Submounts for semiconductor light emitting device packages and semiconductor light emitting device packages including the same

• US 20070253209A1
• Filed: 04/27/2006
• Published: 11/01/2007
• Est. Priority Date: 04/27/2006
• Status: Active Grant

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Keller, Bernd, Medendorp, Nicholas, Loh, Ban
• Granted Patent: US 7,655,957 B2
• Time in Patent Office: Days
• US Class Current: 362/458
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• 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 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01087 Francium [Fr]
• CPC Class Codes: H01L 2924/19107 off-chip wires
• 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 submount for a solid state lighting package includes a support member having upper and lower surfaces, a first side surface, and a second side surface opposite the first side surface, a first electrical bondpad on the upper surface of the support member and having a first bonding region proximate the first side surface of the support member and a second bonding region extending toward the second side surface of the support member, and a second electrical bondpad on the upper surface of the support member having a die mounting region proximate the first side surface of the support member and an extension region extending toward the second side surface of the support member. The die mounting region of the second electrical bondpad may be configured to receive an electronic device. The submount further includes a third electrical bondpad on the upper surface of the support member and positioned between the second side surface of the support member and the die mounting region of the second electrical bondpad.

Claims

1. A submount for a solid state lighting package, comprising:

a support member having an upper surface, a first side surface, and a second side surface opposite the first side surface;

a first electrical bondpad on the upper surface of the support member and having a first bonding region proximate the first side surface of the support member and a second bonding region extending toward the second side surface of the support member;

a second electrical bondpad on the upper surface of the support member having a die mounting region proximate the first side surface of the support member and an extension region extending from the die mounting region toward the second side surface of the support member, wherein the die mounting region of the second electrical bondpad is configured to receive an electronic device; and

a third electrical bondpad on the upper surface of the support member and positioned between the second side surface of the support member and the die mounting region of the second electrical bondpad.

2. The submount of claim 1, wherein the third electrical bondpad further comprises a die mounting region and a wirebonding region.

3. The submount of claim 2, wherein the extension region of the second electrical bondpad extends between the second bonding region of the first electrical bondpad and the die mounting region of the third electrical bondpad.

4. The submount of claim 1, wherein the first bonding region of the first electrical bondpad is located closer to the first side surface of the support member than the second electrical bondpad.

5. The submount of claim 1, wherein the second bonding region of the first electrical bondpad extends closer to the second side surface of the support member than the die mounting region of the second electrical bondpad.

6. The submount of claim 1, wherein the extension region of the second electrical bondpad extends closer to the second side surface of the support member than the second bonding region of the first electrical bondpad.

7. The submount of claim 1, further comprising.

a fourth electrical bondpad on the upper surface of the support member and having a first bonding region proximate the first side surface of the support member and a second bonding region extending toward the second side surface of the support member;

a fifth electrical bondpad on the upper surface of the support member having a die mounting region proximate the first side surface of the support member and an extension region extending toward the second side surface of the support member, wherein the die mounting region of the fifth electrical bondpad is configured to receive an electronic device; and

a sixth electrical bondpad on the upper surface of the support member and positioned between the second side surface of the support member and the die mounting region of the fifth electrical bondpad.

8. The submount of claim 7, wherein the sixth electrical bondpad further comprises a die mounting region and a wirebonding region, and wherein the extension region of the fifth electrical bondpad extends between the second bonding region of the fourth electrical bondpad and the die mounting region of the sixth electrical bondpad.

9. The submount of claim 8, wherein the first bonding region of the fourth electrical bondpad is located closer to the first side surface of the support member than the fifth electrical bondpad.

10. The submount of claim 1, wherein the support member comprises a thermally conductive, electrically insulating material.

11. The submount of claim 10, wherein the support member comprises SiC, AlN and/or diamond.

12. The submount of claim 1, further comprising a solderable metal layer on a lower surface of the support member.

13. The submount of claim 1, wherein the first and second electrical bondpads are separated by a gap of no more than about 0.2 mm.

14. The submount of claim 13, wherein the first and second electrical bondpads are separated by a gap of about 0.1 mm.

15. The submount of claim 13, wherein the second and third electrical bondpads are separated by a gap of no more than about 0.2 mm.

16. The submount of claim 15, wherein the second and third electrical bondpads are separated by a gap of about 0.1 mm.

17. The submount of claim 1, wherein the first, second and third electrical bondpads comprise a layered metal stack including Ti, Ni and Au.

