Light emitter packages and methods

• US 10,295,124 B2
• Filed: 02/27/2013
• Issued: 05/21/2019
• Est. Priority Date: 02/27/2013
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Andrews, Peter Scott
• Primary Examiner(s): Alam, Mohammed R
• Application Number:
  US13/779,146
• Publication Number:
  US 20140239316A1
• Time in Patent Office: 2,274 Days
• Field of Search: 257 98
• CPC Class Codes: F21K 9/233 specially adapted for generating a spot light distribution, e.g. for substitution of reflector lamps
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]

Abstract

Light emitter packages and related methods having improved performance are disclosed. In one aspect, a light emitter package can include at least one light emitter chip disposed over a substrate or submount. In some aspects, the package can include a reflective polymeric material or polymeric reflector (sometimes referred to as a “solder mask” or “solder mask material”), a reflective material, and a conductive material disposed adjacent each other within a portion of the light emitter package. In some aspects, the reflective material can include a metallic material or metallic reflector applied to side walls of traces and/or within portions of a gap between traces prior to application of the reflective polymeric material within the gap.

Claims

1. A light emitter package comprising:

a substrate for supporting at least one light emitter chip;

a first electrically conductive layer and a second electrically conductive layer on the substrate, comprising a gap between the first and second electrically conductive layers, wherein each of the first and second electrically conductive layers has a side wall;

a reflective stack of materials comprising;

a reflective layer; and

a reflective polymeric material disposed on the reflective layer, wherein the reflective polymeric material is thicker than the underlying reflective layer and is disposed in and substantially extends across a width of the gap; and

wherein the reflective stack of materials comprising the reflective layer and reflective polymeric material is disposed over the side walls of the first and second electrically conductive layers, wherein the side walls of the first and second electrically conductive layers having the reflective stack of materials disposed thereon are substantially orthogonal with respect to the substrate.

2. The light emitter package of claim 1, wherein the reflective polymeric material is white.

3. The light emitter package of claim 1, wherein the substrate comprises a ceramic based material.

4. The light emitter package of claim 3, wherein the substrate comprises aluminum nitride (AlN).

5. The light emitter package of claim 3, wherein the substrate comprises alumina (Al₂O₃).

6. The light emitter package of claim 1, wherein the reflective layer comprises a layer of silver (Ag).

7. The light emitter package of claim 6, wherein the Ag is electroless plated.

8. The light emitter package of claim 6, wherein the Ag is between 0.2 μ

m and 0.5 μ

m thick.

9. The light emitter package of claim 1, wherein the first and second electrically conductive layers comprise copper (Cu).

10. The light emitter package of claim 9, wherein the Cu is electroplated.

11. The light emitter package of claim 9, wherein the Cu is between 20 and 70 μ

m thick.

12. The light emitter package of claim 1, further comprising at least one light emitting diode (LED) chip.

13. The light emitter package of claim 1, further comprising multiple light emitting diode (LED) chips.

14. The light emitter package of claim 1, wherein the reflective polymeric material, the reflective layer, and the substrate are disposed adjacent each other within a portion of the light emitter package, and wherein the substrate comprises a ceramic based material.

15. A light emitter package comprising:

a substrate comprising a substrate surface;

a first trace disposed over the substrate surface;

a second trace disposed over the substrate surface;

a gap disposed between the first and second traces;

a plurality of traces centrally disposed between the first and second traces; and

at least one light emitter chip disposed over the substrate surface, the chip being adapted to electrically communicate with portions of the first and second traces;

wherein first and second side walls of the first and second traces, respectively, are orthogonally disposed with respect to the substrate surface and oppose each other across the gap, and wherein the first and second side walls are coated with a reflective plastic material and a metallic material, wherein the reflective plastic material is disposed directly adjacent to the first and second side walls, within the gap, wherein the reflective plastic material is disposed in and extends substantially across a width of the gap.

16. The light emitter package of claim 15, further comprising more than five light emitter chips.

17. The light emitter package of claim 15, further comprising more than 20 light emitter chips.

18. The light emitter package of claim 15, further comprising 96 light emitter chips.

19. The light emitter package of claim 15, further comprising a plurality of gaps provided between individual traces of the plurality of traces.

20. The light emitter package of claim 19, wherein each gap of the plurality of gaps is disposed between adjacent side walls of adjacent traces of the plurality of traces.

21. The light emitter package of claim 20, wherein each of the adjacent side walls comprises a layer of copper and an outermost layer of silver.

22. The light emitter package of claim 19, wherein the reflective plastic material is provided within a portion of each gap of the plurality of gaps.

