Two-Phase Immersion Cooling of Simulated Server Chips Using HFE-7100

Two-phase immersion cooling are favored for high performance servers with high-power chips. This paper reports the results of boiling experiments of dual-chip and single-chip using HFE7100 at the subcooling of 10, 20 and 30 K. The boiling curves and total heat transfer coefficient obtained from dual-chip and single-chip boiling experiments, at different subcooling, are compared. Results show that the heat dissipation ability of top chip is comparable to that of bottom chip, and the gap increases with the heat flux. But the subcooling of liquid has little effect on the maximum gap. As for the subcooling boiling, the maximum heat flux differences $\Delta {q^{''}}_{{\text{s}}\max }$ are 7 W/cm
²
to 7.2 W/cm
²
and, and the maximum superheat differences ΔT
smax
are 3.7 K to 5.9 K. In control experiments at subcooling of 30 K, the heat flux of top chip in dual-chip is always higher than that of top chip in single-chip, and the maximum improvement is about 1 W/cm
²
. For the subcooling of 10 and 20 K, the heat flux of top chip in dual-chip is higher than that of top chip in single-chip at low heat flux (< 11 W/cm
²
), but it is lower than that of top chip in single-chip. Therefore, in the design of vertical arranged dual-chip or multi-chip servers, the differences and interactions in heat dissipation performance of top and bottom chips should be considered, and the appropriate control strategies should be adopted.