Laser method for machining through holes only in a ceramic green sheet, the latter provided with a carrier film

摘要

The present invention relates to a method for machining a ceramic green sheet (10) for forming a plurality of through holes on the ceramic green sheet (10), wherein a laser source (1) for emitting a pulse laser beam (2), a diffraction grating (3) for splitting the laser beam (2) into a plurality of laser beam components in the vicinity of the laser source (1), a galvano-scan mirror (4) that reflects the laser beam components at a reflection angle, a converging lens (5) that individually converges the laser beam components reflected by the galvano-scan mirror (4), and the ceramic green sheet (10) are disposed in a predetermined positional relationship. The laser beam (2) emitted from the laser source (1) is split through the diffraction grating (3) into the plurality of laser beam components (2a). The plurality of laser beam components (2a) is reflected with the galvano-scan mirror (4) toward the ceramic green sheet (10) such that a plurality of through holes is simultaneously formed at a predetermined location of a region of the ceramic green sheet (10). The reflection angle of the galvano-scan mirror (4) is changed to repeat reflection of the laser beam components (2a) until the through holes are formed in the region that can be processed by such a variation of the reflection angle in the ceramic green sheet (10). The ceramic green sheet (10) is shifted by a predetermined distance to another region and the reflection of the laser beam components (2a) and the change of the reflection angle of the galvano-scan mirror (4) is repeated until the through holes are formed at all regions of the ceramic green sheet (10). The ceramic green (10) sheet is provided with a carrier film (20) on one surface thereof, and the plurality of laser beam components has an energy that allows each of the plurality of laser beam components (2a) to penetrate through the ceramic green sheet (10) but not to penetrate through the carrier film (20).