JP2023126253A - Photosensitive resin composition - Google Patents

Abstract

To provide a photosensitive resin composition which can be cured at a low temperature, is excellent in sensitivity and residual film ratio, and is excellent in residue characteristics.SOLUTION: The photosensitive resin composition according to one embodiment of the present invention contains 0.1-20 pts.wt. of a radical photoinitiator, 0.1-10 pts.wt. of an ionic photoinitiator, 1-50 pts.wt. of a polyfunctional acrylate oligomer, and 1-50 pts.wt. of a polyfunctional monomer having an ethylenically unsaturated bond based on 100 pts.wt. of an acrylic copolymer and contains a solvent.SELECTED DRAWING: Figure 4

Description

The present invention relates to a photosensitive resin composition, and more particularly, to a photosensitive resin composition that is curable at low temperatures, has excellent sensitivity, film retention rate, and excellent residue characteristics.

Generally, display devices are currently widely used, and there are various types such as liquid crystal displays (LCDs) and organic light emitting displays (OLEDs). Furthermore, recently, display devices that are bent to form a curved surface have been attracting attention, which improves the user's sense of immersion.

In the process of forming such a display device, a photo process is used to pattern a film, and at this time, a photoresist material is used. Alternatively, the film can be formed directly by exposing and developing the photoresist material.

Such photoresists are used to form insulating films, column spacers, overcoat layers, and color filter layers, but the resolution, adhesive strength, and residual film rate vary depending on the composition of the photosensitive resin composition used to form the photoresists. etc.

Japanese Patent Application Publication No. 2018-127621

An object of the present invention is to provide a photosensitive resin composition that can be cured at low temperatures, has excellent sensitivity, residual film rate, and excellent residue characteristics, and a pattern forming method using the same.

A photosensitive resin composition according to an embodiment of the present invention includes 0.1 to 20 parts by weight of a radical photoinitiator, 0.1 to 10 parts by weight of an ionic photoinitiator, based on 100 parts by weight of an acrylic copolymer. Contains 1 to 50 parts by weight of a polyfunctional acrylate oligomer, 1 to 50 parts by weight of a polyfunctional monomer having an ethylenically unsaturated bond, and a solvent.

The photosensitive resin composition can be cured at a temperature of 90° C. or lower.

The radical photoinitiator is 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione, or 2-(O-acetyloxime)-1-[4-( phenylthio)phenyl]-1,2-octanedione.

The ionic photoinitiator is phenyl(4-methoxyphenyl)iodonium phosphorus hexafluoride, N,N-dimethyl-N-benzyltrifluoromethanesulfonic acid, 4-methylphenyl(4-(2-methylpropylphenyl))iodonium It may be one or more selected from the group consisting of phosphorus hexafluoride, phenyl(4-methoxyphenyl)iodonium, and arsenic hexafluoride.

The content ratio of the radical photoinitiator and the ionic photoinitiator may be 2:1 to 1:2.

The solid content of the photosensitive resin composition may be 10% by weight to 50% by weight.

The photosensitive resin composition may further include a melamine crosslinking agent.

The photosensitive resin composition may further include a silane coupling agent.

The acrylic copolymer is formed by copolymerizing an unsaturated carboxy compound and an unsaturated olefin compound.

The solvent may have a boiling point of less than 150°C.

A pattern forming method according to an embodiment of the present invention includes the steps of coating a photosensitive resin composition on a substrate, and heating the coated photosensitive resin composition to a temperature of 75° C. to 85° C. , exposing and developing the coated photosensitive resin composition, and secondarily heating the developed photosensitive resin composition to a temperature of 80° C. to 90° C., For 100 parts by weight of acrylic copolymer, 0.1 to 20 parts by weight of radical photoinitiator, 0.1 to 10 parts by weight of ionic photoinitiator, 1 to 50 parts by weight of polyfunctional acrylate oligomer, and ethylene. Contains 1 to 50 parts by weight of a polyfunctional monomer having a polyunsaturated bond, and a solvent.

Gas within the photosensitive resin composition can be removed by the primary heating, and the photosensitive resin composition can be cured by the secondary heating.

The primary heating is performed for 1 to 5 minutes.

The secondary heating is performed for 30 minutes to 240 minutes.

The radical photoinitiator is 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione, or 2-(O-acetyloxime)-1-[4-( phenylthio)phenyl]-1,2-octanedione.

The ionic photoinitiator is phenyl(4-methoxyphenyl)iodonium phosphorus hexafluoride, N,N-dimethyl-N-benzyltrifluoromethanesulfonic acid, 4-methylphenyl(4-(2-methylpropylphenyl))iodonium It may be one or more selected from the group consisting of phosphorus hexafluoride, phenyl(4-methoxyphenyl)iodonium, and arsenic hexafluoride.

The content ratio of the radical photoinitiator and the ionic photoinitiator may be 2:1 to 1:2.

The solid content of the photosensitive resin composition may be 10% by weight to 50% by weight.

The photosensitive resin composition may further include a melamine crosslinking agent.

The photosensitive resin composition may further include a silane coupling agent.

The photosensitive resin composition according to the present example and the pattern forming method using the same have excellent sensitivity and film retention rate, improved residue characteristics, and excellent adhesive strength and chemical resistance in a low-temperature process.

