JP7187227B2 - Curable resin composition, dry film, cured product and printed wiring board - Google Patents

Description

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

As a method for manufacturing a printed wiring board, an interlayer insulating layer made of a thermosetting resin composition is formed on a circuit-formed substrate, openings for via holes are provided in this interlayer insulating layer by a carbon dioxide gas laser or the like, and plating is performed. Methods of forming conductive circuits including via holes are widely known.
In the manufacturing method of such a printed wiring board, as electronic devices become more sophisticated and smaller and lighter in weight in recent years, the density of conductor circuits also advances, and it is necessary to form openings for via holes with smaller diameters in interlayer insulating layers. was there. However, with conventional carbon dioxide laser processing, it is difficult to form openings with a diameter of 40 μm or less. On the other hand, UV laser processing, which can form smaller diameter openings, is also conceivable. .

On the other hand, conventionally, a method has been proposed in which a photolithography technique using a photosensitive curable resin composition is applied to formation of openings for via holes in interlayer insulating layers (see, for example, Patent Documents 1 and 2).

On the other hand, in the method of manufacturing a printed wiring board, a conductor circuit formed on an interlayer insulating layer is required to have excellent adhesion to the interlayer insulating layer, that is, so-called peel strength. Therefore, the surface of the interlayer insulating layer and the side surface of the via hole opening are roughened with a roughening agent such as sodium hydroxide, potassium permanganate, and sulfuric acid, and then electroless copper plating and electrolytic copper plating are applied. A method of forming a conductive circuit by plating in order is widely adopted (see, for example, Patent Document 2).

However, in such a method of forming a conductor circuit, there is a problem that the contact area between the interlayer insulating layer and the circuit conductor increases due to the surface roughening treatment, which causes transmission loss and insulation deterioration.

In particular, in the method for forming such a conductive circuit and the method for manufacturing the printed wiring board described in Cited Document 2 using the photolithography technique described above, after the surface roughening treatment, the surface and side surfaces of the via hole opening (via portion) are The inventors have found that there is a new problem of cracking. When such cracks occur, the insulation reliability between adjacent via holes cannot be obtained, and the contact area between the circuit conductor and the interlayer insulating layer increases, resulting in an increase in transmission loss. It should be noted that such cracks after the surface-roughening treatment were a problem that did not occur in the interlayer insulating layer formed using the thermosetting resin composition.

On the other hand, recent via hole openings are required not only to have a small diameter, but also to have a high resolution in which the ratio of the top diameter to the bottom diameter of the opening (bottom diameter/top diameter) is substantially 1. However, it has been found that the technique described in Cited Document 1 has a problem that sufficient resolution cannot be obtained.

JP-A-10-142791 JP 2017-116652 A

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an interlayer insulating layer that has excellent resolution, is less prone to cracking in via hole openings after surface roughening, and has excellent adhesion to circuit conductors and excellent insulation reliability between circuits. To provide a photosensitive curable resin composition effective for forming

The inventors of the present invention have made intensive studies to achieve the above object. As a result, the above object is achieved by using an inorganic filler with a specific average particle size as the inorganic filler that is decomposed or dissolved by the roughening agent, and by using a spherical inorganic filler that is not decomposed or dissolved by the roughening agent. We have found that it is possible, and have completed the present invention.

That is, the curable resin composition of the present invention is decomposed or dissolved by (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) a thermosetting compound, and (D-1) a roughening agent. and (D-2) a spherical inorganic filler that is not decomposed or dissolved by a roughening agent.

In the curable resin composition of the present invention, the (D-2) spherical inorganic filler that is not decomposed or dissolved by the roughening agent is preferably silica and/or alumina.

In the curable resin composition of the present invention, the average particle size of the (D-2) spherical inorganic filler that is not decomposed or dissolved by the roughening agent is preferably 4 μm or less.

The dry film of the present invention is characterized by having a resin layer obtained from the curable resin composition.

The cured product of the present invention is obtained by curing the curable resin 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, an interlayer insulating layer having excellent resolution, less cracking in via hole openings after roughening treatment, excellent adhesion to circuit conductors, and excellent insulation reliability between circuits is provided. A photosensitive curable resin composition effective for forming can be provided.

The curable resin composition of the present invention comprises (A) an alkali-soluble resin, (B) a photopolymerization initiator, (C) a thermosetting compound, and (D-1) an average decomposed or dissolved by a roughening agent. An inorganic filler with a particle diameter of 0.5 to 6 μm (hereinafter also referred to as “(D-1) inorganic filler”), and (D-2) a spherical inorganic filler that is not decomposed or dissolved by a roughening agent (hereinafter, “ (D-2) (also referred to as "inorganic filler").

In the present invention, by using the inorganic fillers (D-1) and (D-2) in combination, cracks at the opening of the via hole can be suppressed. Although the detailed mechanism is not clear, even if a crack occurs due to the strain generated in the roughening treatment process, it is speculated that the spherical inorganic filler will fall off at the tip of the crack, suppressing the progress of the crack. be. Further, by setting the average particle size of the inorganic filler (D-1) to 0.5 to 6 μm, not only excellent resolution, but also a cured product excellent in adhesion and insulation with the copper plating layer can be formed.

Each component of the curable resin composition of the present invention will be described in detail below.

[(A) alkali-soluble resin]
The curable resin composition of the present invention contains (A) an alkali-soluble resin. As the alkali-soluble resin, any resin that contains at least one functional group selected from a phenolic hydroxyl group, a thiol group, a sulfonyl group and a carboxyl group and is soluble in an alkaline solution can be used, preferably. 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, a compound having two or more thiol groups, and a compound having a sulfo group can be used. In particular, as the alkali-soluble resin, a carboxyl group-containing resin is more preferable.
From the viewpoint of photocurability and development resistance, the carboxyl group-containing resin preferably has an ethylenically unsaturated group in the molecule in addition to the carboxyl group. A (meth)acryloyl group is preferred as the ethylenically unsaturated group. As used herein, (meth)acryloyl group is a generic term for acryloyl group, methacryloyl group and mixtures thereof, and the same applies to other similar expressions.

Carboxyl group-containing resins include, for example, compounds (both oligomers and polymers) 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, isobutylene, or the like.

(2) Diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates and aromatic diisocyanates; Carboxyl group-containing urethane resins obtained by polyaddition reaction of diol compounds such as polyols, polyester-based polyols, polyolefin-based polyols, acrylic polyols, bisphenol A-based alkylene oxide adduct diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

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

(4) Diisocyanate and 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 ( Photosensitive carboxyl group-containing urethane resin obtained by a polyaddition reaction of meth)acrylate or its partial acid anhydride modified product, a carboxyl group-containing dialcohol compound and a diol compound.

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

(6) During the synthesis of the resin of (2) or (4), one isocyanate group and one or more (meth)acryloyl groups in the molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate A carboxyl group-containing urethane resin that is terminally (meth)acrylated by adding a compound having

(7) Photosensitivity 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 the hydroxyl group present in the side chain. Carboxyl group-containing resin.

