HEAT DISSIPATION IN MICROELECTRONIC SYSTEMS USING PHASE CHANGE MATERIALS WITH NATURAL CONVECTION

The present study is an initial investigation of the use of phase change materials with natural convection for the dissipation of thermal energy in a model of an integrated circuit (IC) acting as a heat source. A 1.91cm diameter long copper cylinder filled with a phase change material (PCM), P-116 Sunoco wax, was used as the heat exchange structure.

The effectiveness of the PCM cylinder was found to be a strong function of the geometrical arrangement. With the cylinder of PCM positioned on top of the heating cartridge (which simulated the IC heat source), the gravitationally induced natural convection currents are shown to play a significant role in dissipating the heat generated by the cartridge. In an inverted position the effects of natural convection currents were not apparent. The effective thermal conductivity of the cylinder containing the melted wax was at least an order of magnitude higher when positioned above the heating cartridge than when positioned below. Pictures of the melting process were taken for three different experimental configurations, and these substantiate the existence of the natural convection currents in the melt.