Method and apparatus of symmetrically chamfering substrate

Abstract

A method of symmetrically chamfering a substrate includes repeating, at least a plurality of times, the steps of chamfering an edge of the substrate using a chamfering wheel, measuring an asymmetric chamfering deviation (y) of the edge of the substrate which is chamfered, and controlling a relative position of the chamfering wheel with respect to the substrate by a value of a function f(y) of the variable y. It is possible to constantly symmetrically chamfer the edge of the substrate via active response to a change in the chamfering environment without a hardware-based operation of the related art.

What is claimed is: 
     
         1 . A method of symmetrically chamfering a substrate, comprising repeating cycles a plurality of times, each cycle comprising:
 chamfering an edge of the substrate using a chamfering wheel;   measuring an asymmetric chamfering deviation (y) of the edge of the substrate which is chamfered; and   controlling a relative position of the chamfering wheel with respect to a position of the substrate by a value of a predetermined function f(y) of the variable y,   wherein different substrates are chamfered in the respective cycles,   wherein in each cycle, the relative position of the chamfering wheel that was previously set is corrected by the value of the function f(y) which is generated in the respective cycle.   
     
     
         2 . The method of  claim 1 , wherein the asymmetric chamfering deviation is a difference between a chamfered width of an upper surface of the substrate and a chamfered width of an undersurface of the substrate. 
     
     
         3 . The method of  claim 2 , wherein
 the relative position of the chamfering wheel is controlled to move upward when the chamfered width of the upper surface of the substrate is greater than the chamfered width of the undersurface of the substrate, and   the relative position of the chamfering wheel is controlled to move downward when the chamfered width of the upper surface of the substrate is smaller than the chamfered width of the undersurface of the substrate.   
     
     
         4 . The method of  claim 1 , wherein the relative position of the chamfering wheel is a relative height of the chamfering wheel with respect to a height of the substrate. 
     
     
         5 . The method of  claim 1 , wherein the value of the function f(y) is obtained by multiplying the asymmetric chamfering deviation (y) by a predetermined control constant. 
     
     
         6 . The method of  claim 1 , wherein different substrates are chamfered in the respective cycles. 
     
     
         7 . The method of  claim 1 , wherein in each cycles,
 a plurality of the asymmetric chamfering deviations are measured at a plurality of points respectively on the edge of the substrate; and   a plurality of the relative positions of the chamfering wheel are controlled when chamfering at the plurality of the points on the edge of the substrate.   
     
     
         8 . The method of  claim 1 , wherein the substrate comprises a glass substrate for a display. 
     
     
         9 . The method of  claim 1 , wherein the chamfering wheel has a concave groove in an outer surface of the chamfering wheel along a circumferential direction thereof. 
     
     
         10 . The method of  claim 1 , wherein measuring the asymmetric chamfering deviation (y) comprises measuring the asymmetric chamfering deviation (y) using a vision camera which detects a chamfered width of an upper surface of the substrate and a chamfered width of an undersurface of the substrate.