(8) A photosensitive carboxyl group obtained by reacting (meth)acrylic acid with a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl group of a bifunctional epoxy resin with epichlorohydrin, and adding a dibasic acid anhydride to the resulting hydroxyl group. Contained resin.

(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) 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 and reacting an unsaturated group-containing monocarboxylic acid to obtain a reaction product A carboxyl group-containing photosensitive resin obtained by reacting a polybasic acid anhydride with a substance.

(11) Obtained by reacting 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 or propylene carbonate with a monocarboxylic acid containing an unsaturated group. A carboxyl group-containing photosensitive 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; Maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic acid to the alcoholic hydroxyl group of the reaction product obtained by reacting with a monocarboxylic acid containing an unsaturated group such as acrylic acid. A carboxyl group-containing photosensitive resin obtained by reacting a polybasic acid anhydride such as an acid.

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

(14) A photosensitive carboxyl group-containing resin obtained by reacting a carboxyl group-containing (meth)acrylic copolymer resin with a compound having an oxirane ring and an ethylenically unsaturated group in one molecule.

(15) A compound having one epoxy group and an unsaturated double bond in each molecule and a copolymer of a compound having an unsaturated double bond are reacted with an unsaturated monocarboxylic acid to produce the second A photosensitive carboxyl group-containing resin obtained by reacting a secondary hydroxyl group with a saturated or unsaturated polybasic acid anhydride.

(16) After reacting a hydroxyl group-containing polymer with a saturated or unsaturated polybasic acid anhydride, the resulting carboxylic acid is reacted with a compound having one epoxy group and an unsaturated double bond in each molecule. a photosensitive hydroxyl group- and carboxyl group-containing resin obtained by

Since the carboxyl group-containing resin as described above has a large number of carboxyl groups in the side chains of the backbone polymer, development with an alkaline aqueous solution is possible.

Also, as the alkali-soluble resin, an alkali-soluble resin having at least one amideimide structure represented by the following formula (a) or (b) can be preferably used. By containing a resin having an imide bond directly bonded to a cyclohexane ring or a benzene ring, a cured product having more excellent toughness and heat resistance can be obtained. In particular, an amideimide resin having a structure represented by the following (a) is excellent in light transmittance, and thus can further improve the resolution of the resin composition. The alkali-soluble resin having at least one of the amideimide structures represented by the following formula (a) or (b) preferably has transparency. % or more.

The content of the structures represented by formulas (a) and (b) in the alkali-soluble resin having the amide-imide structure is preferably 10 to 70% by mass. By using such a resin, it is possible to obtain a cured product that is excellent in solvent solubility, heat resistance, physical properties such as tensile strength and elongation, and dimensional stability. It is preferably 10 to 60% by mass, more preferably 20 to 50% by mass.

（式（ａ１）および（ａ２）中、それぞれ、Ｒは１価の有機基であり、Ｈ、ＣＦ_３またはＣＨ_３であることが好ましく、Ｘは直接結合または２価の有機基であり、直接結合、ＣＨ_２またはＣ（ＣＨ_３）_２等のアルキレン基であることが好ましい。）で表される構造を有する樹脂が、引張強度や伸度等の物性および寸法安定性に優れるため好ましい。溶解性や機械物性の観点から、式（ａ）の構造を有するアミドイミド樹脂として、式（ａ１）および（ａ２）の構造を１０～１００質量％有する樹脂を好適に用いることができる。より好ましくは２０～８０質量％である。 As the alkali-soluble resin having an amide imide structure represented by formula (a), in particular, the following formula (a1) or (a2)

(in formulas (a1) and (a2), respectively, R is a monovalent organic group, preferably H, _CF3 or _CH3 ; X is a direct bond or a divalent organic group; and It is preferably a bond, or an alkylene group such as CH ₂ or C(CH ₃ ) ₂ .) is preferable because it has excellent physical properties such as tensile strength and elongation, and dimensional stability. From the viewpoint of solubility and mechanical properties, resins having 10 to 100 mass % of the structures of formulas (a1) and (a2) can be preferably used as the amideimide resin having the structure of formula (a). More preferably, it is 20 to 80% by mass.

Further, as the amideimide resin having the structure of the formula (a), an amideimide resin containing 5 to 100 mol% of the structures of the formulas (a1) and (a2) can be preferably used from the viewpoint of solubility and mechanical properties. . It is more preferably 5 to 98 mol %, still more preferably 10 to 98 mol %, particularly preferably 20 to 80 mol %.

（式（ｂ１）および（ｂ２）中、それぞれ、Ｒは１価の有機基であり、Ｈ、ＣＦ_３またはＣＨ_３であることが好ましく、Ｘは直接結合または２価の有機基であり、直接結合、ＣＨ_２またはＣ（ＣＨ_３）_２などのアルキレン基であることが好ましい。）で表される構造を有する樹脂が、引張強度や伸度等の機械的物性に優れる硬化物が得られることから好ましい。溶解性や機械物性の観点から、式（ｂ）の構造を有するアミドイミド樹脂として、式（ｂ１）および（ｂ２）の構造を１０～１００質量％有する樹脂を好適に用いることができる。より好ましくは２０～８０質量％である。 Further, as the alkali-soluble resin having an amide imide structure represented by formula (b), in particular, formula (b1) or (b2)

(in formulas (b1) and (b2), respectively, R is a monovalent organic group, preferably H, _CF3 or _CH3 ; X is a direct bond or a divalent organic group; and A bond, an alkylene group such as CH ₂ or C(CH ₃ ) ₂ is preferable.) A cured product having excellent mechanical properties such as tensile strength and elongation can be obtained. preferred from From the viewpoint of solubility and mechanical properties, resins having 10 to 100% by mass of the structures of formulas (b1) and (b2) can be suitably used as the amideimide resin having the structure of formula (b). More preferably, it is 20 to 80% by mass.

As the amideimide resin having the structure of formula (b), an amideimide resin containing 2 to 95 mol% of the structures of formulas (b1) and (b2) can also be preferably used for the reason of exhibiting good mechanical properties. More preferably 10 to 80 mol %.

An alkali-soluble resin having an amide-imide structure can be obtained by a known method. The amideimide resin having the structure of formula (a) can be obtained, for example, using a diisocyanate compound having a biphenyl skeleton and cyclohexanepolycarboxylic acid anhydride.

Diisocyanate compounds having a biphenyl skeleton include 4,4'-diisocyanate-3,3'-dimethyl-1,1'-biphenyl, 4,4'-diisocyanate-3,3'-diethyl-1,1'-biphenyl , 4,4′-diisocyanate-2,2′-dimethyl-1,1′-biphenyl, 4,4′-diisocyanate-2,2′-diethyl-1,1′-biphenyl, 4,4′-diisocyanate- 3,3'-ditrifluoromethyl-1,1'-biphenyl, 4,4'-diisocyanate-2,2'-ditrifluoromethyl-1,1'-biphenyl and the like. In addition, aromatic polyisocyanate compounds such as diphenylmethane diisocyanate may be used.

Cyclohexanepolycarboxylic anhydrides include cyclohexanetricarboxylic anhydride and cyclohexanetetracarboxylic anhydride.

