JP6748663B2 - Curable composition, dry film, cured product and printed wiring board - Google Patents

Description

The present invention relates to a curable composition, a dry film, a cured product and a printed wiring board.

For example, in the production of printed wiring boards, a curable composition is generally adopted for forming a permanent coating such as a solder resist, and a dry film type composition or a liquid composition is developed as such a curable composition. (For example, Patent Document 1).

In recent years, due to the rapid progress of semiconductor components, electronic devices have tended to become lighter, thinner, shorter, smaller, and have higher performance and more functions. Following this trend, miniaturization, thinning, and multi-pinning of semiconductor packages have been put into practical use. Specifically, instead of IC packages called QFP (Quad Flat Pack Package) and SOP (Small Outline Package), BGA (Ball Grid Array), CSP (Chip Scale Package), etc. IC package called. Further, in recent years, an FC-BGA (flip chip ball grid array) has been put into practical use as an IC package having a higher density.

Japanese Patent Laid-Open No. 61-243869 (claims)

Further thinning is required for a permanent coating such as a solder resist formed on a printed wiring board (also referred to as a package substrate) used for the above IC package. However, when the film is made thinner, there is a problem that the strength of the cured film, such as the breaking strength, is relatively low, which is insufficient. For such a problem, it can be considered to increase the mixing ratio of the inorganic filler. However, in the case of a dry film made of a curable composition containing a large proportion of an inorganic filler, when laminated on a printed wiring board having a circuit pattern, the resin layer of the dry film is sufficiently brought into contact with the deep part of the circuit pattern. In some cases, it may become difficult and various characteristics such as insulation reliability may deteriorate.

Therefore, an object of the present invention is to provide a curable composition which is excellent in strength, has a high storage elastic modulus, and can form a cured product having a low coefficient of linear expansion (CTE), and which can provide a dry film having excellent laminate properties. It is intended to provide a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, and a printed wiring board having the cured product.

As a result of intensive studies by the present inventors, two types of inorganic fillers having different average particle diameters of 5 times or more are used in combination as the inorganic fillers to be added to the composition, and the mixing ratio of those inorganic fillers is set to a specific value or more. As a result, they have found that the above problems can be solved, and have completed the present invention.

That is, the curable composition of the present invention comprises (A) a curable component, (B-1) an inorganic filler, and (B-1) the inorganic filler having a different average particle size from each other (B-2). In the curable composition, the average particle size of the (B-1) inorganic filler is 5 times or more the average particle size of the (B-2) inorganic filler, and the (B-1) inorganic The total amount of the filler and the inorganic filler (B-2) is 45% by mass or more of the total mass of the solid content.

In the curable composition of the present invention, the average particle diameter of the (B-1) inorganic filler is preferably 8 times or more the average particle diameter of the (B-2) inorganic filler.

In the curable composition of the present invention, the maximum particle size of the inorganic filler (B-2) is preferably 500 nm or less.

In the curable composition of the present invention, the (B-1) inorganic filler preferably has an average particle size of 5 μm or less.

The curable composition of the present invention preferably contains the inorganic filler (B-1) and the inorganic filler (B-2) in a total amount of 80% by mass or more based on the total mass of the solid content.

In the curable composition of the present invention, the curable component (A) preferably contains at least a photocurable component, and further contains a photopolymerization initiator and an ultraviolet absorber.

In the curable composition of the present invention, the ultraviolet absorber is preferably carbon black.

The dry film of the present invention has a resin layer obtained from the curable composition.

The cured product of the present invention is characterized by being obtained by curing the curable composition or the resin layer of the dry film.

The printed wiring board of the present invention is characterized by having the cured product.

According to the present invention, a curable composition that is excellent in strength, has a high storage elastic modulus, and can form a cured product having a low coefficient of linear expansion (CTE), and that can obtain a dry film having excellent laminating properties. It is possible to provide a dry film having a resin layer obtained from the composition, a cured product of the resin layer of the composition or the dry film, and a printed wiring board having the cured product.

The curable composition of the present invention contains (A) a curable component, (B-1) an inorganic filler, and (B-1) an inorganic filler having an average particle diameter different from that of the (B-1) inorganic filler. A curable composition, wherein the (B-1) inorganic filler has an average particle diameter of 5 times or more the average particle diameter of the (B-2) inorganic filler, and the (B-1) inorganic filler. The total amount of the inorganic filler (B-2) is 45% by mass or more of the total mass of the solid content.

By increasing the mixing ratio of the mass of the inorganic filler in the total mass of the curable composition, it is possible to form a cured product having excellent strength, high storage elastic modulus, and low linear expansion coefficient (CTE). When the amount of the inorganic filler is increased by using a single inorganic filler, a problem of dry film laminating property occurs. Further, it becomes difficult to smooth the surface of the curable composition. These problems become remarkable when the compounding ratio of the inorganic filler in the total mass of the solid content of the curable composition is 45% by mass or more, and particularly 80% by mass or more.

In the present invention, as the inorganic filler, (B-1) contains an inorganic filler, (B-1) the inorganic filler and (B-2) an inorganic filler having a different average particle diameter, and (B-1) the average of the inorganic filler. By setting the particle diameter to 5 times or more the average particle diameter of the (B-2) inorganic filler, the gap between the (B-1) inorganic filler is filled with the (B-2) inorganic filler. Thereby, the remaining gap can be reduced, and a curable resin composition having a low resin content, that is, a high mass ratio of the filler in the total mass can be obtained. According to this curable resin composition, not only a cured product having a high mass ratio of the filler in the total mass and excellent strength can be obtained, but also the dry film laminating property is excellent. Further, the surface of the composition can be smoothed.

Further, in the curable composition of the present invention, there is no upper limit of the ratio of the mass of the inorganic filler in the total mass, but of the volume ratio of the (B-1) and (B-2) inorganic filler in the composition. The upper limit is, for example, 95% by volume or less. The curable composition of the present invention can be handled as a liquid ink.

Below, each component of the curable composition of this invention is demonstrated. In addition, in this specification, (meth)acrylate is a general term for acrylate, methacrylate, and a mixture thereof, and the same applies to other similar expressions.

[(A) Curable component]
The curable component (A) may be any one as long as it contains at least one of a photocurable reactive group and a thermosetting reactive group, but it contains both a photocurable reactive group and a thermosetting reactive group. Preferably. As the curable component (A), a photocurable component (A1) that contributes to a photocuring reaction by irradiation with light and a thermosetting component (A2) that contributes to a thermosetting reaction by heating are preferable.
Here, it is more preferable that the (A) curable component contains (A1) a photocurable component and (A2) a thermosetting component. Further, the curable composition of the present invention comprises (A1) a photocurable component, (A2) a thermosetting component, an alkali-soluble resin, and a compound having a plurality of cyclic ether groups or cyclic thioether groups in the molecule. It is more preferable that the composition contains
Further, the (A1) photo-curable component and the (A2) thermo-curable component may be a light- and heat-curable component that contributes to both the photo-curing reaction and the heat-curing reaction. The sexual component can be suitably used as the (A1) photocurable component and the (A2) thermosetting component.

