Passivation layer comprising a photocrosslinked fluoropolymer

Patent metadata

Field	Value
Publication number	US-10190015-B2
Application number	US-201515315697-A
Country	US
Kind code	B2
Filing date	May 27, 2015
Priority date	Jun 3, 2014
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

The present disclosure relates to a passivation layer comprising a photocrosslinked fluoropolymer and a process for forming the layer. Passivation layers comprising the crosslinked fluoropolymer have low dielectric constants, low water absorptivity and are able to be photoimaged so as to provide the very fine features needed for modern electronic equipment.

First claim

What is claimed is:

1. A passivation layer comprising a layer of a photocrosslinked coating composition disposed on at least a portion of a substrate, wherein the coating composition consists essentially of:
i) a photocrosslinkable fluoropolymer having repeat units comprising:
(a) a fluoroolefin;
(b) an alkyl vinyl ether wherein the alkyl group is a C1 to C6 straight or a C3 to C6 branched or cyclic saturated hydrocarbon radical; and
(c) a vinyl epoxide;

ii) a photoacid generator;
iii) an optional photosensitizer; and
iv) a carrier medium;
wherein the photocrosslinkable fluoropolymer has a number average molecular weight in the range of from 20,000 to 300,000, and, wherein the layer of photocrosslinked coating composition has a dielectric constant in the range of from 1 to 5 when measured at 100 kHz, and wherein the layer of the photocrosslinked coating composition having a thickness in the range of from 0.01 micrometers to 300 micrometers has photocrosslinked features having a minimum width that is the larger of a) about 10 percent the thickness of the coating composition or b) 0.5 micrometers.

2. The passivation layer of claim 1 , wherein the fluoroolefin is tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, trifluoroethylene, perfluoromethyl vinyl ether, vinyl fluoride, vinylidene fluoride, perfluorodimethyldioxole, trifluoropropylene, perfluoro(2-methylene-4-methyl-1,3-dioxolane, hexafluoroisobutylene, methyl 3-[1-[difluoro[(trifluorovinyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-2,2,3,3-tetrafluoropropionate, 2-[1-[difluoro[(1,2,2-trifluoroethenyl)oxy]methyl]-1,2,2,2-tetrafluoroethoxy]-1,1,2,2-tetrafluoro-ethanesulfonyl fluoride or a combination thereof; or wherein the alkyl vinyl ether is methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, sec-butyl vinyl ether, t-butyl vinyl ether, n-pentyl vinyl ether, isoamyl vinyl ether, hexyl vinyl ether, cyclohexyl vinyl ether or a combination thereof; or wherein the vinyl epoxide is allyl glycidyl ether, glycidyl methacrylate, or a combination thereof.

3. The passivation layer of claim 1 , wherein the photocrosslinked features have a width in the range of from 0.5 to 5.0 micrometers.

4. The passivation layer of claim 1 , wherein the carrier medium is methyl isobutyl ketone, 2-heptanone, propylene glycol methyl ether acetate or a combination thereof.

5. The passivation layer of claim 1 , wherein the layer of the photocrosslinked coating composition has a dielectric constant in the range of from 1.1 to 4.5 when measured at 100 kHz.

6. The passivation layer of claim 1 , wherein the layer of the photocrosslinked coating composition absorbs in the range of 0.01 to 1.0 percent by weight percent by weight of water when submerged in deionized water at a temperature in the range of from 20 to 22° C. for 24 hours.

7. The passivation layer of claim 1 , wherein the layer of the photocrosslinked coating has a thickness in the range of about 0.1 micrometers to about 50 micrometers.

8. The passivation layer of claim 1 , wherein the passivation layer is a layer of a thin film transistor, organic field effect transistor, semiconductor, semiconductor oxide field effect transistor, integrated circuit, light emitting diode, display device, flexible circuit, solder mask, photovoltaic device, printed circuit board, an interlayer dielectric, optical waveguide, a micro electromechanical system, a layer of an electronic display device or a layer of a microfluidic device or chip.

9. The passivation layer of claim 1 , wherein the layer is in the form of a patterned surface for electrowetting.

10. The passivation layer of claim 1 , wherein the photocrosslinked coating composition comprises in the range of about 80 to about 99.5 percent by weight of the photocrosslinkable fluoropolymer; from 0 to about 10 percent by weight of the photosensitizer; and from about 0.1 to about 10 percent by weight of the photoacid generator, wherein the percentages by weight are based on the total weight of the photocrosslinked coating composition.

