[0001] This application claims the benefit of priority of U.S. Provisional Application Serial No. 61/817039 filed on April 29, 2013, the content of which is relied upon and incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] The present invention relates to apparatuses and methods for processing thin substrates on carrier substrates, and more specifically, to thin substrates of flexible glass on carrier substrates.

BACKGROUND

[0003] Today, flexible plastic films are commonly used in flexible electronic devices associated with Photovoltaic (PV), Organic Light Emitting Diodes (OLEDs), Liquid Crystal Displays (LCDs), touch sensors, flexible electronics and patterned Thin Film Transistor (TFT) applications.

[0004] Flexible glass substrates offer several technical advantages over flexible plastic technology. One technical advantage is the ability of the glass to serve as a moisture or gas barrier, a primary degradation mechanism in OLED displays, OLED lighting and organic photovoltaic devices. A second advantage is in its potential to reduce overall package size (thickness) and weight through the reduction or elimination of one or more package substrate layers. Other advantages of flexible glass substrates include benefits in optical transmission, dimensional stability, thermal capability and surface quality.

[0005] As the demand for thinner/flexible glass substrates (less than 0.3 mm thick) is driven into the electronic display industry, panel manufacturers face a number of challenges to handling and adapting to the thinner/flexible glass substrates. One option is to process thicker sheets of glass then etch or polish the panel to thinner overall net thickness. This enables the use of existing panel fabrication infrastructure based on substrates 0.3 mm thick or thicker, but adds finishing costs to the end of the process along with a potential reduction in yield. A second approach is to re-engineer the existing panel process for thinner substrates. Glass loss in the process is a major interruption, and significant capital would be required for minimizing handling loss in sheet-to-sheet processes based on non-supported flexible glass substrates. A third approach is to utilize Roll-to-Roll processing technologies or technologies based on roller handling for the thin flexible glass substrates.

[0006] What is desired is a carrier approach that utilizes the existing capital infrastructure of the manufacturers based on rigid substrates 0.3 mm or thicker and enables processing of thin, flexible glass substrates, i.e., glass having a thickness no greater than about 0.3 mm thick. In a carrier approach, the flexible glass or portions thereof need to be extracted from the carrier. However, at the point of extraction, electronic devices or other structures have already been built on the flexible glass. Accordingly, there is a need for methods of extracting the desired parts without damaging the structures already built on the flexible glass.

SUMMARY

[0007] The present concept for extraction involves heating only a portion of a flexible glass substrate (e.g., a perimeter) through a carrier substrate with a heating device. The heating device creates a sufficient temperature gradient between a device portion of the flexible glass substrate and the perimeter portion of the flexible glass substrate without overheating the device portion to separate the device portion from the perimeter portion of the flexible glass substrate.

[0008] One commercial advantage to the present approach is that manufacturers will be able to utilize their existing capital investment in processing equipment while gaining the advantages of the thin glass sheets for PV, OLED, LCDs, touch sensors, flexible electronics and patterned Thin Film Transistor (TFT) electronics, for example.

[0009] According to a first aspect, a method of processing a flexible glass substrate comprises:

providing a substrate stack comprising the flexible glass substrate bonded to a carrier substrate; and

heating a perimeter portion of the flexible glass substrate to a temperature greater than that of a device portion of the flexible glass substrate using a heating fixture that transmits heat to the perimeter portion thereby creating a thermal gradient between the perimeter portion and the device portion and introducing tensile forces within the perimeter portion, the tensile forces separating the device portion of the flexible glass substrate from the perimeter portion along a score line minimizing damage of edges of the device portion due to thermal expansion of the perimeter portion. [0010] According to a second aspect, there is provided the method of aspect 1 , further comprising heating the heating fixture using a heat source, the heating fixture transmitting heat to the carrier substrate.

[0011] According to a third aspect, there is provided the method of aspect 2, wherein the step of transmitting the heat is by convection.

