Analysis of diamond-like carbon film on enhancing thermal radiation of substrate of high-power LED

Miniaturization and high-power are the important development directions of electronic components today. The volume of Light emitting diode (LED) is getting smaller and smaller, but the power is increasing dramatically. If the heat accumulated in the device and let the junction temperature of the electronic components exceeds the critical value, the reliability and lifetime of the device will be reduced markedly. Diamond-Like Carbon (DLC) films have high hardness, high wear-resistance, high thermal conductivity, high insulation and so on, and have been widely used in mechanical, electronic, optical and medical fields. This study focused on the effect of radiation heat transfer in the heat dissipation of high-power LEDs, DLC films were deposited on the packaging substrates of LED lamps, and the thickness influence of DLC films on the heat radiation performance was investigated by Infrared thermal imager. The LED models were established by using Solid-Works drawing software, and the thermal simulation analysis of LED with different thickness of DLC films was carried out by ANSYS. The experimental results show that the surface temperature of the LEDs with 1.6, 2.4 and 3.2 thick DLC films on the aluminum substrate is 1.2, 1.5 and 2.3°C lower than that of the LED without DLC film, respectively. The simulation results are consistent with the experimental results, indicating that thicker DLC film has better effect on increasing the thermal radiation of the substrates.