Light emitting diode (LED) packages, systems, devices and related methods

• US 8,610,140 B2
• Filed: 05/02/2012
• Issued: 12/17/2013
• Est. Priority Date: 12/15/2010
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Joo, Sung Chul, Hussell, Christopher P.
• Primary Examiner(s): POTTER, ROY KARL
• Application Number:
  US13/462,450
• Publication Number:
  US 20120307481A1
• Time in Patent Office: 594 Days
• Field of Search: 257/88, 257/E33.066, 362/97.1, 362/241, 438/27
• US Class Current: 257/88
• CPC Class Codes: F21K 9/27 Retrofit light sources for lighting devices with two fittings for each light source, e.g. for substitution of fluorescent tubes
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• 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 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• 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

Packages, systems, and devices for light emitting diodes (LEDs) and related methods are provided. The packages can include a lead frame with an electrically conductive chip carrier comprising an upper surface. An LED can be placed on the upper surface of the electrically conductive chip carrier. A casing can be disposed on the lead frame covering at least a portion of the lead frame. A reflector cavity can be in the casing surrounding the LED. The reflector cavity can have angled side wall portions and angled end wall portions with an angle at which the side wall portions are angled that is different from an angle at which the end wall portions are angled.

Claims

1. A package for a light emitting diode (LED) comprising:

a lead frame comprising an electrically conductive chip carrier comprising an upper surface for attachment of one or more LEDs;

a casing covering at least a portion of the lead frame; and

a reflector cavity disposed at least partially within the casing, the cavity having substantially parallel and angled side wall portions disposed between substantially parallel and angled end wall portions, the angled side wall portions and angled end wall portions surrounding at least a portion of the upper surface of the chip carrier, the side wall portions extending at an angle that is different from an angle at which the end wall portions extend.

2. The package of claim 1 wherein the lead frame is bent and comprises a profile thickness less than approximately 0.5 mm.

3. The package of claim 1 wherein the lead frame is bent and comprises a profile thickness between approximately 0.42 mm to approximately 0.48 mm.

4. The package of claim 1, wherein a height distance between a lower surface of the package and a upper surface of the package is less than approximately 2.0 mm.

5. The package of claim 4, wherein the height distance is from approximately 1.7 mm to approximately 2.0 mm.

6. The package of claim 5, wherein the height distance is approximately 1.9 mm.

7. The package of claim 1, wherein the casing forms outer side walls and outer end walls, with the outer side walls approximately perpendicular to the outer end walls.

8. The package of claim 7, wherein a width distance of the package as measured between outer side walls of the package is less than approximately 3.0 mm.

9. The package of claim 8, wherein the width distance is between approximately 2.7 mm to approximately 3.0 mm.

10. The package of claim 8, wherein the width distance is approximately 2.8 mm.

11. The package of claim 7, wherein a length distance of the LED package as measured between outer end walls of the LED package is less than approximately 3.5 mm.

12. The package of claim 11, wherein the length distance is between approximately 3.0 mm to approximately 3.5 mm.

13. The package of claim 12, wherein the length distance is approximately 3.2 mm.

14. The package of claim 1, wherein the angled side wall portions and angled end wall portions of the reflector cavity have transition wall portions disposed therebetween.

15. The package of claim 14, wherein the transition wall portions are disposed along at least one angle that is different from the angle of the side walls and the angle of the end walls.

16. The package of claim 15, wherein the angle of the transition wall portions is greater than the angle of the side walls and the angle of the end walls.

17. The package of claim 1, wherein the angled side wall portions of the reflector cavity are disposed along an angle of approximately 50°

or more.

18. The package of claim 17, wherein the angled end wall portions of the reflector cavity are disposed along an angle of approximately 70°

or more.

19. A light emitting diode (LED) package comprising:

a lead frame comprising an electrically conductive chip carrier comprising an upper surface;

at least one LED on the upper surface of the electrically conductive chip carrier;

a casing disposed on and covering at least a portion of the lead frame;

a reflector cavity in the casing, the cavity having angled side wall portions and angled end wall portions surrounding the LED, the angled side wall portions of the reflector cavity being disposed along an angle of approximately 50°

or more, and the angled end wall portions of the reflector cavity being disposed along an angle of approximately 70°

or more; and

the LED package having a width distance as measured between outer side walls of the LED package of less than approximately 3.0 mm, and the LED package having a length distance as measured between outer end walls of the LED package of less than approximately 3.5 mm.

