Enhancement of Saturation Boiling of PF-5060 on Microporous Copper Dendrite Surfaces

Experiments are performed to investigate saturation boiling of degassed PF-5060 dielectric liquid on microporous copper dendrite surface layers deposited on 10x10 mm(2) Cu substrates. The electrochemically deposited surface layers are of different thicknesses (145.6 mu m, 46.3 mu m, and 33.1 mu m). The thickest layer gives the best results: the saturation CHF of 25.27 W/cm(2) occurs at a surface superheat of only 2.9 K and the maximum nucleate boiling heat transfer coefficient, h(MNB), near the end of the fully developed nucleate boiling region, is 8.76 W/cm(2) K. In addition, nucleate boiling ensues at a surface temperature slightly above saturation (< 0.5 K), with no temperature excursion. The temperature excursions before initiating boiling on the 46.3 mu m and 33.1 mu m thick Cu nanodendrite surface layers are small (3.7 K and 6 K), corresponding to surface temperatures of similar to 55.1 degrees C and 57.4 degrees C, respectively. These temperatures are much lower than recommended (85 degrees C) for reliable operation of most silicon electronics and central processor units. [DOI: 10.1115/1.4000975]