JP7191609B2 - Curable resin composition, cured product and printed wiring board - Google Patents

Description

TECHNICAL FIELD The present invention relates to a curable resin composition (hereinafter also simply referred to as "composition"), a cured product and a printed wiring board.

BACKGROUND ART Conventionally, a curable resin composition that can be developed with an alkaline aqueous solution has been used as a material for forming a permanent film such as a solder resist on a printed wiring board by exposure and development (for example, Patent Document 1).

Such curable resin compositions are classified into a liquid type and a dry film type, and especially the liquid type curable resin composition has an advantage of low cost. Further, the method of applying this liquid type curable resin composition includes methods such as screen printing, curtain coating, and roll coating. has the advantage of being able to

JP 2005-241977

However, in the conventional method of applying a solder resist resin composition onto a substrate by a roll coating method, even if an ordinary antifoaming agent is added, air bubbles may be caught in the grooves of the coating roll. There is a problem that air bubbles are likely to be generated on the film surface and inside the coating film, leading to deterioration of insulation reliability. In addition, such a method also has a problem of causing poor appearance (deterioration of smoothness) due to cissing of the coating film and coating unevenness on the surface of the coating film. Furthermore, in the exposure process using a direct image exposure machine (DI exposure machine), the substrate adsorption force of the exposure table is stronger than that of the contact exposure device, and adsorption marks (so-called tack marks) are formed on the surface of the dry coating film in contact with the exposure table. There was a problem of poor appearance that it is easy to stick.
In particular, package substrates, on which wiring patterns are formed closely together at higher density, are becoming more precise, and there is concern that air bubbles caused by the roll coating method may deteriorate insulation reliability.
As described above, in the case of a curable resin composition for roll coating, it is a problem to reliably prevent appearance defects such as inclusion of air bubbles in the coating film surface or inside the coating film and deterioration of smoothness. ing.

The present invention was made to solve such problems, and its main purpose is to eliminate repelling of the coating film, uneven coating on the surface of the coating film, and tack marks on the surface of the dry coating film. To provide a curable resin composition capable of forming, by roll coating, a high-quality solder-resist coating film having good surface condition and excellent insulation reliability without air bubbles mixed inside the film.
Another object of the present invention is to provide a cured product and a printed wiring board obtained using the curable resin composition described above.

As a result of extensive studies aimed at achieving the above object, the inventors have found that, as a surface conditioner, at least two types of modified polydimethylsiloxanes having different numbers of repeating units (n) in the polydimethylsiloxane structure are combined and blended, The inventors have found that it is possible to obtain a high-quality coating film with a good surface condition and excellent insulation reliability while preventing air bubbles from entering the coating film surface and inside the coating film, and have completed the present invention.

That is, the curable resin composition of the present invention is a composition for roll coating, comprising (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) an organic solvent, and (D) a surface The (D) surface conditioner comprises (D-1) a modified polydimethylsiloxane obtained by organically modifying a polydimethylsiloxane in which n in the following general formula (1) is in the range of 2 to 27. , (D-2) A modified polydimethylsiloxane obtained by organically modifying a polydimethylsiloxane having n in the following general formula (1) in the range of 45 to 230.

Moreover, the cured product of the present invention is characterized by being obtained by curing the curable resin composition.

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

According to the present invention, there is no repelling of the coating film, uneven coating on the surface of the coating film, no tack marks on the surface of the dry coating film, no air bubbles are mixed into the coating film surface or inside the coating film, the surface condition is good, and the insulation reliability is good. It is possible to provide a curable resin composition capable of forming a high-quality solder resist coating film with excellent properties by roll coating, a cured product thereof, and a printed wiring board.

Embodiments of the present invention will be described in detail below.

