ATSim3D: Towards Accurate Thermal Simulator for Heterogeneous 3D-IC Systems Considering Nonlinear Leakage and Conductivity
Qipan Wang, Tianxiang Zhu, Yibo Lin, Runsheng Wang, Ru Huang
TL;DR
The paper tackles the challenge of accurate, high-resolution thermal simulation for nonlinear and heterogeneous 3D-ICs by introducing ATSim3D, a global-local framework that couples a compact global model with local finite-volume solves and employs Kirchhoff transformation to handle temperature-dependent conductivity. Through iterative updates of leakage and conductivity and parallelized local computations, ATSim3D achieves significant speedups (average around $40\times$) over rigorous solvers like COMSOL while maintaining low errors (relative $<3\%$, max $<3^\circ\mathrm{C}$) at resolutions up to $4096\times4096$. The approach demonstrates strong performance across Mono3D and TSV-based 3D-ICs, delivering a state-of-the-art high-resolution capability and enabling practical thermal-aware design for next-generation 3D integration. Overall, ATSim3D provides a scalable, multi-scale solution that effectively models nonlinear thermal effects in heterogeneous 3D-ICs with substantial efficiency gains.
Abstract
Thermal simulation plays a fundamental role in the thermal design of integrated circuits, especially 3D ICs. Current simulators require significant runtime for high-resolution simulation, and dismiss the complex nonlinear thermal effects, such as nonlinear thermal conductivity and leakage power. To address these issues, we propose ATSim3D, a thermal simulator for simulating the steady-state temperature profile of nonlinear and heterogeneous 3D IC systems. We utilize the global-local approach, combining a compact thermal model at the global level, and a finite volume method at the local level. We tackle the nonlinear effects with Kirchhoff transformation and iteration. ATSim3D enables local-level parallelization that helps achieve an average speedup of 40x compared to COMSOL, with a relative error <3% and a state-of-the-art resolution of 4096 x 4096, holding promise for enhancing thermal-aware design in 3D ICs.
