Transfer Molding Simulation to Predict Filling Flaws and Optimize Package Design

The process of microchip encapsulation by epoxy resin injection is simulated by employing moldflow modeling. In this work, the use of modeling allows to reproduce the unbalanced flow behavior of the resin within the mold cavity during the filling stage which leads to the formation of voids in the molded package. Simulation results are compared to experimental findings, in which the molding process is interrupted at designed points in time. Comparison shows good agreement between numerical outputs and experimental data and demonstrates the effectiveness of the model. After modeling is validated, the numerical methodology is applied to optimized package design in order to minimize the risk of issues caused by the filling stage. As a result, geometric variations show a significant effect on filling front progression avoiding the generation of structural defects during molding process.