Multi-chip light emitter packages and related methods

• US 9,172,012 B2
• Filed: 03/12/2013
• Issued: 10/27/2015
• Est. Priority Date: 10/31/2007
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Andrews, Peter S., Wilcox, Kurt S., Lowes, Theodore, Keller, Bernd P.
• Primary Examiner(s): Lee, Calvin
• Application Number:
  US13/796,045
• Publication Number:
  US 20130256710A1
• Time in Patent Office: 959 Days
• Field of Search: 257 95-100, 257699-712, 257/E33.056, 438 22- 29
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49113 the connectors connecting different bonding areas on the semiconductor or solid-state body to a common bonding area outside the body, e.g. converging wires
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• 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 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• 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 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01087 Francium [Fr]
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/12035 Zener diode
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19107 : off-chip wires
• CPC Class Codes: H01L 33/405 : Reflective materials
• CPC Class Codes: H01L 33/54 : having a particular shape
• CPC Class Codes: H01L 33/58 : Optical field-shaping elements
• 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 33/64 : Heat extraction or cooling elements
• CPC Class Codes: H01L 33/647 : the elements conducting electric current to or from the semiconductor body

Abstract

Light emitter packages having multiple light emitter chips, such as light emitting diode (LED) chips, and related methods are provided. In one embodiment, a light emitter package can include a ceramic submount. An array of light emitter chips can be disposed over a portion of the submount, and each light emitter chip can include a horizontal chip structure having positive and negative electrical contacts disposed on a same side. The positive and negative electrical contacts can be adapted to electrically communicate to conductive portions of the submount. Light emitter packages can further include a lens overmolded on the submount and covering a portion of the array.

Claims

1. A method of providing a light emitter package, the method comprising:

providing a submount having a planar upper surface;

providing an array of light emitter chips disposed over a portion of the planar upper surface of the submount in a rectangular arrangement;

connecting each light emitter chip of the array of light emitter chips to conductive portions of the submount via non-wire bond connections; and

providing a lens over the array of light emitter chips, wherein the lens is asymmetric about a central axis of the submount that is orthogonal to the planar upper surface of the submount.

2. The method of claim 1, wherein directly connecting each light emitter chip comprises connecting the bottom side of each light emitter chip to conductive portions of the submount via a eutectic direct die attach process.

3. The method of claim 1, wherein conductive portions of the submount comprise a positive contact pad, a negative contact pad, and at least one intermediate contact pad.

4. The method of claim 3, further comprising providing portions of intermediate contact pad between portions of the positive and negative contact pads.

5. The package of claim 1, wherein providing an asymmetric lens comprises overmolding the asymmetric lens.

6. The method of claim 1, wherein each light emitter chip comprises a horizontal chip structure having positive and negative electrical contacts disposed on a same side.

7. The method of claim 6, wherein the positive and negative electrical contacts are disposed on a bottom side of each light emitter chip.

20. The package of claim 1, wherein the package comprises a first contact pad, a second contact pad, and a third contact pad.

21. The package of claim 20, wherein each of the first, second, and third contact pads comprise centrally disposed leg portions.

22. The package of claim 21, wherein leg portions of the second contact pad are disposed between leg portions of the first and third contact pads.

8. A light emitter package comprising:

an array of light emitter chips disposed on a submount in a rectangular arrangement and connected without wire bonds, wherein the array of light emitter chips comprises a center point coincident with the center point of the submount;

a lens disposed over the array of light emitter chips, and wherein the lens is asymmetric about the center point of the array of light emitter chips; and

a positive electrical pad, an intermediate electrical pad, and a negative electrical pad.

9. The package of claim 8, wherein a portion of the intermediate contact pad is disposed between portions of the positive and negative contact pads.

10. The package of claim 8, wherein a portion of the positive contact pad is adjacent to a portion of the negative contact pad.

11. The package of claim 8, wherein the positive contact pad is adjacent to intermediate contact pad along at least three sides.

12. The package of claim 8, wherein the negative contact pad is adjacent to intermediate contact pad along at least three sides.

13. The package of claim 8, wherein the array defines an LED chip-populated area having an aspect ratio greater than 1.

14. The package of claim 8, wherein the array defines an LED chip-populated area having an aspect ratio greater than 2.

15. The package of claim 8, wherein the array defines an LED chip-populated area having an aspect ratio greater than 3.

16. A light emitter package comprising:

a submount comprising a ceramic material having a planar upper surface;

an array of light emitter chips disposed on a portion of the planar upper surface of the submount, wherein each light emitter chip comprises a horizontal chip structure having positive and negative electrical contacts disposed on a same side, wherein the positive and negative electrical contacts are adapted to electrically communicate to conductive portions of the submount; and

a lens overmolded on the planar upper surface of the submount and covering a portion of the array, wherein the lens is asymmetric about a central axis of the submount that is orthogonal to the planar upper surface of the submount.

17. The package of claim 16, wherein the package is adapted to deliver approximately 100 lumens per watt (LPW) or more at 1.5 amps (A) and/or 9 watts (W).

18. The package of claim 16, wherein the package is configured to refract light emitted by the array of light emitter chips toward a preferential direction.

19. The package of claim 18, wherein:

the array of light emitter chips defines an emitter axis; and

the lens has an outer surface and a centerline which is offset from the emitter axis toward the preferential direction.

23. The package of claim 16, wherein the light emitter chips comprise light emitting diode (LED) chips.

24. The package of claim 23, wherein the LED chips are approximately 1000 μ

m×

1000 μ

m in size.

25. The package of claim 23, wherein the LED chips are approximately 350 μ

m ×

350 μ

m in size.

26. The package of claim 23, wherein the package comprises an array of eight LED chips.

27. The package of claim 23, wherein the package comprises an array of forty-eight LED chips.