Improvement of hotspot cooling in confinement space by corona discharge induced ionic wind

Hotspot cooling is a significant problem in the thermal management of electronic devices. With device dimension scaling down, the dissipation space becomes more and more confined making hotspot cooling challenged. However, effective solutions are limited. In this study, the feasibility of hotspot cooling by ionic wind in confined space is justified. It is demonstrated that the hotspot in a confined channel can be suppressed effectively by ionic wind, which cannot be achieved by conventional pressure-driven flow even with a large Reynolds number. The underlying physics is revealed by the secondary vortices. The cooling strategies for a single hotspot and multiple hotspots are proposed. There exists strong interplay between the secondary corona jet and the bulk flow. Coupled mechanisms (impingement effect, barrier effect, and entrance effect) are explained to design a suitable electrode configuration for single hotspot cooling. However, the design strategy for single hotspot cannot be directly used for multiple hotspots and a new design concept of "intensify electrode pair" is proposed. It is also found that partial ground configuration is suitable for a single hotspot, while entire ground is better for multiple hotspots. This work provides a potential means for hotspot cooling of electronic devices in confined space.