Substrates for light emitting diodes and related methods
Light emitting diode (LED) devices, components and systems are provided. Improved substrates for LEDs and LED devices are provided, with one or more dielectric layers over a reflective layer sufficient to minimize or eliminate damage of the dielectric layer(s). More stable and efficient LED devices can be produced using such improved substrates. LED devices, and methods of making the same, are also provided wherein LED chips are embedded in fill material to attach the LEDs to a substrate and increase light reflectivity.
1. A substrate for a light emitting diode (LED), the substrate comprising:
an upper substrate surface;
a reflective layer disposed on the upper substrate surface; and
an encapsulating layer portion disposed over the reflective layer, the encapsulating layer portion having a thickness of at least about 100 nanometers (nm) to about 1 micron (um) to mitigate or eliminate damage of the encapsulating layer portion,
wherein the encapsulating layer portion comprises a distributed Bragg reflector or other non-metal reflective layer.
2. The substrate of claim 1 , wherein the encapsulating layer portion comprises two or more encapsulating layers that are different materials.
3. The substrate of claim 1 , wherein the encapsulating layer portion comprises multiple encapsulating layers of alternating materials.
4. The substrate of claim 1 , wherein the encapsulating layer portion comprises at least a first encapsulating layer and a second encapsulating layer disposed over the first encapsulating layer, and wherein the first encapsulating layer comprises a different material than the second encapsulating layer.
5. The substrate of claim 1 , wherein the encapsulating layer portion comprises at least a first encapsulating layer and a second encapsulating layer disposed over the first encapsulating layer, and wherein the first and second encapsulating layers are substantially a same thickness.
6. The substrate of claim 1 , wherein the encapsulating layer portion comprises at least a first encapsulating layer and a second encapsulating layer disposed over the first encapsulating layer, and wherein a thickness of the first encapsulating layer is different from a thickness of the second encapsulating layer.
7. The substrate of claim 1 , wherein the substrate is a metal substrate.
8. The substrate of claim 1 , wherein the reflective layer comprises a mirrored surface.
9. The substrate of claim 1 , wherein the reflective layer comprises silver (Ag).
10. The substrate of claim 1 , wherein the encapsulating layer portion comprises a dielectric layer that comprises silicon oxide, silicon nitride, aluminum oxide, titanium dioxide, non-metallic oxides, non-metallic nitrides, tantalum oxide, transparent conducting oxides, non-transparent materials or metals, or a combination thereof.
11. The substrate of claim 1 , wherein the encapsulating layer portion comprises at least a first encapsulating layer and a second encapsulating layer disposed over the first encapsulating layer.
12. The substrate of claim 11 , wherein the encapsulating layer portion comprises one or more additional encapsulating layers disposed above the first and second encapsulating layers.
13. The substrate of claim 12 , wherein at least two or more of the first, second and additional encapsulating layers have a different or same thickness.
14. The substrate of claim 1 , further comprising one or more LEDs disposed above the encapsulating layer portion.
15. The substrate of claim 14 , wherein the LEDs comprise top-side contact LEDs.
16. A substrate for a light emitting diode (LED), the substrate comprising:
an upper substrate surface;
a reflective layer disposed on the upper substrate surface; and
an encapsulating layer portion disposed over the reflective layer, the encapsulating layer portion having a thickness of at least about 100 nanometers (nm) to about 1 micron (um) to mitigate or eliminate damage of the encapsulating layer portion,
wherein the encapsulating layer portion comprises a distributed Bragg reflector or other non-metal reflective layer.
17. A light emitting diode (LED) device, comprising:
a substrate comprising an upper substrate surface;
a fill material at least partially covering the upper substrate surface; and
one or more top-side contact LEDs comprising an upper surface and lower surface, the LEDs disposed over the upper substrate surface and embedded in the fill material, wherein a layer of fill material is disposed under the lower surface of each of the one or more LEDs.
18. The LED device of claim 17 , wherein the fill material has a substantially uniform thickness.
19. The LED device of claim 17 , wherein the fill material has a thickness that extends to or proximate to an upper surface of the one or more LEDs.
20. The LED device of claim 17 , wherein the fill material comprises a molded shape in a space between the one or more LEDs.
21. The LED device of claim 20 , wherein the molded shape is a rounded ridge, a triangular ridge, a rectangular ridge, a half sphere or any combination thereof.
22. The LED device of claim 17 , wherein the fill material comprises a white fill material, a black fill material, a phosphor fill material, or any combination thereof.
23. The LED device of claim 22 , wherein the white fill material comprises TiO 2 or Al 2 O 3 .
24. The LED device of claim 22 , wherein the black fill material comprises Fe 3 O 4 .
25. The LED device of claim 22 , wherein the phosphor fill material comprises phosphor, a ceramic oxide, glass, any white, opaque, scattering, or reflective material, or a combination thereof.
26. A method of attaching a light emitting diode (LED) to a substrate, the method comprising:
providing a substrate comprising an upper substrate surface;
applying a fill material to the upper substrate surface;
applying one or more top-side contact LEDs to the substrate by placing the one or more LEDS into the fill material that is already applied to the upper substrate surface such that a portion of the fill material is disposed under each of the one or more LEDs; and
curing the fill material.
27. The method of claim 26 , comprising applying the one or more LEDs to the substrate wherein a layer of fill material is disposed between each of the one or more LEDs and the upper substrate surface.
28. The method of claim 27 , comprising applying the one or more LEDs to the substrate wherein the layer of fill material disposed between each of the one or more LEDs and the upper substrate surface has a thickness of about 1 um or less.
29. The method of claim 26 , wherein the fill material is partially or completely uncured prior to applying the one or more LEDs.
30. The method of claim 29 , wherein the fill material is cured using ultraviolet light or heat.
31. The method of claim 26 , wherein applying the fill material further comprises molding the fill material into one or more predetermined shapes and subsequently applying the LEDs in gaps between the molded shapes.
32. The method of claim 31 , wherein the one or more molded shapes comprise a rounded ridge, a triangular ridge, a rectangular ridge, a half sphere or any combination thereof.
33. The method of claim 26 , wherein the fill material comprises a white fill material, a black fill material, a phosphor fill material, or any combination thereof.
34. The method of claim 33 , wherein the white fill material comprises TiO 2 or Al 2 O 3 .
35. The method of claim 33 , wherein the black fill material comprises Fe 3 O 4 .
36. The method of claim 33 , wherein the phosphor fill material comprises phosphor, a ceramic oxide, glass, any white, opaque, scattering, or reflective material, or a combination thereof.