Light emitting diode lamp and light emitting device

• US 8,148,887 B2
• Filed: 08/08/2008
• Issued: 04/03/2012
• Est. Priority Date: 02/18/2004
• Status: Active Grant

• Current Assignee: National Institute for Materials Science
• Original Assignee: National Institute for Materials Science
• Inventors: Hirosaki, Naoto, Sakuma, Ken, Ueda, Kyota, Yamamoto, Hajime
• Primary Examiner(s): MACCHIAROLO, PETER J
• Application Number:
  US12/222,408
• Publication Number:
  US 20090167153A1
• Time in Patent Office: 1,334 Days
• Field of Search: 313484-487, 313/489, 313/498, 313/512, 313/467, 313/468, 313/499, 313501-503, 362/235, 362/227, 362/231, 362/293, 362/545, 362/555, 362/800, 257/98, 257/99, 257/100, 257/80, 257/79, 257/783, 345/44, 345/46, 345/80
• US Class Current: 313/486
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A bullet type light emitting diode lamp or a chip-type light emitting diode lamp includes a semiconductor light emitting element, and a plurality of fluorescent materials that absorb part or whole of light emitted from the semiconductor light emitting element, and emit fluorescence at a wavelength different from that of the absorbed light. The fluorescent materials include a phosphor of a CaAlSiN₃ crystalline phase.

Claims

1. A bullet type light emitting diode lamp or a chip-type light emitting diode lamp to be mounted on a substrate, comprising:

a semiconductor light emitting element, and a plurality of fluorescent materials that absorb part or whole of light emitted from the semiconductor light emitting element, and emit fluorescence at a wavelength different from that of the absorbed light,

wherein the plurality of fluorescent materials comprise a phosphor composed of a CaAlSiN₃ crystalline phase.

2. The bullet type light emitting diode lamp or the chip-type light emitting diode lamp to be mounted on a substrate according to claim 1, wherein

the phosphor has a main emission wavelength of 585 nm to 780 nm, and emits light in a range of “

red”

by a general chromaticity classification, according to system color names of JIS Z8110.

3. The bullet type light emitting diode lamp or the chip-type light emitting diode lamp to be mounted on a substrate according to claim 1, wherein

the bullet type light emitting diode lamp or the chip-type light emitting diode lamp to be mounted on a substrate emits light in a color of a chromaticity coordinate of x=0.34 to 0.38 and y=0.32 to 0.42 in a chromaticity diagram (CIE) of an XYZ colorimetric system according to JIS Z8701.

4. A visible light emitting device, comprising:

a semiconductor light emitting element that emits bluish purple or blue light,

a support member for placing the semiconductor light emitting element therein,

a terminal for supplying electric power to the semiconductor light emitting element, and

a fluorescent material that absorbs part or whole of light emitted from the semiconductor light emitting element, and emits fluorescence at a wavelength different from that of the absorbed light, wherein

the fluorescent material comprises a phosphor of a CaAlSiN₃ crystalline phase that is obtained by firing using an electric furnace of a resistance heating type.

5. The light emitting device according to claim 4, wherein the phosphor of the CaAlSiN₃ crystalline phase is obtained by heating after firing atmosphere is made vacuum.

6. The light emitting device according to claim 4, wherein the phosphor of the CaAlSiN₃ crystalline phase is obtained by firing using a crucible made of boron nitride.

7. The light emitting device according to claim 4, wherein the phosphor of the CaAlSiN₃ crystalline phase is obtained by pulverizing after firing in nitride atmosphere.

8. The light emitting device according to claim 4, wherein the phosphor of the CaAlSiN₃ crystalline phase has a main emission wavelength of 585 nm to 780 nm, and emits light in a range of “

red”

by a general chromaticity classification, according to system color names of JIS Z8110.

9. The light emitting device according to claim 4, wherein the fluorescent material is essentially the CaAlSiN₃ crystalline.

10. The light emitting device according to claim 4, further comprising a plurality of further bullet type light emitting diode lamps or chip-type light emitting diode lamps, wherein the respective plurality of fluorescent materials comprises CaAlSiN₃ crystalline phase and a second phosphor, the CaAlSiN₃ crystalline phase and the second phosphor being mixed in respectively different ratios so as to respectively produce different color light when irradiated by the respective semiconductor light emitting element.

11. The visible light emitting device according to claim 4, in combination with a plurality of further visible light emitting devices, each of the plurality of further visible light emitting devices comprising a fluorescent material comprising CaAlSiN₃ crystalline phase and a second phosphor, the CaAlSiN₃ crystalline phase and the second phosphor being mixed in respectively different ratios so as to respectively produce different color light when irradiated by the respective semiconductor light emitting element.