Laser processing apparatus and laser processing method

A laser processing apparatus which applies a laser beam to a workpiece having a crystal structure to perform laser processing on the workpiece, comprising:

• a holding unit including a holding surface for holding the workpiece having a first surface, a second surface, and a side surface that is connected to the first surface and the second surface;
• a laser oscillator which emits the laser beam;
• a beam condenser for focusing the laser beam emitted from the laser oscillator;
• a position adjusting unit which adjusts a positional relation between the holding unit and a focused spot of the laser beam;
• a first rotation mechanism which rotates the holding unit with a first rotational axis crossing the holding surface as a center;
• a second rotation mechanism which rotates the holding unit or the beam condenser with a second rotational axis crossing a direction parallel to the first rotational axis as a center;
• a crystal orientation information acquisition unit which acquires crystal orientation information for identifying a crystal orientation of the workpiece held on the holding unit;
• and
• a controller,
• wherein the controller applies the laser beam to the workpiece from a side of the first surface or the second surface in a state in which the beam condenser faces the first surface or the second surface of the workpiece and a position of the focused spot relative to the workpiece is adjusted according to the crystal orientation of the workpiece identified by the crystal orientation information, by controlling the position adjusting unit, the first rotation mechanism, and the second rotation mechanism.

A laser processing method comprising:

• holding a workpiece with a crystal structure having a first surface, a second surface, and a side surface connected to the first surface and the second surface on a holding surface of a holding unit;
• acquiring crystal orientation information for identifying a crystal orientation of the workpiece;
• adjusting a relative position and orientation between the holding unit and a beam condenser in such a manner that the beam condenser focusing a laser beam faces the side surface of the workpiece held on the holding unit;
• processing an outer peripheral portion of the workpiece into a predetermined shape by rotating the holding unit with a rotational axis crossing the holding surface as a center, while the laser beam is being applied to the workpiece held on the holding unit from the beam condenser that is caused to face the side surface of the workpiece;
• and
• forming a mark indicating a crystal orientation of the workpiece in the workpiece by adjusting a position of the focused spot of the laser beam relative to the workpiece, according to the crystal orientation of the workpiece identified by the crystal orientation information, and applying the laser beam to the workpiece held on the holding unit from the beam condenser that is caused to face the side surface of the workpiece.

A laser processing method comprising:

• holding a workpiece with a crystal structure having a first surface, a second surface, and a side surface connected to the first surface and the second surface on a holding surface of a holding unit;
• acquiring crystal orientation information for identifying a crystal orientation of the workpiece;
• adjusting a relative position and orientation between the holding unit and a beam condenser in such a manner that the beam condenser focusing a laser beam faces the side surface of the workpiece held on the holding unit;
• processing an outer peripheral portion of the workpiece into a predetermined shape by rotating the holding unit with a rotational axis crossing the holding surface as a center, while the laser beam is being applied to the workpiece held on the holding unit from the beam condenser that is caused to face the side surface of the workpiece;
• adjusting a relative position and orientation between the holding unit and the beam condenser in such a manner that the beam condenser faces the first surface or the second surface of the workpiece held on the holding unit;
• and
• forming a mark indicating a crystal orientation of the workpiece in the workpiece by adjusting a position of the focused spot of the laser beam relative to the workpiece, according to the crystal orientation of the workpiece identified by the crystal orientation information, and applying the laser beam to the workpiece held on the holding unit from the beam condenser that is caused to face the first surface or the second surface of the workpiece.