LED package assembly

• US 20050135105A1
• Filed: 12/19/2003
• Published: 06/23/2005
• Est. Priority Date: 12/19/2003
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds Lighting US LLC (Apollo Global Management, Inc.)
• Inventors: Steward, Robert L., Teixeira, Fernando M.
• Granted Patent: US 7,321,161 B2
• Time in Patent Office: Days
• US Class Current: 362/294
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/12041 LED
• 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
• CPC Class Codes: H01L 33/642 characterized by the shape

Abstract

An LED package includes a datum reference feature that is external to the insulating body of the LED package and has a known, fixed relationship to the heat sink. The LED die is mounted to the heat sink such that the LED die has a fixed relationship to the heat sink. Accordingly, the reference datum feature provides a frame of reference to the position of the LED die within the LED package. The reference datum feature may be mounted to the heat sink or integrally formed from the heat sink. A pick-and-place head holds the LED package by engaging the datum reference feature, e.g., with an alignment pin. In addition, the LED package may include a lead that extends laterally into the insulating body, and extends towards the LED die to reduce the vertical distance between the lead and the LED die.

Claims

1. An assembly comprising:

an LED die;

a heat sink, the LED die being coupled to the heat sink so that the LED die has a known positional relationship to the heat sink;

an insulating body at least partially surrounding the heat sink; and

at least one datum reference feature external to the insulating body, the datum reference feature having a fixed relationship to the heat sink such that the datum reference feature provides a reference for the position of the LED die.

2. The assembly of claim 1, wherein there are two datum reference features, the two datum reference features are located at approximately opposite sides of the insulating body.

3. The assembly of claim 1, wherein the datum reference feature is one of a semicircular and “

V”

shaped notch.

4. The assembly of claim 1, further comprising a collar with an aperture approximately in the center of the collar, the datum reference feature being integrally formed from the collar, the collar being mounted on the heat sink by inserting at least a portion of the heat sink through the aperture in the collar.

5. The assembly of claim 4, wherein the collar includes a tab, the datum reference feature is formed by at least a portion of the tab.

6. The assembly of claim 4, wherein the datum reference feature is formed by an indentation in the collar.

7. The assembly of claim 1, wherein the datum reference feature is integrally formed from the heat sink.

8. The assembly of claim 1, wherein the insulating body includes a recessed portion that exposes the datum reference feature.

9. The assembly of claim 1, wherein the insulating body includes corners and the datum reference feature is located at a corner of the insulating body.

10. The assembly of claim 1, further comprising a submount, the LED die being mounted on the submount and the submount being mounted on the heat sink.

11. The assembly of claim 1, further comprising a mounting surface, the heat sink coupled to the mounting surface.

12. The assembly of claim 11, further comprising at least one alignment pin coupled to the mounting surface, wherein the alignment pin and datum reference feature are configured to align the heat sink to a desired location on the mounting surface.

13. The assembly of claim 1, further comprising a second LED die coupled to the heat sink.

14. A method of assembling an LED package, the method comprising:

providing a datum reference feature indicative of the position of a heat sink;

mounting an LED die to the heat sink;

forming an insulating body around at least a portion of the heat sink and so that the datum reference feature is external to the insulating body.

15. The method of claim 14, wherein providing a datum reference feature comprises mounting an element that includes the datum reference feature to the heat sink.

16. The method of claim 15, wherein the element that includes the datum reference feature is a collar having an aperture, and mounting the element to the heat sink comprises inserting at least a portion of the heat sink through the aperture in the collar.

17. The method of claim 14, wherein providing a datum reference feature comprises providing a heat sink with an integrally formed datum reference feature.

18. The method of claim 15, further comprising mount a second LED die to the heat sink.

19. A method comprising:

providing an LED package having a datum reference feature that is external to the insulating body of the LED package, the datum reference feature having a fixed relationship to the LED die in the LED package;

engaging the datum reference feature with an alignment pin; and

holding the LED package using the engaged datum reference feature.

20. The method of claim 19, further comprising:

placing the LED package on a surface to which the LED package is to be mounted while holding the LED die package using the engaged datum reference feature; and

bonding the LED package to the surface.

21. The method of claim 20, wherein the alignment pin is coupled to the surface.

22. The method of claim 21, further comprising:

inspecting the LED package while holding the LED package using the engaged datum reference feature.

23. An LED package comprising:

an LED die;

a heat sink, the LED die being coupled to the heat sink;

an insulating body at least partially surrounding the heat sink;

a lens mounted to the insulating body;

a plurality of leads extending out of the insulating body, at least one lead extending laterally into the insulating body at a first vertical distance from the LED die, the lead extending through the insulating body to a second vertical distance from the LED die, the second vertical distance being less than the first vertical distance; and

a bond wire electrically coupling the lead and the LED die.

24. The LED package of claim 23, wherein the lens has a base, wherein the lead extends laterally under the base of the lens.

25. The LED package of claim 23, further comprising:

a submount, the LED die being mounted on the submount and the submount being mounted on the heat sink, the bond wire being directly coupled to the submount and the lead.

26. The LED package of claim 23, wherein the lead further extends laterally at the second vertical distance.

27. The LED package of claim 26, wherein the lead has a “

Z”

shape within the insulating body.

28. The LED package of claim 26, wherein the wire bond is coupled to the at least one lead at the lateral extent of the lead at the second vertical distance.

29. The LED package of claim 23, wherein the lead extends laterally around at least a portion of the LED die.

30. The LED package of claim 23, further comprising a second LED die coupled to the heat sink.