WO2020159762A1

WO2020159762A1 - Methods and apparatus for manufacturing a glass ribbon

Info

Publication number: WO2020159762A1
Application number: PCT/US2020/014516
Authority: WO
Inventors: Bethany Jon ALDERMAN; Shinu BABY; Peter Joseph Lezzi; Yousef Kayed QAROUSH
Original assignee: Corning Incorporated
Priority date: 2019-01-30
Filing date: 2020-01-22
Publication date: 2020-08-06
Also published as: TW202041478A

Abstract

A glass ribbon includes a thickness defined between a first major surface and a second major surface from about 25 µm to about 125 µm. The glass ribbon includes a first compressive stress region extending to a first depth from the first major surface. The glass ribbon includes a second compressive stress region extending to a second depth from the second major surface. The glass ribbon includes an edge extending between the first major surface and the second major surface including an unstressed region extending inwardly from an edge surface. Additionally, methods of manufacturing a glass ribbon are disclosed.

Description

METHODS AND APPARATUS FOR MANUFACTURING A GLASS RIBBON

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Serial No. 62/798546 filed on January 30, 2019, the content of which is relied upon and incorporated herein by reference in its entirety.

FIELD

[0002] The present disclosure relates generally to methods for manufacturing a glass ribbon and, more particularly, to methods for manufacturing a glass ribbon with a compressive stress region.

BACKGROUND

[0003] Glass ribbons can comprise a thickness from about 25 micrometers (pm) to about 125 pm. Forming compressive stress regions within these glass ribbons can lead to buckling, which causes deformation of the glass ribbon. The effects of buckling are most pronounced when a compressive stress along an edge of the glass ribbon exceeds a critical buckling stress of the glass ribbon. Thicker glass ribbons, e.g., greater than 125 pm, can reduce this buckling. However, this thickness range is outside a desired range of thickness (e.g., from about 25 pm to about 125 pm).

[0004] Accordingly, there is a need for a glass ribbon in a thickness range from about 25 pm to about 125 pm with reduced buckling at an edge. Such a glass ribbon comprises with regions of compressive stress of about 100 megapascals (MPa) or more.

SUMMARY

[0005] There is set forth a glass ribbon comprising a first compressive stress region extending to a first depth from a first major surface, and a second compressive stress region extending to a second depth from a second major surface. A first compressive stress of the first compressive stress region and a second compressive stress of the second compressive stress region are each less than a critical buckling stress of the glass ribbon. By forming the first compressive stress and the second compressive stress at less than the critical buckling stress, buckling at an edge of the glass ribbon is reduced.

[0006] Embodiment 1. A glass ribbon comprises a thickness defined between a first major surface and a second major surface from about 25 micrometers (pm or microns) to about 125 pm. The glass ribbon comprises a first compressive stress region extending from the first major surface to a first depth. The glass ribbon comprises a second compressive stress region extending from the second major surface to a second depth. The glass ribbon comprises an edge surface extending between the first major surface and the second major surface comprising an unstressed region extending inwardly from the edge surface.

[0007] Embodiment 2. The glass ribbon of embodiment 1, wherein the first compressive stress region is at a location extending from the edge surface.

[0008] Embodiment 3. The glass ribbon of embodiment 2, wherein a first compressive stress of the first compressive stress region is less than a critical buckling stress of the glass ribbon.

[0009] Embodiment 4. The glass ribbon of any one of embodiments 1-3, wherein the second compressive stress region is at a location extending from the edge surface.

[0010] Embodiment 5. The glass ribbon of embodiment 4, wherein a second compressive stress of the second compressive stress region is less than a critical buckling stress of the glass ribbon.

[0011] Embodiment 6. The glass ribbon of any one of embodiments 1-5, wherein one or more of the first major surface or the second major surface are planar.

[0012] Embodiment 7. A glass ribbon comprising a thickness defined between a first major surface and a second major surface from about 25 pm to about 125 pm. The glass ribbon comprises a first compressive stress region extending from the first major surface to a first depth. The glass ribbon comprises a second compressive stress region extending from the second major surface to a second depth. The glass ribbon comprises a first compressive stress of the first compressive stress region and a second compressive stress of the second compressive stress region are each less than a critical buckling stress of the glass ribbon.

[0013] Embodiment 8. The glass ribbon of embodiment 7, further comprising an edge surface extending between the first major surface and the second major surface comprising an edge compressive stress region extending inwardly from the edge surface to a third depth.

[0014] Embodiment 9. The glass ribbon of embodiment 8, wherein an edge compressive stress of the edge compressive stress region is less than the critical buckling stress of the glass ribbon.

[0015] Embodiment 10. The glass ribbon of any one of embodiments 7-9, wherein one or more of the first major surface or the second major surface are planar.

[0016] Embodiment 11. A method of manufacturing a glass ribbon comprising masking an edge surface of the glass ribbon. The method comprises exposing the glass ribbon to a strengthening bath to form a first compressive stress region at a first major surface of the glass ribbon and a second compressive stress region at a second major surface of the glass ribbon. The method comprises unmasking the edge surface to expose an unstressed region extending inwardly into the glass ribbon from the edge surface.

[0017] Embodiment 12. The method of embodiment 11, wherein the masking comprises applying a coating to the edge surface.

[0018] Embodiment 13. The method of embodiment 12, wherein the unmasking comprises rinsing the coating from the edge surface.

[0019] Embodiment 14. The method of embodiment 11, wherein the masking comprises oversizing the glass ribbon relative to a desired dimension of the glass ribbon, wherein the edge surface is disposed on a perimeter of the desired dimension of the glass ribbon.

[0020] Embodiment 15. The method of embodiment 14, wherein the unmasking comprises removing an edge portion of the oversized glass ribbon to expose the edge surface on the desired dimension of the glass ribbon.

[0021] Embodiment 16. The method of embodiment 15, wherein the unmasking comprises laser cutting the edge portion from the oversized glass ribbon. [0022] Embodiment 17. The method of any one of embodiments 11-16, further comprising cleaning the edge surface after the unmasking.

[0023] Embodiment 18. A method of manufacturing a glass ribbon comprising exposing the glass ribbon to a strengthening bath to form a first compressive stress region at a first major surface of the glass ribbon, a second compressive stress region at a second major surface of the glass ribbon, and an edge compressive stress region extending inwardly from an outer edge surface of the glass ribbon and between the first major surface and the second major surface, wherein a first compressive stress of the first compressive stress region and a second compressive stress of the second compressive stress region are each less than a critical buckling stress of the glass ribbon. The method comprises removing the edge compressive stress region by removing a portion of the edge of the glass ribbon comprising the outer edge surface.

[0024] Embodiment 19. The method of embodiment 18, wherein the removing the edge compressive stress region comprises laser cutting the edge portion from the glass ribbon.

[0025] Embodiment 20. The method of embodiment 19, further comprising cleaning an edge surface of the glass ribbon exposed after the edge portion is removed.

[0026] Additional features and advantages of the embodiments disclosed herein will be set forth in the detailed description that follows, and in part will be clear to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings. It is to be understood that both the foregoing general description and the following detailed description present embodiments intended to provide an overview or framework for understanding the nature and character of the embodiments disclosed herein. The accompanying drawings are included to provide further understanding, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the disclosure, and together with the description explain the principles and operations thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] These and other features, embodiments and advantages are better understood when the following detailed description is read with reference to the accompanying drawings, in which:

[0028] FIG. 1 schematically illustrates example embodiments of a glass manufacturing apparatus in accordance with embodiments of the disclosure;

[0029] FIG. 2 illustrates a perspective cross-sectional view of the glass manufacturing apparatus along line 2-2 of FIG. 1 in accordance with embodiments of the disclosure;

[0030] FIG. 3 illustrates a perspective view of example embodiments of a glass ribbon in accordance with embodiments of the disclosure;

[0031] FIG. 4 illustrates a side view of example embodiments of a glass ribbon along line 4-4 of FIG. 3 in accordance with embodiments of the disclosure;

[0032] FIG. 5 illustrates a side view of example embodiments of a glass ribbon with a coating in accordance with embodiments of the disclosure;

[0033] FIG. 6 illustrates a top view of example embodiments of a glass ribbon with a coating along line 6-6 of FIG. 5 in accordance with embodiments of the disclosure;

[0034] FIG. 7 illustrates a side view of example embodiments of a glass ribbon exposed to a strengthening bath in accordance with embodiments of the disclosure;