((A1) Photocurable component)
The photocurable component (A1) is a compound having an ethylenically unsaturated group, and examples thereof include polymers, oligomers and monomers, and may be a mixture thereof. By including the photocurable component, the strength of the cured film can be improved. As the photocurable component (A1), one type may be used alone, or two or more types may be used in combination.
As the compound having an ethylenically unsaturated group, a photopolymerizable oligomer, a photopolymerizable vinyl monomer, etc., which are known and commonly used photocurable monomers, can be used.

Examples of the photopolymerizable oligomer include unsaturated polyester oligomers and (meth)acrylate oligomers. Examples of (meth)acrylate-based oligomers include epoxy (meth)acrylates such as phenol novolac epoxy (meth)acrylate, cresol novolac epoxy (meth)acrylate, and bisphenol type epoxy (meth)acrylate, urethane (meth)acrylate, epoxy urethane (meth). ) Acrylate, polyester (meth)acrylate, polyether (meth)acrylate, polybutadiene modified (meth)acrylate and the like.

As the photopolymerizable vinyl monomer, known and conventional ones, for example, styrene derivatives such as styrene, chlorostyrene, α-methylstyrene; vinyl esters such as vinyl acetate, vinyl butyrate or vinyl benzoate; vinyl isobutyl ether, vinyl- Vinyl ethers such as n-butyl ether, vinyl-t-butyl ether, vinyl-n-amyl ether, vinyl isoamyl ether, vinyl-n-octadecyl ether, vinyl cyclohexyl ether, ethylene glycol monobutyl vinyl ether, triethylene glycol monomethyl vinyl ether; acrylamide, (Meth)acrylamides such as methacrylamide, N-hydroxymethylacrylamide, N-hydroxymethylmethacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-butoxymethylacrylamide; triallyl isocyanurate, diallyl phthalate, Allyl compounds such as diallyl isophthalate; 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, etc. Of (meth)acrylic acid ester; hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, pentaerythritol tri(meth)acrylate and other hydroxyalkyl (meth)acrylates; methoxyethyl (meth)acrylate, ethoxyethyl Alkoxyalkylene glycol mono(meth)acrylates such as (meth)acrylate; ethylene glycol di(meth)acrylate, butanediol di(meth)acrylates, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di( Alkylene polyol poly(meth)acrylates such as (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate; diethylene glycol di(meth)acrylate, triethylene glycol di Polyoxyalkylene glycol poly(meth)acrylates such as (meth)acrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane tri(meth)acrylate A) acrylates; poly(meth)acrylates such as hydroxypivalic acid neopentyl glycol ester di(meth)acrylate; isocyanurate-type poly(meth)acrylates such as tris[(meth)acryloxyethyl]isocyanurate. Can be mentioned.

The photocurable component may be used alone or in combination of two or more. The compounding ratio of the photocurable component is, for example, 0 to 55% by mass, and preferably 0 to 50% by mass, in the solid content excluding the solvent of the entire composition.

(Photopolymerization initiator)
In the curable composition of the present invention, when the (A) curable component contains at least the (A1) photocurable component, it is preferable to further contain a photopolymerization initiator. As the photopolymerization initiator, any photopolymerization initiator known as a photopolymerization initiator or a photoradical generator can be used.

Examples of the photopolymerization initiator include bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, and bis-(2,2. 6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-( 2,6-Dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6- Bisacylphosphine oxides such as trimethylbenzoyl)-phenylphosphine oxide (IRGACURE819 manufactured by BASF Japan Ltd.); 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,4. 6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (IRGACURE TPO manufactured by BASF Japan Ltd.) 1-hydroxy-cyclohexyl phenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2- Hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-hydroxy-2-methyl-1-phenylpropane- 1-one and other hydroxyacetophenones; benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether and other benzoins; benzoin alkyl ethers; benzophenone, p-methyl Benzophenones such as benzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone; acetophenone, 2,2-dimetho Xy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino -1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl)-1-[ Acetophenones such as 4-(4-morpholinyl)phenyl]-1-butanone and N,N-dimethylaminoacetophenone; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethyl. Thioxanthones such as thioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, Anthraquinones such as 2-aminoanthraquinone; Ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; Benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethylbenzoate and p-dimethylbenzoic acid ethyl ester 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole -3-yl]-, 1-(O-acetyloxime) and other oxime esters; bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H- Titanocenes such as pyrrol-1-yl)phenyl)titanium and bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyr-1-yl)ethyl)phenyl]titanium; Phenyldisulfide 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide and the like can be mentioned. The photopolymerization initiators may be used alone or in combination of two or more. Among them, monoacylphosphine oxides and oxime esters (hereinafter, also referred to as monoacylphosphine oxide photopolymerization initiators and oxime ester photopolymerization initiators) are preferable, and 2,4,6-trimethylbenzoyldiphenylphosphine. Oxide, ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(O-acetyloxime) are more preferred.

The photopolymerization initiator may be used alone or in combination of two or more. The mixing ratio of the photopolymerization initiator is, for example, 0.01 to 30 parts by mass with respect to 100 parts by mass of the photocurable component.

((A2) Thermosetting component)
By including the thermosetting component (A2), the strength of the cured film can be improved. As the thermosetting component (A2), one type may be used alone, or two or more types may be used in combination.
As the thermosetting component (A2), any known one can be used. For example, melamine resin, benzoguanamine resin, melamine derivative, amino resin such as benzoguanamine derivative, isocyanate compound, blocked isocyanate compound, cyclocarbonate compound, epoxy compound, oxetane compound, episulfide resin, bismaleimide, carbodiimide resin, known alkali-soluble resin, etc. The thermosetting components of can be used. Particularly preferred are compounds having a plurality of cyclic ether groups or cyclic thioether groups (hereinafter abbreviated as cyclic (thio)ether groups) in the molecule and alkali-soluble resins.

The compound having a plurality of cyclic (thio)ether groups in the molecule is preferably a compound having a plurality of 3-, 4- or 5-membered cyclic (thio)ether groups in the molecule, for example, in the molecule Examples thereof include compounds having a plurality of epoxy groups, that is, polyfunctional epoxy compounds, compounds having a plurality of oxetanyl groups in the molecule, ie, polyfunctional oxetane compounds, compounds having a plurality of thioether groups in the molecule, that is, episulfide resins.

