Clear coating for light emitting device exterior having chemical resistance and related methods
Light emitting devices and components having excellent chemical resistance and related methods are disclosed. In one embodiment, an LED device or package with an encapsulant material or lens disposed over at least a portion of the LED device or package and a poly(methyl) acrylate-silicon containing barrier coating at least partially disposed over the encapsulant or the lens provides corrosion protection to corrodible metals and/or moisture protection to moisture sensitive components.
1. An LED device comprising:
one or more LED chips;
an encapsulant material or lens disposed over at least a portion of the one or more LED chips; and
a barrier coating at least partially disposed over the encapsulant or lens, wherein the barrier coating comprises a polyacrylate-silicon containing material, a polymethylacrylate-silicon containing material, or mixtures thereof represented by Formula (1):
where R is methyl or ethyl or a C 3 -C 6 straight or branched alkyl; each R 1 is, independently, hydrogen, hydroxyl, alkyl, phenyl, or vinyl, with the proviso that at least one R 1 is hydrogen, hydroxyl, or vinyl; R 2 and R 3 are, independently, hydrogen, methyl, or ethyl; and x and y represent molar amounts of monomer, where 0<x+y≤1, and y>0 arranged as a block co-polymer, a random copolymer, a graft copolymer, or a silane end-terminated polymer.
2. The device of claim 1 , wherein the barrier coating is directly disposed on the encapsulant material or the lens.
3. The device of claim 1 , further comprising one or more corrodible metal components selected from silver (Ag), aluminum (Al), copper (Cu), or alloys thereof.
4. The device of claim 1 , further comprising a corrodible metal component comprising silver (Ag).
5. The device of claim 1 , further comprising one or more reflective metal components selected from silver (Ag), aluminum (Al), or alloys thereof.
6. The device of claim 5 , further comprising a reflective metal component comprising silver (Ag).
7. The device of claim 1 , wherein the LED device comprises an element or compound sensitive to moisture or water vapor.
8. The device of claim 7 , wherein the element or compound is a potassium fluorosilicate.
9. The device of claim 1 , wherein the barrier coating is a mixture of polymer structures represented by Formula (1), where at least one of the polymer structures represented by Formula (1) of the mixture has R 1 =hydrogen and at least one of the polymer structures represented by Formula (1) of the mixture has R 1 =vinyl.
10. The device of claim 1 , wherein the barrier coating is a polymer structure represented by Formula (1), where R 1 =hydroxyl.
11. The device of claim 4 , further comprising an additional layer deposited on at least a portion of the corrodible metal component, wherein the lens or the encapsulant is positioned between the additional layer and the barrier coating.
12. The device of claim 10 , wherein the additional layer comprises one or more reflective materials.
13. The device of claim 10 , wherein the additional layer is the same material as the barrier coating.
14. A method of reducing or preventing corrosion of corrodible metal components of an LED device, the method comprising:
applying a barrier coating to at least a portion of an encapsulant or lens of an LED device, the LED device having at least one corrodible metal portion, wherein the barrier coating comprises a polyacrylate-silicon containing material, a polymethylacrylate-silicon containing material, or mixtures thereof represented by Formula (1):
where R is methyl or ethyl or a C 3 -C 6 straight or branched alkyl; each R 1 is, independently, hydrogen, hydroxyl, alkyl, phenyl, or vinyl, with the proviso that at least one R 1 is hydrogen, hydroxyl, or vinyl; R 2 and R 3 are, independently, hydrogen, methyl, or ethyl; and x and y represent molar amounts of monomer, where 0<x+y≤1, and y>0 arranged as a block co-polymer, a random copolymer, a graft copolymer, or a silane end-terminated polymer; and
reducing or preventing permeation of one or more chemicals capable of corroding the at least one corrodible metal portion.
15. The method of claim 14 , wherein the barrier coating is applied directly to the encapsulant or the lens.
16. The method of claim 14 , further comprising reducing or preventing: a change of forward voltage (Vf) during operating conditions of the LED device or package; a change of luminosity during operating conditions of the LED device; or reducing or preventing a change of color shift during operating conditions during operating conditions of the LED device.
17. The method of claim 14 , wherein the corrodible metal portion comprises silver (Ag).
18. The method of claim 14 , wherein the corrodible metal portion comprises a reflective metal.
19. The method of claim 14 , wherein the reflective metal comprises silver (Ag).
20. The method of claim 14 , further comprising an additional layer positioned between the additional layer and the barrier coating, the additional layer reducing or preventing permeation of at least one of the one or more chemicals.
21. The method of claim 20 , wherein the additional layer comprises an amount of one or more reflective materials capable of reflecting light produced by the LED device.
22. The method of claim 20 , wherein the additional layer is the same material as the barrier coating.