[0035] FIG. 8 illustrates a side view of example embodiments of a glass ribbon with the coating partially removed in accordance with embodiments of the disclosure;

[0036] FIG. 9 illustrates a side view of example embodiments of a glass ribbon comprising an oversized dimension in accordance with embodiments of the disclosure;

[0037] FIG. 10 illustrates a top view of example embodiments of a glass ribbon with an oversized dimension along line 10-10 of FIG. 9 in accordance with embodiments of the disclosure;

[0038] FIG. 11 illustrates a side view of example embodiments of a glass ribbon with an oversized dimension exposed to a strengthening bath in accordance with embodiments of the disclosure; [0039] FIG. 12 illustrates a top view of example embodiments of a glass ribbon with an edge surface being unmasked in accordance with embodiments of the disclosure;

[0040] FIG. 13 illustrates a top view of example embodiments of a glass ribbon with edge surfaces removed in accordance with embodiments of the disclosure;

[0041] FIG. 14 illustrates a side view of additional embodiments of a glass ribbon comprising an edge compressive stress region in accordance with embodiments of the disclosure;

[0042] FIG. 15 illustrates a side view of additional embodiments of a glass ribbon with a coating exposed to a strengthening bath in accordance with embodiments of the disclosure;

[0043] FIG. 16 illustrates a side view of additional embodiments of a glass ribbon exposed to a strengthening bath with a first compressive stress region and a second compressive stress region in accordance with embodiments of the disclosure; and

[0044] FIG. 17 illustrates a side view of additional embodiments of a glass ribbon exposed to a strengthening bath with a first compressive stress region, a second compressive stress region, and an edge compressive stress region in accordance with embodiments of the disclosure.

DETAILED DESCRIPTION

[0045] Embodiments will now be described more fully hereinafter with reference to the accompanying drawings in which example embodiments are shown. Whenever possible, the same reference numerals are used throughout the drawings to refer to the same or like parts. However, this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0046] The present disclosure relates to glass manufacturing apparatus and methods for manufacturing glass. Methods and apparatus for manufacturing glass will now be described by way of example embodiments for manufacturing a glass ribbon from a quantity of molten material. As schematically illustrated in FIG. 1, in some embodiments, an exemplary glass manufacturing apparatus 100 can comprise a glass melting and delivery apparatus 102 and a forming apparatus 101 comprising a forming vessel 140 designed to produce a ribbon 103 from a quantity of molten material 121. In some embodiments, the ribbon 103 can comprise a central portion 152 positioned between opposite edge portions (e.g., edge beads) formed along a first outer edge 153 and a second outer edge 155 of the ribbon 103, wherein a thickness of the edge beads can be greater than a thickness of the central portion. Additionally, in some embodiments, a separated glass ribbon 104 can be separated from the ribbon 103 along a separation path 151 by a glass separator 149 (e.g., scribe, score wheel, diamond tip, laser, etc.). In some embodiments, before or after separation of the separated glass ribbon 104 from the ribbon 103, the edge beads formed along the first outer edge 153 and the second outer edge 155 can be removed to provide the central portion 152 as a high-quality separated glass ribbon 104 comprising a uniform thickness.

[0047] In some embodiments, the glass melting and delivery apparatus 102 can comprise a melting vessel 105 oriented to receive batch material 107 from a storage bin 109. The batch material 107 can be introduced by a batch delivery device 111 powered by a motor 113. In some embodiments, an optional controller 115 can be operated to activate the motor 113 to introduce a desired amount of batch material 107 into the melting vessel 105, as indicated by arrow 117. The melting vessel 105 can heat the batch material 107 to provide molten material 121. In some embodiments, a melt probe 119 can be employed to measure a level of molten material 121 within a standpipe 123 and communicate the measured information to the controller 115 by way of a communication line 125.

[0048] Additionally, in some embodiments, the glass melting and delivery apparatus 102 can comprise a first conditioning station comprising a fining vessel 127 located downstream from the melting vessel 105 and coupled to the melting vessel 105 by way of a first connecting conduit 129. In some embodiments, molten material 121 can be gravity fed from the melting vessel 105 to the fining vessel 127 by way of the first connecting conduit 129. For example, in some embodiments, gravity can drive the molten material 121 through an interior pathway of the first connecting conduit 129 from the melting vessel 105 to the fining vessel 127. Additionally, in some embodiments, bubbles can be removed from the molten material 121 within the fining vessel 127 by various techniques.

[0049] In some embodiments, the glass melting and delivery apparatus 102 can further comprise a second conditioning station comprising a mixing chamber 131 that can be located downstream from the fining vessel 127. The mixing chamber 131 can be employed to provide a homogenous composition of molten material 121, thereby reducing or eliminating inhomogeneity that may otherwise exist within the molten material 121 exiting the fining vessel 127. As shown, the fining vessel 127 can be coupled to the mixing chamber 131 by way of a second connecting conduit 135. In some embodiments, molten material 121 can be gravity fed from the fining vessel 127 to the mixing chamber 131 by way of the second connecting conduit 135. For example, in some embodiments, gravity can drive the molten material 121 through an interior pathway of the second connecting conduit 135 from the fining vessel 127 to the mixing chamber 131.

[0050] Additionally, in some embodiments, the glass melting and delivery apparatus 102 can comprise a third conditioning station comprising a delivery vessel 133 that can be located downstream from the mixing chamber 131. In some embodiments, the delivery vessel 133 can condition the molten material 121 to be fed into an inlet conduit 141. For example, the delivery vessel 133 can function as an accumulator and/or flow controller to adjust and provide a consistent flow of molten material 121 to the inlet conduit 141. As shown, the mixing chamber 131 can be coupled to the delivery vessel 133 by way of a third connecting conduit 137. In some embodiments, molten material 121 can be gravity fed from the mixing chamber 131 to the delivery vessel 133 by way of the third connecting conduit 137. For example, in some embodiments, gravity can drive the molten material 121 through an interior pathway of the third connecting conduit 137 from the mixing chamber 131 to the delivery vessel 133. As further illustrated, in some embodiments, a delivery pipe 139 can be positioned to deliver molten material 121 to forming apparatus 101, for example the inlet conduit 141 of the forming vessel 140.

[0051] Forming apparatus 101 can comprise various embodiments of forming vessels in accordance with features of the disclosure comprising a forming vessel with a wedge for fusion drawing the glass ribbon, a forming vessel with a slot to slot draw the glass ribbon, or a forming vessel provided with press rolls to press roll the glass ribbon from the forming vessel. By way of illustration, the forming vessel 140 shown and disclosed below can be provided to fusion draw molten material 121 off a bottom edge, defined as a root 145, of a forming wedge 209 to produce a ribbon of molten material 121 that can be drawn into the ribbon 103. For example, in some embodiments, the molten material 121 can be delivered from the inlet conduit 141 to the forming vessel 140. The molten material 121 can then be formed into the ribbon 103 based, in part, on the structure of the forming vessel 140. For example, as shown, the molten material 121 can be drawn off the bottom edge (e.g., root 145) of the forming vessel 140 along a draw path extending in a draw direction 154 of the glass manufacturing apparatus 100. In some embodiments, edge directors 163, 164 can direct the molten material 121 off the forming vessel 140 and define, in part, a width“W” of the ribbon 103. In some embodiments, the width“W” of the ribbon 103 extends between the first outer edge 153 of the ribbon 103 and the second outer edge 155 of the ribbon 103.

[0052] In some embodiments, the width“W” of the ribbon 103, which extends between the first outer edge 153 of the ribbon 103 and the second outer edge 155 of the ribbon 103, can be greater than or equal to about 20 millimeters (mm), for example, greater than or equal to about 50 mm, for example, greater than or equal to about 100 mm, for example, greater than or equal to about 500 mm, for example, greater than or equal to about 1000 mm, for example, greater than or equal to about 2000 mm, for example, greater than or equal to about 3000 mm, for example, greater than or equal to about 4000 mm, although other widths less than or greater than the widths mentioned above can be provided in further embodiments. For example, in some embodiments, the width“W” of the ribbon 103 can be from about 20 mm to about 4000 mm, for example, from about 50 mm to about 4000 mm, for example, from about 100 mm to about 4000 mm, for example, from about 500 mm to about 4000 mm, for example, from about 1000 mm to about 4000 mm, for example, from about 2000 mm to about 4000 mm, for example, from about 3000 mm to about 4000 mm, for example, from about 20 mm to about 3000 mm, for example, from about 50 mm to about 3000 mm, for example, from about 100 mm to about 3000 mm, for example, from about 500 mm to about 3000 mm, for example, from about 1000 mm to about 3000 mm, for example, from about 2000 mm to about 3000 mm, for example, from about 2000 mm to about 2500 mm, and all ranges and subranges therebetween.

