Laser processing apparatus

A laser processing 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 oscillates a laser,
• a Y-axis scanner that executes a high-speed scan with a 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,
• a spot diameter (D) of the laser beam with which the workpiece is irradiated is set to 5 to 60 μm, an overlap rate (K) of a spot of the laser beam is set to 0.70 to 0.99, a scan speed (Vy) in the Y-axis direction is set to 1 to 300 m/s, and energy (E) of the laser beam per one pulse is set to 0.07 to 50 μJ,
• repetition frequency (H) of the laser beam is set to
• H=Vy/{D·(1−K)} MHz,
• when a width of the scan by the Y-axis scanner is defined as L mm, a scan speed (Vx) in the X-axis direction is set to
• Vx=D·(1−K)·Vy/L mm/s, and
• average output power (P) of the laser beam is set to
• P=E·Vy/{D·(1−K)} W.