Effects of the phosphor layer on luminescent features flat White-LED light source

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 20~38 μm, 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.