As the polyfunctional epoxy compound, epoxidized vegetable oil; bisphenol A type epoxy resin; hydroquinone type epoxy resin; bisphenol type epoxy resin; thioether type epoxy resin; brominated epoxy resin; novolac type epoxy resin; biphenol novolac type epoxy resin; bisphenol F Type epoxy resin; hydrogenated bisphenol A type epoxy resin; glycidyl amine type epoxy resin; hydantoin type epoxy resin; alicyclic epoxy resin; trihydroxyphenylmethane type epoxy resin; bixylenol type or biphenol type epoxy resin or a mixture thereof; Bisphenol S type epoxy resin; Bisphenol A novolac type epoxy resin; Tetraphenylolethane type epoxy resin; Heterocyclic epoxy resin; Diglycidyl phthalate resin; Tetraglycidyl xylenoylethane resin; Naphthalene group-containing epoxy resin; Dicyclopentadiene skeleton Examples of the epoxy resin include a glycidyl methacrylate copolymer epoxy resin, a cyclohexylmaleimide and glycidyl methacrylate copolymer epoxy resin, an epoxy-modified polybutadiene rubber derivative, a CTBN-modified epoxy resin, and the like, but are not limited thereto. .. These epoxy resins may be used alone or in combination of two or more. Among these, novolac type epoxy resin, bisphenol type epoxy resin, bixylenol type epoxy resin, biphenol type epoxy resin, biphenol novolac type epoxy resin, naphthalene type epoxy resin or a mixture thereof is particularly preferable.

Examples of the polyfunctional oxetane compound include bis[(3-methyl-3-oxetanylmethoxy)methyl]ether, bis[(3-ethyl-3-oxetanylmethoxy)methyl]ether, 1,4-bis[(3- Methyl-3-oxetanylmethoxy)methyl]benzene, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, (3-methyl-3-oxetanyl)methyl acrylate, (3-ethyl-3-) Oxetanyl)methyl acrylate, (3-methyl-3-oxetanyl)methyl methacrylate, polyfunctional oxetanes such as (3-ethyl-3-oxetanyl)methyl methacrylate and their oligomers or copolymers, as well as oxetane alcohol and novolak resin , Poly(p-hydroxystyrene), cardo type bisphenols, calixarenes, calixresorcinarenes, etherified products with resins having a hydroxyl group such as silsesquioxane, and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth)acrylate may be used.

Examples of the compound having a plurality of cyclic thioether groups in the molecule include bisphenol A type episulfide resin. Further, an episulfide resin in which an oxygen atom of an epoxy group of a novolac type epoxy resin is replaced with a sulfur atom by using the same synthetic method can be used.

Examples of amino resins such as melamine derivatives and benzoguanamine derivatives include methylolmelamine compounds, methylolbenzoguanamine compounds, methylolglycoluril compounds and methylolurea compounds.

As the isocyanate compound, a polyisocyanate compound can be blended. Examples of the polyisocyanate compound include 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate and Aromatic polyisocyanates such as 2,4-tolylene isocyanate dimer; Aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis(cyclohexyl isocyanate) and isophorone diisocyanate; Examples thereof include alicyclic polyisocyanates such as bicycloheptane triisocyanate; and adducts, burettes and isocyanurates of the above-mentioned isocyanate compounds.

As the blocked isocyanate compound, an addition reaction product of an isocyanate compound and an isocyanate blocking agent can be used. Examples of the isocyanate compound capable of reacting with the isocyanate blocking agent include the above-mentioned polyisocyanate compound and the like. Examples of the isocyanate blocking agent include phenol-based blocking agents; lactam-based blocking agents; active methylene-based blocking agents; alcohol-based blocking agents; oxime-based blocking agents; mercaptan-based blocking agents; acid amide-based blocking agents; imide-based blocking agents; Amine blocking agents; imidazole blocking agents; imine blocking agents and the like.

(Thermosetting catalyst)
The curable composition of the present invention preferably contains a thermosetting catalyst. Examples of the thermosetting catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- Imidazole derivatives such as (2-cyanoethyl)-2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzyl. Examples thereof include amines, amine compounds such as 4-methyl-N,N-dimethylbenzylamine, hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide, and phosphorus compounds such as triphenylphosphine. Further, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino. S-triazine derivatives such as -S-triazine/isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine/isocyanuric acid adduct can also be used, and preferably as the adhesion-imparting agent. A compound that also functions is used in combination with a thermosetting catalyst.
The thermosetting catalyst may be used alone or in combination of two or more. The mixing ratio of the thermosetting catalyst is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the thermosetting component.

Further, the thermosetting component (A2) preferably contains an alkali-soluble resin having an alkali-soluble group. Examples of the alkali-soluble resin include a compound having two or more phenolic hydroxyl groups, a carboxyl group-containing resin, a compound having a phenolic hydroxyl group and a carboxyl group, and a compound having two or more thiol groups. Above all, it is preferable that the alkali-soluble resin is a carboxyl group-containing resin or a phenol resin because the adhesion to the base is improved. In particular, the alkali-soluble resin is more preferably a carboxyl group-containing resin because of its excellent developability. The carboxyl group-containing resin is preferably a carboxyl group-containing photosensitive resin having an ethylenically unsaturated group, but may be a carboxyl group containing resin having no ethylenically unsaturated group. When the alkali-soluble resin has an ethylenically unsaturated group, it also functions as a photocurable component and corresponds to the above-mentioned photo- and thermosetting components. When the curable composition of the present invention contains an alkali-soluble resin, it may be used not only for alkali development but also for non-alkali development.

Specific examples of the carboxyl group-containing resin include compounds (both oligomer and polymer) listed below.

(1) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth)acrylic acid and an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth)acrylate and isobutylene.

(2) Diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates, and carboxy group-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, and polycarbonate-based polyols and polyether-based polyols A carboxyl group-containing urethane resin obtained by a polyaddition reaction of a diol compound such as a polyol, a polyester polyol, a polyolefin polyol, an acrylic polyol, a bisphenol A alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

(3) Diisocyanate compounds such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates, and polycarbonate-based polyols, polyether-based polyols, polyester-based polyols, polyolefin-based polyols, acrylic-based polyols, bisphenol A-based Alkylene oxide adducts A urethane resin containing a terminal carboxyl group obtained by reacting an acid anhydride with the terminal of a urethane resin by a polyaddition reaction of a diol compound such as a diol compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

(4) Diisocyanate and a bifunctional epoxy resin such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, biphenol type epoxy resin ( A carboxyl group-containing urethane resin obtained by a polyaddition reaction of (meth)acrylate or a partial acid anhydride modified product thereof, a carboxyl group-containing dialcohol compound and a diol compound.

(5) During the synthesis of the resin of (2) or (4), a compound having one hydroxyl group and one or more (meth)acryloyl group in a molecule such as hydroxyalkyl (meth)acrylate is added, and a terminal ( (Meth) Acrylic carboxyl group-containing urethane resin.

