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

摘要

A plurality of feedthrough holes are efficiently formed on the present invention by splitting a laser beam emitted from a laser source (1) into plural laser beams (2) by allowing the beam to pass through a diffraction grating (3), followed by simultaneously forming a plurality of the feedthrough holes on the ceramic green sheet (10) by irradiating the ceramic green sheet (10) with the split laser beam.