Also, the amideimide resin having the structure of formula (b) can be obtained, for example, using the diisocyanate compound having the biphenyl skeleton and the polycarboxylic acid hydrate having two acid anhydride groups.

Examples of polycarboxylic acid waters having two acid anhydride groups include pyromellitic dianhydride, benzophenone-3,3′,4,4′-tetracarboxylic dianhydride, diphenyl ether-3,3′, 4,4'-tetracarboxylic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, biphenyl-3,3',4,4'-tetracarboxylic dianhydride, biphenyl- 2,2′,3,3′-tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 1,1 -bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,3-bis(3,4-dicarboxyphenyl)propane dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, bis(3,4-dicarboxyphenyl)ether di Anhydrides, alkylene glycol bis-anhydrotrimellitate such as ethylene glycol bis-anhydro-trimellitate, and the like.

Specific examples of the alkali-soluble resin having the amide imide structure include Unidic V-8000 series manufactured by DIC Corporation and SOXR-U manufactured by Nippon Kodoshi Co., Ltd.

The (A) alkali-soluble resin as described above may be used alone or in combination of two or more.
Such an alkali-soluble resin preferably has an acid value in the range of 20-120 mgKOH/g, more preferably in the range of 30-100 mgKOH/g. By setting the acid value of the alkali-soluble resin within the above range, good alkali development becomes possible, and a normal cured product pattern can be formed.
The weight-average molecular weight of such an alkali-soluble resin varies depending on the resin skeleton, but is generally from 1,500 to 150,000. When the weight average molecular weight is 1,500 or more, the tack-free properties of the dried coating film and the moisture resistance of the coating film after exposure are good, and the resolution is also better. On the other hand, when the weight average molecular weight is 150,000 or less, the developability and storage stability are good. More preferably 1,500 to 50,000.

(Compound having an ethylenically unsaturated group)
The curable resin composition of the present invention can contain a compound having an ethylenically unsaturated group in addition to the component (A). In this specification, when other components including the component (A) have an ethylenically unsaturated group, such components are excluded from the "compound having an ethylenically unsaturated group".

As the compound having an ethylenically unsaturated group, a known and commonly used photopolymerizable oligomer, photopolymerizable vinyl monomer, or the like can be used.
Examples of photopolymerizable oligomers include unsaturated polyester-based oligomers and (meth)acrylate-based oligomers. (Meth)acrylate oligomers include epoxy (meth)acrylates such as phenol novolac epoxy (meth)acrylate, cresol novolak epoxy (meth)acrylate, bisphenol type epoxy (meth)acrylate, urethane (meth)acrylate, epoxyurethane (meth)acrylate, ) acrylates, polyester (meth)acrylates, polyether (meth)acrylates, polybutadiene-modified (meth)acrylates, and the like.

Examples of photopolymerizable vinyl monomers include styrene derivatives such as styrene, chlorostyrene and α-methylstyrene; vinyl esters such as vinyl acetate, vinyl butyrate and vinyl benzoate; vinyl isobutyl ether, vinyl-n-butyl ether, vinyl -Vinyl ethers such as t-butyl ether, vinyl-n-amyl ether, vinyl isoamyl ether, vinyl-n-octadecyl ether, vinylcyclohexyl ether, ethylene glycol monobutyl vinyl ether, triethylene glycol monomethyl vinyl ether; acrylamide, methacrylamide, N- (Meth)acrylamides such as hydroxymethylacrylamide, N-hydroxymethylmethacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, and N-butoxymethylacrylamide; triallyl isocyanurate, diallyl phthalate, diallyl isophthalate, etc. Allyl compounds; (meth)acrylics such as 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate acid esters; hydroxyalkyl (meth)acrylates such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and pentaerythritol tri(meth)acrylate; methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, etc. Alkoxyalkylene glycol mono (meth) acrylates; ethylene glycol di (meth) acrylate, butanediol di (meth) acrylates, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, tri Alkylene polyol poly(meth)acrylates such as methylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate; diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, Polyoxyalkylene glycol poly(meth)acrylates such as ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane tri(meth)acrylate, etc. poly(meth)acrylates such as hydroxypivalic acid neopentylglycol ester di(meth)acrylate; and isocyanurate type poly(meth)acrylates such as tris[(meth)acryloxyethyl]isocyanurate.

Such a compound having an ethylenically unsaturated group is preferably a compound having a (meth)acryloyl group, that is, a (meth)acrylate compound. In addition, the (meth)acrylate compound is preferably bifunctional or higher because it has better heat resistance. Further, when the acrylic equivalent of the (meth)acrylate compound is 100 or more, the elongation rate becomes better, the halation is further suppressed, and the cured product is less likely to warp, which is preferable.

Such a compound having an ethylenically unsaturated group may be used alone or in combination of two or more. The compounding amount of the compound having an ethylenically unsaturated group is 1 to 80 parts by mass, more preferably 2 to 70 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A) in terms of solid content.

[(B) Photoinitiator]
As the photopolymerization initiator, any known and commonly used photopolymerization initiator can be used.

Examples of photopolymerization initiators include bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(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 (manufactured by IGM, Omnirad 819); 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4 ,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by IGM, Omnirad TPO ) and other monoacylphosphine oxides; 1-hydroxy-cyclohexylphenyl 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 hydroxyacetophenones such as -1-one; benzoins such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether; benzoin alkyl ethers; benzophenone, p- benzophenones such as methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone; acetophenone, 2,2-dimethoxy-2-phenyl lactophenone, 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 (IGM, Omnirad 369), 2-(dimethylamino)-2-[(4-methylphenyl)methyl) -1-[4-(4-morpholinyl)phenyl]-1-butanone, N,N-dimethylaminoacetophenone and other acetophenones; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2 ,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone and other thioxanthones; -anthraquinones such as amyl anthraquinone and 2-aminoanthraquinone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, p-dimethylbenzoic acid ethyl ester, etc. benzoic acid esters; 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl) -9H-carbazol-3-yl]-,1-(O-acetyloxime) (manufactured by BASF Japan, IRGACURE OXE-02) and other oxime esters; bis(η5-2,4-cyclopentadien-1-yl )-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyr -1-yl)ethyl)phenyl]titanium; phenyldisulfide 2-nitrofluorene, butyroin, anisoine ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide and the like. These photopolymerization initiators may be used alone or in combination of two or more.

The amount of the photopolymerization initiator compounded is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 30 parts by mass, based on 100 parts by mass of the (A) alkali-soluble resin in terms of solid content.

(Photopolymerization inhibitor)
The curable resin composition of the present invention preferably contains a photopolymerization inhibitor in addition to the components (A) and (B), which suppresses light scattering (so-called halation) during exposure and improves resolution. can improve sexuality.

