METHOD OF WORKING WORKPIECE OF HIGHLY BRITTLE NONMETALLIC MATERIAL AND APPARATUS THEREFOR

摘要

Scribe crack resulting from growth of scribe line cannot be formed to a desirable depth through sequentially forming of a heating region, cooling region and reheating region. Accordingly, there is provided a method comprising, sequentially performed, the first step of irradiating heating region (3) with a heating energy with its intensity controlled and conducting scanning along predetermined working line (2b); the second step of irradiating cooling region (4a) positioned posteriorly in the direction of relative movement of the heating region (3) of the first step with cold energy and conducting scanning along the predetermined working line (2b) to thereby form a scribe line; and the third step of irradiating reheating region (5a) positioned posteriorly in the direction of relative movement of the cooling region (4a) of the second step with a heating energy with its intensity controlled and conducting scanning along the predetermined working line (2b) to thereby form a scribe line, wherein in order to form scribe crack (5b) resulting from growth of the scribe line to a desirable depth, the heating energy quantity (P) per area of the reheating region (5a) of the third step is regulated in accordance with a depth characteristic formula for the scribe crack (5b).