Light emitting diode (LED) arrays including direct die attach and related assemblies

• US 9,754,926 B2
• Filed: 02/14/2011
• Issued: 09/05/2017
• Est. Priority Date: 01/31/2011
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Donofrio, Matthew, Edmond, John Adam, Kong, Hua-Shuang, Andrews, Peter S., Emerson, David Todd
• Primary Examiner(s): Nadav, Ori
• Application Number:
  US13/027,006
• Publication Number:
  US 20120193649A1
• Time in Patent Office: 2,395 Days
• Field of Search: 257 79- 81, 257 98-100
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• 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

An electronic device may include a packaging substrate having a packaging substrate face with a plurality of electrically conductive pads on the packaging substrate face. A first light emitting diode die may bridge first and second ones of the electrically conductive pads. More particularly, the first light emitting diode die may include first anode and cathode contacts respectively coupled to the first and second electrically conductive pads using metallic bonds. Moreover, widths of the metallic bonds between the first anode contact and the first pad and between the first cathode contact and the second pad may be at least 60 percent of a width of the first light emitting diode die. A second light emitting diode die may bridge third and fourth ones of the electrically conductive pads. The second light emitting diode die may include second anode and cathode contacts respectively coupled to the third and fourth electrically conductive pads using metallic bonds. Widths of the metallic bonds between the second anode contact and the second pad and between the second cathode contact and the third pad may be at least 60 percent of a width of the first light emitting diode die.

Claims

1. An electronic device comprising:

a packaging substrate having a packaging substrate face

a first electrically conductive contact pad at the packaging substrate face;

a second electrically conductive contact pad at the packaging substrate face, the second electrically conducting pad comprising first and second portions disposed on opposite sides of an intervening portion of the first electrically conductive contact pad;

a first light emitting diode die bridging the first portion of the second electrically conductive pad and the intervening portion of the first electrically conductive pad, the first light emitting diode die including first anode and cathode contacts respectively coupled to the first and second electrically conductive pads using metallic bonds, wherein widths of the metallic bonds between the first anode contact and the first electrically conductive pad and between the first cathode contact and the second electrically conductive pad are at least 60 percent of a width of the first light emitting diode die;

a second light emitting diode die the second portion of the second electrically conductive pad and the intervening portion of the first electrically conductive pad, the second light emitting diode die including second anode and cathode contacts respectively coupled to the first and second electrically conductive pads using metallic bonds, wherein widths of the metallic bonds between the second anode contact and the first electrically conductive pad and between the second cathode contact and the second electrically conductive pad are at least 60 percent of a width of the first light emitting diode die; and

a filler on the packaging substrate between the first and second electrically conductive pads, wherein the filler is reflective and electrically insulating.

2. An electronic device according to claim 1 wherein contact areas of the first light emitting diode die with the first and second electrically conductive pads are asymmetric, and wherein contact areas of the second light emitting diode die with the first and second electrically conductive pads are asymmetric.

3. An electronic device according to claim 2 wherein there is at least a 25 percent difference between a contact area of the metallic bond between the first anode contact and the first electrically conductive pad and a contact area of the metallic bond between the first cathode contact and the second electrically conductive pad, and wherein there is at least a 25 percent difference between a contact area of the metallic bond between the second anode contact and the first electrically conductive pad and a contact area of the metallic bond between the second cathode contact and the second electrically conductive pad.

4. An electronic device according to claim 1 wherein a combined contact area of the metallic bonds between the first anode contact and the first electrically conductive pad and between the first cathode contact and the second electrically conductive pad is at least 70 percent of a surface area of the first light emitting diode die, and wherein a combined contact area of the metallic bonds between the second anode contact and the first electrically conductive pad and between the second cathode contact and the second electrically conductive pad is at least 70 percent of a surface area of the second light emitting diode die.

5. An electronic device according to claim 1 wherein the intervening portion of the first electrically conductive pad comprises a finger extending between the first and second portions of the second electrically conductive pad.

6. An electronic device according to claim 1,

wherein the first light emitting diode die comprises a first diode region including therein a first n-type layer and a first p-type layer, wherein the first anode contact ohmically contacts the first p-type layer, and wherein the first cathode contact ohmically contacts the first n-type layer, and

wherein the second light emitting diode die comprises a second diode region including therein a second n-type layer and a second p-type layer, wherein the second anode contact ohmically contacts the second p-type layer, and wherein the second cathode contact ohmically contacts the second n-type layer.

7. An electronic device according to claim 1 further comprising a third light emitting diode die bridging the first portion of the second electrically conductive pad and the intervening portion of the first electrically conductive pad, the third light emitting diode die including third anode and cathode contacts respectively coupled to the first and second electrically conductive pads using metallic bonds.