Patent ID: 8871540

Claim:
A laser dicing method comprising: placing a workpiece substrate on a stage, the workplace substrate comprising a surface facing away from the stage; generating a clock signal; emitting a pulse laser beam synchronous with the clock signal, the pulse laser beam having a wavelength that enables the pulse laser beam to pass through the workpiece substrate; moving relatively the workpiece substrate and the pulse laser beam; switching irradiation and non-irradiation of the workpiece substrate with the pulse laser beam in a unit of light pulse in synchronization with the clock signal to perform first irradiation of the pulse laser beam on a first straight line by controlling passage and cutoff of the pulse laser beam using a pulse picker, the pulse laser beam being irradiated in a direction substantially perpendicular to the surface of the substrate in the first irradiation; switching the irradiation and non-irradiation of the workpiece substrate with the pulse laser beam in a unit of light pulse in synchronization with the clock signal to perform second irradiation of the pulse laser beam on a second straight line, the second straight line being adjacent and substantially parallel to the first straight line, by controlling the passage and cutoff of the pulse laser beam using the pulse picker after the first irradiation, the pulse laser beam being irradiated in a direction substantially perpendicular to the surface of the substrate in the second irradiation; and forming a crack reaching the workpiece substrate surface on the workpiece substrate by the first irradiation and the second irradiation, wherein the crack is continuously formed on the workpiece substrate surface by controlling irradiation energy of the pulse laser beam, a processing point depth of the pulse laser beam, and lengths of an irradiation region and a non-irradiation region of the pulse laser beam.