LASER PROCESSING METHOD AND LASER PROCESSING APPARATUS USING SEQUENTIAL MULTI-FOCUSING

摘要

PURPOSE: A laser machining method and apparatus using sequential multi-focusing are provided to prevent the scattering of a laser beam caused by an upper crack row because a lower crack row is formed earlier than the upper crack row inside an work piece. CONSTITUTION: A laser machining method is as follows. A plurality of laser beams(L,L1,L2,L3) are focused on the inside of an work piece(10) to form a plurality of focusing spots(S1,S2,S3). The focusing spots are sequentially arranged at a predetermined depth from a surface(10a) of the work piece. Either the laser beams or the work piece is moved in a first direction and a plurality of crack rows corresponding to the focusing spots are formed inside the work piece.