平面涂层的白光LED封装技术

White LEDs Packing Technology of Planar Phosphor Coating Layer

基于自曝光的平面涂层白光LED封装工艺,该方法是采用聚乙烯醇与重铬酸铵的水溶性感光胶,通过采用自身蓝光芯片曝光得到自适应平面,最后运用等离子体去胶技术得到只剩下荧光粉层的平面涂层。通过采用九点法测试不同封装结构的白光LED的光斑均匀性、光谱色度以及光效。实验结果表明,自曝光的平面涂层工艺制备的白光LED,其颜色的均匀性要明显优于传统的点胶工艺和喷涂的平面工艺,其制得的白光LED的光效也不比这两种工艺差。

Based on the self-exposure planar phosphor coating technique, which adopted a kind of water-soluble sensitive glue consisting of Polyvinyl Alcohol （PVA） and Ammonium Dichromate （ADC）. This method adopted the blue light exposure by itself which could obtain controllable phosphor layer. Finally, by using the plasma stripping, only phosphor＇s planar coating layer could be obtained. Luminous efficiency, spectrum of light output and color uniformity of different packing structures were measured by the nine point＇s method. Experimental results show that the uniformity of white LED obtained by this technique is better than that obtained by the traditional dropping glue technology and sprays coating technology. And the luminous efficiency is as good as the other two technologies.