11. The passivation layer of claim 1 , wherein the photosensitizer is 2-isopropyl-9H-thioxanthen-9-one, 4-isopropyl-9H-thioxanthen-9-one, 1-chloro-4-propoxythioxanthone, 2-isopropylthioxanthone, phenothiazine or a combination thereof.

12. The passivation layer of claim 1 , wherein the photoacid generator is (p-isopropylphenyl)(p-methylphenyl)iodonium tetrakis(pentafluorophenyl)borate, tris[4-(4-acetylphenyl)sulfanylphenyl]sulfonium tris(trifluoromethanesulfonyl)methide, bis(1,1-dimethylethylphenyl)iodonium salt with tris[(trifluoromethane)sulfonyl]methane or bis(4-decylphenyl)iodonium hexafluoroantimonate oxirane, 4,4′,4″-tris(t-butylphenyl)sulfonium triflate, 4,4′-di-t-butylphenyl iodonium triflate, diphenyliodonium tetrakis(pentafluorophenyl)sulfonium borate, triarylsulfonium-tetrakis(pentafluorophenyl) borate, triphenylsulfonium tetrakis(pentafluorophenyl) sulfonium borate, 4,4′-di-t-butylphenyl iodonium tetrakis(pentafluorophenyl) borate, tris(t-butylphenyl) sulfonium tetrakis(pentafluorophenyl) borate, 4-methylphenyl-4-(1-methylethyl)phenyl iodonium tetrakis(pentafluorophenyl) borate or a combination thereof.

13. A process comprising:
(1) providing a photocrosslinkable coating composition consisting essentially of:
i) a photocrosslinkable fluoropolymer comprising:
(a) a fluoroolefin;
(b) an alkyl vinyl ether wherein the alkyl group is a C1 to C6 straight or a C3 to C6 branched or cyclic saturated hydrocarbon radical;
(c) a vinyl epoxide; and
(d) optionally, other monomers; and

ii) a photoacid generator;
iii) an optional photosensitizer; and
iv) a carrier medium;

(2) applying a layer of the photocrosslinkable coating composition onto at least a portion of a substrate;
(3) removing at least a portion of the carrier medium;
(4) irradiating at least a portion of the layer of the photocrosslinkable coating composition with ultraviolet light;
(5) heating the applied layer of photocrosslinkable coating composition; and
(6) removing at least a portion of the uncrosslinked photocrosslinkable fluoropolymer;

wherein the photocrosslinkable fluoropolymer has a number average molecular weight in the range of from 20,000 to 300,000, and, wherein the layer of photocrosslinked coating composition has a dielectric constant in the range of from 1 to 5 when measured at 100 kHz, and wherein a layer of the photocrosslinked coating composition having a thickness in the range of from 0.01 micrometers to 300 micrometers has photocrosslinked features having a minimum width that is the larger of a) about 10 percent the thickness of the coating composition or b) 0.5 micrometers.

14. The process of claim 13 wherein the process further comprises the step of applying an adhesion promoter to at least a portion of the substrate prior to the step (2), applying a layer of the photocrosslinkable coating composition onto at least a portion of the substrate.

15. The process of claim 13 , wherein the photocrosslinkable coating composition comprises in the range of about 80 to about 99.5 percent by weight of the photocrosslinkable fluoropolymer; from 0 to about 10 percent by weight of the photosensitizer; and from about 0.5 to about 10 percent by weight of the photoacid generator, wherein the percentages by weight are based on the total weight of the photocrosslinked coating composition.

16. The process of claim 13 , wherein the fluoroolefin is tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, trifluoroethylene, perfluoromethyl vinyl ether, vinyl fluoride, vinylidene fluoride, pe

Assignees

• Chemours Co Fc Llc

Inventors

• Lloyd Ralph Birchard
• Ryley James F
• Wheland Robert Clayton
• Chung Sung Jin

Classifications

• C09D5/24

  Electrically-conducting paints {(conductive materials H01B1/00)} · CPC title

• G03F7/0046 Primary

  with perfluoro compounds, e.g. for dry lithography (G03F7/0048 takes precedence) · CPC title

• C09D127/20

  Homopolymers or copolymers of hexafluoropropene · CPC title

• C08J3/24

  Crosslinking, e.g. vulcanising, of macromolecules (mechanical aspects B29C35/00; crosslinking agents C08K) · CPC title

• C09D127/12

  containing fluorine atoms · CPC title