基于键合线压降的IGBT模块内部缺陷监测研究

Research on Condition Monitoring for Defects Inside IGBT Modules Based on Voltage Drop of Bond Wires

为了准确地评估出IGBT模块的健康水平,及时发现并更换存在缺陷的IGBT模块,提高功率变流器的可靠性,提出了一种基于键合线压降的IGBT模块内部缺陷诊断方法。通过监测IGBT模块内部单个芯片等效键合线压降的变化,辨识出IGBT模块内键合线的老化状态,进而判断出IGBT模块的健康水平。实验结果表明,基于键合线压降的IGBT模块内部缺陷诊断方法能准确地辨识出模块内键合线的老化过程,与采用监测门极信号辨识模块老化状态的方法相比,所提方法不仅能辨识出单个芯片全部键合线脱落的情况,而且能辨识出部分键合线老化的情况,在辨识精度上有了很大的提高。该方法为确定合适的时机对变流器进行维护、降低系统的维护成本提供了理论依据。

In order to accurately evaluate the health level of insulated gate bipolar transistor （ IGBT）,detect and replace the defective IGBT modules timely, and improve the reliability of power converter, a novel prognostic method for defects inside IGBT module based on the voltage drop of bond wires is presented in this paper with principle and characteristic. The ageing state of bond wires inside IGBT module is diagnosed by the changes of equivalent voltage drop of bond wires on a single chip, and then judge the health level of IGBT module. Experiment result shows that condition monitoring for defects inside IGBT modules based on voltage drop of bond wires can accurately identify the ageing process of bond wires. This method not only diagnoses the defect that all bond wires liftoff on one chip, but also recognizes the condition that part of bond wires liftoff on one chip. It has been greatly improved in terms of accuracy compared with the condition monitoring method by the use of gate signal. This method provides a theoretical support for the maintenance of power converter and can reduce the system maintenance costs.