Light emitting device

• US 10,243,113 B2
• Filed: 10/27/2017
• Issued: 03/26/2019
• Est. Priority Date: 10/31/2016
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Suzuki, Shigeyuki, Watanabe, Hiroyuki, Hosokawa, Shoji
• Primary Examiner(s): Nguyen, Tram H
• Application Number:
  US15/795,444
• Publication Number:
  US 20180123000A1
• Time in Patent Office: 515 Days
• Field of Search: 257116, 257117, 257432-437, 257749, 257E33056-E33059, 257E25032, 257E27133-E27139, 257 79-103, 257918, 257E51018-E51022, 257E33001-E33077, 257E33054, 257E25028, 438 83, 438 9, 438100, 438101, 438111, 438112, 438123, 438124, 438411, 438412, 438461, 438584, 438597-688, 438 22- 47, 438 69, 438493, 438503, 438507, 438956
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45099 Material
• 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 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• 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 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source

Abstract

Provided is a light emitting device which includes a light emitting element having a peak emission wavelength in a range of 400 nm to 500 nm, and a fluorescent member containing a fluorescent material having a peak emission wavelength in a range of 630 nm to 670 nm, and a composition represented by the formula. Ca_sSr_tEu_uSi_vAl_wN_x. In the formula, s, t, u, v, w, and x satisfy 0.25≤s≤0.5, 0.4≤t≤0.75, 0.01≤u≤0.04, 0.8≤s+t+u≤1.1, 0.8≤v≤1.2, 0.8≤w≤1.2, 1.8≤v+w≤2.2, and 2.5≤x≤3.2. The light emitting device emits light having an x value of CIE 1931 chromaticity coordinates of 0.640 or more.

Claims

1. A light emitting device comprising:

a light emitting element having a peak emission wavelength in a range of 400 nm to 500 nm, and

a fluorescent member containing a fluorescent material having a peak emission wavelength in a range of 630 nm to 670 nm and a composition represented by formula (I);

Ca_sSr_tEu_uSi_vAl_wN_x 

 

(I)

wherein s, t, u, v, w, and x satisfy 0.25≤

s≤

0.5, 0.4≤

t≤

0.75, 0.01≤

u≤

0.04, 0.8≤

s+t+u≤

1.1, 0.8≤

v≤

1.2, 0.8≤

w≤

1.2, 1.8≤

v+w≤

2.2, and 2.5≤

x≤

3.2 and,

emitting light having an x value of CIE 1931 chromaticity coordinates of 0.640 or more.

3. The light emitting device according to claim 1, wherein the fluorescent member contains a resin, and a percentage of the fluorescent material relative to the resin is from 40% by weight to 80% by weight.

4. The light emitting device according to claim 1, wherein the light emitting element has an emission intensity at a peak emission wavelength of from 0.2% to 2% relative to a maximum emission intensity in an emission spectrum of the light emitting device.

5. The light emitting device according to claim 1, wherein a ratio of t to w is from 0.45 to 0.6.

6. The light emitting device according to claim 1, wherein the fluorescent material has a reflectivity of 10% or less relative to light at a wavelength of 450 nm.

7. The light emitting device according to claim 1, wherein the fluorescent material has a volume average particle diameter of from 5 μ

m to 50 μ

m.

8. The light emitting device according to claim 1, wherein the fluorescent member contains a resin, and a layer containing the fluorescent material immediately above the light emitting element has a thickness of 180 μ

m or less.

15. The light emitting device according to claim 1, wherein a ratio of s to w is 0.3 to 0.45.

2. A light emitting device comprising:

a light emitting element having a peak emission wavelength in a range of 400 nm to 500 nm, and

a fluorescent member containing a fluorescent material having a peak emission wavelength in a range of from 630 nm to 670 nm, and a composition represented by formula (I);

Ca_sSr_tEu_uSi_vAl_wN_x 

 

(I)

wherein s, t, u, v, w, and x satisfy 0.25≤

s≤

0.5, 0.4≤

t≤

0.75, 0.01≤

u≤

0.04, 0.8≤

s+t+u≤

1.1, 0.8≤

v≤

1.2, 0.8≤

w≤

1.2, 1.8≤

v+w≤

2.2, and 2.5≤

x≤

3.2 and,

emitting light with chromaticity coordinates (x, y) within a chromaticity range defined by an area determined by connecting points (0.500, 0.280), (0.540, 0.340), (0.625, 0.375), (0.735, 0.262), and (0.600, 0.200) with straight lines in a CIE 1931 chromaticity diagram.

9. The light emitting device according to claim 2, wherein the fluorescent member contains a resin, and a percentage of the fluorescent material relative to the resin is from 40% by weight to 80% by weight.

10. The light emitting device according to claim 2, wherein the light emitting element has an emission intensity at a peak emission wavelength of from 0.2% to 2% relative to a maximum emission intensity in an emission spectrum of the light emitting device.

11. The light emitting device according to claim 2, wherein a ratio of t to w is from 0.45 to 0.6.

12. The light emitting device according to claim 2, wherein the fluorescent material has a reflectivity of 10% or less relative to light at a wavelength of 450 nm.

13. The light emitting device according to claim 2, wherein the fluorescent material has a volume average particle diameter of from 5 μ

m to 50 μ

m.

14. The light emitting device according to claim 2, wherein the fluorescent member contains a resin, and a layer containing the fluorescent material immediately above the light emitting element has a thickness of 180 μ

m or less.

16. The light emitting device according to claim 2, wherein a ratio of s to w is 0.3 to 0.45.