(Curable resin composition)
The curable resin composition of the present invention comprises (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) an organic solvent, and (D) a surface modifier, wherein the (D) surface modifier is , (D-1) Modified polydimethylsiloxane obtained by organically modifying polydimethylsiloxane having n in the following general formula (1) in the range of 2 to 27 (hereinafter referred to as "(D-1) surface conditioner" (D-2) Modified polydimethylsiloxane obtained by organically modifying polydimethylsiloxane in which n in the following general formula (1) is in the range of 45 to 230 (hereinafter referred to as “(D-2) (also referred to as "surface conditioner").

Although the detailed mechanism is not clear, by using a combination of the surface conditioners (D-1) and (D-2) having different numbers of repeating units (n) in the polydimethylsiloxane structure, the number of repeating units (n) The surface conditioner (D-1) with a small number of repeating units (D-1) contributes to the prevention of inclusion of air bubbles inside the coating film, and the surface conditioner (D-2) with a large number of repeating units (n) is the coating film surface and the coating film It is believed that this contributes to the smoothness of the surface.

The curable resin composition of the present invention can be appropriately adjusted to have a viscosity suitable for the roll coating method. It is preferable to apply after adjusting to the range of . Viscosity may be measured with a cone and plate type viscometer. Although the method for adjusting the viscosity is not particularly limited, for example, it may be adjusted by blending an organic solvent.

[(A) Carboxyl Group-Containing Resin]
(A) As the carboxyl group-containing resin, conventionally known various carboxyl group-containing resins having a carboxyl group in the molecule can be used. In particular, a carboxyl group-containing photosensitive resin having an ethylenically unsaturated double bond in the molecule is preferable from the viewpoint of photocurability and development resistance. The ethylenically unsaturated double bonds are preferably derived from acrylic acid or methacrylic acid or derivatives thereof. When only a carboxyl group-containing resin having no ethylenically unsaturated double bonds is used, in order to make the composition photocurable, a compound having a plurality of ethylenically unsaturated groups in the molecule, i.e., photo It is necessary to use a polymerizable monomer together.
Specific examples of the carboxyl group-containing resin include the following compounds (both oligomers and polymers).

(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 polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

(3) 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 ( A carboxyl group-containing photosensitive urethane resin produced by a polyaddition reaction of a meth)acrylate or its partial acid anhydride modified product, a carboxyl group-containing dialcohol compound and a diol compound.

(4) During the synthesis of the resin (2) or (3), 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 carboxyl group-containing photosensitive urethane resin.

(5) During the synthesis of the resin of (2) or (3), one isocyanate group and one or more (meth)acryloyl groups are added in the molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate. A carboxyl group-containing photosensitive urethane resin that is terminally (meth)acrylated by adding a compound having

(6) A carboxyl group-containing photosensitive resin obtained by reacting (meth)acrylic acid with a polyfunctional (solid) epoxy resin having a functionality of 2 or more and adding a dibasic acid anhydride to the hydroxyl group present in the side chain.

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

(8) A bifunctional oxetane resin is reacted with a dicarboxylic acid such as adipic acid, phthalic acid, and hexahydrophthalic acid, and the resulting primary hydroxyl group is treated with a dibasic such as phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride. Carboxyl group-containing polyester resin to which acid anhydride is added.

(9) 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 resin obtained by reacting a polybasic acid anhydride such as an acid.

(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) A carboxyl group-containing photosensitive resin obtained by further adding a compound having one epoxy group and one or more (meth)acryloyl groups in one molecule to the resins of (1) to (11).
In this specification, (meth)acrylate is a generic term for acrylate, methacrylate and mixtures thereof, and the same applies to other similar expressions.

The acid value of the carboxyl group-containing resin is suitably in the range of 30-150 mgKOH/g, more preferably in the range of 50-120 mgKOH/g. When the acid value of the carboxyl group-containing resin is 30 mgKOH/g or more, alkali development is facilitated. can be reliably drawn, which is preferable.

