Optimal heat transfer performance of the microfluidic electrospray cooling devices

Future thermal management of microelectronics demands high heat flux removal capabilities due to rapid increases in component and heat flux densities generated from integrated circuits (ICs). Although electrospray evaporative cooling (ESEC) has been investigated as the potential package-level thermal management solution for future microelectronics, the optimal heat transfer performance of ESEC devices using a different number of nozzles has not been thoroughly investigated as a whole. This paper presents three different kinds of ESEC chambers with different spacing, in order to investigate their optimal heat transfer performances. The maximum enhancement ratio of 1.87 was achieved by the 8-nozzle 5 mm spacing ESEC chamber at the lowest heat flux. The optimal heat transfer performance for the 4-nozzle chamber is the chamber with 6 mm spacing. Both the 8-nozzle 5 mm spacing ESEC chamber and the 8-nozzle 6 mm spacing ESEC chamber achieve optimal heat transfer performance. Furthermore, although the increase in the number of electrospray nozzles of the ESEC chambers does not provide obvious improvement on the maximum achievable heat transfer enhancement ratio, the highest cooling rate is noticeably enhanced by increasing the number of electrospray nozzles of the ESEC chamber.