Void risk prediction for semiconductor packages considering the air venting analysis with fluid/structure interaction method

According as high density packaging options such as multi-die staking or package stacking technologies are developed, the major mold process related quality concerns such as severe air void entrapment under the die. The accurate analysis of venting is important for realistic prediction of voids that may occur during chip encapsulation. This study reports a perspective investigation of computational modeling of air venting analysis with fluid-structure interaction (FSI) during microchip encapsulation process. The venting analysis is to calculate the pressure drop of the air that passes through the vent and include the effects of air pressure on the flow front. Through the integrated method with FSI method, we can predict precisely the FSI behavior with the dynamic mesh deformation technique simultaneously in accordance with venting analysis. This is different from previous study that only one way considered fixed geometry during venting analysis. Furthermore, a series of analyses are conducted to compare the experimental data to study the void risk. This result shows that the proposed modeling methodology is able to obtain better match of the experiment vs. simulation data than a traditional analysis.