Examination of thermal performance of board-level QFP with unattached drop-in heat spreader

We evaluate the board-level thermal performance of QFP with an unattached drop-in heat spreader numerically. The die is given a power and induced thermomechanical deformations and corresponding gap distributions on the unattached interface between the heat spreader and the die pad are calculated through the 3D thermal-mechanical coupling analysis incorporated with contact methodologies. Thermal performances of the package with different interfacial conditions are examined and compared.