Innovative Two-Phase Immersion Cooling Solutions for high-power Advanced Packages

This study attempts to study the two-phase immersion cooling for the FOCoS HPC package subject to a power input of up to 1000 W which hasn't been reached before. It explores two approaches: an enhanced boiler surface integrated with the HPC package and a heat pipe heat spreader integrated heat sink. Two-phase immersion cooling is an effective method to meet the exponentially increasing demands of thermal loading of high-density electronic devices. At high chip thermal densities, effective heat spreading along with heat dissipation is paramount to avoid overheating. The current study utilizes a heat pipe spreader integrated with the heat sink, which ensures that the heat properly spreads toward the heat sink base before it can be effectively removed by the fluid through phase change. A simple enhanced boiler surface integrated with the HPC package is also considered for comparison in this study. A multiphase CFD model is developed in ANSYS-Fluent with Eulerian treatment of the two-phase flow employing the RPI boiling model for phase change. The numerical model is validated against the experimental results for boiling over a plain surface with a maximum deviation within ±10%. The numerical results show that the heat sink integrated with a heat pipe heat spreader is capable of maintaining junction temperature well below 105 °C at a TDP of 1000 W.