Mechanical properties of porous silver materials depending on sintering parameters

We investigated the mechanical properties of a silver sinter paste dependent on sintering and drying conditions. For these experiments we fabricated dedicated samples without silicon and leadframe to investigate the pure material properties. Our investigation on the influence of drying and sintering conditions demonstrated that the longer the sintering time and the higher the temperature the higher is the stiffness of the sintered layer. We found that a sintering pressure in the range of 2, 5-10 MPa has no influence on the sintered layer for the investigated paste. An optimum drying temperature of 150°C was identified. Microstructure evaluation showed that the concentration of the pores was about 19% ±3%. We observe that the sintering conditions only influence the pores size but not the pores area/volume. These material studies allow us to achieve material parameter inputs for further simulations to describe the die attach process. In addition we achieve the optimum material parameter for the sintering process.