Effects of Phosphor Concentration and Leadframe Reflectivity for Phosphor-Converted LEDs

We propose the effects of phosphor concentration and leadframe reflectivity on phosphor-converted LEDs (pc-LEDs) manufactured using the dispensing method in this study. Simulation results showed that the luminous flux increased with the phosphor concentration and reflectivity of the reflective cup, even as the total output power decreased as the phosphor concentration increasing. It was also found that the leadframe reflectivity would dominate the optical and chromatic characteristics of pc-LEDs as well as the phosphor concentration. Specifically, for the pc-LEDs with a low phosphor concentration, the leadframe reflectivity and phosphor concentration were crucial factors determining the total output power and chromaticity deviation. However, for the pc-LEDs with a high phosphor concentration, only the phosphor concentration determined the chromaticity deviation.