Laser beam processing method and laser beam processing machine

摘要

A laser beam processing method comprising holding a plate-like workpiece having dividing lines formed in a lattice pattern on the front surface on a chuck table and applying a laser beam capable of passing through the plate-like workpiece to the plate-like workpiece held on the chuck table along the dividing lines to form a deteriorated layer in the inside of the plate-like workpiece along the dividing lines, wherein a height position detection step of detecting the position of a height of the surface on the side to which the laser beam is applied, of the plate-like workpiece held on the chuck table along a dividing line; and a laser beam application step of applying a laser beam to the workpiece along the dividing line while controlling the position of the focusing point of the laser beam corresponding to the position of the height detected in the height position detection step.