Thermal management of a 3D chip stack using a liquid interface to a synthetic jet cooled spreader

The present investigation focuses on the design of a unique liquid interface thermal management solution for a 3D chip stack that is embedded within a cavity, in a heat spreader cooled by an array of synthetic jet actuators. The heat sink module was previously reported by the authors, who achieved an overall heat transfer coefficient of ~70 W/m².K. The radial heat sink exploits enhanced, small-scale heat transfer that is affected by a central array of synthetic jet actuators. This approach is very effective due to the short radial thermal path of the cooling air along the fins which couples rapid, time-periodic entrainment and ejection of cool and heated air, respectively to increase the local heat transfer coefficient on the air-side. The key focus of this paper is the numerical simulation of the dielectric liquid interface used to efficiently transmit the heat from the high power 3D stacked electronics to the heat sink base. The coupled natural convection in the fluid and conduction in solid spreaders sandwiched between the tiers of the stack form a novel efficient, passive and scalable thermal management solution.