Simulation and Experimental Analysis of Capillary Underfill in 2.5d Multi-Chip Modules

This paper introduces a hybrid numerical method for simulating capillary underfill (CUF) flow in 2.5D multi-chip modules (MCMs). Traditional underfill flow analysis, which relies on extensive experiments, is time-consuming and resource intensive. To address these challenges, we propose a Hybrid Equivalent Bump Group (EBG) model that combines reduced-order modeling of micro bump effects with full 3D Navier-Stokes calculations in the overflow region. This approach significantly reduces computational demands while maintaining high accuracy. Validation against experimental data demonstrates the model's reliability in capturing underfill flow dynamics. The hybrid EBG CUF solver closely matches experimental results, confirming its suitability for large-scale MCM simulations. This research provides an efficient and precise solution for underfill flow simulations, advancing semiconductor packaging technologies.