Fast 3-D Thermal Simulation for Integrated Circuits With Domain Decomposition Method

For accurate thermal simulation of integrated circuits (ICs), heat sink components in chip package must be considered. In this letter, techniques based on the domain decomposition method (DDM) are presented for the 3-D thermal simulation of nonrectangular IC thermal model including heat sink and heat spreader. A relaxed nonoverlapping DDM algorithm is employed to convert the problem to subproblems on rectangular subdomains. Then, a nonconformal discretization strategy is proposed to reduce the problem complexity with negligible error. Numerical experiments on several 2-D and 3-D IC test cases demonstrate that the relaxed nonoverlapping DDM is faster than the other preconditioned conjugate gradient algorithms with same mesh grid. The nonconformal discretization achieves further 10x reduction of runtime and memory usage.