[0012] According to a fourth aspect, there is provided the method of any one of aspects 1 - 3, further comprising inhibiting heating of the device portion during heating of the perimeter portion using a thermal insulating shield.

[0013] According to a fifth aspect, there is provided the method of any one of aspects 1-4, further comprising scoring the flexible glass substrate along a boundary between the perimeter portion and the device portion.

[0014] According to a sixth aspect, there is provided the method of any one of aspects 1-5, further comprising bonding the flexible glass substrate to the carrier substrate.

[0015] According to a seventh aspect, there is provided the method of aspect 6, comprising bonding the flexible glass substrate to the carrier substrate within the perimeter portion, a bond strength between the flexible glass substrate and the carrier substrate in the perimeter portion being greater than a bond strength between the flexible glass substrate and the carrier substrate in the device portion.

[0016] According to an eighth aspect, there is provided the method of any one of aspects 1- 7, wherein the step of heating the perimeter portion of the flexible glass substrate to the temperature greater than that of the device portion includes heating the perimeter portion to a temperature of greater than about 100 °C, the device portion having a temperature of less than 100 °C.

[0017] According to a ninth aspect, a method of processing a flexible glass substrate comprises:

providing a substrate stack comprising the flexible glass substrate bonded to a carrier substrate;

scoring the flexible glass substrate along a score line, the score line defining a perimeter portion and a device portion of the flexible glass substrate;

heating the perimeter portion of the flexible glass substrate to a temperature greater than about 100 C, the device portion having a temperature of less than 100 C thereby creating a thermal gradient between the perimeter portion and the device portion; and separating the device portion of the flexible glass substrate from the perimeter portion along the score line.

[0018] According to a tenth aspect, there is provided the method of aspect 9, wherein the step of heating the perimeter portion of the flexible glass substrate comprises heating a heating fixture using a heat source, the heating fixture transmitting heat to the carrier substrate.

[0019] According to an eleventh aspect, there is provided the method of aspect 9 or aspect

10, wherein the step of heating the perimeter portion of the flexible glass substrate is by convection.

[0020] According to a twelfth aspect, there is provided the method of any one of aspects 9-

1 1, further comprising inhibiting heating of the device portion during heating the perimeter portion using a thermal insulating shield.

[0021] According to a thirteenth aspect, there is provided the method of any one of aspects 9-12, further comprising bonding the flexible glass substrate to the carrier substrate.

[0022] According to a fourteenth aspect, there is provided the method of aspect 13, comprising bonding the flexible glass substrate to the carrier substrate within the perimeter portion, a bond strength between the flexible glass substrate and the carrier substrate in the perimeter portion being greater than a bond strength between the flexible glass substrate and the carrier substrate in the device portion.

[0023] According to a fifteenth aspect a method of processing a flexible glass substrate comprises:

locating a heating fixture on a heating plate, the heating fixture including at least one wall member having at least one lower support surface in contact with the heating plate and at least one upper support surface;

locating a substrate stack comprising the flexible glass substrate bonded to a carrier substrate on the upper support surface of the heating fixture; and

heating a perimeter portion of the flexible glass substrate to a temperature greater than that of a device portion of the flexible glass substrate by heating the heating fixture using the heating plate thereby creating a thermal gradient between the perimeter portion and the device portion and introducing tensile forces within the perimeter portion.

[0024] According to a sixteenth aspect, there is provided the method of aspect 15, wherein the step of heating the perimeter portion of the flexible glass substrate is by convection. [0025] According to a seventeenth aspect, there is provided the method of aspect 15 or aspect 16, further comprising inhibiting heating of the device portion during heating the perimeter portion using a thermal insulating shield.

[0026] According to an eighteenth aspect, there is provided the method of any one of the aspects 15-17, further comprising scoring the flexible glass substrate along a boundary between the perimeter portion and the device portion.

