Thermal Conductivity Investigation of Phosphor/Silicone Composites

In high-power white light emitting diode (LED) package, phosphor/silicone composite is generally used for luminosity and chromaticity conversion, but high-power white LED generates a lot of heat when working, and heat is dissipated into the environment through the LED light chip package. The material at the bottom of the chip is copper, which has good thermal conductivity. However, the top of the chip is wrapped by phosphor/silicone composite, so the thermal conductivity of the phosphor/silicone composite material has a great influence on the heat dissipation capability of the LED device. Phosphor/silicone composite with good thermal conductivity improve the overall heat dissipation capability of LEDs. Therefore, it is of great significance to study the thermal conductivity of phosphor/silica gel composites. In this paper, the thermal conductivity of phosphor/silicone composites was analyzed by finite element simulation, and the relationship between the mass fraction of phosphor and the thermal conductivity of composites was obtained. In addition, considering the existence of defects in the composite material, the pores are typical. The simulation results indicate that the thermal conductivity of the composites increases rapidly with the increase of phosphor mass fractions and decreases with the increase of porosity. The simulation results are consistent with the theoretical predictions.