A phase-field model of electrochemical migration for silver-based conductive adhesives

Abstract

Electrochemical migration failure is the main reliability problem that silver conductive adhesives face in the field of power electronics. However, there is no prior existing study that describes the electrochemical migration process of silver conductive adhesive using the phase-field model. In this study, a phase-field model is proposed to study the electrochemical migration process of silver-based conductive adhesive. The model involves the analysis of electrochemical reactions, diffusion of metal ions, applied electrode potential and overpotential and the morphology of electrochemically migrating dendrites. Model-building is based on the water drop (WD) test of silver conductive adhesive. The simulation results of the phase-field model not only reproduce the morphology of the silver dendrite, but also realize the critical voltage phenomenon in the WD experiments. In addition, by comparing the results of WD experiments as well as the model simulations, we demonstrate that the phase-field model is able to predict the electrochemical migration failure time of silver conductive adhesives effectively. The proposed model may be a helpful tool for understanding and predicting the evolution of dendrites during the electrochemical migration of silver-based conductive adhesives.