Packaged light emitting devices including multiple index lenses and methods of fabricating the same

• US 7,952,115 B2
• Filed: 11/24/2009
• Issued: 05/31/2011
• Est. Priority Date: 05/31/2006
• Status: Active Grant

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Keller, Bernd, Medendorp, Nicholas W. Jr., Loh, Ban P.
• Primary Examiner(s): Parker; Kenneth A
• Assistant Examiner(s): Ho; Anthony
• Application Number:
  US12/624,885
• Publication Number:
  US 20100073917A1
• Time in Patent Office: 553 Days
• Field of Search: 257/99, 257/100
• US Class Current: 257/99
• CPC Class Codes: B29C 45/14655 connected to or mounted on a carrier, e.g. lead frame
• CPC Class Codes: B29C 45/1671 with an insert
• CPC Class Codes: B29L 2011/0016 Lenses
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0052 the light source comprising a laser diode coupling into light guides using intermediate optical elements G02B6/4204; semiconductor lasers having optical devices external to the laser cavity H01S5/005
• CPC Class Codes: G02B 19/0071 adapted to illuminate a complete hemisphere or a plane extending 360 degrees around the source
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor

Abstract

A packaged light emitting device includes a substrate, a solid state light emitting device on the substrate, a first generally toroidal lens on the substrate and defining a cavity relative to the solid state light emitting device and having a first index of refraction, and a second lens at least partially within the cavity formed by the first lens and having a second index of refraction that is different from the first index of refraction. The second index of refraction may be higher than the first index of refraction. The lenses may be mounted on the substrate and/or may formed by dispensing and curing liquid encapsulant materials.

Claims

1. A lens for a packaged light emitting device, comprising:

a side lens having a bottom surface, an outward facing upper surface and

an inward facing upper surface and having a first index of refraction,

wherein the inward facing upper surface has a convex profile;

a core lens having a concave side surface that is at least partially within a cavity defined by the inward facing upper surface of the side lens and having a second index of refraction that is different from the first index of refraction, wherein the core lens has a concave lower surface; and

a third lens having a third index of refraction and having a convex upper surface in contact with the concave lower surface of the core lens.

2. The lens of claim 1, wherein the concave side surface of the core lens is in contact with the inward facing upper surface of the side lens.

3. The lens of claim 1, wherein the inward facing upper surface of the side lens has a profile that matches a shape of the concave side surface of the core lens.

4. The lens of claim 1, wherein the second index of refraction is higher than the first index of refraction.

5. The lens of claim 1, wherein the third index of refraction is higher than the first index of refraction.

6. The lens of claim 5, wherein the third index of refraction is higher than the second index of refraction.

7. The lens of claim 5, wherein the third index of refraction is the same as the second index of refraction.

8. The lens of claim 1, wherein both the side lens and the core lens comprise molded silicone.

9. A method of forming a lens for a packaged light emitting device, comprising:

providing a side lens having a bottom surface, an outward facing upper surface, an inward facing upper surface, and a first index of refraction;

positioning a core lens having a second index of refraction that is different from the first index of refraction at least partially within a cavity defined by the inward facing upper surface of the side lens wherein the core lens has a concave lower surface;

positioning a third lens having a third index of refraction and having a convex upper surface in contact with the concave lower surface of the core lens; and

adhering the side lens to the core lens.

10. The method of claim 9, wherein the inward facing upper surface of the side lens has a convex profile, the core lens has a concave side surface, and wherein positioning the core lens comprises placing the concave side surface of the core lens in contact with the inward facing upper surface of the side lens.

11. The method of claim 10, wherein the inward facing upper surface of the side lens has a profile that matches a shape of the concave side surface of the core lens.

12. The method of claim 9, wherein the second index of refraction is higher than the first index of refraction.

13. The method of claim 9, wherein the third index of refraction is higher than the first index of refraction.

14. The method of claim 13, wherein the third index of refraction is higher than the second index of refraction.

15. The method of claim 13, wherein the third index of refraction is the same as the second index of refraction.

16. The method of claim 9, wherein both the side lens and the core lens comprise molded silicone.

17. A packaged light emitting device, comprising:

a substrate;

a solid state light emitting device on the substrate;

a side lens on the substrate, the side lens having a bottom surface, an outward facing upper surface and an inward facing upper surface and having a first index of refraction, wherein the inward facing upper surface has a convex profile;

a core lens having a concave side surface that is at least partially within a cavity defined by the inward facing upper surface of the side lens and having a second index of refraction that is different from the first index of refraction, wherein the core lens has a concave lower surface; and

a third lens having a third index of refraction and having a convex upper surface in contact with the concave lower surface of the core lens.

18. The packaged light emitting device of claim 17, wherein the concave side surface of the core lens is in contact with the inward facing upper surface of the side lens.