The photopolymerization inhibitor is not particularly limited, and known and commonly used ones can be used.
Specifically, p-benzoquinone, naphthoquinone, di-t-butyl paracresol, hydroquinone monomethyl ether, α-naphthol, 4-methoxy-1-naphthol, acetamidine acetate, hydrazine hydrochloride, trimethylbenzylammonium chloride, di Nitrobenzene, picric acid, quinonedioxime, pyrogallol, tannic acid, resorudin, cupferron, phenothiazine, and the like. Among them, quinone photopolymerization inhibitors such as p-benzoquinone, naphthoquinone, hydroquinone monomethyl ether and quinonedioxime, and naphthol photopolymerization inhibitors such as α-naphthol and 4-methoxy-1-naphthol are preferred. A photopolymerization inhibitor may be used individually by 1 type, and may be used in combination of 2 or more type.

The amount of the photopolymerization inhibitor compounded is 0.005 to 20 parts by mass, more preferably 0.01 to 10 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A), in terms of solid content.

[(C) thermosetting compound]
The curable resin composition of the present invention contains (C) a thermosetting compound. This thermosetting compound can improve various properties of the cured product, such as heat resistance and insulation reliability, by further thermosetting the photocured composition. Examples of such thermosetting compounds include known and commonly used thermosetting compounds such as amino resins, melamine resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy compounds, polyfunctional oxetane compounds, and episulfide resins. can be used. Among them, epoxy compounds, oxetane compounds and maleimide compounds are preferably used, and they may be used in combination.

As the epoxy compound, a known and commonly used compound having one or more epoxy groups can be used, and among them, compounds having two or more epoxy groups are preferred. For example, monoepoxy compounds such as butyl glycidyl ether, phenylglycidyl ether, glycidyl (meth)acrylate, bisphenol A type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin , cycloaliphatic epoxy resin, trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, biphenyl-4,4'-diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol or propylene glycol Diglycidyl ether, sorbitol polyglycidyl ether, tris (2,3-epoxypropyl) isocyanurate, triglycidyl tris (2-hydroxyethyl) isocyanurate and other compounds having two or more epoxy groups in one molecule. be done.

As the oxetane compound, a known and commonly used compound having an oxetanyl group can be used. ) oxetane (OXT-211 manufactured by Toagosei Co., Ltd.), 3-ethyl-3-(2-ethylhexyloxymethyl) oxetane (OXT-212 manufactured by Toagosei Co., Ltd.), 1,4-bis {[(3-ethyl-3 -oxetanyl)methoxy]methyl}benzene (OXT-121 manufactured by Toagosei Co., Ltd.), bis(3-ethyl-3-oxetanylmethyl) ether (OXT-221 manufactured by Toagosei Co., Ltd.), and the like. Furthermore, phenol novolac type oxetane compounds and the like are also included. The oxetane compound may be used in combination with the epoxy compound, or may be used alone.

As the maleimide compound, known and commonly used compounds such as polyfunctional aliphatic/alicyclic maleimides and polyfunctional aromatic maleimides can be used. Among them, bifunctional or higher maleimide compounds (polyfunctional maleimide compounds) are preferred.
Polyfunctional aliphatic/alicyclic maleimides include, for example, N,N'-methylenebismaleimide, N,N'-ethylenebismaleimide, tris(hydroxyethyl)isocyanurate and aliphatic/alicyclic maleimide carboxylic acids. isocyanurate skeleton maleimide ester compound obtained by dehydration esterification of isocyanurate skeleton poly(isocyanurate skeleton poly) such as isocyanurate skeleton maleimide urethane compound obtained by urethanizing tris(carbamatehexyl) isocyanurate and aliphatic/alicyclic maleimide alcohol Maleimides; isophorone bisurethane bis(N-ethylmaleimide), triethylene glycol bis(maleimidoethyl carbonate), aliphatic/alicyclic maleimide carboxylic acids and various aliphatic/alicyclic polyols are dehydrated and esterified, or aliphatic Aliphatic/alicyclic polymaleimide ester compounds obtained by transesterification of aliphatic/alicyclic maleimide carboxylic acid esters with various aliphatic/alicyclic polyols; aliphatic/alicyclic maleimide carboxylic acids and various Aliphatic/alicyclic polymaleimide ester compounds obtained by ether ring-opening reaction with aliphatic/alicyclic polyepoxide; and aliphatic/alicyclic polymaleimide urethane compounds obtained by chemical reaction.

Examples of polyfunctional aromatic maleimides include aromatic polymaleimide ester compounds obtained by dehydration esterification of maleimide carboxylic acid and various aromatic polyols, or transesterification of maleimide carboxylic acid esters and various aromatic polyols; Aromatic polymaleimide ester compounds obtained by ether ring-opening reaction of carboxylic acid and various aromatic polyepoxides; Aromatic polymaleimide urethane compounds obtained by urethanization reaction of maleimide alcohol and various aromatic polyisocyanates, etc. and aromatic polyfunctional maleimides.
Among such polyfunctional aromatic maleimides, liquid polyfunctional aromatic maleimides are more preferable in terms of better elongation. Here, the liquid polyfunctional aromatic maleimide is a polyfunctional aromatic having a viscosity of 50,000 cp or less as measured by a cone-plate viscometer (TVH-33H manufactured by Toki Sangyo Co., Ltd.) at 60° C. and 5 rpm. It is called maleimide.

The thermosetting compounds as described above may be used singly or in combination of two or more. The amount of the thermosetting compound is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 100 parts by mass, more preferably 1 to 60 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A) in terms of solid content. Parts by mass are more preferred. In particular, when a maleimide compound is blended as a thermosetting compound, the amount of the maleimide compound compounded is preferably 0.1 to 50 parts by mass, based on 100 parts by mass of the alkali-soluble resin (A), in terms of solid content. It is preferably 0.2 to 20 parts by mass.

(Thermosetting catalyst)
The curable resin composition of the present invention can contain a thermosetting catalyst in addition to (C) the thermosetting compound. 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-dimethyl Amine compounds such as benzylamine and 4-methyl-N,N-dimethylbenzylamine; hydrazine compounds such as adipic dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine.

Also, 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/isocyanuric acid adducts, 2,4-diamino-6-methacryloyloxyethyl-S-triazine/isocyanuric acid adducts and other S-triazine derivatives, etc. can be used.

Commercially available products include, for example, 2MZ-AP, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, and 2P4MHZ manufactured by Shikoku Kasei Co., Ltd. (all are trade names of imidazole compounds), U-CAT3503N and U manufactured by San-Apro Co., Ltd. -CAT3502T (all are trade names of dimethylamine blocked isocyanate compounds), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof), and the like. In particular, it is not limited to these, as long as it promotes the reaction of the thermosetting catalyst for epoxy compounds and oxetane compounds, or other thermosetting components, either alone or in combination of two or more. You can use it.

The content of the thermosetting catalyst is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 20 parts by mass in terms of solid content, per 100 parts by mass of the alkali-soluble resin (A). When the amount of the thermosetting catalyst is within the range of 0.1 to 20 parts by mass, the balance between storage stability and curability is excellent.

