Abstract: Provided is a laser irradiation device for use in laser processing, and a laser processing method performed using the same. Provided is a laser irradiation device including: a light source that emits a laser beam; and an irradiation optical system which has one or a plurality of lenses, and is provided for light-guiding and light-converging of the laser beam emitted from the light source to the target substance, in which a birefringent material is used as a material entity of at least one lens of the irradiation optical system. Also provided is a laser processing method. The irradiation optical system may have a beam expander having a first lens that is a concave lens or a convex lens, and a second lens that is a convex lens, in the order along the laser-beam travel direction, the beam expander being configured so as to make the interval between the first lens and the second lens variable, in which a birefringent material may be used as a material entity of the first lens and/or the second lens.

Abstract: A laser scribe processing method of forming a crack that runs along a scribe direction of a processing target substance uses a light source that emits a laser beam, and an optical system for irradiation that leads the laser beam onto the processing target substance, the method including: an emission step of emitting a laser beam from the light source; a splitting step of splitting the laser beam into an ordinary light component and an extraordinary light component having different travel directions; a light converging step of converging the ordinary light component and the extraordinary light component to form multiple pairs of beam spots; and an irradiation step of intermittently irradiating with the laser beam having multiple pairs of beam spots in a scribe direction of the processing target substance. For splitting the ordinary light component and the extraordinary light component in the splitting step, a birefringent prism disposed in the optical system for irradiation may be used.

Abstract: To form a deeper scribed groove with less energy or to improve the scribing speed, without making the apparatus configuration complicated is intended. The present invention relates to a laser scribing method which includes: forming on a workpiece a plurality of beam spots arranged in a state being separated from one another along the scribing direction, and forming a linear scribed groove on the workpiece by moving the plurality of beam spots in the scribing direction. The plurality of beam spots are obtained from a laser beam of a single ray bundle.

Abstract: Provided is a laser irradiation device for use in laser processing, and a laser processing method performed using the same. Provided is a laser irradiation device including: a light source that emits a laser beam; and an irradiation optical system which has one or a plurality of lenses, and is provided for light-guiding and light-converging of the laser beam emitted from the light source to the target substance, in which a birefringent material is used as a material entity of at least one lens of the irradiation optical system. Also provided is a laser processing method. The irradiation optical system may have a beam expander having a first lens that is a concave lens or a convex lens, and a second lens that is a convex lens, in the order along the laser-beam travel direction, the beam expander being configured so as to make the interval between the first lens and the second lens variable, in which a birefringent material may be used as a material entity of the first lens and/or the second lens.