TWI466349B - Photosensitive resin compound for organic thin film transistor - Google Patents

Description

Photosensitive resin composition for organic thin film transistor Technical field

The present invention relates to a photosensitive resin composition for an organic thin film transistor, and more particularly to a display for use in, for example, an organic thin film transistor or a flexible display using the organic thin film transistor and an OLED requiring a low temperature hardening program. In the case of the interlayer insulating film and the protective film, the photosensitive resin composition for an organic thin film transistor which can ensure heat resistance and chemical stability can be minimized by minimizing the amount of residual solvent during the heat treatment process.

Background technique

Recently, as the size of the display has increased and the selling price has continued to decrease, efforts have been continuously made to reduce costs, and the development of components using organic substances has been actively carried out.

Recently, the development of Organic Thin Film Transistor (OTFT) is advantageous because of the low price of the display, which is advantageous on the economical side compared with the components made of existing inorganic semiconductors, and at the same time, due to the advantages of imparting flexibility to the element, it is expected A core role in implementing flexible displays. However, when a conventional high temperature program of 200 ° C or higher is used in the manufacturing process of the flexible display element, the mobility of the organic semiconductor used in the channel portion is rapidly lowered, causing thermal deformation of the plastic substrate.

In order to solve such a problem, it is necessary to perform a low temperature program of 150 ° C or less. However, when a photosensitive resin composition for an interlayer insulating film used in an existing TFT-LCD is used, several problems occur. The main reason is that the existing insulating film It is designed according to the principle of hardening at a high temperature of 200 ° C or higher. When the curing temperature is lower than 150 ° C, the amount of residual solvent which cannot be volatilized in the film increases, and the residual solvent becomes a steric hindrance between the crosslinking groups. The main factor in the reduction of hardening degree. When the degree of hardening of the organic insulating film is lowered, the heat resistance is lowered not only in the heat treatment procedures of various stages such as vapor deposition of the conductive film (ITO), alignment film coating, and hardening, but also the solvent used in the subsequent preparation process is particularly performed. The problem of deterioration in chemical resistance such as swelling and lowering force caused by surface impregnation.

Invention

In order to solve such a technical problem, the object of the present invention is to provide an interlayer insulating film and a protective film which are used for, for example, an organic thin film transistor or a flexible display using the organic thin film transistor, and a display of an OLED requiring a low temperature curing process. A photosensitive resin composition for an organic thin film transistor which can ensure heat resistance and chemical stability by a high degree of curing, and a pattern forming method using the resin composition, can be minimized in the heat treatment process.

Moreover, the present invention also provides an organic thin film transistor containing a cured body of a photosensitive resin composition for an organic thin film transistor.

In order to achieve the above object, the present invention provides a photosensitive resin composition for an organic thin film transistor comprising: a) an acrylic copolymer having a glass transition temperature (Tg) or a melting temperature of 90 to 140 ° C, a novolac resin, and Poly Imine resin; b) 1,2-quinonediazide compound; and c) boiling point of 90 to 150 ° C, evaporation when n-BA (n-butyl acetate) is set to 1. A solvent with a speed of 0.3 to 1.0.

The photosensitive resin composition for an organic thin film transistor preferably comprises: a) a glass transition temperature (Tg) or an acrylic copolymer having a melting temperature of 90 to 140 ° C, a novolac resin, and 100 parts by weight of a polyimide resin. ; b) 5 to 50 parts by weight of the 1,2-diazide yttrium compound; and c) a boiling point of 90 to 150 ° C, and an evaporation rate of 0.3 to 1.0 when n-BA (n-butyl acetate) is set to 1. Further, the content of the solid portion of the aforementioned a) + b) is from 10 to 50% by weight.

Moreover, the present invention also provides a pattern forming method of an organic thin film transistor using the photosensitive resin composition for an organic thin film transistor.

Moreover, the present invention also provides an organic thin film transistor containing a cured body of the photosensitive resin composition for an organic thin film transistor.

