LIGHT-EMITTING DIODE PACKAGE ASSEMBLY

• US 20090278139A1
• Filed: 08/12/2008
• Published: 11/12/2009
• Est. Priority Date: 05/12/2008
• Status: Active Grant

• Current Assignee: Joseph Charles Fjelstad
• Original Assignee: Occam Portfolio LLC
• Inventors: Fjelstad, Joseph C.
• Granted Patent: US 8,067,777 B2
• Time in Patent Office: Days
• US Class Current: 257/88
• 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 2224/32245 the item being metallic
• 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 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/83192 wherein the layer connectors are disposed only on another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/92247 the second connecting process involving a wire connector
• CPC Class Codes: H01L 24/24 of an individual high density interconnect connector
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/82 by forming build-up interconnects at chip-level, e.g. for high density interconnects [HDI] interconnection structure between a plurality of semiconductor chips H01L23/5389
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 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 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/12036 PN diode
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/15153 the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/351 Thermal stress
• 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 33/641 : characterized by the materials
• CPC Class Codes: H01L 33/647 : the elements conducting electric current to or from the semiconductor body

Abstract

An electrical device containing multiple light emitting diode (LED) dies each having respective first and second connectors suitable to receive current through the LED die. A common base layer of a first electrically conductive material has cavities into which at least one LED die is mounted with its second connector electrically connected by a conductive bonding material to the first conductive material of the base layer. One or more over-layer sections of a second electrically conductive material each are electrically connected by a bond to at least one of the first connector of a LED die. And an insulator electrically separates the first conductive material of the base layer from the second conductive material of over-layer sections.

Claims

1. An electrical device, comprising:

a plurality of light emitting diode (LED) dies each having respective first connectors and second connectors that are suitable for receiving electrical current through respective of said LED dies;

a common base layer of a first electrically conductive material having a plurality of cavities into which at least one of said plurality of LED dies is mounted such that said second connectors are electrically connected by a conductive bonding material to said first conductive material of said base layer;

at least one over-layer section of a second electrically conductive material wherein each said over-layer is electrically connected by a bond to at least one of said first connectors of said LED dies; and

an insulator electrically separating said first conductive material of said base layer from said second conductive material of said at least one over-layer section.

2. The electrical device of claim 1, wherein:

said first electrically conductive material is also a thermally conductive material.

3. The electrical device of claim 1, wherein:

at least some of said plurality of cavities are shaped to receive light from said at least one of said plurality of LED dies mounted therein and to reflect said light out of the electrical device.

4. The electrical device of claim 1, wherein:

at least some of said plurality of cavities are shaped to mountably contain more than one of said plurality of LED dies.

5. The electrical device of claim 1, wherein:

said at least one over-layer section includes multiple said over-layer sections; and

subsets of said plurality of LED dies are electrically connected each to one said over-layer section and electrically isolated from all other said over-layer sections.

6. The electrical device of claim 1, wherein:

said bond is produced by a member of the set of metal plating, wire bonding, tape automated bonding (TAB), and inkjet printing.

7. The electrical device of claim 1, wherein:

said base layer, said at least one over-layer section, and said insulator are collectively dimensioned thin enough that the electrical device is mechanically flexible or formable.

8. The electrical device of claim 1, further comprising:

a covering over at least said plurality of cavities of a material transparent to light emitted by said plurality of LED dies.

9. The electrical device of claim 8, wherein:

said covering extends over all of said plurality of cavities collectively.

10. The electrical device of claim 8, wherein:

said covering includes a plurality of cover sections each extending over an individual of or subsets of said plurality of cavities.

11. The electrical device of claim 1, further comprising:

a reflector to collectively receive light emitted by said plurality of LED dies and to redirect said light.

12. A process to assemble an electrical device comprising a plurality of light emitting diode (LED) dies each having respective first connectors and second connectors that are suitable for receiving electrical current through respective of the LED dies, the process comprising:

providing a common base layer of a first electrically conductive material surmounted by an insulator in turn surmounted by at least one over-layer section of a second electrically conductive material;

making a plurality of cavities each extending through one of said at least one over-layer section and further through said insulator and into said base layer;

mounting at least one of the plurality of LED dies into each of said plurality of cavities with a conductive bonding material electrically connecting the second connectors of the LED dies to said first conductive material of said base layer; and

bonding the first connectors of the LED dies electrically each to a said at least one over-layer section.

13. The process of claim 12, wherein:

said making includes shaping at least some of said plurality of cavities to receive light from the at least one of the plurality of LED dies mounted therein and reflect said light out of the electrical device.

14. The process of claim 12, wherein:

said making includes sizing at least some of said plurality of cavities to mountably contain more than one of said plurality of LED dies.

15. The process of claim 12, wherein:

said bonding includes a member of the set of metal plating, wire bonding, and tape automated bonding (TAB).

16. The process of claim 12, further comprising:

adding a covering over said plurality of cavities of a material transparent to light emitted by the plurality of LED dies.

17. The process of claim 12, further comprising:

installing a reflector over said plurality of cavities suitable to collectively receive light emitted by the plurality of LED dies and to redirect said light.

18. A process to assemble an electrical device comprising a plurality of light emitting diode (LED) dies each having respective first connectors and second connectors that are suitable for receiving electrical current through respective of the LED dies, the process comprising:

providing a common base layer of a first electrically conductive material wherein said base layer has a principle side;

making a plurality of cavities in said principle side of said base layer;

mounting at least one of the plurality of LED dies into each of said plurality of cavities with a conductive bonding material electrically connecting the second connectors of the LED dies to said first conductive material of said base layer;

providing an insulator over said principle side of said base layer except at said plurality of cavities;

providing at least one over-layer section of a second electrically conductive material over said principle side of said base layer except at said plurality of cavities; and

bonding the first connectors of the LED dies each electrically to a said at least one over-layer section.

19. The process of claim 18, wherein:

said making includes shaping at least some of said plurality of cavities to receive light from the at least one of the plurality of LED dies mounted therein and reflect said light out of the electrical device.

20. The process of claim 18, wherein:

said making includes sizing at least some of said plurality of cavities to mountably contain more than one of said plurality of LED dies.

21. The process of claim 18, wherein:

said bonding includes a member of the set of metal plating, wire bonding, and tape automated bonding (TAB).

22. The process of claim 18, further comprising:

adding a covering over said plurality of cavities of a material transparent to light emitted by the plurality of LED dies.

23. The process of claim 18, further comprising:

installing a reflector over said plurality of cavities suitable to collectively receive light emitted by the plurality of LED dies and to redirect said light.