[0053] FIG. 2 shows a cross-sectional perspective view of the forming apparatus 101 (e.g., forming vessel 140) along line 2-2 of FIG. 1. In some embodiments, the forming vessel 140 can comprise a trough 201 oriented to receive the molten material 121 from the inlet conduit 141. For illustrative purposes, cross- hatching of the molten material 121 is removed from FIG. 2 for clarity. The forming vessel 140 can further comprise the forming wedge 209 comprising a pair of downwardly inclined converging surfaces 207, 208 extending between opposed ends 210, 211 (See FIG. 1) of the forming wedge 209. The pair of downwardly inclined converging surfaces 207, 208 of the forming wedge 209 can converge along the draw direction 154 to intersect along the root 145 of the forming vessel 140. A draw plane 213 of the glass manufacturing apparatus 100 can extend through the root 145 along the draw direction 154. In some embodiments, the ribbon 103 can be drawn in the draw direction 154 along the draw plane 213. As shown, the draw plane 213 can bisect the forming wedge 209 through the root 145 although, in some embodiments, the draw plane 213 can extend at other orientations relative to the root 145.

[0054] Additionally, in some embodiments, the molten material 121 can flow in a direction 156 into and along the trough 201 of the forming vessel 140. The molten material 121 can then overflow from the trough 201 by simultaneously flowing over corresponding weirs 203, 204 and downward over the outer surfaces 205, 206 of the corresponding weirs 203, 204. Respective streams of molten material 121 can then flow along the downwardly inclined converging surfaces 207, 208 of the forming wedge 209 to be drawn off the root 145 of the forming vessel 140, where the flows converge and fuse into the ribbon 103. The ribbon 103 of molten material can then be drawn off the root 145 in the draw plane 213 along the draw direction 154. In some embodiments, the ribbon 103 can comprise one or more states of material based on a vertical location along the ribbon 103. For example, at one location, the ribbon 103 can comprise the viscous molten material 121, and at another location, the ribbon 103 can comprise an amorphous solid in a glassy state (e.g., a glass ribbon).

[0055] The ribbon 103 comprises a first major surface 215 and a second major surface 216 facing opposite directions and defining between them a thickness“T” (e.g., average thickness) of the ribbon 103. In some embodiments, the thickness“T’ of the ribbon 103 can be less than or equal to about 2 millimeters (mm), less than or equal to about 1 millimeter, less than or equal to about 0.5 millimeters, for example, less than or equal to about 300 micrometers (pm), less than or equal to about 200 micrometers, or less than or equal to about 100 micrometers, although other thicknesses may be provided in further embodiments. For example, in some embodiments, the thickness “T’ of the ribbon 103 can be from about 25 pm to about 125 pm, from about 50 pm to about 750 pm, from about 100 pm to about 700 pm, from about 200 pm to about 600 pm, from about 300 pm to about 500 pm, from about 50 pm to about 500 pm, from about 50 pm to about 700 pm, from about 50 pm to about 600 pm, from about 50 pm to about 500 pm, from about 50 pm to about 400 pm, from about 50 pm to about 300 pm, from about 50 pm to about 200 pm, from about 50 pm to about 100 pm, including all ranges and subranges of thicknesses therebetween. In addition, the ribbon 103 can include a variety of compositions including, but not limited to, soda-lime glass, borosilicate glass, alumino-borosilicate glass, alkali-containing glass, or alkali-free glass.

[0056] In some embodiments, the glass separator 149 (see FIG. 1) can then separate the glass ribbon 104 from the ribbon 103 along the separation path 151 as the ribbon 103 is formed by the forming vessel 140. As illustrated, in some embodiments, the separation path 151 can extend along the width“W” of the ribbon 103 between the first outer edge 153 and the second outer edge 155. Additionally, in some embodiments, the separation path 151 can extend perpendicular to the draw direction 154 of the ribbon 103. Moreover, in some embodiments, the draw direction 154 can define a direction along which the ribbon 103 can be drawn from the forming vessel 140

[0057] In some embodiments, a plurality of separated glass ribbons 104 can be stacked to form a stack of separated glass ribbons 104. In some embodiments, interleaf material can be placed between an adjacent pair of separated glass ribbons 104 to help prevent contact and therefore preserve the pristine surfaces of the pair of separated glass ribbons 104.

[0058] In further embodiments, although not shown, the ribbon 103 from the glass manufacturing apparatus may be coiled onto a storage roll. Once a desired length of coiled ribbon is stored on the storage roll, the ribbon 103 may be separated by the glass separator 149 such that the separated glass ribbon is stored on the storage roll. In further embodiments, a separated glass ribbon can be separated into another separated glass ribbon. For example, a separated glass ribbon 104 (e.g., from the stack of glass ribbons) can be further separated into another separated glass ribbon. In further embodiments, a separated glass ribbon stored on a storage roll can be uncoiled and further separated into another separated glass ribbon.

[0059] The separated glass ribbon can then be processed into a desired application, e.g., a display application. For example, the separated glass ribbon can be used in a wide range of display applications, including liquid crystal displays (LCDs), electrophoretic displays (EPD), organic light emitting diode displays (OLEDs), plasma display panels (PDPs), and other electronic displays.

[0060] Referring to FIG. 3, a perspective view of the glass ribbon 104 is illustrated. The glass ribbon 104 can comprise the first major surface 215 and the second major surface 216. In some embodiments, one or more of the first major surface 215 or the second major surface 216 may be planar. For example, the first major surface

215 and the second major surface 216 may be planar, and, in some embodiments, the first major surface 215 may be parallel to the second major surface 216. A thickness 301 can be defined between the first major surface 215 and the second major surface

216 from about 25 micrometers (pm) to about 125 pm. In some embodiments, the thickness 301 may be from about 50 pm to about 100 pm. In some embodiments, the thickness 301 may be from about 60 pm to about 80 pm. In some embodiments, the glass ribbon 104 can comprise an edge 303 extending between the first major surface 215 and the second major surface 216. The edge 303 can be defined at an outermost perimeter of the glass ribbon 104, and may extend about a border of the glass ribbon 104 [0061] In some embodiments, the glass ribbon 104 can comprise one or more of an alkali-free aluminosilicate, borosilicate, boroaluminosilicate, or silicate glass composition. In some embodiments, the glass ribbon 104 can comprise alkali- containing aluminosilicate, borosilicate, boroaluminosilicate, or silicate glass compositions. In some embodiments, alkaline earth modifiers can be added to any of the foregoing compositions for the glass ribbon 104. In some embodiments, the glass ribbon 104 can comprise one or more of the following glass compositions: S1O2 from about 64% to about 69% (by mol%), AI2O3 from about 5% to about 12%, B2O3 from about 8% to about 23%, MgO from about 0.5% to about 2.5%, CaO from about 1% to about 9%, SrO from about 0% to about 5%, BaO from about 0% to about 5%, SnCh from about 0.1% to about 0.4%, ZrCh from about 0% to about 0.1%, or Na₂0 from about 1% to about 1%. In some embodiments, the glass ribbon 104 can comprise one or more of the following glass compositions: S1O2 at about 67.4% (by mol%), AI2O3 at about 12.7%, B2O3 at about 3.7%, MgO at about 2.4%, CaO at about 0%, SrO at about 0%, Sn0₂ at about 0.1%, or Na₂0 at about 13.7%. In some embodiments, the glass ribbon 104 can comprise an elastic modulus that facilitates bending, as generally reducing elastic modulus of the glass ribbon will reduce tensile stress during bending.

[0062] Referring to FIG. 4, a side view of the glass ribbon 104 is illustrated along lines 4-4 of FIG. 3. In some embodiments, the glass ribbon 104 comprises a first compressive stress region 401 extending from the first major surface 215 to a first depth 403. In some embodiments, the first compressive stress region 401 can be located within the glass ribbon 104 to offset tensile stresses generated in the glass ribbon 104 during bending, wherein the tensile stresses may reach a maximum near a surface, for example, the first major surface 215. In some embodiments, the first compressive stress region 401 may be at a location extending from the edge 303. For example, the first compressive stress region 401 can extend to the first depth 403 from the edge 303 of the glass ribbon 104, and may also extend to the first depth 403 at a central region (e.g., inward from the edge 303) of the glass ribbon 104 from the first major surface 215. In some embodiments, a first compressive stress of the first compressive stress region 401 may be less than a critical buckling stress of the glass ribbon 104. For example, the first compressive stress of the first compressive stress region 401 may be about 100 megapascals (MPa) or more. In some embodiments, the first compressive stress of the first compressive stress region 401 may be from about 600 MPa to about 1500 MPa. In some embodiments, the first compressive stress of the first compressive stress region 401 may be from about 1100 MPa to about 1300 MPa.