Although the weight average molecular weight of the carboxyl group-containing resin differs depending on the resin skeleton, it is generally preferably in the range of 2,000 to 150,000, more preferably in the range of 5,000 to 100,000. When the weight average molecular weight is 2,000 or more, the development resistance of the film in the exposed area is improved and the resolution is excellent. On the other hand, when the weight average molecular weight is 150,000 or less, the solubility of the unexposed area is good, the resolution is excellent, and the storage stability may be improved. A weight average molecular weight can be measured by a gel permeation chromatography.

These carboxyl group-containing resins are not limited to those listed above, and one type may be used alone, or a plurality of types may be mixed and used. Among them, carboxyl group-containing resins such as the carboxyl group-containing resins (10) and (11) synthesized using phenolic compounds as starting materials are excellent in B-HAST resistance and PCT resistance, and can be preferably used.

[(B) Photoinitiator]
(B) As the photopolymerization initiator, any known one can be used. (B) A photoinitiator may be used individually by 1 type, and may be used in combination of 2 or more type.

Specific examples of the (B) photopolymerization initiator include bis-(2,6-dichlorobenzoyl)phenylphosphine oxide and 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)phenyl Phosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis- bisacylphosphine oxides such as (2,4,6-trimethylbenzoyl)-phenylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4, Monoacylphosphine oxides such as 6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide ; ethyl phenyl (2,4,6-trimethylbenzoyl)phosphinate, 1-hydroxy-cyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane -1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-hydroxy-2- Hydroxyacetophenones such as methyl-1-phenylpropan-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 benzophenones such as benzophenone, p-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-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl)-1-[4-(4 -morpholinyl)phenyl]-1-butanone, N,N-dimethylaminoacetophenone and other acetophenones; Thioxanthones such as chlorothioxanthone and 2,4-diisopropylthioxanthone; anthraquinones such as; acetophenone dimethyl ketal, benzyl dimethyl ketal and other ketals; ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, p-dimethylbenzoic acid ethyl ester and other benzoic acid esters; 2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl ]-,1-(O-acetyloxime) and other oxime esters; bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1- yl)phenyl)titanium, bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyrr-1-yl)ethyl)phenyl]titanium; phenyl disulfide 2- Nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide and the like can be mentioned.

The amount of the photopolymerization initiator to be blended is preferably 0.01 to 30 parts by mass in terms of non-volatile components with respect to 100 parts by mass of the carboxyl group-containing resin (A). When the amount is 0.01 part by mass or more, the resin composition has good photocurability, the coating film is difficult to peel off, and the coating film properties such as chemical resistance are also good. On the other hand, when the content is 30 parts by mass or less, the effect of reducing outgassing is obtained, the light absorption on the surface of the solder resist coating film is improved, and the deep-part curability is less likely to deteriorate. More preferably, it is 0.5 to 15 parts by mass.

[(C) organic solvent]
The curable resin composition of the present invention contains (C) an organic solvent for the purpose of preparing the composition and adjusting the viscosity when applied to a substrate or the like. Examples of organic solvents 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; , 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 carbi Esters such as tall 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; Conventional organic solvents can be used. These organic solvents can be used singly or in combination of two or more. Among them, carbitol acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, solvent naphtha, which has excellent solubility of resin components and does not easily thicken due to volatilization during work. is preferably used.

(C) The blending amount of the organic solvent is 20 to 35% of the total amount of the composition when adjusting the composition, and 30 to 45% of the total composition when applying to a substrate or the like. is preferred.

[(D) Surface conditioner]
In the curable resin composition of the present invention, (D) as a lower surface conditioner, (D-1) polydimethylsiloxane having n in the following general formula (1) in the range of 2 to 27 is organically modified. It contains polydimethylsiloxane and (D-2) modified polydimethylsiloxane obtained by organically modifying polydimethylsiloxane having n in the following general formula (1) in the range of 45 to 230. Examples of organic modification of polydimethylsiloxane (D-1) and (D-2) include polyether modification, polyester modification, aralkyl modification, and acrylic modification, each of which is used alone or in combination of two or more. be able to.

