LASER PROCESSING METHOD AND LASER PROCESSING APPARATUS

摘要

An ultra-short pulse laser beam output from a laser is diffracted into a plurality of laser beams, and a nozzle plate is scanned with the laser beams at a scanning speed of 40 mum/s to 300 mum/s. A placement position z of the nozzle plate with respect to a direction of an optical path of each laser beam is set to be -20 mum to +25 mum, where z is 0 at a reference position at which a hole diameter of the nozzle is minimum, and z increases as the placement position is moved closer to a source of the laser beam and decreases as the placement position is moved away from the source of the laser beam.