(6) During the synthesis of the resin of (2) or (4), one isocyanate group and one or more (meth)acryloyl group are introduced in the molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate. A carboxyl group-containing urethane resin in which the compound having the above is added and the terminal (meth)acrylated.

(7) Carboxyl group obtained by reacting a polyfunctional epoxy resin with (meth)acrylic acid and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to a hydroxyl group existing in a side chain. Containing resin.

(8) Carboxyl group-containing resin obtained by reacting a polyfunctional epoxy resin obtained by further epoxidizing a hydroxyl group of a bifunctional epoxy resin with epichlorohydrin with (meth)acrylic acid and adding a dibasic acid anhydride to the generated hydroxyl group. ..

(9) A carboxyl group-containing polyester resin obtained by reacting a polyfunctional oxetane resin with a dicarboxylic acid and adding a dibasic acid anhydride to the resulting primary hydroxyl group.

(10) Reaction product obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide with an unsaturated group-containing monocarboxylic acid A carboxyl group-containing resin obtained by reacting a product with a polybasic acid anhydride.

(11) Obtained by reacting an unsaturated group-containing monocarboxylic acid with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate and propylene carbonate. A carboxyl group-containing resin obtained by reacting a reaction product with a polybasic acid anhydride.

(12) An epoxy compound having a plurality of epoxy groups in one molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, such as p-hydroxyphenethyl alcohol, (meth) By reacting with an unsaturated group-containing monocarboxylic acid such as acrylic acid, with respect to the alcoholic hydroxyl group of the reaction product obtained, maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, anhydrous A carboxyl group-containing resin obtained by reacting a polybasic acid anhydride such as adipic acid.

(13) In addition to the carboxyl group-containing resin described in (1) to (12) above, one epoxy group and one or more (in addition to one or more (in the molecule of glycidyl (meth)acrylate, α-methylglycidyl (meth)acrylate) A carboxyl group-containing resin obtained by adding a compound having a (meth)acryloyl group.

Among the above-mentioned carboxyl group-containing resins, the carboxyl group-containing resins described in (1), (7), (8), (10) to (13) are preferable.

Examples of the compound having a phenolic hydroxyl group include compounds having a biphenyl skeleton, a phenylene skeleton, or both skeletons, phenol, orthocresol, paracresol, metacresol, 2,3-xylenol, 2,4-xylenol, and 2 ,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, catechol, resorcinol, hydroquinone, methylhydroquinone, 2,6-dimethylhydroquinone, trimethylhydroquinone, pyrogallol, phloroglucinol, etc. Examples thereof include phenol resins having various skeletons synthesized.

Examples of the compound having a phenolic hydroxyl group include phenol novolac resin, alkylphenol volac resin, bisphenol A novolac resin, dicyclopentadiene type phenol resin, Xylok type phenol resin, terpene modified phenol resin, polyvinylphenol, and bisphenol F. , Bisphenol S type phenol resin, poly-p-hydroxystyrene, condensate of naphthol and aldehyde, condensate of dihydroxynaphthalene and aldehyde, and the like, which are known and commonly used.

Examples of commercially available phenolic resins include HF1H60 (manufactured by Meiwa Kasei Co., Ltd.), Phenolite TD-2090, Phenolite TD-2131 (manufactured by Dai Nippon Printing Co., Ltd.), Besmol CZ-256-A (manufactured by DIC), and Show. Nord BRG-555, Shownor BRG-556 (manufactured by Showa Denko KK), CGR-951 (manufactured by Maruzen Oil Co., Ltd.), polyvinylphenol CST70, CST90, S-1P, S-2P (manufactured by Maruzen Oil Co., Ltd.). ..

The acid value of the alkali-soluble resin is preferably in the range of 20 to 200 mgKOH/g, more preferably 40 to 150 mgKOH/g. When the acid value of the (A) alkali-soluble resin is 20 mgKOH/g or more, the adhesion of the coating film is good and the alkali development is good. On the other hand, when the acid value is 200 mgKOH/g or less, the dissolution of the exposed area by the developer can be suppressed, so that the line becomes thinner than necessary, and in some cases, the exposed area and the unexposed area are not distinguished by dissolution in the developer. The resist pattern can be satisfactorily drawn by suppressing this.

The weight average molecular weight of the alkali-soluble resin varies depending on the resin skeleton, but is preferably in the range of 1,500 to 50,000, more preferably 1,500 to 30,000. When the weight average molecular weight is 1,500 or more, the tack-free performance is good, the moisture resistance of the coating film after exposure is good, the film loss during development can be suppressed, and the deterioration of resolution can be suppressed. On the other hand, when the weight average molecular weight is 50,000 or less, the developability is good and the storage stability is excellent.

The alkali-soluble resin may be used alone or in combination of two or more. The compounding ratio of the alkali-soluble resin is, for example, 0 to 55% by mass, and preferably 0 to 50% by mass, in the solid content excluding the solvent of the entire composition.

As the thermosetting component (A2), one type may be used alone, or two or more types may be used in combination. The blending ratio of the thermosetting component (A2) is, for example, 0 to 55% by mass, and preferably 0 to 50% by mass, in the solid content of the entire composition excluding the solvent.

[(B) Inorganic Filler ((B-1) Inorganic Filler and (B-2) Inorganic Filler)]
The curable composition of the present invention contains (B-1) an inorganic filler and (B-1) an inorganic filler having an average particle diameter different from that of the inorganic filler (B-2). The average particle diameter is 5 times or more the average particle diameter of the (B-2) inorganic filler, and the total of the solid content of the composition is the total of the (B-1) inorganic filler and the (B-2) inorganic filler. Contains 45 mass% or more of the mass. When the curable composition of the present invention contains (B-1) the inorganic filler and (B-2) the inorganic filler in a total amount of 50% by mass or more and 60% by mass or more of the total mass of the solid content of the composition. It is more effective, and is effective at 70% by mass or more, 80% by mass or more, and particularly 83% by mass or more.
Here, in the present specification, the average particle diameter of the inorganic fillers (B-1) and (B-2) includes not only the particle diameter of the primary particles but also the average particle diameter of the secondary particles (aggregates). It is a particle diameter (D50). The average particle diameters of the inorganic fillers (B-1) and (B-2) are D50 values measured by a laser diffraction method. As a measuring device by the laser diffraction method, Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd. can be mentioned. The maximum particle diameter (D100) and the particle diameter (D10) of the inorganic fillers (B-1) and (B-2) can be measured in the same manner with the above apparatus.

As described above, according to the present invention, by filling the gap of the (B-2) inorganic filler in the gap of the (B-1) inorganic filler, the remaining gap can be reduced and the resin content is small, that is, A curable resin composition having a high mass ratio of the filler in the mass is obtained. Even within the same product as a normal commercial product, there is originally a 2-3 times variation in particle size, but at that ratio, since fine particles do not effectively enter the gap, (B-1), (B- 2) A difference of 5 times or more is required for the average particle size of both fillers. The larger the average particle diameter ratio of the fillers (B-1) and (B-2), the better. It is more preferably 8 times or more, still more preferably 10 times or more.

