Method for flattening glass substrate

Abstract

A method for flattening a glass substrate includes the steps of preparing plural kinds of etching liquids different from one another in an etching rate, preparing the glass substrate, and etching the glass substrate at least one time with each of the etching liquids and executing the etching a plurality of times in total. When the etchings are executed the plurality of times, an etching rate of the glass substrate with one etching liquid used for one etching of plural etchings is slower than that of the glass substrate with the another etching liquid used for another etching executed after the one etching process of the plural etching processes.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.

FIG. 1 is a flowchart showing a method for flattening a glass substrate according to a first embodiment of the present invention;

FIG. 2A is a diagram showing concave portions of a surface of the glass substrate;

FIG. 2B is a diagram showing dimples of the surface of the glass substrate;

FIG. 3 is a diagram showing flatness of the surface of the glass substrate obtained by the method for flattening the glass substrate according to the first embodiment of the present invention;

FIG. 4 is a diagram showing flatness of a surface of a glass substrate for comparison;

FIG. 5 is a diagram showing flatness of a surface of a glass substrate obtained by a method for flattening the glass substrate according to a second embodiment of the present invention;

FIG. 6 is a flowchart showing a method for flattening a glass substrate according to a third embodiment of the present invention;

FIG. 7A is a diagram showing a state in which an inactive liquid sticks to an entire surface of the glass substrate including surface concave portions;

FIG. 7B is a diagram showing a state in which an inactive liquid sticks to the surface concave portions alone of the glass substrate; and

FIG. 7C is a diagram showing a state in which growth of the surface concave portions of the glass substrate is suppressed.

Claims

1. A method for flattening a glass substrate, comprising: preparing plural kinds of etching liquids different from one another in an etching rate;preparing the glass substrate; andexecuting a plurality of etching processes of the glass substrate at least one time with each of the etching liquids and executing the etching processes a plurality of times in total, wherein:when the etching processes are executed the plurality of times, an etching rate of the glass substrate with one etching liquid used for one etching process of the plural etching processes is slower than that of the glass substrate with another etching liquid used for another etching process executed after the one etching process of the plural etching processes.

2. The method according to claim 1, wherein: the execution of the etching processes the plurality of times includes execution of a first etching process and a second etching process,the execution of the first etching process uses a first etching liquid whose etching rate is a predetermined value for the glass substrate, andthe execution of the second etching process uses a second etching liquid whose etching rate is faster than the predetermined value for the glass substrate.

3. The method according to claim 2, wherein: the etching rate of the first etching liquid for the glass substrate is not less than 0.01 μm/minute and less than 5 μm/minute, andthe etching rate of the second etching liquid for the glass substrate is not less than 5 μm/minute and not more than 15 μm/minute.

4. The method according to claim 2, wherein the first etching liquid contains one or more kinds of fluorine compounds.

5. The method according to claim 2, wherein the glass substrate is dipped in a liquid inactive to the first and second etching liquids before the etching process is executed the plurality of times.

6. The method according to claim 5, wherein the second etching liquid contains an inorganic oxo acid additive.

7. The method according to claim 1, wherein the first etching liquid contains one or more kinds of fluorine compounds.

8. The method according to claim 1, wherein the glass substrate is dipped in a liquid inactive to the first etching liquid and another etching liquid before the etching processes are executed the plurality of times.

9. The method according to claim 8, wherein the another etching liquid contains an inorganic oxo acid additive.

10. The method according to claim 1, wherein at least one etching process of the plural etching processes includes formation of a protective layer in one surface of the glass substrate.

11. A method for flattening a glass substrate, comprising: preparing plural kinds of etching liquids different from one another in an etching rate;preparing an assembly including two glass substrates; andexecuting a plurality of etching processes of the assembly at least one time with each of the etching liquids and executing the etching processes a plurality of times in total, wherein:when the etching processes are executed the plurality of times, an etching rate of the glass substrate with one etching liquid used for one etching process of the plural etching processes is slower than that of the glass substrate with another etching liquid used for another etching process executed after the one etching process of the plural etching processes, andthe preparation of the assembly includes:forming a plurality of sealing materials on one of the two glass substrates, and forming an outer peripheral sealing material having a separated opening in at least one place in an outer periphery of the one glass substrate,laminating the two glass substrates via the plurality of sealing materials and the outer peripheral sealing material, andsealing of the opening with a sealant.

12. The method according to claim 11, wherein: the execution of the etching processes the plurality of times includes execution of a first etching process and a second etching process,the execution of the first etching process uses a first etching liquid whose etching rate is a predetermined value for the glass substrate, andthe execution of the second etching process uses a second etching liquid whose etching rate is faster than the predetermined value for the glass substrate.

13. The method according to claim 12, wherein the first etching liquid contains one or more kinds of fluorine compounds.

14. The method according to claim 12, wherein the glass substrate is dipped in a liquid inactive to the first and second etching liquids before the etching is executed the plurality of times.

15. The method according to claim 14, wherein the second etching liquid contains an inorganic oxo acid additive.

16. The method according to claim 11, wherein each of the glass substrates has an area which permits formation of a plurality of completed liquid crystal display panels.

17. The method according to claim 11, wherein the execution of etching processes the plurality of times includes an etching process of one surface of the assembly to flatten the surface.

18. The method according to claim 17, wherein when the etching processes are executed the plurality of times, prior to the etching process of one surface of the assembly to flatten the same, a protective layer is formed in the other surface of the assembly.

19. The method according to claim 17, wherein when the etching processes are executed the plurality of times, simultaneously with the etching process of one surface of the assembly to flatten the same, the other surface of the assembly is etched to be flattened.