| abstract |
[PROBLEMS] A Pb-free solder connection structure having sufficient connection strength, a stable interface over time, and sufficient wettability and whisker resistance. It is to provide a body and an electronic device. The present invention is characterized in that a Sn-Ag-Bi-based solder, which is effective as a Pb-free solder, is connected to an electrode having a Sn-Bi-based layer on the surface. This Sn-B The Bi concentration in the i-layer is preferably 1 to 2 to obtain sufficient wettability. It is desirably 0% by weight. Further, when a highly reliable joint is required, a connection portion having a sufficient interface strength is obtained by applying a Cu layer under the Sn-Bi layer. |