RESEARCH ABOUT NEW LEAD-FREE ALLOY APPLICATION CHARACTER

摘要

There are many types of lead-free alloy, but none of them can be better than SnPb, and also there is no test standard for lead free alloys. Though SAC with 3-4% silver has become the mainstream, drop test reliability is worse and cost is high. In recent years, research about low silver SAC and doped SnCu alloys are much more than before. These alloys are expected to be the trend in the future. In this paper, we investigate the melting temperature range, wetting characteristics, copper dissolution, dross formation, microstructure of several potential alloys, including SAC0307, SAC0807, SnCuNi, comparing with SAC305. These alloys are the most promising wave soldering alloy in replacing SAC305. Through this research, we hope to find a better lead free alloy for high-reliability products.These experiments indicate that SAC0807 have better wetting performance, low dross formation rate and low Cu dissolution rate than other alloys.