Light emitting device

• US 9,491,813 B2
• Filed: 03/15/2013
• Issued: 11/08/2016
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Tanda, Yuichiro, Matsushita, Toshio
• Primary Examiner(s): GRAMLING, SEAN P
• Application Number:
  US13/831,797
• Publication Number:
  US 20130200778A1
• Time in Patent Office: 1,334 Days
• US Class Current: 1/1
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/235 Details of bases or caps, i.e. the parts that connect the light source to a fitting; Arrangement of components within bases or caps F21K9/238 takes precedence
• CPC Class Codes: F21V 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 19/006 of point-like light sources, e.g. incandescent or halogen lamps, with screw-threaded or bayonet base of sources having contact pins, wires or blades F21V19/0005; of LEDs or sources mounted on printed-circuit board F21V19/001
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21V 31/005 Sealing arrangements therefor
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: F21V 9/32 characterised by the arrangement of the photoluminescent material
• CPC Class Codes: F21V 9/38 Combination of two or more photoluminescent elements of different materials
• CPC Class Codes: F21Y 2101/00 Point-like light sources
• CPC Class Codes: F21Y 2109/00 Light sources with light-generating elements disposed on transparent or translucent supports or substrates
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48095 Kinked
• 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 25/0753 the devices being arranged next to each other
• 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 2924/01004 : Beryllium [Be]
• CPC Class Codes: H01L 2924/0102 : Calcium [Ca]
• CPC Class Codes: H01L 2924/01063 : Europium [Eu]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 33/501 : characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/505 : characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/507 : the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• 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 33/54 : having a particular shape
• 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
• CPC Class Codes: H05B 33/04 : Sealing arrangements , e.g. against humidity

Abstract

A light emitting device includes a board, a light emitting element, and a transparent member. The light emitting element is mounted on the board. The transparent member seals the light emitting element. The transparent member is disposed around a periphery of the board and the light emitting element. The transparent member comprises a phosphor therein.

Claims

1. A light emitting device comprising:

a board having a first surface on a first surface side thereof and a second surface on a second surface side thereof, the second surface being an opposite side to the first surface;

a light emitting element mounted on the first surface of the board;

a first transparent member that seals the light emitting element;

a second transparent member disposed around a periphery of the first transparent member and continuously extending around both the first surface side and the second surface side of the board to continuously encapsulate the board; and

a pair of plates penetrating the second transparent member, one plate of the pair of plates longitudinally extending in a first direction and the other plate of the pair of plates, longitudinally extending in an opposite direction to the first direction,

wherein the second transparent member comprises a phosphor therein,

wherein the second transparent member is arranged to cover an edge surface of the board which is formed along a thickness of the board,

wherein the board is configured to be transparent so that a light emitted from the light emitting element on the first surface of the board forwards outside of the light emitting device through the second surface of the board,

wherein the second transparent member is elongated and longitudinally extends along an elongated direction, and

wherein each of the plates is continuously extended in the elongated direction from inside of the first transparent member to outside of the second transparent member.

2. The light emitting device according to claim 1, wherein the phosphor comprises a YAG group phosphor.

3. The light emitting device according to claim 1, wherein the light emitting element is plural.

4. The light emitting device according to claim 3, wherein the plurality of light emitting elements are electrically connected in series.

5. The light emitting device according to claim 1, wherein the light emitting element is so configured that a main peak light emission wavelength of the light emitting element is varied within a range between 420 nm and 490 nm.

6. The light emitting device according to claim 1, further comprising a transparent bulb which encloses the board and the light emitting element.

7. The light emitting device according to claim 6, further comprising a support lead which is electrically connected to the light emitting element,

wherein the board is fixed by the support lead inside the transparent bulb.

8. The light emitting device according to claim 1, wherein the second transparent member is formed in carved-shape on outer surface.

9. The light emitting device according to claim 1, wherein the light emitting element comprises nitride semiconductor made of In_xAl_yGa₁₋

x−

yN(0≦

x, 0≦

y, x+y≦

1).

10. The light emitting device according to claim 1, wherein the phosphor comprises CaSi₂O₂N₂:

Eu or SrSi₂O₂N₂;

Eu.

11. The light emitting device according to claim 1, wherein the phosphor comprises(Sr,Ca)₅(PO₄)₃Cl:

Eu.

12. The light emitting, device according to claim 1, wherein the phosphor comprises (Ca,Sr)₂Si₅N₈:

Eu.

13. The light emitting device according to claim 1, wherein an average particle size of the phosphor is 3 μ

m or more.

14. The light emitting device according to claim 9, wherein the phosphor comprises a YAG group phosphor.

15. The light emitting device according to claim 9, wherein the phosphor comprises CaSi₂O₂N₂:

Eu or SrSi₂O₂N₂;

Eu.

16. The light emitting device according to claim 9, wherein the phosphor comprises (Ca,Sr)₂Si₅N₈:

Eu.

17. The light emitting device according to claim 1, wherein the phosphor is capable of converting light emitted from the light emitting element into light with a different wavelength such that the converted light with the different wavelength is radiated along a first direction from the first surface of the board to an outer periphery of the second transparent member, and along a second direction from the second surface of the board to the outer periphery of the second transparent member.

18. The light emitting device according to claim 1, wherein the second transparent member is formed to have a round-shaped outer surface.

19. The light emitting device according to claim 1, wherein the second transparent member is formed to have a rectangular-parallelpiped shaped outer surface.

20. The light emitting device according to claim 1, wherein the second transparent member is disposed around an entire outer periphery of the first transparent member.

