KR20160113593A - Resin composition for forming microlens - Google Patents

Abstract

(식 중, X는 시클로헥실기 또는 페닐기를 나타내고, Y는 페닐기, 비페닐릴기 또는 나프틸기를 나타내고, R⁰은 각각 독립적으로 수소원자 또는 메틸기를 나타내고, R¹은 수소원자 또는 탄소원자수 1 내지 3의 알킬기를 나타내고, R²는 탄소원자수 1 내지 10의 직쇄상, 분지쇄상 또는 환상의 알킬기를 나타내고, R¹과 R²는 서로 결합하여 4 내지 7원환의 함산소환구조를 형성할 수도 있고, R³은 단결합 또는 탄소원자수 1 내지 5의 알킬렌기를 나타내고, 해당 알킬렌기는 그 중에 에테르결합을 가질 수도 있고, R⁴는 에폭시기, 또는 에폭시환을 갖는 탄소원자수 5 내지 12의 유기기를 나타낸다.)There is provided a resin having a structural unit represented by the following formula (1), (2), (3) and (4) and a resin for forming a microlens containing a solvent.

(Wherein X represents a cyclohexyl group or a phenyl group, Y represents a phenyl group, a biphenylyl group or a naphthyl group, each of R ⁰ independently represents a hydrogen atom or a methyl group, R ¹ represents a hydrogen atom, R ² represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, R ¹ and R ² may combine with each other to form a 4 to 7-membered heterocyclic hydrocarbon ring structure, R ³ represents a single bond or an alkylene group having 1 to 5 carbon atoms, the alkylene group may have an ether bond therein, and R ⁴ represents an organic group having 5 to 12 carbon atoms and having an epoxy group or an epoxy ring. )

Description

[0001] RESIN COMPOSITION FOR FORMING MICROLENS [0002]

The present invention relates to a resin composition for forming a microlens. More particularly, the present invention relates to a resin composition used for forming microlenses by an etch-back method.

2. Description of the Related Art In recent years, as the CCD / CMOS image sensor has progressed to a higher resolution, it has become necessary to improve the sensitivity of the sensor. For the mounted microlens, high transparency and high heat resistance are required.

One of the methods for manufacturing a microlens for a CCD / CMOS image sensor is an etch-back method (Patent Document 1 and Patent Document 2). That is, a resist pattern is formed on the resin layer for a microlens formed on the color filter layer, and the resist pattern is reflowed by heat treatment to form a lens pattern. Using the lens pattern formed by reflowing the resist pattern as an etching mask, the lower resin layer for microlenses is etched back, and the lens pattern shape is transferred to the resin layer for microlenses to manufacture a microlens.

In the etch-back method, when the lens pattern shape is faithfully transferred to the lower-layer micro-lens resin layer, the dry etching rate X of the resist film and the dry etching rate Y of the resin layer for the microlens are equal (for example, X: Y = 1: 0.8 to 1.2) (Patent Document 3 and Patent Document 4).

Japanese Patent Application Laid-Open No. H1-10666 Japanese Patent Application Laid-Open No. H6-112459 International Publication No. 2013/005619 International Publication No. 2013/035569

An object of the present invention is to provide a thermosetting resin composition excellent in transparency, heat resistance, solvent resistance, flatness and a dry etching rate equivalent to that of a resist film and excellent in storage stability . Another object of the present invention is to provide a microlens having excellent transparency, heat resistance and solvent resistance.

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above problems, and have completed the present invention.

That is, the present invention is a resin composition for forming a microlens containing a copolymer having a structural unit represented by the following formula (1), (2), (3) and (4) and a solvent.

