CUTTING METHOD FOR STRENGTHENED GLASS PLATE

摘要

A cutting method for a strengthened glass plate, having a step that irradiates laser light (20) on the surface (12) of the strengthened glass plate (10) and moves an irradiation area (22) for the laser light (20) on top of the surface (12) of the strengthened glass plate (10). The laser light has a wavelength of 800-1,100 nm and 70.00%-99.8% of the laser light (20) incident on the surface (12) of the strengthened glass plate (10) is transmitted therethrough. In addition, by heating the intermediate layer (17) in the irradiation area (22) for the laser light (20) to an annealing point temperature max., while moving the irradiation area (22) at 1.0 mm/sec min, a crack penetrating the strengthened glass plate (10) in the plate thickness direction behind the irradiation area (22) is caused to follow the irradiation area (22) and cuts the strengthened glass plate (10).