Solid state lamp using light emitting strips
A solid state lamp includes a connector and a bulb portion with multiple strips.
1. A solid state lamp comprising:
a base configured to electrically connect the solid state lamp to a power source, the base defining an axis;
an envelope configured to transmit light, the envelope extending along the axis; and
a strip inside the envelope, the strip extending from a first end to a second end opposite the first end, the strip comprising:
a substrate extending from the first end to the second end comprising a top surface and an opposing bottom surface;
a plurality of bare light-emitting diode (LED) dies disposed on the top surface of the substrate between the first and second ends of the strip;
conductors arranged to provide electrical power to the bare LED dies; and
an encapsulant encapsulating the bare LED dies,
wherein the substrate comprises a side surface between the top surface and the bottom surface; and
a connector attached to the strip and covering a portion of the side surface of the substrate, the connector providing an electrical connection to the strip, and wherein the strip is supported and electrically connected at the first end.
2. The solid state lamp of claim 1 , wherein each of the bare LED dies has a reflector arranged perpendicular to the top surface of the substrate.
3. The solid state lamp of claim 1 , wherein each of the bare LED dies has a reflector arranged parallel to the top surface of the substrate.
4. The solid state lamp of claim 3 , wherein the reflector is arranged to reflect light from within the corresponding bare LED die in directions away from the top surface of the substrate.
5. The solid state lamp of claim 3 , wherein the reflector comprises an electrode of the corresponding bare LED die.
6. The solid state lamp of claim 1 , wherein each of the bare LED dies are flip-chip LED dies.
7. The solid state lamp of claim 1 , wherein the bare LED dies each have a wire bond pad on a face of the corresponding bare LED die facing away from the top surface of the substrate.
8. The solid state lamp of claim 1 , wherein each of the bare LED dies has a pair of electrodes on a face of the corresponding bare LED die facing away from the top surface of the substrate.
9. The solid state lamp of claim 1 , wherein the envelope comprises a reflective portion and an exit portion, the reflective portion arranged to reflect light from the strip toward the exit portion, and the solid state lamp is a directional solid state lamp that outputs light from the exit portion with a beam distribution narrower than a hemispherical distribution.
10. The solid state lamp of claim 9 , wherein the reflective portion is a curved reflective portion.
11. The solid state lamp of claim 10 , wherein the reflective portion comprises multiple facets.
12. The solid state lamp of claim 9 , wherein the solid state lamp is configured as a MR16, R30 or PAR38 lamp.
13. The solid state lamp of claim 9 , wherein the reflective portion is a diffusely reflective portion.
14. The solid state lamp of claim 9 , wherein the exit portion extends perpendicular to the axis of the base.
15. The solid state lamp of claim 9 , wherein the exit portion comprises a lens.
16. The solid state lamp of claim 1 , wherein the envelope is selected from multiple different envelopes configured to provide different light output patterns, and the solid state lamp is configured to couple with the different envelopes to provide corresponding light output patterns.
17. The solid state lamp of claim 16 , wherein the envelope is a replaceable envelope.
18. The solid state lamp of claim 1 , wherein the envelope is a bulb-shaped envelope.
19. The solid state lamp of claim 1 , wherein the encapsulant comprises a mixture of a phosphor and a binder.
20. The solid state lamp of claim 19 , wherein the binder comprises a silicone.
21. The solid state lamp of claim 19 , wherein the mixture of a phosphor and a binder is in contact with the bare LED dies.
22. The solid state lamp of claim 21 , wherein the mixture of a phosphor and a binder is in contact with the top surface of the substrate between the bare LED dies.
23. The solid state lamp of claim 22 , wherein the encapsulant provides an outside surface of the strip.
24. The solid state lamp of claim 19 , wherein a density of the phosphor varies within the mixture of the phosphor and the binder.
25. The solid state lamp of claim 19 , wherein a thickness of the encapsulant varies with distance from the bare LED dies.
26. The solid state lamp of claim 19 , further comprising a phosphor layer disposed on the bottom surface of the substrate.
27. The solid state lamp of claim 1 , wherein portions of the top surface are free of the encapsulant.
28. The solid state lamp of claim 1 , wherein the encapsulant on the top surface of the substrate provides a first light emission surface through which the strip outputs a first intensity of light during operation, and a side of the strip opposite the first light emission surface provides a second light emission surface through which the strip outputs a second intensity of light during operation, and the first intensity of light is higher than the second intensity of light.
29. The solid state lamp of claim 1 , wherein the top surface faces a first side of the strip and a bottom surface of the substrate opposite the top surface faces a second side of the strip, and the strip outputs first light from the first side having a first spectral power distribution (SPD) and outputs second light from the second side having a second SPD different from the first SPD.