As modified polydimethylsiloxane (D-1) obtained by organically modifying polydimethylsiloxane, commercially available products may be used. , BYK-348, BYK-349, BYK-330, BYK-331 and other polyether-modified polydimethylsiloxanes, BYK-313, BYK-315N and other polyester-modified polydimethylsiloxanes, BYK-322 and other aralkyl-modified polydimethylsiloxanes Acrylic-modified polydimethylsiloxane such as BYK-UV3530 can be mentioned.

As modified polydimethylsiloxane obtained by organically modifying polydimethylsiloxane (D-2), commercially available products may be used. and acrylic-modified polydimethylsiloxane such as BYK-UV3510.

The amount of the modified polydimethylsiloxane (D-1) obtained by organically modifying the polydimethylsiloxane is 0.5 to 10 parts by mass, based on 100 parts by mass of the carboxyl group-containing resin (A), in terms of non-volatile components. Preferably. When the amount is 0.5 parts by mass or more, the generation of air bubbles on the coating film surface and inside the coating film is suppressed. On the other hand, when the content is 10 parts by mass or less, there is no inhibitory effect on tackiness, and uneven coating is suppressed. More preferably, it is 1 to 5 parts by mass.

The amount of the modified polydimethylsiloxane (D-2) obtained by organically modifying the polydimethylsiloxane is 0.5 to 10 parts by weight, based on 100 parts by weight of the carboxyl group-containing resin (A), in terms of non-volatile components. Preferably. When the amount is 0.5 parts by mass or more, the tackiness of the dry coating film surface is suppressed, and smoothness of the coating film surface is obtained. On the other hand, when the amount is 10 parts by mass or less, the inhibitory effect on defoaming is suppressed. More preferably, it is 1 to 5 parts by mass.

The mixing ratio of the surface conditioners (D-1) and (D-2) is preferably (D-1):(D-2)=1:4 to 4:1. By setting such a blending ratio, the filling property of the composition between the circuits is improved, air bubbles are suppressed from entering between the circuits, and excellent roll coatability is obtained.

[Photopolymerizable Monomer]
A photopolymerizable monomer can be added to the curable resin composition of the present invention. A photopolymerizable monomer is a compound having an ethylenically unsaturated double bond. Examples of such photopolymerizable monomers include alkyl (meth)acrylates such as 2-ethylhexyl (meth)acrylate and cyclohexyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; Hydroxyalkyl (meth)acrylates such as acrylates; mono- or di(meth)acrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol; hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane , dipentaerythritol, polyhydric alcohols such as trishydroxyethyl isocyanurate, or polyhydric (meth)acrylates of ethylene oxide or propylene oxide adducts thereof; phenoxyethyl (meth)acrylate, polyethoxydi(meth)acrylate of bisphenol A, etc. (Meth)acrylates of ethylene oxide or propylene oxide adducts of phenols; (meth)acrylates of glycidyl ethers such as glycerol diglycidyl ether, trimethylolpropane triglycidyl ether and triglycidyl isocyanurate; and melamine (meth)acrylates is mentioned.

A photopolymerizable monomer can be used individually by 1 type or in combination of 2 or more types. The content of the photopolymerizable monomer is preferably 0.5 to 20 parts by mass in terms of non-volatile components with respect to 100 parts by mass of the carboxyl group-containing resin (A). When the blending amount is 0.5 parts by mass or more, the photocurability is good, and pattern formation is facilitated in alkali development after irradiation with active energy rays. On the other hand, when the content is 20 parts by mass or less, halation is less likely to occur and good resolution can be obtained.

