Patent ID: 8399944
Filing Date: 2013-03-19
Classification: H01L

Abstract:
1. A light emitting diode comprising: a substrate which transmits light, the substrate having a top surface and a back surface opposite the top surface; a first semiconductor layer, an active layer generating a first light, and a second semiconductor layer disposed, in that order, on the top surface of the substrate, a fluorescent layer formed on the back surface of the substrate, and converting a portion of the first light to second light having a different wavelength from the first light; and wherein the substrate has at least one etched hole defined in a portion of the back surface of the substrate, and portions of the back surface of the substrate surrounding the at least one etched hole are planar, and the fluorescent layer fills all the inside of the at least one etched hole, wherein the fluorescent layer includes at least one relatively thick area and at least one relatively thin area such that the first light is converted into the second light with higher efficiency in the at least one thick area than in the at least one thin area wherein the at least one relatively thick area of the fluorescent layer is formed in the at least one etched hole and the at least one relatively thin area of the fluorescent layer is formed on the portions of the back surface of the substrate surrounding the at least one etched hole.