WHITE SEMICONDUCTOR LIGHT EMITTING DEVICE

• US 20120319565A1
• Filed: 08/10/2012
• Published: 12/20/2012
• Est. Priority Date: 06/25/2010
• Status: Active Grant

• Current Assignee: CMC Magnetics Corporation
• Original Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Inventors: Kagawa, Kazuhiko, Satou, Yoshihito, SAKUTA, Hiroaki, Hiraoka, Shin
• Granted Patent: US 8,829,780 B2
• Time in Patent Office: Days
• US Class Current: 313/503
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/7734 Aluminates
• CPC Class Codes: C09K 11/77342 Silicates
• CPC Class Codes: C09K 11/77347 Silicon Nitrides or Silicon Oxynitrides
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: C09K 11/7739 with halogens
• CPC Class Codes: C09K 11/7768 with alkaline earth metals
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01021 Scandium [Sc]
• CPC Class Codes: H01L 33/504 : Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/507 : the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: Y02B 20/00 : Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

The invention aims at providing controllable parameters that are correlated with special color rendering index R9, and at providing a white light-emitting semiconductor device having a high R9 value obtained through optimization of such parameters.

The white light-emitting semiconductor device is provided with a phosphor as a light-emitting material and with a light-emitting semiconductor element as an excitation source of the phosphor. The phosphor includes at least a green phosphor and a wide-band red phosphor. In the white light-emitting semiconductor device, an intensity at wavelength 640 nm of an emission spectrum which has been normalized with respect to luminous flux is 100-110% of the intensity at wavelength 640 nm of a spectrum of standard light for color rendering evaluation which has been normalized with respect to luminous flux.

Claims

1. A white light-emitting semiconductor device comprising a phosphor as a light-emitting material, and with a light-emitting semiconductor element as an excitation source of the phosphor, and said phosphor including at least a green phosphor and a wide-band red phosphor,

wherein said green phosphor includes at least one type of green phosphor selected from among a green phosphor that contains a crystal formed of an alkaline earth silicon oxynitride or Sialon as a base and that contains Eu²⁺ as an activator, and a green phosphor that contains Ce³⁺ as an activator;

and

an intensity at wavelength 640 nm of an emission spectrum which has been normalized with respect to luminous flux is 100-110% of the intensity at wavelength 640 nm of a spectrum of standard light for color rendering evaluation which has been normalized with respect to luminous flux.

2. The white light-emitting semiconductor device according to claim 1, wherein the correlated color temperature of emitted white light ranges from 2500 to 3500 K.

3. The white light-emitting semiconductor device according to claim 1, wherein said green phosphor includes β

-Sialon;

Eu.

4. The white light-emitting semiconductor device according to claim 1, wherein

an emission peak wavelength of said light-emitting semiconductor element ranges from 360 to 430 nm,

said phosphor further includes a blue phosphor, and

the white light-emitting semiconductor device emits white light that includes light respectively emitted by said blue phosphor, said green phosphor and said wide-band red phosphor.

5. The white light-emitting semiconductor device according to claim 4, wherein said light-emitting semiconductor element is an InGaN-based LED element, the emission peak wavelength of which ranges from 405 to 415 nm.

6. The white light-emitting semiconductor device according to claim 4, wherein said blue phosphor includes an alkaline earth halophosphate phosphor activated by Eu²⁺.

7. The white light-emitting semiconductor device according to claim 1, wherein the emission peak wavelength of said light-emitting semiconductor element ranges from 430 to 470 nm.

8. The white light-emitting semiconductor device according to claim 1, wherein

said phosphor further includes a yellow phosphor, and

the white light-emitting semiconductor device emits white light that includes at least light respectively emitted by said green phosphor, said yellow phosphor and said wide-band red phosphor.

9. The white light-emitting semiconductor device according to claim 1, wherein said wide-band red phosphor includes (CaAlSiN₃)₁₋

x(Si_(3n+2)/4N_nO)_x;

Eu.

10. A white light-emitting semiconductor device, comprising:

a first and second white light-emitting units, each of which includes a phosphor as a light-emitting material, and a light-emitting semiconductor element as an excitation source of the phosphor, and said phosphor includes at least a green phosphor and a wide-band red phosphor, wherein

in each of said first and second white light-emitting units, an intensity at wavelength 640 nm of an emission spectrum which has been normalized with respect to luminous flux is 100-110% of the intensity at wavelength 640 nm of a spectrum of standard light for color rendering evaluation which has been normalized with respect to luminous flux, and

the white light-emitting semiconductor device can emit combined secondary white light resulting from mixing of primary white light emitted by said first white light-emitting unit and primary white light emitted by said second white light-emitting unit.

11. The white light-emitting semiconductor device according to claim 10, wherein a difference between the correlated color temperature of the primary white light emitted by said first white light-emitting unit and the correlated color temperature of the primary white light emitted by said second white light-emitting unit is 2000 K or more.

12. The white light-emitting semiconductor device according to claim 11, wherein the correlated color temperature of the primary white light emitted by said first white light-emitting unit ranges from 2500 to 3500 K, and the correlated color temperature of the primary white light emitted by said second white light-emitting unit ranges from 4500 to 7000 K.

13. A white light-emitting semiconductor device having first to N-th white light-emitting units, each of which comprises a phosphor as a light-emitting material, and a light-emitting semiconductor element as an excitation source of the phosphor, and said phosphor includes at least a green phosphor and a wide-band red phosphor, this white light-emitting semiconductor device emitting combined secondary white light resulting from mixing of primary white light respectively emitted by said first to N-th white light-emitting units, wherein

in all or part of said first to N-th white light-emitting units, said green phosphor includes at least one type of green phosphor selected from among a green phosphor that contains a crystal formed of an alkaline earth silicon oxynitride or Sialon as a base and that contains Eu²⁺ as an activator, and a green phosphor that contains Ce³⁺ as an activator, and

an intensity at wavelength 640 nm of a spectrum of the secondary white light which has been normalized with respect to luminous flux is 100-110% of the intensity at wavelength 640 nm of a spectrum of standard light for color rendering evaluation which has been normalized with respect to luminous flux.

14. The white light-emitting semiconductor device according to claim 13, wherein in all or part of said first to N-th white light-emitting units, the intensity at wavelength 640 nm of the emission spectrum which has been normalized with respect to luminous flux is 99% or less or 111% or more of the intensity at wavelength 640 nm of a spectrum of standard light for color rendering evaluation which has been normalized with respect to luminous flux.