Transient liquid phase Ag-based solder technology for high-temperature packaging applications

A lead-free Ag-based soldering technique through transient-liquid-phase (TLP) bonding is proposed in this study for high-temperature microelectronic packaging applications. The solder paste, which contained Ag and Sn powders with a no-clean flux, was used to join Cu substrates. The setup was bonded at 250 °C for 10 minutes. The study focuses on mechanical and microstructural characterizations of the joints. The shear strength measured at 250 °C shows good high temperature performance of the joint. The effects of Ag and Sn contents on mechanical, electrical and thermal properties of sintered bulk Ag-Sn samples were also investigated independently. The results demonstrate that the Ag-Sn TLP bonding is an effective interconnection method for harsh environment electronic packaging.