[Thermosetting component]
A thermosetting component can be blended into the curable resin composition of the present invention. Examples of thermosetting components include melamine resins, benzoguanamine resins, melamine derivatives, amino resins such as benzoguanamine derivatives, isocyanate compounds, blocked isocyanate compounds, cyclocarbonate compounds, epoxy compounds, oxetane compounds, episulfide resins, bismaleimide, carbodiimide resins, and the like. known thermosetting components can be used. Any known one can be used. Especially preferred are thermosetting components having multiple cyclic ether or cyclic thioether groups in the molecule.

A thermosetting component can be used individually by 1 type or in combination of 2 or more types. The amount of the thermosetting component is preferably 0.5 to 2.5 mol, more preferably 0.5 to 2.5 mol of functional groups of the thermosetting component that reacts with 1 mol of the carboxyl group contained in the carboxyl group-containing resin (A). 8 to 2.0 mol. When it is 0.5 mol or more, the heat resistance, mechanical strength, chemical resistance, and insulation reliability are excellent. When it is 2.5 mol or less, storage stability and developability are improved.

[Thermal curing catalyst]
A thermosetting catalyst can be blended in the curable resin composition of the present invention. Examples of thermosetting catalysts 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 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. 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 derivatives such as S-triazine/isocyanuric acid adducts and 2,4-diamino-6-methacryloyloxyethyl-S-triazine/isocyanuric acid adducts can also be used, and these adhesion-imparting agents are preferred. A compound that also functions is used in conjunction with a thermosetting catalyst.

A thermosetting catalyst can be used individually by 1 type or in combination of 2 or more types. The amount of the thermosetting catalyst is preferably 0.5 to 10 parts by mass, more preferably 1 to 8 parts by mass, based on 100 parts by mass of the carboxyl group-containing resin (A) in terms of non-volatile components. . When the amount is 0.5 parts by mass or more, the heat resistance is excellent. If it is 10 parts by mass or less, it leads to an improvement in storage stability.

[Inorganic filler]
An inorganic filler can be blended into the curable resin composition of the present invention. Moreover, as an inorganic filler, you may mix|blend the inorganic filler by which the surface treatment was carried out.

The inorganic filler is not particularly limited, and known and commonly used fillers such as silica, crystalline silica, Neuburg silica, aluminum hydroxide, glass powder, talc, clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica, Inorganic fillers such as aluminum hydroxide, barium sulfate, barium titanate, iron oxide, non-fibrous glass, hydrotalcite, mineral wool, aluminum silicate, calcium silicate, and zinc white can be used. Among them, barium sulfate is preferable in order to improve heat resistance and plating resistance. In order to improve thermal dimensional stability, silica is preferable, and spherical silica is more preferable because it has a small surface area and stress is dispersed over the entire surface, so that it is less likely to cause cracks.

The amount of the inorganic filler compounded is 40% by mass or less, preferably 5 to 35% by mass, in terms of non-volatile components, based on the total amount of the curable resin composition.

[Coloring agent]
The curable resin composition of the present invention may contain a coloring agent. As the coloring agent, conventionally known coloring agents such as red, blue, green, yellow, white and black can be used, and any of pigments, dyes and pigments can be used.

Specifically, those with a Color Index (C.I.; published by The Society of Dyers and Colorists) number can be mentioned.

Examples of red colorants include monoazo, disazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone colorants. Blue colorants include phthalocyanine-based, anthraquinone-based, and the like, and pigment-based compounds classified as pigments can be used. In addition to these, metal-substituted or unsubstituted phthalocyanine compounds can also be used. Green coloring agents include phthalocyanines, anthraquinones, and perylenes. In addition to these, metal-substituted or unsubstituted phthalocyanine compounds can also be used. Yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, and anthraquinone colorants. Examples of white colorants include rutile-type and anatase-type titanium oxide. Black colorants include carbon black, graphite, iron oxide, titanium black, anthraquinone, cobalt oxide, copper oxide, manganese, antimony oxide, nickel oxide, perylene, aniline, and sulfide. Molybdenum, bismuth sulfide, etc. In addition, coloring agents such as purple, orange, and brown may be added for the purpose of adjusting the color tone.

