Direct Capture of Switching Mechanical Wave on IGBT Bare Dies

Switching mechanical wave (SMW) effect has attracted extensive attention over the past few years owing to its broad application prospects in condition monitoring for insulated gate bipolar transistor (IGBT) devices. Nevertheless, current research focuses on an indirect approach of acoustic emission (AE) detection technology to implement the investigation of such phenomenon, which is not conducive to the mechanism revelation of SMW effect and the accurate extraction of its physical characteristics. Herein, an effective detection method based on laser interferometric vibrometer is developed to directly capture SMW on IGBT bare dies. Combining segmented sliding average filtering and empirical mode decomposition, an efficient extraction algorithm is proposed to realize accurate acquisition of weak SMW signal. Based on this method, the dependency relationship between the SMW signal and turn-off switching parameters of IGBT chips is investigated with an inductive pulse testing circuit, indicating that the intensity of SMW presents significantly positive correlation with the turn-off power dissipation. Moreover, with the aid of electronical scanning platform, field distribution characteristics of SMW are also investigated. This work provides an effective method to realize direct capture of SMW on IGBT bare dies, paving the way to facilitate fundamental exploration of SMW effect in power electronic devices.