| 摘要 |
PROBLEM TO BE SOLVED: To avoid unintended breaking of a first brittle substrate and meanwhile, to provide a line along which the first brittle substrate is broken even in a portion covered with a second brittle substrate.SOLUTION: A method for breaking a brittle substrate is provided, in which: a trench line TL is formed on a first brittle substrate 11 by sliding a blade edge on a first principal surface SF1 of the first brittle substrate 11, where the trench line TL is formed so that the substrate is in a crackless state; the first brittle substrate 11 and a second brittle substrate 12 are adhered to each other so that the trench line TL formed on the first brittle substrate 11 is at least covered partially by the second brittle substrate 12; and thereafter, a crack is extended from the trench line TL along the thickness direction of the first brittle substrate 11 to form a crack line CL, where continuous connection in a direction intersecting with the trench line TL in the first brittle substrate 11 is cut off by the crack line CL at a portion immediately below the trench line TL. |
