Laser cutting and removal of contoured shapes from transparent substrates

Abstract

A method for cutting, separating and removing interior contoured shapes in thin substrates, particularly glass substrates. The method involves the utilization of an ultra-short pulse laser to form defect lines in the substrate that may be followed by use of a second laser beam to promote isolation of the part defined by the interior contour.

What is claimed is: 
     
         1 . A glass article comprising:
 a first major surface;   a second major surface opposite the first major surface;   a circular inner perimeter;   a circular outer perimeter concentric with the inner perimeter, the inner perimeter and the outer perimeter defining an annulus therebetween, a thickness extending between first and second major surfaces equal to or less than about 1 millimeter, a first unground and unpolished edge surface between the first and second major surfaces and extending around the inner perimeter and a second unground and unpolished edge surface between the first and second major surfaces and extending around the outer perimeter; and   wherein an R a  surface roughness of at least one of the first or second edge surfaces is equal to or less than about 0.5 micrometers.   
     
     
         2 . The glass article according to  claim 1 , wherein at least one of the first or second edge surfaces comprises a plurality of defect lines extending orthogonally between the first and second major surfaces, and wherein a diameter of each defect line is less than or equal to about 5 micrometers. 
     
     
         3 . The glass article according to  claim 1 , wherein a depth of subsurface damage along either one of the first or second edge surfaces is equal to or less than about 75 micrometers. 
     
     
         4 . The glass article according to  claim 3 , wherein the depth of subsurface damage is equal to or less than about 25 micrometers. 
     
     
         5 . The glass article according to  claim 1 , wherein a warp of the glass article is equal to or less than about 50 micrometers. 
     
     
         6 . The glass article according to  claim 5 , wherein the warp is equal to or less than about 15 micrometers. 
     
     
         7 . The glass article according to  claim 1 , wherein an anneal point of the glass article is equal to or greater than about 700° C. 
     
     
         8 . The glass article according to  claim 7 , wherein the anneal point of the glass article is equal to or greater than about 800° C. 
     
     
         9 . The glass article according to  claim 1 , wherein a compaction of the glass article after exposure to a temperature of 600° C. for a period of 30 minutes, upon cooling to a temperature of 23° C., is equal to or less than about 35 ppm. 
     
     
         10 . The glass article according to  claim 1 , wherein the compaction is equal to or less than about 20 ppm. 
     
     
         11 . The glass article according to  claim 1 , wherein the glass article comprises equal to or less than 5 MPa internal residual stress. 
     
     
         12 . The glass article according to  claim 1 , wherein the glass article is a chemically strengthened glass. 
     
     
         13 . The glass article according to  claim 1 , wherein an average roughness R a  of either one of the first or second major surfaces is less than about 1 nanometer. 
     
     
         14 . The glass article according to  claim 13 , wherein the average roughness R a  of either one of the first or second major surfaces is less than about 0.5 nanometers. 
     
     
         15 . The glass article according to  claim 1 , wherein the glass article comprises equal to or less than about 0.5 wt. %, SnO 2 . 
     
     
         16 . The glass article according to  claim 1 , wherein the glass article comprises equal to or less than about 0.15 wt. % SnO 2 . 
     
     
         17 . The glass article according to  claim 1 , wherein a distance between adjacent defect lines of the plurality of defect lines is equal to or less than about 7 micrometers. 
     
     
         18 . The glass article according to  claim 1 , wherein the glass article comprises less than or equal to 0.1% of an alkali metal oxide. 
     
     
         19 . The glass article according to  claim 1 , wherein the first and second major surfaces are unground and unpolished. 
     
     
         20 . The glass article according to  claim 1 , wherein the first and second major surfaces are free of any coating. 
     
     
         21 . The glass article according to  claim 1 , wherein a diameter of the circular outer perimeter is within +/−15 micrometers of a predetermined nominal circular outer diameter. 
     
     
         22 . The glass article according to  claim 21 , wherein the diameter of the circular outer perimeter is within +/−10 micrometers of the predetermined nominal circular outer diameter. 
     
     
         23 . The glass article according to  claim 1 , wherein a diameter of the circular inner perimeter is within +/−25 micrometers of a predetermined nominal circular inner diameter. 
     
     
         24 . The glass article according to  claim 23 , wherein the diameter of the circular inner perimeter is within +/−10 micrometers of the predetermined nominal circular inner diameter. 
     
     
         25 . The glass article according to  claim 1 , wherein a center of the inner circular perimeter and a center of the outer circular perimeter are displaced from each other by no more than about 10 micrometers. 
     
     
         26 . The glass article according to  claim 25 , wherein the center of the inner circular perimeter and the center of the outer circular perimeter are displaced from each other by no more than about 5 micrometers.