Light-altering material arrangements for light-emitting devices
Solid-state lighting devices and more particularly light-emitting devices including light-emitting diodes (LEDs) with light-altering material arrangements are disclosed. LED devices may include light-altering materials that are provided around peripheral sidewalls of LED chips without the need for a supporting submount or lead frame. The light-altering materials may be provided with reduced thicknesses along peripheral sidewalls of LED chips. An exemplary LED device as disclosed herein may be configured with a footprint that is close to a footprint of the LED chip within the LED device while also providing an amount of light-altering material around peripheral edges of the LED chip to reduce cross-talk. Accordingly, such LED devices may be well suited for use in applications where LED devices form closely-spaced LED arrays. Fabrication techniques are disclosed that include laminating a preformed sheet of light-altering material on one or more surfaces of the LED chip.
1. A light-emitting diode (LED) device comprising:
at least one LED chip comprising a top face, a bottom face, and peripheral sidewalls that bound the top face and the bottom face;
a wavelength conversion element arranged on the top face of the at least one LED chip, the wavelength conversion element comprising at least one lumiphoric material; and
a light-altering material arranged on the peripheral sidewalls of the at least one LED chip, the light-altering material comprising a width as measured from the peripheral sidewalls that is in a range from 15 microns (μm) to 100 μm, wherein the light-altering material is further arranged to extend from the peripheral sidewalls of the at least one LED chip along peripheral side surfaces of the wavelength conversion element to a position that is adjacent a top face of the wavelength conversion element, wherein the top face of the at least one LED chip is devoid of the light-altering material.
2. The LED device of claim 1 , wherein the width of the light-altering material is in a range from 15 μm to 50 μm.
3. The LED device of claim 1 , wherein the bottom face of the at least one LED chip is devoid of the light-altering material.
4. The LED device of claim 1 wherein the light-altering material comprises a light-reflective material.
5. The LED device of claim 4 wherein the light-reflective material comprises fused silica, fumed silica, or titanium dioxide (TiO 2 ) particles suspended in silicone.
6. The LED device of claim 1 wherein the light-altering material comprises a light-absorbing material.
7. The LED device of claim 1 , wherein the LED device is devoid of a submount on the bottom face of the at least one LED chip.
8. The LED device of claim 1 , further comprising an anode and a cathode on the bottom face of the at least one LED chip.
9. The LED device of claim 1 , wherein the wavelength conversion element further comprises a superstrate that supports the at least one lumiphoric material.
10. The LED device of claim 1 , wherein the wavelength conversion element comprises one of a ceramic phosphor plate, phosphor-in-glass, or phosphor embedded in silicone.
11. The LED device of claim 1 , wherein the peripheral side surfaces of the wavelength conversion element are offset from the peripheral sidewalls of the at least one LED chip.
12. The LED device of claim 11 , wherein the light-altering material is conformal on the peripheral side surfaces of the wavelength conversion element and the peripheral sidewalls of the at least one LED chip.
13. The LED device of claim 1 , wherein the light-altering material forms rounded corners at peripheral edge corners of the wavelength conversion element.
14. The LED device of claim 1 , wherein the light-altering material forms rounded corners at peripheral sidewall corners of the at least one LED chip.
15. The LED device of claim 1 , wherein the light-altering material forms extensions that extend away from the peripheral sidewalls of the at least one LED chip.
16. The LED device of claim 1 , further comprising a lens on the at least one LED chip.
17. A light-emitting diode (LED) device comprising:
at least one LED chip comprising a top face, a bottom face, and peripheral sidewalls that bound the top face and the bottom face;
a light-altering material arranged on the peripheral sidewalls of the at least one LED chip, the light-altering material comprising a width as measured from the peripheral sidewalls that is in a range from 15 microns (μm) to 100 μm; and
a light-transmissive material arranged on the top face of the at least one LED chip, wherein the light-altering material is further arranged to extend along peripheral side surfaces of the light-transmissive material such that a top surface of the light-altering material is coplanar with a top surface of the light-transmissive material, and wherein the light-transmissive material comprises a lens that includes silicone, plastic, epoxy, or glass.
18. The LED device of claim 17 , wherein the light-altering material comprises a light-reflective material.
19. The LED device of claim 17 , wherein the light-altering material comprises a light-absorbing material.
20. The LED device of claim 17 , wherein the LED device is devoid of a submount on the bottom face of the at least one LED chip.
21. The LED device of claim 17 , wherein the light-transmissive material is a support element of a wavelength conversion element arranged on the top face of the at least one LED chip, the wavelength conversion element comprising at least one lumiphoric material.
22. The LED device of claim 21 , wherein the lumiphoric material comprises phosphor embedded in silicone.
23. The LED device of claim 21 , wherein peripheral side surfaces of the wavelength conversion element are offset from the peripheral sidewalls of the at least one LED chip.
24. The LED device of claim 23 , wherein the light-altering material is conformal on the peripheral side surfaces of the wavelength conversion element and the peripheral sidewalls of the at least one LED chip such that the light-altering material forms a curved transition between the peripheral side surfaces of the wavelength conversion element and the peripheral sidewalls of the at least one LED chip.