . For example, if replacement traverser 330 is moving in a downward direction (e.g., pulley 440 is moving toward saw body 460) and positive strain is measured, the speed may be decreased until the measured strain is below a

predetermined threshold value (e.g., absolute value of strain) or within a predetermined range. If replacement traverser 330 is moving in an upward direction (e.g., away from saw body 460) and positive stain is measured, the speed may be increased.

[0072] Load cell 542 and/or a bracket supporting load cell 542 is connected to traverser body 442. Traverser body 442 supports pulley 440, load cell 452, and guide rollers 444, 446. Traverser body 442 is connected to a drive arm 454 that is driven by a motor 458 to position traverser body 442. In some embodiments, drive arm 454 is a worm driven by a corresponding gear which is in turn driven by motor 458. In an alternative embodiment, drive arm 454 is a rack and motor 458 drives a pinion meshed with drive arm 454. In a further alternative embodiment, traverser body 442 is attached to a nut in contact with drive arm 454 which is a ball screw driven by motor 458. In other alternative embodiments, traverser body 442 is driven by other sources of linear movement. For example, traverser body 442 may be driven by a

hydraulic ram. Motor 458 is attached to the saw body 460 of the wire saw 100 to remain in a fixed position relative to traverser body 442 of replacement traverser 330.

Alternatively, motor 458 is fixed to body 442 and moves, along with body 442, relative to drive arm 454 which is fixed to saw body 460 of the wire saw 100.

[0073] Drive arm 454 extends within saw body 460. A portion of drive arm 454 extending within saw body 460 may, at least partially, secure replacement traverser 330 to saw body 460. The portion may also extend within saw body 460 to provide replacement traverser 330 with a greater stroke (e.g., greater range of motion) . In alternative embodiments, replacement traverser 330 has a different configuration. For example, drive arm 454 may not extend within saw body 460.

[0074] Replacement traverser 330 includes limit switches 456. Limit switches 456 are triggered when replacement traverser is at one of two stroke limits.

Activation of limit switch 456 causes motor 458 to reverse drive directions. Limit switches 456 are located on the underside of body 442 such that limit switch 456 contacts motor 458 at the end of the stroke. Limit switches 456 are further located on a flange or otherwise connected to drive arm 454 to contact motor 458 at the end of the stroke.

Limit switches may be any type of switch (e.g., a button switch, reed switch, pressure transducer, or other type of switch) . In other embodiments, limit switches 456 are positioned elsewhere along replacement traverser 330. In still further embodiments, replacement traverser 330 does not include limit switches 456. For example, replacement traverser 330 may use an encoder to measure its location and cause motor 458 to reverse drive directions based on the location of replacement traverser 330.

[0075] Referring now to FIG. 4C, a side view of replacement traverser 330 is illustrated. Guide rollers 444, 446 are aligned vertically (e.g., positioned on top of one another) . In alternative embodiments, guide rollers 444, 446 are offset vertically (e.g., are centered on two different, offset vertical axes) . The vertical spacing between guide rollers 444, 446 is defined to center the wire vertically on pulley 440. The vertical spacing between guide rollers 444, 446 is substantially the diameter of the wire. In alternative embodiments, other spacing may be used (e.g., twice the diameter of the wire, three times the diameter of the wire, etc.) .

[0076] In some embodiments, replacement traverser 330 includes a linear guide 462 to support traverser body 442 and/or reduce unbalancing of traverser 330 caused by wire positioning system 342. Linear guide 462 be connected to traverser body 442 and travel within a guide 464 fixed to saw body 460. Linear guide 462 may extend partially within saw body 460. Linear guide 462 supports replacement traverser 330, at least in part, and may prevent bending of drive arm 454. Linear guide 462 also prevents or reduces vibrations in replacement

traverser 330 caused by motor 458 and/or other components driving drive arm 454. In alternative embodiments, replacement traverser 330 does not include linear guide 462. In some embodiments, linear guide 462 and/or guide 464 are added to an existing traverser (e.g., a take up traverser) of a standard wire saw.

[0077] In some embodiments, replacement traverser 330 includes counter weight 478 to support traverser body 442 and/or reduce unbalancing of traverser 330 caused by wire positioning system 342. Counter weight 478 is connected to traverser body 442 at either end or a point in between. Counter weight 478 may be connected to traverser body 442 opposite linear guide 462 or other support component. In alternative embodiments, replacement traverser 330 does not include counter weight 478. In some embodiments, counter weight 478 is added to an existing traverser (e.g., a take up traverser) of a standard wire saw.