[(D-1) Inorganic filler with an average particle size of 0.5 to 6 μm that is decomposed or dissolved by a roughening agent]
The curable resin composition of the present invention contains (D-1) an inorganic filler having an average particle size of 0.5 to 6 μm that is decomposed or dissolved by a roughening agent. In this specification, at least one selected from acids, alkalis, oxidizing agents, and organic solvents is used as the roughening agent. Moreover, the roughening treatment may serve as the desmear treatment. Here, the acid includes hydrochloric acid, sulfuric acid, nitric acid, and the like. Alkali include sodium hydroxide, potassium hydroxide and the like. Examples of the oxidizing agent include sodium permanganate, potassium permanganate, potassium dichromate, ozone and the like. Organic solvents include N-methyl-2-pyrrolidone, N,N-dimethylformamide, dimethylsulfoxide, methoxypropanol, dimethylformamide (DMF) and the like.

Examples of inorganic fillers that can be decomposed or dissolved by a roughening agent include magnesium oxide, calcium carbonate, zirconium silicate, zirconium oxide, and calcium hydroxide, with calcium carbonate being particularly preferred.

The inorganic filler (D-1) should have an average particle size of 0.5 to 6 μm, preferably 0.5 to 5 μm. When the thickness is 0.5 μm or more, the adhesion to the conductive circuit is improved. When the thickness is 6 μm or less, the resolution is improved, and fine conductor circuits can be formed and transmission loss can be reduced.

The average particle size of the inorganic filler (D-1) is the average particle size (D50) including not only the particle size of the primary particles but also the particle size of the secondary particles (aggregate), and is determined by a laser diffraction method. Measured D50 values. Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd. can be used as a measuring device using the laser diffraction method. The same applies to the average particle size of the inorganic filler (D-2) described later.

The inorganic filler (D-1) may be used alone or in combination of two or more. The amount of the inorganic filler (D-1) to be blended is preferably 10 to 200 parts by mass, more preferably 20 to 100 parts by mass in terms of solid content, per 100 parts by mass of the alkali-soluble resin (A).

[(D-2) Spherical inorganic filler not decomposed or dissolved by roughening agent]
The curable resin composition of the present invention contains (D-2) a spherical inorganic filler that is not decomposed or dissolved by a roughening agent.

Spherical inorganic fillers that are not decomposed or dissolved by the roughening agent include silica and alumina, with silica being particularly preferred.

The inorganic filler (D-2) may be spherical, and is not limited to true spheres. For example, a sphericity of 0.8 or more, which is measured as follows, is preferable, but is not limited to this.

Sphericity is measured as follows. That is, first, a photograph of spherical silica is taken with a scanning electron microscope (SEM), and from the area and peripheral length of the particles observed on the photograph, (sphericity) = {4π × (area) ÷ (periphery length) ² }. Specifically, an average value measured for 100 particles using an image processing device can be employed.

The inorganic filler (D-2) preferably has an average particle size of 4 μm or less. If it is 4 μm or less, the resolution will be better. More preferably, it is 1 μm or less.

The inorganic filler (D-2) may be used alone or in combination of two or more. The amount of the inorganic filler (D-2) to be blended is preferably 2 to 60 parts by mass per 100 parts by mass of the inorganic filler (D-1). If it is 60 parts by mass or less, the resolution will be better. When the content is 2 parts by mass or more, cracks in via hole openings after roughening treatment are suppressed. More preferably, it is 5 to 50 parts by mass.

(coupling agent)
The curable resin composition of the present invention can contain a coupling agent. As the coupling agent, a silane-based coupling agent, a titanium-based coupling agent, a zirconium-based coupling agent, an aluminum-based coupling agent, or the like can be used. Among them, silane coupling agents are preferred. Examples of organic reactive groups possessed by the coupling agent include vinyl groups, ethylenically unsaturated groups (unsaturated hydrocarbon groups) such as (meth)acrylic groups, alkoxy groups, epoxy groups, amino groups, thiourea groups, mercapto groups, and isocyanate groups. groups, imidazole groups, thiazole groups, triazole groups, etc., but thiourea groups and ethylenically unsaturated groups (unsaturated hydrocarbon groups) such as vinyl groups and (meth)acrylic groups are particularly preferred. Coupling agents may be used alone or in combination of two or more.

The amount of the silane coupling agent compounded is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass in terms of solid content, with respect to 100 parts by mass of the (A) alkali-soluble resin. is.

(Additive)
The curable resin composition of the present invention may optionally contain known and commonly used additives. Examples of this additive include inorganic fillers other than (D-1) and (D-2), organic fillers, adhesion imparting agents, acrylic or silicone leveling agents, antifoaming agents, thermal polymerization inhibitors, and UV absorbers. agents, flame retardants, antistatic agents, thixotropic agents, and the like. In addition, if necessary, titanium oxide, metal oxides, and metal hydroxides such as aluminum hydroxide can be blended as extender pigments for the purpose of imparting light reflectivity and flame retardancy. Further, known and commonly used colorants such as red, blue, green, yellow, white and black can be blended. Any of pigments, dyes, and dyes may be used as the coloring agent.

(Organic solvent)
The curable resin composition of the present invention can contain an organic solvent for the purpose of preparing the composition and adjusting the viscosity when the resin layer is formed by applying the composition onto a support 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 Glycol ethers such as ether, 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 Esters such as carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, and solvent naphtha; A known and commonly used organic solvent can be used. These organic solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

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

[Dry film]
The curable resin composition of the present invention can also be in the form of a dry film comprising a support (carrier) film and a dried resin layer composed of the above curable resin composition formed on the support film. .

As such a support film, a plastic film is used, and for example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, or the like can be used. The thickness of this support film is not particularly limited, but is generally selected appropriately within the range of 10 to 150 μm.

The dry film of the invention can be produced, for example, as follows.
First, the above-mentioned curable resin composition constituting the dry film of the present invention is diluted with an organic solvent to adjust the viscosity to an appropriate value, and then a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, and a reverse coater are used. It is applied to a uniform thickness on the support film by a coater, transfer roll coater, gravure coater, spray coater or the like.
Next, the coating film of the curable resin composition applied on the support film is dried at a temperature of 50 to 130° C. for 1 to 30 minutes to form a resin layer composed of a dry coating film on the support film. Films can be produced. Here, the thickness of the coating film is not particularly limited, but is generally selected appropriately within the range of 10 to 150 μm, preferably 15 to 60 μm, in terms of film thickness after drying.

The dry film of the present invention produced in this manner is composed of a PET film having a thickness of 30 to 50 μm and a curable resin composition layer (resin layer) having a thickness of 15 μm. It is preferable that the light transmittance in is 90% or less. By having such light transmittance, the photocurability of the resin layer is stabilized and the resolution is improved.

The dry film of the present invention preferably has a resin layer with a minimum melt viscosity of 10 to 2000 dPa·s at 70°C to 120°C. By having such a melt viscosity, it is possible to obtain sufficient filling properties for circuit irregularities in the laminate.

In the dry film of the present invention, after forming a resin layer composed of a curable resin composition on a support film, for the purpose of preventing dust from adhering to the surface of the resin layer, the surface of the resin layer is further coated with It is preferred to laminate a peelable protective (cover) film.
As the peelable protective film, any film having an adhesive strength smaller than that between the resin layer and the support film may be used, and for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, or the like can be used.