[Chemical Formula 1]

(Wherein X represents a cyclohexyl group or a phenyl group, Y represents a phenyl group, a biphenylyl group or a naphthyl group, each R ⁰ independently represents a hydrogen atom or a methyl group, R ¹ represents a hydrogen atom, R ² represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, R ¹ and R ² may combine with each other to form a 4 to 7-membered heterocyclic hydrocarbon ring structure, R ³ represents a single bond or an alkylene group having 1 to 5 carbon atoms, the alkylene group may have an ether bond therein, and R ⁴ represents an organic group having 5 to 12 carbon atoms and having an epoxy group or an epoxy ring. )

The present invention is also a cured film obtained from the resin composition for forming a micro lens. Further, the present invention relates to a micro lens made of the resin composition for forming a micro lens and a manufacturing method thereof. The microlenses are manufactured by, for example, the above-described etch-back method. That is, a method of manufacturing a color filter substrate, which comprises: applying a resin composition for forming a microlens of the present invention onto a color filter layer and baking to form a resin layer; forming a resist pattern on the resin layer using a resist composition; Forming a lens pattern by reflowing, and etching the resin layer using the lens pattern as an etching mask. The reflow is performed by heating the resist pattern at a temperature not lower than the glass transition temperature (Tg) of the resist pattern, usually less than 200 ° C.

In the resin composition for forming a microlens of the present invention, since the copolymer contained in the composition is of the self-crosslinking type, it is not necessarily required to add a crosslinking agent, and it has thermosetting property and, in the structural unit represented by the formula (3) Since the carboxyl group is blocked, the storage stability is excellent. Furthermore, the film formed of the resin composition for forming a microlens of the present invention has excellent transparency, heat resistance, solvent resistance, glass transition temperature (Tg) of 200 DEG C or more and etching rate equivalent to that of a resist film.

As described above, in the film formed of the resin composition for forming a microlens of the present invention, when the heating process at a high temperature is performed in the forming process or the process of forming peripheral devices such as wiring, the microlenses are colored, The possibility that the shape is deformed can be remarkably reduced. When the resin layer is formed of the resin composition for forming a microlens of the present invention and the resist solution is coated on the resin layer and when the electrode / wiring formation process is performed after forming the microlenses, mixing with the resist, It is possible to remarkably reduce the problems such as deformation and peeling of the microlens by the lens. Therefore, the resin composition for forming a microlens of the present invention is suitable as a material for forming a microlens.

The present invention is a resin composition containing a copolymer and a solvent. Hereinafter, each component will be described in detail. In the resin composition of the present invention, the solid content excluding the solvent is usually 1% by mass to 50% by mass.

<Copolymer>

The copolymer contained in the resin composition of the present invention is a copolymer having a structural unit represented by the above-mentioned formulas (1), (2), (3) and (4)

Specific examples of the compound (monomer) forming the structural unit represented by the above formula (1) include N-cyclohexylmaleimide and N-phenylmaleimide. These compounds may be used alone or in combination of two or more.

Specific examples of the compound (monomer) forming the structural unit represented by the formula (2) include styrene,? -Methylstyrene, 2-vinylbiphenyl, 3-vinylbiphenyl, 4- Vinyl naphthalene and 2-vinylnaphthalene. These compounds may be used alone or in combination of two or more.

The structural unit represented by the formula (3) is, for example, a structural unit represented by the following formula (3-1) or (3-2).

(2)

(Wherein R ⁰ represents a hydrogen atom or a methyl group, R ² represents a linear, branched or cyclic alkyl group of 1 to 10 carbon atoms, and b represents 1 or 2.)

Specific examples of the compound (monomer) forming the structural unit represented by the formula (3) include 1-methoxyethyl (meth) acrylate, 1-ethoxyethyl (meth) (Meth) acrylate, 1-n-butoxyethyl (meth) acrylate, 1-n-butoxyethyl Monomers such as ethyl (meth) acrylate, 1-cyclohexyloxyethyl (meth) acrylate and tetrahydro-2H-pyran-2-yl (meth) acrylate. On the other hand, these monomers may be used alone or in combination of two or more.

