Light emitting device on a mount with a reflective layer
Embodiments of the invention include a semiconductor light emitting diode (LED) attached to a top surface of a mount. A multi-layer reflector is disposed on the top surface of the mount adjacent to the LED. The multi-layer reflector includes layer pairs of alternating layers of low index of refraction material and high index of refraction material. A portion of the top surface in direct contact with the multi-layer reflector is non-reflective.
1. A device comprising:
a mount comprising first and second metal pads disposed on a surface;
a semiconductor light emitting diode (LED) attached to a first portion of the first and second metal pads; and
a multi-layer reflector disposed on and in direct contact with a second portion of the first and second metal pads, the multi-layer reflector comprising layer pairs of alternating layers of low index of refraction material and high index of refraction material, wherein a portion of the surface is in direct contact with the multi-layer reflector and is non-reflective; and
a lens disposed over the LED and the multi-layer reflector.
2. The device of claim 1 wherein the first and second metal pads are selected from the group consisting of Cu, Al, and Au.
3. The device of claim 1 further comprising a layer disposed between the multi-layer reflector and the lens, wherein the layer has an index of refraction lower than the index of refraction of the lens.
4. The device of claim 3 wherein the layer has an index of refraction no more than 1.3.
5. The device of claim 3 wherein the layer is selected from the group consisting of glass, fluoride glass, MgF, porous material, and porous SiO 2 .
6. The device of claim 1 further comprising a wavelength converting material disposed in the lens.
7. The device of claim 1 wherein the multi-layer reflector comprises at least one polymer layer.
8. The device of claim 1 wherein the mount is selected from the group consisting of a ceramic structure, a plastic structure, a metal structure with one or more electrical isolation layers, and a lead frame.
9. The device of claim 1 wherein the lens is selected from the group consisting of a dome lens, a Fresnel lens, and a conformal, transparent sheet of material.
10. A device comprising:
a mount comprising first and second metal pads disposed on a surface;
a semiconductor light emitting diode (LED) attached to a first portion of the first and second metal pads; and
a layer disposed on and in direct contact with a second portion of the first and second metal pads, wherein the layer has an index of refraction lower than the index of refraction of the lens, wherein a portion of the surface is in direct contact with the layer and is non-reflective; and
a lens disposed over the LED and the layer.
11. The device of claim 10 wherein the first and second metal pads are selected from the group consisting of Cu, Al, and Au.
12. The device of claim 10 wherein the layer has an index of refraction no more than 1.3.
13. The device of claim 10 wherein the layer is selected from the group consisting of glass, fluoride glass, MgF, porous material, and porous SiO 2 .
14. The device of claim 10 further comprising a wavelength converting material disposed in the lens.
15. The device of claim 10 wherein the mount selected from the group consisting of a ceramic structure, a plastic structure, a metal structure with one or more electrical isolation layers, and a lead frame.
16. The device of claim 10 wherein the lens is selected from the group consisting of a dome lens, a Fresnel lens, and a conformal, transparent sheet of material.