Collimating light from an LED device

• US 20050263784A1
• Filed: 05/27/2004
• Published: 12/01/2005
• Est. Priority Date: 05/27/2004
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Yaw, Yean Chon, Hwang, Yi Feng
• Granted Patent: US 7,230,280 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A technique for collimating light from a Light Emitting Diode (LED) device involves emitting light from an LED die, collimating the light with a parabolic reflector, and further collimating the light with a lens. A device constructed according to the technique includes an LED die, a lens for collimating light, and a parabolic reflector for collimating light from the LED die toward the lens.

Claims

1. A Light Emitting Diode (LED) device, comprising:

a lens;

a parabolic reflector; and

an LED die, the lens, parabolic reflector, and LED die being configured such that light emitted from the LED die is reflected by the parabolic reflector past the LED die and towards the lens.

2. The device of claim 1 wherein the lens and LED die are aligned with the center axis of the parabolic reflector.

3. The device of claim 2 wherein the lens and the parabolic reflector are formed on opposite ends of a monolithic structure.

4. The device of claim 1 wherein the parabolic reflector and the lens are formed in a monolithic structure that encapsulates the LED die.

5. The device of claim 4 wherein the parabolic reflector and the lens are positioned at opposite ends of the monolithic structure.

6. The device of claim 1 further comprising an epoxy encapsulant, wherein the LED die is located within the encapsulant and wherein the parabolic reflector is formed at a surface of the epoxy encapsulant.

7. The device of claim 1 further including a leadframe with a narrow optical profile relative to the emitted light.

8. The device of claim 1 further comprising an I-beam leadframe having a height dimension that is large relative to a width dimension.

9. The device of claim 1 further comprising a multi-prong leadframe, wherein the LED die is connected to the multi-prong leadframe.

10. The device of claim 1 further comprising a reflector cup configured to collimate light from the LED die toward the parabolic reflector.

11. The device of claim 1 further comprising an I-beam leadframe that is configured for side firing relative to a surface on which the device is mounted.

12. A method of operating a Light Emitting Diode (LED) device, comprising:

emitting light from an LED die;

collimating the light from the LED die with a parabolic reflector; and

collimating the light from the parabolic reflector with a lens.

13. The method of claim 12 further comprising collimating the light with a reflector cup.

14. The method of claim 12 further comprising providing a leadframe with a narrow optical profile for supporting the LED die between the parabolic reflector and the lens.

15. The method of claim 12 wherein the collimating the light with a parabolic reflector includes reflecting light past the LED die toward the lens.

16. The method of claim 12 further comprising locating the LED die along the center axis of the parabolic reflector.

17. A Light Emitting Diode (LED) device, comprising:

an LED die for emitting light;

a reflector cup, configured to contain the LED die, for collimating light from the LED die;

a parabolic reflector for collimating light from the LED die and the reflector cup, wherein the reflector cup intersects the center axis of the parabolic reflector; and

a lens for collimating light from the parabolic reflector, wherein the parabolic reflector reflects light past the reflector cup toward the lens.

18. The device of claim 17 further comprising a leadframe, having multiple I-beam leadframe extensions, connected to the reflector cup, wherein the parabolic reflector reflects light past the leadframe.

19. The device of claim 17 further comprising a leadframe, having a narrow optical profile, connected to the reflector cup, wherein the parabolic reflector reflects light past the leadframe.

20. The device of claim 17 wherein the parabolic reflector and the lens are formed in a monolithic structure around the LED die and the reflector cup.