Power surface mount light emitting die package

• US 8,608,349 B2
• Filed: 02/08/2011
• Issued: 12/17/2013
• 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:
  US13/023,263
• Publication Number:
  US 20110186895A1
• Time in Patent Office: 1,043 Days
• Field of Search: 362/311.01, 362/311.02, 36231103-31105, 362/294, 362/245, 362/341, 362/346, 257/98, 257/100, 257/712
• US Class Current: 362/311.01
• 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 supporting a plurality of traces and a mounting pad on a top surface thereof;

a light emitting diode (LED) mounted centrally over the mounting pad of the substrate, the LED being electrically connected to at least one of the plurality of traces;

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

an encapsulant covering the LED.

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

3. The package of claim 1, wherein the encapsulant comprises an optically clear polymer material.

4. The package of claim 1, wherein the encapsulant comprises silicon.

5. The package of claim 1, wherein the reflector comprises a material having high thermal conductivity.

6. The package of claim 1, wherein the reflector and the substrate serve as heat sinks for dissipating heat generated by the LED.

7. The package of claim 1, further comprising a lens covering the LED.

8. The package of claim 7, wherein the lens is formed by the encapsulant.

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

10. A light emitting die package comprising:

an electrically insulating substrate having a plurality of traces;

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

an encapsulant covering the LED; and

a lens over the LED, a reflector coupled to the substrate and substantially surrounding the LED, the reflector forming an opening in which the encapsulant resides and the lens contacts only the encapsulant.

11. A light emitting die package comprising:

an electrically insulating substrate having a plurality of traces;

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

an encapsulant covering the LED; and

a lens sitting on and adhering to the encapsulant and the lens being free to move relative to the substrate.

12. A light emitting die package comprising:

an electrically insulating substrate having a plurality of traces;

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

an encapsulant covering the LED; and

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