Bonding Performance of Pressure Copper Sintering Paste on Different Metalized Substrate/Die

In this work, a pressure copper (Cu) sintering paste, which has been promoted to high power application with high thermal and electrical conductivity, was developed. The sintering of the pressure Cu-paste in a nitrogen atmosphere on different metal surfaces (Cu, silver (Ag), and gold (Au)) was investigated. The pre-dry (temperature and time) and sintering parameters (temperature, pressure, and time) were adjusted to achieve strong joints. Compared to the Ag and Au surfaces of the substrate or dummy die, the highest shear strength over 65MPa was achieved on a Cu surface with the advanced Cu sintering paste. This property breaks the regular procedure of requiring Ag or Au plating for dies or substrates for Ag sintering paste. The sintering conditions for the pressure Cu paste are 250-280°C, 12-25MPa, and 3-10min under a nitrogen atmosphere. After 1,000 cycles of thermo-cycling testing (TCT) at −65°C–150°C, the pressure Cu sintered joints showed stable performance without delamination. Furthermore, this Cu sintering paste can be applied by both printing and dispensing, which are widely used in the electronic industry.