Accelerated Qualification of Highly Reliable Chip Interconnect Technology by Power Cycling Under Thermal Overload

Highly reliable interconnects of an IGBT have been tested by power cycling. The test has been successfully accelerated by exceeding the specified operating conditions of the device. The approach is suitable to reduce the test time from several months to one day without changing the underlying failure mechanism, as revealed by experimental results and failure analysis. Additionally, a lifetime model is derived and compared to yet published models, revealing that the lifetime of modern power modules is much less affected by high temperatures, in particular when advanced interconnect technologies like silver-sintering are applied. Limitations and application examples are discussed as well.