A review on thermal management of light-emitting diodes: From package-level to system-level

The widespread use of light-emitting diodes (LEDs) in advanced displays, optical communications, and medical UV applications has led to a rapid increase in heat flux densities, emphasizing the necessity for effective thermal management. This review divides the thermal management of LEDs into two sections: package-level and system-level. This approach differs from that of most published reviews, which often concentrate on specific components or system-level aspects of LEDs. The thermal management for package-level is initially discussed, including material selection and structural optimization of the chip structure, submount, thermal interface material and phosphor layer, as well as the design of packaging structures. The thermal management for system-level is summarized from both passive cooling and active cooling, focusing on their structure and working fluid. Finally, the future of LED thermal management is discussed at both the LED package-level and system-level, with a particular focus on study hotspots and development trends.