The invention relates to a method for introducing weaknesses into a decorative material comprising a decorative layer and a carrier layer, preferably used for airbag coverings in motor vehicles, wherein the method comprises the following steps: a) introducing different weaknesses (21) by means of a laser (20) into sections (30) of the decorative material (10) for test purposes, wherein the different weaknesses (21) differ from one another in that the different weaknesses (21) are introduced using different parameters of the laser (20); b) measuring the tear properties of the sections (30); c) determining which section (30) which has a desired tear property and associating the relevant parameters of the laser (20) with this section (30); d) setting the laser (20) at the parameters associated in accordance with e); e) introducing weaknesses (22) into the decorative material (10) by means of the laser (20) set in accordance with step e).

Provided is a laser processing method for drilling a hole in a glass substrate with using a carbon dioxide laser, including the steps of: irradiating the laser onto a drilling position on the glass substrate from a side of the glass substrate on which a protective sheet is adhered so as to form a blind hole; removing the protective sheet from the glass substrate and performing an annealing treatment; and performing a wet-etching process on a side of the glass substrate not irradiated with the laser so as to convert the blind hole into a through hole.

Provided is a laser processing method for drilling a hole in a glass substrate with using a carbon dioxide laser, including the steps of: irradiating the laser onto a drilling position on the glass substrate from a side of the glass substrate on which a protective sheet is adhered so as to form a blind hole; removing the protective sheet from the glass substrate and performing an annealing treatment; and performing a wet-etching process on a side of the glass substrate not irradiated with the laser so as to convert the blind hole into a through hole.

Provided is a multi-junction solar cell in which two or more absorption layers having different bandgaps are stacked on one another. The multi-junction solar cell includes a first cell including a first absorption layer, and a second cell electrically connected in series onto the first cell, wherein the second cell includes a second absorption layer having a higher bandgap compared to the first absorption layer, and a plurality of recesses penetrating through the second absorption layer.

A metallic ball pen tip for a writing instrument comprising a feeding passage extending in an axial direction, the feeding passage reaching in a recess configured to receive a ball, the recess being defined by a cylindrical wall and a ball seat, wherein the ball seat comprises a plurality of feeding grooves and wherein the ball seat is textured, the texture comprising a plurality of blind holes having a depth equal to or smaller than 50 μm, preferably equal to or smaller than 10 μm, more preferably equal to or smaller than 5 μm, more preferably equal to or smaller than 1 μm, the blind holes having a total surface equal to or greater than 20% of the ball seat, preferably 60% and equal to or smaller than 90% of the ball seat, preferably 85%. A method of manufacturing a metallic ball pen tip.

A metallic ball pen tip for a writing instrument comprising a feeding passage extending in an axial direction, the feeding passage reaching in a recess configured to receive a ball, the recess being defined by a cylindrical wall and a ball seat, wherein the ball seat comprises a plurality of feeding grooves and wherein the ball seat is textured, the texture comprising a plurality of blind holes having a depth equal to or smaller than 50 μm, preferably equal to or smaller than 10 μm, more preferably equal to or smaller than 5 μm, more preferably equal to or smaller than 1 μm, the blind holes having a total surface equal to or greater than 20% of the ball seat, preferably 60% and equal to or smaller than 90% of the ball seat, preferably 85%. A method of manufacturing a metallic ball pen tip.

A method for producing a cavity in a substrate composed of hard brittle material is provided. A laser beam of an ultrashort pulse laser is directed a side surface of the substrate and is concentrated by a focusing optical unit to form an elongated focus in the substrate. Incident energy of the laser beam produces a filament-shaped flaw in a volume of the substrate. The filament-shaped flaw extends into the volume to a predetermined depth and does not pass through the substrate. To produce the filament-shaped flaw, the ultrashort pulse laser radiates in a pulse or a pulse packet having at least two successive laser pulses. After at least two filament-shaped flaws are introduced, the substrate is exposed to an etching medium which removes material of the substrate and widens the at least two filament-shaped flaws to form filaments. At least two filaments are connected to form a cavity.

Low-cost and robust platforms are key for the development of next-generation 3D micro- and nanodevices. To fabricate such platforms, nanocrystalline diamond (NCD) is a highly appealing material due to its biocompatibility, robustness, and mechanical, electrical, electrochemical, and optical properties, while glass substrates with through vias are ideal interposers for 3D integration due to the excellent properties of glass. A low-cost process—free of photolithography and transfer printing—for fabricating arrays of TGVs that are sealed with suspended portions of an ultra-thin NCD film on one side is presented. These highly transparent structures may serve as a platform for the development of microwells for single-cell culture and analysis, 3D integrated devices such as microelectrodes, and quantum technologies. It is also possible to replace the NCD with silicon nitride or silicon carbide, allowing for the development of complex heterogeneous structures on a small scale.

Provided is a laser processing method for performing laser processing on a printed circuit board by using a carbon dioxide laser oscillator that oscillates a laser by applying an RF pulse, including continuing laser oscillation by restarting an RF pulse application while a laser after completing the RF pulse application is output, cutting off the continuously oscillated laser for a desired time, and performing laser processing on the printed circuit board.

In an embodiment is provided a method of forming a blind via in a substrate comprising a mask layer, a conductive layer, and a dielectric layer that includes conveying the substrate to a scanning chamber; determining one or more properties of the blind via, the one or more properties comprising a top diameter, a bottom diameter, a volume, or a taper angle of about 80° or more; focusing a laser beam at the substrate to remove at least a portion of the mask layer; adjusting the laser process parameters based on the one or more properties; and focusing the laser beam, under the adjusted laser process parameters, to remove at least a portion of the dielectric layer within the volume to form the blind via. In some embodiments, the mask layer can be pre-etched. In another embodiment is provided an apparatus for forming a blind via in a substrate.