[0027] According to a nineteenth aspect, there is provided the method of any one of aspects 15-18, further comprising bonding the flexible glass substrate to the carrier substrate.

[0028] According to a twentieth aspect, there is provided the method of aspect 19, comprising bonding the flexible glass substrate to the carrier substrate within the perimeter portion, a bond strength between the flexible glass substrate and the carrier substrate in the perimeter portion being greater than a bond strength between the flexible glass substrate and the carrier substrate in the device portion.

[0029] According to a twenty- first aspect, there is provided the method of any one of aspects 15-20, wherein the step of heating the perimeter portion of the flexible glass substrate to the temperature greater than that of the device portion includes heating the perimeter portion to a temperature of greater than about 100 °C, the device portion having a temperature of less than 100 °C.

[0030] Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the invention as exemplified in the written description and the appended drawings and as defined in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework to understanding the nature and character of the invention as it is claimed.

[0031] The accompanying drawings are included to provide a further understanding of principles of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description serve to explain, by way of example, principles and operation of the invention. It is to be understood that various features of the invention disclosed in this specification and in the drawings can be used in any and all combinations.

BRIEF DESCRIPTION OF THE DRAWINGS [0032] FIG. 1 is a side view of an embodiment of a substrate stack including a flexible glass substrate that is carried by a carrier substrate;

[0033] FIG. 2 is an exploded, perspective view of the substrate stack of FIG. 1 ;

[0034] FIG. 3 illustrates an embodiment of a method of processing the flexible glass substrate and substrate stack of FIG. 1 ;

[0035] FIG. 4 illustrate an exemplary embodiment of a heating apparatus;

[0036] FIG. 5 illustrates a perspective view of the heating apparatus of FIG. 4 in isolation;;

[0037] FIG. 6 is a schematic illustration of operation of the heating apparatus of FIG. 4; and

[0038] FIG. 7 illustrates an exemplary glass temperature distribution using the heating apparatus of FIG. 4.

DETAILED DESCRIPTION

[0039] Embodiments described herein generally relate to processing of flexible glass substrates, sometimes referred to herein as device substrates. The flexible glass substrates may be part of a substrate stack that generally includes a carrier substrate and the flexible glass substrate bonded thereto. As will be described in greater detail below, a portion of the flexible glass substrate (e.g., a perimeter) is heated through the carrier substrate with a heating device. The heating device creates a sufficient temperature gradient between a device portion of the flexible glass substrate and the perimeter portion of the flexible glass substrate without overheating the device portion. The device portion of the flexible glass substrate is protected from a certain amount of heating and kept at a relatively low temperature to avoid damage to the device portion, while the perimeter portion of the flexible glass substrate is heated to induce expansion and tensioning around the device portion for extraction from the carrier substrate. For sake of convenience and ease in description only, throughout the specification and drawings only one device portion and one perimeter are shown on any one particular flexible glass sheet. However, there may be any suitable number of device portions, including an array thereof, disposed on the flexible glass sheet, wherein one or more of the device portions are surrounded by a perimeter portion. Stated another way, the perimeter portion need not be coextensive with the periphery at the outer bounds of the flexible glass sheet, although in some instances, it may be.

[0040] Referring to FIGS. 1 and 2, a substrate stack 10 includes a carrier substrate 12 and a flexible glass substrate 20. The carrier substrate 12 has a glass support surface 14, an opposite support surface 16 and a periphery 18. The flexible glass substrate 20 has a first broad surface 22, an opposite, second broad surface 24 and a periphery 26. The flexible glass substrate 20 may be "ultra-thin" having a thickness 28 of about 0.3 mm or less including but not limited to thicknesses of, for example, about 0.01-0.05 mm, about 0.05-0.1 mm, about 0.1-0.15 mm and about 0.15-0.3 mm, or for example, 0.3, 0.29, 0.28, 0.275, 0.27, 0.26, 0.25, 0.24, 0.23, 0.225, 0.20, 0.21, 0.20, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, 0.11, 0.10, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, or 0.01 mm.

