Surface flaw modification for strengthening of glass articles

Abstract

Disclosed are controlled chemical etching processes used to modify the geometry of surface flaws in thin glass substrates and glass substrate assemblies formed therefrom, and in particular glass substrates suitable for the manufacture of active matrix displays that are essentially free of alkali metal oxides such as Na 2 O, K 2 O and Li 2 O.

What is claimed is: 
     
         1 . A method for modifying flaws on a glass article comprising:
 contacting the glass article with an aqueous acidic solution for a time from 10 seconds to less than or equal to 10 minutes, whereby glass from the glass article is removed to a depth only from 2.5 μm to less than or equal to 20 μm when the time has elapsed;   rinsing the aqueous acidic solution from the glass article when the time has elapsed.   
     
     
         2 . The method according to  claim 1 , wherein the contacting is conducted for a time from 10 seconds to less than or equal to 5 minutes. 
     
     
         3 . The method according to  claim 1 , wherein the aqueous acidic solution comprises HF and HCl, and wherein a molar concentration of the HF is in a range from about 1.5M to about 4M and a molar concentration of the HCl is in a range from about 4.0M to about 7.0M. 
     
     
         4 . The method according to  claim 1 , wherein the aqueous acidic solution comprises HF and H 2 SO 4 . 
     
     
         5 . The method according to  claim 1 , wherein the glass article comprises a glass substrate and a thickness of the glass substrate is less than or equal to 500 μm before contacting the glass substrate with the aqueous acidic solution. 
     
     
         6 . The method according to  claim 5 , further comprising depositing thin film transistors on the glass substrate. 
     
     
         7 . The method according to  claim 6 , wherein the glass substrate is a first glass substrate, the method further comprising joining the first glass substrate to a second glass substrate to form a glass substrate assembly, there being a gap between the first and second glass substrates. 
     
     
         8 . The method according to  claim 7 , further comprising injecting a liquid crystal material into the gap.