ATSim3D: Towards Accurate Thermal Simulator for Heterogeneous 3D-IC Systems Considering Nonlinear Leakage and Conductivity

TL;DR

This paper introduces ATSim3D, a high-resolution thermal simulator for 3D integrated circuits that accurately models nonlinear effects and achieves significant speedup over existing tools, aiding thermal-aware design.

Contribution

We develop ATSim3D, a novel thermal simulation approach combining global-local modeling and nonlinear effect handling, with parallelization for high resolution and speed.

Findings

Achieves 40x speedup over COMSOL

Maintains <3% relative error at 4096x4096 resolution

Effectively models nonlinear thermal effects in 3D ICs

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.