Electrothermal–Mechanical Multiphysics Co-Simulation of Chiplet Architecture Based on the FDTD Method

In this paper, we introduce a novel electro-thermo-mechanical simulation framework utilizing the unified FDTD method for efficient and accurate analysis of electrical, thermal, stress, and displacement responses in chiplet architectures. To enable precise stress simulation in heterogeneous system such as redistribution layers (RDL) structures, we developed equilibrium differential equations for multi-material systems and derived finite difference equations for displacement equilibrium using central differencing, including formulations for free boundary conditions. Numerical simulations demonstrate the framework’s effectiveness through thermo-mechanical coupled analyses of block models and simplified RDL structures. Compared with COMSOL commercial software, our FDTD based solver achieves computational errors within 2% for block models and 5% for RDL structures, while demonstrating superior simulation efficiency and significantly reduced memory consumption. The proposed framework offers substantial advantages in modeling complex chiplet based heterogeneous integration systems under strong electromagnetic interference. It effectively characterizes spatiotemporal distributions of electromagnetic fields, temperature fields, mechanical stress, and displacement, providing essential insights for evaluating electromagnetic compatibility (EMC) and signal integrity (SI) in chiplet integration systems.