Performance Analysis of Impinging Chip-Attached Micro Pin Fin Direct Liquid Cooling Package for Hotspot Targeted Applications

As heterogeneous integration evolves, the diversity and density of devices that combine multiple functionalities has significantly increased. The subsequent increase in power usage and reduced size of components, specifically of Central Processing Units (CPUs), underlines the limitations of traditional cooling and reveals the need for significant improvements in thermal management. In this study, an innovative fluid-thermal cooling solution that addresses high density and non-uniform heat dissipation in a CPU package will be presented. The solution design includes jet impingement, which is used to directly cool four electronic chips simultaneously, as well as chip-attached micro pin fins. The copper micro pin fins have been additively manufactured onto the surface of the silicon chip using Selective Laser Melting (SLM), thus eliminating the need for thermal interface materials (TIMs). The effects of jet nozzle size and jet-to-chip distance on heat transfer and fluid flow are numerically investigated. The presented solution shows the potential to improve thermal performance with a lower level of system complexity and lower overhead for coolant and fabrication. To the author's knowledge, the thermal resistance results are the lowest reported (0.015 K/W) in the area of single-phase cooling research.