Visualization of Fluid/Structure Interaction in IC Encapsulation

This paper presents the visualization of the fluid/structure interaction (FSI) in molded integrated-circuit (IC) packaging. The complexity and high cost of the experimental setup in the molded packaging make the FSI visualization difficult during the encapsulation process, particularly for tiny and thinned chips in IC packages. To address this problem, we fabricated a scaled-up transparent molded package, and the encapsulation process was experimentally performed to visualize the FSI phenomenon. Two scaled-up (single- and stacked-chip) IC packages were considered in the experiment to investigate the FSI, flow front advancement, and void formation. The void formation mechanisms for both imitated IC packages were also studied. Moreover, finite-volume and finite-element codes, via the mesh-based parallel code coupling interface method, were used to describe the physics of FSI during the encapsulation. The predicted flow front advancement, flow profiles, and chip deformation were validated with the experimental results. Hence, this paper is expected to provide a better understanding of the FSI phenomenon during the IC encapsulation.