Light emitting device and method of producing same

• US 20060054913A1
• Filed: 09/08/2005
• Published: 03/16/2006
• Est. Priority Date: 09/09/2004
• Status: Active Grant

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Suehiro, Yoshinobu, Hadame, Kunihiro
• Granted Patent: US 7,842,526 B2
• Time in Patent Office: Days
• US Class Current: 257/99
• CPC Class Codes: H01L 2224/0554 External layer
• CPC Class Codes: H01L 2224/0555 Shape
• CPC Class Codes: H01L 2224/0556 Disposition
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• 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 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/81 using a bump connector
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01045 : Rhodium [Rh]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01075 : Rhenium [Re]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 33/54 : having a particular shape
• CPC Class Codes: H01L 33/56 : Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/60 : Reflective elements

Abstract

A light emitting device having: a light emitting element; an electricity supply portion on which the light emitting element is mounted and which supplies electricity; and an inorganic sealing material for sealing the light emitting element. The inorganic sealing material has a tapered surface which becomes wider outward in a side surface direction with respect to a center axis of the light emitting element.

Claims

1. A light emitting device, comprising:

a light emitting element;

an electricity supply portion on which the light emitting element is mounted and which supplies electricity; and

an inorganic sealing material for sealing the light emitting element,

wherein the inorganic sealing material comprises a tapered surface that is wider outward in a side surface direction with respect to a center axis of the light emitting element.

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

the light emitting element is flip mounted on the electricity supply portion.

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

the electricity supply portion is a ceramic substrate formed with a conductive pattern for supplying electricity.

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

the inorganic sealing material is glass.

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

the inorganic sealing material is of a reversed-pyramid shape.

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

a vertical surface is formed on an upper surface of the tapered surface of the inorganic sealing material.

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

the tapered surface of the inorganic sealing material is provided with a member having high reflection coefficient with respect to light emitting spectrum of the light emitting element.

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

the member having high reflection coefficient with respect to the light emitting spectrum of the light emitting element has an index of refraction smaller than that of the inorganic sealing material.

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

the inorganic sealing material is provided at its light emitting surface with a transparent member including a phosphor.

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

the inorganic sealing material includes a phosphor.

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

the light emitting element comprises a plurality of light emitting elements.

12. A method of producing a light emitting device, comprising:

a first step of mounting a plurality of surface mounting type light emitting elements on an insulative substrate at predetermined distances from one another;

a second step of forming a glass sealing member with uniform thickness such as to cover the plurality of light emitting elements; and

a third step of cutting the substrate and the glass sealing member such that a tapered surface is formed around each of the plurality of light emitting elements.

13. The method of producing a light emitting device according to claim 12, wherein:

in the third step, the substrate and the glass sealing member are cut by a tapered blade having a cutting edge angle corresponding to an angle of the tapered surface.

14. The method of producing a light emitting device according to claim 12, wherein:

in the third step, the substrate and the glass sealing member are cut halfway by a first tapered blade having a cutting edge angle corresponding to the angle of the tapered surface and then, the glass sealing member is cut off by a second tapered blade having a blade width which is narrower than that of the first tapered blade until the glass sealing member is divided.

15. A light emitting device, comprising:

an LED element;

a sealing member made of glass for sealing the LED element;

a phosphor layer provided on the side of a light emitting surface of the sealing member; and

a cover provided on the sealing member for preventing radiation light of the LED element from being emitted from a region where the phosphor layer of the sealing member is not provided.

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

the cover comprises a reflection layer for reflecting the radiation light toward the phosphor layer side.

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

the reflection layer comprises a pigment-based white paint.

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

the reflection layer is formed on a reflection frame.

19. The light emitting device according to claim 18, wherein:

the reflection frame is formed with a reflection surface for optically controlling light emitted externally from the phosphor layer.

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

the phosphor layer and the cover are formed using two colors.

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

the LED element is a plurality of LED elements.

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

the LED element includes a p-type electrode comprising transparent conductive oxide.

23. A method of producing a light emitting device, comprising:

a sealing step of sealing an LED element mounted on a element-mounting portion with a sealing member comprising glass;

a phosphor layer forming step of forming a phosphor layer on the side of a light emitting surface of the sealing member; and

a step of forming a cover on the sealing member for preventing radiation light of the LED element from being emitted from a region where the phosphor layer of the sealing member is not provided.

24. The method of producing a light emitting device according to claim 23, wherein:

the sealing step includes a step of sealing a plurality of LED elements mounted on a common element-mounting portion with a common sealing member; and

the phosphor layer forming step includes a step of forming a common phosphor layer on the common sealing member.