LIGHT EMITTING DEVICE INCLUDING LIGHT EMITTING ELEMENT WITH PHOSPHOR

• US 20160079484A1
• Filed: 09/14/2015
• Published: 03/17/2016
• Est. Priority Date: 09/16/2014
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Hosokawa, Shoji, KURAMOTO, Daiki, Nakata, Kenji, Bando, Atsushi
• Granted Patent: US 9,831,396 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 23/29 characterised by the material , e.g. carbon interlayer dielectrics H01L23/5329
• CPC Class Codes: H01L 23/295 containing a filler H01L23/296 takes precedence
• CPC Class Codes: H01L 2924/01015 Phosphorus [P]
• CPC Class Codes: H01L 2924/0106 Neodymium [Nd]
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/186 Material
• CPC Class Codes: H01L 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: H01L 33/52 Encapsulations
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin

Abstract

A light emitting device includes a light emitting element, a molded member, and a sealing member. The light emitting element is arranged on or above the molded member. The sealing member covers the light emitting element. The sealing member contains a phosphor, and a filler material. The phosphor can be excited by light of the light emitting element, and emit luminescent radiation. The filler material contains neodymium hydroxide, neodymium aluminate or neodymium silicate. The filler material absorbs a part of the spectrum of the mixed light of the light emitting element and the phosphor so that the other parts of the spectrum of this mixed light are extracted from the light emitting device.

Claims

1. A light emitting device comprising:

a light emitting element;

a molded member that holds said light emitting element; and

a sealing member that covers said light emitting element, the sealing member containing a phosphor that can be excited by light of said light emitting element and emit luminescent radiation, and a filler material that contains neodymium hydroxide, neodymium aluminate or neodymium silicate.

2. The light emitting device according to claim 1, wherein said filler material contains neodymium hydroxide, wherein the neodymium hydroxide is Nd(OH)₃ or NdO₂H.

3. The light emitting device according to claim 1, wherein said filler material contains neodymium aluminate or neodymium silicate, wherein the neodymium aluminate or neodymium silicate is represented by a general formula Nd_xM_yO_z where M is Si or Al, and x, y and z satisfy 1≦

x≦

10, 1≦

y≦

15, and 3≦

z≦

45, respectively.

4. The light emitting device according to claim 1, wherein said filler material contains neodymium aluminate or neodymium silicate, wherein the neodymium aluminate or neodymium silicate is at least one selected from the group consisting of NdAlO₃, Nd₂Si₂O₇, and Nd_9.83((Si, Al)O₄)₆O₂.

5. The light emitting device according to claim 1, wherein the reflectance of said filler material is not smaller than 50% and not greater than 65% in the wavelength range of not shorter than 575 nm and not longer than 605 nm.

6. The light emitting device according to claim 1, wherein the added amount of said filler material is not smaller than 0.01% by weight and not greater than 10% by weight of the material of said sealing member.

7. The light emitting device according to claim 1, wherein the mean particle diameter of said filler material is not smaller than 0.1 μ

m and not greater than 5 μ

m.

8. The light emitting device according to claim 1, wherein said phosphor contains at least one selected from the group consisting of (Lu, Y, Gd)₃(Al, Ga)₅O₁₂:

Ce, (Sr, Ca)AlSiN₃;

Eu, (Ba, Sr, Ca)₂SiO₄;

Eu, Ca₈MgSi₄O₁₆Cl₂;

Eu, and Sr₄Al₁₄O₂₅;

Eu.

9. The light emitting device according to claim 1, wherein said sealing member includes a first portion that covers said light emitting element and contains said phosphor, and a second portion that covers said first portion and contains said filler material.

10. The light emitting device according to claim 9, wherein said first portion is spaced at an interval away from said second portion.

11. The light emitting device according to claim 9, wherein said first or second portion is arranged on the upper surface of said molded member.

12. The light emitting device according to claim 1, wherein said phosphor and said filler material are mixed in said sealing member.

13. The light emitting device according to claim 1, wherein the material of the said sealing member is a light-transmissive resin.