Optimized heat transfer for high power electronic cooling using arrays of microjets

Electronic cooling has become a subject of interest in recent years due to the rapidly decreasing size of microchips while increasing the amount of heat flux that they must dissipate. Conventional forced air cooling techniques cannot satisfy the cooling requirements and new methods have to be sought. Jet cooling has been used in other industrial fields and has demonstrated the capability of sustaining high heat transfer rates. In this work the heat transfer under arrays of microjets is investigated. Ten different arrays have been tested using deionized water and FC40 as test fluids. The jet diameters employed ranged between 69 and 250 mu m and the jet Reynolds number varied from 73 to 3813. A maximum surface heat flux of 3 10 W/cm(2) was achieved using water jets of 173.6 mu m diameter and 3 mm spacing, impinging at 12.5 m/s on a circular 19.3 mm diameter copper surface. The impinging water temperature was 23.1 degrees C and the surface temperature was 73.9 degrees C. The heat transfer results, consistent with those reported in the literature, have been correlated using only three independent dimensionless parameters. With the use of the correlation developed, an optimal configuration of the main geometrical parameters can be established once the cooling requirements of the electronic component are specified.