[0041] The flexible glass substrate 20 is bonded at its first broad surface 22 to the glass support surface 14 of the carrier substrate 12 using a bonding layer 30. The bonding layer may be formed of any suitable bonding materials, for example, organic or inorganic bonding materials. As shown, the bonding material of the bonding layer 30 is located about the periphery 18 and 26 of the carrier substrate 12 and the flexible glass substrate 20. The location of the bonding material can define a perimeter portion 32 of the flexible glass substrate 20 above the bonding material and a central or device portion 34 located inside of the perimeter portion 32. When the carrier substrate 12 and the flexible glass substrate 20 are bonded to one another by the bonding layer 30, the combined thickness 25 of the substrate stack 10 may be the same as single glass substrate having increased thickness as compared to the thickness of the flexible glass substrate 20 alone, which may be suitable for use with existing device processing infrastructure. For example, if the processing equipment of a device processing infrastructure is designed for a 0.7 mm sheet, and the flexible glass substrate 20 has a thickness of 0.3 mm, then thickness of the carrier substrate 12 may be selected to be something no greater than 0.4 mm, depending, for example, on thickness of the bonding layer 30. In some embodiments, however, no bonding layer 30 may be used. For example, the flexible glass substrate 20 may be bonded directly to the carrier substrate 12 using electrostatic, covalent, or van der Waals forces. The carrier substrate 12 may be surface modified (e.g., etching, scoring, etc.), spacers, or other materials, for example various coatings (e.g., adhesives or other materials having a reduced adhesion to the flexible glass substrate 20) may be applied at selected locations (e.g., beneath the device portion(s) 32) to inhibit bonding between the flexible glass substrate 20 and the carrier substrate 12 in those areas.

[0042] The carrier substrate 12 may be of any suitable material including glass, glass- ceramic or ceramic, as examples, and may or may not be transparent. If made of glass, the carrier substrate 12 may be of any suitable composition including alumino-silicate, boro- silicate, alumino-boro-silicate, soda-lime-silicate, and may be either alkali containing or alkali- free depending upon its ultimate application. The thickness of the carrier substrate 12 may be from about 0.2 to 3 mm, for example 0.2, 0.3, 0.4, 0.5, 0.6, 0.65, 0.7, 1.0, 2.0, or 3 mm, and may depend upon the thickness 28 of the flexible glass substrate 20, as noted above. Additionally, the carrier substrate 12 may be made of one layer, as shown, or multiple layers (including multiple thin sheets) that are bonded together to form a part of the substrate stack 10.

[0043] The flexible glass substrates 20 described herein may have a thickness of about 0.3 mm or less including but not limited to thicknesses of, for example, about 0.01 -0.05 mm, about 0.05-0.1 mm, about 0.1-0.15 mm, about 0.15-0.3 mm, including 0.3, 0.275, 0.25, 0.225, 0.2, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, 0.11 , 0.10, 0.09, 0.08 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, or 0.01 mm, for example. The flexible glass substrates may be formed of glass, a glass ceramic, a ceramic material or composites thereof; for the sake of convenience in reference only, the terms "flexible glass substrate" or "glass layer" may be used throughout the specification, wherein such a substrate or layer may instead be made from any of these other materials. A fusion process (e.g., down draw process) that forms high quality flexible glass substrates can be used to form the flexible glass substrates. Flexible glass substrates produced in a fusion process may have surfaces with superior flatness and smoothness when compared to glass sheets produced by other methods. Fusion processes are described in U.S. Patent Serial Nos. 3,338,696 and 3,682,609. Other suitable flexible glass substrate forming methods include a float process, updraw and slot draw methods. The flexible glass substrates 20 may be the same size and/or shape or of a different size and/or shape as the carrier substrates 12.

