Method for forming vertical crack in brittle material substrate and method for cutting brittle material substrate

摘要

Provided is a method for forming a vertical crack without cullet in a brittle material substrate. The method for forming a vertical crack in a brittle material substrate comprises: a trench line forming process of forming a trench line which is a concave part of a line shape on one surface; and a pressure mark forming process of forming a pressure mark by locally pressing around the trench line with a certain pressing object. In the process of forming the trench line, the trench line is formed to maintain a status where no crack is formed right under the trench line. In the process of forming the pressure mark, a vertical crack is extended along the thickness of a brittle material substrate from the trench line according to the pressure mark formed.