The photosensitive resin composition for an organic thin film transistor of the present invention is excellent in curing degree under low-temperature curing conditions, and particularly has excellent heat resistance and chemical resistance due to high curing degree in a low temperature program of 90 to 150 °C. It is suitable not only as an interlayer insulating film for an organic thin film transistor (OTFT) requiring a low temperature process, but also as a flexible display using the organic thin film transistor and an interlayer insulating film for an OLED.

Best form for implementing the invention

Hereinafter, the present invention will be described in detail.

A photosensitive resin composition for an organic thin film transistor of the present invention, comprising There are: a) an acrylic copolymer having a glass transition temperature (Tg) or a melting temperature of 90 to 140 ° C, a novolak resin or a polyimide resin; b) a 1,2-diazide compound; and c) A solvent having a boiling point of 90 to 150 ° C and an evaporation rate of 0.3 to 1.0 when n-BA (n-butyl acetate) is set to 1.

In the photosensitive resin composition for an organic thin film transistor of the present invention, the a) glass copolymer having a glass transition temperature (Tg) or a melting temperature of 90 to 140 ° C, a novolak resin or a polyimide resin may be used. The ability to easily form a pattern when developing. The copolymer or the resin is selected from the group consisting of an acrylic copolymer having a glass transition temperature (Tg) or a melting temperature of 90 to 140 ° C, a novolac resin, and a polyimide resin, the acrylic copolymer, a novolak resin, and The polyimide resin has a glass transition temperature (Tg) or a melting temperature of 90 to 140 ° C and can be produced by a known production method. An acrylic copolymer is preferred.

As a specific example, an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride or a mixture thereof and a olefin-based compound may be subjected to a radical reaction in the presence of a solvent and a polymerization initiator as a monomer to obtain an acrylic copolymer. Things. It is preferred to further contain an unsaturated compound containing an epoxy group as a monomer.

As the unsaturated carboxylic acid used in the copolymerization of the acrylic copolymer, acrylic acid, methacrylic acid, methylene succinic acid, maleic acid, fumaric acid, ethyl acetate, or the like can be used. The anhydride form and the like.

Further, the olefin-based unsaturated compounds used in the copolymerization in the present invention are: methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, butyl methacrylate, and methacrylic acid. Butyl ester, cyclohexyl methacrylate, dicyclopentanyl methacrylate Methacrylate), cyclohexyl acrylate, isobornyl acrylate, isobornyl acrylate, phenyl methacrylate, phenyl acrylate, benzyl acrylate, benzyl methacrylate, Styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, etc. may be used alone or in combination of two or more.

Further, the epoxy group-containing unsaturated compound to be used in the copolymerization of the present invention may be: glycidyl acrylate, glycidyl methacrylate, methacrylic acid-β-methyl epoxide Ester, -6,7-epoxyheptyl methacrylate, o-vinylbenzyloxypropyl ether, m-vinylbenzyloxypropyl ether, p-vinylbenzyl epoxy For example, propyl ether or the like may be used alone or in combination of two or more.

In the production of the acrylic copolymer, the unsaturated carboxylic acid or its anhydride is 5 to 90% by weight, preferably 5 to 40% by weight, and preferably 10 to 30% by weight based on the total of the total monomers. %. When it is within the above range, the solubility with respect to the alkaline developing solution can be appropriately maintained.

Further, the olefin-based unsaturated compound is preferably 10 to 95% by weight, and preferably 20 to 50% by weight based on the total amount of the total amount. When the amount of the olefin-based unsaturated compound used is within the above range, the storage stability can be improved and the solubility in the developing solution can be appropriately maintained.

Further, the epoxy group-containing unsaturated compound is preferably used in an amount of from 0 to 70% by weight, preferably from 0 to 60% by weight, based on the total amount of the total amount. When the amount of the above-mentioned epoxy group-containing unsaturated compound is more than 70% by weight, the storage stability of the copolymer is lowered.