The average particle size of the inorganic filler (B-1) is preferably 5 μm or less. (B-1) The average particle diameter of the inorganic filler varies depending on the use of the curable composition, and is preferably 5 μm or less for use in forming a cured film on an IC package substrate, for example, and cured on a printed wiring board for a mother board. The thickness is preferably 30 μm or less for use in forming a film, and 40 μm or less for molding (sealing). The maximum particle size of the inorganic filler (B-2) is preferably 500 nm or less. Furthermore, the particle diameter (D10) of the inorganic filler (B-1) is preferably 5 times or more the average particle diameter (D50) of the inorganic filler (B-2). When this ratio is 5 times or more, the filling efficiency of the (B-2) inorganic filler into the gap of the (B-1) inorganic filler is improved, and the balance between the strength of the cured product and the laminating property of the dry film is excellent. ..

The blending ratio of both inorganic fillers (B-1) and (B-2) is preferably (B-1):(B-2)=5:5 to 9:1 by volume ratio, and 6:4. It is more preferable that it is ˜8:2. Within the above range, both the strength of the cured product and the laminating property of the dry film can be further improved.

Materials of the inorganic fillers (B-1) and (B-2) are not particularly limited, and examples thereof include silica, barium sulfate, barium titanate, Neuburg silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, and oxidation. Examples thereof include titanium, aluminum hydroxide, silicon nitride, aluminum nitride and the like. Among them, silica is preferable, and it suppresses the curing shrinkage of the cured product of the curable composition, has a lower CTE, and improves properties such as adhesion and hardness. Examples of silica include fused silica, spherical silica, amorphous silica, and crystalline silica.

The presence or absence of surface treatment of the inorganic fillers (B-1) and (B-2) is not particularly limited. However, as described above, since the curable composition of the present invention has a low resin content, the (B-1) and (B-2) inorganic fillers may be surface-treated to improve dispersibility. preferable.

The surface treatment method of the inorganic fillers (B-1) and (B-2) is not particularly limited, and a known and commonly used method may be used. A surface treatment agent having a curable reactive group, for example, a curable reactive group. It suffices to treat the surface of the filler with a coupling agent or the like having the as an organic group.

The surface treatment of the inorganic fillers (B-1) and (B-2) is preferably a surface treatment with a coupling agent. As the coupling agent, silane-based, titanate-based, aluminate-based and zircoaluminate-based coupling agents can be used. Of these, silane coupling agents are preferred. Examples of such silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, N-(2-aminomethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-amino. Propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxy) Examples thereof include cyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane. These can be used alone or in combination. These silane coupling agents are preferably immobilized on the surface of the filler in advance by adsorption or reaction. Here, the treatment amount of the coupling agent with respect to 100 parts by mass of the filler is preferably 0.5 to 10 parts by mass. In the present invention, the coupling agent applied to the filler is not included in the compound having an ethylenically unsaturated group.

Examples of the photocurable reactive group include ethylenically unsaturated groups such as vinyl group, styryl group, methacryl group and acryl group. Among them, at least one of vinyl group and (meth)acrylic group is preferable.

As the thermosetting reactive group, hydroxyl group, carboxyl group, isocyanate group, amino group, imino group, epoxy group, oxetanyl group, mercapto group, methoxymethyl group, methoxyethyl group, ethoxymethyl group, ethoxyethyl group, oxazoline group, etc. Is mentioned. Of these, at least one of an amino group and an epoxy group is preferable.

In addition, the surface-treated inorganic fillers (B-1) and (B-2) may be contained in the curable composition of the present invention in a surface-treated state, and surface-untreated. The inorganic filler may be surface-treated in the composition by separately blending the inorganic filler and the surface treatment agent, but it is preferable to blend the inorganic filler which has been surface-treated in advance. By blending the inorganic fillers that have been surface-treated in advance, it is possible to prevent a decrease in crack resistance and the like due to the surface-treating agent that has not been consumed in the surface treatment that may remain when blended separately. In the case of surface treatment in advance, it is preferable to blend a preliminary dispersion liquid in which an inorganic filler is pre-dispersed in a solvent or a curable component, the surface-treated inorganic filler is pre-dispersed in a solvent, and the preliminary dispersion liquid is blended in the composition. It is more preferable to add the preliminary dispersion liquid to the composition after the surface treatment is sufficiently performed when the surface-untreated inorganic filler is predispersed in the solvent.
The inorganic fillers (B-1) and (B-2) may be blended with the component (A) or the like in a powder or solid state depending on the use mode of the curable composition of the present invention, and may be mixed with a solvent or a dispersant. You may mix with the component (A) etc. after mixing and making it into a slurry.

[UV absorber]
In the curable composition of the present invention, when the (A) curable component contains at least (A1) a photocurable component and a photopolymerization initiator, (B-1) an inorganic filler and (B-2). The higher the blending ratio of the inorganic filler, the more difficult it is to form the opening. However, even if the blending ratio of the (B-1) inorganic filler and the (B-2) inorganic filler is high, the UV absorber is further contained. The opening can be easily formed. From the viewpoint of resolution, the upper limit of the blending ratio of the (B-1) inorganic filler and the (B-2) inorganic filler is preferably 90% by mass or less, and 88% by mass or less. More preferable.
The ultraviolet absorber according to the present invention may be any one as long as it absorbs light having a wavelength of 300 nm to 450 nm.

Examples of the ultraviolet absorber include inorganic ultraviolet absorbers such as carbon black and black titanium oxide (also called titanium black), organic ultraviolet absorbers and the like. Among these, carbon black is most preferable from the viewpoint of the resolution of the cured product.

Examples of the organic ultraviolet absorber include a benzophenone derivative, a benzoate derivative, a benzotriazole derivative, a triazine derivative, a benzothiazole derivative, a cinnamate derivative, an anthranilate derivative, and a dibenzoylmethane derivative. Specific examples of the benzophenone derivative include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone and 2,4-dihydroxybenzophenone. Is mentioned. Specific examples of the benzoate derivative include 2-ethylhexyl salicylate, phenyl salicylate, p-t-butylphenyl salicylate, and 2,4-di-t-butylphenyl-3,5-di-t. -Butyl-4-hydroxybenzoate and hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate. Specific examples of the benzotriazole derivative include 2-(2'-hydroxy-5'-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole and 2 -(2'-Hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5 -Chlorobenzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole and the like can be mentioned. Specific examples of the triazine derivative include hydroxyphenyl triazine and bisethylhexyloxyphenol methoxyphenyl triazine.