[0044] Referring to FIG. 3, a bonding and device portion extraction method 40 is illustrated as part of the processing of the flexible glass substrate 20. At step 42, the carrier substrate 12 and the flexible glass substrate 20 are selected based on, for example, their sizes, thicknesses, materials and/or end uses. Once the carrier substrate 12 and the flexible glass substrate 20 are selected, the bonding layer 30 may be applied to the peripheries (and/or other locations) to one or both of the glass support surface 14 and the first broad surface 22 of the flexible glass substrate 20 at step 44. Alternatively, the flexible substrate 20 may be bonded directly to the carrier substrate 12, as noted above. Any suitable methods may be used for applying the bonding layer 30, for example one or more of a pressurized application, for example, through a nozzle, spreading, melting, spin casting, spraying, dipping, vacuum or atmospheric deposition, etc.

[0045] At step 46, the flexible glass substrate 20 is adhered or otherwise bonded to the carrier substrate 12 using the bonding layer 30. To achieve a desired bond strength between the flexible glass substrate 20 and the carrier substrate 12, bonding material forming the bonding layer 30 may be heated, cooled, dried, mixed with other materials, reaction induced, pressure may be applied, for example. To achieve a reduced bond strength at the device portion of the flexible glass substrate 20, any suitable releasable materials may be used or surface altering of the carrier substrate 12. As used herein, "bond strength" refers to any one or more of dynamic shear strength, dynamic peel strength, static shear strength, static peel strength and combinations thereof. Peel strength, for example, is the force per unit width necessary to initiate failure (static) and/or maintain a specified rate of failure (dynamic) by means of a stress applied to one or both of the flexible glass substrate and carrier substrate in a peeling mode. Shear strength is the force per unit width necessary to initiate failure (static) and/or maintain a specified rate of failure (dynamic) by means of a stress applied to one or both of the flexible glass substrate and carrier substrate in a shear mode. Any suitable methods can be used to determine bond strength including any suitable peel and/or shear strength test.

[0046] Steps 48 and 50 relate to extracting devices from the flexible glass substrate 20 and/or de -bonding devices from the carrier substrate 12 so that the device portions of the flexible glass substrate 20 can be removed from the carrier substrate 12. Before and/or after releasing the device portions of the flexible glass substrate 20 from the carrier substrate 12, the flexible glass substrate 20 may be processed, for example, in the formation of a display device, for example an LCD, OLED or TFT electronics or other electronic devices for example a touch sensor or photovoltaic. For example, electrical components or color filters may be applied to the second broad surface 24 of the flexible glass substrate 20 (FIGS. 1 and 2). Additionally, final electronic components can be assembled or combined with the flexible glass substrate 20 before releasing the desired portions from the carrier substrate 12. For example, additional films or glass substrates can be laminated to the surface of the flexible glass substrate 20 or electrical components for example flex circuits or ICs can be bonded. Once the flexible glass substrate 20 is processed, an energy input 47 (thermal energy) may be selectively applied through the carrier substrate 12 thereby heating the perimeter portion 32 on the flexible glass substrate 20 at step 48. A heat shield component 49 may be used to limit heating of the device portion 34 of the flexible glass substrate 20.

[0047] At step 50, a temperature gradient is formed in the flexible glass substrate 20 between the device portion 34 and the perimeter portion 32 causing thermal expansion. A score or break line 60 may be provided in the flexible glass substrate 20 at a break location. At step 52, the device portion 34 may be extracted from the perimeter portion 32 along the break line 60.

[0048] Referring to FIG. 4, an exemplary embodiment of a heating apparatus 100 is illustrated. The heating apparatus 100 includes a heat source 102, for example provided by a heat plate 104 and a heating fixture 106 that rests on the heat plate 104. Referring also to FIG. 5 illustrating the heating fixture 106 in isolation, the heating fixture 106 includes a heating and support member 108 having an upper support surface 110 and a lower support surface 112. The upper support surface 110 supports the substrate stack 10 thereon at the support surface 16. The lower support surface 112 may be in contact with the heat plate 104. An outer peripheral surface 1 14 and an inner peripheral surface 116 extend between the upper support surface 110 and the lower support surface 1 12. Similarly to the number of device portions on the flexible glass substrate, there may be any suitable number, including a matching number of inner peripheral surfaces to heat perimeter portions that surround device portions on any given flexible glass sheet.

