Thermal Systems

Today's leading edge electronics are pushing the limits of traditional cooling technologies. The demand for higher performance in ever-smaller packages has driven component heat fluxes beyond the capabilities of air-cooled heat sinks and, in an increasing number of applications, even beyond the capabilities of conventional liquid-cooled cold plates. How can manufacturers maintain desired temperatures and ensure the reliability of their systems in the face of ever increasing heat fluxes?

Conventional liquid-cooled cold plates take advantage of the higher heat removal capacity of liquids (compared to air), but still cannot reach the low thermal resistances required by the most demanding applications. To meet performance requirements, present systems must incorporate large heat spreaders and, in extreme situations, may even resort to active refrigeration.

The only way to substantially reduce thermal resistance of cold plates is to shorten the conduction distance through the heat sink walls and into the fluid. In particular, the size of the channels must be decreased by an order of magnitude or more to compensate for the low thermal conductivities of most fluids. Hence, the need for micro-channel cold plates to meet the challenges of extreme heat flux applications.

Prior micro-channel cold plates achieved low thermal resistance, but their high pressure drop and low effectiveness made them unattractive. Moreover, the temperature rise of the fluid resulted in increased thermal resistance along the length of the micro-channels.