Heat Dissipation Enhancement of High-Power LEDs Through Compact Ceramic Substrate Integrated With Microchannel

As the heat flux of high-power light-emitting diodes (LEDs) drastically rises, the chip junction temperature rises, which has a significantly negative impact on the longevity and dependability of LEDs. This work proposed a compact ceramic substrate integrated with a microchannel for heat dissipation enhancement of high-power LEDs. A set of copper tubes were closely arranged and directly bonded on the copper layer of ceramic substrate to form the microchannel, which combined the advantages of high integration and reliability. The compact ceramic substrate microchannel (CSM) was successfully applied to high-power LEDs with multichip module packaging. The working temperatures of these CSM-packaged LEDs under various currents were studied by thermal simulation and experiment and compared with the traditional fin-cooling (FC) packaged LEDs. The CSM maintains the LEDs with low working temperature even at a driving current of 3 A, and a maximum heat flux reaches 405.5 W/cm2. The CSM reduces the working temperature of LEDs from 206 °C to 63.5 °C with a decrease rate of 69.2%. Meanwhile, the light output power of LEDs is increased by 62.13% from 8.53 to 13.83 W. The results demonstrate that the ceramic substrate with integrated microchannel can significantly improve the heat dissipation of high-power LEDs.