Scattering effect of SiO₂ particles on correlated color temperature uniformity of multi-chip white light LEDs

Abstract

This study proposes the addition of SiO₂ scattering particles into the phosphor layer of a multi-chip white light LED (MCW-LED) for enhancing its performance. It is demonstrated by computer simulations that SiO₂ particles can bring significant effects on the correlated color temperature (CCT) uniformity and luminous flux. Through the simulation experiments, it was found that the MCW-LED with hybrid SiO₂ structure with SiO₂ particle size around 1 μm can achieve higher color uniformity than other package structures. We investigated the influence of SiO₂ (quartz) concentration on the CCT and the output flux of the MCW-LED with CCTs 7000, 7700, and 8500 K, respectively. Compared to an LED package without SiO₂, SiO₂ packages can shrink the CCT deviation about 48%. In this study, it was demonstrated that the inclusion of about 5–10% SiO₂ can produce an MCW-LED with higher CCT uniformity and optimal lumen output.

Keywords:

• Multi-chip white light LED
• angular color uniformity
• silicon dioxide

Funding

This work was supported by the Siliconware Precision Industries Co., Ltd., and the National Science Council of the Republic of China, project: MOST 103-2622-E-151-019-CC3.