Improving Monitoring of Parallel Ageing of IGBT Bond-Wires and Solder Layers by Temperature Compensation

Conference: PCIM Europe digital days 2021 - International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management
05/03/2021 - 05/07/2021 at Online

Proceedings: PCIM Europe digital days 2021

Pages: 7Language: englishTyp: PDF

Hernes, Magnar; D'Arco, Salvatore; Spro, Ole Christian (SINTEF Energy Research, Norway)
Peftitsis, Dimosthenis (Norwegian University of Science and Technology NTNU, Norway)

Two failure mechanisms can generally be identified by means of accelerated power cycling tests on IGBT power modules: bond-wire lift-off and die-solder delamination. Aging associated to bond-wire lift-off is detected by monitoring the increase of collector-emitter voltage while aging linked to die-solder delamination is detected by observing the increase of thermal resistance. This paper presents experimental results demonstrating the possible effect on the bond-wire end-of-life detection due to concurrent ageing of the solder layer. Solder layer degradation leads to a larger thermal impedance, and consequently, the voltage drop of the IGBT chip increases due to the increased operating temperature. This temperature-driven increase might falsely be interpreted as bond-wire degradation and end-of-life could be stated prematurely. This paper introduces a graphical representation of the power cycling results that gives an overview of the parameter development throughout the test. Based on this representation, the paper proposes a method for temperature compensation that can improve monitoring of bond-wire degradation in the case of parallel aging. Finally, the feasibility and usability of this method is demonstrated.