LED package with encapsulant having planar surfaces

• US 9,865,780 B2
• Filed: 03/18/2015
• Issued: 01/09/2018
• Est. Priority Date: 06/11/2012
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Lowes, Theodore, Tarsa, Eric, Heikman, Sten, Keller, Bernd, Reiherzer, Jesse, Benjamin, Hormoz
• Primary Examiner(s): Alavi, Ali
• Application Number:
  US14/661,874
• Publication Number:
  US 20150194580A1
• Time in Patent Office: 1,028 Days
• CPC Class Codes: F21V 9/00 Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters coloured shades F21V1/00; elements characterised by cooling arrangements F21V29/502
• CPC Class Codes: H01L 2224/48091 Arched
• 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 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

LED packages are disclosed that are compact and efficiently emit light, and can comprise encapsulants with planar surfaces that refract and/or reflect light within the package encapsulant. The packages can also comprise a submount with one or more LEDs, and a blanket conversion material layer on the one or more LEDs and the submount. The encapsulant can be on the submount, over the LEDs, and light reflected within the encapsulant will reach the conversion material, where it will be absorbed and emitted omnidirectionally. This allows for reflected light to now escape from the encapsulant. This allows for efficient emission and a broader emission profile, for example when compared to conventional packages with hemispheric encapsulants or lenses. In certain embodiments, the LED package provides a higher chip area to LED package area ratio. By using an encapsulant with planar surfaces, the LED package can provide unique dimensional relationships between the various features and the LED package ratios, enabling more flexibility in using the packages in different applications.

Claims

1. A lighting package, comprising:

a solid state light source on a submount;

a wavelength conversion material layer covering less than all of said solid state light source or less than all of the top surface of said submount;

an encapsulant over said submount, said encapsulant having one or more planar surfaces, wherein said planar surfaces cause total internal reflection (TIR) of at least some light from said light source.

2. The lighting package of claim 1, wherein said encapsulant comprises a planar top surface and planar side surfaces.

3. The lighting package of claim 1, wherein said encapsulant comprises a horizontal planar surface and a vertical planar surface.

4. The lighting package of claim 1, wherein said light source comprises a single LED.

5. The lighting package of claim 1, wherein said light source comprising multiple LED chips.

6. The lighting package of claim 5, wherein said LED chips are connected in series, in parallel, or in a series and parallel combination.

7. The lighting package of claim 1, wherein said encapsulant shape is from the group comprising cubic, prismatic, cylindrical, triangle, pentagon, hexagon and octagon.

8. The lighting package of claim 1, wherein said encapsulant comprises a horizontal surface and vertical surfaces numbering in the range of 3 to 12.

9. The lighting package of claim 1, wherein said one or more planar surfaces comprise features having a root mean square (RMS) size greater than the wavelength of light emitting from said LED light source.

10. The lighting package of claim 1, wherein the ratio of the footprint of said submount to the footprint of said one or more LEDs is in the range of just over 1 to approximately 20.

11. The lighting package of claim 1, wherein said submount has a footprint ratio of approximately 1 by 1, with a corresponding height ratio in the range of approximately 0.5 to 5.

12. The lighting package of claim 1, wherein said wavelength conversion material layer comprises a combination of red, green and yellow phosphors.

13. A lighting package, comprising:

a solid state light source on a submount;

a wavelength conversion material layer covering at least a portion of said solid state light source and/or at least a portion of the top surface of said submount;

an encapsulant over said submount, said encapsulant having two or more sets of opposing planar surfaces reflecting at least some light from said light source.

14. A lighting package, comprising:

a solid state light source on a submount;

a wavelength conversion material layer covering at least a portion of said solid state light source and/or at least a portion of the top surface of said submount;

an encapsulant over said submount, said encapsulant having flat top reflecting at least some light from said light source.

15. A lighting package, comprising:

an array of interconnected solid state light sources on a submount;

a wavelength conversion material layer covering one or more of said solid state light sources;

an encapsulant over said submount, said encapsulant having one or more planar surfaces, wherein said planar surfaces cause total internal reflection (TIR) of at least some light from said light source.

16. The lighting package of claim 15, wherein said LED chips are connected in series, in parallel, or in a series and parallel combination.

17. The lighting package of claim 15, wherein said conversion material layer covers at least a portion of the top surface of said submount.

18. The lighting package of claim 15, wherein at least two of said solid state light sources emit difference colors of light.

19. A lighting package, comprising:

a solid state light source on a submount;

a wavelength conversion material layer covering less than all of said solid state light source and/or less than all of the top surface of said submount, wherein said conversion material layer comprises a single phosphor or blend of a plurality of phosphors;

an encapsulant over said submount, said encapsulant having one or more planar surfaces, wherein only a portion of light from said light source passes out of said encapsulant on its first pass.

20. The lighting package of claim 19, wherein said conversion material layer comprises red, yellow and green emitting phosphors.