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

[Cured product]
The cured product of the present invention is obtained by curing the curable resin composition of the present invention or the resin layer of the dry film of the present invention.

[Printed wiring board]
The printed wiring board of the present invention has the curable resin composition of the present invention or a cured product of the dry film resin layer of the present invention. The printed wiring board of the present invention can be produced, for example, as follows.
First, the dry film of the present invention is laminated on a wiring substrate having a circuit formed thereon using a laminator or the like so that the resin layer faces the substrate side. In this step, instead of laminating the dry film of the present invention, the curable resin composition of the present invention is applied onto a circuit board and dried to form a tack-free resin layer. good too.
Examples of the wiring board include printed wiring boards and flexible printed wiring boards in which circuits such as copper are formed in advance on various base materials such as glass cloth epoxy and nonwoven fabric epoxy.

Next, the resin layer formed on the wiring board is pattern-exposed by irradiating active energy rays through a photomask having a predetermined pattern after peeling off the support film or from above the support film.
Here, the exposure device used for the irradiation of the active energy rays may be any device that is equipped with a high-pressure mercury lamp, a metal halide lamp, or the like as a light source and irradiates ultraviolet rays in the range of 350 to 450 nm. Imaging exposure) equipment can also be used. Also, the exposure amount varies depending on the film thickness and the like, but is generally in the range of 10 to 1000 mJ/cm ² , preferably in the range of 20 to 800 mJ/cm ² .

Next, the unexposed area is developed with an alkaline aqueous solution (eg, 0.3 to 3% by mass aqueous solution of sodium carbonate) to form a patterned photocured material.
Here, as a developing method, a dipping method, a shower method, a spray method, or the like can be used, and as a developing solution, an alkaline aqueous solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, or potassium carbonate can be used. can.

Furthermore, the obtained patterned cured product is cured by heating (for example, 100 to 180 ° C.) or by irradiation with active energy rays, resulting in a cured film excellent in various properties such as adhesion and hardness. can be formed. In this manner, an interlayer insulating layer having finer and smaller via hole openings can be formed on the wiring substrate.
Here, heat treatment such as heat curing can be performed using a hot air circulating drying furnace, an IR furnace, or the like.

Further, if necessary, conductive circuits including via holes and interlayer insulating layers are alternately built up, and finally a solder resist is formed to manufacture a printed wiring board.

As described above, the curable resin composition of the present invention is useful as a material for an interlayer insulating layer, and is also used for forming a pattern layer as a permanent coating for printed wiring boards such as solder resists and coverlays. can also be used for In addition, the curable resin composition of the present invention has excellent resolution and small surface roughness, while providing excellent adhesion (high peel strength) to a conductive circuit formed by copper plating. Therefore, it can be suitably used as an interlayer insulating material for semiconductor packages, which require fine circuit formation and transmission loss reduction. In addition, the curable resin composition of the present invention suppresses cracking of via hole openings after surface roughening treatment and improves insulation between via holes, so that it is also suitable for use in printed wiring boards with high-density wiring. be able to.

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 and comparative examples. In the following, "parts" and "%" are based on mass unless otherwise specified.

[Synthesis of alkali-soluble resin]
(Synthesis Example 1: Alkali-soluble acrylate-added amideimide resin (alkali-soluble resin A-1))
103.5 g of diethylene glycol monoethyl ether acetate, 222.0 g of isophorone diisocyanate, and 192.0 g of trimellitic anhydride were charged in a four-necked flask equipped with a stirrer, thermometer, and condenser, and the temperature was raised to 120°C while stirring. did. Vigorous foaming began at around 60° C., and the contents of the flask gradually became transparent. The reaction was carried out at 120°C for 5 hours, and when the NCO% in the system reached 9.0 mass%, the system was cooled to 40°C. Furthermore, 166.4 g of diethylene glycol monoethyl ether acetate and 1.0 g of methyl hydroquinone were added, and 234.7 g of Aronix M-305 (manufactured by Toagosei Co., Ltd., OH equivalent: 467.5) was added thereto, while being careful of heat generation. The temperature was raised to 80°C. After reacting at 80° C. for 9 hours, it was confirmed by infrared absorption spectrum that absorption of isocyanate at 2270 cm ⁻¹ had disappeared, and a resin solution of alkali-soluble resin A-1 was obtained as a light yellow transparent liquid. The non-volatile content was 42%, the acid value of the solid content was 68.4 mgKOH/g, and the weight average molecular weight was about 1,524 (converted to polystyrene).

(Synthesis Example 2: Phenol-started carboxyl group-containing photosensitive resin (alkali-soluble resin A-2))
An autoclave equipped with a thermometer, a nitrogen introduction device and an alkylene oxide introduction device, and a stirring device was charged with 119.4 g of novolak cresol resin (Showol CRG951 manufactured by Showa Denko Co., Ltd., OH equivalent: 119.4) and 1.19 g of potassium hydroxide. and 119.4 g of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 g of propylene oxide was gradually added dropwise and reacted at 125-132° C. and 0-4.8 kg/cm ² for 16 hours. After cooling to room temperature, 1.56 g of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide. A propylene oxide reaction solution of a novolak-type cresol resin was obtained. This was obtained by adding an average of 1.08 mol of alkylene oxide per equivalent of phenolic hydroxyl group.
Next, 293.0 g of the alkylene oxide reaction solution of the novolak type cresol resin obtained, 43.2 g of acrylic acid, 11.53 g of methanesulfonic acid, 0.18 g of methylhydroquinone and 252.9 g of toluene were mixed with a stirrer, a thermometer and air. The mixture was charged into a reactor equipped with a blowing tube, air was blown in at a rate of 10 ml/min, and the mixture was reacted at 110° C. for 12 hours while stirring. 12.6 g of water was distilled out as an azeotrope with toluene, which was produced by the reaction. After cooling to room temperature, the resulting reaction solution was neutralized with 35.35 g of a 15% aqueous sodium hydroxide solution and then washed with water. After that, the toluene was removed by an evaporator while replacing it with 118.1 g of diethylene glycol monoethyl ether acetate to obtain a novolac type acrylate resin solution. Next, 332.5 g of the obtained novolak-type acrylate resin solution and 1.22 g of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing pipe, and air was blown at a rate of 10 ml/min. While stirring, 60.8 g of tetrahydrophthalic anhydride was gradually added and reacted at 95 to 101° C. for 6 hours to obtain a resin solution of carboxyl group-containing photosensitive resin A-2. The non-volatile content was 65%, the acid value of the solid content was 88 mgKOH/g, and the weight average molecular weight was about 8,000 (converted to polystyrene).