1 is a process flowchart showing a pattern forming method according to an embodiment of the present invention. 1 is a process flowchart showing a pattern forming method according to an embodiment of the present invention. 1 is a process flowchart showing a pattern forming method according to an embodiment of the present invention. 1 is a process flowchart showing a pattern forming method according to an embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily implement them. The invention can be implemented in a variety of different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, unnecessary parts will be omitted, and the same or similar components will be denoted by the same reference numerals throughout the specification.

Further, the size and thickness of each component shown in the drawings are shown arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is shown in the drawings. In the drawings, the thickness of various layers and regions are exaggerated for clarity. In the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

Also, when we say that a layer, film, region, plate, etc. is ``above'' another part, we are not only saying that it is ``directly on'' that other part, but also that there are other parts in between. Including cases where there is. Conversely, when one part is referred to as being "directly on" another part, there are no intervening parts. Furthermore, being "above" a reference point means being above or below the reference point, and does not necessarily mean being "above" the reference point in the opposite direction of gravity. .

In addition, throughout the specification, when a part is said to "include" a certain component, this does not mean excluding other components, unless there is a specific statement to the contrary, but it does not mean that other components can be further included. means.

First, a photosensitive resin composition according to an example of the present invention will be described. A photosensitive resin composition according to an embodiment of the present invention includes 0.1 to 20 parts by weight of a radical photoinitiator, 0.1 to 10 parts by weight of an ionic photoinitiator, based on 100 parts by weight of an acrylic copolymer. Contains 1 to 50 parts by weight of a polyfunctional acrylate oligomer, 1 to 50 parts by weight of a polyfunctional monomer having an ethylenically unsaturated bond, and a solvent.

That is, the photosensitive resin composition according to an embodiment of the present invention simultaneously contains a radical photoinitiator and an ionic photoinitiator. Therefore, it can be cured even at a low temperature of 90°C or lower, and exhibits excellent adhesive strength and chemical resistance even when cured at a temperature of 90°C or lower. The photosensitive resin composition according to this example is a negative photosensitive resin composition in which the exposed portion is cured and remains, and the unexposed portion is removed.

Usually, a temperature of 200°C or higher is required for curing a photosensitive resin composition. However, when a photosensitive resin composition is applied to an insulating film of a touch panel integrated with a display device, the high temperature of 200°C or higher necessary for curing the photosensitive resin composition is The properties of the light emitting layer change. Therefore, a photosensitive resin composition that hardens at a high temperature of 200°C or higher cannot be applied to an insulating film that is formed in a continuous process with the light-emitting layer; the insulating film is manufactured in a separate process and then laminated. A process is required.

However, since the photosensitive resin composition according to the present example contains a radical photoinitiator and an ionic photoinitiator at the same time, it can be cured even at a low temperature of 90°C or lower, and therefore can be manufactured in a continuous process with the light emitting layer. Can be used as an insulating film. Therefore, the number of masks can be reduced in the manufacturing process.

Furthermore, since the insulating film produced using the photosensitive composition of this example is an organic film, it is more suitable for application to flexible display devices than existing insulating films containing inorganic substances. Furthermore, chemical vapor deposition (CVD), dry etching, stripping processes, etc. required in existing manufacturing processes for insulating films containing inorganic materials can be omitted.

The reason why the photosensitive resin composition of the present invention can be cured at a temperature of 90° C. or lower is that it simultaneously contains a radical photoinitiator and an ionic photoinitiator. In other words, in order for the curing reaction to occur, the benzene ring structure must be opened while the bonds in the benzene ring are broken, but both radical photoinitiators and ionic photoinitiators play the role of breaking the benzene ring, increasing the number of reaction sites. This is because the reaction can be actively carried out even at lower temperatures.

At this time, the content ratio of the radical photoinitiator and the ionic photoinitiator may be about 2:1 to 1:2. This is a numerical range that can maximize the adhesive strength and chemical resistance of the cured photosensitive resin composition during low-temperature curing.

In the photosensitive resin composition according to an embodiment of the present invention, the acrylic copolymer prevents the generation of residue during development and allows a pattern to be easily formed.

The acrylic copolymer is formed by copolymerizing an unsaturated carboxy compound and an unsaturated olefin compound. Specifically, the acrylic copolymer is
i) an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a mixture thereof;
ii) After synthesizing an olefinically unsaturated compound as a monomer and performing a radical reaction in the presence of a solvent and a polymerization initiator, unreacted monomers are removed through precipitation, filtration, and vacuum drying. Obtainable.

The unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides, or mixtures thereof used in the present invention include unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid, maleic acid, fumaric acid, citraconic acid, methaconic acid, Unsaturated dicarboxylic acids such as itaconic acid or anhydrides of these unsaturated dicarboxylic acids may be used alone or in combination of two or more. In particular, acrylic acid, methacrylic acid, or maleic acid is preferable because it has excellent copolymerization reactivity and solubility in an aqueous alkaline developer solution.

The unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, or a mixture thereof is preferably contained in an amount of 5 to 40 parts by weight based on 100 parts by weight of the total monomer. When the content is less than 5 parts by weight, there is a problem that it is difficult to dissolve in an alkaline aqueous solution, and when it exceeds 40 parts by weight, there is a problem that the solubility in an alkaline aqueous solution becomes excessively large.

