In the Sn–9Zn–xAg (x ranges from 0.5 to 3.0%) solder system, the Ag–Zn intermetallics start crystallizing as β–AgZn at about 300 °C. Subsequently, the solder experiences two peritectic transformations upon solidification. This results in the multiphase structural feature. The complicated crystallization process can be briefly described as L(liquid) → L + AgZn → L + AgZn + Ag5Zn8 → AgZn + Ag5Zn8 + AgZn3.