Corning Incorporated
Methods for laser processing a substrate stack having one or more transparent workpieces and a black matrix layer

Abstract:

A method for laser processing a substrate stack includes forming a defect in a transparent workpiece of the substrate stack having a black matrix layer. Forming the defect includes directing a portion of a pulsed laser beam into the transparent workpiece. The pulsed laser beam includes a wavelength .lamda., a spot size w.sub.o, and a Rayleigh range Z.sub.R that is greater than .times..pi..times..times..lamda. ##EQU00001## where F.sub.D is a dimensionless divergence factor comprising a value of 10 or greater. The pulsed laser beam directed into the transparent workpiece of the substrate stack forms a pulsed laser beam focal line disposed within the transparent workpiece, where a center of the pulsed laser beam focal line is offset from an edge of the black matrix layer by a distance that is about 20% or less of a total thickness of the substrate stack and generates an induced absorption within the transparent workpiece.