Other

Tanaka Denki Kogyo Kabushiki Kaisha

Takatoshi Arikawa

Toshinori Ogashiwa

Masami Yokozawa

Yoshiharu Sawada

Kazuhiro Aoi

This invention provides a lead-free high temperature solder material comprising 0.005-3.0 wt % of palladium (Pd) and 97.0-99.995 wt % of tin (Sn) whose liquidus temperature is 200-350&deg; C. The solder material is environmentally-friendly, improved in thermal fatigue property, and it can improve the reliability of electronic apparatuses. A predetermined amount of Sn material and Pd is mixed, vacuum-melted and cast to prepare an ingot. The ingot is rolled to be a tape that is later pressed to obtain a solder pellet. In a preferable composition, at least 95 wt % of Sn and 0.005-3.0 wt 5 of Pd are contained, and 0.1-5.0 wt % of metallic (e.g. Cu, Ni) or alloy particles are added. The average particle diameter is about 40 &mgr;m. A substrate and an IC chip (electronic element) are die-bonded substantially in parallel by a solder material provided between an Ni plating on the lower side of an IC chip (semiconductor) and an Ni plating on a die.

Solder material and electronic part using the same

An object of this invention is to provide a solder material capable of, when joining an electronic component to a substrate with the solder material, improving heat fatigue resistance thereof and reducing damage of Ni film interposed therebetween. A solution of this invention is to assemble an electronic part by soldering a semiconductor device with a substrate using solder balls made of a solder material containing from 0.01 to 4.99% by weight of Fe; from 0.01 to 4.99% by weight of Ni, total thereof being from 0.02 to 5.0% by weight; from 0.1 to 8.0% by weight of at least one of Ag and In; from 0 to 70% by weight of Pb, balance containing Sn and unavoidable impurity.

Growing community of inventors

Tokyo, Japan

Takatoshi Arikawa