The compound (monomer) forming the structural unit represented by the formula (3) can be produced by a method of polymerizing an acrylate or methacrylate having a protected carboxyl group obtained by reacting acrylic acid or methacrylic acid with an alkenyl ether compound, Or a method of reacting a polymer of methacrylic acid with an alkenyl ether compound.

The alkenyl ether compound used herein is a compound represented by the following formula (5).

(3)

(Wherein R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ² represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, R ¹ and R ² are bonded to each other And may form a 4 to 7 membered heterocyclic structure.

The reaction between a compound having a carboxyl group and an alkenyl ether compound can be carried out, for example, by stirring monoctyl phosphate, which is one of phosphoric acid esters, as a catalyst at 70 ° C.

Examples of the alkenyl ether compound represented by the above formula (5) include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, aliphatic vinyl ether compounds such as n-hexyl vinyl ether, cyclohexyl vinyl ether, 2-ethylhexyl vinyl ether, norbornyl vinyl ether, 1-adamantyl vinyl ether and 2-adamantyl vinyl ether, Cyclic vinyl ether compounds such as hydrofuran, 4-methyl-2,3-dihydrofuran and 2,3-dihydro-4H-pyran.

The structural unit represented by the formula (4) is, for example, a structural unit represented by the following formula (4-1), (4-2) or (4-3).

[Chemical Formula 4]

(Wherein R &lt; ⁰ &gt; each independently represents a hydrogen atom or a methyl group).

Specific examples of the compound (monomer) forming the structural unit represented by the formula (4) include glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, 3,4- And epoxycyclohexylmethyl (meth) acrylate. These monomers may be used alone or in combination of two or more.

In the copolymer having the structural unit represented by the formula (1), the formula (2), the formula (3) and the formula (4), the structural unit represented by the formula (1) , The content of the structural unit represented by the formula (1) is preferably from 5 mol% to 80 mol% with respect to 100 mol% of the sum of the structural unit represented by the formula (3) and the structural unit represented by the formula (4) , Preferably 10 mol% to 70 mol%, and the content of the structural unit represented by the formula (2) is 5 mol% to 80 mol%, preferably 10 mol% to 70 mol%, the structural unit represented by the formula (3) The content of the structural unit represented by the formula (4) is from 5 mol% to 40 mol%, preferably from 10 mol% to 30 mol%, and more preferably from 10 mol% to 30 mol%.

The weight average molecular weight of the copolymer is usually 1,000 to 100,000, preferably 3,000 to 50,000. On the other hand, the weight average molecular weight is a value obtained by gel permeation chromatography (GPC) using polystyrene as a standard sample.

The content of the copolymer in the resin composition of the present invention is usually 1% by mass to 99% by mass, and preferably 5% by mass to 95% by mass, based on the content in the solid content of the resin composition.

In the present invention, the method for obtaining the copolymer is not particularly limited, but it is generally preferred to use a compound which forms the structural unit represented by the above-mentioned formulas (1), (2), (3) (Monomer) in a solvent in the presence of a polymerization initiator, usually at a temperature of 50 ° C to 120 ° C. The copolymer thus obtained is usually in a solution state dissolved in a solvent and may be used in the resin composition of the present invention without being isolated in this state.

Further, the solution of the copolymer thus obtained is added to a poor solvent such as hexane, diethyl ether, methanol, water or the like to reprecipitate the copolymer, and the resulting precipitate is filtered and washed, The copolymer can be made into a powder by drying at room temperature under low pressure or by heating and drying. Through such operations, the polymerization initiator coexisting with the copolymer and the unreacted compound can be removed. In the present invention, the powder of the copolymer may be used as it is, or the powder may be used as a solution state by re-dissolving it in, for example, a solvent described later.

The method for preparing the resin composition of the present invention is not particularly limited. For example, a method of preparing a copolymer having a structural unit represented by the above formulas (1), (2), (3) and (4) To give a homogeneous solution. Further, in a suitable step of the preparation method, if necessary, other additives may be further added and mixed.

