Investigation of Bond Wire Lift-Off by Analyzing the Controller Output Voltage Harmonics for the Purpose of Condition Monitoring

This paper presents a new approach in the field of condition monitoring of power semiconductors in power converters. The new approach avoids additional sensors and uses only the data that is already available in a power electronic system. This results in advantages such as saving extra costs and eliminating potential sources of failure. In this paper, the aging mechanism of bond wire lift-off is investigated. First, it is shown by simulations that output voltage harmonics of the current controller contain information about the bond wire lift-off aging mechanism. For testing the new approach in practice, real data are recorded in a test bench for a power module with unharmed bond-wires in order to train an algorithm for normal behavior. Then the aging mechanism bond wire lift-off is induced by cutting off bond wires of a power module with the aim of testing the functionality of the algorithm. The results of this investigation show that the proposed approach is able to detect the anomaly in the data set.