A radical polymerization initiator can be used as the acrylic copolymer copolymer Specific examples of the polymerization initiator used in the material include 2,2'-azobisisobutyronitrile and 2,2'-azobis(2,4-dimethylvaleronitrile). 2,2'-azobis(4-methoxy 2,4-dimethylvaleronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), dimethyl 2,2' - azobisisobutyrate or the like; for the solvent, for example, propylene glycol monoethyl ether acetate, ethyl ethoxypropionate, butylacetate, ethylene glycol monomethyl ether acetate, Propylene glycol monomethyl ether, propylene glycol methyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, cyclohexanone, ethyl 3-methoxypropionate, or 3-B As the methyl oxypropionate or the like, propylene glycol monoethyl ether, ethyl ethoxypropionate or butylacetate can be specifically used.

The acrylic copolymer or resin used in the present invention preferably has a weight average molecular weight (Mw) of 5,000 to 30,000 in terms of polystyrene, and preferably 5,000 to 20,000. When the film having a Mw of less than 5,000 is used, there is a problem that the developing property, the residual film ratio, and the like are lowered, or the pattern shape, heat resistance, and the like are deteriorated. When the film is more than 30,000, the sensitivity is lowered or the pattern shape is deteriorated.

The glass transition temperature (Tg) or melting temperature (softening temperature (softening temperature)) of the aforementioned a) copolymer or resin of the present invention is preferably from 90 to 140 ° C, preferably from 90 to 120 ° C. When the temperature is less than 90 ° C, the pattern characteristics, the residual film ratio, and the like are lowered, particularly the heat resistance is deteriorated, and when it is more than 140 ° C, the degree of hardening is poor, the chemical resistance, and the adhesion to the lower film are lowered. problem.

The b) 1,2-diazide yttrium compound used in the present invention is used as a photosensitive compound. As the above-mentioned 1,2-diazide yttrium compound, 1,2-diazide-4-sulfonate or 1,2-diazide-5-sulfonate can be used. Or 1,2-diazide-6-sulfonate or the like.

Such a bismuth diazide compound can be produced by reacting a diazonaphthoquinone sulfonate halide with a phenol compound in the presence of a weak base.

As the phenol compound, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,2'-tetrahydroxybenzophenone, 4,4'-tetrahydroxyl can be used. Benzophenone, 2,3,4,3'-tetrahydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,3,4,2'-tetrahydroxy 4' -methylbenzophenone, 2,3,4,4'-tetrahydroxy 3'-methoxybenzophenone, 2,3,4,2'-pentahydroxybenzophenone, 2,3,4 ,6'-pentahydroxybenzophenone, 2,4,6,3'-hexahydroxybenzophenone, 2,4,6,4'-hexahydroxybenzophenone, 2,4,6,5 -hexahydroxybenzophenone, 3,4,5,3'-hexahydroxybenzophenone, 3,4,5,4'-hexahydroxybenzophenone, 3,4,5,5'-hexa Hydroxybenzophenone, bis(2,4-dihydroxyphenyl)methane, bis(p-hydroxyphenyl)methane, tris(p-hydroxyphenyl)methane, 1,1,1-tris(p-hydroxyl Phenyl)ethane, bis(2,3,4-trihydroxyphenyl)methane, 2,2-bis(2,3,4-trihydroxyphenyl)propane, 1,1,3-tri(2, 5-Dimethyl 4-hydroxyphenyl)-3-phenylpropane, 4,4'-[1-[4-[1-[4-hydroxyphenyl]-1-methylethyl]phenyl] Ethylene] bisphenol, or double (2, 5-dimethyl 4-hydroxyphenyl)-2-hydroxyphenylmethane or the like, and the above compounds may be used singly or in combination of two or more.

When the bismuth subnitride compound is synthesized from such a phenol compound and a naphthoquinone sulfonate sulfonate, the degree of esterification is preferably from 50 to 90%. When the degree of esterification is within the above range, the residual film ratio becomes better, and the storage stability is improved.

