Flexible Thermal Conductance Model (TCM) for Efficient Thermal Simulation of 3-D ICs and Packages

Thermal management plays an increasingly important role in the design of 3-D integrated circuits (ICs) and packages. To deal with the related thermal issues, efficient and accurate evaluation of the thermal performance is obviously essential. In this paper, an efficient approach with the flexible thermal conductance model (TCM) is presented for thermal simulation of 3-D ICs and packages. Firstly, the entire structure is partitioned and classified into two kinds of regions, named region of interest (ROI) and region of fixity (ROF). The ROI usually contains the key components in thermal designs while the ROF holds invariant thermal characteristics. Then, in order to represent the thermal impact of ROF on ROI, a novel technique based on the TCM is developed, which can be treated as the equivalent boundary condition of the ROI. By this means, the solution domain of the whole system is constrained to the ROI, which results in significant reduction of computational costs. Furthermore, in the representation of ROF, a flexible TCM with elegant rational expressions on the heat convection coefficient is proposed to deal with varying boundary conditions, which greatly expands the applicability of this method. The validity and efficiency of the proposed method is illustrated by the numerical examples, where a 138x speedup is achieved comparing with the commercial software.