The olefinically unsaturated compounds used in the present invention include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, methyl acrylate, isopropyl acrylate, cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, Cyclopentenyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl methacrylate, dicyclopentanyl methacrylate, 1-adamantyl acrylate, 1-adamantyl methacrylate, dicyclopentanyloxyethyl methacrylate, isobornyl methacrylate, cyclohexyl acrylate, 2-methyl Cyclohexyl acrylate, dicyclopentanyloxyethyl acrylate, isobornyl acrylate, phenyl methacrylate, phenyl acrylate, benzyl acrylate, 2-hydroxyethyl methacrylate, styrene, σ-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene , p-methoxystyrene, 1,3-butadiene, isoprene, or 2,3-dimethyl 1,3-butadiene, glycidyl acrylate, glycidyl methacrylate, α-ethyl glycidyl acrylate, α-n-propyl glycidyl acrylate, α-n-Butylglycidyl acrylate, β-methylglycidyl acrylate, β-methylglycidyl methacrylate, β-ethylglycidyl acrylate, β-ethylglycidyl methacrylate, 3,4-epoxybutyl acrylate , 3,4-epoxybutyl methacrylate, 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl methacrylate, 6,7-epoxyheptyl α-ethyl acrylate, o-vinylbenzyl glycidyl ether , m-vinylbenzylglycidyl ether, p-vinylbenzylglycidyl ether, and 3,4-epoxycyclohexyl methacrylate, and use the above compounds alone or in a mixture of two or more. do.

The olefinically unsaturated compound is preferably contained in an amount of 60 to 95 parts by weight based on 100 parts by weight of the total monomer. When the content is less than 60 parts by weight, there is a problem that resolution and heat resistance are reduced, and when it exceeds 95 parts by weight, there is a problem that the acrylic copolymer is difficult to dissolve in the alkaline aqueous solution of the developer. There is.

A monomer containing an epoxy group is used as the olefinically unsaturated compound. These monomers further enhance heat resistance, chemical resistance, and physical properties by forming a dense structure through a crosslinking reaction using an ionic photoinitiator during a low-temperature curing process.

Solvents used to solution polymerize such monomers include methanol, tetrahydroxyfuran, toluene, dioxane, and the like.

A radical polymerization initiator is used as a polymerization initiator for solution polymerizing such monomers, and specifically, 2,2-azobisisobutyronitrile, 2,2-azobisisobutyronitrile, etc. (2,4-dimethylvaleronitrile), 2,2-azobis(4-methoxy2,4-dimethylvaleronitrile), 1,1-azobis(cyclohexane-1-carbonitrile), or dimethyl 2,2'-azo Use bisisobutyrate etc.

An acrylic copolymer is produced by subjecting such monomers to a radical reaction in the presence of a solvent and a polymerization initiator, and removing unreacted monomers through precipitation, filtration, and vacuum drying steps. Such an acrylic copolymer may have a polystyrene equivalent weight average molecular weight (Mw) of 3,000 to 30,000. If the polystyrene equivalent weight average molecular weight is less than 3,000, developability, residual film rate, etc. may be reduced, and pattern development and heat resistance may be reduced; if it exceeds 30,000, pattern development may be impaired. It may be inferior.

The photoinitiator used in the photosensitive resin composition of the present invention includes one or more radical photoinitiators and one or more ionic photoinitiators.

Examples of the radical photoinitiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, p-dimethylaminoacetophenone, and 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane. -1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4- Acetophenone compounds such as morpholinophenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone , benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin compounds such as benzyl dimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl -4'-methyldiphenyl sulfide, benzophenone compounds such as 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2 , 4-diisopropylthioxanthone, 2,4-diethylthioxanthone and other thioxanthone compounds, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2- (p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-piperonyl-4,6 -bis(trichloromethyl)-s-triazine, 2,4-bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphth-1-yl)-4,6-bis(trichloromethyl)-s -triazine, 2-(4-methoxy-naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine, 2,4- Triazine compounds such as trichloromethyl(4'-methoxystyryl)-6-triazine, 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione, 1-(O -acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethanone, O-ethoxycarbonyl-α-oxyamino-1-phenylpropan-1-one , 1,2-octanedione, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, 1-(4-phenylsulfanylphenyl) )-butane-1,2-dione-2-oxime-O-benzoate, 1-(4-phenylsulfanylphenyl)-octane-1,2-dione-2-oxime-O-benzoate, 1-(4-phenyl Sulfanylphenyl)-octan-1-one oxime-O-acetate, 1-(4-phenylsulfanylphenyl)-butan-1-one oxime-O-acetate, 2-(O-benzoyloxime)-1-[4-(phenylthio) )p-methylphenyl]-1,2-octanedione, 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-phenyldione, 2-(O-acetyloxime)- 1-[4-(phenylthio)phenyl]-1,2-octanedione, 2-(O-acetyloxime)-1-[4-(phenylthio)phenyl]-1,2-phenyldione, 2-(O- acetyloxime)-1-[4-(phenylthio)phenyl]-1,2-methyldione, O-(acetyl)-N-(1-phenyl-2-oxo-2-(4'-methoxy-naphthyl)ethylidene) ) Oxime ester compounds such as hydroxylamine, phosphine compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,2'-bis (o-chlorophenyl)-4,5,4',5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(o-methoxyphenyl)-4,4',5,5'- Imidazole compounds such as tetraphenylbiimidazole, 2,2'-bis(o-methoxyphenyl)-4,4',5,5'-tetra(p-methylphenyl)biimidazole, 9,10-phenanthrenequinone, Quinone compounds such as camphorquinone and ethyl anthraquinone, borate compounds, carbazole compounds, titanocene compounds, etc. are used, and these are used alone or in combination of two or more.

