High temperature resistant Ni-Sn transient liquid phase sintering bonding for new generation semiconductor power electronic devices

This paper presents the microstructural evolution of a Niekel-Tin(Ni-Sn) TLPS process. Ni-Sn power mixture was assembled in a Ni/Ni-Sn/Ni sandwiched structure and sintered in a vacuum furnace using different times at 340°C. The results show that after 180min with slight pressure of 0.1MPa the majority of Sn and Ni in the joint have completely formed intermetallic compounds(IMC) and the jointing layers mainly consists of Ni₃Sn₄, but not dense enough. With the increase of processing time, a dense microstructure can be observed after 300min. Microstructural characterization revealed the formation joints governed by the interdiffusion of the main constituents. The differential scanning calorimetry(DSC) profiles also show that the melting endothermic peak corresponding to Sn is negligible after 180min at 340°C and the melting event corresponding to the Ni₃Sn₄ occurs at approximate 798.9°C. Compared to the traditional solding technique, a higher temperature resistance bonding joint can be achieved using the Ni-Sn TLPS bonding at lower bonding temperature.