Quasi-3D Thermal Simulation of Integrated Circuit Systems in Packages
The problem of thermal modeling of modern three-dimensional (3D) integrated circuit (IC) systems in packages (SiPs) is discussed. An effective quasi-3D (Q3D) approach of thermal design is proposed taking into account the specific character of 3D IC stacked multilayer constructions. The fully-3D heat transfer equation for global multilayer construction is reduced to the set of coupled two-dimensional (2D) equations for separate construction layers. As a result, computational difficulties, processor time, and RAM volume are significantly reduced, while accuracy can be provided. A software tool, Overheat-3D-IC, was developed on the base of the generalized Q3D package numerical model. For the first time, the global 3D thermal performances across the modern integrated circuit/through-silicon via/ball grid array (IC-TSV-BGA) and multi-chip (MC)-embedded printed circuit board (PCB) packages were simulated. A ten times decrease of central processing unit (CPU) time was achieved as compared with the 3D solutions obtained by commercial universal 3D simulators, while saving the sufficient accuracy. The simulation error of maximal temperature TMAX determination for different types of packages was not more than 10–20%.