Nitride fluorescent material, method for producing the same, and light emitting device

• US 9,944,851 B2
• Filed: 08/25/2016
• Issued: 04/17/2018
• Est. Priority Date: 08/28/2015
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Nishimata, Kazuya, Watanabe, Hiroyuki, Hosokawa, Shoji
• Primary Examiner(s): Rizkallah, Kimberly
• Assistant Examiner(s): Jang, Bo Bin
• Application Number:
  US15/247,083
• Publication Number:
  US 20170058197A1
• Time in Patent Office: 600 Days
• Field of Search: None
• CPC Class Codes: C09K 11/0833 with alkali or alkaline earth metals
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• 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 2224/48091 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 2924/181 Encapsulation
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A method for producing a nitride fluorescent material having high emission luminance can be provided. The method includes heat-treating a raw material mixture containing silicon nitride, silicon, an aluminum compound, a calcium compound, and a europium compound.

Claims

1. A method for producing a nitride fluorescent material, the method comprising heat-treating a raw material mixture comprising silicon nitride, silicon, an aluminium compound, a calcium compound, and a europium compound,

wherein the nitride fluorescent material has a composition represented by formula (I):

Sr_sCa_tAl_uSi_vN_w;

Eu 

 

(I)

wherein s, t, u, v, and w respectively satisfy 0≤

s<

1, 0<

t≤

1, s+t≤

1, 0.9≤

u≤

1.1, 0.9≤

v≤

1.1, and 2.5≤

w≤

3.5, and

wherein a content of silicon is from 30% by weight to 80% by weight relative to the total amount of silicon nitride and silicon in the raw material mixture.

2. The method according to claim 1, wherein the aluminium compound comprises aluminium nitride.

3. The method according to claim 1, wherein the calcium compound comprises calcium nitride.

4. The method according to claim 1, wherein the europium compound comprises europium oxide.

5. The method according to claim 1, wherein the raw material mixture is heat-treated at 1200°

C. or more.

6. The method according to claim 1, wherein the raw material mixture is heat-treated at from 1900°

C. to 2050°

C.

7. The method according to claim 1, wherein content of oxygen atom contained in the silicon nitride is from 0.3% by weight to less than 2% by weight.

8. The method according to claim 1, wherein the nitride fluorescent material has a specific surface area by Brunauer-Emmett-Teller (BET) method of from 0.05 m²/g to less than 0.3 m²/g.

9. The method according to claim 1, wherein the nitride fluorescent material has an average particle diameter of from 15 μ

m to 30 μ

m.

10. The method according to claim 1, wherein the nitride fluorescent material has a specific surface area by Brunauer-Emmett-Teller (BET) method of from 0.1 m²/g to 0.16 m²/g, and the nitride fluorescent material has an average particle diameter of from 20 μ

m to 30 μ

m.

11. The method according to claim 1, wherein the nitride fluorescent material has a specific surface area by Brunauer-Emmett-Teller (BET) method of from 0.1 m²/g to 0.15 m²/g, and the nitride fluorescent material has an average particle diameter of from 20 μ

m to 30 μ

m.