A novel method to predict fluid/structure interaction in IC packaging

Abstract

This paper reports a perspective investigation of computational modeling of fluid-structure interaction (FSI) in molded integrated-circuit(IC) packaging. The investigation is carried out through two aspects, respectively on interaction between the fluid and structure in the encapsulation process and appropriate methodology for modeling. We present a novel and integrated method to predict the FSI during the encapsulation process. This method not only provides more accurate melt front and pressure result but also predict precisely the FSI behavior through the dynamic mesh deformation technique simultaneously in accordance with continually deformed geometry (two way FSI). This is different from previous study that only one way considered fixed geometry (one way FSI) during encapsulation. Moreover, the experimental data for single- and stacked-chip were compared with the simulation results for two way FSI implementation to verify flow front advancement. From a real paddle shift case study, the result indicates that the deflection prediction is well predicted and could predict void formation well when it considers two way FSI effect. It is expected that this paper could clarify relevant issues in prediction of FSI in IC packaging and induce more considerations for modeling FSI using two way FSI multiphase flow method.