A NEW LOW-GWP DIELECTRIC FLUID FOR TWO- PHASE IMMERSION COOLING

Two-phase immersion cooling (2-PIC) is one the most promising technologies for thermal management of next generation servers and chips. 2-PIC can help data centers dramatically reduce energy and water usage, physical footprint while providing much higher heat rejection rates for chips versus air cooling. Given that many commercial two-phase immersion fluids have limitations of either high GWP, poor dielectric properties or challenges such as chemical stability, a new dielectric fluid candidate (DF- 50) is proposed in this paper. Experimental results showed that the dielectric constant and dissipation factor of DF-50 are only about 1.75 and 1x10(-3), respectively, under frequencies up to 67GHz. A signal integrity analysis of cable and microstrip traces showed that the insertion losses of these components when immersed in DF-50 are almost identical to those in air. The actual thermal performance of multiple GPUs equipped with boiler plates and immersed in DF-50 is also investigated. The total thermal resistance based on the average GPU temperature was estimated to be about 0.04 degrees C/W, with further opportunities for improvement.