Enhancement of multichip modules (MCMs) cooling by incorporating micro-heat pipes and other high thermal conductivity materials into microchannel heat sinks

Multichip modules (MCMs) have benefited from the use of microchannels for the effective removal of heat. This paper covers an investigation in which micro-heat pipes and other high thermal conductivity materials (such as graphite) have been incorporated in different configurations into MCM microchannel heat sink designs. The addition of micro-heat pipes into a microchannel heat sink system allows for the increase of heat dissipation capabilities without increasing the flow-through (pumping power). Computational studies are described in which the following parameters are changed: fin material, fin height, heat pipe configuration, and pumping power. The numerical simulations were carried out using ICEPAK which is a commercial finite element CFD (computational fluid dynamic) software package by Fluent, Inc. Results indicate that higher heat transfer rates are indeed achieved by incorporating micro heat pipes and other high thermal conductivity materials into microchannel heat sinks. Typical increases in heat transfer out of the systems was found to be roughly of the order of 10-20% over plain microchannels for the same flow rate and pressure.