Laser dicing method

A laser dicing method which comprises:

• setting a work piece on a stage;
• generating a clock signal;
• emitting a pulse laser beam synchronized with the clock signal;
• relatively moving the work piece and the pulse laser beam;
• switching irradiation and non-irradiation of the pulse laser beam on the work piece in light pulse units by controlling passing and blocking of the pulse laser beam using a pulse picker in synchronization with the clock signal;
• and
• forming a crack reaching a substrate surface of the work piece to be continuous in the substrate surface of the work piece by controlling irradiation energy of the pulse laser beam, a process point depth of the pulse laser beam and lengths of an irradiation area and a non-irradiation area of the pulse laser beam, the laser dicing method comprising:
• a first crack forming of irradiating the pulse laser beam on the work piece along a first line;
• and
• a second crack forming of irradiating the pulse laser beam on the work piece along a second line orthogonal to the first line,
• wherein, in an area in which the first line and the second line cross, a light pulse density of the pulse laser beam is increased in the first crack forming or the second crack forming.