Simulation of the Filler Stuck Mechanism in Molding Process and Verification

For the next packaging architecture generation, the epoxy molding compound (EMC) has achieved a high thermal conductivity through higher alumina filler loading to provide better thermal dissipation performance. For this reason, many companies were studied for the feasibility as a filler for EMC and the effects of various experimental parameters on the thermal conductivity and moisture resistance of the EMC were investigated.In this paper, we analyzed the filler influence behavior in molding process, which can predict the buoyant spherical particles flow field between chip and bump. The flow variation of the normal stress and resistance during molding process was considered by using filler flow with stuck effects. However, the presence of balance filler concentration between the resin and the hardener can decrease space for voids.Based on the simulation results, different bump height demonstrated stuck percentage of filler concentration directly, and provided a judgement way to improve encapsulation performance.