Composition for forming microlenses, method for manufacturing microlenses using the composition, cured film, solid-state image sensor, and imaging device

Abstract

To provide a microlens forming composition that has few restrictions on the type of usable resins and causes few residues during image development.SOLUTION: A microlens forming composition contains (A) an unsaturated group-containing alkali-soluble resin, (B) a photopolymerizable monomer having at least one ethylenically unsaturated bond, (C) an epoxy compound having two or more epoxy groups, (D) a photopolymerization initiator, (E) an ultraviolet absorber, and (F) a solvent. The mass of the (F) ultraviolet absorber is 3 mass% or more and 20 mass% or less relative to the total mass of the solid content.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition for forming microlenses, a method for manufacturing microlenses using the composition, a cured film obtained by curing the composition, a solid-state image sensor having the microlenses, and an imaging device. [Background technology]

[0002] Imaging devices such as digital cameras and camera-equipped mobile phones are equipped with solid-state image sensors, including CCD (charge-coupled device) image sensors and CMOS (complementarily metal-oxide semiconductor) image sensors. These image sensors have tiny focusing lenses (microlenses) to improve light-gathering efficiency. In recent years, there has been a demand for higher pixel counts, higher sensitivity, and miniaturization of these image sensors, and development of materials for microlenses that can meet these requirements is underway.

[0003] For example, Patent Document 1 discloses a resin composition used for forming microlens patterns, comprising an alkali-soluble resin and a photosensitive agent having a glass transition temperature (Tg) of 70°C or lower. According to Patent Document 1, the above resin composition can form fine dot patterns even by thermal flow at low temperatures (60-100°C). Patent Document 1 also states that the above resin composition can form microlens patterns by positive-type pattern formation that removes the exposed areas.

[0004] Furthermore, Patent Document 2 discloses a siloxane resin composition comprising a siloxane resin, metal-containing particles, and a polymerizable compound having an ethylenically unsaturated double bond. According to Patent Document 2, the above siloxane resin composition can further improve light resistance while maintaining a high refractive index of the cured product of the siloxane resin composition by setting the ratio of Ti and Zr contained in the metal-containing particles within a specific range. Patent Document 2 also states that the above siloxane resin composition can form a microlens pattern by forming a negative-type pattern that removes unexposed areas. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-100793 [Patent Document 2] Japanese Patent Publication No. 2019-173016 [Overview of the project] [Problems that the invention aims to solve]

[0006] As described in Patent Documents 1 and 2, both resin compositions capable of forming positive patterns and resin compositions capable of forming negative patterns are known for forming microlenses.

[0007] However, according to the inventors' findings, conventional resin compositions described in Patent Documents 1 and 2, etc., have the problem of easily generating residue during development. Furthermore, when the distance between lenses is narrow, this residue can cause the microlenses to stick together. On the other hand, resin compositions for forming microlenses are also required to have good adhesion of the formed microlens pattern to the substrate.

[0008] The present invention has been made in view of the above, and aims to provide a microlens forming composition that has fewer limitations on the resin that can be used, produces less residue during development, and can form a microlens pattern with good adhesion to a substrate; a method for manufacturing microlenses using the composition; a cured film obtained by curing the composition; a solid-state image sensor having the microlenses; and an imaging device having the solid-state image sensor. [Means for solving the problem]

[0009] The microlens-forming composition according to the present invention is a microlens-forming composition for forming a microlens pattern, the microlens-forming composition comprising (A) an alkali-soluble resin containing an unsaturated group, (B) a photopolymerizable monomer having at least one ethylenically unsaturated bond, (C) an epoxy compound having two or more epoxy groups, (D) a photopolymerization initiator, (E) an ultraviolet absorber, and (F) a solvent, wherein the content of (E) the ultraviolet absorber is 3% by mass or more and 20% by mass or less based on the total mass of solids.

[0010] The method for manufacturing a microlens according to the present invention includes: a coating layer formation step of applying and drying the above-mentioned microlens forming composition to form a coating film of the microlens forming composition; an exposure step of irradiating a part of the coating film with radiation through a photomask; a developing step of developing the irradiated coating film and removing the unexposed portion; and a heat flow step of heat-curing the exposed portion after development by heat flow processing the exposed portion into a microlens shape.

[0011] Another method for manufacturing a microlens according to the present invention includes: a resin layer forming step of applying the above-mentioned microlens forming composition, irradiating it with radiation and curing it to form a resin layer of the microlens forming composition; a step of forming an etching resist layer on the surface of the resin layer; an exposure step of irradiating a part of the etching resist layer with radiation through a photomask; a developing step of developing the etching resist layer that has been irradiated with radiation; a thermal flow step of thermally flowing the exposed portion after development to process the exposed portion into a microlens shape; and a transfer step of dry etching the resin layer using the exposed portion after thermal flow as a mask layer and transferring the shape of the mask layer to the resin layer.

[0012] Another method for manufacturing a microlens according to the present invention includes: a coating film forming step of applying the above-mentioned microlens forming composition onto a lens material layer and drying it to form a coating film of the microlens forming composition; an exposure step of irradiating a part of the coating film with radiation through a photomask; a developing step of developing the irradiated coating film and removing the unexposed portion; a mask layer forming step of heat-curing the developed coating film by thermal flow while processing the coating film into a microlens shape to form a mask layer having a microlens pattern; and a transfer step of dry etching the lens material layer and the mask layer to transfer the shape of the mask layer to the lens material layer.

[0013] The cured film according to the present invention is obtained by curing the above-mentioned microlens-forming composition.

[0014] The microlens according to the present invention is made of the above-mentioned cured film.

[0015] The solid-state image sensor according to the present invention includes the above-mentioned microlenses.

[0016] The imaging device according to the present invention has the above-mentioned solid-state image sensor. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a micro-lens forming composition with few limitations on the resin that can be used and with little residue generated during development, a method for manufacturing a micro-lens using the composition, a cured film obtained by curing the composition, a solid-state imaging device provided with the micro-lens, and an imaging device having the solid-state imaging device.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. In the present invention, when the content of each component has a zero in the first decimal place, the notation after the decimal point may be omitted.

[0019] 1. Micro-lens forming composition The micro-lens forming composition according to an embodiment of the present invention contains (A) an unsaturated group-containing alkali-soluble resin, (B) a photopolymerizable monomer having at least one ethylenically unsaturated bond, (C) an epoxy compound having two or more epoxy groups, (D) a photopolymerization initiator, (E) an ultraviolet absorber, and (F) a solvent.

[0020] In the following description, “(meth)acrylic acid” means both acrylic acid and methacrylic acid, “(meth)acrylate” means both acrylate and methacrylate, and “(meth)acryloyl” means both acryloyl and methacryloyl.

[0021] [Component (A)] Component (A) is an unsaturated group-containing alkali-soluble resin. By including component (A), the micro-lens forming composition can be imparted with solubility in alkali development.

[0022] The unsaturated group-containing alkali-soluble resin as component (A) preferably has a polymerizable unsaturated group and an acidic group for expressing alkali solubility in one molecule, and more preferably has both a polymerizable unsaturated group and a carboxy group. With such a resin, it can be widely used without particular limitation.

[0023] From the viewpoint of improving adhesion to the substrate, the above component (A) is preferably an unsaturated group-containing alkali-soluble resin represented by the following general formula (1) (hereinafter also simply referred to as "alkali-soluble resin represented by general formula (1)").

[0024] [ka]

[0025] In formula (1), Ar is independently an aromatic hydrocarbon group having 6 to 14 carbon atoms, and a portion of the bonded hydrogen atoms may be substituted with a group selected from the group consisting of a linear or branched alkyl group having 1 to 10 carbon atoms, an aryl group or arylalkyl group having 6 to 10 carbon atoms, a cycloalkyl group or cycloalkylalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and a halogen group. R1 is independently an alkylene group having 2 to 4 carbon atoms, and l is independently a number from 0 to 3. G is independently a (meth)acryloyl group, a substituent represented by the following general formula (2) or the following general formula (3), and Y is a tetravalent carboxylic acid residue. Z is independently a hydrogen atom or a substituent represented by the following general formula (4), and one or more are substituents represented by the following general formula (4). n is a number with an average value from 1 to 20.

[0026] [ka]

[0027] [ka]

[0028] In formulas (2) and (3), R2 is a hydrogen atom or a methyl group, R3 is a divalent alkylene group or alkylarylene group having 2 to 10 carbon atoms, R4 is a divalent saturated or unsaturated hydrocarbon group having 2 to 20 carbon atoms, and p is a number from 0 to 10.

[0029] [ka]

[0030] In formula (4), W is a divalent or trivalent carboxylic acid residue, and m is a number of 1 or 2.

[0031] Next, a method for producing the alkali-soluble resin represented by the above general formula (1) will be described in detail.

[0032] First, an epoxy compound (a) having a bisarylfluorene skeleton with several oxyalkylene groups in one molecule, represented by the following general formula (5) (hereinafter also simply referred to as "epoxy compound (a) represented by general formula (5)") is reacted with (meth)acrylic acid, or one or both of the (meth)acrylic acid derivatives represented by the following general formula (6) or the following general formula (7) to obtain a diol compound containing polymerizable unsaturated groups. The bisarylfluorene skeleton is preferably a bisnaphthol fluorene skeleton or a bisphenol fluorene skeleton.