The content of the radical photoinitiator is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the acrylic copolymer. If the content of the radical photoinitiator is less than 0.1 part by weight, the remaining film rate will be poor due to low sensitivity, and if it exceeds 20 parts by weight, there will be problems such as poor developability and reduced resolution. be.

The ionic photoinitiators include cationic photoinitiators and anionic photoinitiators. Cationic photoinitiators include onium salts such as sulfonium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts, benzothiazolium salts, sulfoxonium salts, and ferrocene compounds. Other examples include, but are not limited to, nitrobenzyl sulfonates, alkyl or allyl-N-sulfonyloxyimides, halogenated alkyl sulfonate esters, and oxime sulfonates.

By way of example, cationic photoinitiators include tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, tetrabutylammonium hydrogen sulfate, tetraethylammonium tetrafluoroborate, tetraethylammonium, p-toluenesulfonate, N,N- Dimethyl-N-benzylanilinium antimony hexafluoride, N,N-dimethyl-N-benzylanilinium boron tetrafluoride, N,N-dimethyl-N-benzylpyridinium antimony hexafluoride, N,N-dimethyl-N -Benzyltrifluoromethanesulfonic acid, N,N-dimethyl-N-(4-methoxybenzyl)pyridinium antimony hexafluoride, N,N-dimethyl-N-(4-methoxybenzyl)toluidinium antimony hexafluoride, ethyltriphenyl Phosphonium antimony hexafluoride, tetrabutylphosphonium antimony hexafluoride, triphenylsulfonium boron tetrafluoride, triphenylsulfonium antimony hexafluoride, triphenylsulfonium arsenic hexafluoride, tri(4-methoxyphenyl)sulfonium arsenic hexafluoride , diphenyl(4-phenylthiophenyl)sulfonium arsenic hexafluoride, diphenyliodonium arsenic hexafluoride, di-4-chlorophenyliodonium arsenic hexafluoride, di-4-bromphenyliodonium arsenic hexafluoride, phenyl(4-methoxy phenyl)iodonium arsenic hexafluoride, diphenyliodonium phosphorus hexafluoride, di-4-chlorophenyliodonium phosphorus hexafluoride, di-4-bromphenyliodonium phosphorus hexafluoride, phenyl(4-methoxyphenyl)iodonium phosphorus hexafluoride , 4-methylphenyl(4-(2-methylpropylphenyl))iodonium phosphorus hexafluoride, di-4-tetraphenyliodonium phosphorus hexafluoride, diphenyliodonium phosphorus hexafluoride, di-4-tetraphenyliodonium hexafluoride It may be one or more selected from the group consisting of antimony chloride, diphenyliodonium hexafluoride, 4-methylphenyl(4-(2-methylpropylphenyl))iodonium arsenic tetrafluoride, but is limited to Not that it will be done.

The anionic photoinitiator may be one or more selected from the group consisting of benzoin carbamate, dimethylbenzyloxycarbamoylamine, o-acyl oxime, o-nitrobenzoin carbamate, formanilide derivative, and α-ammonium acetophenone. Good, but not limited to this.

The content of the ionic photoinitiator may be 0.1 to 10 parts by weight based on 100 parts by weight of the acrylic copolymer. If the content of the ionic photoinitiator is less than 0.1 part by weight, the chemical resistance will deteriorate due to a low degree of curing, and if it exceeds 10 parts by weight, a residue will be generated due to the excessive degree of curing, resulting in poor resolution. may decrease.

The polyfunctional acrylate oligomer contained in the photosensitive resin composition according to this example has 2 to 20 functional groups. For example, aliphatic urethane acrylate oligomers, aromatic urethane acrylate oligomers, epoxy acrylate oligomers, epoxy methacrylate oligomers, polyester acrylate oligomers, silicone acrylate oligomers, melamine acrylate oligomers, tendritic acrylate oligomers, etc. are used alone or Use a mixture of two or more.

The content of the polyfunctional acrylate oligomer is preferably 1 to 50 parts by weight based on 100 parts by weight of the acrylic copolymer. If the content of the polyfunctional acrylate oligomer is less than 1 part by weight, there is a problem that the remaining film rate will be poor due to low sensitivity, and if it exceeds 50 parts by weight, developability will be poor and resolution will decrease. There is.

Further, the polyfunctional monomer having an ethylenically unsaturated bond contained in the photosensitive resin composition according to an embodiment of the present invention is 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, ethylene glycol Diacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, dipentaerythritol hexadiacrylate, dipentaerythritol tridiacrylate, diacrylate Pentaerythritol diacrylate, sorbitol triacrylate, bisphenol A diacrylate derivatives, dipentaerythritol polyacrylate, methacrylates thereof, and the like are used alone or in combination of two or more thereof.

The content of the polyfunctional monomer having an ethylenically unsaturated bond may be 1 to 50 parts by weight based on 100 parts by weight of the acrylic copolymer. If the content is less than 1 part by weight, the residual film rate will be poor due to low sensitivity, and if it exceeds 50 parts by weight, developability may be poor and resolution may be reduced.

The solvent used in the photosensitive resin composition according to an embodiment of the present invention is not limited, but may have a boiling point of less than 150°C, for example. When a solvent with a boiling point of less than 150° C. is used as described above, residual solvent in a low temperature process can be minimized and chemical resistance can be ensured.

