Light emitting diode component

• US 20050239227A1
• Filed: 04/26/2004
• Published: 10/27/2005
• Est. Priority Date: 08/30/2002
• Status: Active Grant

• Current Assignee: General Electric Company, Consumer Lighting, LLC (d/b/a GE Lighting) (Savant Systems, LLC)
• Original Assignee: Gelcore (General Electric Company)
• Inventors: Radkov, Emil, Petroski, James T., Aanegola, Srinath K., Weaver, Stanton E. Jr.
• Granted Patent: US 7,224,000 B2
• Time in Patent Office: Days
• US Class Current: 438/26
• CPC Class Codes: H01L 2224/48091 Arched
• 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 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 33/52 Encapsulations
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A light emitting package (8, 8′, 8″, 208, 408) includes a printed circuit board (10, 10′, 10″, 210, 410) supporting at least one light emitting die (12, 12″, 14, 16, 212, 412). A light transmissive cover (60, 60′, 60″, 260, 460) is disposed over the at least one light emitting die. The cover has an open end defining a cover perimeter (62, 62′, 62″, 262, 462) connected with the printed circuit board. An inside surface of the cover together with the printed circuit board defines an interior volume (70, 70″, 270, 470) containing the at least one light emitting die. An encapsulant (76, 76″, 276, 278, 476) is disposed in the interior volume and covers at least the light emitting die.

Claims

1. A light emitting package comprising:

a printed circuit board supporting at least one light emitting die and having at least two electrical terminals, printed circuitry of the printed circuit board connecting the at least one light emitting die with the at least two electrical terminals to provide power thereto;

a light transmissive cover disposed over the at least one light emitting die but not over the at least two electrical terminals, the cover having an open end defining a cover perimeter connected with the printed circuit board, an inside surface of the cover together with the printed circuit board defining an interior volume containing the at least one light emitting die; and

an encapsulant disposed in the interior volume and covering at least the light emitting die.

2. The light emitting package as set forth in claim 1, wherein the at least one light emitting die and the electrical terminals are disposed on opposite sides of the printed circuit board.

3. The light emitting package as set forth in claim 1, wherein the printed circuit board is substantially planar.

4. The light emitting package as set forth in claim 3, wherein the printed circuit board includes at least one reflective well corresponding to the at least one light emitting die, each light emitting die being disposed inside of the corresponding reflective well.

5. The light emitting package as set forth in claim 1, wherein the encapsulant substantially fills the interior volume.

6. The light emitting package as set forth in claim 1, wherein at least two openings communicate with the interior volume, the openings being formed into at least one of:

(i) the printed circuit board, (ii) the light transmissive cover, and (iii) a connection between the cover perimeter and the printed circuit board.

7. The light emitting package as set forth in claim 6, wherein the openings are filled with one of:

(i) a portion of the encapsulant, and (ii) a filling material.

8. The light emitting package as set forth in claim 1, wherein the light transmissive cover is a glass cover.

9. The light emitting package as set forth in claim 8, further comprising:

a phosphor disposed on an inside surface of the cover.

10. The light emitting package as set forth in claim 9, further comprising:

an optical coating disposed between the phosphor and the inside surface of the cover.

11. The light emitting package as set forth in claim 8, wherein the encapsulant comprises:

a silicone encapsulant substantially filling the interior volume.

12. The light emitting package as set forth in claim 1, wherein the interior volume is substantially hermetically sealed by the connection between the cover perimeter and the printed circuit board.

13. The light emitting package as set forth in claim 1, wherein the encapsulant comprises:

a liquid or non-rigid semi-solid encapsulant contained in the interior volume by the connection of the cover perimeter and the printed circuit board.

14. The light emitting package as set forth in claim 1, further comprising:

an adhesive disposed between the cover perimeter and the printed circuit board to secure the cover perimeter and the printed circuit board.

15. The light emitting package as set forth in claim 1, wherein the printed circuit board includes a groove receiving the cover perimeter.

16. The light emitting package as set forth in claim 1, wherein the printed circuit board comprises:

a metal core printed circuit board providing heat sinking for the at least one light emitting die.

17. The light emitting package as set forth in claim 1, wherein the at least one light emitting die comprise:

a plurality of bare light emitting dice commonly encapsulated by the encapsulant and not including separate encapsulation.

18. The light emitting package as set forth in claim 1, further comprising:

a phosphor disposed on, in, or inside the light transmissive cover.

19. The light emitting package as set forth in claim 18, wherein the phosphor is disposed on an outside surface of the light transmissive cover.

20. The light emitting package as set forth in claim 18, wherein the phosphor is embedded in the light transmissive cover.

21. The light emitting package as set forth in claim 18, wherein the phosphor is distributed in a portion of the encapsulant distal from the at least one light emitting die and proximate to the light transmissive cover.

22. The light emitting package as set forth in claim 18, wherein:

the phosphor is disposed on the inside surface of the light transmissive cover; and

the encapsulant substantially fills the interior volume.

23. The light emitting package as set forth in claim 18, wherein:

the phosphor is disposed on the inside surface of the light transmissive cover; and

the encapsulant includes (i) a first portion covering the at least one light emitting die and (ii) a second portion covering the phosphor disposed on the inside surface of the light transmissive cover.

24. The light emitting package as set forth in claim 18, wherein:

a surface of the printed circuit board disposed inside the light transmissive cover is reflective for light emitted by the at least one light emitting die and for light emitted by the phosphor; and

a surface of the printed circuit board disposed outside the light transmissive cover is reflective for light emitted by the phosphor.

