LOW-SILVER-CONTENT SOLDER ALLOY AND SOLDER PASTE COMPOSITION

摘要

This low-silver-content solder alloy comprises 0.05-2.0 mass% of silver, 1.0 mass% or less of copper, 3.0 mass% or less of antimony, 2.0 mass% or less of bismuth, 4.0 mass% or less of indium, 0.2 mass% or less of nickel, 0.1 mass% or less of germanium and 0.5 mass% or less of cobalt (wherein the content of each of the above-mentioned elements copper, antimony, bismuth, indium, nickel, germanium and cobalt is not 0 mass%), with the remainder being tin. According to the present invention, it becomes possible to provide a low-silver-content solder alloy which has a reduced Ag content and therefore can be produced at reduced cost, has excellent stretching properties, an excellent melting point, excellent strength and the like, and also has high fatigue resistance (cold thermal fatigue resistance) and long-lasting reliability.