Optical wavelength conversion member and light-emitting device

Patent metadata

Field	Value
Publication number	US-10727378-B2
Application number	US-201716342390-A
Country	US
Kind code	B2
Filing date	Oct 20, 2017
Priority date	Oct 28, 2016
Publication date	Jul 28, 2020
Grant date	Jul 28, 2020

Abstract

An optical wavelength conversion member and a light-emitting device including the optical wavelength conversion member. The optical wavelength conversion member ( 9 ) is formed of a ceramic sintered body having a fluorescent phase containing fluorescent crystal grains as a main component and a translucent phase containing translucent crystal grains as a main component. Crystal grains of the fluorescent phase have a composition represented by formula A 3 B 5 O 12 :Ce, where the element A is selected from Sc, Y, and lanthanoids (except for Ce), and the element B is selected from Al and Ga. In the optical wavelength conversion member ( 9 ), 0.3<a<34 and 300 μm<y<1,050 μm are satisfied, wherein a represents the area ratio of the translucent phase to the fluorescent phase in a cross section of the optical wavelength conversion member ( 9 ), and y represents the interfacial length of the fluorescent phase.

First claim

The invention claimed is:

1. An optical wavelength conversion member comprising a ceramic sintered body having a fluorescent phase containing fluorescent crystal grains as a main component and a translucent phase containing translucent crystal grains as a main component, wherein
the crystal grains of the fluorescent phase have a composition represented by formula A 3 B 5 O 12 :Ce, and each of the element A and the element B is at least one element selected from the following element groups:
A: Sc, Y, and lanthanoids (except for Ce), and
B: Al and Ga; and
the following relations are satisfied:
0.3<a<34 and 300 μm<y<1,050 μm,

wherein a represents the ratio of the area of the translucent phase to the area of the fluorescent phase in a cross section of the optical wavelength conversion member, and y represents the interfacial length of the fluorescent phase.

2. An optical wavelength conversion member according to claim 1 , wherein the following relation is satisfied: 1.1<x<2.1, wherein x represents the ratio of the mean grain size r1 of crystal grains of the translucent phase to the mean grain size r2 of crystal grains of the fluorescent phase; the crystal grains of the translucent phase have a mean grain size r1 of 0.2 μm to 6 μm; and the crystal grains of the fluorescent phase have a mean grain size r2 of 0.1 μm to 4 μm.

3. An optical wavelength conversion member according to claim 1 , wherein the crystal grains of the translucent phase have a composition of Al 2 O 3 .

4. An optical wavelength conversion member according to claim 1 , wherein the ceramic sintered body contains a compound represented by formula A 3 B 5 O 12 :Ce in an amount of 3 vol. % to 70 vol. %.

5. An optical wavelength conversion member according to claim 1 , wherein the Ce content of the compound represented by formula A 3 B 5 O 12 :Ce is 0.1 mol % to 1.0 mol % relative to the element A of the compound.

6. A light-emitting device comprising an optical wavelength conversion member as recited in claim 1 .

Assignees

• Ngk Spark Plug Co

Inventors

• TAKAKU Shohei
• Katsu Yusuke
• Ito Tsuneyuki
• Shimura Yuki
• Mitsuoka Takeshi
• Moteki Jun

Classifications

• C04B35/01

  based on oxide ceramics · CPC title

• G02B5/20

  Filters (polarising elements G02B5/30) · CPC title

• C04B2235/785

  Submicron sized grains, i.e. from 0,1 to 1 micron · CPC title

• C04B35/50

  based on rare-earth compounds {(non-oxide rare earth compounds C04B35/5156)} · CPC title

• C04B2235/80

  Phases present in the sintered or melt-cast ceramic products other than the main phase · CPC title