Composite sheet, machining method for composite sheet and laser machining apparatus

摘要

A composite sheet whose product price can be reduced with a smaller number of manufacturing processes. A laser oscillator outputs a pulsed beam at a frequency <U STYLE="SINGLE">f. A mask shapes the outer shape of the beam into a triangular, quadrangular or hexagonal shape. N pieces of time-sharing means time-share the beam to form N beams having a frequency f/N. N pairs of positioning means position the time-shared beams. A condensing lens condenses the beams. A rotating drum displaces a workpiece. A control means controls the time-sharing means, the N pairs of positioning means and a pedestal. The N pairs of positioning means are positioned to irradiate predetermined positions with the beams. The pedestal is moved. The time-sharing means are thereupon operated in predetermined order. The workpiece is machined to make holes whose outer shapes depend on the mask so that distances between sides of adjacent holes are equal to one another.