An apparatus and method of fabricating particles composed of metals, conducting polymers, semiconductors, and composites of such materials are provided. The method includes application of an editing tool, such as a laser, for patterning an editable structure that mounted on an electrically conductive substrate. Portions of the editable structure may be removed so as to allow electrodeposition.

A method for separating a workpiece along a separation line by using laser pulses of a laser beam includes splitting the laser beam into a plurality of partial laser beams using a beam splitter optical unit, focusing the plurality of partial laser beams onto a surface of the workpiece and/or into a volume of the workpiece using a focusing optical unit, so that the plurality of partial laser beams are arranged next to one another and spaced apart from one another along the separation line, and ablating material of the workpiece along the separation line by introducing the laser pulses of the plurality of partial laser beams into the workpiece. The laser power per partial laser beam is adjusted depending on an ablation depth obtained in the workpiece.

To form linear grooves of desired groove width on a metal strip surface and provide a grain-oriented electrical steel sheet having excellent magnetic properties, a linear groove formation method comprises: forming a resist coating on at least one surface of a metal strip; thereafter irradiating the resist coating with a laser while scanning the laser in a direction crossing a rolling direction of the metal strip, to remove the resist coating in a part irradiated with the laser; and thereafter performing etching treatment to form a linear groove in a part of the metal strip in which the resist coating is removed, wherein the resist coating contains a predetermined amount of an inorganic compound, and on the surface of the metal strip, the laser has a predetermined elliptic beam shape.

To form linear grooves of desired groove width on a metal strip surface and provide a grain-oriented electrical steel sheet having excellent magnetic properties, a linear groove formation method comprises: forming a resist coating on at least one surface of a metal strip; thereafter irradiating the resist coating with a laser while scanning the laser in a direction crossing a rolling direction of the metal strip, to remove the resist coating in a part irradiated with the laser; and thereafter performing etching treatment to form a linear groove in a part of the metal strip in which the resist coating is removed, wherein the resist coating contains a predetermined amount of an inorganic compound, and on the surface of the metal strip, the laser has a predetermined elliptic beam shape.

A grain-oriented electrical steel sheet according to the present invention has a steel sheet surface provided with grooves. An average protrusion height of the surface protrusion extending along a longitudinal direction of the groove is more than 5 μm and not more than 10 μm. When the surface protrusion is viewed in a cross section including the longitudinal direction of the groove and a normal direction of the steel sheet surface, the surface protrusion includes specific portions each having a height of 50% or more with respect to a height of each peak point appearing on a profile line of the surface protrusion. In the longitudinal direction of the groove, the total length of the specific portions is a length of 30% or more with respect to an overall length of the surface protrusion.

A grain-oriented electrical steel sheet according to the present invention has a steel sheet surface provided with grooves. An average protrusion height of the surface protrusion extending along a longitudinal direction of the groove is more than 5 μm and not more than 10 μm. When the surface protrusion is viewed in a cross section including the longitudinal direction of the groove and a normal direction of the steel sheet surface, the surface protrusion includes specific portions each having a height of 50% or more with respect to a height of each peak point appearing on a profile line of the surface protrusion. In the longitudinal direction of the groove, the total length of the specific portions is a length of 30% or more with respect to an overall length of the surface protrusion.

A manufacturing process of an element chip comprises a preparing step for preparing a substrate having first and second sides opposed to each other, the substrate containing a semiconductor layer, a wiring layer and a resin layer formed on the first side, and the substrate including a plurality of dicing regions and element regions defined by the dicing regions. Also, the manufacturing process comprises a laser grooving step for irradiating a laser beam onto the dicing regions to form grooves so as to expose the semiconductor layer along the dicing regions. Further, the manufacturing process comprises a dicing step for plasma-etching the semiconductor layer along the dicing regions through the second side to divide the substrate into a plurality of the element chips. The laser grooving step includes a melting step for melting a surface of the semiconductor layer exposed along the dicing regions.

A manufacturing process of an element chip comprises a preparing step for preparing a substrate having first and second sides opposed to each other, the substrate containing a semiconductor layer, a wiring layer and a resin layer formed on the first side, and the substrate including a plurality of dicing regions and element regions defined by the dicing regions. Also, the manufacturing process comprises a laser grooving step for irradiating a laser beam onto the dicing regions to form grooves so as to expose the semiconductor layer along the dicing regions. Further, the manufacturing process comprises a dicing step for plasma-etching the semiconductor layer along the dicing regions through the second side to divide the substrate into a plurality of the element chips. The laser grooving step includes a melting step for melting a surface of the semiconductor layer exposed along the dicing regions.

A laser beam applying unit of a laser processing apparatus for processing a wafer includes a laser oscillator for emitting a pulsed laser beam having a wavelength transmittable through the wafer, a beam condenser for converging the pulsed laser beam emitted from the laser oscillator onto the wafer held on a chuck table, a beam splitter assembly disposed between the laser oscillator and the beam condenser, for splitting the pulsed laser beam emitted from the laser oscillator to form at least two converged spots on the wafer that are spaced from each other in X-axis directions, and a mask assembly disposed between the laser oscillator and the beam condenser, for reducing the width of the converged spots on the wafer in Y-axis directions to keep the converged spots on the wafer within the width of the projected dicing lines on the wafer.

A laser beam applying unit of a laser processing apparatus for processing a wafer includes a laser oscillator for emitting a pulsed laser beam having a wavelength transmittable through the wafer, a beam condenser for converging the pulsed laser beam emitted from the laser oscillator onto the wafer held on a chuck table, a beam splitter assembly disposed between the laser oscillator and the beam condenser, for splitting the pulsed laser beam emitted from the laser oscillator to form at least two converged spots on the wafer that are spaced from each other in X-axis directions, and a mask assembly disposed between the laser oscillator and the beam condenser, for reducing the width of the converged spots on the wafer in Y-axis directions to keep the converged spots on the wafer within the width of the projected dicing lines on the wafer.