This paper studies the overload turnoff failure in the insulated-gate bipolar transistor (IGBT) devices of power multichip modules for railway traction. After a detailed experimental analysis carried out through a dedicated test circuit, electrothermal simulations at device level are also presented. The simulation strategy has consisted in inducing a current and temperature mismatch in two IGBT cells. Results show that mismatches in the electrothermal properties of the IGBT device during transient operation can lead to uneven power dissipation, significantly enhancing the risk of failure and reducing the lifetime of the power module. Concretely, simulations qualitatively demonstrate that localized hot-spot formation due to a dynamic breakdown could lead to a second breakdown mechanism.

This work was supported in part by the European Project ‘Power Reliability for Traction Electronics’ (PORTES) under Contract MTKI-CT- 2004-517224, by Alstom Transport Tarbes, by the Spanish Ministry of Science and Innovation through Research Programs THERMOS TEC2008-05577 and RUE CSD2009-00046, and by the Consejo Superior de Investigaciones Científicas under Contract “Junta para la Ampliación de Estudios,” JAE-Doc.

9 páginas, 11 figuras.

Peer reviewed