Compression Molding Flow Behavior and Void Optimization of an Integrated Circuit Package with Shielding-Metal-Frame.

Abstract

As the demand for smaller and more multifunctional integrated circuit (IC) products increases, system-in-package (SiP) has emerged as a key trend in IC encapsulation. However, the use of polymer-based materials such as epoxy molding compounds (EMCs) introduces complex flow behaviors during the encapsulation process, often leading to void formation, especially in highly integrated SiP structures. This study employs the Moldex3D 2024 R3 simulation software to perform mold-filling analyses of SiP packages using EMC as the encapsulant. The objective is to investigate why voids are consistently observed in the leftmost column of the strip and to determine how to reduce the void size using the Taguchi optimization method. To replicate the actual vacuum-assisted molding conditions, a 1/5 strip model with venting was established. Results show that the flow dynamics of the polymeric encapsulant are significantly affected by shielding frame geometry. Among various design modifications, adding an additional column of shielding metal frame on the left side of the strip most effectively reduces void formation. This research highlights the importance of polymer flow behavior in void prediction and optimization for advanced SiP packaging, providing practical guidelines for material-driven design improvements in IC encapsulation processes.