The solvent is not particularly limited as long as it dissolves the copolymer. Such solvents include, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, Propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether, propylene glycol monobutyl ether And examples of the solvent include acetone, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy- Methyl 3-methylbutanoate, 3- Methyl ethyl ketone, methyl methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, Lactones. These solvents may be used alone or in combination of two or more.

Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 2-heptanone, ethyl lactate, butyl lactate, propylene glycol monomethyl ether acetate, Cyclopentanone and cyclohexanone are preferred.

The resin composition of the present invention may contain a surfactant for the purpose of improving the coating property.

Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether and the like, polyoxyethylene octylphenyl Polyoxyethylene alkylaryl ethers such as ether, polyoxyethylene nonylphenyl ether and the like, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan Sorbitan fatty acid esters such as monooleate, sorbitan trioleate and sorbitan tristearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monostearate, Polyoxyethylene sorbitan trioleate such as polyoxyethylene sorbitan trioleate and polyoxyethylene sorbitan tristearate, (Registered trademark) EF301, EFTOP EF303, EFTOP EF352 (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), MEGAFAC (megafac) [registered trademark] (Manufactured by DIC CORPORATION), FLUORAD FC430, FLUORAD FC 431 (above, Sumitomo 3M (trade name, manufactured by DIC CORPORATION)), MEGAFAC R-30, MEGAFAC R- SURFLON SC101, SURFLON SC102, SURFLON SC103, SURFLON SC104, SURFLON SC105, SURFLON SC106 (manufactured by Asahi Glass Co., Ltd.), ASAHI GUARD (registered trademark) AG710, SURFLON (registered trademark) FTX-220D, FTX-228P, FTX-240D, FTX-230D, FTX-240D, FTX-212P, FTX-220P, FTX- , Fluorine surfactants such as FTERGENT series (manufactured by Neos Co., Ltd.), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). These surfactants may be used alone or in combination of two or more.

When the surfactant is used, the content of the surfactant in the resin composition of the present invention is 3% by mass or less, preferably 1% by mass or less, more preferably 1% by mass or less based on the content in the solid content of the resin composition Is 0.5 mass% or less.

The resin composition of the present invention may contain additives such as a cross-linking agent, a curing assistant, an ultraviolet absorber, a sensitizer, a plasticizer, an antioxidant, a light stabilizer, and an adhesion aid if necessary, .

Hereinafter, the micro lens manufacturing method of the present invention, which is a typical use example of the cured film obtained from the resin composition of the present invention, will be described. This method includes the following four steps.

First, a substrate (for example, a semiconductor substrate such as silicon covered with a silicon oxide film, a semiconductor substrate such as silicon covered with a silicon nitride film or a silicon oxynitride film, a semiconductor substrate such as silicon formed with a color filter, a silicon nitride substrate, , A glass substrate (including an alkali-free glass, a low alkali glass, and a crystallized glass), and a glass substrate on which an ITO film is formed) is coated with the resin composition of the present invention by a suitable coating method such as a spinner or a coater, Baking and curing by using a heating means of a microlens to form a resin layer for a microlens.

The bake conditions are suitably selected within a range of from 80 to 300 DEG C for the bake temperature and from 0.3 to 60 minutes for the bake time. The bake may be processed in two or more steps.

The film thickness of the film formed of the resin composition of the present invention is, for example, 0.001 to 100 탆, preferably 0.01 to 10 탆.

Thereafter, a resist solution is applied onto the resin layer for a microlens formed of the resin composition of the present invention, exposed through a predetermined mask, subjected to post exposure baking (PEB) if necessary, and subjected to alkali development, rinsing, Thereby forming a predetermined resist pattern. For exposure, g-line, i-line, KrF excimer laser, or ArF excimer laser can be used, for example.

Then, the resist pattern is reflowed to form a lens pattern by heat treatment. Then, using this lens pattern as an etching mask, the resin layer for the lower microlens is etched back, and the lens pattern shape is transferred to the resin layer for the microlens to manufacture the microlens.

