A Novel Online Chip-Related Aging Monitoring Method for IGBTs Based on the Leakage Current

Online aging monitoring is the basis for high reliability operation of Insulated gate bipolar transistors (IGBTs). Most monitoring methods focus on the package-related aging. Leakage current (Ileak) has been proposed as a potential chip-related aging (CRA) indicator for IGBTs. However, this method has not been implemented online due to the difficulty in accurate online leakage current measurement. An effective online CRA monitoring method is still required for IGBTs. A novel online CRA monitoring method based on Ileak for IGBTs is proposed in this article. First, an online Ileak measurement circuit is proposed. Second, based on this circuit, an aging monitoring strategy is presented. Finally, accelerating aging tests validate the effectiveness of the proposed method. The on-state voltage drop is selected as an aging indicator for comparison. The proposed method has three advantages. The online CRA monitoring is achieved. It can be used in slight aging situation with high sensitivity because Ileak is linear to the CRA levels. The measurement circuit required by this method is simple and low-cost.