Laser beam machining method

摘要

A laser material processing method for processing a printed wiring board to form a blind hole, a groove or a through hole by applying a laser beam to an insulating layer of the printed wiring board includes a first step of processing the insulating layer at a predetermined energy density, a second step of hardening the insulating layer by applying a laser beam at a lower energy density than the predetermined energy density of the first step around a processed portion processed in the first step, and a third step of removing the residual smear.