Improved Anand model considering the influence of sintering process on the packaging interconnection of power modules

Firstly, this investigation designs five distinct sintering processes for sintered silver interconnect materials and prepares interconnect specimens separately. Then, the evolution of microstructure characteristics of the material with sintering process was observed using TEM and SEM. It can be found that as the sintering temperature and time increase, the porosity decreases, while the grain size increases. Secondly, static and cyclic shear tests were performed on sintered silver interconnect specimens at ambient temperature and elevated temperature on an electromagnetic fatigue testing machine equipped with non-contact strain measurement and control technology to examine the impact of sintering process on the mechanical behavior of packaging interconnect materials. Research has shown that as the sintering temperature and time increase, the shear strength increases, while the shear strain amplitude response decreases. Thirdly, this article proposes a viscoplastic constitutive model, which can consider the impact of sintering process, based on the classic Anand model. The influence factor of sintering process is proposed to modify the evolution equation of averaged isotropic resistance to consider the changes in material mechanical properties caused by different sintering processes. Finally, the proposed method was validated using shear stress-strain response data under different processes, and satisfactory simulation results were achieved. This method can be applied to the life prediction of power modules for sintered silver interconnect failure and simulate the warpage caused by sintering.