The ultraviolet absorber may be a commercially available one, for example, TINUVIN PS, TINUVIN 99-2, TINUVIN 109, TINUVIN 384-2, TINUVIN 900, TINUVIN 928, TINUVIN 1130, TINUVIN 400, TINUVIN 405, TINUVIN 460, TINUVIN 479 (above, BASF Japan Ltd. make, brand name) etc. are mentioned.

The above-mentioned organic ultraviolet absorber is preferably used in combination with carbon black. When used in combination with carbon black, the resolution becomes more stable.

The ultraviolet absorbers may be used alone or in combination of two or more. The ultraviolet absorber is effective even in a small amount, and is preferably contained in an amount of 0.01 to 10% by mass based on the total mass of the solid content of the composition. From the viewpoint of deep curability that affects the resolution of the cured product, 0 0.02 to 7 mass% is more preferable. When carbon black is contained as the ultraviolet absorber, it is preferably contained in an amount of 0.01 to 1% by mass based on the total mass of the solid content of the composition, from the viewpoint of the resolution of the cured product. It is more preferable to contain 0.02 to 0.5 mass% of the total mass of, and it is particularly preferable to contain 0.05 to 0.30 mass% of the total mass of the solid content of the composition.

(Organic solvent)
The curable composition of the present invention may contain an organic solvent for the purpose of preparing the composition and adjusting the viscosity when applied to a substrate or a carrier film. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether. , Glycol ethers such as dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, tripropylene glycol monomethyl ether; ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbyl Esters such as tall acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, solvent naphtha, etc. Conventional organic solvents can be used. These organic solvents may be used alone or in combination of two or more.

(Other optional ingredients)
If necessary, the curable composition of the present invention further comprises a photoinitiator aid, a cyanate compound, an elastomer, a mercapto compound, a thermosetting catalyst, a urethanization catalyst, a thixotropic agent, an adhesion promoter, a block copolymer, Chain transfer agents, polymerization inhibitors, copper damage inhibitors, antioxidants, rust inhibitors, UV absorbers, thickeners such as finely divided silica, organic bentonite, montmorillonite, etc., silicone-based, fluorine-based, polymer-based, etc. Ingredients such as foaming agents and/or leveling agents, imidazole-based, thiazole-based, triazole-based silane coupling agents, phosphinates, phosphate ester derivatives, flame retardants such as phosphorus compounds such as phosphazene compounds, and colorants be able to. As these, those known in the field of electronic materials can be used.

The curable composition of the present invention may be used as a dry film or used as a liquid. When it is used as a liquid, it may be one-part or two-part or more.

INDUSTRIAL APPLICABILITY The curable composition of the present invention is useful for forming a pattern layer as a permanent coating of a printed wiring board such as a solder resist, a coverlay and an interlayer insulating layer, and particularly useful for forming a solder resist. Further, since the curable composition of the present invention can form a cured product having excellent coating film strength even in a thin film, a printed wiring board required to be thin, for example, an IC package board (printed wiring board used for an IC package). It can also be suitably used for forming a pattern layer in. Furthermore, the cured product obtained from the curable composition of the present invention is suitable for forming a pattern layer in an IC package substrate having a thin total thickness and a lack of rigidity, in terms of high elastic modulus and low CTE. You can say that you can.

The curable composition of the present invention can be in the form of a dry film provided with a carrier film (support) and a resin layer formed on the carrier film and comprising the curable composition. In forming a dry film, the curable composition of the present invention is diluted with the organic solvent to have an appropriate viscosity, and a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, a reverse coater, a transfer roll coater, A film can be obtained by coating the carrier film with a uniform thickness using a gravure coater, a spray coater or the like, and usually drying at a temperature of 50 to 130° C. for 1 to 30 minutes. The coating film thickness is not particularly limited, but in general, the film thickness after drying is appropriately selected within the range of 1 to 150 μm, preferably 10 to 60 μm.

As the carrier film, a plastic film is used, and it is preferable to use a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film or the like. The thickness of the carrier film is not particularly limited, but generally, it is appropriately selected within the range of 10 to 150 μm.

After forming the curable composition of the present invention on a carrier film, it is preferable to further laminate a peelable cover film on the surface of the film for the purpose of preventing dust from adhering to the surface of the film. .. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used, and the peeling force is more than the adhesive force between the membrane and the carrier film when peeling the cover film. The adhesive force between the membrane and the cover film may be smaller.

In the present invention, the curable composition of the present invention may be applied onto the cover film and dried to form a resin layer, and a carrier film may be laminated on the surface of the resin layer. That is, as the film to which the curable composition of the present invention is applied when the dry film is produced in the present invention, either a carrier film or a cover film may be used.

The printed wiring board of the present invention has a curable composition of the present invention or a cured product obtained from a resin layer of a dry film. Examples of the method for producing a printed wiring board of the present invention include adjusting the curable composition of the present invention to a viscosity suitable for a coating method using the above organic solvent, dip coating method on a substrate, and flow. After applying by a coating method, a roll coating method, a bar coater method, a screen printing method, a curtain coating method or the like, the organic solvent contained in the composition is volatilized and dried (temporary drying) at a temperature of 60 to 100°C. Then, a tack-free resin layer is formed. In the case of a dry film, the resin layer is formed on the base material by adhering the resin layer on the base material with a laminator or the like so that the resin layer contacts the base material, and then peeling off the carrier film.

As the above-mentioned base material, in addition to a printed wiring board or a flexible printed wiring board on which a circuit is previously formed of copper, paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth/non-woven cloth epoxy, glass cloth/paper epoxy. , Synthetic fiber epoxy, fluororesin/polyethylene/polyphenylene ether, polyphenylene oxide/cyanate, etc. are used for copper clad laminates for high frequency circuits. Copper clad laminates of all grades (FR-4 etc.) Plates and the like, metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates and the like can be mentioned.

Volatile drying performed after applying the curable composition of the present invention, hot air circulation type drying furnace, IR furnace, hot plate, convection oven and the like (using a hot air in the dryer using a heat source of air heating system by steam In a countercurrent manner and a method of spraying onto a support from a nozzle).

After forming a resin layer on a printed wiring board, it is selectively exposed to an active energy ray through a photomask having a predetermined pattern, and the unexposed portion is diluted with a dilute alkaline aqueous solution (for example, a 0.3 to 3 mass% sodium carbonate aqueous solution). ) To form a cured product pattern. Further, the cured product is irradiated with an active energy ray and then heat-cured (for example, 100 to 220° C.), or after the heat-cured material is irradiated with an active energy ray, or is subjected to final finish curing (main curing) only by heat-curing, thereby achieving close contact. A cured film having excellent properties such as properties and hardness is formed.

