Application of thermal network approach to electrical-thermal co-simulation and chip-package-board extraction

Today's electronic products are getting highly integrated. The thermal design can no longer be separated from the electrical design, and the chip, package and PCB (Printed Circuit Board) designs are tightening in the system design process. To address this challenge, the system level electrical-thermal co-design and optimization are of importance. In this paper, two different numerical approaches are presented on the system level electrical-thermal co-simulation of Huawei's computer server. The first one is based on the detailed modeling of chips, package and PCB, and the traditional finite element method (FEM) is used for the co-simulation. It has its accuracy advantage, and can provide detailed assessments of the system's electrical and thermal performances, and also the couplings between them. This approach is demonstrated through an electrical-thermal co-simulation of a merged chip, package and PCB design in the server. The second approach is based on a novel dynamic thermal model which has demonstrated high accuracy and efficiency especially in transient analysis of a complex system, and the fast network simulator is used for the system-level thermal simulation. In this paper, the computer server is decoupled into multiple domains such as air flows, chassis, heat sinks, PCB boards, packages, etc., and the thermal system can be reconstructed as an integrated model-based network. Both steady and transient thermal simulations are presented, and thermal simulation results are validated with the experimental data.