Tempered glass substrate and method of producing the same

• US 9,054,250 B2
• Filed: 02/04/2009
• Issued: 06/09/2015
• Est. Priority Date: 08/03/2007
• Status: Active Grant

• Current Assignee: Nippon Electric Glass Company Limited
• Original Assignee: Nippon Electric Glass Company Limited
• Inventors: Murata, Takashi
• Primary Examiner(s): Sample, David
• Assistant Examiner(s): COLGAN, LAUREN ROBINSON
• Application Number:
  US12/320,786
• Publication Number:
  US 20090197088A1
• Time in Patent Office: 2,316 Days
• Field of Search: 428/409, 428/410, 501/55, 501/68, 501/69, 501/70, 65/301.4
• US Class Current: 1/1
• CPC Class Codes: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 takes precedence
• CPC Class Codes: C03C 23/007 by thermal treatment
• CPC Class Codes: C03C 3/083 containing aluminium oxide or an iron compound
• CPC Class Codes: C03C 3/087 containing calcium oxide, e.g. common sheet or container glass
• CPC Class Codes: C03C 3/091 containing aluminium
• CPC Class Codes: C03C 3/093 containing zinc or zirconium
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: H01L 31/0392 including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate textured substrates H01L31/02366
• CPC Class Codes: H01L 31/048 Encapsulation of modules
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/31 Surface property or characteristic of web, sheet or block
• CPC Class Codes: Y10T 428/315 Surface modified glass [e.g., tempered, strengthened, etc.]

Abstract

A tempered glass substrate of the present invention is a tempered glass substrate, which has a compression stress layer on a surface thereof, and has a glass composition comprising, in terms of mass %, 40 to 71% of SiO₂, 3 to 21% of Al₂O₃, 0 to 3.5% of Li₂O, 7 to 20% of Na₂O, and 0 to 15% of K₂O.

Claims

1. A tempered glass substrate, which has a compression stress layer on a surface thereof, and has a glass composition comprising, in terms of mass %, 58.4 to 70% of SiO₂, 12 to 23% of Al₂O₃, 0 to 1% of Li₂O, 7 to 20% of Na₂O, 0 to 2% of K₂O, 0 to 4% of MgO+CaO+SrO+BaO, 0.01 to 3% of SnO₂, and less than 0.1% of As₂O₃, wherein the glass composition comprises a mass ratio of K₂O/Na₂O of 0 to 0.2, and wherein the compression stress layer has a depth of 37 μ

m or less.

2. The tempered glass substrate according to claim 1, which is chemically tempered.

3. The tempered glass substrate according to claim 1, wherein a compression stress of the surface is 300 MPa or more, a depth of the compression stress layer is 10 μ

m to 37 μ

m, and an internal tensile stress in the glass substrate is 200 MPa or less.

4. The tempered glass substrate according to claim 1, wherein the surface is an unpolished surface.

5. The tempered glass substrate according to claim 4, wherein the unpolished surface has an average surface roughness Ra of 10 Å

or less.

6. The tempered glass substrate according to claim 1, wherein the tempered glass substrate is composed of a glass having a liquidus temperature of 1200°

C. or lower.

7. The tempered glass substrate according to claim 1, wherein the tempered glass substrate is composed of a glass having a liquidus viscosity of 10^5.0 dPa·

s or more.

8. The tempered glass substrate according to claim 1, which is used as a cover glass of a display.

9. The tempered glass substrate according to claim 1, which is formed into a plate shape by an overflow down draw method.

10. The tempered glass substrate according to claim 1, wherein a compression stress of the surface is 300 MPa or more, and the depth of the compression stress layer is 10 μ

m to 37 μ

m.

11. The tempered glass substrate according to claim 1, wherein an internal tensile stress in the glass substrate is 150 MPa or less.

12. The tempered glass substrate according to claim 1, wherein the glass composition further comprises 0.001 to 10% of ZrO₂.

13. The tempered glass substrate according to claim 1, wherein the tempered glass substrate has a cut end surface which is cut after forming the compression stress layer on the surface by an ion exchange.

14. The tempered glass substrate according to claim 1, wherein the tempered glass substrate has a chamfered cut end surface.

15. The tempered glass substrate according to claim 1, wherein the surface is an unpolished surface, and wherein the tempered glass substrate has a chamfered cut end surface.

16. The tempered glass substrate according to claim 1, wherein the tempered glass substrate has a cut end surface which is cut after forming the compression stress layer on the surface, and wherein the cut end surface is chamfered.

17. The tempered glass substrate according to claim 1, wherein the surface is an unpolished surface, and wherein the tempered glass substrate has a cut end surface which is cut after forming the compression stress layer on the surface.

18. The tempered glass substrate according to claim 1, wherein the glass composition further comprises 0 to 1% of CaO.

19. The tempered glass substrate according to claim 1, wherein a compression stress of the compression stress layer is 800 MPa or more.

20. The tempered glass substrate according to claim 1, wherein the glass composition further comprises 0 to 1% of CaO, and the tempered glass substrate is composed of a glass having a liquidus viscosity of 10^5.0 dPa·

s or more.

21. The tempered glass substrate according to claim 1, wherein the glass composition further comprises 4% or less of TiO₂, and the tempered glass substrate is composed of a glass having a liquidus viscosity of 10^5.0 dPa·

s or more.

22. The tempered glass substrate according to claim 1, wherein a mass fraction of (MgO+CaO+SrO+BaO)/(Li₂O+Na₂O+K₂O) is 0.5 or less.