23. The light emitter package of claim 15, further comprising an optical element.

24. A method of producing a light emitter package, the method comprising:

providing a substrate for supporting a light emitter;

providing an electrically conductive layer having at least two side walls and a gap therebetween on the substrate;

providing a reflective stack of materials comprising;

a reflective layer; and

a reflective polymeric material disposed over the reflective layer, wherein the reflective polymeric material is thicker than the underlying reflective layer and is disposed in and substantially extends across a width of the gap; and

providing the reflective stack of materials comprising the reflective layer and reflective polymeric material over the at least two side walls of the electrically conductive layer, wherein the at least two side walls of the electrically conductive layer having the reflective stack of materials disposed thereon are substantially orthogonal with respect to the substrate.

25. The method of claim 24, wherein the light emitter package comprises a conductive layer, and wherein the reflective stack of materials is disposed over a portion of a floor of a gap.

26. The method of claim 24, further comprising providing one or more light emitter chips over the substrate.

27. The method of claim 24, wherein providing the substrate comprises providing an aluminum nitride (AlN) or (Al₂O₃) substrate.

28. The method of claim 24, further comprising side walls of first and second opposing conductive traces and a floor of a gap disposed between the side walls of the first and second opposing conductive traces.

29. The method of claim 28, further comprising burnishing and polishing upper surfaces of the first and second opposing conductive traces.

30. The method of claim 29, further comprising providing a second reflective layer over the burnished and polished upper surfaces of the first and second opposing conductive traces.

31. A light emitter package comprising:

a substrate for at least one light emitter chip;

a conductive layer on the substrate;

a trace disposed over the substrate, the trace comprising at least two side walls and a gap therebetween;

a first reflective layer disposed on portions of the substrate, the conductive layer and on a portion of the trace; and

a second reflective layer disposed over the first reflective layer and disposed in and substantially extending across a width of the gap;

wherein the first reflective layer is disposed over a side wall of the conductive layer;

wherein the second reflective layer is a reflective polymeric material that is electrically insulating, thermally insulating, and both light reflective and light permeable to re-reflect permeated light from the light emitter package via the underlying first reflective layer.

32. The light emitter package of claim 31, wherein the light emitter package comprises a light blocking surface, and wherein the first reflective layer is directly disposed over the light blocking surface.

33. The light emitter package of claim 32, wherein the light blocking surface comprises an electrically conductive material.

34. The light emitter package of claim 33, wherein the electrically conductive material comprises copper (Cu).

35. The light emitter package of claim 31, wherein the first reflective layer comprises a metallic coating.

36. The light emitter package of claim 35, wherein the metallic coating comprises silver (Ag).

37. The light emitter package of claim 31, wherein the second reflective layer is white.

38. The light emitter package of claim 31, wherein the second reflective layer comprises plastic.

39. The light emitter package of claim 31, wherein the second reflective layer comprises a Lambertian coating.

40. The light emitter package of claim 31, wherein the first reflective layer is specularly reflective and wherein the second reflective layer is diffusively reflective.

41. The light emitter package of claim 31, wherein the substrate comprises a ceramic based material.

42. The light emitter package of claim 41, wherein the substrate comprises aluminum nitride (AlN).

43. The light emitter package of claim 41, wherein the substrate comprises alumina (Al₂O₃).

44. A method of producing a light emitter package, the method comprising:

providing a substrate;

providing a conductive layer on the substrate;

providing a trace over the substrate, the trace comprising at least two side walls and a gap therebetween;

providing a first reflective layer on portions of the substrate and on a portion of the trace; and

providing a second reflective layer over the first reflective layer and disposed in and substantially extending across a width of the gap;

wherein the first reflective layer is disposed over a side wall of the conductive layer;

wherein the second reflective layer is a reflective polymeric material that is electrically insulating, thermally insulating, and both light reflective and light permeable to re-reflect permeated light from the light emitter package via the underlying first reflective layer.

45. The method of claim 44, wherein the light emitter package comprises a layer of electrically conductive material, and wherein providing the first reflective layer comprises plating the first reflective layer directly over the layer of electrically conductive material.

46. The method of claim 44, wherein providing the second reflective layer comprises providing a reflective plastic that is disposed over the first reflective layer.

47. The method of claim 44, wherein providing the first reflective layer comprises providing a specularly reflective layer of metal.

48. The method of claim 44, wherein the light emitter package comprises a layer of electrically conductive material, and wherein providing the first reflective layer comprises plating a side wall of the electrically conductive material.

49. The method of claim 44, further comprising providing one or more light emitter chips over the substrate.