[0078] Referring now to FIG. 5A, an example of wire management system 500, using an alternative wire positioning system 576, is illustrated. Wire management system 500 and/or elements thereof may be used in

combination with or in place of wire management system 300 and/or elements thereof illustrated in FIG. 3. Parts retained during modification of an existing wire saw are indicated using reference numbers corresponding to the parts shown in FIG. 2. Parts common to the modification using either wire management system 300 or wire management system 500 are indicated using reference numbers

corresponding to the parts shown in FIG. 3.

[0079] The alternative wire positioning system 576 (e.g., support pulleys 566, 568, 570) may be used in place of a wire positioning system 342 having pairs of rollers (e.g., first pair of rollers 332), in concert with pairs of rollers, or in addition to pairs of rollers separately with the same wire saw. The alternative wire positioning system 576 described herein may perform the same function (s) (e.g., aligning wire 310 with other pulleys) and/or provide the same benefits as the wire positioning system 342 described with reference to FIG. 3. The support pulleys (e.g., 566, 568, 570) have a larger diameter than the pairs of rollers which may increase the life of the support pulleys due to increased contact surface between wire 310 and the support pulleys and a reduced rotary speed in comparison to the pairs of rollers. In alternative embodiments, the support pulleys have other diameters .

[0080] The wire positioning system 576 includes a first support pulley 570 positioned adjacent to a first existing pulley. For example, first support pulley 570 is installed adjacent to directional pulley 226. First support pulley 570 has an axis of rotation perpendicular to the axis of rotation of the first existing pulley. For example, first support pulley 570 rotates about an axis perpendicular to the Z-axis and directional pulley 226 rotates about an axis parallel to the Z-axis. First support pulley 570 is positioned vertically along the Z- axis (e.g., connected to a support structure of directional pulley 226) such that wire 310 passing over first support pulley 570 is substantially aligned with a midpoint between pulley shoulders of directional pulley 226. This may prevent or reduce contact between wire 310 and the

shoulders of directional pulley 226.

[0081] The wire positioning system 576 further includes a second support pulley 566 positioned adjacent to a second existing pulley. For example, second support pulley 566 is installed adjacent to pulley 228, which may be included in an existing or replacement take up traverser that winds/unwinds used wire spool 314. Second support pulley 566 has an axis of rotation perpendicular to the axis of rotation of the second existing pulley. For example, second support pulley 566 rotates about an axis perpendicular to the Z-axis and directional pulley 228 rotates about an axis parallel to the Z-axis. Second support pulley 566 is positioned vertically along the Z- axis (e.g., connected to a support structure of pulley 228, such as a take up traverser body) such that wire 310 passing over second support pulley 566 is substantially aligned with a midpoint between horizontal pulley shoulders of pulley 228. This prevents or reduces contact between wire 310 and the shoulders of pulley 228. In some

embodiments, second support pulley 566 is connected to a take up traverser that feeds used wire spool 314, with second support pulley 566 positioned after first support pulley 570 and aligned to feed pulley 228 of the take up traverser .

[0082] The wire support system 576 further includes a third support pulley 568. In some embodiments, third support pulley 568 is not installed adjacent to an existing component and/or a component for which wire 310 is being aligned. Rather, third support pulley 568 provides tension in wire 310 to maintain wire 310 in contact with first support pulley 570 and second support pulley 566. Third support pulley 570 rotates about an axis (e.g., the Z-axis) parallel with the axes of rotation of first support pulley 570 and second support pulley 566. Third support pulley 570 is positioned at a different point along the Z- axis (e.g., vertically) from first support pulley 570 and second support pulley 566. Third support pulley 568 is positioned closer to a support structure of the wire saw than the first support pulley 570 and second support pulley 566. For example, third support pulley 568 may be

connected to a saw body.