Example

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[Measurement of the weight average molecular weight of the obtained copolymer]

Device: JASCO Corporation GPC system

Column: Shodex [registered trademark] KF-804L and KF-803L

Column oven: 40 ℃

Flow rate: 1 mL / min

Eluent: Tetrahydrofuran

[Synthesis of Copolymer]

&Lt; Synthesis Example 1 &

5.0 g of N-phenylmaleimide, 4.5 g of 2-vinylnaphthalene, 3.6 g of 1-n-butoxyethyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate (CYCLOMER [registered trademark] M100 ) And 0.84 g of 2,2'-azobisisobutyronitrile were dissolved in 41.2 g of cyclohexanone, and then this solution was added to a flask maintained at 70 ° C. in 11.8 g of cyclohexanone for 4 hours / RTI &gt; After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 30,000 (in terms of polystyrene).

&Lt; Synthesis Example 2 &

, 2.7 g of 1-n-butoxyethyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether (4HBAGE (manufactured by Nippon Kasei Chemical Company Limited)), 5.0 g of N-phenylmaleimide, And 0.83 g of 2,2'-azobisisobutyronitrile were dissolved in 40.5 g of cyclohexanone, and then this solution was added dropwise to a flask maintained at 70 DEG C with 11.6 g of cyclohexanone dropwise over 4 hours Respectively. After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 20,000 (in terms of polystyrene).

&Lt; Synthesis Example 3 &

N-phenylmaleimide, 5.3 g of 4-vinylbiphenyl, 1.8 g of 1-n-butoxyethyl methacrylate, 1.4 g of glycidyl methacrylate, and 2,2'-azobisisobutyronitrile Was dissolved in 41.7 g of cyclohexanone, and then 11.9 g of cyclohexanone was added dropwise to the flask maintained at 70 캜 over 4 hours. After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 22,000 (in terms of polystyrene).

&Lt; Synthesis Example 4 &

3.5 g of N-phenylmaleimide, 10.9 g of 4-vinylbiphenyl, 1.9 g of 1-n-butoxyethyl methacrylate, 1.5 g of glycidyl methacrylate, and 2,2'-azobisisobutyronitrile Was dissolved in 43.5 g of cyclohexanone, and then this solution was added dropwise to a flask maintained at 70 DEG C for 12 hours while cyclohexanone was added dropwise over 4 hours. After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 18,000 (in terms of polystyrene).

&Lt; Synthesis Example 5 &

3.5 g of N-cyclohexylmaleimide, 10.5 g of 4-vinylbiphenyl, 1.7 g of tetrahydro-2H-pyran-2-yl methacrylate, 1.4 g of glycidyl methacrylate, 0.86 g of isobutyronitrile was dissolved in 42.0 g of cyclohexanone, and then 12.0 g of cyclohexanone was added dropwise to the flask maintained at 70 캜 over 4 hours. After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 16,000 (in terms of polystyrene).

&Lt; Synthesis Example 6 &

3.5 g of N-cyclohexylmaleimide, 10.5 g of 4-vinylbiphenyl, 1.3 g of 2-hydroxyethylmethacrylate, 2.5 g of 2- (O- [1'-methylpropylideneamino] carboxyamino) ethyl methacrylate 2.4 g of Karenz TM MOI-BM (manufactured by Showa Denko KK) and 0.88 g of 2,2'-azobisisobutyronitrile were dissolved in 43.4 g of cyclohexanone, and then this solution was dissolved in cyclohexanone Was dropwise added to the flask maintained at 70 占 폚 over 4 hours. After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 19,000 (in terms of polystyrene).

&Lt; Synthesis Example 7 &

(O- [1'-methylpropylideneamino] carboxyamino) ethyl methacrylate (Karenz (registered trademark) (registered trademark) (Manufactured by Showa Denko KK), and 0.86 g of 2,2'-azobisisobutyronitrile were dissolved in 42.0 g of cyclohexanone, and then this solution was mixed with 12.0 g of cyclohexanone Was added dropwise to the flask kept at 70 캜 over 4 hours. After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 21,000 (in terms of polystyrene).