(Synthesis Example 3: Epoxy-started carboxyl group-containing photosensitive resin (alkali-soluble resin A-3))
220 g of a cresol novolak epoxy resin (Epiclon N-695, manufactured by Dainippon Ink and Chemicals, Inc., epoxy equivalent: 220) is placed in a four-necked flask equipped with a stirrer and a reflux condenser, and 214 g of carbitol acetate is added. Dissolved by heating. Next, 0.1 g of hydroquinone as a polymerization inhibitor and 2.0 g of dimethylbenzylamine as a reaction catalyst were added. This mixture was heated to 95 to 105° C., 72 g of acrylic acid was gradually added dropwise, and reacted for 16 hours. This reaction product was cooled to 80 to 90° C., 106 g of tetrahydrophthalic anhydride was added, reacted for 8 hours, cooled, and taken out.
A resin solution of the carboxyl group-containing photosensitive resin A-3 thus obtained was obtained. The non-volatile content was 65%, the acid value of the solid content was 100 mgKOH/g, and the weight average molecular weight was about 3,500 (converted to polystyrene).

(Synthesis Example 4: Carboxyl group-containing copolymerized photosensitive resin (alkali-soluble resin A-4))
A 2-liter separable flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen inlet tube was charged with 900 g of diethylene glycol dimethyl ether and t-butylperoxy 2-ethylhexanoate (Perbutyl O manufactured by NOF CORPORATION). 21.4 g was charged, and after heating to 90° C., 309.9 g of methacrylic acid, 116.4 g of methyl methacrylate, and 109.8 g of lactone-modified 2-hydroxyethyl methacrylate (PLAXEL FM1 manufactured by Daicel Chemical Industries, Ltd.) were added to bis(4 -t-Butylcyclohexyl)peroxydicarbonate (Perloyl TCP manufactured by NOF Corporation) 21.4 g was added dropwise to diethylene glycol dimethyl ether over 3 hours, and further aged for 6 hours to obtain a carboxyl group-containing copolymer resin solution. . The reaction was performed under nitrogen atmosphere.
Next, 363.9 g of 3,4-epoxycyclohexylmethyl acrylate (Cycromer A200 manufactured by Daicel Chemical Industries, Ltd.), 3.6 g of dimethylbenzylamine, and 1.80 g of hydroquinone monomethyl ether were added to the above carboxyl group-containing copolymer resin solution. The epoxy ring-opening addition reaction was carried out by raising the temperature to ℃ and stirring. After 16 hours, a resin solution of carboxyl group-containing copolymer photosensitive resin A-4 was obtained. The nonvolatile content was 53.8%, the acid value of the solid content was 108.9 mgKOH/g, and the weight average molecular weight was 25,000 (converted to polystyrene).

(Examples 1-4, 6-12 , Reference Example 5, Comparative Examples 1-4)
Each component was blended according to the formulations shown in Tables 1 and 2 below, premixed with a stirrer, and then kneaded with a three-roll mill to disperse. Examples 1 to 4, 6 to 12, Reference Example 5, Comparative The curable resin compositions of Examples 1-4 were prepared. In addition, the compounding quantity in a table|surface shows a mass part.

*1: Alkali-soluble resin A-1 synthesized in Synthesis Example 1 above
*2: Alkali-soluble resin A-2 synthesized in Synthesis Example 1 above
*3: Alkali-soluble resin A-3 synthesized in Synthesis Example 1 above
*4: Alkali-soluble resin A-4 synthesized in Synthesis Example 1 above
*5: IGM Omnirad TPO (acylphosphine oxide photopolymerization initiator)
*6: HP-7200 manufactured by DIC (dicyclopentadiene type epoxy resin)
*7: Brilliant 1500 manufactured by Shiraishi Calcium Co., Ltd. (average particle size 0.15 μm)
*8: Softon 3200 manufactured by Shiraishi Calcium Co., Ltd. (average particle size 0.70 μm)
*9: Softon 2600 manufactured by Shiraishi Calcium Co., Ltd. (average particle size 0.85 μm)
*10: Softon 2200 manufactured by Shiraishi Calcium Co., Ltd. (average particle size 1.0 μm)
* 11: BF-100 manufactured by Shiraishi Calcium Co., Ltd. (average particle size 3.6 μm)
* 12: BF-200 manufactured by Shiraishi Calcium Co., Ltd. (average particle size 5.0 μm)
* 13: BF-300 manufactured by Shiraishi Calcium Co., Ltd. (average particle size 8.0 μm)
*14: SO-E2 manufactured by Admatechs (average particle size 0.55 μm)
*15: SO-E6 manufactured by Admatechs (average particle size 2.0 μm)
* 16: DAW-03 manufactured by Denka (average particle size 4.0 μm)
*17: Hugh Rex WX manufactured by Tatsumori Co., Ltd. (average particle size 1.0 μm)
* 18: Shin-Etsu Chemical Co., Ltd. X-12-1116 (thiourea skeleton-containing silane coupling agent)
* 19: KBM-503 (3-methacryloxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.
* 20: QS-30 (4-methoxy-1-naphthol) manufactured by Kawasaki Chemical Industry Co., Ltd.

(Preparation of dry film)
The obtained photocurable resin composition of each example , reference example and each comparative example was applied onto a support film (PET film, Cosmoshine A4100 manufactured by Toyobo Co., Ltd., thickness of 50 μm), dried at 80° C. for 20 minutes, and the thickness was reduced. A resin layer made of a photocurable resin composition having a thickness of 20 μm was formed. Then, a protective film was laminated on the resin layer to prepare a dry film for evaluation test.

(Resolution)
The protective film of the evaluation test dry film obtained in each example , reference example and each comparative example was peeled off and laminated on a copper solid substrate using CVP-300 manufactured by Nikko Materials Co., Ltd. at a temperature of 70 ° C. , an evaluation test substrate was produced.
Using a direct imaging exposure apparatus equipped with a high-pressure mercury lamp, this evaluation test substrate was exposed to a pattern with an opening diameter of 25 μmφ at an exposure amount of 170 mJ/cm ² , and then the support film was peeled off, followed by 1% by mass sodium carbonate. Using an aqueous developer, development was carried out for 100 seconds at a spray pressure of 0.2 MPa. After that, the film was irradiated with ultraviolet rays in a UV conveyer furnace under the condition of an accumulated exposure amount of 1000 mJ/cm ² , and further heat-cured at 180° C. for 60 minutes to prepare a resolution evaluation substrate.
Regarding the resolution evaluation substrate on which the resin layer having the pattern with the opening diameter of 25 μmφ is formed in this way, the top diameter and the bottom diameter of the opening are observed and measured at an angle of 45 degrees by SEM, and the resolution is evaluated. did. The evaluation criteria are as follows.
A: (bottom diameter / top diameter) is 0.8 or more and less than 0.9.
◯: (bottom diameter/top diameter) is 0.7 or more and less than 0.8.
Δ: (bottom diameter/top diameter) is 0.6 or more and less than 0.7.
x: (bottom diameter/top diameter) is less than 0.6.

(Evaluation of cracks around vias)
The substrate for evaluation of resolution produced in the evaluation of resolution was further subjected to surface roughening treatment, which will be described later, to produce a substrate for evaluation of cracks around vias. The roughened pattern with an opening diameter of 25 μmφ on the crack evaluation board around the via was observed with an SEM at an angle of 45 degrees to evaluate the presence or absence of cracks around the opening. The evaluation criteria are as follows.
⊚: There is no crack at the opening.
◯: Slight cracks are observed at the opening.
x: Many cracks are observed around the opening.