[0063] In some embodiments, the first depth 403 to which the first compressive stress region 401 extends from the first major surface 215 can be from about 5 micrometers (pm) to about 25 pm. In some embodiments, the first depth 403 can depend on the thickness 301 of the glass ribbon 104. For instance, in some embodiments, the first depth 403 can be from about 0.1 to about 0.3 times the thickness 301. For example, in some embodiments, when the thickness 301 of the glass ribbon 104 is about 50 pm, the first depth 403 can be from about 5 pm to about 15 pm. In some embodiments, when the thickness 301 of the glass ribbon 104 is greater than about 50 pm, the first depth 403 can likewise be greater than about 15 pm. For example, in some embodiments, when the thickness 301 of the glass ribbon 104 is about 100 pm, then the first depth 403 can be from about 10 pm to about 30 pm, or about 15 pm to about 25 pm. In some embodiments, the first depth 403 may be substantially constant across the first major surface 215 of the glass ribbon 104. For example, the first depth 403 at the edge 303 may be substantially the same as the first depth 403 at a central location of the glass ribbon 104. However, in other embodiments, the glass ribbon 104 is not so limited, and the first depth 403 may be non-constant across the first major surface 215 of the glass ribbon 104. For example, at one or more locations, the first depth 403 may be different than the first depth 403 at other locations across the first major surface 215.

[0064] In some embodiments, the glass ribbon 104 can comprise a second compressive stress region 407 extending from the second major surface 216 to a second depth 409. In some embodiments, the second compressive stress region 407 can be located within the glass ribbon 104 to offset tensile stresses generated in the glass ribbon 104 during bending, wherein the tensile stresses may reach a maximum near a surface of the glass ribbon, for example, the second major surface 216. In some embodiments, the second compressive stress region 407 may be at a location extending from the edge 303. For example, the second compressive stress region 407 can extend to the second depth 409 from the edge 303 of the glass ribbon 104, and may also extend from the second major surface 216 to the second depth 409 at a central region (e.g., inward from the edge 303) of the glass ribbon 104. In some embodiments, a second compressive stress of the second compressive stress region 407 may be less than a critical buckling stress of the glass ribbon 104. For example, the second compressive stress of the second compressive stress region 407 may be about 100 megapascals (MPa) or more. In some embodiments, the second compressive stress of the second compressive stress region 407 may be from about 600 MPa to about 1500 MPa. In some embodiments, the second compressive stress of the second compressive stress region 407 may be from about 1100 MPa to about 1300 MPa. In some embodiments, the first compressive stress of the first compressive stress region 401 and the second compressive stress of the second compressive stress region 407 may each be less than the critical buckling stress of the glass ribbon 104.

[0065] In some embodiments, the second depth 409 to which the second compressive stress region 407 extends from the second major surface 216 can be from about 5 micrometers (pm) to about 25 pm. For instance, in some embodiments, the second depth 409 can be from about 0.1 to about 0.3 times the thickness 301. For example, in some embodiments, when the thickness 301 of the glass ribbon 104 is about 50 pm, the second depth 409 can be from about 5 pm to about 15 pm. In some embodiments, when the thickness 301 of the glass ribbon 104 is greater than 50 pm, the second depth 409 can likewise be greater than about 15 pm. For example, in some embodiments, when the thickness 301 of the glass ribbon 104 is about 100 pm, the second depth 409 can be from about 10 pm to about 30 pm, or about 15 pm to about 25 pm. In some embodiments, the second depth 409 may be substantially constant across the second major surface 216 of the glass ribbon 104. For example, the second depth 409 at the edge 303 may be substantially the same as the second depth 409 at a central location of the glass ribbon 104. However, in other embodiments, the glass ribbon 104 is not so limited, and the second depth 409 may be non-constant across the second major surface 216 of the glass ribbon 104. For example, at one or more locations, the second depth 409 may be different than the second depth 409 at other locations across the second major surface 216. In some embodiments, the second depth 409 is substantially equal to the first depth 407.

[0066] In some embodiments, the edge 303 can comprise an unstressed region 413 extending inwardly from at least a portion of an edge surface 415. For example, a compressive stress of the unstressed region 413 may be zero. In this way, the compressive stress of the unstressed region 413 may be less than the first compressive stress of the first compressive stress region 401 and may be less than the second compressive stress of the second compressive stress region 407. In some embodiments, the unstressed region 413 can extend from the edge surface 415 of the edge 303 inwardly towards a bulk interior of the glass ribbon 104. In some embodiments, the unstressed region 413 of the edge 303 can be located at a center of the edge 303 and may extend inwardly from the edge surface 415 towards a bulk interior of the glass ribbon 104. For example, the first compressive stress region 401 may extend from the first major surface 215 to the first depth 403 at a first end 417 of the edge 303. The second compressive stress region 407 may extend from the second major surface 216 to the second depth 409 at a second end 419 of the edge 303. In some embodiments, a central region 421 of the glass ribbon 104 may exist between the first compressive stress region 401 and the second compressive stress region 407. The central region 421 may comprise the unstressed region 413 of the edge 303, such that the unstressed region 413 of the edge 303 can be located between the first compressive stress region 401 and the second compressive stress region 407.

[0067] Referring to FIGS. 5-13, example embodiments of methods of manufacturing the glass ribbon 104 are illustrated. Referring to FIG. 5, methods of manufacturing the glass ribbon 104 can comprise masking the edge surface 415 of the edge 303 of the glass ribbon 104 prior to exposing the glass ribbon 104 to a strengthening bath. In some embodiments, to generate compressive stress regions on less than all surfaces of the glass ribbon 104, portions of the glass ribbon 104 can be masked prior to exposing the glass ribbon 104 to the strengthening bath. For example, it may be desirable for the glass ribbon 104 to comprise the first compressive stress region 401 extending from the first major surface 215 and the second compressive stress region 407 extending from the second major surface 216, but for other surfaces of the glass ribbon 104 to comprise unstressed regions, for example, the unstressed region 413 of the edge 303. In some embodiments, the edge 303 of the glass ribbon 104 can be masked. In some embodiments, the edge surface 415 of the glass ribbon 104 can be masked while the first major surface 215 and the second major surface 216 can remain unmasked. For example, the masking the edge surface 415 can comprise applying a coating 501 to the edge surface 415.

[0068] FIG. 6 illustrates a top view of the glass ribbon 104 as viewed along lines 6-6 of FIG. 5. In some embodiments, all the edge surfaces 415 can be masked with the coating 501. In this way, the edge surface 415 can be masked (e.g., covered, sheltered, shielded, etc.) while the first major surface 215 and the second major surface 216 can remain unmasked (e.g., exposed). The coating 501 can comprise a material that can be impervious to the strengthening bath, such that when the glass ribbon 104 and the coating 501 are exposed to the strengthening bath, the coating 501 can remain on the edge surface 415. In this way, the coating 501 can mask the edge surface 415 from the strengthening bath and limit the strengthening bath from contacting the edge surface 415. In some embodiments, the coating 501 can comprise an ink, for example organic and/or non-organic inks used for automotive applications with permeable to semi-permeable surfaces, a calcium-based material, etc. The coating 501 can be applied in several ways, for example, by lamination, screen printing, etc.

[0069] Referring to FIG. 7, methods of manufacturing the glass ribbon 104 can comprise exposing the glass ribbon 104 to a strengthening bath 701 to form the first compressive stress region 401 extending from the first major surface 215 of the glass ribbon 104 and the second compressive stress region 407 extending from the second major surface 216 of the glass ribbon 104. In some embodiments, exposing the glass ribbon 104 to the strengthening bath 701 can form the first compressive stress region 401 and the second compressive stress region 407 through an ion exchange process. For example, the first compressive stress region 401 and the second compressive stress region 407 can comprise a plurality of ion-exchangeable ions and a plurality of ion- exchanged ions. The ion-exchanged ions can be selected to produce the first compressive stress in the first compressive stress region 401 and the second compressive stress in the second compressive stress region 407. In some embodiments, the ion-exchanged ions can have an atomic radius that can be larger than the atomic radius of the ion-exchangeable ions. For example, the ion-exchangeable ions (e.g., Na⁺ ions) may be present in the glass ribbon 104 prior to the glass ribbon 104 being exposed to the strengthening bath and, thus, an ion exchange process. Ion-exchanging ions (e.g., K⁺ ions) may be incorporated into the glass ribbon 104 to replace some of the ion- exchangeable ions.