[0083] Referring now to FIGS. 5A and 5B, illustrating a side view of a portion of wire management system 500, wire 310 travels under third support pulley 568. This arrangement provides a downward force that maintains wire 310 in contact with first support pulley 570 and second support pulley 566. In other words, third support pulley 568 is connected to a support structure of the existing wire saw (e.g., saw body 460) such that third support pulley 568 is closer to the support structure than both first support pulley 570 and second support pulley 566 such that third support pulley 568 tensions wire 310 and wire 310 is in contact with first support pulley 570, second support pulley 566, and third support pulley 568 during operation of the wire saw. First support pulley 570 may be connected to a mounting structure of an adjacent pulley (e.g., pulley 226) by bracket 572. Third support pulley 568 may mounted to saw body 460 by bracket 574. Second support pulley 566 may be mounted to an adjacent pulley (e.g., pulley 228) by bracket 574.

[0084] In alternative embodiments, wire 310 may pass under first support pulley 570 and under second support pulley 566. In such a case, third support pulley 568 is located above first support pulley 570 and second support pulley 566 (e.g., higher along the Z-axis) , and wire 310 passes over third support pulley 568.

[0085] Referring again to FIG. 5A, in some embodiments, a first wire 310 feed path of an existing directional pulley (e.g., pulley 226) and a second existing pulley (e.g., 228 of the take up traverser) is parallel with a first plane (e.g., the X-Y plane) . A second wire feed path of first support pulley 570, second support pulley 566, and third support pulley 568 is parallel with a second plane (e.g., the Z-Y plane) perpendicular to the first plane. For example, wire 310 may travel horizontally across pulleys 226 and 228 and travel vertically across support pulleys 566, 568, and 570.

[0086] Referring now to FIG. 6, method 600 of modifying an existing standard wire saw for use with DCW is illustrated according to one embodiment. It should be understood that method 600 may include more or fewer steps than those illustrated. Furthermore, the illustrated steps may occur in any order.

[0087] Modifying an existing standard wire saw according to method 600 includes removing 676 an existing wire spool traverser. Method 600 further includes

installing 678 a replacement new wire spool traverser having at least one load cell. The replacement traverser may include two guide rollers connected to the at least one load cell that measures strain on the two guide rollers caused by a wire passing between the two guide rollers. Method 600 further includes bypassing 680 an existing roller. For example, the replacement new wire spool traverser may be positioned such that the wire bypasses an existing roller rather than travelling across the existing roller .

[0088] Method 600 includes installing 682 a wire guide system or wire positioning system having pairs of rollers and/or support pulleys positioned at different distances from the saw support structure. This may include installing a first pair of rollers positioned after the replacement new wire spool traverser, relative to the new wire spool during forward winding and installing a second pair of rollers positioned after the first pair of rollers. The first pair of rollers and the second pair of rollers are aligned in two planes and wherein the first pair of rollers and the second pair of rollers are poisoned to align the wire with an existing directional pulley that feeds an additional existing pulley or an existing cutting web system, such that the wire is positioned away from a shoulder of the existing directional pulley regardless of the position of the replacement new wire spool traverser. Installing a wire guide system or wire positioning system having pairs of rollers and/or support pulleys positioned at different distances from the saw support may

additionally or alternatively include installing a first support pulley adjacent to an existing directional pulley positioned after an existing cutting web system, relative to the new wire spool during forward winding and installing a second support pulley connected to a take up traverser that feeds a used wire spool. The second support pulley is positioned after the first support pulley and aligned to feed a pulley of the take up traverser. A third support pulley is installed connected to a support structure of the existing wire saw such that the third support pulley is closer to the support structure than both the first support pulley and the second support pulley and such that the third support pulley tensions the wire and the wire is in contact with the first support pulley, second support pulley, and third support pulley during operation of the wire saw.

[0089] Method 600 further includes programming 684 a control system for control (e.g., load cell based control) of a traverser. The control system may be an existing control system of the existing standard wire saw or may be added to the standard wire saw to control a replacement traverser (e.g., replacement a new wire spool traverser, replacement take up traverser, etc.).

Programming may include, for example, programming the control system to control movement of the replacement new wire spool traverser, such that the control system receives inputs from the at least one load cell and controls, in response to strain detected by the load cell, a motor driving the traverser to position the traverser such that the detected strain is reduced or eliminated. The control system may be programmed to receive inputs from at least one load cell of the replacement new wire spool traverser and control a position of the replacement new wire

traverser based on the received inputs. The replacement new wire traverser may include two guide rollers positioned on either side of a wire path such that when the wire contacts either roller a resulting strain is detected by the load cell. A positive detected strain may correspond to the wire exerting force on one roller and a negative detected strain corresponds to the wire exerting force on the other roller of the pair of rollers. The control system may be programmed to cause a motor to drive the traverser in a first direction in response to detected positive strain and to drive the traverser in a second, opposite direction, in response to detected negative strain and/or alter a speed of the motor.