(peel strength)
Using a direct imaging exposure apparatus equipped with a high-pressure mercury lamp, the entire surface of the evaluation test substrate prepared in the evaluation of resolution was exposed at an exposure amount of 170 mJ/cm ² , and then the support film was peeled off. % sodium carbonate aqueous solution for 100 seconds at a spray pressure of 0.2 MPa. Then, it was irradiated with ultraviolet rays in a UV conveyor furnace under the condition of an integrated exposure amount of 1000 mJ/cm ² , and further cured by heating at 180° C. for 60 minutes.
The wiring board (cured resin layer-formed board) having the cured resin layer formed on the entire surface in this way is further subjected to a roughening treatment to be described later, and then a conductor layer is formed to form a peel strength measurement board (copper-plated board). Then, a cut having a width of 10 mm and a length of 100 mm was made in the conductor layer of the substrate for peel strength measurement, one end of the cut was partially peeled off, and a tensile tester (AGS-G100W manufactured by Shimadzu Corporation) was used. was used, and the load (kgf/cm) measured under the conditions of 1.0 mm/min tensile speed and 23° C. was defined as the peel strength in accordance with JISK7127, and adhesion was evaluated. The evaluation criteria are as follows.
○: The peel strength is 0.3 kgf/cm or more.
Δ: The peel strength is 0.15 kgf/cm or more and less than 0.3 kgf/cm.
x: The peel strength is less than 0.15 kgf/cm.

・ Roughening treatment The cured resin layer-formed substrate is soaked in a swelling liquid Swelling Dip Securigans P (aqueous solution of glycol ethers and sodium hydroxide) containing diethylene glycol monobutyl ether manufactured by Atotech Japan Co., Ltd. at 60 ° C. Soak for 5 minutes. Next, as a roughening liquid, Concentrate Compact P (KMnO ₄ : 60 g/L, NaOH: 40 g/L aqueous solution) manufactured by Atotech Japan was used and immersed at 60° C. for 10 minutes. Finally, as a neutralizing solution, Reduction Shoryusin Securigant P (aqueous solution of sulfuric acid) manufactured by Atotech Japan Co., Ltd. was used and immersed at 60° C. for 5 minutes. After that, drying was performed at 80° C. for 30 minutes.

・Formation of conductor layer First, electroless copper plating is applied in the following steps 1 to 6 (copper plating process using a chemical solution manufactured by Atotech Japan) on the cured resin layer formed substrate that has been roughened. did. The thickness of the formed electroless copper plating layer was 1 μm. Next, the evaluation test substrate on which the electroless copper plating layer was formed was subjected to heat treatment at 150° C. for 30 minutes, followed by electroplating of copper sulfate to form a conductor layer having a thickness of 25 μm. Finally, annealing treatment was performed at 180° C. for 60 minutes, and adhesion was evaluated.
1. Alkali Cleaning (Cleaning the Surface of the Insulating Layer and Adjusting Charge) Cleaning was performed at 60° C. for 5 minutes using Cleaning Cleaner Security 902 (trade name).
2. Soft Etching Process A sulfuric acid-acid sodium peroxodisulfate aqueous solution was used for processing at 30° C. for 1 minute.
3. Pre-dip (adjustment of surface charge of insulating layer for Pd application) step Pre. Dip Neoganth B (trade name) was used for 1 minute at room temperature. 4. Activator Application (Pd Application to the Surface of the Insulating Layer) Process Using Activator Neoganth 834 (trade name), treatment was performed at 35° C. for 5 minutes.
5. Reduction (reduction of Pd applied to the insulating layer) process Reducer Neoganth WA (trade name) and Reducer Accelerator 810 mod. (trade name) and treated at 30° C. for 5 minutes. 6. Electroless copper plating (Cu is deposited on the surface of the insulating layer (Pd surface)) process Basic Solution Printganth MSK-DK (trade name), Copper solution Printganth MSK (trade name), and Stabilizer Printganth MSK-DK (trade name) and Reducer Cu (trade name) at 35° C. for 20 minutes.

(B-HAST resistance)
The protective film of the evaluation test dry film obtained in each example , reference example and each comparative example was peeled off, and a BT substrate on which a comb-shaped electrode (line/space = 12 µm/13 µm) was formed was applied to Nikko Materials Co., Ltd. After lamination at a temperature of 70° C. using CVP-300 manufactured by Epson, a direct imaging exposure device equipped with a high-pressure mercury lamp was used to expose areas other than the electrode terminals at an exposure amount of 170 mJ/cm ² , and then the support film was peeled off. After that, development was performed for 100 seconds using a 1 mass % sodium carbonate aqueous solution developer at a spray pressure of 0.2 MPa. After that, it was irradiated with ultraviolet rays in a UV conveyor furnace under the condition of an integrated exposure amount of 1000 mJ/cm ² and further heat-cured at 180° C. for 60 minutes to prepare a B-HAST resistance evaluation substrate. A voltage of 5 V was applied from the electrode terminals of this B-HAST resistance evaluation substrate, and the substrate was placed in a high-temperature and high-humidity chamber under an atmosphere of 130° C. and humidity of 85% to perform an HAST test in the chamber. The elapsed time when the in-tank insulation resistance value became less than 10 ⁶ Ω was evaluated according to the following criteria.
◎: more than 400 hours ○: 200 to 400 hours ×: less than 200 hours

As is clear from the results shown in Table 1, for Examples 1 to 4 and 6 to 12 using the dry film of the present invention, resolution, peel strength, crack suppression around vias, and B-HAST resistance were all improved. The result was satisfactory. On the other hand, in Comparative Example 1 in which the average particle size of the inorganic filler decomposed or dissolved by the roughening agent is less than 0.5 μm, sufficient peel strength cannot be obtained, and in Comparative Example 2 in which the average particle size exceeds 6 μm. , cracks occurred remarkably, and the resolution and B-HAST resistance were poor. When the inorganic filler that was not decomposed or dissolved by the roughening agent was not spherical, as shown in Comparative Example 3, significant cracks occurred, and the resolution and B-HAST resistance were poor. In Comparative Example 4, which does not contain the inorganic filler (D-2), cracks were significantly generated around the via.

Claims (6)

(A) an alkali-soluble resin;
(B) a photoinitiator;
(C) a thermosetting compound;
(D-1) an inorganic filler with an average particle size of 0.5 to 3.6 μm that is decomposed or dissolved by a roughening agent;
(D-2) a spherical inorganic filler that is not decomposed or dissolved by a roughening agent;
A curable resin composition comprising: 2. The curable resin composition according to claim 1, wherein (D-2) the spherical inorganic filler that is not decomposed or dissolved by the roughening agent is silica and/or alumina. 3. The curable resin composition according to claim 1, wherein (D-2) the spherical inorganic filler that is not decomposed or dissolved by the roughening agent has an average particle size of 4 μm or less. A dry film comprising a resin layer obtained from the curable resin composition according to any one of claims 1 to 3. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 3 or the resin layer of the dry film according to claim 4. A printed wiring board comprising the cured product according to claim 5 .