Patent ID: 7422504
Filing Date: 2008-09-09
Classification: C09K,F21S,F21Y,H01L,H05B,Y02B

Abstract:
1. A method for fabricating a light-emitting semiconductor device including: a blue-light-emitting device emitting light having a main emission peak in the wavelength range greater than 430 nm and less than or equal to 500 nm; and a luminescent layer including a yellow/yellowish phosphor which absorbs blue light emitted by the blue-light-emitting device to emit a fluorescence having a main emission peak in the wavelength range from 550 nm to 600 nm, both inclusive, and having a structure in which the blue light emitted by the blue-light-emitting device passes through the luminescent layer so that the color of the fluorescence emitted by the phosphor is added to the color of the blue light, thereby emitting white light, the method being characterized by comprising the steps of: a) covering at least a light-extracting surface of the blue-light-emitting device with a phosphor paste including the yellow/yellowish phosphor which has an absolute specific gravity in the range from 3.0 to 4.65, both inclusive, and emits light having a main emission peak in the wavelength range from 560 nm to 600 nm, both inclusive, at room temperature, and with a resin which has an absolute specific gravity in the range greater than or equal to 0.8 and less than or equal to the absolute value of the yellow/yellowish phosphor; and b) curing the phosphor paste, thereby forming the luminescent layer, wherein in the step a), a phosphor including, as a base material, a compound containing at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Sc, lanthanoid, Ti, Zr, Hf, V, Nb, Ta, Mo, W, Zn, B, Al, Ga, In, Si, Ge, Sn and P and at least one element selected from the group consisting of O, S, Se, F, Cl and Br is used as the yellow/yellowish phosphor, wherein the phosphor contains substantially no yttrium.