Power surface mount light emitting die package

• US 7,659,551 B2
• Filed: 03/30/2007
• Issued: 02/09/2010
• Est. Priority Date: 05/27/2003
• Status: Expired due to Term

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Loh, Ban P.
• Primary Examiner(s): Ton; Anabel M
• Application Number:
  US11/694,046
• Publication Number:
  US 20070181901A1
• Time in Patent Office: 1,047 Days
• Field of Search: 362/294, 362/800, 362/373, 362/249.02, 257/98, 257/100, 257/415
• 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 2924/0002 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 (LED) package is provided which includes a substrate having traces, a LED mounted on the substrate and connected to the traces, and an encapsulant covering the LED. The package includes a lens sitting on the encapsulant and substantially covering the LED. The lens is free to move relative to the substrate.

Claims

1. A light emitting die package, comprising:

a substrate having traces,

a light emitting diode (LED) mounted on the substrate and connected to the traces,

an encapsulant covering the LED, and

a lens sitting on and adhering to the encapsulant and substantially covering the LED, the lens free to move relative to the substrate.

2. The package of claim 1, wherein the lens contacts only the encapsulant.

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

4. The package of claim 1, wherein the substrate is an electrically insulating material having high thermal conductivity.

5. The package of claim 1, wherein

the LED sits on a mounting pad, and

at least one trace extends from the mounting pad to a side of the substrate.

6. The package of claim 2, further comprising:

a reflector plate coupled to the substrate and substantially surrounding the mounting pad, the reflector plate defining a reflection surface.

7. The package of claim 6, wherein the substrate includes flanges along at least one side for mechanically engaging the reflector plate.

8. The package of claim 6, wherein the reflector plate is composed of a material having high thermal conductivity.

9. The package of claim 6, wherein the reflector plate includes a plurality of legs, with at least one leg mechanically engaging the substrate for increased thermal transfer.

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

11. A light emitting die package, comprising:

a substrate including traces for connecting to an LED chip on the substrate, and

an encapsulant covering the LED chip, and

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

12. The package of claim 11, wherein the lens contacts only the encapsulant.

13. The package of claim 11, wherein the encapsulant is composed of an optically clear polymer material.

14. The package of claim 11, wherein the substrate is an electrically insulating material having high thermal conductivity.

15. The package of claim 11, further comprising:

a reflector plate on the substrate and having a circular opening exposing the LED chip, the opening partially filled with the encapsulant which encapsulates the LED chip within the package, the opening forming a circular sidewall within the reflector plate that terminates at a ledge,

wherein the lens sits on a portion of the encapsulant which is formed on the ledge and is free to move relative to the circular sidewall of the reflector plate.

16. The package of claim 15, wherein each of the substrate and reflector plate have a heat sink capability to draw away heat generated by the LED chip during package operation.

17. The package of claim 15, wherein a gap is provided between the lens and the circular sidewall to permit lens movement within the reflector plate.