以COB形式封装的白光LED平面光源为研究对象, 系统研究了平面封装结构中荧光层对白光LED平面光源发光特性的影响。采用丝网印刷法制备了不同浓度与印刷层数的荧光层, 并采用平面封装的LED蓝光光源作为激发光源, 以类比法研究分析了不同发光层膜厚对白光平面光源平均照度、色坐标和光通量等参数的影响, 系统地阐述了发光层对平面光源发光性能的决定因素及工艺优化条件。结果表明, 当荧光粉浆料浓度为46%~53.6%, 厚度为20~38μm时, 结合平面蓝光LED激发可以获得照度大、颜色纯正的白光LED光源, 且白光LED平面光源具有较高的光通量值, 表现出优良的光学特性。

Taking the white flat LED lighting source packaged in COB form as the research object, the effects of the phosphor layer on the luminescent features of the white COB-LED light source in the plane package structure were studied. The phosphor powder layers with different concentration and printing layers were prepared by screen printing method. After integrating with blue flat LED light source, the luminous flux and color coordinate based on phosphor layer with different thickness were measured and analogically analyzed, which demonstrate the importance and optimized process conditions of phosphor layer for COB-LED light source. The results show that when the concentration of phosphor is 46%~53.6%, and the thickness of phosphor layer is 20~38μm, the pure white COB-LED light source with high illumination intensity can be achieved. It is concluded that the optimized phosphor layer covered on blue flat LED makes COB-LED light source own high luminous flux.