Novel Prognostics for IGBTs Using Wire-Bond Contact Degradation Model Considering On-Chip Temperature Distribution
Xinlong Wu, Xin Yang, Junjie Ye, Guoyou Liu
Abstract
Remaining useful lifetime (RUL) prediction for lift-off of bond wires in IGBT modules is essential to avoid strenuous periodic maintenance and electrical accidents of IGBT-based power converters. However, existing model-driven RUL methods mostly focus on lift-off of the first bond wire and rarely consider on-chip temperature distribution, which result in low prediction accuracy. Herein, a novel prognostic method for bond wire lift-off failure in IGBT considers uneven on-chip temperature distribution during crack propagation at the bond-metallization interface (BMI), which fulfills improved prediction error for RUL. In this method, a wire-bond contact degradation model is built according to the on-chip temperature distribution. The number of power cycles as a function of the crack length and temperature swing of BMI is determined by finite element analysis and power cycling test. In this way, the equivalent resistance reflecting crack propagation at BMI can be accurately estimated, and the degradation curve of the <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small>-state voltage (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ce_on</sub>) can be predicted to yield RUL under the widely acknowledged failure criteria of bond wire. The effectiveness and generalization of the proposed method are validated by additional tests and show great superiority to the prior-art condition-based RUL prediction methods.