METHOD FOR CUTTING BRITTLE MATERIAL SUBSTRATE

摘要

In the case of cutting a brittle material substrate in two directions intersecting each other using a laser beam, a first scribe line (52a) composed of a perpendicular crack (53a) and a second scribe line (52b) composed of a perpendicular crack (53b) are formed by radiating a laser beam (LB) and blowing a cooling medium from a cooling nozzle (37) so as to suppress the generation of chipping at the intersection area.  The perpendicular crack (53b) is extended by radiating the laser beam (LB) again to the second scribe line (52b), and a substrate (50) is cut at the second scribe line (52b).  Then, the perpendicular crack (53a) is extended by radiating the laser beam (LB) again to the first scribe line (52a), and the substrate (50) is cut at the first scribe line (52a).  At this time, the maximum width of the radiation width of the radiation spot of the laser beam (LB) radiated again to the first scribe line (52a) is 1.0 mm or less.