[0033] [ka]

[0034] In formula (5), Ar is independently an aromatic hydrocarbon group having 6 to 14 carbon atoms, and a portion of the bonded hydrogen atoms may be substituted with a group selected from the group consisting of alkyl groups having 1 to 10 carbon atoms, aryl or arylalkyl groups having 6 to 10 carbon atoms, cycloalkyl or cycloalkylalkyl groups having 3 to 10 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, and halogen groups. R1 is independently an alkylene group having 2 to 4 carbon atoms, and l is independently a number from 0 to 3.

[0035] [ka]

[0036] [ka]

[0037] In formulas (6) and (7), R2 is a hydrogen atom or a methyl group, R3 is a divalent alkylene group or alkylarylene group having 2 to 10 carbon atoms, R4 is a divalent saturated or unsaturated hydrocarbon group having 2 to 20 carbon atoms, and p is a number from 0 to 10.

[0038] The reaction between the epoxy compound (a) represented by the above general formula (5) and the above (meth)acrylic acid or (meth)acrylic acid derivative can be carried out using known methods. For example, Japanese Patent Application Publication No. 4-355450 describes that a diol compound containing a polymerizable unsaturated group can be obtained by using about 2 moles of (meth)acrylic acid for 1 mole of an epoxy compound having two epoxy groups. In the present invention, the compound obtained by the above reaction is a diol (d) containing a polymerizable unsaturated group represented by the following general formula (8) (hereinafter also simply referred to as "diol (d) represented by general formula (8)").

[0039] [ka]

[0040] In formula (8), Ar is independently an aromatic hydrocarbon group having 6 to 14 carbon atoms, and a portion of the bonded hydrogen atoms may be substituted with a group selected from the group consisting of alkyl groups having 1 to 10 carbon atoms, aryl groups or arylalkyl groups having 6 to 10 carbon atoms, cycloalkyl groups or cycloalkylalkyl groups having 3 to 10 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, and halogen groups. G is independently a (meth)acryloyl group, a substituent represented by the following general formula (2) or the following general formula (3), R1 is independently an alkylene group having 2 to 4 carbon atoms, and l is independently a number from 0 to 3.

[0041] [ka]

[0042] [ka]

[0043] In formulas (2) and (3), R2 is a hydrogen atom or a methyl group, R3 is a divalent alkylene group or alkylarylene group having 2 to 10 carbon atoms, R4 is a divalent saturated or unsaturated hydrocarbon group having 2 to 20 carbon atoms, and p is a number from 0 to 10.

[0044] In the synthesis of the diol (d) represented by the above general formula (8), and the subsequent reaction with a polycarboxylic acid or its anhydride to produce an alkali-soluble resin represented by the above general formula (1), the reaction is usually carried out in a solvent with a catalyst as needed.

[0045] Examples of solvents include cellosolve solvents such as ethyl cellosolve acetate and butyl cellosolve acetate; high-boiling-point ether or ester solvents such as diglyme, ethyl carbitol acetate, butyl carbitol acetate, and propylene glycol monomethyl ether acetate; and ketone solvents such as cyclohexanone and diisobutyl ketone. There are no particular restrictions on the reaction conditions, such as the solvent and catalyst used, but it is preferable to use a solvent that does not contain hydroxyl groups and has a boiling point higher than the reaction temperature as the reaction solvent.

[0046] Furthermore, it is preferable to use a catalyst in the reaction between epoxy groups and carboxyl or hydroxyl groups. For example, Japanese Patent Publication No. 9-325494 describes catalysts such as ammonium salts including tetraethylammonium bromide and triethylbenzylammonium chloride, and phosphines including triphenylphosphine and tris(2,6-dimethoxyphenyl)phosphine.

[0047] Next, by reacting the diol (d) represented by the general formula (8) with a dicarboxylic acid or tricarboxylic acid or its acid anhydride (b) and a tetracarboxylic acid or its acid dianhydride (c), an alkali-soluble resin represented by the general formula (1) can be obtained, which has a polymerizable unsaturated group and an acidic group for exhibiting alkali solubility in one molecule.

[0048] The acid component used to synthesize the alkali-soluble resin represented by the above general formula (1) is a polyvalent acid component that can react with the hydroxyl group in the diol (d) molecule represented by the above general formula (8), and it is necessary to use a dicarboxylic acid or tricarboxylic acid or their acid monoanhydride (b) in combination with a tetracarboxylic acid or its acid dianhydride (c). The carboxylic acid residue of the above acid component may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Furthermore, these carboxylic acid residues may contain bonds containing heteroatoms such as -O-, -S-, and carbonyl groups.

[0049] Examples of the above-mentioned dicarboxylic acids or tricarboxylic acids or their acid monoanhydrides (b) include chain-type hydrocarbon dicarboxylic acids or tricarboxylic acids, alicyclic hydrocarbon dicarboxylic acids or tricarboxylic acids, aromatic dicarboxylic acids or tricarboxylic acids, or their acid monoanhydrides.

[0050] Examples of the above-mentioned chain-like hydrocarbon dicarboxylic acids or tricarboxylic acids include succinic acid, acetylsuccinic acid, maleic acid, adipic acid, itaconic acid, azelaic acid, citramalic acid, malonic acid, glutaric acid, citric acid, tartaric acid, oxoglutaric acid, pimelic acid, sebacic acid, suberic acid, diglycolic acid, and the above-mentioned chain-like hydrocarbon dicarboxylic acids or tricarboxylic acids to which any substituent has been introduced.

[0051] Furthermore, examples of the above-mentioned alicyclic hydrocarbon dicarboxylic acids or tricarboxylic acids include cyclobutanedicarboxylic acid, cyclopentanedicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, norbornanedicarboxylic acid, chloridenic acid, hexahydrotrimellitic acid, and the above-mentioned alicyclic hydrocarbon dicarboxylic acids or tricarboxylic acids to which any substituent has been introduced.

[0052] Furthermore, examples of the above aromatic dicarboxylic acids or tricarboxylic acids include acid monoanhydrides such as phthalic acid, isophthalic acid, trimellitic acid, 1,8-naphthalenedicarboxylic acid, and 2,3-naphthalenedicarboxylic acid, as well as the above aromatic dicarboxylic acids or tricarboxylic acids to which any substituent has been introduced.

[0053] Among the above dicarboxylic acids or tricarboxylic acids or their acid monoanhydrides, succinic acid, itaconic acid, phthalic acid, trimellitic acid, tetrahydrophthalic acid, hexahydrotrimellitic acid, 1,8-naphthalenedicarboxylic acid, and 2,3-naphthalenedicarboxylic acid are preferred, and tetrahydrophthalic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, or their acid monoanhydrides are more preferred.

[0054] Furthermore, it is preferable to use an acid monoanhydride as the dicarboxylic acid or tricarboxylic acid or its acid anhydride (b). The acid monoanhydrides of the dicarboxylic acid or tricarboxylic acid described above may be used individually or in combination of two or more.

[0055] Furthermore, examples of the above-mentioned tetracarboxylic acid or its acid dianhydride (c) include chain-type hydrocarbon tetracarboxylic acids, alicyclic hydrocarbon tetracarboxylic acids, aromatic tetracarboxylic acids, or their acid dianhydrides.

[0056] Examples of the above-mentioned chain-type hydrocarbon tetracarboxylic acids include butanetetracarboxylic acid, pentanetetracarboxylic acid, hexanetetracarboxylic acid, and the above-mentioned chain-type hydrocarbon tetracarboxylic acids to which substituents such as alicyclic hydrocarbon groups and unsaturated hydrocarbon groups have been introduced.

[0057] Furthermore, examples of the above-mentioned alicyclic hydrocarbon tetracarboxylic acids include cyclobutanetetracarboxylic acid, cyclopentanetetracarboxylic acid, cyclohexanetetracarboxylic acid, cycloheptanetetracarboxylic acid, norbornanetetracarboxylic acid, and the above-mentioned alicyclic tetracarboxylic acids into which substituents such as chain hydrocarbon groups and unsaturated hydrocarbon groups have been introduced.

[0058] Examples of aromatic tetracarboxylic acids include pyromellitic acid, benzophenonetetracarboxylic acid, biphenyltetracarboxylic acid, diphenyl ethertetracarboxylic acid, diphenyl sulfonetetracarboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid, and naphthalene-2,3,6,7-tetracarboxylic acid.

[0059] In addition, aryl bis-trimellitic anhydride esters can also be used. Arilly bis-trimellitic anhydride esters are a group of compounds produced, for example, by the method described in International Publication No. 2010 / 074065, and are structurally acidic dianhydrides in which two hydroxyl groups of an aromatic diol (such as naphthalenediol, biphenol, or terphenyldiol) react with the carboxyl groups of two molecules of trimellitic anhydride to form an ester bond. These compounds will be referred to below as bis-trimellitic anhydride esters of aromatic diols.

[0060] Among the tetracarboxylic acids or their acid dianhydrides mentioned above, biphenyltetracarboxylic acid, benzophenonetetracarboxylic acid, diphenyl ethertetracarboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid, and naphthalene-2,3,6,7-tetracarboxylic acid are preferred, and biphenyltetracarboxylic acid, benzophenonetetracarboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid, and naphthalene-2,3,6,7-tetracarboxylic acid are more preferred. Furthermore, it is preferable to use an acid dianhydride as the tetracarboxylic acid or its acid dianhydride (c). In addition, bis-trimellitic anhydride ester of naphthalenediol can also be preferably used. Note that the tetracarboxylic acids or their acid dianhydrides and bis-trimellitic anhydrides of aromatic diols mentioned above may be used individually or in combination of two or more.