18. A package for a plurality of light emitting devices, comprising:

a body including an upper surface;

a submount on the upper surface of the body, the submount having an upper surface, a first side surface, and a second side surface opposite the first side surface;

a first electrical bondpad on the upper surface of the submount and having a first bonding region proximate the first side surface of the submount and a second bonding region extending toward the second side surface of the submount;

a second electrical bondpad on the upper surface of the submount having a die mounting region proximate the first side surface of the submount and an extension region extending from the die mounting region toward the second side surface of the submount, wherein the die mounting region of the second electrical bondpad is configured to receive an electronic device; and

a third electrical bondpad on the upper surface of the submount and positioned between the second side surface of the submount and the die mounting region of the second electrical bondpad;

19. The package of claim 18, wherein the third electrical bondpad further comprises a die mounting region and a wirebonding region.

20. The package of claim 18, further comprising:

a first light emitting device mounted on the die mounting region of the second electrical bondpad;

a second light emitting device mounted on the third electrical bondpad;

a first external lead on a first side of the package and is electrically connected to the first light emitting device; and

a second external lead on a second side of the package, opposite the first side of the package, and electrically connected to the extension region of the second electrical bondpad.

21. The package of claim 20, further comprising:

a third external lead on the first side of the package and electrically connected to the first electrical bondpad; and

a fourth external lead on the second side of the package and electrically connected to the third electrical bondpad.

22. The package of claim 21, wherein the first and third external leads comprise contacts of a first polarity type, and wherein the second and fourth external leads comprise contacts of a second polarity type, opposite the first polarity type.

23. The package of claim 20, wherein the first external lead is connected to the first light emitting device via a first wirebond connection, and wherein the third external lead is connected to the first electrical bondpad via a second wirebond connection.

24. The package of claim 23, wherein the second bonding region of the first electrical bondpad is connected to the second light emitting diode via a third wirebond connection.

25. The package of claim 21, wherein the fourth external lead is connected to the third electrical bondpad via a fourth wirebond connection, and wherein the second external lead is connected to the extension region of the second electrical bondpad via a fifth wirebond connection.

26. The package of claim 25, wherein the second bonding region of the first electrical bondpad is connected to the second light emitting diode via a sixth wirebond connection.

27. The package of claim 19, wherein the extension region of the second electrical bondpad extends between the second bonding region of the first electrical bondpad and the die mounting region of the third electrical bondpad.

28. The package of claim 18, wherein the first bonding region of the first electrical bondpad is located closer to the first side surface of the submount than the second electrical bondpad.

29. The package of claim 18, wherein the second bonding region of the first electrical bondpad extends closer to the second side surface of the submount than the die mounting region of the second electrical bondpad.

30. The package of claim 18, wherein the extension region of the second electrical bondpad extends closer to the second side surface of the submount than the second bonding region of the first electrical bondpad.

31. The package of claim 18, further comprising.

a fourth electrical bondpad on the upper surface of the submount and having a fourth bonding region proximate the first side surface of the submount and a fifth bonding region extending toward the second side surface of the submount;

a fifth electrical bondpad on the upper surface of the submount having a die mounting region proximate the first side surface of the submount and an extension region extending toward the second side surface of the submount, wherein the die mounting region of the fifth electrical bondpad is configured to receive an electronic device; and

a sixth electrical bondpad on the upper surface of the submount and positioned between the second side surface of the submount and the die mounting region of the fifth electrical bondpad.

32. A package for a light emitting device, comprising:

a package body including a first side surface and a second side surface opposite the first side surface and a central region exposing a plurality of die attach pads;

a plurality of first electrical leads of a first polarity type extending from the first side surface of the molded body; and

a plurality of second electrical leads of a second polarity type, opposite the first polarity type, extending from the second side surface of the molded body;

wherein respective ones of the first electrical leads are electrically connected to corresponding ones of the plurality of die attach pads.

33. The package of claim 32, further comprising:

a reflector cup surrounding the central region of the package body.

34. The package of claim 32, further comprising a recess in the central region of the package body, the recess exposing at least portions of the plurality of first electrical leads.

35. The package of claim 34, wherein the recess comprises a first recess, the package further comprising a second recess in the central region of the package body, the second recess exposing at least portions of the plurality of second electrical leads.

36. The package of claim 32, further comprising:

a plurality of wirebond connections between the first electrical leads and corresponding ones of the die attach pads.

37. The package of claim 32, further comprising:

a plurality of light emitting devices mounted on corresponding ones of the die attach pads; and

a plurality of wirebond connections between the second electrical leads and corresponding ones of the light emitting devices.

38. The package of claim 37, wherein the plurality of light emitting devices are electrically isolated from one another.

39. The package of claim 32, wherein the package body is molded to a leadframe including the plurality of first leads and the plurality of second leads

40. The package of claim 32, further comprising:

a submount on the central region of the package body, wherein the plurality of die attach pads are on the submount.

41. The package of claim 40, wherein the package body includes respective upper and lower surfaces, the package further comprising a heatsink member within the central region and extending from the upper surface to the lower surface of the package body, and wherein the submount is in contact with the heatsink member.