Patent ID: 9186750
Filing Date: 2015-11-17
Classification: B23K

Abstract:
1. A laser processing apparatus comprising: a chuck table for holding a workpiece; laser beam applying means for applying a laser beam to said workpiece held on said chuck table, said laser beam applying means including laser beam oscillating means for oscillating a laser beam, focusing means for focusing said laser beam oscillated by said laser beam oscillating means and applying said laser beam focused to said workpiece held on said chuck table, and a laser beam branching mechanism provided between said laser beam oscillating means and said focusing means for branching said laser beam oscillated by said laser beam oscillating means into a plurality of laser beams; and feeding means for relatively moving said chuck table and said laser beam applying means in a feeding direction; said laser beam branching mechanism including a branching unit for branching said laser beam oscillated by said laser beam oscillating means into said plurality of laser beams; said branching unit including a half-wave plate for 45° rotating the polarization plane of said laser beam oscillated by said laser beam oscillating means, a first polarization beam splitter for separating said laser beam passed through said half-wave plate into P polarized light and S polarized light, a first mirror for reflecting said P polarized light obtained by said first polarization beam splitter, a second mirror for reflecting said S polarized light obtained by said first polarization beam splitter, a second polarization beam splitter for leading said P polarized light reflected by said first mirror and said S polarized light reflected by said second mirror to different optical paths extending in the same direction, and angle adjusting means for adjusting the angle of reflection of at least one of said P polarized light and said S polarized light to be reflected by said first and second mirrors; whereby the angle of reflection of at least one of said P polarized light and said S polarized light to be reflected by said first and second mirrors is adjusted by said angle adjusting means to thereby adjust the spacing between the focal points of said plurality of laser beams formed by said P polarized light and said S polarized light to be focused by said focusing means.