Thermal analysis for indirect liquid cooled multichip module using computational fluid dynamic simulation and response surface methodology

This paper demonstrates the application of computational fluid dynamic (CFD) simulation and response surface methodology (RSM) in analyzing the thermal performance of a high input/outputs, seven chips, indirect liquid cooled multichip module which will be applied in a kind of supercomputer. A series of similar experiments and corresponding CFD simulations are conducted firstly to evaluate the validity of CFD simulation method and determine the interfacial thermal resistance of thermal grease iteratively, and then a three-dimensional CFD model is established to investigate the heat transfer and fluid flow of the multichip module. Based on the CFD model, the individual effects of factors such as thermal conductivity of the thermal interface material and thermal grease, thickness of the chips, space between chips, solder bump patterns, solder ball patterns, flow velocity and liquid inlet temperature on the thermal performance of the module are studied with one-factor-at-a-time experimentation, and after that, four significant factors are selected to establish a response surface model of the maximum temperature of the module with central composite design based RSM and analysis of variance.