Securing the reliability of power electronics packaging

The reliability requirements of 100 FIT specified for a power electronics module are so high that they can be checked experimentally only with accelerated tests. A generally applicable concept is thus presented for securing the reliability of the power electronics packaging. It consists of five parts: determining the real stress in operation, examining the physics of failure under real stress conditions, developing built-in reliability measures and standardised accelerated reliability tests, and testing the power electronics module in a real system. The concept is explained on the basis of an IGBT module and its electrical insulation: both partial discharges and dielectric breakdowns are reliability risks which can lead to major disturbances in operation. A lot of conceivable insulating failures are presented with the aid of fishbone diagrams. Changes in the mechanical strength of ceramic substrates during the manufacturing process are used to illustrate the built-in reliability process.