[0061] The reaction method between the diol (d) represented by the above general formula (8) and the acid components (b) and (c) is not particularly limited, and known methods can be employed. For example, Japanese Patent Publication No. 9-325494 describes a method of reacting epoxy (meth)acrylate with a tetracarboxylic dianhydride at a reaction temperature of 90 to 140°C.

[0062] Here, it is preferable to react the compound with a polymerizable unsaturated group-containing diol (d), dicarboxylic acid or tricarboxylic acid or their acid monoanhydride (b), or tetracarboxylic dianhydride (c) such that the terminal end of the compound is a carboxyl group, in a molar ratio of (d):(b):(c) = 1.0:0.01 to 1.0:0.2 to 1.0.

[0063] For example, when using acid monoanhydride (b) and acid dianhydride (c), it is preferable to react them such that the molar ratio of the amount of acid component [(b) / 2+(c)] to the amount of polymerizable unsaturated group-containing diol (d) is 0.5 to 1.0. Here, if the molar ratio is 0.5 or higher, the excess content of unreacted acid anhydride can be suppressed, thereby improving the long-term stability of the alkali-soluble resin composition. Also, if the molar ratio is 1.0 or lower, the excess content of unreacted polymerizable unsaturated group-containing diol can be suppressed, thereby improving the long-term stability of the alkali-soluble resin composition. Note that the molar ratios of each component (b), (c), and (d) can be arbitrarily changed within the above range in order to adjust the acid value and molecular weight of the alkali-soluble resin represented by general formula (1).

[0064] In the present invention, the content of component (A), which is an alkali-soluble resin represented by general formula (1), is preferably 10% by mass or more and 90% by mass or less, and more preferably 30% by mass or more and 80% by mass or less, relative to the total mass of solids. By setting the content of component (A) to 10% by mass or more, even fine patterns can be developed with excellent adhesion and the occurrence of pattern peeling can be suppressed, and by setting it to 90% by mass or less, good photocurability can be obtained, excellent contrast between exposed and unexposed areas during development, and sufficient photolithography can be obtained.

[0065] Furthermore, the acid value of the alkali-soluble resin represented by the above general formula (1) is preferably 50 mg KOH / g or more and 200 mg KOH / g, and more preferably 60 mg KOH / g or more and 150 mg KOH / g or less. When the acid value is 50 mg KOH / g or more, residue is less likely to remain during alkaline development, and when it is 200 mg KOH / g or less, the penetration of the alkaline developer does not become too fast, so peeling development can be suppressed. The acid value can be determined, for example, by titration with a 1 / 10 N-KOH aqueous solution using a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.).

[0066] Furthermore, the weight-average molecular weight (Mw) of the alkali-soluble resin represented by general formula (1) is preferably 1,000 to 40,000, more preferably 1,500 to 30,000, and even more preferably 2,000 to 15,000. When the weight-average molecular weight (Mw) is 1,000 or more, even fine patterns can be prevented from peeling off from the substrate. When the weight-average molecular weight (Mw) is 40,000 or less, the solubility of the unexposed areas in the alkaline developer is improved, and the generation of residue can be suppressed. The weight-average molecular weight (Mw) can be determined, for example, by gel permulation chromatography (GPC) "HLC-8220GPC" (manufactured by Tosoh Corporation).

[0067] Furthermore, other examples of resins preferred as component (A) include copolymers of (meth)acrylic acid, (meth)acrylic acid esters, etc., which have (meth)acryloyl groups and carboxyl groups. Examples of the above resins include unsaturated group-containing alkali-soluble resins obtained by copolymerizing (meth)acrylic acid esters containing glycidyl (meth)acrylate in a solvent, reacting a copolymer obtained with (meth)acrylic acid, and finally reacting it with an anhydride of a dicarboxylic acid or tricarboxylic acid. The above copolymer can be referenced from a copolymer described in Japanese Patent Publication No. 2014-111722, which consists of 20-90 mol% repeating units derived from diester glycerol with hydroxyl groups at both ends esterified with (meth)acrylic acid, and 10-80 mol% repeating units derived from one or more polymerizable unsaturated compounds copolymerizable thereto, with a number average molecular weight (Mn) of 2000-20000 and an acid value of 35-120 mgKOH / g, and an unsaturated group-containing alkali-soluble resin described in Japanese Patent Publication No. 2018-141968, which includes units derived from (meth)acrylic acid ester compounds and units having (meth)acryloyl groups and di or tricarboxylic acid residues, with a weight average molecular weight (Mw) of 3000-50000 and an acid value of 30-200 mgKOH / g.

[0068] Furthermore, the alkali-soluble resin containing unsaturated groups of component (A) may be used alone or in combination of two or more types.

[0069] Next, the above-mentioned components (B) to (G) contained in the microlens-forming composition according to one embodiment of the present invention will be described.

[0070] [(B) Component] Component (B) is a photopolymerizable monomer having at least one ethylenically unsaturated bond. Including component (B) can improve exposure sensitivity and developability.

[0071] (B) Examples of components include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol This includes (meth)acrylic acid esters such as tra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, glycerol(meth)acrylate, glycerol di(meth)acrylate, glycerol tri(meth)acrylate, sorbitol penta(meth)acrylate, sorbitol hexa(meth)acrylate, alkylene oxide-modified phosphazene hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, and dendrimer-type polyfunctional acrylates. These photopolymerizable monomers may be used individually or in combination of two or more.

[0072] The content of component (B) is preferably 1 to 200 parts by mass, more preferably 4 to 100 parts by mass, and even more preferably 10 to 70 parts by mass, per 100 parts by mass of component (A). When the content of component (B) is 1 part by mass or more per 100 parts by mass of component (A), the effect of improving exposure sensitivity and developability by component (B) is sufficiently achieved. Furthermore, when the content of component (B) is 200 parts by mass or less per 100 parts by mass of component (A), the concentration of acidic functional groups is sufficiently high, and good solubility in alkaline developer in the exposed area is obtained, so that the desired pattern can be formed.

[0073] [(C) component] Component (C) is an epoxy compound having two or more epoxy groups. By including component (C), a sufficient cross-linked structure can be formed, thereby improving chemical resistance.

[0074] Examples of component (C) include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol fluorene type epoxy compounds, bisnaphthol fluorene type epoxy compounds, diphenyl fluorene type epoxy compounds, phenol novolac type epoxy compounds, cresol novolac type epoxy compounds, phenol aralkyl type epoxy compounds, phenol novolac compounds containing a naphthalene skeleton (e.g., NC-7000L: manufactured by Nippon Kayaku Co., Ltd.), biphenyl type epoxy compounds (e.g., jERYX4000: manufactured by Mitsubishi Chemical Corporation, "jER" is a registered trademark of the company), naphthol aralkyl type epoxy compounds, trisphenolmethane type epoxy compounds (e.g., EPPN-501H: manufactured by Nippon Kayaku Co., Ltd.), tetrakisphenolethane type epoxy compounds, glycidyl ethers of polyhydric alcohols, glycidyl esters of polyhydric carboxylic acids, and copolymers of methacrylic acid and glycidyl methacrylate containing (meth)acrylic group-containing compounds with a (meth)acrylic group as a unit. Nomer copolymers, 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (e.g., Celoxide 2021P: manufactured by Daicel Corporation, "Celoxide" is a registered trademark of the company), butanetetracarboxylic acid tetra(3,4-epoxycyclohexylmethyl)-modified ε-caprolactone (e.g., Epolid GT401: manufactured by Daicel Corporation, "Epolid" is a registered trademark of the company), epoxy compounds having epoxycyclohexyl groups (e.g., HiREM-1: manufactured by Shikoku Chemicals Co., Ltd.) These include polyfunctional epoxy compounds having a dicyclopentadiene skeleton (e.g., HP7200 series: manufactured by DIC Corporation), 1,2-epoxy-4-(2-oxyranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (e.g., EHPE3150: manufactured by Daicel Corporation), epoxidized polybutadiene (e.g., NISSO-PBJP-100: manufactured by Nippon Soda Co., Ltd., "NISSO-PB" is a registered trademark of the company), epoxy compounds having a silicone skeleton, etc. These compounds may be used individually or in combination of two or more.

[0075] Among the components of (C), bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol fluorene type epoxy compounds, bisnaphthol fluorene type epoxy compounds, phenol novolac type epoxy compounds, cresol novolac type epoxy compounds, and biphenyl type epoxy compounds are preferred, with biphenyl type epoxy compounds being more preferred. By using biphenyl type epoxy compounds, it is possible to achieve both the mechanical strength and chemical resistance of the cured product that matches the required properties, and the patternability of the microlens-forming composition during photocuring, while also greatly increasing the freedom in designing the microlens-forming composition.

[0076] The epoxy equivalent of component (C) epoxy compound is preferably 100 g / eq or more and 300 g / eq or less, and more preferably 100 g / eq or more and 250 g / eq or less. Furthermore, the number average molecular weight (Mn) of component (C) epoxy compound is preferably 100 or more and 5000 or less. When the epoxy equivalent is 100 g / eq or more and the number average molecular weight (Mn) of the epoxy compound is 100 or more, a cured film with good solvent resistance can be obtained, and when the epoxy equivalent is 300 g / eq or less and the number average molecular weight (Mn) is 5000 or less, sufficient alkali resistance can be maintained even when an alkaline chemical solution is used in a subsequent process.

[0077] The epoxy equivalent of component (C) of the epoxy compound can be determined by titration with a 1 / 10N perchloric acid solution using a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.). The number-average molecular weight (Mn) of the epoxy compound can be determined, for example, by the gel permuration chromatography (GPC) "HLC-8220GPC" (manufactured by Tosoh Corporation).