By way of example, the solvent may include esters such as methyl-2-hydroxyisobutyrate, ethylene glycol methyl ether acetate, 2-methoxy-1-methyl ethyl ester, propylene acetate, ethyl propionate, ethyl pyruvate, 1- From the group consisting of ethers such as methoxy-2-propanol, dibutyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol dimethyl ether, and tetrahydrofuran, and alcohols such as methanol, ethanol, and isopropyl alcohol, each It is preferable to select and use one or more types in consideration of reactivity with components and ease of forming a coating film.

The solvent is preferably included in the entire photosensitive resin composition so that the solid content is 10 to 50% by weight. The composition having a solid content within the above range is used after being filtered through a 0.1 to 0.2 μm Millipore filter. Further, as an example, the content of the solvent in the photosensitive resin composition may be in a range such that the solid content is 15 to 40% by weight.

When the solid content of the photosensitive resin composition is less than 10% by weight, there is a problem that the coating thickness becomes thin and the flatness of the coating decreases; when it exceeds 50% by weight, the coating thickness decreases. The coating may become thicker, straining the coating equipment during coating, and residual solvent may increase.

Furthermore, the photosensitive composition according to this example may further include a melamine crosslinking agent. Melamine crosslinkers improve the heat resistance, chemical resistance and adhesive strength of photosensitive compositions.

As the melamine crosslinking agent, a condensation product of urea and formaldehyde, a condensation product of melamine and formaldehyde, or methylol urea alkyl ethers and methylol melamine alkyl ethers obtained from alcohol are used.

Specifically, monomethylol urea, dimethylol urea, etc. are used as the condensation product of urea and formaldehyde. As the condensation product of melamine and formaldehyde, hexamethylol melamine is used, and partial condensation products of melamine and formaldehyde can also be used.

The methylol urea alkyl ethers are those obtained by reacting a condensation product of urea and formaldehyde with an alcohol on part or all of the methylol group, and specific examples include monomethyl urea methyl ether, dimethyl urea Use methyl ether etc. The methylol melamine alkyl ethers are those obtained by reacting a condensation product of melamine and formaldehyde with an alcohol on part or all of the methylol group, and specific examples include hexamethylol melamine hexamethyl ether, hexamethylol Use melamine hexabutyl ether, etc. Furthermore, compounds with a structure in which the hydrogen atom of the amino group of melamine is substituted with a hydroxymethyl group and a methoxymethyl group, and compounds with a structure in which the hydrogen atom of the amino group of melamine are substituted with a butoxymethyl group and a methoxymethyl group are also used. It is possible, and it is particularly preferred to use methylolmelamine alkyl ethers.

The content of the melamine crosslinking agent may be 0.1 to 20 parts by weight based on 100 parts by weight of the acrylic copolymer.

Furthermore, the photosensitive composition according to this example may further include a silane coupling agent. The silane coupling agent improves the adhesive strength of the photosensitive composition with the lower substrate. The silane coupling agent includes (3-glycidoxypropyl)trimethoxysilane, (3-glycidoxypropyl)triethoxysilane, (3-glycidoxypropyl)methyldimethoxysilane, (3-glycidoxypropyl) ) Methyldiethoxysilane, (3-glycidoxypropyl)dimethylethoxysilane, 3,4-epoxybutyltrimethoxysilane, 3,4-epoxybutyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltri Methoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, 3-triethoxysilane-N-(1,3dimethyl-butylidene)propylamine, N -2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, N-2(aminoethyl)3-aminopropylmethyldimethoxysilane, N-phenyl-3- Aminopropyltrimethoxysilane or (3-isocyanatepropyl)triethoxysilane may be used alone or in combination of two or more.

The silane coupling agent is contained in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the acrylic copolymer.

In addition, the photosensitive resin composition according to an embodiment of the present invention may further include a surfactant. Such a surfactant improves the coatability and developability of the photosensitive resin composition. Examples of such surfactants include silicone-based surfactants and fluorine-based surfactants. The surfactant is contained in an amount of 0.0001 to 2 parts by weight based on 100 parts by weight of solid content in the photosensitive resin composition.

Hereinafter, a pattern forming method using a photosensitive resin composition according to an embodiment of the present invention will be described. The photosensitive resin composition according to an embodiment of the present invention includes the steps of coating the photosensitive resin composition on a substrate, and heating the photosensitive resin composition to a temperature of 75° C. to 85° C. The method includes exposing and developing the photosensitive resin composition, and secondarily heating the developed photosensitive resin composition to a temperature of 80° C. to 90° C. The photosensitive resin composition used at this time is the same as the photosensitive resin composition described above. Duplicate explanations regarding the same components will be omitted.

1 to 4 are process flowcharts showing a pattern forming method according to an embodiment of the present invention.

Referring to FIG. 1, first, a photosensitive resin composition 400 is coated on a substrate 110 to form a coating layer of the photosensitive resin composition 400. As shown in FIG. At this time, coating is performed by a spray method, a roll coater method, a spin coating method, or the like.

