Warpage of transfer-molded automotive power modules – experimental characterization, numerical simulation and optimization

Warpage behaviour of a transfer-molded power module package has been studied experimentally and numerically throughout the assembly flow. Warpage in different assembly states ((1) bare metal-ceramic substrates, (2) substrates attached to copper leadframe, (3) transfer-molded package) has been assessed and influences of variations of substrate backside structure and epoxy mold compound type onto the warpage evaluated. The numerical modeling framework build-up has been validated within this study and does allow for rapid warpage prediction based on package geometry and manufacturing process temperatures.