METHOD FOR MANUFACTURING LONG-LIVED MULTIPLE COLOR LED

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PROBLEM TO BE SOLVED : To provide a long-lived multiple color LED where deterioration of a epoxy resin is inhibited. SOLUTION : A cap layer of a rare earth doped inorganic material has the function of efficiently converting an ultraviolet components which becomes a factor of deterioration of the epoxy resin, into visible light of longer wavelengths. The lifetime of the LED caused from the deterioration of epoxy resin can be sufficiently extended, by interposing the cap layer in between the LED and the epoxy sealing material. Additionally, because the energy of the ultraviolet composition is converted into visible light and used effectively, the luminous efficiency of LED is improved. The cap layer itself functions as a luminous layer, and the luminous wavelength can be selected by an element to be doped. Moreover, a mixture of light more than three colors becomes possible, by the use of the epoxy resin or inorganic material where a fluorescent material is added to the upper layer of the cap layer as a sealing layer, and luminescence of red, green , and yellow and luminescence of white, and of proper color rendering can be obtained by a suitable combination thereof. COPYRIGHT : (C)2006, JPO&NCIPI