Abstract: There is provided a wiring substrate including an electrode including Cu or a Cu alloy, a plating film having a film including at least Pd, formed on the electrode, and a solder which is bonded onto the plating film by heating, has a melting point of lower than 140° C., and includes Pd dissolved therein, a Pd concentrated layer being absent between the solder and the electrode.

Abstract: A wiring substrate includes an electrode including Cu or a Cu alloy, and a plated film including an electroless nickel-plated layer formed on the electrode and an electroless gold-plated layer formed on the electroless nickel-plated layer. The electroless nickel-plated layer is formed by co-precipitation of Ni, P, Bi, and S, the electroless nickel-plated layer includes a content of P of 5% by mass or more and less than 10% by mass, a content of Bi of 1 ppm by mass to 1,000 ppm by mass, and a content of S of 1 ppm by mass to 2,000 ppm by mass, and a mass ratio of the content of S to the content of Bi (S/Bi) is more than 1.0.

Abstract: Provided is flux composition for a solder, which thermally cures so as to cover and reinforce a solder ball during solder ball bonding. Employed is a flux for soldering, containing an epoxy resin, an organocarboxylic acid containing at least 0.1-40 mass % of a dicarboxylic acid having molecular weight of 180 or less, and a thixotropy-imparting agent, the epoxy resin and the organocarboxylic acid being blended such that there is 0.8-2.0 eq of the carboxyl groups of the organocarboxylic acid per 1.0 eq of the epoxy groups of the epoxy resin, and the epoxy resin, the organocarboxylic acid, and the thixotropy-imparting agent being contained in a total amount of 70 mass % or more relative to the total amount of the flux.

Abstract: A wiring substrate includes an electrode including Cu or a Cu alloy, and a plated film including an electroless nickel-plated layer formed on the electrode and an electroless gold-plated layer formed on the electroless nickel-plated layer. The electroless nickel-plated layer is formed by co-precipitation of Ni, P, Bi, and S, the electroless nickel-plated layer includes a content of P of 5% by mass or more and less than 10% by mass, a content of Bi of 1 ppm by mass to 1,000 ppm by mass, and a content of S of 1 ppm by mass to 2,000 ppm by mass, and a mass ratio of the content of S to the content of Bi (S/Bi) is more than 1.0.

Abstract: Lead-free solder metal powder material including two or more metals capable of forming an intermetallic compound and having an unreacted phase and an amorphous phase. Further, a lead-free solder paste is prepared by mixing the powder material with a soldering flux. The powder material is preferably formed using a mechanical milling process.

Abstract: Lead-free solder metal powder material including two or more metals capable of forming an intermetallic compound and having an unreacted phase and an amorphous phase. Further, a lead-free solder paste is prepared by mixing the powder material with a soldering flux. The powder material is preferably formed using a mechanical milling process.

Abstract: Lead-free solder metal powder material including two or more metals capable of forming an intermetallic compound and having an unreacted phase and an amorphous phase. Further, a lead-free solder paste is prepared by mixing the powder material with a soldering flux. The powder material is preferably formed using a mechanical milling process.