The exposure machine used for irradiation with the active energy rays may be a high-pressure mercury lamp lamp, an ultra-high pressure mercury lamp lamp, a metal halide lamp, a mercury short arc lamp, or any other apparatus that irradiates ultraviolet rays in the range of 350 to 450 nm. Furthermore, a direct drawing device (for example, a laser direct imaging device that draws an image directly with a laser using CAD data from a computer) can also be used. A lamp light source or a laser light source for a direct drawing machine may have a maximum wavelength in the range of 350 to 450 nm. The exposure amount for image formation varies depending on the film thickness and the like, but it can be generally in the range of 10 to 1000 mJ/cm ² , and preferably 20 to 800 mJ/cm ² .

The developing method may be a dipping method, a shower method, a spray method, a brush method, or the like, and the developing solution may be potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, Aqueous alkaline solutions such as ammonia and amines can be used.
The curable composition of the present invention may be used not only for forming a pattern of a cured film with a developer as described above, but also for not forming a pattern, for example, for molding (sealing).

The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following, "part" and "%" are based on mass unless otherwise specified.

(Synthesis of alkali-soluble resin)
In an autoclave equipped with a thermometer, a nitrogen introducing device and an alkylene oxide introducing device, and a stirrer, 119.4 parts of a novolac type cresol resin (trade name "SHOUNOL CRG951", Showa Denko KK, OH equivalent: 119.4), 1.19 parts of potassium hydroxide and 119.4 parts of toluene were introduced, the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 parts of propylene oxide was gradually added dropwise and reacted at 125 to 132° C. and 0 to 4.8 kg/cm ² for 16 hours. After that, the mixture was cooled to room temperature, and 1.56 parts of 89% phosphoric acid was added to and mixed with this reaction solution to neutralize potassium hydroxide, with a nonvolatile content of 62.1% and a hydroxyl value of 182.2 mgKOH/g (307. A propylene oxide reaction solution of a novolac type cresol resin having a concentration of 9 g/eq.) was obtained. This was an average of 1.08 mol of propylene oxide added per equivalent of the phenolic hydroxyl group.
The obtained propylene oxide reaction solution of novolac type cresol resin 293.0 parts, acrylic acid 43.2 parts, methanesulfonic acid 11.53 parts, methylhydroquinone 0.18 parts and toluene 252.9 parts were stirred with a stirrer and a temperature. It was introduced into a reactor equipped with a meter and an air blowing tube, air was blown at a rate of 10 ml/min, and the reaction was carried out at 110° C. for 12 hours while stirring. The water produced by the reaction was an azeotropic mixture with toluene, and 12.6 parts of water was distilled out. Then, it was cooled to room temperature, the resulting reaction solution was neutralized with 35.35 parts of a 15% sodium hydroxide aqueous solution, and then washed with water. Then, toluene was distilled off while substituting 118.1 parts of diethylene glycol monoethyl ether acetate with an evaporator to obtain a novolac type acrylate resin solution. Next, 332.5 parts of the resulting novolac type acrylate resin solution and 1.22 parts of triphenylphosphine were introduced into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was supplied at a rate of 10 ml/min. Was blown in, and 60.8 parts of tetrahydrophthalic anhydride was gradually added with stirring, and the mixture was reacted at 95 to 101° C. for 6 hours, cooled, and taken out. Thus, a solution of the photosensitive carboxyl group-containing resin A-1 having a solid content of 65% and a solid content of an acid value of 87.7 mgKOH/g was obtained. Hereinafter, the solution of the carboxyl group-containing photosensitive resin is referred to as a resin solution A-1.

((B-1) Preparation of Inorganic Filler 1)
A dispersion treatment was performed using 700 g of spherical silica (Admafine SO-E2) manufactured by Admatech, 300 g of PMA (propylene glycol monomethyl ether acetate) as a solvent, and 0.5 μm zirconia beads in a bead mill. This was repeated 3 times and filtered through a 3 μm filter to prepare a silica slurry having an average particle size of 500 nm. In addition, this (B-1) inorganic filler 1 has a particle diameter D10 of 250 nm and a maximum particle diameter D100 of 3 μm.

((B-1) Preparation of inorganic filler 2)
700 g of spherical silica (Admafine SO-E1) manufactured by Admatech, 300 g of PMA (propylene glycol monomethyl ether acetate) as a solvent, and 0.5 μm zirconia beads were dispersed in a bead mill for dispersion treatment. This was repeated 3 times and filtered through a 3 μm filter to prepare a silica slurry having an average particle size of 250 nm. In addition, this (B-1) inorganic filler 2 has a particle diameter D10 of 100 nm and a maximum particle diameter D100 of 1 μm.

((B-2) Preparation of inorganic filler)
A silica slurry having a vinyl group-containing average particle diameter of 50 nm (YA050C, PMA (propylene glycol monomethyl ether acetate) solvent) manufactured by Admatech was used. In addition, this (B-2) inorganic filler has a particle diameter D10 of 20 nm and a maximum particle diameter D100 of 0.2 μm.

(Examples 1 to 11 and Comparative Examples 1 to 3)
The curable composition was prepared by blending together various components shown in the table below in the proportions (parts by mass) shown in the table, premixing with a stirrer, and kneading with a bead mill. Each of the obtained curable compositions was applied onto a 38 μm polyester film using an applicator and dried at 80° C. for 20 minutes to prepare a dry film having a resin layer with a thickness of 20 μm.

(Lamination property)
Copper thickness 15 μm, L (line: wiring width)/S (space: space width) is 1.0 μm equivalent as a pretreatment for a double-sided printed wiring board having the following comb-teeth pattern by CZ-8101 manufactured by Mech Co. An etching process was performed. Then, the dry films of Examples and Comparative Examples were laminated using a vacuum laminator (CVP-300: manufactured by Nikko Material Co., Ltd.) in a first chamber at 80° C. under a vacuum pressure of 3 hPa and a vacuum time of 30 seconds. Then, pressing was performed under the conditions of a pressing pressure of 0.5 MPa and a pressing time of 30 seconds to obtain an evaluation substrate. It was observed with a scanning electron microscope (SEM, magnification 1000 times) whether or not the resin layer of the dry film was in contact with the bottom surface (surface of the substrate) of the space of the evaluation substrate after lamination.
⊚: When L/S=10/10, the resin layer of the dry film was in contact with the bottom surface of the space (the surface of the substrate).
◯: When L/S=20/20, the resin layer of the dry film was in contact with the bottom surface of the space.
Δ: When L/S=50/50, the resin layer of the dry film was in contact with the bottom surface of the space.
X: When L/S=50/50, the resin layer of the dry film was not in contact with the bottom surface of the space.