[0090] In some embodiments a wire breakage system is added to the existing standard wire saw as part of the modification for use with DCW. Wire breakage detection systems for a standard wire saw using non- conductive or low conductive fluids (e.g., a loose abrasive slurry) , may apply a current or voltage signal to the new wire spool and receive the signal at the used wire spool. The signal is analyzed by a control system (e.g., a programmable logic controller) . When an interruption of signal is detected, the control system determines that the wire is broken and the saw is stopped. The signal passes through the cutting web because there is no dispersion due to the slurry. In some embodiments, the existing slurry nozzles of a standard wire saw may be modified to provide a cooling fluid and/or fluid to remove cutting debris (e.g., water may be applied through the existing slurry nozzles) . In the case of a water based coolant or slurry, the fluid may be a conductor that interrupts the signal and "false" wire breakages are detected by the control system.

[0091] FIG. 7 illustrates components of control system 376 according to one embodiment. Control system 376 includes a communication interface 702, processor 704, and memory area 706. Communication

interface 702 is configured to receive inputs from one or more systems of the modified wire saw such as load cell 452 of replacement traverser 330, encoder 710, one or more spool motors 708 which drive new wire spool 312 and/or used wire spool 314, and/or other systems. Processor 704 is configured to process received inputs based on a program, algorithm, or other instructions stored in memory area 706 to perform the functions of control system 376 described herein. Communication interface 702 further provides outputs, as controlled by the processor 704, which control one or more systems of the modified wire saw such as motor 458 of replacement traverser 330, one or more spool motors 708, and/or other systems.

[0092] The processor 704 may include one or more processing units (e.g., in a multi-core

configuration) . The memory area 706 is any device allowing information such as executable instructions and/or data to be stored and retrieved. The memory area 706 may include one or more computer readable storage devices or other computer readable media, including transitory and non- transitory computer readable media.

[0093] The control system 376 also includes a communication interface 702, which may be communicatively connected to one or more remote devices, such as the load cell 452 of replacement traverser 330, motor 458 of replacement traverser 330, spool motor (s) 708, encoder 710, and/or other systems of the modified wire saw. The

communications interface 702 is connected to the remote devices by a wired or wireless connection that allows for unidirectional or bidirectional communication between the remote devices and the communication interface 376. The communication interface 702 may include, for example, a wired or wireless network adapter or a wireless data transceiver for use with a mobile phone network (e.g., Global System for Mobile communications (GSM) , 3G, 4G or Bluetooth) or other mobile data network (e.g., Worldwide Interoperability for Microwave Access (WIMAX) ) .

[0094] The memory area 706 may include, but is not limited to, any computer-operated hardware suitable for storing and/or retrieving processor-executable instructions and/or data. The memory area 706 may include random access memory (RAM) such as dynamic RAM (DRAM) or static RAM (SRAM) , read-only memory (ROM) , erasable programmable readonly memory (EPROM) , electrically erasable programmable read-only memory (EEPROM) , and non-volatile RAM (NVRAM) . Further, the memory area 706 may include multiple storage units such as hard disks or solid state disks in a

redundant array of inexpensive disks (RAID) configuration. The memory area 706 may include a storage area network (SAN) and/or a network attached storage (NAS) system. In some embodiments, the memory area 706 includes memory that is integrated in the control system 376. For example, the control system 376 may include one or more hard disk drives as the memory area 706. The memory area 706 may also include memory that is external to the control system 376 and may be accessed by a plurality of control systems. The above memory types are exemplary only, and are thus not limiting as to the types of memory usable for storage of processor-executable instructions and/or data.

[0095] In some embodiments, control system 376 is a logic circuit, an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) , a microcontroller, a programmable logic controller (PLC) , or other hardware and software for controlling components of the modified wire saw as described herein.

[0096] FIG. 8 illustrates the modified wire saw shown in FIG. 3 with additional modifications. In some embodiments, the modified wire saw includes one or more of a replacement wire breakage detection system 800, modified slurry nozzles 806 for use with a coolant fluid, a cutting fluid filtration system 808, and a bearing box temperature control system 810. In some embodiments, one or more of these additional modifications are included in the modified wire saw as shown in FIGS. 5A and 5B.

