Provided are a joint component formed with fine recessed portions so that degradation of the flatness of a metal base body, such as a core, to which a joint object such as a friction member is joined can be reduced, a multiplate clutch device including the joint component, and a joint component manufacturing method. At a friction plate (200) as the joint component, many fine recessed portions (204) are formed at a joint surface (203) as a portion of a core (201) joined to friction members (207). The joint surface (203) is formed in a circular ring shape along a peripheral direction of the core (201), and is formed with a flatness of equal to or less than 0.15 mm. The fine recessed portions (204) are formed at the joint surface (203) such that adjacent ones of the fine recessed portions (204) do not overlap with each other and a formation density per unit area (Ua) at the joint surface (203) is uniform. The fine recessed portions (204) are formed as laser processing marks formed at the core (201) by irradiation with laser light L.

A method of producing a glass substrate having a hole is provided. The method includes preparing the glass substrate having a first surface and a second surface facing each other; forming a hole in the glass substrate with a laser; and annealing the glass substrate placed on a first support substrate having a thermal expansion coefficient whose difference from a thermal expansion coefficient of the glass substrate is less than or equal to 1 ppm/K, where the first support substrate is placed on a second support substrate having a thermal expansion coefficient of less than or equal to 10 ppm/K.

The invention relates to laser equipment, specifically pulsed scanning lasers used to cut brittle substrates. The authors propose a method and device for forming a stressed edge in the substrate for cleaving of the substrate, to which end a track of cavities is formed through optically induced breakdown in the body of tire material during its irradiation with a focused laser beam with a fixed focal distance during the course of angled scanning of the laser beam, with longitudinal movement along the length of the substrate. The technical result is: improved strength parameters of products and better quality of straight and oblique edges formed during substrate cleaving, absence of chips and microcracks, high rate of formation of the stressed cleaving edge, which implies faster laser cutting.

A method for introducing at least one cutout, in particular in the form of an aperture, into a sheetlike workpiece having a thickness of less than 3 mm, involving detecting a laser beam onto the surface of the workpiece, selecting the exposure time of the laser beam to be extremely short so that only a modification of the workpiece concentrically around a beam axis of the laser beam occurs, such a modified region having defects resulting in a chain of blisters, and, as a result of the action of a corrosive medium, anisotropically removing material by successive etching in those regions of the workpiece that are formed by the defects and have previously been modified by the laser beam, resulting, along the cylindrical zone of action, in producing a cutout as an aperture in the workpiece.

A method and arrangement for the texturing of a moving steel strip wherein a texture is applied to a surface of a moving steel strip by ablation by means of a single laser beam or a plurality of laser beams directed at the surface of the moving steel strip and wherein a liquid is supplied on the moving steel strip over a surface area on the moving steel strip that covers the working area of the single laser beam or the plurality of laser beams on the moving steel strip.

A method of splitting a semiconductor work piece includes: forming a separation zone within the semiconductor work piece, wherein forming the separation zone comprises modifying semiconductor material of the semiconductor work piece at a plurality of targeted positions within the separation zone in at least one physical property which increases thermo-mechanical stress within the separation zone relative to a remainder of the semiconductor work piece, wherein modifying the semiconductor material in one of the targeted positions comprises focusing at least two laser beams to the targeted position; and applying an external force or stress to the semiconductor work piece such that at least one crack propagates along the separation zone and the semiconductor work piece splits into two separate pieces. Additional work piece splitting techniques and techniques for compensating work piece deformation that occurs during the splitting process are also described.

A wafer processing method includes a polyolefin sheet providing step of positioning a wafer in an inside opening of a ring frame and providing a polyolefin sheet on a back side or a front side of the wafer and on a back side of the ring frame, a uniting step of heating the polyolefin sheet as applying a pressure to the polyolefin sheet to thereby unite the wafer and the ring frame through the polyolefin sheet by thermocompression bonding, a dividing step of applying a laser beam to the wafer to form shield tunnels in the wafer, thereby dividing the wafer into individual device chips, and a pickup step of heating the polyolefin sheet, pushing up each device chip through the polyolefin sheet, and picking up each device chip from the polyolefin sheet.

A method for creating at least one recess, in particular an aperture, in a transparent or transmissive material, includes: selectively modifying the material along a beam axis by electromagnetic radiation; and creating the at least one recess by one or more etching steps, using different etching rates in a modified region and in non-modified regions. The electromagnetic radiation produces modifications having different characteristics in the material along the beam axis such that the etching process in the material is heterogeneous and the etching rates differ from one another in regions modified with different characteristics under unchanged etching conditions.

A femtosecond laser source according to an embodiment of the present invention includes: a pulse generator that converts a continuous wave laser into an optical pulse train; a burst generator that separates the optical pulse train into a plurality of burst pulses; a pulse amplification and spectral broadening unit that expands the spectrum by amplifying a plurality of burst pulses; and a pulse compressor that compresses a plurality of amplified burst pulses to generate a femtosecond laser with a pulse width of 1 picosecond (10.sup.−12 s) or less.

An optical processing apparatus, an optical processing method, and an optically-processed product production method. The optical processing apparatus and the optical processing method includes emitting a first process light to a focal point set inside an object to be processed, using a first light-emitting unit, and emitting a second process light during a period of time in which plasma or gas is generated inside the object to be processed, by the first process light, using a second light-emitting unit. The processed product production method includes emitting a first process light to a focal point set inside an object to be processed, using a first light-emitting unit, and emitting a second process light during a period in which plasma or gas is generated inside the object to be processed by the first process light, using a second light-emitting unit.