[0078] The content of component (C) is preferably 1 part by mass or more and 30 parts by mass or less, and more preferably 3 parts by mass or more and 20 parts by mass or less, relative to the total mass of solids. By setting the content of the epoxy compound in component (C) to 1 part by mass or more, chemical resistance can be further enhanced, and by setting the content of the epoxy compound in component (C) to 30 parts by mass or less, sufficient adhesion to the substrate can be ensured.

[0079] [(D) component] Component (D) is a photopolymerization initiator. By including component (D), the reaction in the light-irradiated area proceeds sufficiently, reducing the solubility of the hardened area during development and allowing the formation of a desired fine pattern.

[0080] (D) Examples of components include 2-[4-(methylthio)benzoyl]-2-(4-morpholinyl)propane, 2-(o-chlorophenyl)-4,5-phenylbiimidazole, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)biimidazole, 2-(o-fluorophenyl)-4,5-diphenylbiimidazole, 2-(o-methoxyphenyl)-4,5-diphenylbiimidazole, 2,4,5-triarylbiimidazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl- Biimidazole compounds such as 1,2-biimidazole; halomethylthiazole compounds such as 2-trichloromethyl-5-styryl-1,3,4-oxadiazol, 2-trichloromethyl-5-(p-cyanostyryl)-1,3,4-oxadiaazole, and 2-trichloromethyl-5-(p-methoxystyryl)-1,3,4-oxadiaazole; 2,4,6-tris(trichloromethyl)-1,3,5-triazine, 2-methyl-4,6-bis(trichloromethyl)-1,3,5-triazine, and 2-phenyl-4,6-bis( Trichloromethyl)-1,3,5-triazine, 2-(4-chlorophenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4,5-trimethoxystyryl)-4,6-bis(trichloromethyl)-1, Halomethyl-s-triazine compounds such as 3,5-triazine, 2-(4-methylthiostyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine; 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(O-benzoyloxime) (Irgacure OXE01, manufactured by BASF Japan, "Irgacure" is a registered trademark of the company), 1-(4-phenylsulfanylphenyl)butane-1,2-dione-2-oxime-O-benzoate, 1-(4-methylsulfanylphenyl)butane-1,2-dione-2-oxime-O-acetate, 1-(4-methylsulfanylphenyl)butane-1-oneoxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-bicycloheptyl-1-oneoxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-adamantilmethane-1-oneoxime-O-benzoate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole- 3-yl]-adamantilmethane-1-oneoxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-tetrahydrofuranylmethane-1-oneoxime-O-benzoate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-tetrahydrofuranylmethane-1-oneoxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-thiophenylmethane-1-one Oxime-O-benzoate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-thiophenylmethane-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-molofonylmethane-1-one oxime-O-benzoate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-molofonylmethane-1-one oxime-O-acetate, 1-[9-ethyl-6-(2 -methylbenzoyl)-9H-carbazol-3-yl]-ethane-1-onoxime-O-bicycloheptane carboxylate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethane-1-onoxime-O-tricyclodecane carboxylate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethane-1-onoxime-O-adamantane carboxylate, 1-[4-(phenylsulfanyl)phenyl]octane-1,2-Dione=2-O-benzoyl oxime, 1-[9-ethyl-6-(2-methylbenzoyl)carbazole-3-yl]ethanone-O-acetyl oxime, (2-methylphenyl)(7-nitro-9,9-dipropyl-9H-fluoren-2-yl)-acetyl oxime, ethanone,1-[7-(2-methylbenzoyl)-9,9-dipropyl-9H-fluoren-2-yl]-1-(o-acetyl oxime), ethanone,1-(-9,9-dibutyl-7-nitro-9H-fluoren-2-yl)-1-O-acetyl oxime These include O-acyloxime compounds such as ethyloxime, ethanolone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyloxime) (Irgacure OXE02); benzyldimethyl ketal; anthraquinones such as 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, and 2,3-diphenylanthraquinone; and organic peroxides such as azobisisobutyronitrile, benzoyl peroxide, and cumene peroxide. These photopolymerization initiators may be used individually or in combination of two or more.

[0081] The content of component (D) is preferably 0.1 parts by mass or more and 30 parts by mass or less, and more preferably 0.3 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the total amount of components (A) and (B). When the content of component (D) is 0.1 parts by mass or more, photopolymerization can proceed more sufficiently, especially on the upper surface of the composition (the side irradiated by radiation). Furthermore, when the content of component (D) is 30 parts by mass or less, the curing reaction does not proceed to the depths of the coating film, making it easier to form a lens shape by heat flow.

[0082] [(E) component] Component (E) is an ultraviolet absorber. During negative pattern formation, after reaching the substrate interface, radiation spreading along the interface can cause the composition to harden at the substrate interface even in areas that were not irradiated. This can lead to the hardened resin spreading along the substrate interface, resulting in residual material. In contrast, the ultraviolet absorber absorbs the irradiated radiation, suppressing the spread of excess radiation along the substrate interface. Therefore, it is believed that including an ultraviolet absorber in the microlens forming composition can suppress the generation of residues specific to negative pattern formation. Furthermore, suppressing residues can also suppress the bonding between microlenses that occurs when the distance between lenses is narrow.

[0083] The ultraviolet absorber is preferably a compound having an absorption peak between wavelengths of 250 and 400 nm, and more preferably a compound that efficiently absorbs light at a wavelength of 365 nm.

[0084] Examples of component (E) include benzotriazole compounds, benzophenone compounds, triazine compounds, salicylic acid compounds, benzoate compounds, cinnamic acid derivatives, naphthalene derivatives, anthracene and its derivatives, dinaphthalene compounds, and phenanthroline compounds. These UV absorbers may be used individually or in combination of two or more.

[0085] In the present invention, the ultraviolet absorber is preferably selected from the group consisting of benzotriazole compounds, benzophenone compounds, and triazine compounds. These ultraviolet absorbers efficiently absorb the energy of radiation (e.g., ultraviolet rays) and suppress the spreading of excess radiation along the substrate interface, thereby reducing the occurrence of residue at the pattern edges after development.

[0086] Examples of benzotriazole compounds include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole, 2-( This includes 2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole, 2-(2'-hydroxy-4'-octoxyphenyl)benzotriazole, 2-{2'-hydroxy-3'-(3'',4'',5'',6''-tetrahydrophthalimidomethyl)-5'-methylphenyl}benzotriazole, C7-C9-alkyl-3-[3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]propion ether, etc.

[0087] Examples of benzophenone compounds include 4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, sodium 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, and hydroxydodecylbenzophenone.

[0088] Examples of triazine compounds include 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-isooctyloxyphenyl)-1,3,5-triazine, 2-[4((2-hydroxy-3-dodecyloxypropyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-((2-hydroxy-3-tridecyloxypropyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.

[0089] Furthermore, commercially available UV absorbers may be used. Examples of commercially available products include benzotriazole compounds such as TinuvinPS, 99-2, 326, 384-2, 900, 928, 1130 (BASF's "Tinuvin" is a registered trademark of the company), and Adekastab LA-24, 29, 31G, 32, 36 (ADEKA Corporation's "ADEKAstab" is a registered trademark of the company); benzophenone compounds such as UVINUL3049, 3050 (BASF's "UVINUL" is a registered trademark of the company), and Adekastab 1413; and triazine compounds such as Tinuvin400, 405, 460, Adekastab LA-46, and F70.

[0090] Furthermore, in the present invention, the ultraviolet absorber, which is component (E), is preferably a compound having a photosensitive functional group, and more preferably a benzotriazole compound, a benzophenone compound, or a triazine compound having a photosensitive functional group. From the viewpoint of increasing the reactivity with components (A) and (B), the above photosensitive functional group is preferably an ethylenically unsaturated group. Examples of the above ethylenically unsaturated group include acryloyl group, methacryloyl group, vinyl group, allyl group, styrenyl group, etc. Among these, acryloyl group and methacryloyl group, which have high reactivity with components (A) and (B), are preferred. By using an ultraviolet absorber having an ethylenically unsaturated group, the photosensitive reactive group of the ultraviolet absorber reacts with the unsaturated group-containing alkali-soluble resin or photopolymerizable monomer, and the ultraviolet absorber can be incorporated into the resin. As a result, from the viewpoint of reducing thermal damage to the substrate, even when the composition is cured at a low temperature such as 140°C, for example, the leaching of the ultraviolet absorber into the solvent can be suppressed, and the chemical resistance of the cured product can be improved. Furthermore, it can suppress discoloration caused by the precipitation of UV absorbers and sublimation during baking.

[0091] Examples of benzotriazole, benzophenone, and triazine compounds containing ethylenically unsaturated groups include 2-[2-hydroxy-5-(methacryloyloxyethyl)phenyl]-2H-benzotriazole.

[0092] Furthermore, examples of commercially available UV absorbers include RUVA-93 (manufactured by Otsuka Chemical Co., Ltd.).

[0093] The content of component (E) is 3% by mass or more and 20% by mass or less, preferably 4% by mass or more and 20% by mass or less, and more preferably 6 parts by mass or more and 18 parts by mass or less, relative to the total mass of solids. By setting the content of component (E) to 3% by mass or more, the amount of radiation spreading along the substrate interface can be reduced, thereby reducing the occurrence of residue at the pattern edges after development. By setting the content of component (E) to 20% by mass or less, the reaction in the irradiated area can be sufficiently advanced, so that the microlens forming composition can be sufficiently cured.

[0094] [(F) component] Component (F) is a solvent. By including component (F), a liquid microlens-forming composition containing the above-mentioned components (A) to (E) and (G) can be obtained.

