An experimental investigation of a scheme for cooling electronics packaged in a 3D stack arrangement will be presented in this paper. The scheme utilizes immersion cooling of the stacked electronics in an enclosure filled with a dielectric fluid. Convection and conduction within the dielectric fluid drive heat from the 3D stack to the walls of the enclosure from where a ‘synthetic jet /fan air-cooled heat sink’ ultimately dissipates heat to the ambient. Four layers of thick film heaters embedded in FR-4 sheets, each attached to thin copper plates (innovatively stacked in a pyramidal arrangement for conducting heat laterally to the dielectric fluid and simultaneously promoting natural convection in the fluid), were used to simulate a 3D stack of electronics. For a comparative study, several runs were carried out, where the enclosure was filled with dielectric fluid (FC-770), FC-770 in combination with copper wool (with a goal of enhancing heat transfer in FC-770), and water. For a 40 W total power input to the stack, it was observed that the thermal resistance for heat dissipation to ambient from the four heaters varied from 1.67 K/W to 1.96 K/W with FC-770, 1.47 K/W to 1.87 K/W with FC-770 combined with copper wool, and 1.06 K/W to 1.50 K/W with water. The proposed cooling solution is passive and scalable, and is demonstrated to be practicable and effective in cooling 3D stacked electronics.
Influence of Stroke on Performance Characteristics of Synthetic Jet
Fan