[0097] In some embodiments, the existing wire breakage detection system is replaced during the

modification for use with DCW. The replacement wire breakage detection system 800 may be a conducting bar 802 (e.g., a steel bar) held on the saw through isolated brackets 804 (e.g., made of a non-conducting material) and positioned close to the wire 310 (e.g., in a portion of the wire management system 300) . The bar 802 is connected to the control system 376 through a cable (not shown) and a voltage signal is sent through it. The bar 802 is isolated from the saw and the cutting web 102, so the signal is sent and received back by the control system 376. If the wire 310 breaks, it touches the bar 802 generating a disruption of the signal that is detected by the control system 376. In response, the control system 376 stops the saw. In alternative embodiments, the replacement wire breakage detection system may be or include other systems. For example, cameras (not shown) may be used to monitor wire integrity. Such a system may be more accurate than a conductive bar based system, but the environment within the saw may be dirty requiring frequent maintenance and cleaning of the cameras .

[0098] In some embodiments, the existing standard wire saw uses high flow slurry nozzles (e.g., 2, 3, 4, etc. nozzles) . The nozzles maybe modified to apply a glycol based coolant or water based coolant for use with DCW. In some cases, the slurry is simply replaced with the coolant. In the case of a water based coolant, the flowrate from unmodified slurry nozzles may be too high (e.g., 10 times the desired flow rate) . In some

embodiments, modifying the existing standard wire saw includes replacing the slurry nozzles with spray nozzles 806 having a different profile. The spray nozzles 806 generate a mist of coolant and apply it to the cutting web 102. The reduced flow rate provides enough coolant to keep the wire 310 wet, to remove the cutting debris from the cutting section, and to cool the wire 310 and the

semiconductor ingot, but it is not large enough to generate significant turbulence, which can deflect the wire 310 during cutting and degrade cut quality (e.g., result in rougher wafers cut from the semiconductor ingot.

[0099] In some embodiments, modifying an existing standard wire saw for use with DCW includes installing a cutting fluid filtration system 808. Cutting silicon results in swarf and/or cutting debris. The coolant fluid becomes contaminated with silicon and acts as both a lubricant and barrier to heat transfer due to the silicon. The lubricating nature of the contaminated coolant fluid degrades the wire's cutting ability, which relies on abrasive force to cut the silicon ingot. The cutting fluid filtration system 808 may be placed in line (e.g., just before the nozzles 806 applying the coolant fluid) to remove silicon from the cutting/coolant fluid. The filtration system may use any type of filtration (e.g., centrifuge, bag, cartridge, etc.). The filtration system 808 is coupled to the nozzles 806 by piping (not shown) and includes a collector (not shown) which collects coolant fluid beneath the cutting web 102.

[0100] In some embodiments, modification of an existing standard wire saw for use with DCW includes modifying a cutting web bearing box temperature control system 810. Using DCW to slice wafers may result in higher warp values compared with loose abrasive cutting as cutting with DCW takes significantly less time. To compensate for DCW and to reduce warp degradation in the sliced wafers, the bearing box temperature control system is modified. In some existing standard wire saws a single cooling loop is used to cool multiple bearings of the cutting web

simultaneously. This prevents control of the temperature of individual bearings. In some embodiments, modifying the existing standard wire saw includes installing a dedicated cooling loop for each bearing. This allows for temperature control of each individual bearing through their respective cooling loops (e.g., by the control system altering the amount of coolant provided to each bearing via the

individual cooling loops) . By controlling the individual temperatures, warp degradation may be reduced. In some embodiments, the control system measures the temperature of the bearings themselves, rather than that of the coolant (e.g., water) within each loop, for feedback control. This may result in greater temperature control accuracy. [0101] Systems and methods of modifying a standard wire saw for use with DCW have been described herein. In some alternative embodiments, one or more of the systems and/or methods for modifying a standard wire saw may be used in conjunction with standard wire and loose abrasive. The same modifications may be made to an existing standard wire saw to increase the life of standard wire by reducing stress and/or force on the standard wire. Loose abrasive may continue to be used with standard wire following one or more of the modifications described herein .

[0102] When introducing elements of the present invention or the embodiment (s ) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. The use of terms indicating a particular orientation (e.g., "top", "bottom", "side", "down", "up", etc.) is for convenience of description and does not require any particular orientation of the item described .

[0103] As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawing [s] shall be interpreted as

illustrative and not in a limiting sense.