| 摘要 |
PROBLEM TO BE SOLVED: To efficiently cut a dam bar and obtain a high-quality semiconductor device with high precision inhibiting attachment of dross, by cutting the dam bar with the emission of a laser beam in the form of pulse having a prolonged cross section, while jetting an assist gas from a gas nozzle. SOLUTION: A laser beam 21 having a circular cross section to form a hole 5 in a dam inner range 4 is oscillated from a laser oscillator 20, and emitted as a laser beam 51 on the dam inner range 4, forming the hole 5 there. Thereafter, the laser beam 11 to cut a dam bar 3 is oscillated from a laser oscillator 10, converted into a beam having a slim and oval cross section, and emitted as a laser beam 50 on the dam bar 3. The laser beam cuts the dam 3. Since the hole 5 is formed at the center of the dam inner range 4 prior to cutting the dam bar 3, the assist gas is accurately and effectively applied around the dam bar 3 when the dam bar 3 is cut by the laser beam 50. |
