Failure criteria for long term Accelerated Power Cycling Test linked to electrical turn off SOA on IGBT module. A 4000 hours test on 1200A-3300V module with AlSiC base plate.

With AlSiC base plate technology for big module, the reliability about thermal cycling due to railway traction is largely improved and the accelerated Power Cycling Test time is increased a lot to reach over 6 months. Then it appears that these failure indicators as; Rth increasing, Vce increasing, or Iges increasing, must be linked to the interface behavior (thermal and mechanical) and the full electrical capabilities of the device to switch on and switch off current and voltage in a converter. This paper discuss about test methodology and protocol of accelerated Pourer Cycling Test (PCT), including turn off Safe Operating Area (SOA) measurement before and after reliability tests in order to evaluate the influence of the parameters drift Vee, Rth, and gate leakage Iges. Mainly, PCT and SOA results are presented on 1200A-3300V IGBT module with AlSiC base plate materials after a 4000 hours test (376000 cycles) on very hard conditions. It is also shown the SOA capability on one IGBT module with gate leakage failure. (C) 2000 Elsevier Science Ltd. All rights reserved.