Light emitting diode package assembly

• US 8,067,777 B2
• Filed: 08/12/2008
• Issued: 11/29/2011
• Est. Priority Date: 05/12/2008
• Status: Active Grant

• Current Assignee: Joseph Charles Fjelstad
• Original Assignee: Occam Portfolio LLC
• Inventors: Fjelstad, Joseph C.
• Primary Examiner(s): Maldonado; Julio J
• Application Number:
  US12/190,464
• Publication Number:
  US 20090278139A1
• Time in Patent Office: 1,204 Days
• Field of Search: 438/23, 438/28, 438/29, 438/107, 438/121, 438/26, 257/99, 257/100, 257/E33.056, 257/E33.057, 257/E33.058, 257/E33.059, 257/E25.028, 257/88, 257/91, 313/499, 313/500
• 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 an 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, the LED dies having a top surface, the first connector formed on a central region of said top surface;

a common base layer of a first electrically conductive material, the base layer having a flat surface, the flat surface 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;

a transparent, flat insulator layer covering said flat surface of said common base layer, the transparent, flat insulator layer further covering the top surfaces of the LED dies outside of said central regions but not filling the cavities, the transparent, flat insulator layer having apertures exposing the first connectors, wherein the transparent, flat insulator layer consists entirely of two, spaced, flat surfaces;

a patterned flat over-layer of a second electrically conductive material covering said transparent flat insulator layer and extending into said apertures, the over-layer making electrical contact with said first connectors.

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 one of said plurality of cavities is shaped to mountably contain more than one of said plurality of LED dies.

5. The electrical device of claim 1, wherein:

the patterned flat over-layer comprises metal plating.

6. The electrical device of claim 1, wherein:

said base layer, said over-layer, and said insulator are collectively dimensioned thin enough that the electrical device is mechanically formable.

7. 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.

8. The electrical device of claim 7, wherein:

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

9. The electrical device of claim 7, wherein:

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

10. 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.