Failure mechanism and theoretical model of high-temperature tensile creep of sintered nano-silver

The creep properties of sintered nano-silver, which are related to the microstructure evolution, are crucial for the reliability of the packaging structure of wide bandgap semiconductors. In this work, numerical simulations were conducted to investigate the relationship between the creep mechanism and microstructure. Meanwhile, corresponding constitutive models were proposed to describe the creep and damage processes of sintered nano-silver in high-temperature environments. Firstly, a random pore model was developed based on the micro-characteristics of sintered nano-silver to reveal the role of micropores during the creep process. The fracture process of the sintered neck was simulated through molecular dynamics to elucidate the microscopic basis of the creep failure of sintered nano-silver. Then, a damage dissipation potential was proposed based on the thermodynamic framework to describe the damage evolution of sintered nano-silver during the creep process. Finally, a creep model was established to predict accurately the creep and creep rate of tensile creep.