LED assembly with an LED and adjacent lens and method of making same

• US 7,737,636 B2
• Filed: 05/07/2007
• Issued: 06/15/2010
• Est. Priority Date: 11/09/2006
• Status: Active Grant

• Current Assignee: Intematix Corporation
• Original Assignee: Intematix Corporation
• Inventors: Dong, Yi, Li, Yi-Qun, Shan, Wei
• Primary Examiner(s): Williams; Joseph L
• Application Number:
  US11/800,977
• Publication Number:
  US 20080111141A1
• Time in Patent Office: 1,135 Days
• Field of Search: 313/512, 362/545
• US Class Current: 313/512
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/54 having a particular shape

Abstract

An LED assembly having an LED and a lens disposed adjacent to a light emitting surface of the LED. The area of cross-section of the lens projected onto the light emitting surface of the LED is substantially equal to or less than the area of the LED'"'"'s light emitting surface. The light emitting device can comprise an array of LEDs and an array of lenses, in which at least one lens is associated with each member of the LED array and wherein the area of a cross-section of each lens projected onto the light emitting surface of its associated LED is substantially equal to or less than the area of the LED'"'"'s light emitting surface.

Claims

1. An LED assembly comprising:

an LED chip and a lens disposed adjacent to a light emitting surface of the LED chip;

wherein the area of a cross-section of the lens is substantially equal to or less than the area of the LED chips light emitting surface.

2. The LED assembly of claim 1, and further comprising a phosphor encapsulated within a transparent material, the transparent material surrounding at least a portion of the light emitting surface of the LED chip.

3. The LED assembly of claim 1, and further comprising a phosphor layer disposed between the lens and at least a portion of the LED chips light emitting surface.

4. An LED assembly comprising:

at least two lenses disposed adjacent to a light emitting surface of an LED chip;

wherein the sum of the areas of the cross-sections of the at least two lenses is substantially equal to or less than the area of the LED chips light emitting surface.

5. The LED assembly of claim 4, and further comprising a phosphor encapsulated within a transparent material, the transparent material surrounding at least a portion of the light emitting surface of the LED chip.

6. The LED assembly of claim 4, and further comprising a phosphor layer disposed between the at least two lenses and at least a portion of the LED chips light emitting surface.

14. The LED assembly of claim 4, wherein each lens has dimensions in a range ˜

10 nm to 100 μ

m.

7. A light emitting device comprising:

an array of LED chips and an array of lenses, wherein there is at least one lens associated with each LED chip of the array and wherein the area of a cross-section of each lens is substantially equal to or less than the area of the associated LED chips light emitting surface.

8. The light emitting device of claim 7, and further comprising a phosphor encapsulated within a transparent material, the transparent material surrounding at least a portion of the lens array.

9. The light emitting device of claim 7, and further comprising a phosphor layer disposed between at least one of the lenses of the lens array and at least one of the LED chips of the LED array.

10. A photonic device comprising:

an LED chip configured to emit radiation at a first wavelength from a light emitting surface;

a lens configured to optically focus radiation from the LED chip;

a phosphor positioned adjacent to the LED chip, the phosphor configured to absorb at least a portion of the radiation emitted by the LED chip and emit radiation at a second wavelength, wherein the area of a cross-section of the lens is substantially equal to or less than the area of the LED chips light emitting surface.

11. The photonic device of claim 10, wherein the phosphor is encapsulated within a transparent material, the transparent material surrounding at least a portion of a light emitting surface of the LED chip.

12. The photonic device of claim 11, wherein the phosphor is disposed as a layer between the lens and at least a portion of the LED chips light emitting surface.

13. A method of fabricating an LED assembly, the method comprising:

a) dispensing a transparent lens material onto a substrate containing an LED chip array; and

b) molding the transparent lens material into a desired pattern of lenses to match the pattern of the LED chip array.

15. The method of claim 13, and comprising molding the lens material into the pattern of lenses by stamping the lens material with a stamp.

16. The method of claim 15, and further comprising, prior to removing the stamp, at least partially curing the lens material.

17. The method of claim 16, wherein the lens material is ultra violet curable and the stamp is substantially transparent to ultra violet radiation and comprising at least partially curing the lens material by irradiating the lens material through the stamp with ultra violet radiation.

18. The method of claim 15, wherein the lens material is thermally curable and comprising at least partially curing the lens material by heat treating the lens material.

19. The method of claim 15, wherein the stamp is configured such as to form windows in the lens material for providing electrical access to electrodes of the LED chip array.

20. The method of claim 19, and further comprising removing residual lens material from the electrodes by a process selected from the group consisting of:

etching, oxygen plasma etching and wet etching.

21. The method of claim 19, and further comprising, prior to depositing the lens material, providing a release agent substantially overlying the electrodes.

22. The method of claim 21, and further comprising processing the release agent and removing lens material from the electrodes using a lift-off process.

23. The method of claim 13, and further comprising, prior to dispensing the lens material on the LED chip array, depositing a phosphor layer over substantially the entire surface of the LED chip array.

24. The method of claim 23, wherein the stamp is configured such as to form windows in the lens material and phosphor for providing electrical access to electrodes of the LED chip array.

25. The method of claim 24, and further comprising removing residual lens material and phosphor from the electrodes by a process selected from the group consisting of:

etching, oxygen plasma etching and wet etching.

26. The method of claim 24, and further comprising, prior to depositing the phosphor, providing a release agent overlying the electrodes.

27. The method of claim 26, and further comprising processing the release agent and removing lens material and phosphor from the electrodes using a lift-off process.

28. The method of claim 13, and comprising, prior to dispensing the lens material, depositing a phosphor layer over substantially the entire surface of the LED chip array and patterning the phosphor so as to leave windows in the phosphor for providing electrical access to electrodes of the LED chip array.

34. The method according to claim 28, and further comprising dispensing a transparent lens material onto the substrate and molding the transparent lens material into a desired pattern of lenses to match the pattern of the LED chip array.

29. A method of fabricating an LED assembly, the method comprising:

a) dispensing a phosphor layer over substantially an entire surface of a substrate containing an LED chip array; and

b) patterning the phosphor such as to leave windows in the phosphor for providing electrical access to electrodes of the LED chip array.

30. The method according to claim 29, and comprising patterning the phosphor by stamping the phosphor with a stamp configured such as to form the windows.

31. The method of claim 30, and further comprising removing residual phosphor from the electrodes by a process selected from the group consisting of:

etching, oxygen plasma etching and wet etching.

32. The method of claim 30, and further comprising, prior to depositing the phosphor, providing a release agent substantially overlying the electrodes.

33. The method of claim 32, and further comprising processing the release agent and removing phosphor from the electrodes using a lift-off process.