Using fluidic simulation for parameter optimization in compression molding of microelectronic packages

Compression molding with liquid encapsulants is a crucial process in microelectronic packaging. Material properties of highly filled systems of reactive epoxy molding compounds (EMC) depend on process conditions in a complex manner, such as shear-thinning behavior superimposed by a time- and temperature-dependent conversion rate, both strongly affecting viscosity. The focus of the present work is set on forces exerted on individual dies during encapsulation in Fan-Out Wafer Level Packaging (FOWLP). The presented framework consists of an analytical approach to estimate the meltfront velocity and simulations carried out to capture the nonlinear kinematics. It offers separate evaluation of pressure and shear-contributions and allows to determine process parameters, such as compression speed and process temperature, to choose encapsulants and thermal-release tapes (TRT) to minimize flying dies.