25. A light emitting package comprising:

at least one light emitting die;

a support on which the at least one light emitting die is disposed;

a glass cover disposed on the support over the at least one light emitting die, the glass cover and the support cooperatively defining an interior volume containing the at least one light emitting die; and

an encapsulant disposed in the interior volume and encapsulating the at least one light emitting die.

26. The light emitting package as set forth in claim 25, further comprising:

a phosphor disposed on, in, or inside the glass cover.

27. The light emitting package as set forth in claim 26, wherein the phosphor is disposed on an inside surface of the glass cover.

28. The light emitting package as set forth in claim 26, wherein the encapsulant substantially fills the interior volume.

29. The light emitting package as set forth in claim 25, further comprising:

an optical coating disposed on a surface of the glass cover, the optical coating reflecting or absorbing light produced by the at least one light emitting die; and

a phosphor disposed in the interior volume, the optical coating substantially transmitting light produced by the phosphor.

30. The light emitting package as set forth in claim 29, wherein the phosphor is disposed on the optical coating.

31. The light emitting package as set forth in claim 29, wherein the phosphor is disposed in a portion of the encapsulant distal from the at least one light emitting die and proximate to the glass cover.

32. The light emitting package as set forth in claim 25, wherein the glass cover is one of dome-shaped and tube-shaped.

33. The light emitting package as set forth in claim 25, wherein the support is a generally planar support and the glass cover includes a generally planar perimeter secured to the generally planar support.

34. The light emitting package as set forth in claim 25, wherein the glass cover includes a perimeter substantially hermetically sealed to the support.

35. A light emitting package comprising:

at least one light emitting die;

a support on which the at least one light emitting die is disposed;

a single-piece light transmissive cover disposed on the support over the at least one light emitting die, the single-piece cover and the support cooperatively defining a substantially closed interior volume containing the at least one light emitting die; and

an encapsulant disposed in the interior volume and encapsulating the at least one light emitting die.

36. The light emitting package as set forth in claim 35, wherein at least two openings communicate with the interior volume, the openings being formed into at least one of:

(i) the support, (ii) the light transmissive cover, and (iii) an interface between the light transmissive cover and the support.

37. The light emitting package as set forth in claim 35, wherein the encapsulant substantially fills the interior volume.

38. The light emitting package as set forth in claim 37, further comprising:

a phosphor disposed on, in, or inside the single-piece light transmissive cover.

39. The light emitting package as set forth in claim 37, wherein the encapsulant is at a pressure higher than atmospheric pressure.

40. The light emitting package as set forth in claim 37, wherein the encapsulant is one of a liquid encapsulant and a non-rigid semi-solid encapsulant.

41. The light emitting package as set forth in claim 35, wherein the support includes a reflective coating.

42. The light emitting package as set forth in claim 35, wherein the support is a printed circuit board including a heat sinking core.

43. The light emitting package as set forth in claim 35, wherein the single-piece light transmissive cover comprises:

an inorganic amorphous light transmissive cover.

44. A method for making a light emitting package, the method comprising:

electrically and mechanically connecting at least one light emitting die to a printed circuit board;

securing a light transmissive cover to the printed circuit board, the light transmissive cover covering the at least one light emitting die, the secured light transmissive cover and the printed circuit board cooperatively defining an interior volume; and

disposing an encapsulant in the interior volume.

45. The method for making a light emitting package as set forth in claim 44, further comprising:

disposing a phosphor on or in the light transmissive cover.

46. The method for making a light emitting package as set forth in claim 45, wherein the disposing of a phosphor comprises:

disposing the phosphor on an inside surface of the light transmissive cover using one of;

(i) electrostatic coating, (ii) slurry coating, and (iii) spray coating.

47. The method for making a light emitting package as set forth in claim 45, wherein the disposing of a phosphor comprises:

disposing an adhesive on a surface of the light transmissive cover;

applying a phosphor powder to the adhesive; and

hardening the adhesive.

48. The method for making a light emitting package as set forth in claim 47, wherein the adhesive is disposed on a concave inside surface of the light transmissive cover, and the applying of the phosphor powder comprises:

pouring the phosphor powder inside of the light transmissive cover.

49. The method for making a light emitting package as set forth in claim 47, wherein the adhesive is disposed on a convex outside surface of the light transmissive cover, and the applying of the phosphor powder comprises:

dipping the outside surface of the light transmissive cover into the phosphor powder.

50. The method for making a light emitting package as set forth in claim 44, wherein the disposing of an encapsulant comprises:

encapsulating the at least one light emitting die on the printed circuit board before the securing of the light transmissive cover.

51. The method for making a light emitting package as set forth in claim 44, wherein the disposing of an encapsulant comprises:

injecting the encapsulant into the interior volume after the securing of the light transmissive cover to the printed circuit board.

52. A method for disposing of a phosphor on a surface, the method comprising:

disposing an adhesive on the surface;

applying a phosphor powder to the adhesive; and

hardening the adhesive.

53. The method as set forth in claim 52, wherein the surface is a concave surface, the adhesive is disposed on the concave surface, and the applying of the phosphor powder comprises:

pouring the phosphor powder inside of the concave surface.

54. The method as set forth in claim 52, wherein the surface is a convex surface, the adhesive is disposed on the convex surface, and the applying of the phosphor powder comprises:

dipping the convex surface into the phosphor powder.