Determination of State-of-Health and Remaining Lifetime of Power Modules

A method for remaining lifetime determination of power modules is presented. The bond shear force of bond wires after certain power cycles was compared to power cycling test results. A difference in remaining lifetime determination of approximately 50 % was found. The work focusses on elaboration of a model of dependency of remaining shear force to the number of power cycles as well as the validity of power cycling tests results for remaining lifetime statements. A further indicator, scanning acoustic microscopy of substrate solder, is investigated to determine the relation between decreasing area of solder connection and remaining lifetime.