Patent ID: 6677553
Filing Date: 2004-01-13
Classification: B23K,B32B,C04B,H01L,H05K

Abstract:
A laser processing apparatus comprising:a stage for mounting a workpiece, which moves said workpiece in the directions of two axes which are in parallel with said workpiece, said two axes being perpendicular to one other; a laser optical unit placed above said stage, for irradiating said workpiece mounted on said stage with laser light; a stage controller for controlling the movement of said stage in each direction of said two axes; said laser optical unit including: a light source for emitting laser light; at least one collecting lens for collectin laser light emitted from said light source and irradiating said workpiece with the laser light; a casing for placing at least said at least one collecting lens on an optical path of the laser light; a driving unit for moving said casing in a direction parallel to the optical path of the laser light; wherein said driving unit moves said casing and focuses the focal point of at least said at least one collecting lens on said workpiece; wherein said laser optical unit further includes: a second collecting lens for collecting laser light emitted from said light source and irradiating said workpiece, wherein a focal length of said at least one collecting lens is longer than a focal length of said second collecting lens; wherein said casing houses said at least on collecting lens and said second collecting lens, and either one of said at least one collecting lens and said second collecting lens is placed on the optical path of laser light, and said at least one collecting lens is placed at a longer distance from said workpiece than said second collecting lens, in said casing; a thickness measuring unit for measuring a thickness of said workpiece; and a setting unit for placing each of said at least one collecting lens and said second collecting lens on the optical path of laser light, in said casing; wherein said setting unit places either one of said at least one collecting lens and said second collecting lens on the optical path of laser light in accordance with the measured thickness of said workpiece.