Dynamic Modeling Method of Electro-Thermo-Mechanical Degradation in IGBT Modules

Abstract

A degradation model investigating the electrothermo-mechanical fatigue, experienced by insulated gate bipolar transistors modules, is presented. To illustrate the concept, a specific case of power modules subjected to active power cycling which induce failure through bond wire lift-off is considered. Bond wire lift-off is believed to be due to thermally induced stress arising from a mismatch in the coefficients of thermal expansion between the wires and the given substrate. Overall, the theoretical evaluation is based on determining the thermo-mechanical stress around the bond wire/substrate interface through multiphysics-based models. The simulation detail and included equations are specified according to the region of interest and their complexity. In common, however, is the use of the finite element method combined with empirical equations. The final result is a numerical approach to evaluate the damage accumulated by a given load which may be used for prediction of lifetime or optimization of work points and module geometry.

Comparative Study of Al Metallization Degradation in Power Diodes Under Passive and Active Thermal Cycling

“…This means that the device loading increases when the DUT starts degrading. In general, this is considered to be a much harder test than that at constant temperature, while also closer to real operating conditions [1], [2], [4]. The accelerated test is performed with a load current per chip between 75 A − 85 A, a water cooling temperature of 80 • C, and on/off times of 1 s/2.3 s. This set of parameters is chosen to obtain an initial ∆T of approximately 50 • C for non-degraded devices.…”

“…The same type of semiconductor die may experience short and long load cycles with varying amplitude depending on particular operation conditions [1]- [3]. Thermal factors are especially crucial for power electronic devices where the currents can reach tens or hundreds of amperes leading to very significant thermally induced stresses [4]. An example for such case can be high power modules used in wind power generators [5].…”

Nanoseconds Switching Time Monitoring of Insulated Gate Bipolar Transistor Module by Under-Sampling Reconstruction of High-Speed Switching Transitions Signal

“…The IGBT junction temperature is a key parameter to directly reflect the IGBT safety margin, health states and operation performance, but it is difficult to be measured due to the encapsulated structure of the semiconductor device [7]. The existing IGBT junction temperature estimation methods can be mainly classified into a model-based method [8,9] and a thermo-sensitive electrical parameter (TSEP) method [7,10,11]. The model-based methods estimate IGBT junction temperature as the response of an equivalent thermal RC network to power losses, which require a high measurement accuracy of instantaneous power loss [11] and correct identification of the thermal RC network [12].…”

Enabling Junction Temperature Estimation via Collector-Side Thermo-Sensitive Electrical Parameters Through Emitter Stray Inductance in High-Power IGBT Modules

“…Nevertheless, the distances of the formers from the latter ones together with the considerable response delays typically lead to a great estimation error. In order to get a faster estimation of Tj, many efforts have been done very recently on model-based methods [11][12][13][14]. In such methods, Tj estimation can be achieved as the response of an equivalent thermal RC network to power losses.…”