Reliability-oriented environmental thermal stress analysis of fuses in power electronics

This paper investigates the thermo-mechanical stress experienced by axial lead fuses used in power electronics. Based on some experience, the approach used in this paper is pure thermal cycling, and the found failure mechanisms have been investigated through X-ray imaging. A two-step analysis, i.e. microscopic inspection and FEM thermo-mechanical simulation have been carried out based on the real geometry, including core and isolation materials, as well as the arc quenching one, which is typically quartz sand. The failure mechanism hypothesis of higher temperature variation at the end hole of the fuse element has been confirmed thanks to the analysis performed. Finally, the fatigue analysis is presented obtained by FEM-based fatigue tool.