Phosphor plate, light emitting device, and method for manufacturing phosphor plate

Patent metadata

Field	Value
Publication number	US-12284848-B2
Application number	US-202017769902-A
Country	US
Kind code	B2
Filing date	Oct 7, 2020
Priority date	Oct 23, 2019
Publication date	Apr 22, 2025
Grant date	Apr 22, 2025

Abstract

A phosphor plate including: a complex containing an α-sialon phosphor and a sintered body containing spinel represented by a general formula M 2x Al 4-4x O 6-4x (where M represents at least one of Mg, Mn, and Zn, and 0.2<x<0.6). In addition, there is provided a light emitting device including: a group III nitride semiconductor light emitting element; and the phosphor plate provided on one surface of the group III nitride semiconductor light emitting element. Further, there is provided a method for manufacturing the phosphor plate.

First claim

The invention claimed is:

1. A phosphor plate comprising:
a complex containing an α-sialon phosphor and a sintered body containing spinel represented by a general formula M 2x Al 4-4x O 6-4x (where M represents at least one of Mg, Mn, and Zn, and 0.2<x<0.6),
wherein a total value of a content of the α-sialon phosphor and the sintered body containing the spinel is equal to or more than 99% by volume and equal to or less than 100% by volume with respect to the entire complex.

2. The phosphor plate according to claim 1 , wherein
a content of the α-sialon phosphor is equal to or more than 5% by volume and equal to or less than 50% by volume with respect to an entire complex.

3. The phosphor plate according to claim 1 , wherein
the α-sialon phosphor includes an α-sialon phosphor containing an Eu element represented by a following general formula (1),
(M) m(1-x)/p (Eu) mx/2 (Si) 12-(m+n) (Al) m+n (O) n (N) 16-n   General formula (1)

in general formula (1), M represents one or more elements selected from the group consisting of Li, Mg, Ca, Y, and lanthanide elements (excluding La and Ce), p represents a valence of the M element, and 0<x<0.5, 1.5≤m≤4.0 and 0≤n≤2.0.

4. The phosphor plate according to claim 1 , wherein
a median diameter D 50 of the α-sialon phosphor in the complex on a volume basis is equal to or more than 2 μm and equal to or less than 30 μm.

5. The phosphor plate according to claim 1 , wherein
a surface roughness Ra on a main surface of the phosphor plate is equal to or more than 0.01 μm and equal to or less than 2.0 μm.

6. The phosphor plate according to claim 1 , wherein
when a sum of an a* value and a b* value in an L*a*b* color coordinates of the main surface of the phosphor plate, which is measured in accordance with JIS Z 8781-4, is equal to or more than 17.0 and equal to or less than 19.5.

7. The phosphor plate according to claim 1 , wherein
the phosphor plate is used as a wavelength converter that converts emitted blue light into orange light and emits the converted orange light.

8. A light emitting device comprising:
a group III nitride semiconductor light emitting element; and
the phosphor plate according to claim 1 provided on one surface of the group III nitride semiconductor light emitting element.

9. A method for manufacturing the phosphor plate according to claim 1 , the method comprising:
a firing step of heating a mixture containing an α-sialon phosphor and a spinel raw material powder, wherein
the spinel raw material powder is (i) a powder containing spinel represented by the general formula, and/or (ii) a mixture of a metal oxide powder represented by a general formula MO (M represents at least one of Mg, Mn, and Zn) and an Al 2 O 3 powder, and
a BET specific surface area of the spinel raw material powder is equal to or more than 0.1 m 2 /g and equal to or less than 10.0 m 2 /g.

10. A method for manufacturing a phosphor plate comprising a complex containing an α-sialon phosphor and a sintered body containing spinel represented by a general formula M 2x Al 4-4x O 6-4x , where M represents at least one of Mg, Mn, and Zn, and 0.2<x<0.6, the method comprising:
a firing step of heating a mixture containing an α-sialon phosphor and a spinel raw material powder, wherein
the spinel raw material powder is (i) a powder containing spinel represented by the general formula, and/or (ii) a mixture of a metal oxide powder represented by a general formula MO, where M represents at least one of Mg, Mn, and Zn, and an Al 2 O 3 powder, and
a BET specific surface area of the spinel raw material powder is equal to or more than 0.1 m 2 /g and equal to or less than 10.0 m 2 /g.

Assignees

• Denka Company Ltd

Inventors

• Yamaura Taiyo
• Kubota Yuki
• Ito Kazuhiro
• Emoto Hideyuki

Classifications

• H10H20/825

  containing nitrogen, e.g. GaN · CPC title

• H10H20/8514

  characterised by their shape, e.g. plate or foil · CPC title

• C09K11/676

  Aluminates; Silicates · CPC title

• H10H20/851

  Wavelength conversion means · CPC title

• C04B35/443

  Magnesium aluminate spinel · CPC title