Cycle thermal simulation of nano silver paste based on Anand model

Abstract

Since the advantages of low temperature sintering of nano-silver paste, nano silver can sintering at low temperature and work at high temperatures, compared with other lead-free solders, low temperature sintering of nano-silver paste has been applied in various chip packages. In this paper, Anand viscoelastic constitutive model was adopted, and WORKBENCH software was used to simulate the hot cycle load of the array chip of nano-silver paste. The simulation results show that the after four cycles of thermal cycle load, the temperature distribution of the solder joints gradually increases from the center to the surroundings, and the solder joints at the corners have the highest temperature, so the maximum plastic strain accumulation occurred at corner solder joints. For a single solder joint, the temperature near the substrate is higher, so deformation and destroy more prone occurred at the bottom of the solder joints, which is the main two reason that may cause the failure of chip connection.