White light emitting diode and method of manufacturing the same
View Patent ↗Provided is a white LED including a reflector cup; an LED chip mounted on the bottom surface of the reflector cup; transparent resin surrounding the LED chip; a phosphor layer formed above the transparent resin; and a reflecting film interposed between the transparent resin and the phosphor layer, the reflecting film reflecting phosphorescence, which is directed downward from the phosphor layer, in the upward direction.
1. A white light emitting diode (LED) comprising:
a reflector cup;
an LED chip mounted on the bottom surface of the reflector cup;
a transparent resin surrounding the LED chip;
a phosphor layer formed above the transparent resin; and
a reflecting film interposed between the transparent resin and the phosphor layer, the reflecting film reflecting phosphorescence, which is directed downward from the phosphor layer, in the upward direction,
wherein a plasma wavelength of the reflecting film is larger than the wavelength of the light generated from the LED chip and is smaller than the wavelength of the phosphorescence generated from the phosphor layer.
2. The white LED according to claim 1 , wherein the transparent resin is selected from the group consisting of polymethly methacrylate (PMMA), polystyrene, polyurethane, benzoguanamine resin, epoxy, and silicon resin.
3. The white LED according to claim 1 , wherein the phosphor layer is formed by mixing transparent resin and phosphor materials.
4. The white LED according to claim 3 , wherein the transparent resin is selected from the group consisting of PMMA, polystyrene, polyurethane, benzoguanamine resin, epoxy, and silicon resin.
5. The white LED according to claim 1 , wherein the reflecting film is a nano-film.
6. The white LED according to claim 1 , wherein the thickness of the reflecting film ranges from 1 to 10 nm.
7. The white LED according to claim 1 , wherein the reflecting film transmits light generated from the LED chip and reflects phosphorescence generated from the phosphor layer.
8. The white LED according to claim 1 , wherein the reflecting film is formed of a metallic material.
9. The white LED according to claim 8 , wherein the reflecting film is formed of cesium (Cs).
10. The white LED according to claim 1 , wherein the reflecting film is formed of a quasi-metallic material.
11. The white LED according to claim 10 , wherein the reflecting film is formed of semiconductor of which the doping concentration is equal to or more than 5×10 21 cm −3 .
12. The white LED according to claim 1 , wherein the LED chip includes at least one or more LEDs which generate blue, red, green, and ultraviolet (UV) wavelengths.
13. The white LED according to claim 1 , wherein the phosphor layer includes at least one or more phosphor materials which convert a wavelength into any one of yellow, red, and green.
14. A white LED comprising:
a reflector cup that is inclined upward;
an LED chip that is mounted on the bottom surface of the reflector cup;
a molding compound that is formed in the reflector cup so as to surround the LED chip;
a phosphor layer that is formed above the molding compound; and
a reflecting film that is interposed between the molding compound and the phosphor layer, the reflecting film transmitting light incident from the LED chip and reflecting phosphorescence incident from the phosphor layer,
wherein a plasma wavelength of the reflecting film is larger than the wavelength of the light generated from the LED chip and is smaller than the wavelength of the phosphorescence generated from the phosphor layer.
15. The white LED according to claim 14 , wherein the thickness of the reflecting film ranges from 1 to 10 nm.
16. The white LED according to claim 15 , wherein the reflecting film is formed of a metallic material.
17. The white LED according to claim 16 , wherein the reflecting film is formed of Cs.
18. The white LED according to claim 15 , wherein the reflecting film is formed of a quasi-metallic material.
19. The white LED according to claim 18 , wherein the reflecting film is formed of semiconductor of which the doping concentration is equal to or more than 5×10 21 cm −3 .
20. A method of manufacturing a white LED, comprising the steps of:
preparing a reflector cup;
mounting an LED chip on the bottom surface of the reflector cup;
forming a molding compound in the reflector cup such that the LED chip is surrounded by the molding compound;
forming a reflecting film on the molding compound; and
forming a phosphor layer on the reflecting film,
wherein a plasma wavelength of the reflecting film is larger than the wavelength of the light generated from the LED chip and is smaller than the wavelength of the phosphorescence generated from the phosphor layer.
21. The method according to claim 20 , wherein the molding compound is formed of any one selected from the group consisting of PMMA, polystyrene, polyurethane, benzoguanamine resin, epoxy, and silicon resin.
22. The method according to claim 20 , wherein the forming of the phosphor layer includes the steps of:
mixing transparent resin with phosphor materials, and then dispensing the transparent resin and the phosphor materials on the reflecting film; and
curing the transparent resin and the phosphor materials dispensed on the reflecting film.
23. The method according to claim 22 , wherein the transparent resin is formed of any one selected from the group consisting of PMMA, polystyrene, polyurethane, benzoguanamine resin, epoxy, and silicon resin.
24. The method according to claim 20 , wherein the thickness of the reflecting film ranges from 1 to 10 nm.
25. The method according to claim 20 , wherein the reflecting film is formed of a metallic material.
26. The method according to claim 25 , wherein the reflecting film is formed of Cs.
27. The method according to claim 20 , wherein the reflecting film is formed of a quasi-metallic material.
28. The method according to claim 27 , wherein the reflecting film is formed of semiconductor of which the doping concentration is equal to or more than 5×10 21 cm −3 .