Working object cutting method

Abstract

A working object cutting method capable of cutting a working object precisely is provided. The working object cutting method comprises irradiating a working object 1 with a laser beam while locating a converging point at the working object, so as to form a reformed region in the working object 1 along a reformed-region forming line 15 set at a predetermined distance inside from an outer edge E of the working object 1 along the outer edge, forming a cutting reformed region in the working object 1 along a cutting-scheduled line 5, and cutting the working object 1 along the cutting-scheduled line 5 from a cutting reformed region acting as a start point. Thus forming the working object 1 with the reformed region along the reformed-region forming line 15 set at a predetermined distance inside from the outer edge E of the working object 1 allows the formed reformed region or fissures extending therefrom to inhibit fissures generated in an outer edge portion 25 of the working object 1 from extending to the inside even if a cutting stress is applied to the working object 1 when cutting the working object 1.

Dependencies are inferred from the claim text.