[0070] The incorporation of the ion-exchanging ions (e.g., K⁺ ions) into the first major surface 215 and the second major surface 216 of the glass ribbon 104 may be produced by submerging the glass ribbon 104 into the strengthening bath 701. In some embodiments, the strengthening bath 701 may comprise a molten salt bath containing ion-exchanging ions (e.g., molten KNO3 salt). The ion-exchanging ions (e.g., K⁺ ions) may have a larger atomic radius than the ion-exchangeable ions (e.g., Na⁺ ions), which can generate compressive stresses within the glass ribbon 104, for example, at the first compressive stress region 401 and the second compressive stress region 407. In some embodiments, the glass ribbon 104 can be exposed to the strengthening bath 701 from about 6 hours to about 8 hours, with the strengthening bath 701 maintained at a temperature from about 350° Celsius (°C) to about 450°C.

[0071] Depending on the amount of time the glass ribbon 104 is exposed to the strengthening bath 701, the first depth 403 of the first compressive stress region 401 and the second depth 409 of the second compressive stress region 407 can be controlled. For example, a general trend is that as the glass ribbon 104 is exposed to the strengthening bath 701 for longer times, the first depth 403 of the first compressive stress region 401 from the first major surface 215 and the second depth 409 of the second compressive stress region 407 from the second major surface 216 become larger, for a given bath temperature and composition. In contrast, another general trend is that when the glass ribbon 104 is exposed to the strengthening bath 701 for shorter times, the first depth 403 of the first compressive stress region 401 from the first major surface 215 and the second depth 409 of the second compressive stress region 407 from the second major surface 216 become smaller, for a given bath temperature and composition. For example, a longer time may be about 8 hours or more, and a shorter time may be about 6 hours or less. [0072] In some embodiments, the coating 501 can be capable of withstanding the strengthening bath 701 and limiting the strengthening bath 701 from contacting the edge surface 415. For example, the coating 501 can withstand the high temperature of the strengthening bath 701 (e.g., from about 350° Celsius (°C) to about 450°C, for example), along with the material of the strengthening bath (e.g., 100% KNO3, for example) for the time that the glass ribbon 104 is immersed in the strengthening bath 701 (e.g., from about 6 hours to about 8 hours, for example). During this time, the coating 501 can remain on the edge surface 415, thus shielding the edge surface 415 while allowing for the first compressive stress region 401 to be generated at a location extending from the first major surface 215 and the second compressive stress region 407 to be generated at a location extending from the second major surface 216. Since the coating 501 limits the strengthening bath 701 from contacting the edge surface 415, a compressive stress region can be limited from forming at a location extending from the edge surface 415 of the glass ribbon 104, thus allowing for the unstressed region 413 to be present at the edge 303.

[0073] Referring to FIG. 8, in some embodiments, methods of manufacturing the glass ribbon 104 can comprise unmasking the edge surface 415 to expose the unstressed region 413 extending into the glass ribbon 104 from the unmasked portion of the edge surface 415. For example, unmasking the edge surface 415 can comprise rinsing the coating 501 from the edge surface 415. For example, a liquid can be directed along a direction 801 towards the coating 501 to remove the coating 501 from the edge surface 415. In some embodiments, a pressurized liquid can be directed at a velocity sufficient to cause the coating 501 to be removed from the edge surface 415. In other embodiments, a stripping solution can be applied to the coating 501 to remove the coating from the edge surface 415. Once the edge surface 415 has been unmasked by removing the coating 501 and unmasking the edge surface 415, the unstressed region 413 that extends inwardly from the unmasked portion of the edge surface 415 can be exposed. The glass ribbon 104 can therefore comprise the first compressive stress region 401 extending from the first major surface 215, the second compressive stress region 407 extending from the second major surface 216, and the unstressed region 413 at the edge 303. [0074] Referring to FIG. 9, further embodiments of methods of manufacturing the glass ribbon 104 are illustrated. In some embodiments, methods of manufacturing the glass ribbon 104 can comprise masking the edge surface 415 of the glass ribbon 104 prior to exposing the glass ribbon 104 to the strengthening bath 701. For example, masking the edge surface 415 can comprise oversizing the glass ribbon 104 relative to a desired dimension 903 of the glass ribbon 104, wherein the edge surface 415 is disposed on a perimeter 901 of the desired dimension of the glass ribbon 104. In some embodiments, the desired dimension 903 of the glass ribbon 104 may comprise a desired length and a desired width of the glass ribbon 104. An oversized dimension 905 of the glass ribbon 104 may comprise an oversized length and an oversized width of the glass ribbon 104. In some embodiments, the oversized dimension 905 of the glass ribbon 104 may be larger than the desired dimension 903 of the glass ribbon 104, wherein the oversized length can be larger than the desired length, and the oversized width can be larger than the desired width. In some embodiments, to generate compressive stress regions on less than all the glass ribbon 104, portions of the glass ribbon 104 can be oversized prior to exposing the glass ribbon 104 to the strengthening bath. For example, it may be desirable for the glass ribbon 104 to comprise the first compressive stress region 401 extending from the first major surface 215 and the second compressive stress region 407 extending from the second major surface 216, but for other surfaces of the glass ribbon 104 to comprise unstressed regions, for example, the unstressed region 413 of the edge 303. By oversizing the glass ribbon 104 relative to the desired dimension 903, the edge 303 of the glass ribbon 104 may be masked.

[0075] FIG. 10 illustrates a top view of the glass ribbon 104 as viewed along lines 10-10 of FIG. 9. In some embodiments, all the edge surfaces 415 can be masked with the oversized glass ribbon 104. In this way, the edge surfaces 415 can be masked (e.g., (e.g., covered, sheltered, shielded, etc.) while the first major surface 215 and the second major surface 216 can remain unmasked (e.g., exposed). In some embodiments, only some, or less than all, the edge surfaces 415 may be masked. Oversized edges 1001 of the oversized glass ribbon 104 can be exposed to the strengthening bath 701, such that compressive stress regions can be formed at the oversized edges 1001 of the glass ribbon 104 when the glass ribbon 104 is exposed to the strengthening bath 701. [0076] Referring to FIG. 11, methods of manufacturing the glass ribbon 104 can comprise exposing the glass ribbon 104 to the strengthening bath 701 to form the first compressive stress region 401 extending from the first major surface 215 of the glass ribbon 104 and the second compressive stress region 407 extending from the second major surface 216 of the glass ribbon 104. The strengthening bath 701 can be substantially similar in material composition and temperature as described relative to FIG. 7, with the duration over which the glass ribbon 104 can be exposed to the strengthening bath 701 being substantially the same. In some embodiments, exposing the glass ribbon 104 to the strengthening bath 701 can form the first compressive stress region 401 and the second compressive stress region 407 through the ion exchange process. In some embodiments, since the oversized edges 1001 of the glass ribbon 104 are exposed to the strengthening bath 701, compressive stress regions can be formed at the oversized edges 1001 due to exposure to the strengthening bath 701. As such, in some embodiments, methods of manufacturing the glass ribbon 104 can comprise exposing the glass ribbon 104 to the strengthening bath 701 to form the first compressive stress region 401 extending from the first major surface 215 of the glass ribbon 104, the second compressive stress region 407 extending from the second major surface 216 of the glass ribbon 104, and an edge compressive stress region 1101 at an outer edge surface 1103 of the glass ribbon 104 extending inwardly from the outer edge surface 1103 and between the first major surface 215 and the second major surface 216, wherein the first compressive stress of the first compressive stress region 401 and the second compressive stress of the second compressive stress region 407 are each less than a critical buckling stress of the glass ribbon 104.

