Methods for laser processing transparent workpieces using pulsed laser beam focal lines and vapor etching

Abstract

A method for processing a transparent workpiece includes directing a pulsed laser beam into the transparent workpiece such that a portion of the pulsed laser beam directed into the transparent workpiece generates an induced absorption within the transparent workpiece, thereby forming a damage line within the transparent workpiece, and the portion of the pulsed laser beam directed into the transparent workpiece includes a wavelength λ, a spot size wo, and a Rayleigh range ZR that is greater thanFD⁢π⁢w0,2λ,where FD is a dimensionless divergence factor comprising a value of 10 or greater. Further, the method for processing the transparent workpiece includes etching the transparent workpiece with an etching vapor to remove at least a portion of the transparent workpiece along the damage line, thereby forming an aperture extending through the at least a portion of the thickness of the transparent workpiece.

What is claimed is: 
     
         1 . A glass article comprising:
 a glass substrate having a first major surface and a second major surface opposite the first major surface and separated from the first major surface by a thickness; and   a plurality of apertures extending through the glass substrate from the first major surface to the second major surface, wherein:
 each of the plurality of apertures has an average diameter of greater than or equal to 5 μm and less than or equal to 20 μm; and 
 an aspect ratio of the average thickness of the glass substrate to the average diameter of the plurality of apertures is greater than or equal to 20:1. 
   
     
     
         2 . The glass article according to  claim 1 , wherein the aspect ratio is greater than or equal to 30:1. 
     
     
         3 . The glass article according to  claim 1 , wherein the aspect ratio is greater than or equal to 40:1. 
     
     
         4 . The glass article according to  claim 1 , wherein a difference between a diameter at the first major surface of each of the plurality of apertures and a diameter at a distance of half of the average thickness of the glass substrate from the first major surface of each of the plurality of apertures is less than or equal to 30%. 
     
     
         5 . The glass article according to  claim 1 , wherein the glass article comprises high purity fused silica. 
     
     
         6 . The glass article according to  claim 1 , wherein the glass article comprises borosilicate glass. 
     
     
         7 . The glass article according to  claim 1 , wherein the glass article comprises a glass having a silica content of greater than or equal to 95 mol %.