基于模糊集理论的MCM热分布算法研究

基于模糊集理论,提出了MCM模糊热分布算法。算法中MCM的每个芯片受到芯片间的排斥力、基板边缘对芯片的吸引力及基板中心对芯片的吸引力三种视在作用力。通过模糊推理规则分析了这些力和芯片分布间的模糊关系。高度法解模糊化后,以三力之和最小时的芯片分布作为最佳芯片分布方案。利用有限元法验证了模糊热分布算法的有效性,并将仿真结果与采用四分法得到的结果比较,表明利用该算法得到的MCM热分布比采用四分法得到的热分布更合理、更稳定。

Study of Multi-Chip Module Thermal Placement Algorithm Based on Fuzzy Set Theory

An algorithm based on the fuzzy set theory for the placement of chips on multi-chips modules (MCM) substrate is presented. In this algorithm, any chip in MCM is suffered three apparent forces:the repulsive force between chips, the attractive force between substrate boundaries and chip, and the attractive force between substrate and substrate center. The fuzzy relationships between the forces and the placement of chips are analyzed by the fuzzy inference rules. After defuzzification by the height method, the optimal placement of chips is obtained, in which the resulting apparent force is minimized. Finally, the validity of the algorithm is verified by FEM. Furthermore, the results from the fuzzy thermal placement algorithm are compared with those from the quadrisection placement method. It shows that the chip placement obtained by the fuzzy thermal placement algorithm is more reasonable and robust than that by the quadrisection placement method.