[0077] Referring to FIG. 12, in some embodiments, methods of manufacturing the glass ribbon 104 can comprise unmasking the edge surface 415 to expose the unstressed region 413 extending into the glass ribbon 104 inwardly from the unmasked portion of the edge surface 415. For example, unmasking the edge surface 415 can comprise removing an edge portion 1201 from the oversized glass ribbon 104 to expose the edge surface 415 on the desired dimension 903 of the glass ribbon 104. In some embodiments, unmasking the edge surface 415 can comprise laser cutting the edge portion 1201 of the glass ribbon 104 to expose the edge surface 415. For example, a laser 1203 can laser cut the edge portion 1201 to separate the edge portion 1201 from the glass ribbon 104. In some embodiments, the laser 1203 can comprise a CO2 laser, a CO laser, a Bessel beam laser, etc. In some embodiments, methods of manufacturing the glass ribbon 104 can comprise removing the edge compressive stress region 1101 by removing the edge portion 1201 of the glass ribbon 104 comprising the outer edge surface 1103. In some embodiments, removing the edge compressive stress region 1101 can comprise laser cutting the edge portion 1201 from the glass ribbon 104.

[0078] Referring to FIG. 13, methods of manufacturing the glass ribbon 104 can comprise cleaning the edge surface 415 after unmasking the edge surface 415. For example, with the edge portions 1201 removed, the edge surface 415 on the desired dimension 903 of the glass ribbon 104 may be exposed and cleaned. In some embodiments, the edge surface 415 can be cleaned with a liquid, for example, deionized water. In some embodiments, cleaning the edge surface 415 can comprise a final etching of the glass ribbon 104. For example, the glass ribbon 104 can be exposed to an etching solution comprising 15 vol% HF and 15 vol% HCL. By controlling etching time and/or etching solution, defects on surfaces of the glass ribbon 104, for example, defects on the edge surface 415, can be removed.

[0079] Referring to FIG. 14, further embodiments of a glass ribbon 1401 are illustrated. In the embodiments illustrated and described relative to FIGS. 3-13, the edge 303 of the glass ribbon 104 comprised the unstressed region 413 extending from the edge surface 415. As illustrated in FIG. 14, in some embodiments, the edge 303 of the glass ribbon 1401 may comprise a compressive stress region. For example, the glass ribbon 1401 may be similar to the glass ribbon 104, for example, by comprising the first major surface 215, the second major surface 216, the first compressive stress region 401, the second compressive stress region 407, etc. While the glass ribbon 104 illustrated in FIGS. 3-13 comprises the unstressed region 413 at the edge 303, in some embodiments, the glass ribbon 1401 may comprise an edge compressive stress region 1403. For example, the edge 303 can comprise the edge compressive stress region 1403 extending inwardly from the edge surface 415 to a third depth 1405. In some embodiments, the glass ribbon 1401 comprises four edges, wherein each of the four edges comprises an edge compressive stress region (e.g., edge compressive stress region 1403).

[0080] In some embodiments, the edge compressive stress region 1403 can extend inwardly from the edge surface 415 to the third depth 1405 within an interior of the glass ribbon 1401. The third depth of the edge compressive stress region 1403 may be substantially constant along the length of the edge 303 between the first major surface 215 and the second major surface 216. For example, the edge compressive stress region 1403 can extend to the third depth 1405 at a central region of the edge 303 (e.g., midway between the first major surface 215 and the second major surface 216), while also extending inwardly from the edge surface 415 to the third depth 1405 at locations closer to the first major surface 215 and the second major surface 216. In some embodiments, the third depth 1405 to which the edge compressive stress region 1403 extends inwardly from the edge surface 415 can be from about 5 micrometers (pm) to about 25 pm. In some embodiments, an edge compressive stress of the edge compressive stress region 1403 may be about 100 megapascals (MPa) or more. In some embodiments, the edge compressive stress of the edge compressive stress region 1403 may be from about 600 MPa to about 1500 MPa. In some embodiments, the edge compressive stress of the edge compressive stress region 1403 may be from about 1100 MPa to about 1300 MPa. In some embodiments, the edge compressive stress of the edge compressive stress region 1403 may be less than a critical buckling stress of the glass ribbon 1401.

[0081] Buckling can occur in the glass ribbon 104, 1401 as a result of relatively high compressive stresses, for example, when the compressive stress exceeds a critical buckling stress. When the compressive stress of the glass ribbon 104, 1401 exceeds the critical buckling stress, deformation in the form of buckling can be present near edges of the glass ribbon 104, 1401. In some embodiments, a critical buckling stress of the glass ribbon 104, 1401 can be represented by the equation: s (k)Q²)(E)

(12)(1— v²)(t)² where s_V represents the critical buckling stress of the glass ribbon 104, 1401, E is Young’s modulus of the glass ribbon 104, 1401, v is the Poisson’s ratio of the glass ribbon 104, 1401 (e.g., wherein v may be from about 0.2 to about 0.3), b is a width of the glass ribbon 104, 1401, t is a thickness of the glass ribbon 104, 1401, and k is a buckling coefficient (or loading contribution) of the glass ribbon 104, 1401. In some embodiments, the buckling coefficient (k) of the glass ribbon 104, 1401 can be from about 0.43 to about 6.97, or from about 1.27 to about 4. In some embodiments, the buckling coefficient (k) may be about 4, for hinged-hinged embodiments. In hinged- hinged embodiments, the glass ribbon 104, 1401 is, or is modeled as, supported at opposing locations at a bottom of the glass ribbon 104, 1401 (e.g., similar to a plate that is simply supported at opposing edges). In some embodiments, the buckling coefficient (k) may be about 6.97 for fixed-fixed embodiments. In fixed-fixed embodiments, the glass ribbon 104, 1401 is, or is modeled as, fixed at each end in a cantilevered manner (e.g., similar to a plate in which both edges are cantilevered). In some embodiments, the buckling coefficient (k) may be about 1.27 for hinged-free embodiments. In hinged- free embodiments, the glass ribbon 104, 1401 is, or is modeled to be, supported at one end at a bottom of the glass ribbon 104, 1401 while an opposing end of the glass ribbon 104, 1401 is free and unsupported (e.g., similar to a plate in which one side is simply supported and the other side is free). In some embodiments, the buckling coefficient (k) may be about 0.43 for fixed-free embodiments. In fixed-free embodiments, the glass ribbon 104, 1401 is, or is modeled to be, fixed at one end while an opposing end of the glass ribbon 104, 1401 is free and unsupported (e.g., similar to a plate in which one edge is cantilevered and the other is free). In some embodiments, a geometric

b

contribution to the critical buckling stress (o_c) is represented by (-) while a material property contribution to the critical buckling stress (o_c) is represented by Iⁿ

this way, the critical bucking stress may be based, in part, on the stiffness of the glass ribbon 104, 1401 and/or dimensions of the glass ribbon 104, 1401. In some embodiments, to resist buckling of the glass ribbon 104, 1401, the critical buckling stress can be increased by changing one or more of the loading, material properties, or geometry of the glass ribbon 104, 1401. For example, in some embodiments, as the thickness of the glass ribbon 104, 1401 is increased, the critical buckling stress may also increase, thus allowing for greater compressive stresses to be achieved in the glass ribbon 104, 1401 while not exceeding the critical bucking stress. In addition or in the alternative, reducing the compressive stresses or the depths of the first compressive stress region 401, the second compressive stress region 407, and/or the edge compressive stress region 1403, can also reduce the likelihood of buckling due to the compressive stresses of the glass ribbon 104, 1401 being below the critical buckling stress.

[0082] Providing a compressive stress region at a location extending from the edge 303 of the glass ribbon 1401 in addition to the first major surface 215 and the second major surface 216 while minimizing unwanted buckling of the glass ribbon 1401 can be achieved in several ways. For example, initially, the glass ribbon 1401 may be unstressed, for example, by initially not comprising the first compressive stress region 401, the second compressive stress region 407, and/or the edge compressive stress region 1403. An initial thickness of the glass ribbon 1401 may be relatively larger than the thickness of the glass ribbon 104 of FIGS. 3-13. For example, the thickness 301 of the glass ribbon 1401, which can be defined between the first major surface 215 and the second major surface 216, can be from about 100 micrometers (pm) to about 125 pm. The glass ribbon 1401 can then be exposed to the strengthening bath 701, whereupon the first compressive stress region 401, the second compressive stress region 407, and the edge compressive stress region 1403 can be formed. Due to the thickness 301 of the glass ribbon 1401, the likelihood of the compressive stresses within the glass ribbon 104 exceeding the critical buckling stress may be reduced, thus reducing the likelihood of buckling at the edge 303 of the glass ribbon 1401.

