PB-FREE SOLDER-CONNECTED STRUCTURE AND ELECTRONIC DEVICE

摘要

A Pb-free solder-connected structure having a sufficiently large connection strength, featuring an interface that remains stable even after the passage of time, and maintaining sufficient wettability and resistance against whiskers, and an electronic device. Specifically, a Pb-free solder, characterized in that an Sn-Ag-Bi solder which is a representative Pb-free solder is connected to an electrode that has an Sn-Bi layer formed on the surface thereof. Bi concentration in the Sb-Bi layer is preferably 1 to 20 % by weight to obtain a sufficient degree of wettability. When a more reliable joint is required, the Cu layer is formed under the Sn-Bi layer to obtain a connection portion having a sufficiently large interfacial strength.