Heat Sinks for Miniature Thermoelectric Coolers: Selection and Characterization

The effect of heat sink (HS) thermal resistance on the performance of a thermoelectric cooler (TEC) has been studied. A method of HS characterization is proposed for the typical case of substantial mismatch in the dimensions of these components. This dimension mismatch causes significant heat spreading resistance in the HS base plate which is highly dependent on the lack of conformity of the components. In this study we investigated modern a HS whose thermal resistance Rd was determined experimentally by use of a dummy heater of fixed dimensions. An analytical method is proposed for predicting HS thermal resistance for arbitrary heater dimensions using the certified Rd value as sole reference point. The method is based on an HS thermal model with three-dimensional heat spread in its base plate. This theoretical approach was used for characterization of HS from Alpha Company, a manufacturer of HS for microelectronics. HS with low pressure drop were considered under conditions of natural and forced convection. It is shown that their thermal resistance, which depends on TEC dimensions, can differ substantially from the certified value.