Laser processing method of a workpiece by forming division originating points inthere, dividing method for a workpiece, and laser processing apparatus

摘要

Provided are a processing method for forming division originating points (RE1,RE2,RE3,RE4) in a workpiece and a laser processing apparatus performing the method, which are capable of reducing light absorption in a processing trail, increasing light extraction efficiency from sapphire, and performing high speed processing. A pulsed laser beam is irradiated to a workpiece so that irradiation regions (RE1,RE2,RE3,RE4) for each of unit pulsed beams of the pulsed laser beam of ultra-short pulse are formed discretely in the workpiece, and cleavage or parting of the workpiece is sequentially generated between the irradiation regions (RE1,RE2,RE3,RE4) by a shock or a stress when each of unit pulsed beam is irradiated at an irradiation point (RE1,RE2,RE3,RE4), to thereby form originating points (RE1,RE2,RE3,RE4) for division in the workpiece.