Influence of Testing Parameters on the Failure Mechanism of Power Modules during Active Power Cycling Test

Inhalt:
During active power cycling test (APCT) power modules are actively heated by a cyclic DC load current to achieve a periodic junction temperature swing (DeltaTvj). For the calculation of lifetime models DeltaTvj is the most common parameter. Apart from the temperature swing there are further parameters which deserve closer attention regarding their influence on the lifetime and failure mechanisms. After an increase of + 5 % VCE the modules are considered as failed per definition and then continued to be cycled until an increase of + 20 % of the thermal resistance Rth. After that metallographic cross sections are performed to examine the occurring failure mechanism.