Laser processing apparatus

A method of operating a laser processing apparatus, the laser apparatus comprising:

• a chuck table that holds a workpiece and includes a holding surface defined by an X-axis and a Y-axis;
• and
• a laser beam irradiation unit that irradiates the workpiece held by the chuck table with a laser beam and forms a broken layer, wherein
• the laser beam irradiation unit includes
• a laser oscillator that emits the laser beam,
• a Y-axis scanner that executes a high-speed scan with the laser beam emitted from the laser oscillator in a Y-axis direction,
• an X-axis scanner that executes processing feed of the laser beam emitted from the laser oscillator in an X-axis direction, and
• a beam condenser,
• wherein the beam condenser is configured to output a spot diameter (D) of the laser beam with which the workpiece is irradiated of 5 to 60 μm, wherein the beam condenser and the X-axis scanner are configured to output an overlap rate (K) of a spot of the laser beam of 0.70 to 0.99, wherein the Y-axis scanner is configured to output a scan speed (Vy) in the Y-axis direction of 1 to 300 m/s, and wherein the laser oscillator is configured to output an energy (E) of the laser beam per one pulse of 0.07 to 50 μJ,
• the method comprising the steps of:
• scanning the workpiece with the laser beam wherein
• a repetition frequency (H) of the laser beam is set to:
• H=Vy/{D·(1−K)} MHz,
• a scan speed (Vx) in the X-axis direction is set to:
• Vx=D·(1−K)·Vy/L mm/s,
• where a width of the scan by the Y-axis scanner is defined as L mm, and
• an average output power (P) of the laser beam is set to:
• P=E·Vy/{D·(1−K)} W.