At this time, the photosensitive resin composition contains 0.1 to 20 parts by weight of a radical photoinitiator, 0.1 to 10 parts by weight of an ionic photoinitiator, and a polyfunctional acrylate oligomer based on 100 parts by weight of the acrylic copolymer. 1 to 50 parts by weight, 1 to 50 parts by weight of a polyfunctional monomer having an ethylenically unsaturated bond, and a solvent. Since such a photosensitive resin composition simultaneously contains a radical photoinitiator and an ionic photoinitiator, it can be cured at a low temperature of 90°C or lower, and even when cured at a low temperature of 90°C or lower, it has excellent adhesive strength. and chemical resistance. Such a photosensitive resin composition is a negative photosensitive resin composition in which the exposed portion is cured and remains.

Next, referring to FIG. 2, the coated photosensitive resin composition 400 is first heated to a temperature of 75° C. to 85° C. This is a pre-baking process, which removes gas contained within the coated photosensitive resin composition 400. The primary heating is performed for about 1 minute to 5 minutes. At this time, since the photosensitive resin composition of the present invention uses a solvent with a low boiling point of less than 150°C, gases contained in the solvent can be removed better.

Next, referring to FIG. 3, the coated photosensitive resin composition is exposed and developed to form a photosensitive resin composition layer 410. The photosensitive resin composition according to an embodiment of the present invention is a negative photosensitive resin composition, in which the portion corresponding to the opening of the mask 700, that is, the exposed portion remains cured, and the unexposed portion remains. is removed. At this time, exposure uses visible light, ultraviolet rays, far ultraviolet rays, electron beams, X-rays, etc. For development, a developer is used to remove the areas that will not be exposed to light.

It is preferable to use an alkaline aqueous solution as the developer, specifically inorganic alkalis such as sodium hydroxide, potassium hydroxide, and sodium carbonate, primary amines such as n-propylamine, diethylamine, and n-propyl. Secondary amines such as amines, tertiary amines such as trimethylamine, methyldiethylamine, dimethylethylamine, triethylamine, alcohol amines such as dimethylethanolamine, methyldiethanolamine, triethanolamine, or tetramethylammonium hydroxide, tetraethylammonium hydroxy Use an aqueous solution of a quaternary ammonium salt such as At this time, the developer is used by dissolving an alkaline compound at a concentration of 0.1 to 10% by weight, and a water-soluble organic solvent such as methanol, ethanol, etc. and a surfactant may be added in appropriate amounts.

Next, referring to FIG. 4, the photosensitive resin composition layer 410 is secondarily heated to a temperature of about 80° C. to 90° C. The secondary heating is a step of curing the photosensitive resin composition layer 410. Such secondary heating is performed for about 30 minutes to 240 minutes. Since the photosensitive resin composition 400 according to an embodiment of the present invention is cured even at a temperature of 90° C. or lower, even when a light emitting layer or the like is located below the photosensitive resin composition, the insulating layer can be coated without damaging the light emitting layer. etc. can be manufactured.

In other words, the photosensitive resin composition of the present invention and the pattern forming method using the same can be applied to passivation insulating films, gate insulating films, and It can be used as a planarization film, column spacer, overcoat, or color resist. At this time, since the photosensitive resin composition is cured in a low-temperature process, it can be manufactured in a single process on top of a structure including a light emitting layer, thereby simplifying the process.

Furthermore, the structure of the manufactured display device can be simplified. As an example, a display device having a structure in which a touch panel is built in an organic light emitting element can be manufactured by the pattern forming method using the photosensitive resin composition according to this example. That is, touch sensing electrodes can be formed directly on the thin film sealing layer on the organic light emitting device, and the photosensitive resin composition according to this embodiment can be used as an insulating layer between the touch sensing electrodes. In the case of this structure, if the temperature exceeds 100° C. during the process of manufacturing the insulating film, the light emitting layer of the organic light emitting device will be damaged, which is not preferable. However, in the photosensitive resin composition and the pattern forming method using the same according to the present example, since the photosensitive resin composition is cured at a temperature of 90° C. or lower, an insulating film or the like can be manufactured without damaging the lower light emitting layer.

Hereinafter, effects of a photosensitive resin composition according to an embodiment of the present invention and a pattern forming method using the same will be explained through specific experimental examples.
Synthesis Example 1: (Production of acrylic copolymer)
A mixed solution of 400 parts by weight of tetrahydrofuran, 30 parts by weight of methacrylic acid, 30 parts by weight of styrene, and 40 parts by weight of glycidyl methacrylate was put into a flask equipped with a cooler and a stirrer. After thoroughly mixing the liquid composition at 600 rpm in a mixing container, 15 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) was added. The polymerization mixture solution was slowly raised to 55°C, maintained at this temperature for 24 hours, then cooled to room temperature, and 500 ppm of hydrobenzophenone was added as a polymerization inhibitor to obtain a polymer solution with a solid content concentration of 30% by weight. Ta.

In order to remove unreacted monomers from the polymer solution, 100 parts by weight of the polymer solution was precipitated with respect to 1000 parts by weight of n-hexane. After precipitation, the solvent (poor solvent) in which unreacted substances were dissolved was removed by a filtering process using a mesh. After that, in order to remove the solvent containing unreacted monomers that remains after the filtering process, the solvent containing unreacted monomers is completely removed by vacuum drying at 30°C or less, and the acrylic A copolymer was produced.

The weight average molecular weight of the acrylic copolymer was 6,000. At this time, the weight average molecular weight is a polystyrene equivalent average molecular weight measured using GPC.

