Light emitting diodes, components and related methods

• US 10,431,568 B2
• Filed: 09/13/2016
• Issued: 10/01/2019
• Est. Priority Date: 12/18/2014
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Gould, Troy, Blakely, Colin Kelly, Damborsky, Kyle, Reiherzer, Jesse Colin
• Primary Examiner(s): Hargrove, Frederick B
• Application Number:
  US15/264,547
• Publication Number:
  US 20170069606A1
• Time in Patent Office: 1,113 Days
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49113 the connectors connecting different bonding areas on the semiconductor or solid-state body to a common bonding area outside the body, e.g. converging wires
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of 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 2924/00014 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 2924/181 Encapsulation
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• 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 33/56 : Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/60 : Reflective elements

Abstract

Light emitting diode (LED) devices, components and systems are provided. LED devices include a submount with a plurality of LEDs disposed thereon. The LEDs mounted on a submount can be spaced apart at predetermined dimensions to control the gaps between each of the plurality of LEDs. By controlling the gaps between LEDs the optical output from the LED device can be optimized, including improving emission and/or color uniformity, minimizing or eliminating deadspots in the light emission, and/or minimizing or eliminating an optical cross. A phosphor layer can be disposed on the plurality of LEDs and between the LEDs in the gaps therebetween.

Claims

1. A light emitting diode (LED) device comprising:

a submount comprising an upper surface and a bottom surface;

a plurality of LEDs disposed on the upper surface of the submount, the plurality of LEDs each comprising an upper surface of a diode and one or more sides, the LEDs being spaced apart with a gap between the LEDs;

an encapsulant comprising an upper curved surface and one or more planar side surfaces, the upper curved surface having a radius curvature that is greater than half a length or width of the submount, wherein the one or more planar side surfaces comprise truncated sections of the upper curved surface so that the encapsulant does not overhang an outermost edge of the submount, at least a portion of each of the one or more planar side surfaces extending to a respective outermost edge of the upper surface of the submount; and

a phosphor layer disposed on the upper surface of the diodes, on one or more sides of the plurality of LEDs and in the gap between the LEDs,

wherein the gap between the LEDs ranges from about 1 to about 300 micrometers (μ

m),

wherein a ratio of a particle size of phosphor in the gap to a width of the gap between the LEDs is approximately 30% to approximately 75%,

wherein the device, based on the gap between the LEDs and the ratio of the particle size of phosphor in the gap to the width of the gap, is configured to produce an emission pattern devoid of a deadspot.

2. The device of claim 1, wherein the LEDs comprise LED chips.

3. The device of claim 1, wherein the gap between the LEDs ranges from about 1 μ

m to about 80 μ

m.

4. The device of claim 1, wherein the plurality of LEDs comprise at least four LEDs.

5. The device of claim 1, wherein the phosphor layer is also disposed on the upper surface of the submount.

6. The device of claim 5, wherein the phosphor layer substantially uniformly covers the upper surface and one or more sides of the plurality of LEDs and the upper surface of the submount.

7. The device of claim 1, wherein all sides of the LEDs are covered with the phosphor layer.

8. The device of claim 1, wherein the device is configured to emit light from the upper surface and all sides of the LEDs.

9. The device of claim 1, further comprising one or more electrically conductive contacts disposed on the bottom surface of the submount.

10. The device of claim 1, wherein a ratio of the upper surface of the diodes to the upper surface of the submount is greater than 0.18.

11. A light emitting diode (LED) device comprising:

a submount comprising an upper surface and a bottom surface;

at least four LEDs disposed on the upper surface of the submount, the at least four LEDs each comprising an upper surface of a diode and one or more sides, each of the at least four LEDs spaced apart with a gap therebetween; and

an encapsulant comprising an upper curved surface and one or more planar side surfaces, the upper curved surface having a radius curvature that is greater than half a length or width of the submount, wherein the one or more planar side surfaces comprise truncated sections of the upper curved surface so that the encapsulant does not overhang an outermost edge of the submount, at least a portion of each of the one or more planar side surfaces extending to a respective outermost edge of the upper surface of the submount;

a phosphor layer disposed over the upper surface of the diodes of the at least four LEDs and filling in the gap therebetween,

wherein a ratio of a particle size of phosphor in the gap to a width of the gap between the LEDs is approximately 30% to approximately 75%,

wherein the LED device, based on the gap between the LEDs and the ratio of the particle size of phosphor in the gap to the width of the gap, is configured to produce an emission pattern devoid of a deadspot, and

wherein the phosphor layer comprises a high density phosphor, wherein the high density phosphor comprises a ratio of phosphor to binder of about 2 to 1 or greater.

12. The device of claim 11, wherein the device is configured to produce an emission pattern devoid of an optical cross.

13. The device of claim 11, wherein the gap between the LEDs ranges from about 1 μ

m to about 80 μ

m.

14. The device of claim 11, wherein the gap between the LEDs is greater than a particle size of phosphor in the phosphor layer.

15. The device of claim 11, wherein the phosphor layer is also disposed on the upper surface of the submount.

16. The device of claim 11, wherein the LEDs each comprise an upper surface and four sides, wherein the phosphor layer is disposed on each of the upper surface and four sides of all LEDs.

17. The device of claim 16, wherein the device is configured to emit light from the upper surface and all sides of the LEDs.

18. The device of claim 11, wherein a ratio of the upper surface of the diodes to the upper surface of the submount is greater than 0.18.

19. A light emitting diode (LED) device comprising:

a submount comprising an upper surface and a bottom surface;

a plurality of LEDs disposed on the upper surface of the submount, the LEDs being spaced apart with a gap between the LEDs;

an encapsulant comprising an upper curved surface and one or more planar side surfaces, the upper curved surface having a radius curvature that is greater than half a length or width of the submount, wherein the one or more planar side surfaces comprise truncated sections of the upper curved surface so that the encapsulant does not overhang an outermost edge of the submount, at least a portion of each of the one or more planar side surfaces extending to a respective outermost edge of the upper surface of the submount; and

phosphor disposed in and filling the gap between the LEDs up to at least an upper surface of the LEDs,

wherein the gap between the LEDs is substantially similar to the particle size of the phosphor,

wherein the phosphor layer comprises a high density phosphor, wherein the high density phosphor comprises a ratio of phosphor to binder of about 2 to 1 or greater.

20. The device of claim 19, wherein the LEDs comprise LED chips.

21. The device of claim 19, further comprising phosphor disposed on the upper surface and one or more sides of the plurality of LEDs.

22. The device of claim 19, wherein phosphor on the upper surface and sides of the one or more LEDs comprises one or more phosphor colors.

23. The device of claim 19, wherein phosphor in the gap between the LEDs comprises only a single phosphor color.

24. The device of claim 19, wherein phosphor in the gap between the LEDs comprises one or more phosphor colors.

25. The device of claim 19, comprising a plurality of gaps between the LEDs and wherein the gaps differ in width.

26. The device of claim 19, wherein the gap between the LEDs ranges from about 1 μ

m to about 80 μ

m.

27. The device of claim 19, wherein a ratio of the upper surface of the diodes to the upper surface of the submount is greater than 0.18.