Numerical Investigation of Coolants for Chip-embedded Two-Phase Cooling

Inter-chip cooling, where a liquid coolant is passed between the layers of stacked chips, is an enabling technology for realizing significant computational performance improvements through three-dimensional (3D) integration of microelectronic components. The development of this cooling technology requires high fidelity thermal models to evaluate the device and system performance under different operating environments. In the present work, a Eulerian multiphase model developed for predicting two-phase flow and heat transfer behavior in parallel micro-channels and micro-pin fields was used to compare the thermal performance of four different refrigerants - R1234ze, R245fa, R134a and R600a, for chip-embedded two-phase cooling. Results shows that medium- and high-pressure refrigerants such as R1234ze R600a and R134a with a small density ratio, low viscosity, large latent heat of vaporization and low surface tension helps achieve low device temperatures while reducing the pressure drop across the device resulting in smaller variation in saturation as well as device temperature profile.