The above-mentioned 1,2-diazide ruthenium compound is preferably contained in an amount of 5 to 50 parts by weight, preferably 10 to 40 parts by weight, based on 100 parts by weight of the above a) copolymer or resin. When the content is less than 5 parts by weight, the difference in solubility between the exposed portion and the non-exposed portion becomes small and it is difficult to form a pattern; when it is more than 50 parts by weight, When light is irradiated for a short period of time, a large amount of unreacted 1,2-diazide ruthenium compound remains, and the solubility in the aqueous alkali solution of the developing solution becomes too low, and there is a problem that it is difficult to develop.

The above c) solvent used in the photosensitive resin composition for an organic thin film transistor of the present invention has a boiling point of 90 to 150 ° C, and an evaporation rate of 0.3 to 1.0 when n-BA (n-butyl acetate) is set to 1. Low boiling point and high volatility solvent. The foregoing evaporation rate is expressed as n-BA (n-butyl acetate) when measured according to the Shell Thin-Film Evaporometer according to the evaporation rate standard test method ASTM D3539-87 (1996) of the volatile liquid. It is set to 1, and relatively shows the value of the measured solvent evaporation amount.

The above solvent preferably has a boiling point of 110 to 140 °C. When it is in the above range, the hardness is excellent even under low-temperature curing conditions, and the chemical resistance and heat resistance are excellent, and the reliability of the organic thin film transistor can be improved.

Specifically, the solvent may be used singly or in combination of two or more kinds thereof, for example, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, or propylene glycol alkyl ether acetate such as propylene glycol propyl ether acetate; propylene glycol; a propylene glycol monoalkyl ether such as methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether or propylene glycol butyl ether; n-butyl acetate. Propylene glycol monoethyl acetate, propylene glycol monomethyl ether, n-butyl acetate, and the like are preferably used.

The solvent is preferably contained in an amount of 10 to 50% by weight based on the solid content (a) + b) of the photosensitive resin composition for the entire organic thin film transistor, and preferably 15 to 40% by weight. contain. When the solid content of the entire composition is less than 10% by weight, there is a problem that the coating thickness becomes thin and the coating flatness is lowered; when it is more than 50% by weight, the coating thickness is thick. The degree becomes thick, and the problem of coating equipment is excessively weak at the time of coating.

Further, the photosensitive resin composition for an organic thin film transistor of the present invention may optionally contain an additive having a compatibility such as a photosensitizer, a surfactant, a thermal polymerization inhibitor, or an antifoaming agent, and the content may be 0.001 to 10% by weight, respectively.

The photosensitive resin composition for an organic thin film transistor of the present invention comprising the above-mentioned components is preferably used after being filtered with a Millipore filter of 0.1 to 0.2 μm or the like.

Moreover, the present invention provides a pattern forming method of an organic thin film transistor using the photosensitive resin composition for an organic thin film transistor, and an organic thin film transistor including a cured body of a photosensitive resin composition for an organic thin film transistor, The pattern forming method of the organic thin film transistor is characterized in that the organic thin film transistor photosensitive resin composition is used as an organic insulating film or a protective film material to form a pattern for forming an organic thin film transistor, and the organic method is used. A photosensitive resin composition for a film transistor.

The photosensitive resin composition for an organic thin film transistor of the present invention can be used in a method of generally forming a pattern of a display. As a specific example, the photosensitive resin composition for an organic thin film transistor can be applied onto the surface of an organic film substrate by a spray method, a roll coating method, a spin coating method, or the like, and the solvent can be removed by prebaking to form a coating film. In this case, it is preferred that the pre-baking is carried out at a temperature of 80 to 120 ° C for 1 to 15 minutes.

Thereafter, visible light rays, ultraviolet rays, far ultraviolet rays, electron beams, X-rays, and the like are irradiated onto the formed coating film by a pattern prepared in advance, and unnecessary portions are removed by development of the developing liquid, thereby forming a predetermined picture of. At this time, the hardening temperature is preferably 80 to 150 °C.

