Study on Light Extraction Efficiency of White COB-LED

The COB(Chip on Board)packaging technology was adopted in LED products to meet the requirements of high efficiency and high color rendering index.In this work,the influence of silicone amount on luminous flux,luminous efficiency,color temperature and color rendering index(CRI)of white COB-LED was investigated.And proposed was a kind of encapsulation method with high luminous efficiency,high CRI and low color temperature.Thus the luminous efficiency was improved and specific optical distribution was achieved.Finally,14 W white COB-LED was obtaied with the color temperature of 4 900 K,color rendering index of 82,and photosynthetic efficiency of 125lm/W respectively at the current density of 30A/cm2.