Light emitting device and sealing material

• US 20050173708A1
• Filed: 02/04/2005
• Published: 08/11/2005
• Est. Priority Date: 02/06/2004
• Status: Active Grant

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Kato, Hideaki, Suehiro, Yoshinobu, Takano, Seiji
• Granted Patent: US 7,304,326 B2
• Time in Patent Office: Days
• US Class Current: 257/79
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond 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 2924/181 Encapsulation
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin

Abstract

A light emitting device has: a light emitting element; a conducting portion to supply power to the light emitting element; an element housing portion that houses the light emitting element therein; and a sealing material that seals the light emitting element housed in the element housing portion. The sealing material contains a transparent resin material and a transparent filler with a thermal expansion coefficient smaller than the transparent resin material, and the transparent filler has a refractive index nearly equal to the transparent resin material.

Claims

1. A light emitting device, comprising:

a light emitting element;

a conducting portion to supply power to the light emitting element;

an element housing portion that houses the light emitting element therein; and

a sealing material that seals the light emitting element housed in the element housing portion,

wherein the sealing material comprises a transparent resin material and a transparent filler with a thermal expansion coefficient smaller than the transparent resin material.

3. The light emitting device according to claim 1, wherein:

the transparent filler comprises a material with a light transparency proof against light and heat generated from the light emitting element.

4. The light emitting device according to claim 1, wherein:

the element housing portion is cone-shaped.

5. The light emitting device according to claim 1, wherein:

the element housing portion is made of a ceramic material.

6. The light emitting device according to claim 1, wherein:

the sealing material is made of epoxy resin.

7. The light emitting device according to claim 1, wherein:

the sealing material is made of silicone.

8. The light emitting device according to claim 1, wherein:

the transparent filler comprises glass.

9. The light emitting device according to claim 1, wherein:

the sealing material comprises a phosphor.

10. The light emitting device according to claim 1, wherein:

the sealing material comprises two layers contacted each other,

a first layer of the two layers comprises the light emitting device,

a second layer of the two layers comprises the phosphor, and

the first layer comprises the transparent filler more than the second layer.

14. The light emitting device according to claim 1, wherein:

the sealing material comprises a region with a concentration of the transparent filler higher than the other region in the vicinity of the light emitting element, and

the concentration of the transparent filler is 50% or more in volume ratio.

2. A light emitting device, comprising:

a light emitting element;

a conducting portion to supply power to the light emitting element;

an element housing portion that houses the light emitting element therein; and

a sealing material that seals the light emitting element housed in the element housing portion,

wherein the sealing material comprises a transparent resin material and a transparent filler with a thermal expansion coefficient smaller than the transparent resin material, and

the transparent filler has a refractive index nearly equal to the transparent resin material.

11. A light emitting device, comprising:

a light emitting element;

a conducting portion to supply power to the light emitting element;

an element housing portion that houses the light emitting element therein; and

a sealing material that seals the light emitting element housed in the element housing portion,

wherein the sealing material comprises a transparent resin material and a transparent filler with a thermal expansion coefficient smaller than the transparent resin material, and

the sealing material comprises a region with a concentration of the transparent filler higher than the other region in the vicinity of the light emitting element.

13. The light emitting device according to claim 11, wherein:

the transparent filler comprises a material with a light transparency proof against light and heat generated from the light emitting element.

15. The light emitting device according to claim 11, wherein:

the concentration of the transparent filler is 50% or more in volume ratio.

12. A light emitting device, comprising:

a light emitting element;

a conducting portion to supply power to the light emitting element;

an element housing portion that houses the light emitting element therein; and

a sealing material that seals the light emitting element housed in the element housing portion,

wherein the sealing material comprises a transparent resin material and a transparent filler with a thermal expansion coefficient smaller than the transparent resin material,

the transparent filler has a refractive index nearly equal to the transparent resin material, and

the sealing material comprises a region with a concentration of the transparent filler higher than the other region in the vicinity of the light emitting element.

16. The light emitting device according to claim 12, wherein:

the concentration of the transparent filler is 50% or more in volume ratio.

17. A sealing material, comprising:

a transparent resin material to seal a solid-state element; and

a transparent filler,

wherein the transparent filler has a refractive index nearly equal to the transparent resin material, and

the transparent filler comprises a material with a light transparency proof against light and heat generated from the solid-state element.

18. The sealing material according to claim 17, wherein:

the refractive index is within ±

0.025 to the refractive index of the transparent resin material.

19. The sealing material according to claim 17, wherein:

the refractive index is within ±

0.010 to the refractive index of the transparent resin material.

20. The sealing material according to claim 17, wherein:

the transparent filler comprises an average particle size of 10 to 100 micrometers.