The above-mentioned developing solution is preferably an aqueous alkali solution, and specifically, an inorganic base such as sodium hydroxide, potassium hydroxide or sodium carbonate; a primary amine such as ethylamine or n-propylamine; diethylamine or a positive amine; a secondary amine such as propylamine; a tertiary amine such as trimethylamine, methyldiethylamine, dimethylethyl cavity or triethylamine; dimethylethanolamine, methyldiethanolamine, triethanolamine An alcohol amine or an aqueous solution of a quaternary ammonium salt such as tetramethylammonium hydroxide or tetraethylammonium hydroxide. In this case, the developing solution is used by dissolving the basic compound in a concentration of 0.1 to 10% by weight, and a water-soluble organic solvent such as methanol or ethanol or a surfactant may be added in an appropriate amount.

Furthermore, after developing with such a developing solution, it is washed with ultrapure water for 30 to 90 seconds to remove unnecessary portions, and dried to form a pattern, and heat-treated at a temperature of 80 to 150 ° C by a heating device such as an oven. The pattern is 30 to 90 minutes, and the final pattern is available.

The preferred embodiments are described below to understand the present invention, but the following examples are merely illustrative of the present invention, and the scope of the present invention is not limited by the following examples.

[Examples] Example 1

( Production of Acrylic Copolymer ) 10 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) and 600 parts by weight of tetrahydroxyfuran were added to a conical flask having a condenser and a stirrer. 30 parts by weight of methacrylic acid, 30 parts by weight of glycidyl methacrylate, 20 parts by weight of styrene, and 20 parts by weight of isodecyl methacrylate were subjected to nitrogen substitution, followed by stirring slowly. The reaction solution was heated to 60 ° C, and a polymer solution containing an acrylic copolymer was produced while maintaining the temperature for 26 hours.

In order to remove unreacted monomers of the polymer solution, 1,000 parts by weight of the aforementioned polymer solution was precipitated in 10,000 parts by weight of n-hexane with respect to a poor solvent (Poor Solvent). After the precipitation, the poor solvent in which the unreacted material was dissolved was removed by a filtration program using a mesh. Thereafter, in order to remove the solvent containing the unreacted monomer remaining after the filtration process, it was vacuum-dried at 30 ° C or lower and completely removed to produce an acrylic copolymer. The glass transition temperature of the acrylic copolymer produced as described above was 97 °C.

( Production of photosensitive resin composition for organic thin film transistor ) 100 parts by weight of the above- prepared acrylic copolymer was mixed with 4,4'-[1-[4-[1-[4-hydroxyphenyl]-1- 20 parts by weight of methyl ethyl]phenyl]ethylidene]bisphenol 1,2-diazide naphthoquinone-5-sulfonate, and dissolved in propylene glycol monoethyl acetate to make the aforementioned mixture The content of the solid portion was 30% by weight, and it was filtered through a 0.2 μm Millipore filter to prepare a photosensitive resin composition for an organic thin film transistor.

Example 2

When the acrylic copolymer of the above Example 1 was produced, 30 parts by weight of methacrylic acid, 60 parts by weight of isodecyl methacrylate, and 10 parts by weight of dicyclopentanyl methacrylate were used to produce a glass transition temperature of 117 ° C. In the acrylic copolymer, a photosensitive resin composition for an organic thin film transistor was produced in the same manner as in Example 1 except that propylene glycol monomethyl ether was used as the solvent of the photosensitive resin weight for the crystal.

Example 3

In the production of the acrylic copolymer of the above Example 1, 25 parts by weight of methacrylic acid, 25 parts by weight of glycidyl methacrylate, 15 parts by weight of isodecyl methacrylate, and dicyclopentanyl methacrylate 35 were used. The acrylic copolymer having a glass transition temperature of 130 ° C was produced in the same manner as in Example 1, except that n-butyl acetate was used as the solvent of the photosensitive resin weight for the crystal, to prepare an organic thin film transistor. A photosensitive resin composition is used.

