| 摘要 |
<p>In the present invention, a first scribe line (52a) comprising a perpendicular crack (53a) and a second scribe line (52b) comprising a perpendicular crack (53b) are formed by laser beam (LB) irradiation and the spray of a cooling medium from a cooling nozzle (37). The second scribe line (52b) is again irradiated with the laser beam (LB) to extend the perpendicular crack (53b), and a substrate (50) is fractured at the second scribe line (52b). Next, the intersection point region between a fracture line (54) and the first scribe line (52a) is covered with a glass plate (61) and water droplets (62). Then, the first scribe line (52a), except for the intersection region, is again irradiated with the laser beam (LB) to extend the perpendicular crack (53a), and the substrate (50) is fractured at the first scribe line (52a). This suppresses the occurrence of splintering at the point of intersection in a case where a brittle material substrate is fractured in two intersecting directions using a laser.</p> |
