Effects of radiation on enhanced electronic cooling

The radiation component of heat loss and the effect of heat sink orientation on the radiant interchange of heat between electronic components were investigated. The point at which the influence of forced convection cooling overrides the radiation losses was determined. It was assumed that the heat sink resides within a system environment and is used to cool a typical electronic component. The evaluation encompasses the natural convection cooling regime in both the thermally optimum vertical orientation as well as a horizontally mounted orientation. For both cases, the heat sink was evaluated with two surface coatings to determine the effect of the radiant heat loss. The experimental work was then extended to the forced-convection region to determine where the convective coefficient became dominant. A theoretical model was developed that is capable of predicting the radiation effects of high emissive heat sinks based on experimentally determined relationships of standard heat-sink material. It is concluded that the dissipation of heat by radiation could be substantial portion of the total power-dissipation capability