Realization and thermal analysis of silicon thermal spreaders used in power electronics cooling

Currently the thermal losses of power electronic devices are increasing. At the same time, their sizes are decreasing. Consequently heat sinks have to dissipate very large heat flux densities. Heat pipes are very effective heat transfer devices and can be used to raise the thermal conductive path in order to spread a concentrated heat source over a much larger surface area. As a result, the high heat flux at the heat source can be reduced to a much smaller and manageable level that can be dissipated through conventional cooling methods. At the first part of this paper we present the silicon heat spreader structure. Then an analytical model of heat pipe limits is described and finally an experimental study and test results are presented in order to show the interests of heat pipes in power electronics cooling.