Proposed is an epoxy flux film that is to be positioned between a semiconductor substrate and a device and is heated and pressed without addition of an additional flux. Thus, device-substrate soldering and sealing are simultaneously performed, and interference of light reflected from the solder can be reduced.

A method for formation of a patterned solder mask (10) on a substrate is provided, in which method the mask is deposited by a process of chemical deposition in vapor phase. A method for manufacturing a printed circuit board and/or an electronic component comprising formation of said patterned solder mask is further provided.

A welding system comprises a welding module and a moving module adapted to move the welding module to a predetermined welding position. The welding module includes a guiding device and a welding tool. The guiding device has a plurality of tubular guiding heads arranged in a row, ends of the plurality of tubular guiding heads are disposed close to joints of a plurality of cables so as to guide a plurality of welding wires to the joints of the plurality of cables. The welding tool has a plurality of tooth-shaped welding heads arranged in a row, ends of the plurality of tooth-shaped welding heads are disposed close to the joints of the plurality of cables and configured to simultaneously heat the plurality of welding wires guided to the joints of the plurality of cables, so as to simultaneously weld the joints of the plurality of cables onto a circuit board.

An electronic device having at least one circuit board. The circuit board has a predetermined pattern of solder bumps facilitating a ground connection with a first enclosure member and/or a second enclosure member. The at least one circuit board is sandwiched between the first and second enclosure members, each of the first and second enclosure members has a surface facing the circuit board and the surface facing the circuit board has a bead extending therefrom contacting the predetermined pattern of solder bumps to complete the ground connection.

A flexible printed circuit and a manufacturing method thereof, an electronic device module and an electronic device are provided. The flexible printed circuit includes a main sub-circuit board and a bridge sub-circuit board; the main sub-circuit board includes a first substrate, and a first bridge end, a second bridge end, a first wiring portion, and a second wiring portion on the first substrate, the first wiring portion and the second wiring portion are spaced apart from each other and are electrically connected to the first bridge end and the second bridge end, respectively; the bridge sub-circuit board includes a second substrate, and a third bridge end, a fourth bridge end, and a third wiring portion for a first functional wiring line on the second substrate, the third bridge end and the fourth bridge end are electrically connected by the third wiring portion, the first substrate and the second substrate are not in direct contact, and the bridge sub-circuit board is configured to be mounted on the main sub-circuit board by electrically connecting the third bridge end and the fourth bridge end to the first bridge end and the second bridge end, respectively. The wiring layout of the flexible printed circuit is simple and is easy to be manufactured.

A printed circuit board has a solder joint inspection system including a substrate surface having at least one solder pad thereon, at least one conductor wire having an end attached to the at least one solder pad, and a first inspection feature. A first inspection feature is marked on the substrate surface adjacent to the at least one solder pad to define a conductor end zone on the at least one solder pad. The end of the conductor wire is in the conductor end zone when properly attached. The at least one solder pad may define a second inspection feature to mark an extent to which the at least one solder pad is covered by a flow of solder when the wire is properly attached.

A solder alloy that contains 0.005 mass % or more and 0.1 mass % or less of Mn, 0.001 mass % or more and 0.1 mass % or less of Ge, and a balance of Sn. A plurality of Ge oxides is distributed on an outermost surface side of an oxide film including Sn oxide, Mn oxide and Ge oxide by adding 0.005 mass % or more and 0.1 mass % or less of Mn, 0.001 mass % or more and 0.1 mass % or less of Ge to the solder alloy having a principal ingredient of Sn, so that it is possible to obtain the discolor-inhibiting effect even under the high-temperature and high-humidity environment.

A resin flux solder paste includes a solder powder, and a flux, in which the flux contains at least an epoxy resin, a curing agent, a curing accelerator, and an activator, the epoxy resin contains 10% to 90% by weight of one or more of a biphenyl aralkyl type epoxy resin, a naphthalene type epoxy resin, and a dicyclopentadiene type epoxy resin, having an epoxy equivalent of 200 to 400, with respect to a total amount of the epoxy resin, and the curing agent contains 30% to 95% by weight of a biphenyl aralkyl phenol resin having a hydroxyl group equivalent of 150 to 350 with respect to a total amount of the curing agent, and 5% to 70% by weight of a phenol novolac resin having an allyl group having a hydroxyl group equivalent of 100 to 200 with respect to the total amount of the curing agent.

A method for circuit fabrication includes defining a solder bump, including a specified solder material and having a specified bump volume, to be formed at a target location on an acceptor substrate. A transparent donor substrate, having a donor film including the specified solder material, is positioned such that the donor film is in proximity to the target location on the acceptor substrate. A sequence of pulses of laser radiation is directed to pass through the first surface of the donor substrate and impinge on the donor film so as to induce ejection from the donor film onto the target location on the acceptor substrate of a number of molten droplets of the solder material such that the droplets deposited at the target location cumulatively reach the specified bump volume. The target location is heated so the deposited droplets melt and reflow to form the solder bump.

Systems and methods in which dot-like portions of a material (e.g., a viscous material such as a solder paste) are printed or otherwise transferred onto an electronic component at a first printing unit, and the electronic component is subsequently placed onto a substrate with the portions of viscous material between the electronic component and the substrate. Optionally, a printing unit which prints the dots of material onto the electronic component includes a coating system that creates a uniform layer of the material on a donor substrate, and the material is transferred in the individual dot-like portions from the donor substrate onto the electronic component by the printing unit. The system may also include imaging units to aid in the overall process.