Study on the Optical Properties of Conformal Coating Light-Emitting Diode by Monte Carlo Simulation

The light extraction efficiency (LEE), correlated color temperature (CCT), and angular color uniformity (ACU) of the conformal coating phosphor silicone gel were investigated by Monte Carlo ray-tracing simulations. Relative to the conventional dispensing method, the conformal coating method can make the light-emitting diode (LED) module obtain better optical properties. It was found that the thickness of the phosphor layer in conformal coating was a key factor determining the optical performance. The thickness could be optimized for good optical properties. The optimal thickness is around 50-70 μm when taking LEE, CCT, and ACU into consideration.