Jie Zhao, Yanjun Dai, Wenquan Tao, Yungang Wang
With the ongoing miniaturization of electronic devices, the integration level of their internal components has increased dramatically, creating an urgent need for matching heat removal technologies to achieve efficient heat dissipation and ensure stable operation under high heat fluxes. While research on heat removal for heat fluxes up to 500 W ⋅ cm − 2 is quite common, there is a growing demand for solutions capable of handling even higher fluxes. This paper defines 500 W ⋅ cm − 2 and 1000 W ⋅ cm − 2 as the boundaries for medium-to-high and high-to-ultra-high heat fluxes, respectively. It reviews the latest cutting-edge heat removal technologies capable of dissipating high and ultra-high heat fluxes, such as microchannel cooling, spray cooling, immersion cooling, heat pipes, jet impingement, vapor chambers, and thin film boiling. The paper categorizes relevant research within these high-flux ranges, highlighting the highest critical heat flux (CHF) values achieved and the methodologies used. In addition, a thermal equilateral triangle composed of CHF, wall temperature, and heat transfer coefficient is proposed to visually compare the advantages and disadvantages for six ultra-high heat flux technologies. Finally, a comprehensive analysis of the four most promising technologies is made and a roadmap for future development directions is proposed. This framework positions the cooling of electronic devices as the objective, advanced heat removal technologies as the enabling means, thermal enhancement factors as the driving mechanism, and artificial intelligence as the supporting tool, thereby offering a systematic reference for extending the performance boundaries of thermal management systems.