LIGHT EMITTING DEVICE WITH WAVELENGTH CONVERTING SIDE COAT

• US 20150060917A1
• Filed: 03/26/2013
• Published: 03/05/2015
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Vampola, Kenneth, Choi, Han Ho
• Granted Patent: US 10,043,952 B2
• Time in Patent Office: Days
• US Class Current: 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 surface of the semiconductor

light emitting device, wherein the first wavelength converting member is no wider than the top surface; and

a second wavelength converting member disposed on a side surface of the semiconductor light emitting device, wherein the second wavelength converting member does not extend over the top surface;

wherein the first and second wavelength converting members comprise 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 member comprises a powder phosphor disposed in a transparent matrix.

6. The structure of claim 1 wherein:

the first wavelength converting member comprises a wavelength converting material

that emits green or yellow light; and

the second wavelength converting member comprises a wavelength converting material that emits red light.

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

8. A method comprising:

providing a semiconductor light emitting device;

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

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

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