Modeling Temperature Cycle Fatigue Life of Select SAC Solders

While the presence of silver in SAC solder provided excellent temperature cycling durability, the silver in high silver SAC alloy also made the solders susceptible to failures under drop/shock loading. To improve the drop/shock reliability, the silver content in SAC alloys was reduced from three percent, to as low as no silver. Solder dopants, also known as microalloy additions, are elements (typically 0.1% or lower) other than the main constituents of the alloy that have been shown to improve solder performance. Commonly used microalloy additions include nickel (Ni), bismuth (Bi), manganese (Mn), and antimony (Sb)....