Patent ID: 6787732
Filing Date: 2004-09-07
Classification: B23K,B28D,C03B,Y02P

Abstract:
A method of separating a sheet of a brittle material into portions by means of laser-scribing, comprising steps of:(a) providing a sheet of a brittle material having first and second opposing major surfaces separated by a thickness t; (b) providing a source of laser energy adjacent one of said first and second surfaces, said laser energy source adapted for supplying a focussed beam of laser energy converging to a focal spot in a plane parallel to said one surface; (c) irradiating said sheet of brittle material with said focussed beam of laser energy from said source, said plane of said focal spot of said laser beam initially being positioned within said sheet just below said first surface thereof; and (d) continuing said irradiating while simultaneously: (1) providing relative movement between said focal spot of said laser beam and said sheet to move said focal spot at a pre-selected rate along a pre-selected path extending over said first surface, and (2) moving the depth of said plane of said focal spot at a pre-selected rate through a major portion of said thickness t of said sheet to form a micro-crack zone extending along said pre-selected path from just below said first surface to a shallow depth just below said second surface.