METHOD FOR PROCESSING BRITTLE SUBSTRATES WITHOUT MICRO-CRACKS

A method for processing a brittle substrate includes first providing a brittle substrate having a substrate surface. Then applying a first laser beam onto the brittle substrate surface to form a pre-cut groove in the brittle substrate, the first laser beam being generated by a solid-state laser device. A second laser beam is then applied onto the brittle substrate surface along the precut groove to heat the brittle substrate, the second laser beam being generated by a gas laser device. Finally, a coolant is applied onto the brittle substrate along the pre-cut groove so as to cause formation of a through crack in the brittle substrate. The first laser beam can be generated by a solid-state laser device, the first laser beam should be of narrow diameter and high energy density, so the first laser beam can form a pre-cut groove rapidly and accurately without generation of micro-cracks, in addition, the pre-cut groove should have a better uniformity and linearity.