Influence of Porosity on the Mechanical Properties of Hybrid Silver Sintered Joint

In this study, a type of hybrid Ag sintering paste is selected and characterized. Samples were made under different sintering conditions with rising temperature and duration. Microstructures for hybrid sintered Ag joint were characterized by SEM morphologies. The Ag particles were sintered and necked together during sintering, with the thermal resistant polymers filling in the pores around Ag particles. However, excessive high temperature will lead to oversintering and the residual polymers will decompose which result in an inhomogeneous microstructure. Meanwhile, delamination was found at the plated Ag/Cu interfaces which lead to poor shear strength at 380°C. Shear test and failure modes under different sintering conditions were then studied and analyzed. The shear strength for sintered Ag joint after one-hour sintering was lower than that after two-hours sintering, and adhesive failures were found in part of the fracture surfaces.