荧光粉涂覆方式对白光LED光色指标影响.docVIP

荧光粉涂覆方式对白光LED光色指标影响 　　摘 要：文章采用TRACEPRO软件建立了三种白光LED的光学模型：（1）芯片直接涂覆荧光粉；（2）芯片涂覆硅胶后涂覆荧光粉层；（3）芯片涂覆荧光粉后涂覆硅胶层。通过改变荧光粉的摩尔浓度或硅胶厚度来考察白光LED的光色指标，如光通量、色温及显色指数的变化。研究结果表明：第一种和第二种涂覆方式中，光色指标随着荧光粉摩尔浓度或硅胶厚度的改变呈规律性变化；第三种涂覆方式中，色温及显色指数的变化趋势不稳定，第三种方式光通量高于前两种，最大值可达到87.3 lm。三种方式的显色指数在70左右。研究结论为白光LED工艺设计提供参考和依据。 　　关键词： LED；荧光粉；涂覆方式；光色指标 　　中图分类号：TN312+.8 文献标识码：B 　　The Impact of Phosphor Coating Method on the White LED Performance 　　WU Yan-fang， GONG Yu-bing 　　（School of Mechanical Electrical Engineering， Guilin University of Electronic Technology， Guilin Guangxi 541004， China） 　　Abstract： In this paper， the TRACEPRO software was used to establish three white LED optical models： （1） chip with directly coated phosphor， （2） chip with coated silica gel then with a phosphor layer， （3） chip with coated phosphor then with a silica gel layer. The influence of the phosphor concentration or silicone layer thickness on the white LED luminous flux， color temperature and color rendering index （CRI） was studied， respectively. The simulations show that for the first and second phosphor coating methods， luminous flux， color temperature and color rendering index change regularly with the phosphor concentration or silica gel thickness. For the third coating method， the color temperature and color rendering index have an unstable trend with the phosphor concentration or silica gel thickness. The luminous flux of the third phosphor coating LED is higher than that of the mentioned above two methods LED， which reaches 87.3lm. The CRI of the three coating LED is about 70. The results provide the reference and basis for white LED process design. 　　Keywords： light emitting diode； phosphor； coating； performance 　　引 言 　　白光LED作为一种新型的照明光源，正逐步广泛应用于室内照明、路灯、显示器背光、汽车前照灯等领域。基于荧光粉转换产生???光的方法有以下三种：（1）蓝光LED激发黄色荧光粉；（2）蓝光LED激发红、绿荧光粉；（3）紫外LED激发红、绿、蓝荧光粉。考虑到成本及制作方法的简便，目前市场上制作白光LED的主流方法是蓝光LED激发黄色荧光粉，而荧光粉的涂覆形式及工艺对白光LED光学性能的影响成为新的研究热点。刘宗源[1]采用仿真的方法研究了荧光粉厚度及浓度对光学一致性的影响。Yuan-Chang Lin、Jiun Pyng You、Nguyen T. Tran等人[2]研究了荧光粉浓度