Numerical and Experimental Investigation of Microchip Encapsulation

A numerical simulation of moving boundaries in a two-dimensional, inertia-free, incompressible flow with shear-thinning viscosity is presented. A controlvolume approach with fixed finite-element mesh is used for predicting the fluid-front advancement. The experimental results for nine different configurations of upperand lower-cavity thickness in a flow domain similar to the mold cavity used for microchip encapsulation are reported. The predicted fluid-front advancement and pressure are found to be in good agreement with the corresponding experimental measurements. The difference in pressure on two sides of the paddle is used to develop an analytical model for predicting the paddle shift during microchip encapsulation.