Light emitting device with wavelength converting side coat

• US 10,043,952 B2
• Filed: 03/26/2013
• Issued: 08/07/2018
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Inventors: Vampola, Kenneth, Choi, Han Ho
• Primary Examiner(s): Dang, Trung Q
• Assistant Examiner(s): Reddington, Patricia
• Application Number:
  US14/388,979
• Publication Number:
  US 20150060917A1
• Time in Patent Office: 1,960 Days
• Field of Search: 257 98
• 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 2924/00014 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 2933/0041 relating to wavelength conversion elements
• 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 33/508 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 33/56 Materials, e.g. epoxy or silicone resin

Abstract

Embodiments of the invention include a semiconductor light emitting device, a first wavelength converting member disposed on a top surface of the semiconductor light emitting device, and a second wavelength converting member disposed on a side surface of the semiconductor light emitting device. The first and second wavelength converting members include different wavelength converting materials.

Claims

1. A structure comprising:

a semiconductor light emitting device;

a first wavelength converting member disposed on a top light-emitting surface of the semiconductor light emitting device, the first wavelength converting member comprising a first wavelength converting material and is no wider than the top light-emitting surface; and

a second wavelength converting member disposed on a side surface of the semiconductor light emitting device, the second wavelength converting member comprising a second wavelength converting material that is not over the top light-emitting surface, the first and second wavelength converting materials being different wavelength converting materials.

2. The structure of claim 1 wherein the first wavelength converting member comprises a prefabricated wavelength converting member.

3. The structure of claim 2 wherein the first wavelength converting member comprises a phosphor embedded in a transparent material.

4. The structure of claim 1 wherein the first wavelength converting member comprises a ceramic phosphor.

5. The structure of claim 1 wherein the second wavelength converting material comprises a powder phosphor disposed in a transparent matrix.

6. The structure of claim 1 wherein:

the first wavelength converting material emits green or yellow light; and

the second wavelength converting material emits red light.

7. The structure of claim 1, wherein the second wavelength converting member further comprises scattering particles.

19. The structure of claim 1 wherein the second wavelength converting member extends onto a side surface of the first wavelength converting member.

20. The structure of claim 1 wherein the second wavelength converting material can be excited by light emitted by the first wavelength converting material.

21. The structure of claim 1 wherein the semiconductor light emitting device further comprises electrical connections on a bottom surface of the semiconductor light emitting device.

8. A method comprising:

disposing a first wavelength converting material over a top light-emitting surface of a semiconductor light emitting device, the first wavelength converting material being confined to an area no wider than the top light-emitting surface; and

after disposing the first wavelength converting material over the top light-emitting surface of the semiconductor light emitting device, disposing a second wavelength converting material on a side surface of the semiconductor light emitting device, the second wavelength converting material not extending over the top light-emitting surface.

9. The method of claim 8 wherein disposing the first wavelength converting material comprises attaching a prefabricated wavelength converting member to the top light-emitting surface of the semiconductor light emitting device.

10. The method of claim 9 wherein the first wavelength converting material is a ceramic phosphor.

11. The method of claim 9 wherein the first wavelength converting material is a phosphor embedded in glass.

12. The method of claim 9 wherein the prefabricated wavelength converting member comprises a first region of wavelength converting material and a second region of transparent material.

13. The method of claim 12 wherein attaching the prefabricated wavelength converting member comprises attaching the prefabricated wavelength converting member such that the first region is disposed between the semiconductor light emitting device and the second region.

14. The method of claim 12 wherein attaching the prefabricated wavelength converting member comprises attaching the prefabricated wavelength converting member such that the second region is disposed between the semiconductor light emitting device and the first region.

15. The method of claim 8 wherein disposing the second wavelength converting material on the side surface of the semiconductor light emitting device comprises molding the second wavelength converting material.

16. The method of claim 8 wherein the first and second wavelength converting materials emit light of different colors.

17. The method of claim 8 wherein disposing of the second wavelength converting material on the side surface of the semiconductor light emitting device further disposes the second wavelength converting material on a side surface of the first wavelength converting material.

18. The method of claim 9 wherein disposing the second wavelength converting material comprises molding the second wavelength converting material on the side surface of the semiconductor light emitting device and on a side surface of the prefabricated wavelength converting member.

22. The method of claim 8 further comprising electrically connecting a mount to electrical connections that are on a bottom surface of the semiconductor light emitting device.