| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser processing method which can improve plating reliability, that is, reliability of a printed circuit board by making the axial length of a hole processed from the front face coaxial with that of a hole processed from the rear face.SOLUTION: In a laser processing method where a processing region determined by a size of a f&thetas; lens 13 is irradiated with laser beams with a scanner 12 and the f&thetas; lens 13 to form a through hole in a workpiece w, two sets of scanners 12 and the f&thetas; lenses 13 are provided to make the axes of the two f&thetas; lenses 13 coaxial, and a through hole is processed from both sides of the workpiece w. At this time, one laser beam may be shaped into a clockwise circular polarization laser beam, and the other laser beam may be shaped into a counterclockwise circular polarization laser beam. |
