Manufacturing method of nitride phosphor or oxynitride phosphor

Patent metadata

Field	Value
Publication number	US-9683168-B2
Application number	US-31067307-A
Country	US
Kind code	B2
Filing date	Sep 7, 2007
Priority date	Sep 29, 2006
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

To reduce impurity contents of carbon and oxygen not contributing to light emission, then suppress deterioration of emission intensity of a phosphor, and improve emission efficiency of this phosphor. Therefore, there is provided a firing method of nitride or oxynitride phosphors, wherein a crucible 11 made of nitride is used as a firing container, and firing is performed, with this crucible covered with a lid (container 10 ), to manufacture the phosphor. The phosphor is expressed by a general composition formula MABO o N 3-2/3O :Z in which element M is one or more kinds of elements having bivalent valency, element A is one or more kinds of elements having tervalent valency, element B is one or more kinds of elements having tetravalent valency, O is oxygen, N is nitrogen, and element Z is an activating agent, satisfying o≧0.

First claim

The invention claimed is:

1. A method of manufacturing a nitride phosphor or an oxynitride phosphor, the method comprising:
placing raw material powders in a firing container made of boron nitride and covering the firing container with a lid made of boron nitride;
placing the firing container with the raw material powders therein in a firing furnace;
accommodating the firing container in a carbon container, such that the carbon container and the firing container with the raw material powders therein are located in the firing furnace;
vacuumizing an inside of the firing furnace and providing nitrogen atmosphere to the inside of the firing furnace; and
firing the raw material powders in a circulating nitrogen atmosphere,
wherein the phosphor is expressed by a general composition formula MABO o N 3-2/3o :Z in which element M is one or more different elements having bivalent valency, element A is one or more kinds of elements having tervalent valency, element B is one or more kinds of elements having tetravalent valency, O is oxygen, N is nitrogen, and element Z is an activating agent, satisfying o≧0, and
the phosphor contains less than 0.06 wt % of carbon.

2. The method according to claim 1 , wherein the element M is one or more different elements selected from a group consisting of Mg, Ca, Sr, Ba, Zn, the element A is one or more different elements selected from a group consisting of B (boron), Al, Ga, the element B is Si and/or Ge, and the element Z is one or more different elements selected from a group consisting of rare earth elements and transitional metal elements.

3. The method according to claim 1 , wherein the element A is Al, and the element B is Si.

4. The method according to claim 1 , wherein the element M is Ca, and the element Z is Eu.

5. The method according to claim 1 , wherein the lid is a container that is larger than the firing container and is turned upside down to cover at least an upper part of the firing container.

6. The method according to claim 1 , wherein the raw material powders are fired in a firing furnace having a carbon heater.

7. The method according to claims 1 , wherein the phosphor contains less than 2.7 wt % of oxygen.

8. A method according to claim 1 , wherein the phosphor contains indispensable oxygen.

9. A method according to claim 1 , wherein Z is Eu, and only Eu 2 O 3 (3N) is used as an Eu raw material.

10. A method according to claim 1 , wherein a molar ratio of raw materials Ca:Al:Si:Eu=0.985:1:1:0.015.

Assignees

• Gotoh Masahiro
• Sakane Kenji
• Nichia Corp
• Citizen Electronics

Inventors

• Gotoh Masahiro
• Sakane Kenji

Classifications

• C04B35/597 Primary

  based on silicon oxynitride, {e.g. SIALONS} · CPC title

• C09K11/77348 Primary

  Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides · CPC title

• C09K11/64

  containing aluminium · CPC title

• C04B2235/3865

  Aluminium nitrides · CPC title

• C04B2235/3224

  Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide · CPC title