[0049] Referring again to FIG. 4, the heating fixture 106 includes the heating and support member 108 that includes wall members 1 18. In the illustrated embodiment of FIGS. 4 and 5, there are four wall member 118 forming a somewhat rectangular or square-shaped heating and support member 108; however, other shapes are possible, for example rounded or circular. For example, a continuous circular or oval wall member may be used to form the upper support surface of the heating and support member. Further, the wall members 118 may define any number of shapes, for example, an array of shapes. Stated another way, the configuration in FIG. 5 may be repeated across a larger area depending upon the size of the devices to be made, and the size of the flexible glass substrate. Additionally, while the wall members 1 18 are interconnected and continuous, there may be more than or less than four wall members and they may not be directly connected to form a discontinuous upper support surface. [0050] Extending between the wall members 118 is a thermal insulating shield 120. The thermal insulating shield 120 includes a support plate 122 that extends between and is integrally connected to the wall members 1 18, a first thermal insulating layer 124 that faces the flexible glass substrate 120 and a second thermal insulating layer 126 that faces the heat plate 104. The first and second thermal insulating layers 124 and 126 may extend over the entire opposite surfaces 128 and 130 of the support plate 122 and each may have conductive, convective and/or radiative insulating properties. As can be seen, the thermal insulating shield 120 may be located vertically between the upper and lower support surfaces 1 10 and 1 12. Such an arrangement can provide gaps 132 and 134 between the thermal insulating shield 120 and the heat plate 104 and the thermal insulating shield 120 and the carrier substrate 12 (or, in some cases, alternatively, the flexible glass substrate 20), which can serve to further insulate the device portion 34 of the flexible glass substrate 120 from the heat plate 104.

[0051] The heating fixture 106 may be formed by any suitable method and of any suitable materials. For example, the heating and support member 108 and the support plate 122 may be formed together from the same (e.g., aluminum) or different materials, for example through casting, stamping and/or machining. The first and thermal insulating layers 126 may be formed of any suitable insulating materials or combinations of materials, for example glass, polymers, foams, foils, etc.

[0052] Referring to FIG. 6, operation of heating apparatus 100 to extract at least a portion of the flexible glass substrate 20 from the carrier substrate 12 is illustrated schematically. The heating fixture 106 is illustrated resting on the heat plate 104 of the heat source 102. The heating fixture 106 may be supported on the heat plate 104 upon the lower support surface 1 12 that is provided by the heating support member 108 and the wall members 118. A substrate stack 150 may be located on the upper support surface 110 that is provided by the heating and support member 108 including the wall members 118. The thermal insulating shield 120 extends between each of the wall members 118 and is located between and spaced vertically from both the upper support surface 1 10 and the lower support surface 112 thereby providing the gaps 132 and 134 both above and below the thermal insulating shield.

[0053] Heating the heat plate 104 heats the heating and support member 108. The heating of the heating and support member 108 may occur primarily through contact (i.e., conduction) between the wall members 118 and the heat plate 104. However, heating of the heating and support member 108 can occur using convection and/or radiation depending on the type of heat source used, and the material from which the wall members 1 18 are made. The wall members 118, being made from a thermally conductive material, for example aluminum, conduct heat along a path represented by arrow 152 toward a carrier substrate 154 of the substrate stack 150. The heat is further conducted through the carrier substrate 154 to a flexible glass substrate 156. In this embodiment, the flexible glass substrate 156 is bonded directly to the carrier substrate 154 (e.g., using van der Waals or electrostatic bonding) at a perimeter portion 158 of the flexible glass substrate 156. A device portion 160 of the flexible glass substrate 156 may be relatively unbonded to the carrier substrate 154 such that separation of the flexible glass substrate 156 between the device portion 160 from the perimeter portion 158 of the flexible glass substrate 156 can allow the device portion 158 to be extracted from the carrier substrate 154.