[0095] Examples of solvents include alcohols such as methanol, ethanol, n-propanol, isopropanol, ethylene glycol, propylene glycol, 3-methoxy-1-butanol, ethylene glycol monobutyl ether, 3-hydroxy-2-butanone, and diacetone alcohol; terpenes such as α- or β-terpineol; ketones such as acetone, methyl ethyl ketone, cyclohexanone, and N-methyl-2-pyrrolidone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; methyl cellosolve, ethyl cellosolve, methyl carbitol, ethyl carbitol, butyl carbitol, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, and propylene glycol monomethyl ether. This includes glycol ethers such as noethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, and triethylene glycol monoethyl ether, as well as esters such as ethyl acetate, butyl acetate, ethyl lactate, 3-methoxybutyl acetate, 3-methoxy-3-butyl acetate, 3-methoxy-3-methyl-1-butyl acetate, cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate.

[0096] The content of component (F) is preferably 40% by mass or more and 80% by mass or less of the total mass of the microlens-forming composition. When the content of component (F) is 40% by mass or more, the viscosity can be made such that the microlens-forming composition can be easily applied to the substrate, and when it is 80% by mass or less, a coating film with excellent film thickness uniformity can be obtained.

[0097] [(G) component] Component (G) is a sensitizer. By including component (G), the curing reaction by the photopolymerization initiator (D) can be controlled with greater precision.

[0098] Examples of component (G) include benzophenones such as triethanolamine, triisopropanolamine, benzophenone, 4,4'-bisdimethylaminobenzophenone (Michler ketone), 4-phenylbenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4,4'-diethylaminobenzophenone; acetophenones such as acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p-tert-butylacetophenone, benzyldimethylketal; benzoin ethers such as benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether; 2-dimethylaminoethylbenzoic acid, 4-dimethylaminobenzoate ethyl, 4-dimethylaminobenzoate (n-butoxy)ethyl, 4-dimethylaminobenzoate isoamyl, 4-dimethylaminobenzoate 2-ethylhexyl, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 4-benzoyl-4'-methyl-diphenyl sulfide, acrylic benzophenone, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, and other benzophenone derivatives, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2- These include thioxanthone derivatives such as isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, and 1-chloro-4-propoxythioxanthone; aminobenzophenone derivatives such as 4,4'-bisdiethylaminobenzophenone; 10-butyl-2-chloroacridone, 2-ethylanthraquinone, 9,10-phenanthrenequinone, and camphorquinone. These sensitizers may be used individually or in combination of two or more.

[0099] Furthermore, the content of component (G) is preferably 0.5 parts by mass or more and 200 parts by mass or less, and more preferably 1 part by mass or more and 100 parts by mass or less, based on 100 parts by mass of the total of component (D). By setting the content of component (G) to 0.5 parts by mass or more, the photopolymerization initiator can be sufficiently activated by light irradiation, and by setting it to 200 parts by mass or less, the curing reaction by the photopolymerization initiator can be controlled with greater precision.

[0100] [Other ingredients] The microlens-forming composition of the present invention may optionally contain additives such as curing agents, curing accelerators, thermal polymerization inhibitors and antioxidants, chain transfer agents, plasticizers, fillers, leveling agents, defoaming agents, surfactants, coupling agents, and viscosity modifiers.

[0101] Examples of curing agents include amine compounds, polycarboxylic acid compounds, phenolic resins, amino resins, dicyandiamides, and Lewis acid complex compounds, which contribute to the curing of epoxy resins.

[0102] Examples of curing accelerators include tertiary amines, quaternary ammonium salts, tertiary phosphines, quaternary phosphonium salts, borate esters, Lewis acids, organometallic compounds, and imidazoles, which contribute to accelerating the curing of epoxy resins.

[0103] Examples of thermal polymerization inhibitors and antioxidants include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, phenothiazine, and hindered phenol compounds.

[0104] Examples of chain transfer agents include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, β-mercaptopropionic acid, 2-ethylhexyl-3-mercaptopropionate, n-octyl-3-mercaptopropionate, methoxybutyl-3-mercaptopropionate, stearyl-3-mercaptopropionate, trimethylolpropanetris(3-mercaptopropionate), and tris-[(3-mercaptopropionate). This includes thiol compounds such as putopropionyloxy)-ethyl]-isocyanurate, pentaerythritol tetrakis(3-mercaptobutyrate), pentaerythritol tetrakis(3-mercaptopropionate), tetraethylene glycol bis(3-mercaptopropionate), dipentaerythritol hexakis(3-mercaptopropionate), 3,3'-thiodipropionic acid, dithiodipropionic acid, and laurylthiopropionic acid.

[0105] Examples of plasticizers include dibutyl phthalate, dioctyl phthalate, and tricresyl phosphate. Examples of fillers include glass fiber, silica, mica, and alumina.

[0106] Examples of defoaming agents and leveling agents include silicone-based, fluorine-based, and acrylic compounds.

[0107] Examples of surfactants include fluorine-based surfactants and silicone-based surfactants.

[0108] Examples of coupling agents include 3-(glycidyloxy)propyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-ureidopropyltriethoxysilane.

[0109] The microlens-forming composition of the present invention can be obtained by mixing the above-mentioned components (A) to (G) and any other components and heating them.

[0110] 2. Method for producing microlens compositions The methods (1) to (3) for producing the microlens composition are described below.

[0111] [Method for manufacturing microlenses (1)] A method for manufacturing a microlens composition according to one embodiment of the present invention includes: (i) a coating layer formation step of applying the above-mentioned microlens forming composition and drying it to form a coating film of the microlens forming composition; (ii) an exposure step of irradiating a part of the coating film with radiation through a photomask; (iii) a development step of developing the irradiated coating film and removing the unexposed parts; and (iv) a heat flow step of heat-curing the exposed parts after development by heat flowing the exposed parts to process them into a microlens shape. Each step will be described below.

[0112] [Coating film layer formation process] The coating layer formation process involves applying the above-mentioned microlens-forming composition onto a substrate and drying it to form a coating layer.

[0113] The above-mentioned substrate can be one of known types. Examples of substrates include glass substrates, silicon wafers, plastic substrates, and substrates on which colored resists, overcoats, anti-reflective films, and various metal thin films are formed on their surfaces. Examples of plastic substrates include resin substrates made of plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and polyimide. The substrate may be provided with light-receiving elements such as photodiodes, light-emitting elements such as organic light-emitting elements, and dye-containing elements such as color filters.

[0114] A known coating method can be used to apply the microlens-forming composition. Examples of such coating methods include known solution immersion methods, spray methods, roller coaters, land coaters, slit coaters, and spinner machines. These methods allow the microlens-forming composition to be applied to a desired thickness.

[0115] A known drying method can be used to dry the microlens-forming composition applied by the method described above. This drying method can be carried out by heating with an oven, hot air blower, hot plate, infrared heater, etc., vacuum drying, or a combination thereof. The heating temperature and heating time of the resin film can be appropriately selected depending on the solvent used. The heating temperature and heating time are preferably, for example, 80 to 120°C for 1 to 10 minutes.

[0116] [Synthesis process] The exposure process involves irradiating a portion of the aforementioned coating layer with radiation via a photomask to photo-cur a portion of the coating (composition for forming microlenses).

[0117] The above-mentioned photomasks can be any known ones. Examples of photomasks include multi-tone masks such as halftone masks and graytone masks. In a graytone mask, a light-shielding area and a diffraction grating are formed on a translucent substrate. The diffraction grating has light-transmitting areas such as slits, dots, and meshes spaced at intervals less than or equal to the resolution limit of the light used for exposure, and this configuration controls the light transmittance. In a halftone mask, a light-shielding area and a semi-transparent area are formed on a translucent substrate. The semi-transparent area controls the transmittance of the light used for exposure.

[0118] Examples of radiation to be irradiated include visible light, ultraviolet light, far ultraviolet light, electron beams, and X-rays. Of the above radiations, ultraviolet light is preferred. Known exposure devices (ultra-high pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, far ultraviolet lamps, etc.) can be used as the radiation irradiation device. The wavelength of the radiation to be irradiated is preferably between 250 nm and 400 nm. The radiation exposure dose is 25 mJ / cm². 2 More than 3000mJ / cm 2 The following is preferable: 50 mJ / cm² 2 More than 2000mJ / cm 2 The following is more preferable:

[0119] [Development process] The development process involves alkaline development of the irradiated coating to remove the coating from the unexposed areas.

[0120] Examples of paint film development methods include shower development, spray development, dip development, and paddle development. These development methods can be carried out using commercially available developing machines or ultrasonic cleaners.

[0121] Examples of developers suitable for development include aqueous solutions of alkalis (basic compounds) such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, diethylaminoethanol, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5.4.0]-7-undecene, and 1,5-diazabicyclo[4.3.0]-5-nonane. Development conditions vary depending on the microlens-forming composition, but it is preferable to carry out development at a temperature of 20-30°C for 10-120 seconds.

[0122] [Thermal flow process] The thermal flow process involves applying thermal flow to the exposed area (coating) after development, causing it to melt and flow, thereby processing the exposed area into a microlens shape while simultaneously heating and hardening it.

[0123] The heat flow method for the exposed area after development can be carried out by known methods (heating using an oven, hot air blower, hot plate, infrared heater, etc., vacuum drying, or a combination thereof). The temperature of the heat flow is not particularly limited as long as it is the temperature at which the coating film melts and flows. The heat flow temperature is preferably 140 to 250°C for 10 to 120 minutes, and more preferably 180 to 230°C for 30 to 90 minutes.