Example 1: Preparation of negative photosensitive resin composition 100 parts by weight of the acrylic copolymer solution prepared in Synthesis Example 1, 2-(O-benzoyloxime)-1-[4-(phenylthio) as a radical photoinitiator ) 10 parts by weight of phenyl]-1,2-octanedione, 10 parts by weight of phenyl(4-methoxyphenyl)iodonium phosphorus hexafluoride as an ionic photoinitiator, 10 parts by weight of 10-functional urethane acrylate oligomer, ethylenically unsaturated bond. 20 parts by weight of dipentaerythritol hexaacrylate as a polyfunctional monomer, 3 parts by weight of hexamethylolmelamine hexamethyl ether as a melamine crosslinking agent, and 2 parts by weight of (3-glycidoxypropyl)methyldiethoxysilane as a silane coupling agent. were mixed. Propylene glycol monoethyl acetate was added and dissolved in the mixture to have a solid concentration of 20% by weight, and then filtered through a 0.2 μm Millipore filter to prepare a negative photosensitive resin composition coating solution.

Example 2: Production of negative photosensitive resin composition A photosensitive resin composition coating solution was produced in the same manner as in Example 1, except that ethylene glycol methyl ether acetate was used as the solvent.

Example 3: Production of negative photosensitive resin composition In the same manner as in Example 1 except that N,N-dimethyl-N-benzyltrifluoromethanesulfonic acid was used as the ionic photoinitiator in Example 1. A photosensitive resin composition coating solution was produced.

Example 4: Production of negative photosensitive resin composition The same procedure as in Example 1 was carried out except that 4-methylphenyl(4-(2-methylpropylphenyl))iodonium phosphorus hexafluoride was used as the ionic photoinitiator. A photosensitive resin composition coating solution was prepared in the same manner as in Example 1.

Example 5: Production of negative photosensitive resin composition Photosensitized in the same manner as in Example 1 except that phenyl(4-methoxyphenyl)iodonium arsenic hexafluoride was used as the ionic photoinitiator in Example 1. A resin composition coating solution was prepared.

Comparative Example 1: Production of negative photosensitive resin composition A photosensitive resin composition coating solution was produced in the same manner as in Example 1, except that 0.05 parts by weight of the ionic photoinitiator in Example 1 was used. did.

Comparative Example 2: Production of negative photosensitive resin composition A photosensitive resin composition coating solution was produced in the same manner as in Example 1, except that 25 parts by weight of the ionic photoinitiator in Example 1 was used.

Comparative Example 3: Production of negative photosensitive resin composition A photosensitive resin composition coating solution was produced in the same manner as in Example 1, except that the ionic photoinitiator in Example 1 was completely removed.

Comparative Example 4: Production of negative photosensitive resin composition 2-(O-acetyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione was used as the radical photoinitiator in Comparative Example 3. Except for this, a photosensitive resin composition coating solution was produced in the same manner as in Comparative Example 3.

Comparative Example 5: Production of negative photosensitive resin composition A photosensitive resin composition coating solution was produced in the same manner as in Example 1, except that ethyl lactate was used as the solvent in Example 1.

Comparative Example 6: Production of negative photosensitive resin composition A photosensitive resin composition coating solution was produced in the same manner as in Example 1, except that propylene glycol monomethyl propionate was used as the solvent in Example 1. .

The physical properties of the negative photosensitive resin composition coating solutions prepared in Examples 1 to 5 and Comparative Examples 1 to 6 were evaluated by the methods described in Experimental Examples 1 to 5 below, and the results are summarized in Table 1 below. It was shown to.

Experimental Example 1: Measurement of sensitivity and residual film rate Negative photosensitive compositions produced in Examples 1 to 5 and Comparative Examples 1 to 6 were coated on a glass substrate on which SiN _x was vapor-deposited using a spin coater. After applying the solution, it was prebaked on a hot plate at 80° C. for 2 minutes to form a 2.0 μm film. Using a predetermined pattern mask, the obtained film was exposed to ultraviolet rays with an intensity of 10 mW/cm ² at 365 nm for 1 to 5 seconds at 0.2 second intervals using a broadband exposure device. Irradiated. Thereafter, the film was developed with an aqueous solution of 2.38% by weight of tetramethylammonium hydroxide at 23° C. for 60 seconds, and then washed with ultrapure water for 60 seconds.

For final curing, a patterned film was obtained by heating in an oven at 85° C. for 60 minutes. Sensitivity was measured using a SEM based on the exposure amount at which the residual film rate was saturated based on a 20 μm line and space CD standard.

Experimental Example 2: Remaining film rate When measuring the sensitivity in Experimental Example 1, the residual film rate at which the sensitivity reached saturation was confirmed. At this time, if the remaining film rate was 80% or more, it was expressed as ○, if it was 80% to 75%, it was expressed as △, and if it was 75% or less, it was expressed as X.

Experimental Example 3: Residue Residue (Scum) was inspected using the contact hole of the pattern film formed during the sensitivity measurement in Experimental Example 1 as a reference. At this time, the case where no residue was observed was expressed as ○, and the case where a residue was observed was expressed as X.

Experimental Example 4: Adhesion Strength The case where peel-off of the patterned film formed during the sensitivity measurement in Experimental Example 1 did not occur was represented by ○, and the case where peel-off occurred was represented by X.

Experimental Example 5: Chemical Resistance The pattern film formed during the sensitivity measurement in Experimental Example 1 was placed in a stripper and left to stand, and then the change in thickness was measured. A case where the change in thickness at this time was 0.5 μm or less was represented by ○, a case from 0.5 μm to 1.0 μm was represented by Δ, and a case where the change was 1.0 μm or more was represented by X.