[0083] In some embodiments, the glass ribbon 1401 is not limited to comprising the larger thickness (for example 100 pm to 125 pm) while comprising the edge compressive stress region 1403. For example, in some embodiments, the edge compressive stress region 1403 can be formed in the glass ribbon 1401 comprising the thickness 301 that can be from about 25 pm to about 125 pm while still minimizing buckling at the edge 303. To reduce buckling at the edge 303 in some embodiments, the glass ribbon 1401 can be exposed to the strengthening bath 701 for a shorter time. For example, the glass ribbon 104 illustrated in FIG. 7 may be exposed to the strengthening bath 701 from about 6 hours to about 8 hours, with the strengthening bath 701 maintained at a temperature from about 350° Celsius (°C) to about 450°C. In some embodiments, the glass ribbon 1401 can be exposed to the strengthening bath 701 for a shorter time, for example, from about 1 hour to about 4 hours while maintaining the chemistry and temperature of the strengthening bath 701. By exposing the glass ribbon 1401 to the strengthening bath 701 for a shorter time, the depths of the compressive stress regions in the glass ribbon 1401 may be reduced. For example, when the thickness 301 of the glass ribbon 1401 is about 50 pm, the first depth 403 of the first compressive stress region 401 can be less than about 5 pm. In some embodiments, when the thickness 301 of the glass ribbon 1401 is about 100 pm, the first depth 403 of the first compressive stress region 401 can be less than about 15 pm. Similarly, in some embodiments, when the thickness 301 of the glass ribbon 1401 is about 50 pm, the second depth 409 of the second compressive stress region 407 can be less than about 5 pm. In some embodiments, when the thickness 301 of the glass ribbon 1401 is about 100 pm, the second depth 409 of the second compressive stress region 407 can be less than about 15 pm. In some embodiments, when the thickness 301 of the glass ribbon 1401 is about 50 pm, the third depth 1405 of the edge compressive stress region 1403 can be less than about 5 pm. In some embodiments, when the thickness 301 of the glass ribbon 1401 is about 100 pm, the third depth 1405 of the edge compressive stress region 1403 can be less than about 15 pm. By reducing the time that the glass ribbon 1401 is exposed to the strengthening bath 701, the depths 403, 409, 1405 of the compressive stress regions 401, 407, 1403, may correspondingly be reduced, which can reduce the likelihood of buckling at the edge 303 of the glass ribbon 1401 due to the compressive stresses being lower than the critical buckling stress.

[0084] In some embodiments, the glass ribbon 1401 is not limited to being exposed to the strengthening bath 701 for a reduced time. Rather, in some embodiments, to reduce buckling at the edge 303, the chemistry of the strengthening bath 701 can be changed such that the compressive stress of the compressive stress regions 401, 407, 1403 may be reduced. For example, in some embodiments, the glass ribbon 1401 can be exposed to the strengthening bath 701 from about 6 hours to about 8 hours, with the strengthening bath 701 maintained at a temperature from about 350° Celsius (°C) to about 450°C. In the embodiments of FIG. 7, the strengthening bath 701 may comprise a bath containing ion-exchanging ions, for example, such as about 100% potassium nitrate (KNO3). In some embodiments, some of the KNO3 can be replaced with sodium (Na), which can affect the compressive stress formed in the glass ribbon 1401. For example, in some embodiments, the strengthening bath 701 can comprise from about 70% KNO3 to about 90% KNO3, and may comprise from about 10% Na to about 30% Na. In some embodiments, the strengthening bath 701 can comprise about 80% KNO3 and about 20% Na. By replacing some of the volume of potassium nitrate (KNO3) of the strengthening bath 701 with sodium (Na), the surface compressive stresses generated in the glass ribbon 1401 can be reduced while generating a larger depth of the compressive stress regions. For example, when the thickness 301 of the glass ribbon 1401 is about 50 micrometers (pm), the first depth 403 of the first compressive stress region 401 can be from about 5 pm to about 15 pm, and when the thickness 301 of the glass ribbon 1401 is about 100 pm, the first depth 403 of the first compressive stress region 401 can be from about 15 pm to about 25 pm. Similarly, when the thickness 301 of the glass ribbon 1401 is about 50 pm, the second depth 409 of the second compressive stress region 407 can be from about 5 pm to about 15 pm, and when the thickness 301 of the glass ribbon 1401 is about 100 pm, the second depth 409 of the second compressive stress region 407 can be from about 15 pm to about 25 pm. When the thickness 301 of the glass ribbon 1401 is about 50 pm, the third depth 1405 of the edge compressive stress region 1403 can be from about 5 pm to about 15 pm, and when the thickness 301 of the glass ribbon 1401 is about 100 pm, the third depth 1405 of the edge compressive stress region 1403 can be from about 15 pm to about 25 pm. By reducing the compressive stress of the compressive stress regions 401, 407, 1403 due to changing the chemistry of the strengthening bath 701, the likelihood of buckling at the edge 303 of the glass ribbon 1401 may also be reduced due to the compressive stresses being lower than the critical buckling stress.

[0085] Referring to FIG. 15, in some embodiments, a coating 1501 can be applied to the edge surface 415 of the glass ribbon 1401 prior to exposing the glass ribbon 1401 to the strengthening bath 701. In some embodiments, the coating 1501 can comprise a material that may be semi-impervious to the strengthening bath 701, such that when the glass ribbon 1401 and the coating 1501 are exposed to the strengthening bath 701, the coating 1501 can remain on the edge surface 415 for a time. During this time, the edge surface 415 may not be exposed to the strengthening bath 701, and a compressive stress region (e.g., edge compressive stress region 1403) may not be formed. After the time has passed, the coating 1501 may be removed from the edge surface 415, for example, due to the coating 1501 being exposed to the strengthening bath 701. With the coating 1501 removed from the edge surface 415, the edge compressive stress region 1403 may be formed due to the exposure of the edge surface 415 to the strengthening bath 701. Initially, as illustrated in FIG. 15, the edge surface 415 may be masked or covered by the coating 1501, while the first major surface 215 and the second major surface 216 may not be masked or covered by the coating 1501. As such, initially, the first major surface 215 and the second major surface 216 may be exposed to the strengthening bath 701 while the edge surface 415 may not be exposed to the strengthening bath 701. In some embodiments, the coating 1501 may comprise a silane-containing material, for example, fluoro- or perfluorosilanes (e.g., alkylsilanes).

[0086] Referring to FIG. 16, the glass ribbon 1401 and the coating 1501 can be exposed to the strengthening bath 701 for a time. During this time, due to the exposure of the first major surface 215 and the second major surface 216 to the strengthening bath 701, the first compressive stress region 401 can be formed at a location extending from the first major surface 215 and the second compressive stress region 407 can be formed at a location extending from the second major surface 216. In some embodiments, the first compressive stress region 401 can extend from the first major surface 215 to a first intermediate depth 1601 while the second compressive stress region 407 can extend from the second major surface 216 to a second intermediate depth 1603. The first intermediate depth 1601 may be less than the first depth 403 and the second intermediate depth 1603 may be less than the second depth 409 due to the glass ribbon 1401 being exposed to the strengthening bath 701 for a time that can be less than the full period of exposure, which can be from about 6 hours to about 8 hours. During the exposure of the coating 1501 to the strengthening bath 701, a thickness of the coating 1501 can be reduced. For example, the coating 1501 may be exposed to the chemistry and increased heat of the strengthening bath 701 for a time which can cause the coating 1501, or portions thereof, to be removed from the edge surface 415 and reduced in thickness. However, with the coating 1501 still masking the edge surface 415 despite the reduced thickness, the edge compressive stress region 1403 may not be formed at a location extending from the edge surface 415. In some embodiments, the coating 1501 can remain on the edge surface 415 for less than the full time that the glass ribbon 1401 can be exposed to the strengthening bath 701 (e.g., from about 6 hours to about 8 hours). For example, in some embodiments, the coating 1501 can remain on the edge surface 415 from about 2 hours to about 4 hours.

