Method for producing ceramic composite material, ceramic composite material, and light emitting device

Patent metadata

Field	Value
Publication number	US-11149193-B2
Application number	US-201916375476-A
Country	US
Kind code	B2
Filing date	Apr 4, 2019
Priority date	Apr 6, 2018
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

Provided are a method for producing a ceramic composite material that has a high light emission intensity, a ceramic composite material, and a light emitting device. The method for producing a ceramic composite material, includes: preparing a green body containing a nitride fluorescent material having a composition represented by the following chemical formula (I) and aluminum oxide particles mixed with each other; and performing primary sintering the green body at a temperature in a range of 1,250° C. or more and 1,600° C. or less to provide a first sintered body:

M w Ln 1 x A y N z   (I)

wherein in the chemical formula (I), M represents at least one element selected from the group consisting of Ce and Pr; Ln 1 represents at least one element selected from the group consisting of Sc, Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; A represents at least one element selected from the group consisting of Si and B; and w, x, y, and z each satisfy 0<w≤1.0, 2.5≤x≤3.5, 5.5≤y≤6.5, and 10≤z≤12.

First claim

The invention claimed is:

1. A method for producing a ceramic composite material, comprising:
preparing a green body comprising a nitride fluorescent material having a composition represented by the following chemical formula (I), a rare earth aluminate salt fluorescent material having a composition represented by the following chemical formula (II) and aluminum oxide particles; and
performing primary sintering the green body at a temperature in a range of 1,250° C. or more and 1,600° C. or less to obtain a first sintered body:
M w Ln 1 x A y N z   (I)

wherein in the chemical formula (I), M represents at least one element selected from the group consisting of Ce and Pr; Ln 1 represents at least one element selected from the group consisting of Sc, Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; A represents at least one element selected from the group consisting of Si and B; and w, x, y, and z each satisfy 0<w≤1.0, 2.5≤x≤3.5, 5.5≤y≤6.5, and 10≤z≤12,
(Ln 2 1-a Ce a ) 3 (Al c Ga b ) 5 O 12   (II)

wherein in the chemical formula (II), Ln 2 represents at least one element selected from the group consisting of Y, Gd, Lu, and Tb; and a, b, and c each satisfy 0<a≤0.022, 0≤b≤0.4, 0<c≤1.1, and 0.9≤b+c≤1.1.

2. The method for producing a ceramic composite material according to claim 1 , further comprising performing secondary sintering the first sintered body by a hot isostatic pressing (HIP) treatment at a temperature in a range of 1,250° C. or more and 1,600° C. or less, so as to obtain a second sintered body.

3. The method for producing a ceramic composite material according to claim 1 , wherein the primary sintering is performed at a temperature in a range of 1,300° C. or more and 1,500° C. or less.

4. The method for producing a ceramic composite material according to claim 2 , wherein the secondary sintering is performed at a temperature in a range of 1,350° C. or more and 1,500° C. or less.

5. The method for producing a ceramic composite material according to claim 1 , wherein the nitride fluorescent material has a median particle diameter in a range of 2 μm or more and 100 μm or less.

6. The method for producing a ceramic composite material according to claim 1 , wherein the aluminum oxide particles have an average particle diameter in a range of 0.1 μm or more and 1.5 μm or less.

7. The method for producing a ceramic composite material according to claim 1 , wherein in the step of preparing a green body, the nitride fluorescent material is used in an amount of 0.1% by mass or more and 70% by mass or less based on a total amount of 100% by mass of the nitride fluorescent material and the aluminum oxide particles.

8. The method for producing a ceramic composite material according to claim 1 , wherein the aluminum oxide particles have a purity of aluminum oxide of 99.0% by mass or more.

9. The method for producing a ceramic composite material according to claim 1 , wherein the rare earth aluminate salt fluorescent material has a median particle diameter in a range of 15 μm or more and 40 μm or less.

10. The method for producing a ceramic composite material according to claim 1 , wherein in the step of preparing a green body, a total amount of the rare earth aluminate salt fluorescent material and the nitride fluorescent material is in a range of 0.2% by mass or more and 80% by mass or less based on 100% by mass of the green body.

11. The method for producing a ceramic composite material according to claim 1 , wherein the first sintered body has a relative density of 80% or more.

12. The method for producing a ceramic composite material according to claim 2 , wherein the second sintered body has a relative density of 90% or more.

13. A ceramic composite material comprising a nitride fluorescent material having a composition represented by the following chemical formula (I), a rare earth aluminate salt fluorescent material having a composition represented by the following chemical formula (II) and aluminum oxide, having a content of the nitride fluorescent material in a range of 0.1% by mass or more and 70% by mass or less based on a total amount of the nitride fluorescent material and the aluminum oxide, and a total amount of the nitride fluorescent material and the rare earth aluminate salt fluorescent material is in a range of 0.2% by mass or more and 80% by mass or less based on 100% by mass of the ceramic composite material:
M w Ln 1 x A y N z   (I)

wherein in the chemical formula (I), M represents at least one element selected from the group consisting of Ce and Pr; Ln 1 represents at least one element selected from the group consisting of Sc, Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; A represents at least one element selected from the group consisting of Si and B; and w, x, y, and z each satisfy 0<w≤1.0, 2.5≤x≤3.5, 5.5≤y≤6.5, and 10≤z≤12,
(Ln 2 1-a Ce a ) 3 (Al c Ga b ) 5 O 12   (II)

wherein in the chemical formula (II), Ln 2 represents at least one element selected from the group consisting of Y, Gd, Lu, and Tb; and a, b, and c each satisfy 0<a≤0.022, 0≤b≤0.4, 0<c≤1.1, and 0.9≤b+c≤1.1.

14. The ceramic composite material according to claim 13 , wherein the ceramic composite material has a relative density of 80% or more.

15. The ceramic composite material according to claim 13 , wherein the ceramic composite material contains the nitride fluorescent material in an amount in a range of 15% by mass or more based on a total amount of 100% by mass of the rare earth aluminate fluorescent material and the nitride fluorescent material.

16. A light emitting device comprising the ceramic composite material according to claim 13 and a light emitting element having a light emission peak wavelength in a range of 350 nm or more and 500 nm or less.

Assignees

• Nichia Corp

Inventors

• Ooguri Hirofumi
• Fukui Tomoya
• Yanagihara Tadayoshi
• Yoshida Shigeki

Classifications

• C09K11/77747

  Silicon Nitrides or Silicon Oxynitrides · CPC title

• C09K11/7774 Primary

  Aluminates · CPC title

• C09K11/02 Primary

  Use of particular materials as binders, particle coatings or suspension media therefor · CPC title

• H10H20/0361

  of wavelength conversion means · CPC title

• H10H20/8512

  Wavelength conversion materials · CPC title