Glass substrate and a manufacturing method thereof

Abstract

A method for manufacturing a glass substrate by fusion process comprising the following steps; flowing fused glass into a fusion pipe, and gradually cooling and solidifying the fused glass by flowing downward from the fusion pipe, wherein forming an asperity on a surface of the glass substrate by fastening and pressing the glass toward a direction of thickness of the glass with a pair of transfer rollers during the glass is flowing down from the fusion pipe.

1 . A glass substrate comprising a surface having an asperity of a height in the range from 10 nm to 20 nm and of a period in the range from 0.1 mm to 1 mm.  
     
     
         2 . The glass substrate of  claim 1 , wherein the height is in the range from 15 nm to 20 nm and the period is in the range from 0.1 mm to 0.6 mm.  
     
     
         3 . The glass substrate of  claim 1 , wherein the asperity exists only on one side of said substrate.  
     
     
         4 . The glass substrate of  claim 1 , wherein the glass substrate has a length and a width each 1000 mm or more, respectively, and a thickness of 1.2 mm or less.  
     
     
         5 . The glass substrate of  claim 1 , which comprises non-alkaline glass.  
     
     
         6 . A method for manufacturing a glass substrate by fusion process, the method comprising the steps of; 
 flowing fused glass into a fusion pipe, and    gradually cooling and solidifying the fused glass by flowing downward from the fusion pipe,    wherein an asperity is formed on a surface of the glass substrate by depositing particles on a surface of the fused glass.    
     
     
         7 . The method for manufacturing a glass substrate of  claim 6 , wherein the particles comprise the same glass material as the fused glass.  
     
     
         8 . The method for manufacturing a glass substrate of  claim 6 , wherein the glass particles are deposited on a surface of the fused glass at a flow passage of the fused glass leading to the fusion pipe.  
     
     
         9 . The method for manufacturing a glass substrate of  claim 6 , wherein the glass particles are discharged from above the fusion pipe, and are deposited on a surface of the fused glass in the fusion pipe.  
     
     
         10 . The method for manufacturing a glass substrate of  claim 6 , wherein the glass particles are discharged from one side or both sides of the fusion pipe and are deposited on a surface of the fused glass.  
     
     
         11 . The method for manufacturing a glass substrate of  claim 6 , wherein a diameter of the glass particles is in the range from 15 nm to 40 nm.  
     
     
         12 . The method for manufacturing a glass substrate of  claim 6 , wherein the asperity has a height in the range from 10 nm to 20 nm and a period in the range from 0.1 mm to 1 mm.  
     
     
         13 . The method for manufacturing a glass substrate of  claim 6 , wherein the asperity has a height in the range from 15 nm to 20 nm and a period in the range from 0.1 mm to 0.6 mm.  
     
     
         14 . The method for manufacturing a glass substrate of  claim 6 , wherein the glass substrate has a length and a width, each 1000 mm or more, respectively, and has a thickness of 1.2 mm or less.  
     
     
         15 . The method for manufacturing a glass substrate of  claim 6 , wherein the glass substrate comprises non-alkaline glass.  
     
     
         16 . A method for manufacturing a glass substrate by fusion process, the method comprising the steps of; 
 flowing fused glass into a fusion pipe, and    gradually cooling and solidifying the fused glass by flowing downward from the fusion pipe,    wherein an asperity is formed on a surface of the glass substrate by colliding particles against the glass flowing down from the fusion pipe from a side direction.    
     
     
         17 . The method for manufacturing a glass substrate of  claim 16 , wherein the particles comprise at least one of glass, metal and ceramics.  
     
     
         18 . The method for manufacturing a glass substrate of  claim 16 , wherein the asperity on a surface of said glass substrate is formed by colliding particles against only one side of the glass flowing down.  
     
     
         19 . The method for manufacturing a glass substrate of  claim 16 , wherein the asperity has a height in the range from 10 nm to 20 nm and a period in the range from 0.1 mm to 1 mm.  
     
     
         20 . The method for manufacturing a glass substrate of  claim 16 , wherein the asperity has a height in the range from 15 nm to 20 nm and a period in the range from 0.1 mm to 1 mm.  
     
     
         21 . The method for manufacturing a glass substrate of  claim 16 , wherein the glass substrate has a length and a width, each 1000 mm or more, respectively, and a thickness of 1.2 mm or less.  
     
     
         22 . The method for manufacturing a glass substrate of  claim 16 , wherein the glass substrate comprises non-alkaline glass.  
     
     
         23 . A method for manufacturing a glass substrate by fusion process, the method comprising the steps of; 
 flowing fused glass into a fusion pipe, and    gradually cooling and solidifying the fused glass by flowing downward from the fusion pipe,    wherein an asperity is formed on a surface of the glass substrate by pinching and pressing the glass toward a direction of thickness of the glass with a pair of transfer rollers during the glass is flowing down from the fusion pipe.    
     
     
         24 . The method for manufacturing a glass substrate of  claim 23 , wherein a surface of at least one of the pair of transfer rollers has an asperity of a height in the range from 10 nm to 40 nm and of a period in the range from 0.1 mm to 1.2 mm.  
     
     
         25 . The method for manufacturing a glass substrate of  claim 23 , wherein the asperity has a height in the range from 10 nm to 20 nm and a period in the range from 0.1 mm to 1 mm.  
     
     
         26 . The method for manufacturing a glass substrate of  claim 23 , wherein the asperity has a height in the range from 15 nm to 20 nm and a period in the range from 0.1 mm to 0.6 mm.  
     
     
         27 . The method for manufacturing a glass substrate of  claim 23 , wherein the glass substrate has a length and a width, each 1000 mm or more, respectively, and a thickness of 1.2 mm or less.  
     
     
         28 . The method for manufacturing a glass substrate of  claim 23 , wherein the glass substrate comprises non-alkaline glass.  
     
     
         29 . A method for manufacturing a glass substrate by fusion process, the method comprising the steps of, 
 flowing fused glass into a fusion pipe,    overflowing the fused glass toward two directions of the fusion pipe and flowing the fused glass along two side surfaces of the fusion pipe,    joining the fused glass at a blade portion which is a bottom end of the fusion pipe, and    gradually cooling and solidifying the fused glass by flowing downward from the blade portion,    wherein an asperity is formed on a surface of the glass substrate by periodically changing a temperature difference between the two side surfaces of the fusion pipe.    
     
     
         30 . The method for manufacturing a glass substrate of  claim 29 , wherein the asperity has a height in the range from 10 nm 20 nm and a period in the range from 0.1 to 1 mm.  
     
     
         31 . The method for manufacturing a glass substrate of  claim 29 , wherein the asperity has a height in the range from 15 nm to 20 nm and a period in the range from 0.1 mm to 0.6 mm.  
     
     
         32 . The method for manufacturing a glass substrate of  claim 29 , wherein the glass substrate has a length and a width, each 1000 mm or more, respectively, and a thickness of 1.2 mm or less.  
     
     
         33 . The method for manufacturing a glass substrate of  claim 29 , wherein the glass substrate comprises non-alkaline glass.