&Lt; Synthesis Example 8 &

, 2.4 g of styrene, 7.1 g of 2-vinylnaphthalene, 1.5 g of 2-hydroxyethyl methacrylate, 1.5 g of 2 - [(3,5-dimethylpyrazolyl) carboxyamino] ethyl methacrylate 2.9 g of Karenz TM registered trademark MOI-BP (manufactured by Showa Denko KK) and 0.90 g of 2,2'-azobisisobutyronitrile were dissolved in 43.9 g of cyclohexanone, and this solution was dissolved in cyclohexanone Was dropwise added to a flask maintained at 70 占 폚 over 4 hours. After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 15,000 (in terms of polystyrene).

&Lt; Synthesis Example 9 &

12.0 g of styrene, 1.9 g of 2-hydroxyethyl methacrylate, 1.5 g of 2- (O- [1'- methylpropylideneamino] carboxyamino) ethyl methacrylate (Karenz TM MOI-BM (produced by Showa Denko KK ) And 0.87 g of 2,2'-azobisisobutyronitrile were dissolved in 42.5 g of cyclohexanone, and then this solution was added dropwise to a flask maintained at 70 DEG C for 12 hours, / RTI &gt; After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 16,000 (in terms of polystyrene).

&Lt; Synthesis Example 10 &

14.0 g of 2-vinylnaphthalene, 2.1 g of 1-n-butoxyethyl methacrylate, 1.6 g of glycidyl methacrylate, and 1.3 g of 2,2'-azobisisobutyronitrile were mixed with 44.3 g of cyclohexanone After the solution was dissolved, 12.6 g of cyclohexanone was added dropwise to the flask maintained at 70 캜 over 4 hours. After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 7,000 (in terms of polystyrene).

&Lt; Synthesis Example 11 &

Vinylnaphthalene, 3.4 g of 2-hydroxyethyl methacrylate, 2.5 g of 2- (O- [1'-methylpropylideneamino] carboxyamino) ethyl methacrylate (Karenz TM MOI-BM Manufactured by Denko KK) and 0.88 g of 2,2'-azobisisobutyronitrile were dissolved in 43.3 g of cyclohexanone, and then this solution was added to a solution of 12.4 g of cyclohexanone in a flask maintained at 70 ° C. Was added dropwise over 4 hours. After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 20,000 (in terms of polystyrene).

&Lt; Synthesis Example 12 &

, 9.0 g of 4-vinylbiphenyl, 4.7 g of 1-n-butoxyethyl methacrylate, 3.6 g of glycidyl methacrylate and 0.86 g of 2,2'-azobisisobutyronitrile were mixed with 42.1 g of cyclohexanone , And then this solution was added dropwise in a flask maintained at 70 캜 for 12 hours in cyclohexanone over 4 hours. After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 14,000 (in terms of polystyrene).

&Lt; Synthesis Example 13 &

8.0 g of N-phenylmaleimide, 3.0 g of 2-hydroxyethyl methacrylate, 2 g of 2 - [(3,5-dimethylpyrazolyl) carbonylamino] ethyl methacrylate (Karenz TM MOI- Manufactured by Denko KK) and 0.84 g of 2,2'-azobisisobutyronitrile were dissolved in 41.2 g of cyclohexanone, and then this solution was added to a solution of 11.8 g of cyclohexanone in a flask maintained at 70 ° C. Was added dropwise over 4 hours. After completion of the dropwise addition, the reaction was continued for another 18 hours to obtain a copolymer solution (solid content concentration: 25 mass%). The weight average molecular weight Mw of the obtained copolymer was 19,000 (in terms of polystyrene).

