Abstract
In order to evaluate the fatigue life of Sn-3.5Ag solder, which is the candidate base alloy of the lead free solder, fatigue tests were carried out using smooth specimens at 313K. The strain wave forms were (1) fast-tension and fast-compression, (2) slow-tension and slow-compression, and (3) slow-tension and fast-compression. The strain rate of fast straining was 0.1%/sec and that of slow straining was 0.01%/sec. As a result, the fatigue lives (the number of cycles to the crack initiation) were about 3 times as those of the 63Sn-37Pb solder for the fastfast strain wave and the slow-slow strain wave. On the one hand, the fatigue lives of the slowfast strain wave became the about 1/5 of the symmetrical strain wave.