[0124] By using the microlens-forming composition of the present invention, even when forming a microlens pattern by a negative-type photolithography method such as manufacturing method (1), the spreading of radiation along the substrate interface is suppressed, and the residue at the pattern edges after development is reduced. This suppresses the connection between microlenses, allowing for the formation of a microlens pattern with a better shape.

[0125] [Method for manufacturing microlenses (2)] The microlens-forming composition of the present invention can fully exhibit a residue-suppressing effect in the above manufacturing method (1), but it can also be suitably used for forming microlenses by the following manufacturing methods (2) and (3).

[0126] A method for manufacturing a microlens composition according to one embodiment of the present invention includes: (i) a resin layer forming step of applying the microlens forming composition, irradiating it with radiation, and curing it to form a resin layer of the microlens forming composition; (ii) a step of forming an etching resist layer on the surface of the resin layer; (iii) an exposure step of irradiating a part of the etching resist layer with radiation through a photomask; (iv) a developing step of developing the irradiated etching resist layer; (v) a thermal flow step of heat flowing the exposed area after development to process the exposed area into a microlens shape; and (vi) a transfer step of dry etching the resin layer using the exposed area after thermal flow as a mask layer and transferring the shape of the mask layer to the resin layer.

[0127] [Resin layer formation process] The resin layer formation step involves applying the above-mentioned microlens-forming composition to the surface of a substrate, irradiating it with radiation, and drying it to form a resin layer of the microlens-forming composition. In this step, before applying the microlens-forming composition, any irregularities on the surface of the substrate are filled in and flattened by applying a transparent resin by spin coating. Then, after applying the microlens-forming composition to the flattened surface of the substrate, radiation (e.g., ultraviolet light) is irradiated to heat-cur it and form a resin layer. The method of applying the microlens-forming composition, the method of irradiating the applied microlens-forming composition with radiation can be carried out in the same manner as the method used in the above-described manufacturing method (1). The above heat curing can be carried out by the usual method of heat curing (post-bake) of a composition containing an alkali-soluble resin and an epoxy resin.

[0128] [Process for forming an etching resist layer] The step of forming the etching resist layer is the step of forming an etching resist layer on the surface of the resin layer.

[0129] The components of the etching resist are not particularly limited, as long as their shape can be transferred to the resin layer as a mask layer in the transfer process described later. The etching resist may be a positive-type resist or a negative-type resist. Furthermore, known methods can be used to form the etching resist layer on the surface of the resin layer.

[0130] [Synthesis process] The exposure process involves irradiating a portion of the etching resist layer with radiation through a photomask to photo-cure that portion of the etching resist layer. The method for exposing the etching resist layer is the same as the method used in the manufacturing method (1) described above, and the temperature and other conditions can be appropriately changed according to the type of etching resist.

[0131] [Development process] The development process involves alkaline development of the etching resist layer that has been irradiated with radiation. If the etching resist is positive type, the exposed areas are removed; if the etching resist is negative type, the exposed areas are removed. The alkaline development method can be appropriately selected from known methods according to the type of etching resist.

[0132] [Thermal flow process] The thermal flow process involves applying thermal flow to the exposed areas of the etched resist layer after development, causing melt flow, and processing the exposed areas of the etched resist layer into a microlens shape. The thermal flow process can be carried out in the same manner as the method used in the above-described manufacturing method (1), with the temperature and other conditions appropriately changed according to the type of etched resist.

[0133] [Transfer process] The transfer process involves dry etching the resin layer using the exposed area of ​​the etching resist layer after heat flow as a mask layer, thereby transferring the shape of the mask layer to the resin layer.

[0134] The dry etching described above can be performed using known methods. Examples of dry etching methods include plasma etching, ion etching, reactive ion etching, and sputter etching. Known equipment can also be used for dry etching. Examples of gases that can be used for dry etching include fluorine-based gases such as CHF3, CF4, C2F6, C3F8, and SF6; chlorine-based gases such as Cl2 and BCl3; oxygen-based gases such as O2 and O3; reducing gases such as H2, NH3, CO, CO2, CH4, C2H2, C2H4, C2H6, C3H4, C3H6, C3H8, HF, HI, HBr, HCl, NO, NH3, and BCl3; and inert gases such as He, N2, and Ar. These gases can be used in mixtures.

[0135] [Method for manufacturing microlenses (3)] A method for manufacturing a microlens composition according to one embodiment of the present invention includes: (i) a coating film forming step of applying the microlens forming composition onto a lens material layer and drying it to form a coating film of the microlens forming composition; (ii) an exposure step of irradiating a part of the coating film with radiation through a photomask; (iii) a developing step of developing the irradiated coating film and removing the unexposed portion; (iv) a mask layer forming step of heat flowing the developed coating film to heat-cur it while processing the coating film into a microlens shape to form a mask layer having a microlens pattern; and (v) a transfer step of dry etching the lens material layer and the mask layer to transfer the shape of the coating film layer to the lens material layer.

[0136] [Coating film formation process] The coating film formation step involves applying the above-mentioned microlens-forming composition onto the lens material layer and drying it to form a coating film of the microlens-forming composition. At this time, the surface of the lens material layer is planarized in the same way as described in the microlens manufacturing method (2). The method of applying the microlens-forming composition and the method of drying the applied microlens-forming composition can be carried out in the same way as the method used in the manufacturing method (1) described above.

[0137] The lens material layer can be any layer made of a known lens material.

[0138] [Synthesis and Development Processes] The above steps (ii) exposure and (iii) development can be carried out in the same manner as described in the method for manufacturing microlenses (1).

[0139] [Mask layer formation process] The mask layer formation process involves heat-flowing and melt-flowing the developed coating film, thereby processing the coating film into a microlens shape while heat-curing it to form a mask layer having a microlens pattern. The heat flow of the coating film can be carried out in the same manner as the method used in the manufacturing method (1) described above.

[0140] [Transfer process] The transfer process can be carried out using the same dry etching method as used in the manufacturing method (2) described above.

[0141] By using the microlens-forming composition of the present invention, even when using a method in which the microlens-forming composition is used as a resist material, as in manufacturing method (3), the spreading of radiation along the interface between the lens layer and the etching resist layer is suppressed, thereby suppressing the generation of residue at the edges of the resist pattern. Therefore, by using the cured product of the microlens-forming composition of the present invention as a mask, the lens layer can be etched with high precision, and a microlens pattern with a better shape can be formed.

[0142] 3. Solid-state image sensor The solid-state image sensor of the present invention has the above-described microlenses. Because the solid-state image sensor of the present invention has the above-described microlenses, it is possible to increase the pixel count and sensitivity.

[0143] 4. Imaging device The imaging device of the present invention has the above-described solid-state image sensor. The imaging device of the present invention can obtain high-quality images because it has the above-described solid-state image sensor. [Examples]

[0144] The embodiments of the present invention will be specifically described below based on examples and comparative examples, but the present invention is not limited thereto.

[0145] First, we will explain the synthesis examples of the unsaturated group-containing alkali-soluble resin, which is component (A). Unless otherwise noted, the evaluation of the resin in these synthesis examples was performed as follows.

[0146] Note that when the same model of measuring instrument is used, the manufacturer's name is omitted from the second measurement onwards. Also, all glass substrates used in the examples have undergone the same treatment. Furthermore, when the first decimal place of the content of each component is 0, the decimal part may be omitted.

[0147] [Solid content concentration] The solid content concentration was determined using the following formula, which uses the weight [W1(g)] obtained by impregnating 1g of the resin solution obtained in the synthesis example into a glass filter [weight: W0(g)], and the weight [W2(g)] after heating at 160°C for 2 hours. Solid content concentration (weight%) = 100 × (W2-W0) / (W1-W0)

[0148] [Epoxy equivalent] The resin solution was dissolved in dioxane, then an acetic acid solution of tetraethylammonium bromide was added, and the result was obtained by titrating with a 1 / 10N perchloric acid solution using a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.).

[0149] [Acid value] The acid value was determined by dissolving the resin solution in dioxane and titrating it with a 1 / 10N-KOH aqueous solution using a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.).

[0150] [Molecular weight] The molecular weight was measured using gel permulation chromatography (GPC) "HLC-8220GPC" (manufactured by Tosoh Corporation, solvent: tetrahydrofuran, columns: TSKgelSuper H-2000 (2) + TSKgelSuper H-3000 (1) + TSKgelSuper H-4000 (1) + TSKgelSuper H-5000 (1) (manufactured by Tosoh Corporation), temperature: 40°C, rate: 0.6 ml / min), and the weight-average molecular weight (Mw) was calculated as a value converted to standard polystyrene (manufactured by Tosoh Corporation, PS-oligomer kit).

[0151] The abbreviations used in the synthesis examples are as follows: BPFE: Bisphenol fluorene type epoxy resin (an epoxy resin in which Ar is a benzene ring and l is 0, represented by general formula (1), epoxy equivalent 256 g / eq) BNFE: Bisnaphthol fluorene-type epoxy resin (an epoxy resin in which Ar is a naphthalene ring and l is 0, represented by general formula (1), epoxy equivalent 281 g / eq) BPDA: 3,3',4,4'-biphenyltetracarboxylic acid dianhydride THPA: 1,2,3,6-tetrahydrophthalic anhydride TPP: Triphenylphosphine AA: Acrylic acid PGMEA: Propylene glycol monomethyl ether acetate DCPMA: Dicyclopentanyl methacrylate GMA: Glycidyl methacrylate St: Styrene AIBN: Azobisisobutyronitrile TDMAMP: Trisdimethylaminomethylphenol HQ: Hydroquinone SA: Succinic anhydride TEA: Triethylamine

[0152] [Synthesis Example 1] BPFE (50.00 g, 0.10 mol), AA (14.07 g, 0.20 mol), TPP (0.26 g), and PGMEA (40.00 g) were charged into a 250 mL four-necked flask equipped with a reflux condenser, and the mixture was stirred at 100-105°C for 12 hours to obtain the reaction product. Subsequently, PGMEA (25.00 g) was added to the reaction product to adjust the solid content to 50% by mass.