20. A method of providing a light emitting device, the method comprising:

providing a lead frame comprising an electrically conductive chip carrier comprising an upper surface;

securing a casing covering at least a portion of the lead frame; and

forming a reflector cavity in the casing surrounding at least a portion of the upper surface, the reflector cavity having substantially parallel and angled side wall portions disposed between substantially parallel and angled end wall portions;

wherein an angle at which the side wall portions are angled is different from an angle at which the end wall portions are angled.

21. The method of claim 20, further comprising disposing an LED on the upper surface of the electrically conductive chip carrier.

22. The method of claim 20, wherein the lead frame is bent and comprises a profile thickness less than approximately 0.5 mm.

23. The method of claim 20, wherein a height distance between a lower surface of the LED package and an upper surface of the LED package is less than approximately 2.0 mm.

24. The method of claim 20, wherein the casing forms outer side walls and outer end walls, with the outer side walls approximately perpendicular to the outer end walls.

25. The method of claim 24, wherein a width distance of the LED package as measured between outer side walls of the LED package is less than approximately 3.0 mm.

26. The method of claim 24, wherein a length distance of the LED package as measured between outer end walls of the LED package is less than approximately 3.5 mm.

27. The method of claim 20, wherein the angled side wall portions and angled end wall portions of the reflector cavity have transition wall portions disposed therebetween.

28. The method of claim 27, wherein the transition wall portions are disposed along an angle different from the angle of the side walls and the angle of the end walls.

29. The method of claim 28, wherein the angle of the transition wall portions are greater than the angle of the side walls and the angle of the end walls.

30. The method of claim 20, wherein the angled side wall portions of the reflector cavity are disposed along an angle different from an angle of the end wall portions of the reflector cavity.

31. The method of claim 30, wherein the angle of the end wall portions is approximately 70°

or more.

32. The method of claim 30, wherein the angle of the side wall portions is approximately 50°

or more.

33. An LED display comprising:

a printed circuit board (PCB); and

an array of LED packages arranged in vertical columns and horizontal rows and electrically connected to the PCB, each of LED packages comprising;

a lead frame comprising an electrically conductive chip carrier comprising an upper surface;

an LED on the upper surface of the electrically conductive chip carrier;

a casing disposed on the lead frame and covering at least a portion of the lead frame; and

a reflector cavity in the casing having angled side wall portions and angled end wall portions surrounding the LED, the side wall portions extending at an angle that is different from an angle at which the end wall portions extend.

34. An LED backlighting device comprising:

a printed circuit board (PCB); and

an array of LED packages arranged in vertical columns and horizontal rows and electrically connected to the PCB, each of LED packages comprising;

a lead frame comprising an electrically conductive chip carrier comprising an upper surface;

an LED on the upper surface of the electrically conductive chip carrier;

a casing disposed on the lead frame and covering at least a portion of the lead frame; and

a reflector cavity in the casing having angled side wall portions and angled end wall portions surrounding the LED, the side wall portions extending at an angle that is different from an angle at which the end wall portions extend.

35. The LED backlighting device of claim 34, wherein the vertical columns and horizontal rows are in a checkerboard pattern.

36. An LED lighting device comprising:

a printed circuit board (PCB); and

a strip of LED packages arranged in a row and electrically connected to the PCB, each of LED packages comprising;

a lead frame comprising an electrically conductive chip carrier comprising an upper surface;

an LED on the upper surface of the electrically conductive chip carrier;

a casing disposed on the lead frame and covering at least a portion of the lead frame; and

a reflector cavity in the casing having angled side wall portions and angled end wall portions surrounding the LED, the side wall portions extending at an angle that is different from an angle at which the end wall portions extend.

37. The LED lighting device of claim 36 or any of the other claims above wherein the LEDs are arranged in a tube device.