30. The solid state lamp of claim 1 , wherein the substrate is a light-transmissive substrate.
31. The solid state lamp of claim 30 , wherein the light-transmissive substrate is a transparent substrate.
32. The solid state lamp of claim 1 , wherein the strip is supported at the first end only.
33. The solid state lamp of claim 1 , wherein the strip is further supported by the envelope.
34. The solid state lamp of claim 1 , wherein the strip is a free-standing strip electrically connected only at the first end.
35. The solid state lamp of claim 34 , wherein the free-standing strip comprises a plug-in connector configured to electrically connect and support the free-standing strip.
36. The solid state lamp of claim 1 , wherein the envelope is a clear envelope.
37. The solid state lamp of claim 1 , wherein the envelope comprises perforations.
38. The solid state lamp of claim 1 , wherein the strip is supported by leads.
39. The solid state lamp of claim 38 , wherein the leads comprise wires.
40. The solid state lamp of claim 1 , further comprising a first lead and a second lead both arranged at the first end of the strip.
41. The solid state lamp of claim 40 , wherein the first and second leads are connected to the base.
42. The solid state lamp of claim 1 , wherein the strip comprises a first terminal pad and a second terminal pad both arranged on the top surface of the substrate at the first end of the strip.
43. The solid state lamp of claim 42 , wherein the first and second terminal pads are electrically connected to the base.
44. The solid state lamp of claim 1 , wherein the power source provides a mains voltage and the solid state lamp is configured to provide the mains voltage directly to the strip.
45. The solid state lamp of claim 1 , wherein the strip extends along the axis of the base.
46. The solid state lamp of claim 1 , wherein the substrate has a thickness between 0.025 mm and 3 mm.
47. The solid state lamp of claim 1 , wherein the strip has a thickness of 1 cm or less.
48. The solid state lamp of claim 1 , wherein the strip is 1 to 2 mm thick.
49. The solid state lamp of claim 1 , wherein the strip has a width less than 5 mm.
50. The solid state lamp of claim 1 , wherein the strip has a length between 1 and 6 inches.
51. The solid state lamp of claim 1 , wherein a light emitting portion of the solid state lamp has a dimension in a range from 2 inches to 4 inches.
52. The solid state lamp of claim 1 , wherein the strip further comprises additional electrical components and the bare LED dies are electrically connected with the additional electrical components.
53. The solid state lamp of claim 1 , wherein the bare LED dies are arranged in multiple rows and the bare LED dies in the strip are electrically connected in series.
54. The solid state lamp of claim 1 , wherein the bare LED dies are arranged between some of the electrical conductors and the substrate.
55. The solid state lamp of claim 1 , wherein the bare LED dies are evenly spaced.
56. The solid state lamp of claim 1 , wherein the bare LED dies comprise first bare LED dies associated with a first bin and second bare LED dies associated with a second bin different from the first bin.
57. The solid state lamp of claim 56 , wherein the first bare LED dies have a spectral power distribution (SPD) with a first peak wavelength and the second bare LED dies have a SPD with a second peak wavelength that differs from the first peak wavelength by 4 nm or more.
58. The solid state lamp of claim 57 , wherein second peak wavelength differs from the first peak wavelength by 10 nm.
59. The solid state lamp of claim 1 , wherein the envelope comprises a phosphor.
60. The solid state lamp of claim 1 , wherein the substrate comprises copper or aluminum.
61. The solid state lamp of claim 1 , wherein the substrate is a dielectric substrate.
62. The solid state lamp of claim 1 , wherein the encapsulant is a solid encapsulant.
63. The solid state lamp of claim 1 , further comprising one or more additional strips.
64. The solid state lamp of claim 63 , wherein at least two of the strips are oriented so that their respective top surfaces face different directions.
65. The solid state lamp of claim 64 , wherein the strips output light having different color temperatures and are controlled by a driver to output a combined light over a range of color temperatures.
66. The solid state lamp of claim 65 , wherein the combined light tracks a color temperature of an incandescent bulb during dimming.
67. The solid state lamp of claim 1 , further comprising a driver electrically connecting the base and the strip.
68. The solid state lamp of claim 1 , wherein the strip is bidirectional.
69. The solid state lamp of claim 1 , wherein the solid state lamp is configured to provide 360 degrees of light emission.
70. The solid state lamp of claim 1 , wherein a light emitting portion of the solid state lamp has a dimension in a range from 2 inches to 4 inches.
71. The solid state lamp of claim 1 , wherein the bare LED dies each have a wire bond pad on a top surface of each respective bare LED die.
72. The solid state lamp of claim 1 , wherein the strip is electrically connected only at the first end.
73. The solid state lamp of claim 1 , wherein the bare LED dies are spaced-apart bare LED dies and the encapsulant encapsulates the bare LED dies on the top surface of the substrate.
74. The solid state lamp of claim 1 , wherein the base is a first base and the solid state lamp further comprises a second base arranged opposite the first base, and the first and second base electrically connect the solid state lamp to the power source.
75. The solid state lamp of claim 74 , wherein the first end of the strip is arranged at the first base and the second base is arranged at the second end of the strip.