Light emitting device with molded wavelength converting layer

• US 8,771,577 B2
• Filed: 02/16/2010
• Issued: 07/08/2014
• Est. Priority Date: 02/16/2010
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Philips Lumileds Lighting Company LLC (Apollo Global Management, Inc.), Koninklijke Philips N.V.
• Inventors: Basin, Grigoriy, Martin, Paul S.
• Primary Examiner(s): Lee, Edmund H.
• Application Number:
  US12/706,149
• Publication Number:
  US 20110198780A1
• Time in Patent Office: 1,603 Days
• Field of Search: None
• US Class Current: 264/266
• CPC Class Codes: B29C 43/18 incorporating preformed parts or layers, e.g. compression moulding around inserts or for coating articles B29C43/206 takes precedence
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/005 Processes
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A flexible film comprising a wavelength converting material is positioned over a light source. The flexible film is conformed to a predetermined shape. In some embodiments, the light source is a light emitting diode mounted on a support substrate. The diode is aligned with an indentation in a mold such that the flexible film is disposed between the support substrate and the mold. Transparent molding material is disposed between the support substrate and the mold. The support substrate and the mold are pressed together to cause the molding material to fill the indentation. The flexible film conforms to the shape of the light source or the mold.

Claims

1. A method comprising:

positioning a flexible film over a light source, the flexible film comprising a transparent material filled with wavelength converting material; and

aligning the light source with an indentation in a mold such that the flexible film is disposed between the light source and the mold;

disposing transparent molding material between the light source and the mold; and

pressing the light source and the mold together to cause the molding material to fill the indentation and to cause the flexible film to conform to a predetermined shape.

2. The method of claim 1 wherein the light source comprises a III-nitride light emitting diode mounted on a support substrate.

3. The method of claim 2 wherein the flexible film is in direct contact with the light emitting diode and conforms to a shape of the light emitting diode.

4. The method of claim 2 wherein the flexible film is in direct contact with the mold and conforms to a shape of the indentation.

5. The method of claim 2 wherein the flexible film comprises a powder phosphor disposed in a silicone film.

6. The method of claim 5 wherein the silicone film is fully cured prior to said positioning.

7. The method of claim 5 wherein the silicone film is partially cured prior to said positioning.

8. The method of claim 5 wherein the flexible film further comprises a non-wavelength converting material, wherein the non-wavelength converting material changes an index of refraction of the flexible film.

9. The method of claim 2 wherein the flexible film is disposed on a support film.

10. The method of claim 9 further comprising removing the support film after pressing the light source and the mold together.

11. The method of claim 2 wherein the indentation is shaped as a lens.

12. The method of claim 2 wherein the flexible film is a first flexible film in direct contact with the light emitting diode, the method further comprising:

positioning a second flexible film comprising a wavelength converting material in direct contact with the mold;

wherein the transparent molding material is disposed between the first flexible film and the second flexible film.

13. The method of claim 2 wherein pressing the light source and the mold together to cause the molding material to fill the indentation and to cause the flexible film to conform to a predetermined shape comprises creating a reduced pressure environment which draws the molding material into the indentation.

14. The method of claim 1 wherein the flexible film is made by evenly spreading a mixture of phosphor and silicone over a support film then at least partially curing the silicone.

15. The method of claim 1 further comprising heating the mold after pressing the light source and the mold together.

16. The method of claim 15 wherein the mold is heated to a temperature that hardens the molding material.

17. The method of claim 1 wherein:

the light source is a first light source;

the method further comprises mounting the first light source and a second light source on a support substrate;

aligning the light source with an indentation in a mold comprises aligning the mold such that the first light source is aligned with a first indentation and the second light source is aligned with a second indentation; and

positioning a flexible film over a light source comprises positioning the flexible film such that wavelength converting material is positioned in a space between the first light source and the second light source.

18. The method of claim 17 wherein after pressing the light source and the mold together, a continuous layer of wavelength converting material is disposed over the first light source, the second light source, and the space between the first light source and the second light source.

19. The method of claim 1 wherein a thickness of wavelength converting material in the flexible film is uniform.