(Storage elastic modulus)
GTS-MP foil (manufactured by Furukawa Circuit Foil Co., Ltd.) was placed on the shiny side (copper foil), and each of the dry films according to Examples and Comparative Examples produced above was placed so that the resin layer was in contact with the copper foil. By laminating with a vacuum laminator in the same manner as above, a resin layer was formed on the copper foil and the carrier film was peeled off. This was irradiated with ultraviolet rays in a UV conveyor furnace under conditions of an integrated exposure amount of 1000 mJ/cm ² and then heated at 170° C. for 60 minutes to be cured. After that, the cured film was peeled off from the copper foil, and then a sample was cut into a measurement size (size of 5 mm×50 mm×20 μm (length×width×thickness)). The sample was subjected to DMS6100 (manufactured by Hitachi High-Tech Science Co., Ltd.) and the storage elastic modulus at 25° C. was measured at a frequency of 1 Hz.
Good: Storage elastic modulus at 25° C. is 10 GPa or more.
X: Storage elastic modulus at 25° C. is less than 10 GPa.

(Coefficient of linear expansion (CTE))
GTS-MP foil (manufactured by Furukawa Circuit Foil Co., Ltd.) was placed on the shiny side (copper foil), and the dry films according to the examples and comparative examples prepared above were placed so that the resin layer was in contact with the copper foil. By laminating with a vacuum laminator in the same manner as above, a resin layer was formed on the copper foil and the carrier film was peeled off. This was irradiated with ultraviolet rays in a UV conveyor furnace under conditions of an integrated exposure amount of 1000 mJ/cm ² and then heated at 170° C. for 60 minutes to be cured. Then, after peeling the cured film from the copper foil, a sample was cut into a measurement size (size of 5 mm×50 mm×20 μm (length×width×thickness)) and provided for TMA6100 manufactured by Seiko Instruments Inc. In the TMA measurement, the test load was 5 g, and the sample was heated from room temperature at a temperature rising rate of 10° C./min and continuously measured twice. The glass transition temperature (Tg) was defined as the intersection of two tangents having different linear expansion coefficients in the second time, and the coefficient of linear expansion (CTE(α1)) in the region of Tg or less was evaluated. The judgment criteria are as follows.
◯: CTE at Tg temperature or lower is 20 ppm or lower.
X: CTE at Tg temperature or lower is over 20 ppm.

(Resolution)
Each curable composition of each of Examples 7 to 11 was applied on the entire surface of a copper foil and dried at 80°C for 30 minutes, and a direct imaging exposure device (a light source was used so that the exposure amount on the composition was 50 mJ/cm ^{2 ).} It was irradiated with light from a high pressure mercury lamp) and developed with a 1% sodium carbonate aqueous solution at 30° C. to form a pattern of a cured product. After the pattern formation, it was evaluated whether an opening diameter of 80 μm could be formed and the shape was good.
A: An opening can be formed, and the wall surface of the opening has a straight shape.
◯: An opening can be formed.
X: An opening cannot be formed.

＊１：上記で合成したアルカリ可溶性樹脂の溶液Ａ−１
＊２：ＩＧＭ社製ＯｍｎｉｒａｄＴＰＯ（２，４，６−トリメチルベンゾイル−ジフェニル−フォスフィンオキサイド）（光重合開始剤）
＊３：ＤＩＣ社製エピクロンＮ−８７０（ビスフェノールＡノボラック型エポキシ樹脂）＊４：ＢＡＳＦ社製Ｌａｒｏｍｅｒ（エチレン性不飽和基を有する化合物）
＊５：上記で調製した（Ｂ−１）無機フィラー１
＊６：上記で調製した（Ｂ−１）無機フィラー２
＊７：上記で調製した（Ｂ−２）無機フィラー
＊８：三菱化学社製ＭＡ−１００
＊９：三菱マテリアル社製１３Ｍ−Ｃ
＊１０：ＢＡＳＦ社製ＴＩＮＵＶＩＮ４６０

*1: Solution A-1 of the alkali-soluble resin synthesized above
*2: OmniradTPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide) manufactured by IGM (photopolymerization initiator)
*3: Epicron N-870 (bisphenol A novolac type epoxy resin) manufactured by DIC *4: Laromer (compound having an ethylenically unsaturated group) manufactured by BASF
*5: (B-1) inorganic filler 1 prepared above
*6: (B-1) inorganic filler 2 prepared above
*7: (B-2) inorganic filler prepared above *8: Mitsubishi Chemical's MA-100
*9: Mitsubishi Materials 13M-C
*10: TINUVIN460 manufactured by BASF

From the results shown in the above table, it is possible to obtain a curable composition having a high mass ratio of the filler in the total mass of the solid content by using two kinds of fillers having different average particle diameters of 5 times or more. Recognize. Further, from the results shown in the above table, it can be seen that even in the case of the resin composition having a high filler mass ratio, the dry film has excellent laminating properties.
Furthermore, when the curable composition of the present invention thus obtained is used, the strength of the cured product is excellent, the storage elastic modulus is high, the coefficient of linear expansion (CTE) is low, and the laminating property of the dry film is excellent. I understand.
Further, it is found that carbon black is most preferable as the ultraviolet absorber from the viewpoint of resolution of the cured product.

Claims (8)

A curable composition containing a curable component (A), an inorganic filler (B-1), and an inorganic filler (B-2) having a different average particle diameter from the inorganic filler (B-1),
The curable component (A) includes a carboxyl group-containing resin, a compound having an ethylenically unsaturated group different from the carboxyl group-containing resin, and a compound having a plurality of cyclic ether groups or cyclic thioether groups in the molecule. ,
Further, including a photopolymerization initiator as a photo radical generator ,
The carboxyl group-containing resin,
A carboxyl group-containing resin obtained by reacting a polyfunctional epoxy resin with (meth)acrylic acid to add a dibasic acid anhydride to a hydroxyl group present in a side chain, and
A reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide is reacted with an unsaturated group-containing monocarboxylic acid, and the obtained reaction product is reacted with a polybasic acid anhydride. Containing any one or more of the carboxyl group-containing resin obtained by
The average particle size of the (B-1) inorganic filler is 5 times or more the average particle size of the (B-2) inorganic filler,
The inorganic filler (B-1) and the inorganic filler (B-2) are contained in a total amount of 45% by mass or more of the total solid content of the composition,
The average particle size of the (B-1) inorganic filler is 5 μm or less,
The curable composition, wherein the maximum particle diameter of the inorganic filler (B-2) is 500 nm or less. The curable composition according to claim 1, wherein the average particle diameter of the (B-1) inorganic filler is 8 times or more the average particle diameter of the (B-2) inorganic filler. The curing according to claim 1 or 2, wherein the total amount of the (B-1) inorganic filler and the (B-2) inorganic filler is 80% by mass or more of the total mass of the solid content of the composition. Sex composition. The curable composition according to any one of claims 1 to 3, further comprising an ultraviolet absorber. The curable composition according to claim 4, wherein the ultraviolet absorber is carbon black. A dry film having a resin layer obtained from the curable composition according to claim 1. A cured product obtained by curing the curable composition according to claim 1 or the resin layer of the dry film according to claim 6. A printed wiring board comprising the cured product according to claim 7.