Cu/Sn SLID wafer-level bonding optimization

The objective of this study is to optimize the Cu/Sn solid liquid bonding process, which is an attractive technique for wafer-level MEMS packaging and encapsulation. In order to optimize the bonding process, the effect of bonding temperature profile, initial Sn layer thickness and bond pressure are investigated and discussed. Bond performance is characterized by sealing yield, dicing yield and cross section analysis of the bond interface. With correct design of Cu/Sn layer thickness and temperature profile, high bond yield at bond temperature 270°C and 250°C was obtained.