[0153] Next, BPDA (14.37 g, 0.05 mol) and THPA (7.43 g, 0.05 mol) were added to the reaction product, and the mixture was stirred at 115-120°C for 6 hours to obtain a resin solution of unsaturated group-containing alkali-soluble resin (A)-1. The solid content concentration of the resin solution was 57.0% by mass, the acid value (based on solid content) was 96 mg KOH / g, and the Mw value determined by GPC analysis was 3600.

[0154] [Synthesis Example 2] BPFE (50.00 g, 0.10 mol), AA (14.07 g, 0.20 mol), TPP (0.26 g), and PGMEA (40.00 g) were charged into a 250 mL four-necked flask equipped with a reflux condenser, and the mixture was stirred at 100-105°C for 12 hours to obtain the reaction product. Subsequently, PGMEA (25.00 g) was added to the reaction product to adjust the solid content to 50% by mass.

[0155] Next, BPDA (10.06 g, 0.03 mol) and THPA (11.89 g, 0.08 mol) were added to the reaction product, and the mixture was stirred at 115-120°C for 6 hours to obtain a resin solution of polymerizable unsaturated group-containing alkali-soluble resin (A)-2. The solid content concentration of the resin solution was 57.0% by mass, the acid value (based on solid content) was 98 mg KOH / g, and the Mw value determined by GPC analysis was 2300.

[0156] [Synthesis Example 3] BPFE (50.00 g, 0.10 mol), AA (14.07 g, 0.20 mol), TPP (0.26 g), and PGMEA (40.00 g) were charged into a 250 mL four-necked flask equipped with a reflux condenser, and the mixture was stirred at 100-105°C for 12 hours to obtain the reaction product. Subsequently, PGMEA (25.00 g) was added to the reaction product to adjust the solid content to 50% by mass.

[0157] Next, BPDA (19.25 g, 0.07 mol) and THPA (0.30 g, 0.002 mol) were added to the reaction product, and the mixture was stirred at 115-120°C for 6 hours to obtain a resin solution of polymerizable unsaturated group-containing alkali-soluble resin (A)-3. The solid content concentration of the resin solution was 56.3% by mass, the acid value (based on solid content) was 97 mg KOH / g, and the Mw value determined by GPC analysis was 4700.

[0158] [Synthesis Example 4] In a 250 mL four-necked flask equipped with a reflux condenser, BNFE (50.00 g, 0.09 mol), AA (12.82 g, 0.20 mol), TPP (0.23 g), and PGMEA (40.00 g) were charged and stirred at 100-105°C for 12 hours to obtain the reaction product. Subsequently, PGMEA (25.00 g) was added to the reaction product to adjust the solid content to 50% by mass.

[0159] Next, BPDA (13.09 g, 0.04 mol) and THPA (6.77 g, 0.04 mol) were added to the reaction product, and the mixture was stirred at 115-120°C for 6 hours to obtain a resin solution of unsaturated group-containing alkali-soluble resin (A)-4. The solid content concentration of the resin solution was 56.1% by mass, the acid value (based on solid content) was 91 mg KOH / g, and the Mw value determined by GPC analysis was 3500.

[0160] [Synthesis Example 5] 300 g of PGMEA was placed in a 1 L four-necked flask equipped with a reflux condenser, and the flask system was purged with nitrogen before being heated to 120°C. A monomer mixture (DCPMA (77.1 g, 0.35 mol), GMA (49.8 g, 0.35 mol), and a mixture of St (31.2 g, 0.30 mol) in which AIBN (10 g) was dissolved) was added dropwise to the flask from a dropping funnel over 2 hours, and the mixture was stirred at 120°C for another 2 hours to obtain a copolymer solution.

[0161] Next, after replacing the flask system with air, AA (24.0 g, 95% of the glycidyl groups), TDMAMP (0.8 g), and HQ (0.15 g) were added to the obtained copolymer solution, and the mixture was stirred at 120°C for 6 hours to obtain a polymerizable unsaturated group-containing copolymer solution. SA (30.0 g, 90% of the moles of AA added) and TEA (0.5 g) were added to the obtained polymerizable unsaturated group-containing copolymer solution, and the mixture was reacted at 120°C for 4 hours to obtain the polymerizable unsaturated group-containing alkali-soluble copolymer resin solution (A)-5. The solid content concentration of the resin solution was 46.0% by mass, the acid value (based on solid content) was 76 mgKOH / g, and the Mw value determined by GPC analysis was 5300.

[0162] Microlens-forming compositions for Examples 1-11 and Comparative Examples 1-3 were prepared using the formulation amounts (in mass%) listed in Table 1. The formulation components used in Tables 1 and 2 are as follows.

[0163] (Alkali-soluble resin containing unsaturated groups) (A)-1: Resin solution obtained in Synthesis Example 1 (solid content concentration 57.0% by mass) (A)-2: Resin solution obtained in Synthesis Example 2 (solid content concentration 57.0% by mass) (A)-3: Resin solution obtained in Synthesis Example 3 (solid content concentration 56.3% by mass) (A)-4: Resin solution obtained in Synthesis Example 4 (solid content concentration 56.1% by mass) (A)-5: Resin solution obtained in Synthesis Example 5 (solid content concentration 46.0% by mass)

[0164] (Photopolymerizable monomer) (B): Dipentaerythritol penta / hexaacrylate mixture (KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd., "KAYARAD" is a registered trademark of the company)

[0165] (Epoxy compound) (C): Biphenyl-type epoxy resin (jER YX4000, manufactured by Mitsubishi Chemical Corporation, "jER" is a registered trademark of the company, epoxy equivalent 180-192 g / eq)

[0166] (Photopolymerization initiator) (D)-1: Omnirad907 (IGM Resins, manufactured by BV Corporation; "Omnirad" is a registered trademark of the company) (D)-2: Irgacure OXE-01 (manufactured by BASF, "Irgacure" is a registered trademark of the company)

[0167] (UV absorber) (E)-1: Tinuvin 384-2 (manufactured by BASF Japan, solids content 95% by mass, "Tinuvin" is a registered trademark of the company) (E)-2:Tinuvin400 (solid content concentration 85% by mass) (E)-3: ADEKA Stab 1413 (manufactured by ADEKA Corporation; "ADEKA Stab" is a registered trademark of the company) (E)-4: RUVA-93 (manufactured by Otsuka Chemical Co., Ltd.)

[0168] (solvent) (F): Propylene glycol monomethyl ether acetate (PGMEA)

[0169] (Sensitizer) (G): Mihläketone

[0170] [Table 1]

[0171] [Table 2]

[0172] [evaluation] The cured films obtained by curing the microlens-forming compositions of Examples 1 to 11 and Comparative Examples 1 to 3 shown in Tables 1 and 2 were evaluated as follows.

[0173] (Fabrication of substrates with hardened film for refractive index measurement) The microlens formation compositions shown in Tables 1 and 2 were applied to a 5-inch substrate (silicon wafer) using a spin coater to achieve a film thickness of 1.0 μm after heat curing. A dried film was then prepared by pre-baking at 100°C for 5 minutes using a hot plate. Subsequently, the dried film was heated with an ultra-high pressure mercury lamp (wavelength 365 nm, illuminance 30 mW / cm²). 2 ) 500 mJ / cm 2 After irradiating with ultraviolet light to perform a photocuring reaction (exposure), the substrate was fully cured (post-bake) at 230°C for 30 minutes using a hot air dryer to obtain a substrate with a cured film for refractive index measurement.

[0174] [Refractive Index Evaluation] An ellipsometer (manufactured by JAWoollam) was used to measure the refractive index of the substrate with the cured film at a wavelength of 633 nm after the curing process.

[0175] (Preparation of substrates with cured film for transmittance measurement) The microlens-forming compositions shown in Tables 1 and 2 were applied to a 125 mm x 125 mm glass substrate "#1737" (manufactured by Corning) (hereinafter referred to as "glass substrate") using a spin coater to achieve a film thickness of 1.0 μm after heat curing. A dried film was then prepared by pre-baking at 100°C for 5 minutes using a hot plate. Subsequently, the dried film was heated with an ultra-high pressure mercury lamp (wavelength 365 nm, illuminance 30 mW / cm²). 2 ) at 300 mJ / cm² 2 After irradiating with ultraviolet light to perform a photocuring reaction (exposure), the substrate with a cured film for transmittance measurement was obtained by performing post-bake curing at 230°C for 30 minutes using a hot air dryer.

[0176] [Transmittance evaluation] The transmittance of the substrate with the cured film after the curing process was measured at a wavelength of 400 nm using the UH4150 ultraviolet-visible-infrared spectrophotometer (manufactured by Hitachi High-Tech Science Corporation).