[Preparation of resin composition for forming microlenses]

&Lt; Example 1 >

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 1 (including solid of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

&Lt; Example 2 >

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 2 (including solid of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

&Lt; Example 3 >

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 3 (including solid of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

<Example 4>

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 4 (including solid content of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

&Lt; Example 5 >

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 5 (containing 10.0 g of solid content). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

&Lt; Reference Example 1 &

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 6 (including solid of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

<Reference Example 2>

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 7 (including solid of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

<Reference Example 3>

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 8 (including solid of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

&Lt; Comparative Example 1 &

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 9 (including solid of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

&Lt; Comparative Example 2 &

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 10 (including solid of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

&Lt; Comparative Example 3 &

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 11 (including solid of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

&Lt; Comparative Example 4 &

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 12 (including solid of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

&Lt; Comparative Example 5 &

0.01 g of MEGAFAC [registered trademark] R-30 (manufactured by DIC CORPORATION) was dissolved as a surfactant in 40.0 g of the solution of the copolymer obtained in Synthesis Example 13 (including solid of 10.0 g). Thereafter, the mixture was filtered using a microfilter made of polyethylene having a pore diameter of 0.10 mu m to prepare a resin composition for forming a microlens.

[Solubility test]

The resin compositions for forming microlenses prepared in Examples 1 to 5, Reference Examples 1 to 3, and Comparative Examples 1 to 5 were each coated on a silicon wafer using a spin coater, And baking was performed at 100 캜 for 1 minute and then at 230 캜 for 10 minutes to form a film having a thickness of 2 탆. To these membranes, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl acetate, methyl 3-methoxypropionate, acetone, methyl isobutyl ketone, 2- % Aqueous solution of tetramethylammonium hydroxide (TMAH) at a temperature of 23 캜 for 5 minutes, respectively. The change in film thickness before and after immersion was measured, and when any of the above-mentioned immersion treatments was "x" when the film thickness was increased by 5% or more with respect to the film thickness before immersion, and when the change in film thickness was less than 5% Was evaluated as &quot;?&Quot;. The evaluation results are shown in Table 1.

[Measurement of transmittance]

The resin compositions for forming microlenses prepared in Examples 1 to 5, Reference Examples 1 to 3, and Comparative Examples 1 to 5 were each coated on a quartz substrate using a spin coater, And baking was performed at 100 캜 for 1 minute and then at 230 캜 for 10 minutes to form a film having a thickness of 2 탆. The transmittance of these films was measured by changing the wavelength by 2 nm in a wavelength range of 400 nm to 800 nm using an ultraviolet visible spectrophotometer UV-2550 (manufactured by Shimadzu Corporation). After heating the film at 260 ° C for 5 minutes, the transmittance was again measured by changing the wavelength in the range of 400 nm to 800 nm by 2 nm. Table 1 shows values of the lowest transmittance measured in the wavelength range of 400 nm to 800 nm before and after heating at 260 占 폚 for 5 minutes.

[Measurement of dry etching rate]

Etchers and etching gases used for measuring the dry etching rate are as follows.

Etcher: RIE-10NR (made by SAMCO Inc.)

Etching gas: CF ₄

The resin compositions for forming microlenses prepared in Examples 1 to 5, Reference Examples 1 to 3, and Comparative Examples 1 to 5 were each coated on a silicon wafer using a spin coater, And baking was performed at 100 캜 for 1 minute and then at 230 캜 for 10 minutes to form a film having a thickness of 2 탆. The dry etch rate of these films was measured using the etch and the etching gas. Likewise, a resist solution (THMR-iP1800, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was coated on a silicon wafer using a spin coater. The resist solution was applied on a hot plate at 90 DEG C for 1.5 minutes, at 110 DEG C for 1.5 minutes, Then, the resist film was baked at 180 DEG C for 1 minute to form a resist film having a thickness of 1 mu m, and the dry etching rate was measured. The resist film was evaluated in the same manner as in Examples 1 to 5, Reference Examples 1 to 3, The dry etching rates of the films obtained from the resin composition for forming a microlens prepared in Comparative Examples 1 to 5 were determined.

