METHOD FOR SCORING A SHEET OF BRITTLE MATERIAL

A method of cutting glass that prevents uncontrolled crack propagation when high background stress is present, either in the form of thermal residual stress, external mechanical stress or a combination thereof. The method includes masking an edge of the glass by blocking the beam using highly reflective or absorptive material located near the glass surface, or deposited on the surface in a form of a thin film (or highly reflective paint) to prevent uncontrolled crack initiation and propagation starting from the glass edge. The initiation of the laser scoring is located at a predetermined distance from the glass edge. Yet another aspect of the invention embodies stopping propagation of the vent at the exiting end of the score line.