[0177] (Preparation of substrates with cured film for evaluating pattern adhesion and pattern edge residue) The composition for forming a microlens shown in Tables 1 and 2 was applied onto a 125 mm × 125 mm glass substrate using a spin coater so that the film thickness after heat curing treatment would be 2.0 μm, and a dry film was prepared by pre-baking at 100 °C for 5 minutes using a hot plate. Next, the above dry film was irradiated with ultraviolet light of 300 mJ / cm 2 with an ultra-high pressure mercury lamp (wavelength 365 nm, illuminance 30 mW / cm 2 ) to perform a photocuring reaction (exposure).

[0178] Next, the above exposed dry film (exposed film) was developed with a 0.8% TMAH (tetramethylammonium hydroxide) developer at 23 °C under a shower pressure of 1 kgf / cm 2 . After performing a development process for 10 seconds from the development time (break time = BT) when the pattern began to appear, spray water washing at 5 kgf / cm 2 was carried out to remove the unexposed portion of the above exposed film, thereby obtaining a dot pattern with a diameter of 5 μm on the glass substrate. Finally, the obtained dot pattern was subjected to post-curing (post-baking) at 230 °C for 30 minutes using a hot air dryer to obtain a substrate with a cured film for evaluating pattern adhesion and pattern edge residue.

[0179] [Evaluation of Pattern Adhesion] (Evaluation Method) The presence or absence of peeling of the 5-μm-diameter dot pattern (cured film) on the above substrate was observed using an optical microscope. Note that a result of △ or better was considered a pass.

[0180] (Evaluation Criteria) ○: No peeling was confirmed in the dot pattern △: Peeling was confirmed in a part of the dot pattern ×: All of the dot pattern was peeled off

[0181] [Evaluation of Residue at Pattern Edge] (Evaluation Method) The presence or absence of residue at the edge of the 5-μm-diameter dot pattern (cured film) on the above substrate was observed using a scanning electron microscope (SEM). Note that a result of △ or better was considered a pass.

[0182] (Evaluation Criteria) ○: No residue was observed at the pattern edges. △: Residue can be seen in part of the pattern edge. ×: There is significant residue at the edges of the pattern.

[0183] (Preparation of substrates with cured films for chemical resistance evaluation) The microlens-forming compositions shown in Tables 1 and 2 were applied to a glass substrate using a spin coater to achieve a film thickness of 2.0 μm after heat curing. A dried film was then prepared by pre-baking at 100°C for 5 minutes using a hot plate. Next, the dried film was heated with an ultra-high pressure mercury lamp (wavelength 365 nm, illuminance 30 mW / cm²). 2 ) at 300 mJ / cm² 2 After irradiating with ultraviolet light to perform a photocuring reaction (exposure), the substrate was cured (post-bake) using a hot air dryer at 180°C for 1 hour or 230°C for 30 minutes to obtain a substrate with a cured film for chemical resistance evaluation.

[0184] [Solvent resistance evaluation] (Evaluation method) The film thickness (L1) of the cured film after post-bake curing, and the film thickness (L2) of the same cured film after immersion in acetone for 10 minutes, followed by washing and drying, were measured using a stylus-type step shape measuring device "P-17" (manufactured by KLA-Tencor Co., Ltd.), and the residual film percentage (%) was calculated using the following formula. A result of △ or higher was considered acceptable. Remaining film rate (%)=L2 / L1×100

[0185] (Evaluation Criteria) ○: The residual film rate is 90% or higher. △: Residual film rate is 80% or more but less than 90%. ×: The residual film rate is less than 80%.

[0186] The evaluation results are shown in Tables 3 and 4.

[0187] [Table 3]

[0188] [Table 4]

[0189] As shown in Examples 1 to 11, it has been found that by using the microlens-forming resin composition of the present invention, a cured film having a high refractive index and high transmittance can be formed.

[0190] As shown in Examples 1 to 11, it was found that using a resin composition containing an ultraviolet absorber can suppress the generation of residues specific to negative pattern formation. This is thought to be because the ultraviolet absorber absorbs the irradiated radiation, suppressing the spread of excess radiation along the substrate interface, and preventing the composition from hardening at the interface with the substrate in areas that have not been irradiated.

[0191] Furthermore, as shown in Examples 4 to 11, it was found that by using an ultraviolet absorber having an ethylenically unsaturated group, the leaching of the ultraviolet absorber into the solvent can be suppressed, thereby improving the chemical resistance of the cured product. This is thought to be because the photosensitive reactive group of the ultraviolet absorber reacts with the unsaturated group-containing alkali-soluble resin or photopolymerizable monomer, allowing the ultraviolet absorber to be incorporated into the resin. [Industrial applicability]

[0192] The resin composition for forming microlenses of the present invention can be used in solid-state image sensors that require high pixel count and high sensitivity.

Claims

1. A microlens forming composition for forming a microlens pattern, (A) An alkali-soluble resin containing an unsaturated group represented by the following general formula (1), (B) A photopolymerizable monomer having at least one ethylenically unsaturated bond, (C) An epoxy compound having two or more epoxy groups, (D) Photopolymerization initiator, (E) An ultraviolet absorber selected from the group consisting of benzotriazole compounds, benzophenone compounds, triazine compounds, salicylic acid compounds, and benzoate compounds, wherein the benzophenone compound is 4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, sodium 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 4-dodecyloxy The triazine compound is selected from the group consisting of C-2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, and hydroxydodecylbenzophenone, and the triazine compound is selected from the group consisting of 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-isooctyloxyphenyl)-1,3,5-triazine, 2-[4((2-hydroxy-3-dodecyloxypropyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-((2-hydroxy-3-tridecyloxypropyl)-oxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and is an ultraviolet absorber. (F) Solvent and Includes, 【Chemistry 1】 (In formula (1), Ar is independently an aromatic hydrocarbon group having 6 to 14 carbon atoms, and a portion of the bonded hydrogen atoms may be substituted with a group selected from the group consisting of a linear or branched alkyl group having 1 to 10 carbon atoms, an aryl group or arylalkyl group having 6 to 10 carbon atoms, a cycloalkyl group or cycloalkylalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and a halogen group. １ Each of the following is an alkylene group having 2 to 4 carbon atoms, and each of the following is a number from 0 to 3. Each of the following is an independent (meth)acryloyl group, a substituent represented by the following general formula (2) or general formula (3), and Y is a tetravalent carboxylic acid residue. Each of the following is an independent hydrogen atom or a substituent represented by the following general formula (4), with one or more being substituents represented by the following general formula (4). n is a number with an average value from 1 to 20. 【Chemistry 2】 【Transformation 3】 (In formulas (2) and (3), R ２ R is a hydrogen atom or a methyl group, ３ R is a divalent alkylene group or alkylarylene group having 2 to 10 carbon atoms, ４ (where p is a divalent saturated or unsaturated hydrocarbon group having 2 to 20 carbon atoms, and p is a number from 0 to 10.) 【Chemistry 4】 (In formula (4), W is a divalent or trivalent carboxylic acid residue, and m is the number 1 or 2.) A composition for forming microlenses, wherein the content of the ultraviolet absorber (E) is 3% by mass or more and 20% by mass or less based on the total mass of the solids.

2. The microlens-forming composition according to claim 1, wherein the (E) ultraviolet absorber is selected from the group consisting of the benzotriazole compound, the benzophenone compound, and the triazine compound.

3. The (E) ultraviolet absorber is a microlens-forming composition according to claim 1 or claim 2, wherein the (E) ultraviolet absorber has an ethylenically unsaturated group.

4. The (A) unsaturated group-containing alkali-soluble resin has a weight-average molecular weight of 1,000 or more and 40,000 or less, and an acid value of 50 mg KOH / g or more and 200 mg KOH / g or less, the microlens-forming composition according to any one of claims 1 to 3.

5. (G) A microlens-forming composition according to any one of claims 1 to 4, comprising a sensitizer as component (G).

6. A coating layer forming step of applying and drying the microlens-forming composition according to any one of claims 1 to 5 to form a coating film of the microlens-forming composition, An exposure step in which a portion of the coating film is irradiated with radiation through a photomask, A developing step in which the irradiated coating film is developed and unexposed areas are removed, The process involves a heat flow step in which the exposed area after development is subjected to heat flow to process the exposed area into a microlens shape while simultaneously heating and curing it, A method for manufacturing microlenses, including

7. A resin layer forming step of applying the microlens forming composition according to any one of claims 1 to 5, irradiating it with radiation, and curing it to form a resin layer of the microlens forming composition, The steps include forming an etching resist layer on the surface of the resin layer, An exposure step in which a portion of the etching resist layer is irradiated with radiation through a photomask, A developing step for developing the etching resist layer irradiated with the aforementioned radiation, A heat flow step is performed to process the exposed area after development into a microlens shape by applying heat flow to it. A transfer step in which the exposed area after the heat flow is used as a mask layer to dry etch the resin layer and transfer the shape of the mask layer to the resin layer, A method for manufacturing microlenses, including

8. A coating film forming step involves applying the microlens-forming composition described in any one of claims 1 to 5 onto a lens material layer and drying it to form a coating film of the microlens-forming composition, An exposure step in which a portion of the coating film is irradiated with radiation through a photomask, A developing step in which the irradiated coating film is developed and unexposed areas are removed, A mask layer formation step involves heat-flowing the developed coating film to process it into a microlens shape while heating and curing it, thereby forming a mask layer having a microlens pattern. A transfer step of dry etching the lens material layer and the mask layer to transfer the shape of the mask layer to the lens material layer, A method for manufacturing microlenses, including

9. A cured film obtained by curing the microlens-forming composition according to any one of claims 1 to 5.

10. A microlens comprising the cured film described in claim 9.

11. A solid-state image sensor having microlenses as described in claim 10.

12. An imaging device having a solid-state image sensor as described in claim 11.

Images