[Measurement of glass transition temperature (Tg)] [

The resin compositions for forming microlenses prepared in Examples 1 to 5, Reference Examples 1 to 3, and Comparative Examples 1 to 5 were each coated on a silicon wafer using a spin coater, And baking was performed at 100 캜 for 1 minute and then at 230 캜 for 10 minutes to form a film having a thickness of 2 탆. These films were peeled off from the silicon wafer and measured using a differential scanning calorimeter DSC3100SR (manufactured by Mac Science Co., Ltd.). The evaluation results are shown in Table 1.

[Table 1]

From the results shown in Table 1, the film formed of the resin composition for forming a microlens of the present invention has high solvent resistance and high transparency, and has high heat resistance that is not colored even after heating at 260 占 폚. Further, in the etch-back method, when the lens pattern shape is faithfully transferred to the resin layer for the lower microlens, the dry etching rate X of the resist film is equal to the dry etching rate Y of the resin layer for the microlens (X: Y = 1: 0.8 to 1.2, preferably X: Y = 1: 0.9 to 1.1). However, the resin composition for forming a microlens of the present invention has a satisfactory result. In view of the micro-lens forming process and reliability as a permanent member, the Tg of the film formed of the resin composition for forming a microlens is preferably 200 DEG C or higher, more preferably 200 DEG C or more. 200 占 폚 is a temperature equal to or higher than the heating temperature necessary for forming the resist pattern on the film in the process of manufacturing the microlens with the film, and is also the temperature equal to or higher than the reflow temperature of the resist pattern. A film formed of the resin composition for forming a microlens of the present invention has a Tg of 200 DEG C or higher. On the other hand, it was found that the films formed from the resin compositions for forming a microlens prepared in Comparative Examples 1 to 5 did not satisfy all the characteristics. All the films formed from the resin compositions for forming a microlens prepared in Reference Examples 1 to 3 had a Tg of 200 deg.

Claims (7)

A resin composition for forming a microlens containing a copolymer having a structural unit represented by the following formula (1), (2), (3) and (4) and a solvent.
[Chemical Formula 1]

(Wherein X represents a cyclohexyl group or a phenyl group, Y represents a phenyl group, a biphenylyl group or a naphthyl group, each of R ⁰ independently represents a hydrogen atom or a methyl group, R ¹ represents a hydrogen atom, R ² represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, R ¹ and R ² may combine with each other to form a 4 to 7-membered heterocyclic hydrocarbon ring structure, R ³ represents a single bond or an alkylene group having 1 to 5 carbon atoms, the alkylene group may have an ether bond therein, and R ⁴ represents an organic group having 5 to 12 carbon atoms and having an epoxy group or an epoxy ring. )
The method according to claim 1,
Wherein the structural unit represented by the formula (3) is a structural unit represented by the following formula (3-1) or (3-2).
(2)

(Wherein R &lt; ⁰ &gt; and R &lt; ² &gt; are the same as defined in claim 1, and b represents 1 or 2.)
3. The method according to claim 1 or 2,
Wherein the structural unit represented by the formula (4) is a structural unit represented by the following formula (4-1), (4-2) or (4-3).
(3)

(Wherein R &lt; ⁰ &gt; is the same as defined in claim 1).
4. The method according to any one of claims 1 to 3,
Further comprising a surfactant.
5. The method according to any one of claims 1 to 4,
Wherein the copolymer has a weight average molecular weight of 1,000 to 100,000.
A cured film obtained from the resin composition for forming a microlens according to any one of claims 1 to 5.
A method for manufacturing a color filter substrate, comprising: applying a resin composition for forming a microlens according to any one of claims 1 to 5 on a color filter layer and baking to form a resin layer; forming a resist pattern on the resin layer using a resist composition A step of reflowing the resist pattern to form a lens pattern; and a step of etching back the resin layer using the lens pattern as an etching mask.