Using of bond-wire resistance as aging indicator of semiconductor power modules

This paper investigates the use of wire—bonds contact resistance as indicator to diagnose the health state of power electronics modules. This technique is especially dedicated to monitoring the degradation of the topside interconnection (metallization-wire bonds) when the module is wired with a Kelvin point. One advantage of this indicator is that it can be followed online, without being disturbed by current or voltage, to diagnose the state of health and, possibly, the prognosis of the remaining lifetime of the power module by associating it with a lifetime model. For this purpose, based on power-cycling tests in different conditions, a comparison between this indicator and the one commonly used, i.e. the collector-emitter voltage Vce, shows that the first one is much more sensitive to the degradations, easier to use online and finally should be more suitable for lifetime prognosis.