Light emitting devices for light emitting diodes (LEDs)

• US 8,564,000 B2
• Filed: 02/16/2011
• Issued: 10/22/2013
• Est. Priority Date: 11/22/2010
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Hussell, Christopher P., Andrews, Peter Scott, Reiherzer, Jesse Colin, Emerson, David T.
• Primary Examiner(s): LE, DUNG ANH
• Application Number:
  US13/028,972
• Publication Number:
  US 20120126255A1
• Time in Patent Office: 979 Days
• Field of Search: 257 12- 13, 257 98-100, 257431-433, 438 27- 28
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• 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 33/52 Encapsulations
• 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

Abstract

Light emitting devices for light emitting diodes (LEDs) are disclosed. In one embodiment a light emitting device can include a substrate, one or more LEDs disposed over the substrate, and the LEDs can include electrical connectors for connecting to an electrical element. A light emitting device can further include a retention material disposed over the substrate and the retention material can be disposed over at least a portion of the electrical connectors. The LEDs can be connected in a pattern that is non-linear.

Claims

1. A light emitting device comprising:

a substrate;

a plurality of light emitting diodes (LEDs) disposed over the substrate, the LEDs comprising electrical connectors, and wherein at least some of the LEDs are connected in a first pattern that is non-linear; and

a retention material disposed over the substrate, wherein the retention material is disposed over at least a portion of the electrical connectors.

2. The light emitting device of claim 1 wherein the retention material is dispensed on the substrate.

3. The light emitting device of claim 1 wherein an upper surface of the retention material opposite the substrate has a curved cross section.

4. The light emitting device of claim 1 further comprising at least one electrostatic discharge device (ESD) and wherein the ESD is at least partially covered by the retention material.

5. The light emitting device of claim 1 wherein at least some of the LEDs are arranged in a checkerboard configuration.

6. The light emitting device of claim 5 wherein the plurality of LEDs are disposed in a plurality of strings each comprising four or more LEDs.

7. The light emitting device of claim 6 wherein there are at least 14 LEDs disposed in each string and a total of at least 140 LEDs.

8. The light emitting device of claim 1 wherein the electrical connectors comprise wirebonds.

9. The light emitting device of claim 1 wherein the substrate comprises one or more intervening layers disposed between the retention material and the substrate.

32. The light emitting device of claim 1, wherein at least some of the LEDs are serially connected.

10. A light emitting device comprising:

a substrate;

at least one conductive trace electrically connected with the substrate;

an array of LEDs electrically connected with the at least one conductive trace, wherein the array of LEDs comprises at least one set of LEDs connected in a first pattern that is non-linear; and

a retention material disposed over the substrate, wherein the retention material is disposed about the array of LEDs.

11. The light emitting device of claim 10 wherein the retention material retains a fill material at least partially disposed over the array of LEDs.

12. The light emitting device of claim 11 wherein the fill material at least partially comprises a phosphor or other material for affecting a color of light emitted from the array of LEDs.

13. The light emitting device of claim 10 wherein the retention material is disposed over at least a portion of each of the at least one conductive trace and a solder mask, the solder mask at least partially disposed over a portion of the substrate.

14. The light emitting device of claim 10 wherein the retention material is disposed over at least a portion of the at least one conductive trace to which at least a first LED of the array of LEDs is electrically connected.

15. The light emitting device of claim 10 further comprising one or more attachment surfaces on an upper surface of substrate for electrically connecting the light emitting device to an external power source, wherein the attachment surfaces are disposed adjacent to the retention material.

16. The light emitting device of claim 15 wherein the attachment surfaces comprise solder contacts.

17. The light emitting device of claim 10 wherein the substrate comprises one or more intervening layers disposed between the retention material and the substrate.

33. The light emitting device of claim 10, wherein the at least one set of LEDs are serially connected.

18. A light emitting device comprising:

a substrate comprising a metal core layer, a dielectric layer disposed over the core layer, and a metallic trace disposed over the dielectric layer;

two or more strings of light emitting diodes (LEDs) disposed over the substrate, each string comprising a plurality of LEDs electrical connected in series; and

a circular shaped retention material disposed over the substrate and at least partially around the two or more strings of LEDs.

19. A light emitting device, comprising:

a substrate;

a first plurality of light emitting diodes (LEDs) disposed over the substrate in a first pattern;

a second plurality of LEDs disposed over the substrate in a second pattern; and

wherein the first pattern is different from the second pattern.

20. The light emitting device of claim 19 further comprising a retention material disposed on the substrate at least partially disposed around the first and second patterns.

21. The light emitting device of claim 20, wherein the LEDs comprise electrical connectors and wherein the retention material is disposed over at least a portion of the electrical connectors.

22. The light emitting device of claim 21 wherein the electrical connectors comprise wirebonds.

23. The light emitting device of claim 19, wherein at least one of the first or second pluralities of LEDs comprises LEDs electrically connected in series.

24. The light emitting device of claim 19, wherein the first and second patterns comprise at least two of the following arrangements:

(i) a checkerboard arrangement;

(ii) a straight line arrangement; and

(iii) a grid arrangement wherein the LEDs are substantially aligned in at least two directions.

25. The light emitting device of claim 24, wherein the first and second patterns comprise a combination of any two of the checkerboard, straight line, or grid arrangements.

26. The light emitting device of claim 19 further comprising a third plurality of LEDs disposed over the substrate in a third pattern that is different from the first and second patterns.

27. The light emitting device of claim 26, wherein the first plurality comprises a first set of LEDs, the second plurality comprises a second set of LEDs, and the third plurality comprises a third set of LEDs, and wherein each set of LEDs is disposed over the substrate.

28. The light emitting device of claim 19, wherein the LEDs of at least one of the first and second plurality of LEDs are arranged in different arrangements over the substrate.

29. The light emitting device of claim 28, wherein the first plurality of LEDs comprise LEDs arranged in parallel with LEDs of the second plurality of LEDs.

30. The light emitting device of claim 19, wherein the first plurality of LEDs comprises rectangular LEDs in a first orientation and the second plurality of LEDs comprises rectangular LEDs in a second orientation different from the first orientation.

31. The light emitting device of claim 19, wherein at least a first LED of the first plurality of LEDs comprises a rectangular LED in a first orientation and at least a second LED of the first plurality of LEDs comprises a rectangular LED in a second orientation different from the first orientation.