Numerical Evaluation of Sintered Silver Die Attachments Based on Different Material Parameters and Creep Constitutive Models

Finite element analysis (FEA) is perhaps the most popular technique used for simulating the thermally induced failures of sintered silver die attachments in power electronics. The accuracy of the stress-strain relationship estimations of power electronics is highly influenced by the material mechanical properties and the creep constitutive models used throughout the simulations. Therefore, the current article aims to investigate several Anand-based material properties of the sintered silver bonds considering several mechanical creep constitutive models effect of thermal fatigue life of sintered silver bonds using extensive 3-D FEA thermomechanical simulations. In this investigation, the FEA models are first correlated with the displacement results of the digital image correlation (DIC) experiments. Furthermore, the effect of the material parameters and creep models on the solder stresses, strains, and inelastic strain energy densities and hence on the lifetime predictions of the die attachment layer is discussed in detail. The results showed that the solder behavior is highly dependent on the material parameters as well as creep modeling. Finally, a detailed discussion on the effect of such discrepancies on the predictions and evaluations of sintered silver die attachments fatigue life is also presented.