Solder alloys, solder pastes, solder balls, solder preforms, solder joints, in-vehicle electronic circuits, ECU electronic circuits, in-vehicle electronic circuit devices, and ECU electronic circuit devices.

摘要

PROBLEM TO BE SOLVED: To provide a solder alloy or the like capable of preventing adverse effects on acoustic quality by suppressing dispersion of a compound in an alloy when a joint is remelted or when a high temperature load is applied, while achieving higher heat cycle characteristics than before. do. SOLUTION: The solder alloy has Ag: 3.1 to 4.0% by mass, Cu: 0.6 to 0.8% by mass, Bi: 1.5 to 5.5% by mass, Sb: 1.0 to 1. It consists of 6.0% by mass, Co: 0.001 to 0.030% by mass, Fe: 0.02 to 0.05% by mass, and the balance Sn. [Selection diagram] Fig. 1