Glass substrates with strategically imprinted B-side features and methods for manufacturing the same

Patent metadata

Field	Value
Publication number	US-9676649-B2
Application number	US-201113218932-A
Country	US
Kind code	B2
Filing date	Aug 26, 2011
Priority date	Aug 26, 2011
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

Glass substrates and methods for forming glass substrates are disclosed. The glass substrates include a planar A-side surface having a surface roughness Ra 1 of less than 0.5 nm and a planar B-side having a surface roughness Ra 2 wherein the ratio Ra 2 :Ra 1 is greater than or equal to about 1.5. A plurality of texturing features are formed in the B-side surface. The plurality of texturing features have a peak-to-valley height H such that 0.05 μm≦H≦3.75 μm. The texturing features are distributed in the B-side surface such that a center-to-center pitch P between adjacent texturing features is at least 1.5 mm in at least one direction. The plurality of texturing features are formed in the B-side surface while the glass substrate is at a temperature T 1 , wherein 600° C.≦T 1 ≦1200° C. and a viscosity of the glass substrate is from greater than 150,000 Poise and less than 10 13 Poise.

First claim

What is claimed is:

1. A glass substrate comprising:
a planar A-side surface having a surface roughness Ra 1 of less than 0.5 nm;
a planar B-side surface opposed to the A-side surface, the B-side surface comprising:
a surface roughness Ra 2 such that a ratio Ra 2 :Ra 1 is greater than or equal to about 1.5;
a plurality of texturing features formed in the B-side surface such that the texturing features extend from the B-side surface into a thickness S of the glass substrate without extending through the thickness S of the glass substrate, the plurality of texturing features having a peak-to-valley height H such that 0.05 μm≦H≦3.75 μm; and
a center-to-center pitch P between adjacent texturing features is at least 1.5 mm in at least one direction.

2. The glass substrate of claim 1 , wherein H≦0.04*S.

3. The glass substrate of claim 1 , wherein the center-to-center pitch P between adjacent texturing features is less than or equal to 25 mm.

4. The glass substrate of claim 1 , wherein the B-side surface of the glass substrate has a planar area A and a contact surface area C, wherein C≦0.5*A.

5. A method for forming a glass substrate, the method comprising:
melting glass batch materials to form molten glass;
forming the molten glass into a glass substrate having a planar A-side surface and a planar B-side surface opposed to the A-side surface, wherein the glass substrate is formed without mechanically contacting at least the A-side surface prior to the glass substrate solidifying to a viscosity greater than 10 13 Poise, wherein the planar A-side surface has a surface roughness Ra 1 of less than 0.5 nm after solidification;
drawing the glass substrate in a downward direction;
forming a plurality of texturing features into the B-side surface of the glass substrate while the glass substrate is at a temperature T 1 , wherein:
600° C.≦T 1 ≦1200° C.;
the texturing features extend from the B-side surface into a thickness of the glass substrate without extending through the thickness of the glass substrate;
the plurality of texturing features have a peak-to-valley height H such that 0.05 μm≦H≦3.75 μm;
a center-to-center pitch P between adjacent texturing features is at least 1.5 mm in at least one direction; and
the B-side surface has a surface roughness Ra 2 such that a ratio Ra 2 :Ra 1 is greater than or equal to about 1.5.

6. The method of claim 5 , wherein the plurality of texturing features have a first size D 1 while the glass substrate is at the temperature T 1 and a second size D 2 when the glass substrate is cooled to room temperature, wherein D 1 >D 2 .

7. The method of claim 5 , wherein the texturing features are formed by selectively drawing heat from the surface of the glass substrate as the glass substrate is drawn in the downward direction.

8. The method of claim 5 , wherein the plurality of texturing features are formed in the B-side surface of the glass substrate by directing at least one stream of compressed gas onto the B-side surface of the glass substrate as the glass substrate is drawn in the downward direction.

9. The method of claim 5 , wherein the plurality of texturing features are formed in the B-side surface of the glass substrate by contacting the B-side surface of the glass substrate with a texturing roller, wherein at least a portion of a contact surface of the texturing roller comprises a plurality of patterning features corresponding to the texturing features imprinted on the B-side surface.

10. The method of claim 9 , wherein a temperature T 2 of the texturing roller is actively controlled such that T 2 <T 1 .

11. The method of claim 9 , wherein the texturing roller is stationary and the B-side surface of the glass substrate is tangential to the contact surface of the texturing roller when the B-side surface of the glass substrate contacts the contact surface of the texturing roller.

12. The method of claim 9 , wherein the texturing roller is stationary and the B-side surface of the glass substrate is directed over the contact surface of the texturing roller such that the B-side surface has a contact angle with the contact surface of up to about 90°.

13. The method of claim 9 , wherein the texturing roller is actively rotated as the glass substrate is drawn in the downward direction with pulling rollers.

14. The method of claim 5 , wherein:
the glass substrate is formed by flowing the molten glass over only one side of an isopipe; and
the plurality of texturing features are formed by directing the glass substrate onto a landing extending from a root of the isopipe as the glass substrate is drawn in the downward direction, wherein the molten glass contacting the landing forms the texturing features in B-side surface of the glass substrate.

15. The method of claim 14 , wherein at least a portion of a contact surface of the landing comprises a plurality of patterning features corresponding to the texturing features imprinted into the B-side surface.

16. The method of claim 5 , wherein:
the glass substrate is formed by flowing the molten glass over a first side of an isopipe and a second side of the isopipe such that the molten glass rejoins at a root of the isopipe, wherein the second side of the isopipe comprises a plurality of patterning features corresponding to the texturing features imprinted into the B-side surface of the glass substrate; and
the plurality of texturing features are formed in the B-side surface of the glass substrate as the molten glass flows over the second side of the isopipe and the patterning features disrupt the flow of molten glass over the second side of the isopipe.

17. The method of claim 5 , wherein:
the plurality of texturing features are formed in the B-side surface of the glass substrate by directing a beam of at least one laser source onto the B-side surface of the glass substrate such that the beam of the at least one laser source imprints the plurality of texturing features into the B-side surface of the glass substrate without ablating glass from the glass substrate as the glass substrate is drawn in the downward direction.

Assignees

• Dobbins Michael Sean
• Lim James Robert
• Lu Hung Cheng (Henry)
• Walczak Wanda Janina
• Wang Liming
• Yongsunthon Ruchirej
• Corning Inc

Inventors

• Dobbins Michael Sean
• Lim James Robert
• Lu Hung Cheng (Henry)
• Walczak Wanda Janina
• Wang Liming
• Yongsunthon Ruchirej

Classifications

• H01L29/78603

  Electricity · mapped topic

• C03B17/065 Primary

  Forming profiled, patterned or corrugated sheets · CPC title

• Y02P40/57

  Improving the yield, e-g- reduction of reject rates · CPC title

• Y10T428/24355

  Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.] · CPC title

• C03C2204/08

  Glass having a rough surface · CPC title