Light-emitting apparatus

• US 7,332,746 B1
• Filed: 09/01/2000
• Issued: 02/19/2008
• Est. Priority Date: 09/02/1999
• Status: Expired due to Term

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Takahashi, Yuji, Yoshimura, Naoki, Kondo, Kuniyoshi, Ota, Koichi
• Primary Examiner(s): JACKSON JR, JEROME
• Application Number:
  US09/654,501
• Time in Patent Office: 2,727 Days
• Field of Search: 257/98, 313501-503
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/05124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/0558 being stacked
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/16145 the bodies being stacked
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/49113 the connectors connecting different bonding areas on the semiconductor or solid-state body to a common bonding area outside the body, e.g. converging wires
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 33/50 Wavelength conversion elements

Abstract

A novel configuration of a light-emitting apparatus that can emit white light, in which a primary light source composed of a group III nitride compound semiconductor is used in combination with a secondary light source including a fluorescent material which emits light of a green luminescent color when the fluorescent material is excited by light emitted from the primary light source. A tertiary light source for emitting red light may be further used in combination with the primary and secondary light sources.

Claims

1. A light-emitting apparatus, comprising:

a first light source comprising a first semiconductor light-emitting element that emits a blue light;

a second light source comprising;

a first fluorescent material that absorbs said blue light emitted by said first light source and emits a green light; and

a fluorescent material resin, said first fluorescent material being dispersed within said fluorescent material resin; and

a third light source comprising a second semiconductor light-emitting element that emits a red light,

wherein said second light source surrounds outer peripheries of said first light source and said third light source, and said blue light emitted by said first light source, said green light emitted by said second light source, and said red light emitted by said third light source are mixed to thereby generate white light.

2. A light-emitting apparatus according to claim 1, wherein said first fluorescent material comprises at least one of ZnS:

Cu, Au, Al;

ZnS;

Cu, Al;

ZnS;

Cu;

ZnS;

Eu; and

Y₂O₂S;

Ce.

3. A light-emitting apparatus according to claim 1, wherein a concentration of said first fluorescent material continuously changes within said fluorescent material resin, as a function of distance to said first semiconductor light-emitting element and said second semiconductor light-emitting element.

4. A light-emitting apparatus according to claim 1, further comprising a lead frame comprising a cup portion having a bottom surface, on which said first light source and said third light source are mounted.

5. A light-emitting apparatus according to claim 1, wherein the light-emitting apparatus comprises a chip-type LED.

6. A light-emitting apparatus according to claim 1, wherein said first fluorescent material comprises at least one of ZnS:

Eu and Y₂O₂S;

Ce.

7. A light-emitting apparatus according to claim 1, wherein said third light source comprises a second fluorescent material that absorbs said blue light emitted by said first light source and emits said red light.

8. A light-emitting apparatus according to claim 7, wherein said first fluorescent material and said second fluorescent material are dispersed in said fluorescent material resin.

9. A light-emitting apparatus according to claim 8, wherein a portion of said blue light emitted by said first light source is transmitted through said fluorescent material resin, and

wherein another portion, of said blue light emitted by said first light source is absorbed by said first fluorescent material, which emits said green light, and said second fluorescent material, which emits said red light, and said blue light emitted by said first light source, said green light emitted by said first fluorescent material and said red light emitted by said second fluorescent material, are mixed, to thereby generate a mixed light, emitted from said light-emitting apparatus, different in luminescent color from said blue light emitted from said first light source.

10. A light-emitting apparatus according to claim 1, wherein said first light source comprises a multiple quantum well structure.

11. A light-emitting apparatus according to claim 10, wherein said multiple quantum well structure comprises well layers comprised of InGaN.

12. A light-emitting apparatus according to claim 1, further comprising a sealing member that focuses light emitted from said light-emitting apparatus.