Research on Physics-of-Failure Lifetime of Bond Wires in SiC Power Modules

A physics-based lifetime prediction model for bond wire degradation in SiC power modules is presented, explicitly accounting for spatial variations in crack growth rate due to significant temperature gradients across the chip. The methodology integrates the Paris law-based modeling of crack propagation as a function of bond-wire temperature and power cycles. On-state voltage inference from crack length via an on-state resistance model, enabling simultaneous prediction of end-of-life and remaining useful lifetime. Bond-wire and substrate temperatures extracted via multiphysics simulation were validated, and dye-penetrant crack experiments were done to validate the necessity of accounting for variations in crack growth rates of all different bonding wires. The model demonstrates a high accuracy in predicting bond-wire failure under multiple operating conditions, outperforming conventional lifetime methods. This approach provides manufacturers with a tool for design optimization and users with prognostic capability for predictive maintenance of SiC power modules.