A process for room temperature substrate bonding employs a first substrate substantially transparent to a laser wavelength is selected. A second substrate for mating at an interface with the first substrate is then selected. A transmissivity change at the interface is created and the first and second substrates are mated at the interface. The first substrate is then irradiated with a laser of the transparency wavelength substantially focused at the interface and a localized high temperature at the interface from energy supplied by the laser is created. The first and second substrates immediately adjacent the interface are softened with diffusion across the interface to fuse the substrates.

Provided is a welding method enabling enhancement of quality of welding between an upper plate and a lower plate. One aspect of the present disclosure is the welding method including welding the upper plate and the lower plate overlapped with the upper plate by irradiating a surface of the upper plate with a laser beam. The welding includes: forming an auxiliary welding path that is continuous and includes a reciprocating or circling path; and forming a main welding path that intersects a welding advancing direction and that includes turning points, after formation of the auxiliary welding path.

A method and associated device for joining a battery cell tab to a plurality of foils associated with a plurality of electrodes of a battery cell are described. This includes arranging the plurality of foils in a stack, and joining, via a first joining device, the plurality of foils, wherein the first joining device defines a joining region. A portion of the battery cell tab is arranged on the plurality of foils, and joined, via a second joining device, to the plurality of foils. The second joining device generates a weld joint that is encompassed within the joining region defined by the first joining device. In doing so, weld quality and strength of internal welds in a battery cell may be improved by reducing the occurrence of porosities and cracks in the foil/tab weld joints.

A laser welding method is provided to ensure a sufficient joining strength between metal plates by increasing the area of a joining region while preventing “burn through” of a molten metal. In the laser welding method by applying a laser beam to a surface of multiple metal plates superimposed on each other, a scanning locus with the laser beam is sequentially shifted from an inner circular scanning locus to an outer one in a predetermined joining region on the metal plates, and an emission interval is provided to temporally stop the metal-plate-surface irradiation when the scanning locus is shifted. Thus, every time the scanning locus is shifted, the molten metal due to the previous irradiation is cooled and increases its viscosity. Accordingly, the “burn through” is prevented regardless of increase of the area of the joining region, which results in a sufficient joining strength between the metal plates.

The present invention relates to a secondary battery capable of improving the coupling force between a safety vent and a cap-up. For example, disclosed is a secondary battery comprising: an electrode assembly; a case for accommodating the electrode assembly; a cap assembly coupled to the upper part of the case; and a gasket interposed between the cap assembly and the case, wherein the cap assembly includes a cap-up and a safety vent, which is provided at the lower part of the cap-up and has a vent extension part extending to the upper part of the cap-up so as to encompass the edge of the cap-up, a welding region, in which the safety vent and the cap-up are welded and coupled by laser welding, is formed in the vent extension part, and the welding region is formed in a line shape.

Metallization of semiconductor substrates using a laser beam, and the resulting structures, e.g., micro-electronic devices, semiconductor substrates and/or solar cells, solar cell circuit, solar cell strings, and solar cell arrays are described. A solar cell string can include a plurality of solar cells. The plurality of solar cells can include a substrate and a plurality of semiconductor regions disposed in or above the substrate. A plurality of conductive contact structures is electrically connected to the plurality semiconductor regions. Each conductive contact structure includes a locally deposited metal portion disposed in contact with a corresponding one of the semiconductor regions.

A multi-tubular beam for a vehicle, such as a vehicle structure or a bumper reinforcement, includes an elongated beam formed with a metal sheet. The metal sheet has a central section and outer sections extending along a length of the metal sheet. The outer sections are disposed in opposing directions from the outer edges of the central section to provide adjacent first and second tubular portions. The central section forms a common center wall between the adjacent first and second tubular portions. A first edge portion of the metal sheet is disposed along and in parallel alignment with the center wall. The first edge portion is attached to the center wall at a first weld joint to form the first tubular portion. The first weld joint includes a weld material that extends through a thickness of the center wall and into a thickness of the first edge portion.

A welding method includes performing welding by emitting laser light moving in a sweeping direction relatively to a processing object onto a surface of the processing object to melt a portion of the processing object onto which the laser light is emitted, wherein the laser light includes: first laser light having a wavelength equal to or larger than 800 nm and equal to or smaller than 1200 nm; and second laser light having a wavelength equal to or smaller than 550 nm.

A manufacturing method for a joint body having a first metal member and a second metal member joined together by causing a laser oscillation system to irradiate a surface of the second metal member placed on the first metal member with laser light to form a joint portion including a welded portion where the first metal member and the second metal member are joined together includes continuously supplying the second metal member while pressing the second metal member against the first metal member, the second metal member being a hoop material, and causing the laser oscillation system to emit the laser light.

A method of analyzing a welded connection during laser welding of workpieces includes acquiring a first measurement signal for a process radiation generated during laser welding, acquiring a second measurement signal for a laser radiation reflected by the workpieces, determining whether there is a gap between the workpieces based on the first measurement signal, and when it is determined that there is a gap, determining based on the second measurement signal whether there is a welded connection.