Thermal design for high-speed, high-density multi-chip module

Examines the boundary conditions of models for finite element analysis of the thermal design of high-speed, high-density multi-chip modules, principally the thermal via and heat sink, and investigates means of improving the accuracy of heat transfer analysis simulation. It is concluded that, in evaluating the effectiveness of thermal vias in heat loss, simulation can yield results close to observed values by considering the substrate a compound material with a uniform thermal and conductivity coefficient determined by the ratio of thermal via cross section area to substrate area. A thermal via area ratio of 10% is satisfactory both from the standpoint of manufacturing and for effectiveness in decreasing thermal resistance. Also, in the model considered the heat transfer coefficient of the heat sink can be determined by using their speeds and comparison with observed results