[0054] As can be seen, the flexible glass substrate 156 may be processed to include one or more desired devices 162 (e.g., LCD, OLED or TFT electronics) prior to extraction of the device portion 160. A break or score line 164 may be provided (e.g., using a scribe or score wheel, or via laser scribing) about the device portion 160, defining a boundary between the perimeter portion 158 and the device portion 160 to facilitate removal of the device portion 160 from the perimeter portion 158. As the perimeter portion 158 of the flexible glass substrate 156 heats, a thermal gradient is created between the device portion 160 and the perimeter portion 158. This thermal gradient is due to increased heat transfer to the perimeter portion 158 of the flexible glass substrate 156 and reduced heat transfer to the device portion 160 due to the presence of the thermal insulating shield 120 and the gaps 132 and 134, which may be filled with a gas for example air. The thermal gradient causes thermal tensioning in the direction of arrows 170 and 172, which results in separation of the device portion 160 from the perimeter portion 158 along the score line 164.

[0055] FIG. 7 illustrates an exemplary glass temperature distribution taken using a thermovision camera (FLIR) showing a high temperature perimeter in a perimeter portion of a 0.7 mm EAGLE XG ^® glass substrate heated in a manner similar to that described above in FIG. 6. An aluminum heating fixture with thermal insulating shield was heated on a heat plate set at 350 °C. As can be seen by FIG. 7, a relatively high temperature perimeter portion of about 150 °C is shown with a relatively low temperature central portion of approximately 64 °C. [0056] The above-described temperature assisted processing of flexible glass substrates utilizes a heating apparatus that induces thermal expansion of the perimeter portion of the flexible glass substrate to extract the device portion of the flexible glass substrate, which can reduce a possibility of edge damage to the device portion during the extraction process. The heating apparatus including the heating fixture can simplify the extraction process by reducing the force required to separate the device portion of the flexible glass substrate from the carrier substrate. Additionally, or alternatively, the heating apparatus and extraction process reduce edge damage on the extracted part caused by part edges otherwise rubbing against the opposite edges of the glass after cutting and during extraction. Thus the concepts described herein may minimize part edge rubbing, preserve the edge strength and increase extraction process reliability. Manufacturers can utilize their existing capital investment in processing equipment, while gaining advantages of the use of flexible glass substrates. Increased edge strength for the device portion of the flexible glass substrate can result from the extraction processes described herein. Use of the heating fixture can reduce the possibility of damage to the flexible glass substrate due to the type and design of the heat source.

[0057] In the previous detailed description, for purposes of explanation and not limitation, example embodiments disclosing specific details are set forth to provide a thorough understanding of various principles of the present invention. However, it will be apparent to one having ordinary skill in the art, having had the benefit of the present disclosure, that the present invention may be practiced in other embodiments that depart from the specific details disclosed herein. Moreover, descriptions of well-known devices, methods and materials may be omitted so as not to obscure the description of various principles of the present invention. Finally, wherever applicable, like reference numerals refer to like elements.

[0058] Ranges can be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. [0059] Directional terms as used herein— for example up, down, right, left, front, back, top, bottom— are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0060] Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps or operational flow; plain meaning derived from grammatical organization or punctuation; the number or type of embodiments described in the

specification.

[0061] As used herein, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a "component" includes aspects having two or more such components, unless the context clearly indicates otherwise.

[0062] It should be emphasized that the above-described embodiments of the present invention, particularly any "preferred" embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of various principles of the invention. Many variations and modifications may be made to the above-described embodiments of the invention without departing substantially from the spirit and various principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the following claims.