Solder alloy material layer composition, electroconductive and adhesive composition, flux material layer composition, solder ball transferring sheet, bump and bump forming process, and semiconductore device

摘要

An object of the present invention is to provide solder bumps sufficiently satisfying the expected functions and having a small diameter which conventional methods cannot attain, a semiconductor device on which these bumps are mounted, and a bump transferring sheet. The present invention provides a method for forming the bumps, which includes forming a solder alloy material layer and flux material layer one by one on an intermediate metallic layer formed on an external electrode pad in a semiconductor device, and then fusing these layers, wherein each of the solder alloy material layer and flux material layer is formed by a liquid spraying method (e.g., ink jetting method).