[0087] Referring to FIG. 17, the coating 1501 may eventually be removed from the edge surface 415, such that the edge surface 415 may be exposed to the strengthening bath 701. In some embodiments, methods of manufacturing the glass ribbon 104 can comprise exposing the glass ribbon 1401 to the strengthening bath 701 to form the first compressive stress region 401 extending from the first major surface 215 of the glass ribbon 1401, the second compressive stress region 407 extending from the second major surface 216 of the glass ribbon 1401, and the edge compressive stress region 1403 extending from the edge surface 415 of the glass ribbon 1401 extending between the first major surface 215 and the second major surface 216, wherein the first compressive stress of the first compressive stress region 401 and the second compressive stress of the second compressive stress region 407 are each less than the critical buckling stress of the glass ribbon 1401. In some embodiments, the time that the edge surface 415 is exposed to the strengthening bath 701 may be less than the time that the first major surface 215 and the second major surface 216 are exposed to the strengthening bath 701. For example, the first major surface 215 and the second major surface 216 may be exposed to the strengthening bath 701 from about 6 hours to about 8 hours, while the edge surface 415 may be exposed to the strengthening bath 701 from about 2 hours to about 6 hours. Once the coating 1501 has been removed from the edge surface 415, the edge compressive stress region 1403 may be formed at a location extending from the edge surface 415. In some embodiments, the third depth 1405 of the edge compressive stress region 1403 may be less than the first depth 403 of the first compressive stress region 401 and the second depth 409 of the second compressive stress region 407. This difference in depths of the compressive stress regions may be due, in part, to the differing exposure times of the edge surface 415 as compared to the first major surface 215 and the second major surface 216. In some embodiments, due to the reduced depth (e.g., third depth 1405) of the edge compressive stress region 1403 as compared to the first depth 403 and the second depth 409, the likelihood of buckling at the edge 303 of the glass ribbon 1401 may also be reduced.

[0088] As disclosed herein, the glass ribbon 104, 1401 can be thin, for example, by comprising the thickness 301 from 25 micrometers (pm) to about 125 pm, with high compressive stresses, for example, by comprising compressive stress regions from about 600 megapascals (MPa) to about 1500 MPa, while still minimizing the likelihood of buckling at the edge 303 of the glass ribbon 104, 1401. Buckling can be avoided in several ways depending on the number of surfaces of the glass ribbon 104, 1401 that comprise compressive stress regions. For example, when the first major surface 215 and the second major surface 216 comprise compressive stress regions (e.g., the first compressive stress region 401 and the second compressive stress region 407), the edge 303 of the glass ribbon 104 may comprise the unstressed region 413. Forming the unstressed region 413 can be accomplished by masking the edge 303 of the glass ribbon 104 (e.g., with the coating 501), or by oversizing the glass ribbon 104 relative to the desired dimension 903. In some embodiments, the edge 303 of the glass ribbon 104 may comprise the unstressed region 413, wherein the compressive stress of the unstressed region can be nearly zero, which can be less than the critical buckling stress of the glass ribbon 104. Due to the edge 303 comprising a compressive stress that can be less than the critical buckling stress, unwanted buckling of the glass ribbon 104 may be avoided.

[0089] In some embodiments, compressive stress regions may be formed at locations extending from the edge 303 of the glass ribbon 1401, in addition to the first major surface 215 and the second major surface 216. In some embodiments, buckling can be avoided in several ways. For example, in some embodiments, the thickness of the glass ribbon 1401 may be greater than the thickness of the glass ribbon 104, for example, by the thickness of the glass ribbon 1401 being from about 100 pm to about 125 mih. Due to the thickness of the glass ribbon 1401, buckling at the edge 303 may be avoided. In some embodiments, the glass ribbon 1401 can be exposed to the strengthening bath 701 for a shorter time than the glass ribbon 104, which can form compressive stress regions with smaller depths. In addition or in the alternative, the chemistry of the strengthening bath 701 can be altered such that the compressive stresses formed within the glass ribbon 1401 may be lower. Lastly, in some embodiments, the coating 1501 can be applied to the edge surface 415, which may reduce the amount of time that the edge surface 415 can be exposed to the strengthening bath 701, thus reducing the depth of the edge compressive stress region 1403.

[0090] As used herein the terms "the," "a," or "an," mean "one or more," and should not be limited to "only one" unless explicitly indicated to the contrary. Thus, for example, reference to "a component" includes embodiments having two or more such components unless the context clearly indicates otherwise.

[0091] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. When the term“about” is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to. Whether or not a numerical value or end-point of a range in the specification recites“about,” the numerical value or end-point of a range is intended to include two embodiments: one modified by“about,” and one not modified by“about.” 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.

[0092] The terms“substantial,”“substantially,” and variations thereof as used herein are intended to note that a described feature is equal or approximately equal to a value or description. For example, a“substantially planar” surface is intended to denote a surface that is planar or approximately planar. Moreover, as defined above, “substantially similar” is intended to denote that two values are equal or approximately equal. In some embodiments,“substantially similar” may denote values within about 10% of each other, for example within about 5% of each other, or within about 2% of each other.

[0093] As used herein, the terms“comprising” and“including,” and variations thereof shall be construed as synonymous and open-ended, unless otherwise indicated.

[0094] It should be understood that while various embodiments have been described in detail relative to certain illustrative and specific embodiments thereof, the present disclosure should not be considered limited to such, as numerous modifications and combinations of the disclosed features are envisioned without departing from the scope of the following claims.

Claims

What is claimed is:

1. A glass ribbon comprising:

a thickness defined between a first major surface and a second major surface from about 25 pm to about 125 pm;

a first compressive stress region extending from the first major surface to a first depth;

a second compressive stress region extending from the second major surface to a second depth; and

an edge surface extending between the first major surface and the second major surface comprising an unstressed region extending inwardly from the edge surface.

2. The glass ribbon of claim 1, wherein the first compressive stress region is at a location extending from the edge surface.

3. The glass ribbon of claim 2, wherein a first compressive stress of the first compressive stress region is less than a critical buckling stress of the glass ribbon.

4. The glass ribbon of any one of claims 1-3, wherein the second compressive stress region is at a location extending from the edge surface.

5. The glass ribbon of claim 4, wherein a second compressive stress of the second compressive stress region is less than a critical buckling stress of the glass ribbon.

6. The glass ribbon of any one of claims 1-5, wherein one or more of the first major surface or the second major surface are planar.

7. A glass ribbon comprising: a thickness defined between a first major surface and a second major surface from about 25 mih to about 125 mih;

a first compressive stress of the first compressive stress region and a second compressive stress of the second compressive stress region are each less than a critical buckling stress of the glass ribbon.

8. The glass ribbon of claim 7, further comprising an edge surface extending between the first major surface and the second major surface comprising an edge compressive stress region extending inwardly from the edge surface to a third depth.

9. The glass ribbon of claim 8, wherein an edge compressive stress of the edge compressive stress region is less than the critical buckling stress of the glass ribbon.

10. The glass ribbon of any one of claims 7-9, wherein one or more of the first major surface or the second major surface are planar.

11. A method of manufacturing a glass ribbon comprising:

masking an edge surface of the glass ribbon;

exposing the glass ribbon to a strengthening bath to form a first compressive stress region at a first major surface of the glass ribbon and a second compressive stress region at a second major surface of the glass ribbon; and

unmasking the edge surface to expose an unstressed region extending inwardly into the glass ribbon from the edge surface.

12. The method of claim 11, wherein the masking comprises applying a coating to the edge surface.

13. The method of claim 12, wherein the unmasking comprises rinsing the coating from the edge surface.

14. The method of claim 11, wherein the masking comprises oversizing the glass ribbon relative to a desired dimension of the glass ribbon, wherein the edge surface is disposed on a perimeter of the desired dimension of the glass ribbon.

15. The method of claim 14, wherein the unmasking comprises removing an edge portion of the oversized glass ribbon to expose the edge surface on the desired dimension of the glass ribbon.

16. The method of claim 15, wherein the unmasking comprises laser cutting the edge portion from the oversized glass ribbon.

17. The method of any one of claims 11-16, further comprising cleaning the edge surface after the unmasking.

18. A method of manufacturing a glass ribbon comprising:

exposing the glass ribbon to a strengthening bath to form a first compressive stress region at a first major surface of the glass ribbon, a second compressive stress region at a second major surface of the glass ribbon, and an edge compressive stress region extending inwardly from an outer edge surface of the glass ribbon and between the first major surface and the second major surface, wherein a first compressive stress of the first compressive stress region and a second compressive stress of the second compressive stress region are each less than a critical buckling stress of the glass ribbon; and

removing the edge compressive stress region by removing an edge portion of the glass ribbon comprising the outer edge surface.

19. The method of claim 18, wherein the removing the edge compressive stress region comprises laser cutting the edge portion from the glass ribbon.

20. The method of claim 19, further comprising cleaning an edge surface of the glass ribbon exposed after the edge portion is removed.