Patent ID: 7355157

Claim:
A laser beam processing machine comprising a chuck table for holding a workpiece, a laser beam application means for applying a laser beam to the workpiece held on the chuck table, and a processing-feed means for moving the chuck table and the laser beam application means relative to each other, the laser beam application means comprising a laser beam oscillation means and a condenser for converging a laser beam oscillated from the laser beam oscillation means into a converged laser beam to apply the converged laser beam to the workpiece, wherein the condenser comprises a first prism for splitting the laser beam oscillated from the laser beam oscillation means into a first laser beam and a second laser beam each having a semicircular section with an arcuate portion in an inner side and a linear portion in an outer side and for interchanging the first laser beam with the second laser beam, a second prism for correcting optical paths of the first laser beam and the second laser beam split by the first prism to become parallel to each other, and an image forming lens for focusing the first laser beam and the second laser beam whose optical paths have been corrected parallel by the second prism to form on the workpiece a pair of beam spots having linear portions on the outer side and arcuate portions on the inner side; and the image forming lens is configured to direct the first laser beam and the second laser beam to cause said beam spots to partially overlap each other to form a substantially rectangular combined spot in which the inner arcuate portions of the beam spots overlap each other.