The application of Cu-Ag submicron composite particles in microelectronic bonding

In this study, Cu-Ag composite pastes with the mixture of Cu@Ag core-shell particles and Ag nanoparticles prepared by one-step spray pyrolysis are developed for microelectronic bonding applications. Cu to Cu bonding can be successfully achieved by thermal compression with the Cu/Ag pastes at 250°C. The joint strength reaches 28.2 MPa and 32.4MPa respectively when bonding pressure holds at 5 MPa and 10MPa at 275°C. It has been demonstrated the joints thus formed remain robust at elevated temperatures up to 250°C and excellent reliability subjected to thermal cycling ranged from -65 °C~150 °C.