Patent ID: 8513567
Filing Date: 2013-08-20
Classification: B23K,B28D,H01L

Abstract:
1. A laser processing method including forming a modified region to become a cutting start point within an object to be processed along a cutting line for cutting the object by irradiating the object with laser light while locating a converging point within the object, the method comprising: forming a predetermined modified region formed by irradiation with predetermined laser light whose cross-sectional form at the converging point is such that the maximum length in a direction perpendicular to the cutting line is shorter than the maximum length in a direction parallel to the cutting line, and when forming a plurality of rows of the modified regions with respect to one cutting line, forming at least one of the first and second rows of the modified regions from the laser light incident surface of the object by irradiation with the predetermined laser light, and forming the remaining modified regions by irradiation with the laser light having a cross-sectional form at the converging point such that a maximum length in the direction perpendicular to the cutting line and a maximum length in the direction parallel to the cutting line are substantially equal to each other.