Optimized Self-Adaptive Phosphor Coating Structure of White LEDs by Conventional Dispensing Method

It is well known that phosphor coating structure plays an important role in the packaging of phosphor converted white light-emitting diodes. In order to further improve the uniformity of the angle-dependent correlated color temperature (CCT), we make a reasonable optimization for self-adaptive phosphor coating and propose a method that combined with conventional dispensing layer to optimize self-adaptive phosphor coating structure. In this experiment, we form the optimized phosphor coating structure by employing self-exposure technique and conventional dispensing method. This optimized structure has two phosphor-converted layers to better realize high angular color uniformity. The experimental results have shown that the optimized phosphor coating structure has better CCT uniformity compared to the self-adaptive phosphor coating. What is more, compared with the one layer self-adaptive phosphor coating, the optimized structure is superior to the luminous efficiency.