Example 4

When the acrylic copolymer of the above Example 1 was produced, it was produced by using 30 parts by weight of methacrylic acid, 30 parts by weight of isodecyl methacrylate, 10 parts by weight of dicyclopentanyl methacrylate, and 30 parts by weight of styrene. A photosensitive resin composition for an organic thin film transistor was produced in the same manner as in Example 1 except that the glass-transfer temperature was 111 ° C.

Example 5

When the photosensitive resin composition for an organic thin film transistor of the above-mentioned Example 1 was produced, the same method as in Example 1 was carried out, except that a novolak-based copolymer having a glass transition temperature or a softening temperature (melting temperature) of 120 ° C was used. To produce a photosensitive resin composition for an organic thin film transistor.

Example 6

When the photosensitive resin composition for an organic thin film transistor of the above-mentioned Example 1 was produced, the same method as in Example 1 was carried out except that a polyimide resin having a glass transition temperature of 127 ° C was used to produce an organic thin film transistor. A photosensitive resin composition is used.

Comparative example 1

When the photosensitive resin composition for an organic thin film transistor of the above-mentioned Example 1 was produced, the same method as in Example 1 was carried out except that diethylene glycol methyl ether was used as a solvent to produce photosensitivity for an organic thin film transistor. Resin composition.

Comparative example 2

When the photosensitive resin composition for an organic thin film transistor of the above-mentioned Example 1 was produced, the same method as in Example 1 was carried out except that propylene glycol methyl ether propionate was used as a solvent to produce photosensitivity for an organic thin film transistor. Resin composition.

Comparative example 3

When manufacturing the acrylic copolymer of the above Example 1, 30 parts by weight of methacrylic acid, 10 parts by weight of glycidyl methacrylate, 40 parts by weight of dicyclopentan methacrylate, and 20 parts by weight of styrene were used. A photosensitive resin composition for an organic thin film transistor was produced in the same manner as in Example 1 except that an acrylic copolymer having a glass transition temperature of 152 ° C was produced.

Comparative example 4

When the photosensitive resin composition for an organic thin film transistor of the above-mentioned Example 1 was produced, the same method as in Example 1 was carried out, except that a novolak-based copolymer having a glass transition temperature or a softening temperature (melting temperature) of 82 ° C was used. To produce a photosensitive resin composition for an organic thin film transistor.

Comparative Example 5

Photosensitive resin for producing an organic thin film transistor of the foregoing Example 1 In the composition, a photosensitive resin composition for an organic thin film transistor was produced in the same manner as in Example 1 except that a polyimide resin having a glass transition temperature of 155 ° C was used.

The photosensitive resin composition for the organic thin film transistor manufactured in the above Examples 1 to 6 and Comparative Examples 1 to 5 was applied to a bare silicon wafer using a spin coater, and then preliminarily baked at 90 ° C on a hot plate. Bake for 2 minutes to form a film having a thickness of 3.6 μm. A predetermined pattern mask was used on the film formed in this manner, and ultraviolet rays having an intensity of 10 mW/cm ² at 365 nm were irradiated, and 10 μml: 1 CD was used as a reference exposure amount. Thereafter, the image was developed with a 0.38 wt% aqueous solution of tetramethylammonium hydroxide at 23 ° C for 2 minutes, and then washed with ultrapure water for 1 minute to obtain a pattern film, and after exposure to full exposure (500 mJ/cm ² ), A film was obtained by subjecting a 150 ° C convection oven to Curing for 60 minutes. After evaluating the following physical properties of the film, the results are shown in Table 1 below.

a) Chemical resistance: The film formed on the wafer was dipped at 70 ° C for 5 minutes, rinsed with ultrapure water, and cross-section was measured by FE-SEM to determine 10 μm CD before and after NMP treatment. Rate of change. When the rate of change is 0 to 20%, it is represented by ○, when it is 20 to 40%, it is represented by Δ, and when it is more than 40%, or when pattern peeling occurs, it is represented by ×.

