| 摘要 |
A laser processing method having: a first piercing step wherein a non-penetrating piercing hole running from the top surface of a workpiece (W) to the central portion thereof is formed; a cooling step wherein the workpiece (W) is cooled; a second piercing step wherein the piercing hole is formed through to the bottom surface of the workpiece; and a cutting step wherein the workpiece is cut. In the second piercing step the piercing process is performed by irradiating the workpiece (W) with a laser beam (L) while changing from a state in which the output of the laser beam (L) is set to a second output value smaller than a first output value, the focal position is set to a first in-focus position, the focal depth is set to a second depth larger than a first depth, and a side gas blowing pressure is set to a second pressure value smaller than a first pressure value, to a state wherein the output of the laser beam (L) is set to a third output value smaller than the first output value and larger than the second output value, the focal position is set to a second in-focus position having a larger in-focus amount than the first in-focus position, and the focal depth is set to a third depth larger than the second depth. Thus, self-burning during beam irradiation is suppressed, and the time required for the piercing process is reduced. |