21. The light emitting device according to claim 1, wherein the second transparent member is disposed around and is directly in contact with an entire outer periphery of the first transparent member.

22. The light emitting device according to claim 1 wherein the board has a transmittance of 70% or more.

23. The light emitting device according to claim 1, wherein the board is configured to be transparent so that the light emitted from the light emitting element on the first surface of the board forwards outside of the light emitting device through a substantial portion of the second surface of the board.

24. The light emitting device according to claim 1, wherein the light emitting element includes semiconductor elements and an insulating surface provided between the semiconductor elements and the first surface of the board on which the light emitting element is mounted.

25. The light emitting device according to claim 1, wherein the light emitting element includes a semiconductor layer on an insulating substrate, the insulating substrate being provided between the semiconductor layer and the first surface of the board on which the light emitting element is mounted.

26. The light emitting device according to claim 25, wherein the insulating substrate is a sapphire substrate.

27. The light emitting device according to claim 1, wherein the light emitting device is further configured to emit the light from the light emitting element in a direction outwardly away from the first surface of the board.

28. The light emitting device according to claim 1, wherein the second transparent member directly contacts the second surface of the board.

29. The light emitting device according to claim 1, wherein the light emitting element comprises a growth substrate that is made by a sapphire substrate.

30. The light emitting device according to claim 1, wherein the first transparent member has a substantially flat surface thereon.

31. The light emitting device according to claim 1, wherein a plurality of the light emitting elements is provided between the pair of plates in a substantially linear arrangement on the board.

32. A light emitting device comprising:

a board having a first surface on a first surface side thereof and a second surface on a second surface side thereof, the second surface being an opposite side to the first surface;

a light emitting element mounted on the first surface side of the board;

a first transparent member that seals the light emitting element;

a second transparent member disposed around a periphery of the first transparent member and continuously extending around both the first surface side and the second surface side of the board to continuously encapsulate the board; and

a pair of plates penetrating the second transparent member, one plate of the pair of plates longitudinally extending in a first direction and the other plate of the pair of plates longitudinally extending in an opposite direction to the first direction,

wherein the second transparent member comprises a phosphor therein,

wherein the light emitting element is mounted on the first surface of the board and no light emitting element is mounted on the second surface of the board,

wherein the board is configured to be transparent so that a light emitted from the light emitting element on the first surface of the board forwards outside of the light emitting device through the second surface of the board,

wherein the second surface side of the transparent board does not have a light emitting element,

wherein the second transparent member is elongated and longitudinally extends along an elongated direction, and

wherein each of the plates is continuously extended in the elongated direction from inside of the first transparent member to outside of the second transparent member.

33. The light emitting device according to claim 32, wherein the second transparent member is attached to the second surface of the board.

34. The light emitting device according to claim 32, wherein the board is configured to be transparent so that a light emitted from the light emitting element on the first surface of the board forwards outside of the light emitting device through the second surface of the board.

35. The light emitting device according to claim 32, wherein a peripheral of the board is covered with the second transparent member in the manner that a flange of the board is non-exposed.

36. The light emitting device according to claim 32, wherein the second transparent member is arranged to cover an edge surface of the board which is formed along a thickness of the board.

37. The light emitting device according to claim 32, wherein the light emitting device is further configured to emit the light from the light emitting element in a direction outwardly away from the first surface side of the board.

38. The light emitting device according to claim 32, wherein the second transparent member directly contacts the second surface of the board.

39. A light emitting device comprising:

a board longitudinally extending in a first direction and having a first surface on a first surface side thereof and a second surface on a second surface side thereof, the second surface being an opposite side to the first surface;

a light emitting element mounted on the first surface side of the board;

a first transparent member that seals the light emitting element;

a second transparent member disposed around a periphery of the first transparent member and continuously extending around both the first surface side and the second surface side of the board to continuously encapsulate the board;

a wavelength conversion member which is disposed on the second transparent member and includes a phosphor therein; and

a pair of plates penetrating the second transparent member, one plate of the pair of plates longitudinally extending in the first direction and the other plate of the pair of plates longitudinally extending in an opposite direction to the first direction,

wherein the wavelength conversion member is disposed around and is directly in contact with an entire outer periphery of the second transparent member,

wherein the board is configured to be transparent so that a light emitted from the light emitting element on the first surface side of the board forwards outside of the light emitting device through the second surface of the board,

wherein the second surface side of the transparent board does not have a light emitting element,

wherein the second transparent member is elongated and longitudinally extends along an elongated direction, and

wherein each of the plates is continuously extended in the elongated direction from inside of the first transparent member to outside of the second transparent member.

40. The light emitting device according to claim 39, wherein the second transparent member is attached to the second surface of the board.

41. The light emitting device according to claim 39, wherein the board is configured to be transparent so that a light emitted from the light emitting element on the first surface of the board forwards outside of the light emitting device through the second surface of the board.

42. The light emitting device according, to claim 39, wherein the wavelength conversion member is separately disposed on the second transparent member.

43. The light emitting device according to claim 42, wherein the wavelength conversion member is disposed all around the entire outer periphery of the second transparent member.

44. The light emitting device according to claim 39, wherein the wavelength conversion member is disposed all around the entire outer periphery of the second transparent member.

45. The light emitting device according to claim 39, wherein each of the plates is extended substantially flat.

46. The light emitting device according to claim 39, wherein the second transparent member directly contacts the second surface of the board.

47. The light emitting device according to claim 39,

wherein the pair of plates is aligned coaxially, and

wherein the pair of plates both protrude from the second transparent member.