b) TGA analysis: After peeling off the film formed on the wafer by a knife, a sample of 30 mg each was obtained. The weight loss (% by weight) of the obtained sample was measured by TGA (thermogravimetric analysis equipment) under isothermal conditions of 220 ° C for 60 minutes. At this time, when the weight loss generated is 0.5% by weight, it is represented by ○, and when it is 0.5 to 1.5% by weight, it is represented by Δ, and is more than 1.5% by weight. It is indicated by ×.

c) Thickness change rate: The film formed on the wafer was further cured by a convection oven at 150 ° C for 60 minutes, and then the cross section was measured by FE-SEM to determine the thickness change rate. When the rate of change is 0 to 3%, it is represented by ○, when it is 3 to 10%, it is represented by Δ, and when it is 10% or more, it is represented by ×.

As is apparent from the above Table 1, the photosensitivity of the organic thin film transistor obtained by using the acrylic copolymer resin, the novolak copolymer, and the polyimide resin and the specific solvent having a low boiling point in Examples 1 to 6 produced by the present invention The resin composition is excellent in the degree of hardening even under low-temperature curing conditions, and is excellent in heat resistance and chemical resistance to the heat treatment process and the specific solvent in the post-production process. In particular, in Comparative Example 4, there was a problem that the heat resistance of the novolak resin was lowered, and in Comparative Example 5, there was a problem that sufficient hardening did not occur under the hardening conditions imparted.

According to the above results, it has been confirmed that the present invention has excellent properties when it is used as an interlayer insulating film of an organic thin film transistor requiring a low temperature process and a flexible display and an OLED protective film using the organic thin film transistor.

Claims (9)

A photosensitive resin composition for an organic thin film transistor comprising: a) an acrylic copolymer having a glass transition temperature (Tg) or a melting temperature of 90 to 140 ° C, a novolac resin, and a polyimide resin; b) a 2-diazide hydride compound; and c) a solvent having a boiling point of from 90 to 150 ° C and an evaporation rate of from 0.3 to 1.0 when n-BA (n-butyl acetate) is set to 1. The photosensitive resin composition for an organic thin film transistor according to the first aspect of the invention includes: a) an acrylic copolymer having a glass transition temperature (Tg) or a melting temperature of 90 to 140 ° C, a novolac resin, and a polyfluorene 100 parts by weight of the imine resin; b) 5 to 50 parts by weight of the 1,2-diazide hydride compound; and c) a boiling point of 90 to 150 ° C, as measured by a shell film evaporation meter according to ASTM D3539-87, When n-BA (n-butyl acetate) is set to 1, the evaporation rate is 0.3 to 1.0, and the solid content of the aforementioned a) + b) is 10 to 50% by weight of the solvent. The photosensitive resin composition for an organic thin film transistor according to the first aspect of the invention, wherein the copolymer or resin of the above a) has a polystyrene-equivalent weight average molecular weight (Mw) of 5,000 to 30,000. The photosensitive resin composition for an organic thin film transistor according to the first aspect of the invention, wherein the solvent has a boiling point of 110 to 140 °C. The photosensitive resin composition for an organic thin film transistor according to the first aspect of the invention, wherein the solvent is selected from the group consisting of n-butyl acetate and propylene glycol. One or more groups of methyl ether ethyl ester and propylene glycol methyl ether. A method of forming a pattern of an organic thin film transistor, which is a photosensitive resin composition for an organic thin film transistor according to any one of claims 1 to 5. A pattern forming method of an organic thin film transistor according to claim 6, wherein the hardening temperature at the time of forming the pattern is 80 to 150 °C. An organic thin film transistor which is a cured body of a photosensitive resin composition for an organic thin film transistor according to any one of claims 1 to 5. The organic thin film transistor of claim 8, wherein the hardened body is an insulating film or a protective film of an organic thin film transistor.