Aligned multiple emitter package

• US 9,722,158 B2
• Filed: 10/15/2012
• Issued: 08/01/2017
• Est. Priority Date: 01/14/2009
• Status: Active Grant

• Current Assignee: Cree Huizhou Solid State Lighting Company Limited (Smart Global Holdings Incorporated)
• Original Assignee: Cree Huizhou Solid State Lighting Company Limited (Smart Global Holdings Incorporated)
• Inventors: Lau, Yue Kwong Victor, Wang, Xuan, Emerson, David Todd, Chan, Alex Chi Keung
• Primary Examiner(s): Gupta, Raj R
• Application Number:
  US13/652,241
• Publication Number:
  US 20130038644A1
• Time in Patent Office: 1,751 Days
• Field of Search: 257 98
• 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 23/49861 Lead-frames fixed on or encapsulated in insulating substrates H01L23/4985, H01L23/49805 take precedence
• 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 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 2924/14 Integrated circuits
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• 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
• CPC Class Codes: H01L 33/647 the elements conducting electric current to or from the semiconductor body

Abstract

A multiple element emitter package is disclosed for increasing color fidelity and heat dissipation, improving current control, and increasing rigidity of the package assembly. In one embodiment, the package comprises a casing with a cavity extending into the interior of the casing from a first main surface. A lead frame is at least partially encased by the casing, the lead frame comprising a plurality of electrically conductive parts carrying a linear array of LEDs. Electrically conductive parts, separate from the parts carrying the LEDs, have a connection pad, wherein the LEDs are electrically coupled to the connection pad, such as by a wire bond. This arrangement allows for a respective electrical signal to be applied to each of the LEDs. The emitter package may be substantially waterproof, and an array of the emitter packages may be used in an LED display such as an indoor and/or outdoor LED screen.

Claims

1. An electrically conductive lead frame for a multiple emitter package, comprising:

a plurality of electrically conductive cathode parts on a first side of said lead frame each comprising an attach pad portion for carrying at least one light emitting device, with each attach pad being electrically coupled to its said at least one light emitting device, each of said plurality of electrically conductive cathode parts further comprising through-holes and V-cuts, wherein at least one of said V-cuts partially extends into a first surface of each of said plurality of electrically conductive cathode parts and at least one other of said V-cuts partially extends into a second surface of each of said plurality of electrically conductive cathode parts, said second surface opposite said first surface, wherein at least one of said through-holes intersects with at least one of said V-cuts;

a corresponding plurality of electrically conductive anode parts on the opposite side of said lead frame from said cathode parts, each of said anode parts comprising a connection pad portion configured to allow electrical connection to one of said at least one light emitting device, wherein said attach pads and connection pads are configured to hold light emitting devices in linear alignment; and

side indentations in at least some of said anode and cathode parts, at least some of said side indentations having a wave shape.

2. The lead frame of claim 1, wherein said light emitting devices are adapted to be energized to produce in combination a substantially full range of colors.

3. The lead frame of claim 1, wherein said light emitting devices comprise light emitting diodes (LEDs).

4. The lead frame of claim 3, wherein said LEDs comprise at least two contacts, one of which is electrically coupled to one of said attach pads and the other of which is electrically coupled to one of said connection pads.

5. The lead frame of claim 3, wherein said LEDs comprise red, green, and blue LEDs.

6. The lead frame of claim 3, wherein each of said light emitting diodes is coupled to a respective attach pad via solder.

7. The lead frame of claim 1, wherein the linear array of light emitting devices extends in a first direction, said anode parts are in parallel relationship with each other, and said cathode parts are in parallel relationship with each other, each of said anode parts and said cathode parts extending in a direction orthogonal to said first direction.

8. The lead frame of claim 1, wherein said anode and cathode parts are made of sheet metal.

9. The lead frame of claim 1, wherein each of said LEDs is electrically coupled to a connection pad by means of a wire bond.

10. The lead frame of claim 1, further comprising a casing of dark or black ceramic.

11. The lead frame of claim 1, wherein said plurality of electrically conductive anode parts comprise through-holes.

12. The lead frame of claim 1, each of said plurality of electrically conductive anode parts further comprising V-cuts.

13. The lead frame of claim 12, wherein said V-cuts of each of said plurality of electrically conductive anode parts partially extend into an upper surface of each of said plurality of electrically conductive anode parts.

14. The lead frame of claim 1, wherein each of said side indentations provides a narrowed portion in said cathode or anode part between an attach pad or connection pad and an outer portion of said cathode or anode part, respectively, said outer portions being wider than said narrowed portions.