As can be confirmed from Table 1, Examples 1 to 5 containing an ionic photoinitiator and a low boiling point solvent according to one embodiment of the present invention have a high sensitivity, a residual film rate, a residue, an adhesive strength, and a It was confirmed that it has excellent chemical resistance.

Furthermore, when comparing Comparative Examples 1 and 2, in which the ionic photoinitiator content range is between 0.1 and 10 parts by weight, with Example 1, it is found that the ionic photoinitiator content range is between 0.1 and 10 parts by weight. It was confirmed that uniform performance in terms of residual film rate, residue, and adhesive strength can be achieved only when the content is in the range of 0.1 to 10 parts by weight. In other words, Comparative Example 1, in which the ionic photoinitiator content was 0.05 parts by weight, had a poor residual film rate and adhesive strength, and Comparative Example 2, in which the ionic photoinitiator content was 25 parts by weight, had a poor residual film rate and adhesive strength. was defective.

In other words, the photosensitive resin composition according to an embodiment of the present invention, which simultaneously contains a radical photoinitiator and an ionic photoinitiator, has excellent sensitivity, film retention rate, and residue, and is particularly suitable for low-temperature processing at 90°C or lower. It was confirmed that it has excellent adhesive strength and chemical resistance, and is suitable for use in flexible displays.

Although the embodiments of the present invention have been described in detail above, the scope of rights of the present invention is not limited thereto. Various modifications and improvements are also within the scope of the invention.

110: Substrate 400: Photosensitive resin composition 410: Photosensitive resin composition layer 700: Mask

Claims (6)

For 100 parts by weight of acrylic copolymer,
0.1 to 20 parts by weight of a radical photoinitiator,
0.1 to 10 parts by weight of an ionic photoinitiator,
1 to 50 parts by weight of polyfunctional acrylate oligomer,
Contains 1 to 50 parts by weight of a polyfunctional monomer having an ethylenically unsaturated bond and a solvent,
The acrylic copolymer is a copolymer consisting of an unsaturated carboxy compound and an olefin compound having a glycidyl group,
The radical photoinitiator is 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione, or 2-(O-acetyloxime)-1-[4-( phenylthio)phenyl]-1,2-octanedione,
The ionic photoinitiator is phenyl(4-methoxyphenyl)iodonium phosphorus hexafluoride, N,N-dimethyl-N-benzyltrifluoromethanesulfonic acid, 4-methylphenyl(4-(2-methylpropylphenyl))iodonium one or more selected from the group consisting of phosphorus hexafluoride, phenyl (4-methoxyphenyl) iodonium, arsenic hexafluoride,
The polyfunctional acrylate oligomer includes aliphatic urethane acrylate oligomer, aromatic urethane acrylate oligomer, epoxy acrylate oligomer, epoxy methacrylate oligomer, polyester acrylate oligomer, silicone acrylate oligomer, melamine acrylate oligomer, and tendritic acrylate oligomer alone or in combination. It is a mixture of more than one species,
The olefin compounds having a glycidyl group include glycidyl acrylate, glycidyl methacrylate, α-ethyl glycidyl acrylate, α-n-propyl glycidyl acrylate, α-n-butyl glycidyl acrylate, β-methylglycidyl acrylate, β-methylglycidyl methacrylate, β-ethylglycidyl acrylate, β-ethylglycidyl methacrylate, 3,4-epoxybutyl acrylate, 3,4-epoxybutyl methacrylate, 6,7 acrylate - Single or a mixture of two or more selected from the group consisting of epoxyheptyl, 6,7-epoxyheptyl methacrylate, α-ethyl acrylate-6,7-epoxyheptyl, and 3,4-epoxycyclohexyl methacrylate. can be,
A photosensitive resin composition, wherein the solvent has a boiling point of less than 150°C. The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition is cured at a temperature of 90°C or lower. The photosensitive resin composition according to claim 1, wherein the content ratio of the radical photoinitiator to the ionic photoinitiator is 2:1 to 1:2. The photosensitive resin composition according to claim 1, wherein the solid content of the photosensitive resin composition is 10% by weight to 50% by weight. The melamine crosslinking agent further includes a group including monomethylol urea, dimethylol urea, hexamethylol melamine, monomethyl urea methyl ether, dimethyl urea methyl ether, hexamethylol melamine hexamethyl ether, and hexamethylol melamine hexabutyl ether. The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition is one or more selected from the following. The silane coupling agent further includes (3-glycidoxypropyl)trimethoxysilane, (3-glycidoxypropyl)triethoxysilane, (3-glycidoxypropyl)methyldimethoxysilane. , (3-glycidoxypropyl)methyldiethoxysilane, (3-glycidoxypropyl)dimethylethoxysilane, 3,4-epoxybutyltrimethoxysilane, 3,4-epoxybutyltriethoxysilane, 2-(3 ,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, 3-triethoxysilane-N-(1,3 dimethyl-butylidene)propylamine, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, N-2(aminoethyl)3-aminopropylmethyldimethoxy The photosensitivity according to claim 1, characterized in that the photosensitive material is one or more selected from the group consisting of silane, N-phenyl-3-aminopropyltrimethoxysilane, and (3-isocyanatepropyl)triethoxysilane. Resin composition.

Images