Lighting device having a patterned conformal coating doped with a luminescent material

1. A lighting device, comprising:

a substrate;

two or more light-emitting elements formed over the substrate;

a first transparent conformal layer formed over the two or more light-emitting elements in a pattern, the first transparent conformal layer being doped with a luminescent material;

a second transparent conformal layer formed over a portion of the substrate not covered by the two or more light-emitting elements, the second transparent conformal layer not being doped with the luminescent material.

2. The lighting device, of claim 1 , wherein

the luminescent material is remote phosphor.

3. The lighting device, of claim 1 , wherein

the first transparent conformal layer is contiguous.

4. The lighting device, of claim 1 , wherein

the luminescent material doped in the first transparent conformal converts an incoming wavelength of incoming light from the two or more light-emitting elements to an outgoing wavelength different from the incoming wavelength.

5. The lighting device, of claim 1 , wherein

the first transparent conformal layer has a thickness between 0.1 micron to 10 millimeters.

6. The lighting device, of claim 1 , wherein

the first transparent conformal layer comprises polyurethane, silicone, or acrylic having a refractive index between 1.7 and 2.1.

7. The lighting device, of claim 1 , wherein

the pattern is one of: a circle, a square, a triangle, a line, or an arrow.

8. The lighting device, of claim 1 , further comprising

a transparent affixing layer formed between the first and second transparent conformal layers and the substrate, the transparent affixing layer surrounding the two or more light-emitting elements.

9. The lighting device, of claim 1 , wherein

at least one of the first and second transparent conformal layers is made of a flame retardant material.

10. The lighting device, of claim 1 , wherein

the two or more light-emitting elements are two or more light-emitting diodes, and

each corresponding light-emitting diode of the two or more light-emitting diodes has a pair of electrodes formed on a same side of the corresponding light-emitting diode.

11. The lighting device, of claim 1 , wherein

the two or more light-emitting elements are two or more light-emitting diodes, and

each corresponding light-emitting diode of the two or more light-emitting diodes has a pair of electrodes formed on different sides of the corresponding light-emitting diode.

12. The lighting device, of claim 1 , wherein

the two or more light-emitting elements include a first light-emitting element and a second light-emitting element,

the first light-emitting element is configured to emit light in a first direction, and

the second light-emitting element is configured to emit light in a second direction different from the first direction.

13. The lighting device, of claim 1 , wherein

the first direction is toward the first transparent conformal layer, and

the second direction is toward the substrate.

14. A method of forming a lighting device, comprising:

providing a substrate;

forming two or more light-emitting elements over the substrate;

forming a first transparent conformal layer over the two or more light-emitting elements in a pattern, the first transparent conformal layer being doped with a luminescent material;

forming a second transparent conformal layer over a portion of the substrate not covered by the two or more light-emitting elements, the first transparent conformal layer not being doped with the luminescent material.

15. The lighting device, of claim 14 , wherein

the luminescent material is remote phosphor.

16. The lighting device, of claim 14 , wherein

the first transparent conformal layer is contiguous.

17. The lighting device, of claim 14 , wherein

the luminescent material doped in the first transparent conformal converts an incoming wavelength of incoming light from the two or more light-emitting elements to an outgoing wavelength different from the incoming wavelength.

18. The lighting device, of claim 14 , wherein

the first transparent conformal layer has a thickness between 0.1 micron to 10 millimeters.

19. The lighting device, of claim 14 , wherein

the first transparent conformal layer comprises polyurethane, silicone, or acrylic having a refractive index between 1.7 and 2.1.

20. The lighting device, of claim 14 , wherein

the pattern is one of: a circle, a square, a triangle, a line, or an arrow.

21. The lighting device, of claim 14 , further comprising

forming a transparent affixing layer between the first and second transparent conformal layers and the substrate, the transparent affixing layer surrounding the two or more light-emitting elements.

22. The lighting device, of claim 14 , wherein

at least one of the first and second transparent conformal layers is made of a flame retardant material.

23. The lighting device, of claim 14 , wherein

the two or more light-emitting elements are two or more light-emitting diodes, and

each corresponding light-emitting diode of the two or more light-emitting diodes has a pair of electrodes formed on a same side of the corresponding light-emitting diode.

24. The lighting device, of claim 14 , wherein

the two or more light-emitting elements are two or more light-emitting diodes, and

each corresponding light-emitting diode of the two or more light-emitting diodes has a pair of electrodes formed on different sides of the corresponding light-emitting diode.

25. The lighting device, of claim 14 , wherein

the two or more light-emitting elements include a first light-emitting element and a second light-emitting element,

the first light-emitting element is configured to emit light in a first direction, and

the second light-emitting element is configured to emit light in a second direction different from the first direction.

26. The lighting device, of claim 14 , wherein

the first direction is toward the first transparent conformal layer, and

the second direction is toward the substrate.