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; and
a bulb portion extending along the axis and attached to the base, the bulb portion comprising:
a strip comprising:
an elongate substrate having a uniform cross section extending from a first end to a second end opposite the first end, the elongate substrate comprising a top surface having a length extending between the first and second ends of the elongate substrate and a width perpendicular to the length, the length being greater than the width, the substrate comprising side surfaces on opposing sides of the width of the top surface;
a plurality of spaced-apart light-emitting diode (LED) unpackaged dies disposed on the top surface of the elongate substrate between the first and second ends, each of the LED unpackaged dies having a reflector arranged co-planar to the top surface and configured to reflect light from within the corresponding LED unpackaged die;
conductors arranged to provide electrical power to the LED unpackaged dies; and
a solid encapsulant encapsulating the LED unpackaged dies on the top surface of the substrate; and
an electrical connector connected to the strip and extending along a portion of one of the side surfaces of the elongate substrate, the electrical connector providing an electrical connection to the strip.
2. The solid state lamp of claim 1 , wherein the LED unpackaged dies comprise a first LED unpackaged die, and the conductors comprise a portion that electrically connects the electrical connector and the first LED unpackaged die.
3. The solid state lamp of claim 2 , wherein the portion comprises copper, gold or silver.
4. The solid state lamp of claim 2 , wherein a first surface of the electrical connector is in physical contact with the portion of one of the side surfaces of the elongate substrate, and the portion that electrically connects the electrical connector and the first LED unpackaged die is in physical contact with a second surface of the electrical connector, and the second surface is different from the first surface.
5. The solid state lamp of claim 4 , wherein the second surface of the electrical connector is parallel to the top surface.
6. The solid state lamp of claim 2 , wherein the portion that electrically connects the electrical connector and the first LED unpackaged die comprises a connection pad located at the first end of the substrate.
7. The solid state lamp of claim 6 , wherein the connection pad is located on the top surface of the substrate.
8. The solid state lamp of claim 2 , wherein the portion that electrically connects the electrical connector and the first LED unpackaged die is soldered to the electrical connector.
9. The solid state lamp of claim 2 , wherein the electrical connector is fastened to the elongate substrate without solder.
10. The solid state lamp of claim 2 , wherein the encapsulant comprises a mixture of a phosphor and a binder.
11. The solid state lamp of claim 10 , wherein the binder comprises a silicone.
12. The solid state lamp of claim 10 , wherein the mixture of a phosphor and a binder is in contact with the LED unpackaged dies and the top surface of the elongate substrate between the LED unpackaged dies, and the solid encapsulant provides an outside surface of each corresponding strip.
13. The solid state lamp of claim 1 , wherein the electrical connector protrudes beyond the top surface of the substrate.
14. The solid state lamp of claim 1 , wherein the substrate is a dielectric substrate.
15. The solid state lamp of claim 1 , wherein the electrical connector is connected to the first end of the substrate.
16. The solid state lamp of claim 15 , wherein, in each of the dies, the reflector is located adjacent the substrate.
17. The solid state lamp of claim 15 , wherein the electrical connector extends from the first side surface to the second side surface of the substrate.
18. The solid state lamp of claim 15 , wherein the LED unpackaged dies are arranged in two rows, the LED unpackaged dies in each row connected in series and the rows connected anti-parallel to each other.
19. The solid state lamp of claim 1 , wherein the electrical connector is a first electrical connector disposed at the first end of the substrate, and the solid state lamp further comprises a second electrical connector disposed at the second end of the substrate.
20. The solid state lamp of claim 19 , further comprising a support structure, wherein the strip is supported by the support structure.
21. The solid state lamp of claim 20 , wherein the support structure has a first portion and a second portion different from the first portion, the first electrical connector is attached to the first portion and the second electrical connector is attached to the second portion of the support structure; and wherein the support structure electrically connects the first and second electrical connectors to the base.
22. The solid state lamp of claim 21 , wherein the first portion of the support structure is disposed proximate the base and the second portion of the support structure is disposed distal of the base.
23. The solid state lamp of claim 20 , wherein the strip has a curved shape and the support structure maintains the curved shape of the strip.
24. The solid state lamp of claim 20 , wherein the strip is a straight strip.
25. The solid state lamp of claim 1 , wherein the reflector extends across a face of the corresponding LED unpackaged die.
26. The solid state lamp of claim 1 , wherein the substrate is a transmissive substrate.
27. 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.
28. The solid state lamp of claim 1 , wherein, during operation, the strip outputs first light in directions away from the top surface having a first spectral power distribution and the strip outputs second light in directions away from the bottom surface having a second spectral power distribution different from the first spectral power distribution.
29. The solid state lamp of claim 1 , wherein the encapsulant surrounding the LED unpackaged dies scatters light such that an intensity of light emitted in a first direction above the top surface of the strip differs from an intensity of a backscattered light emitted in a second direction opposite the first direction.
30. The solid state lamp of claim 1 , wherein the side surfaces of the substrate are free of the solid encapsulant.