Power surface mount light emitting die package

• US 8,622,582 B2
• Filed: 02/08/2011
• Issued: 01/07/2014
• Est. Priority Date: 09/04/2002
• Status: Expired due to Term

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Loh, Ban P.
• Primary Examiner(s): Alavi, Ali
• Application Number:
  US13/023,273
• Publication Number:
  US 20110186897A1
• Time in Patent Office: 1,064 Days
• Field of Search: 36231101-31105, 362/294, 362/245, 362/341, 362/346, 257/98, 257/100, 257/712
• US Class Current: 362/294
• 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 33/54 having a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/641 characterized by the materials
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A light emitting die package includes a substrate, a reflector plate, and a lens. The substrate has traces for connecting an external electrical power source to a light emitting diode (LED) at a mounting pad. The reflector plate is coupled to the substrate and substantially surrounds the mounting pad, and includes a reflective surface to direct light from the LED in a desired direction. The lens is free to move relative to the reflector plate and is capable of being raised or lowered by the encapsulant that wets and adheres to it and is placed at an optimal distance from the LED chip(s). Heat generated by the LED during operation is drawn away from the LED by both the substrate (acting as a bottom heat sink) and the reflector plate (acting as a top heat sink).

Claims

1. A light emitting die package, comprising:

an electrically insulating substrate comprising a substantially planar top surface and a substantially planar bottom surface;

a plurality of traces disposed on the top surface of the substrate;

a light emitting diode (LED) mounted on the top surface of the substrate and proximate a center of the substrate, and the LED being connected to one or more traces of the plurality of traces; and

a thermal contact pad disposed on the bottom surface of the substrate.

2. The package of claim 1, wherein the plurality of traces extend to at least one side of the substrate.

3. The package of claim 2, wherein the substrate and the portion of the plurality of traces extending around the side to an end portion of the bottom surface have spaces formed therein.

4. The package of claim 1, wherein the electrically insulating substrate has a high thermal conductivity.

5. The package of claim 1, wherein the electrically insulating substrate comprises aluminum nitride.

6. The package of claim 1, further comprising a plurality of connection pads disposed on the bottom surface of the substrate, the plurality of connection pads being electrically connected to the plurality of traces.

7. The package of claim 6, wherein the plurality of connection pads are positioned at edges of the bottom surface.

8. The package of claim 1, wherein the thermal pad is isolated from the plurality of connection pads on the bottom surface.

9. The package of claim 1, wherein an encapsulant covering the LED.

10. The package of claim 9, wherein the encapsulant is composed of an optically clear polymer material.

11. The package of claim 9, further comprising a lens covering the LED.

12. The package of claim 11, wherein the lens is formed by the encapsulant.

13. The package of claim 9, wherein the encapsulant comprises silicon.

14. A light emitting die package comprising:

an electrically insulating substrate comprising a top surface, a bottom surface, and a substantially uniform thickness;

a plurality of traces disposed on the top surface of the substrate;

a light emitting diode (LED) mounted on the top surface of the substrate, proximate a center of the substrate, and the LED being connected to at least one trace of the plurality of traces;

a thermal contact pad disposed on the bottom surface of the substrate; and

a reflector coupled to the substrate and substantially surrounding the LED, the reflector defining a reflection surface.

15. The package of claim 14, wherein the reflector comprises a material having high thermal conductivity.

16. The package of claim 14, wherein the reflector plate and the substrate serve as heat sinks for dissipating heat generated by the LED.

17. The package of claim 14, further comprising a lens covering the LED.

18. A light emitting die package, comprising:

an electrically insulating substrate comprising a top surface and a bottom surface;

a plurality of traces disposed on the top surface of the substrate;

a light emitting diode (LED) mounted on the top surface of the substrate and connected to the plurality of traces;

a thermal contact pad disposed on the bottom surface of the substrate; and

a lens over the LED, the lens sitting on and adhering adheres to the encapsulant, the lens free to move as the encapsulant expands and contracts.

19. A light emitting die package, comprising:

an electrically insulating substrate comprising a top surface and a bottom surface;

a plurality of traces disposed on the top surface of the substrate;

a light emitting diode (LED) mounted on the top surface of the substrate and connected to the plurality of traces;

a thermal contact pad disposed on the bottom surface of the substrate; and

a lens over the LED, the lens sitting on and adhering adheres to the encapsulant and the lens being, free to move relative to the substrate.