A study on compatibility of thermal interface materials with coolants for data center immersion cooling

In order to address thermal management risk of increasing thermal design power (TDP) for server CPU/GPU in the data centers, liquid cooling has attracted more attention to help address the increasing power for CPU and data center due to its inherent advantage of a higher specific heat (no boiling involved) or latent heat of vaporization (with boiling involved). There have been progresses in the development of single-phase and two-phase immersion cooling, mainly in cooling hardware, however, the material compatibility of the components used on the printed circuit boards (PCB) with the coolants used for immersion cooling remains a major concern before the wide deployment of immersion cooling for the data centers. In this paper, a study is conducted to experimentally investigate compatibility of common thermal interface materials, e.g., grease and phase change material, with typical immersion coolants, like FC-40 for single-phase immersion. The phase change material PTM795X and grease X23-7921-5 are used in this study. This study shall help establish preliminary guidance to TIM's compatibility with coolants used for immersion cooling. Meanwhile, this study helps us down-select TIM materials to future immersion cooling enabling.