The content of the colorant is preferably 0.18 to 0.50% by mass in terms of non-volatile components based on the total amount of the curable resin composition, from the viewpoint of improving the hiding property of the cured product. When it is 0.18% by mass or more in terms of non-volatile components, the circuit hiding property is excellent, and when it is 0.50% by mass or less, the resolution is more excellent. More preferably, it is 0.20 to 0.40% by mass.

[Other optional ingredients]
The curable resin composition of the present invention may optionally further contain a photoinitiator aid, a cyanate compound, an elastomer, a mercapto compound, a urethanization catalyst, a thixotropic agent, an adhesion promoter, a block copolymer, and a chain transfer agent. , polymerization inhibitors, copper damage inhibitors, antioxidants, rust inhibitors, fine powdered silica, organic bentonite, thickeners such as montmorillonite, fluorine-based, polymer-based defoaming agents and/or leveling agents, silane-based , Titanium-, zirconium-, aluminum-, imidazole-, thiazole-, and triazole-based silane coupling agents; phosphinates, phosphoric acid ester derivatives, and phosphorus compounds such as phosphazene compounds. can be done. As these, those known in the field of electronic materials can be used.

The curable resin composition of the present invention may be one-component or two-component or more.

The curable resin composition of the present invention is preferably used for forming a cured film on electronic parts, particularly for forming a cured film on a printed wiring board, and more preferably for forming a permanent film. and more preferably used to form solder resists, interlayer insulating layers, and coverlays.

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

[Printed wiring board]
The printed wiring board of the present invention has a cured product obtained from the curable resin composition of the present invention. As a method for producing the printed wiring board of the present invention, for example, the curable resin composition of the present invention is adjusted to a viscosity suitable for the coating method using the above organic solvent, and is preferably roll-coated on the substrate. After coating according to the method, the organic solvent contained in the composition is volatilized and dried (temporary drying) at a temperature of 60 to 100° C. to form a tack-free resin layer.

Examples of the substrate include printed wiring boards and flexible printed wiring boards on which circuits are formed in advance using copper or the like, 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, and other materials such as copper-clad laminates for high-frequency circuits, and copper-clad laminates of all grades (FR-4, etc.) Plates, metal substrates, polyimide films, polyethylene terephthalate films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates and the like can also be used.

Volatilization drying performed after applying the curable resin composition of the present invention can be performed using a hot air circulation drying oven, an IR oven, a hot plate, a convection oven, etc. A method of bringing hot air into countercurrent contact and a method of blowing hot air onto the support from a nozzle) can be used.

After forming a resin layer on the substrate, it is selectively exposed to active energy rays through a photomask having a predetermined pattern, and the unexposed area is treated with a dilute alkaline aqueous solution (eg, 0.3 to 3% by mass aqueous solution of sodium carbonate). to form a pattern of the cured product. Furthermore, after irradiating the cured product with active energy rays, heat curing (e.g., 100 to 220 ° C), or after heat curing, irradiating the active energy rays, or final final curing (main curing) only by heat curing. Forms a cured film with excellent properties such as toughness and hardness.

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

Examples of the developing method include a dipping method, a shower method, a spray method, a brush method, and the like. Alkaline aqueous solutions such as ammonia and amines can be used.

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples. In the following description, "parts" and "%" are based on mass unless otherwise specified.

[Preparation of carboxyl group-containing resin solution A-1]
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 (manufactured by Showa Denko Co., Ltd., trade name "Shonol CRG951", OH equivalent: 119.4), water. 1.19 g of potassium oxide and 119.4 g of toluene were added, 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 from the alkylene oxide introduction device, and the mixture was reacted at 125 to 132° C. and 0 to 4.8 kg/cm ² for 16 hours.
After that, 1.56 g of 89% phosphoric acid was added to and mixed with the reaction solution cooled to room temperature to neutralize the potassium hydroxide, resulting in a solid content of 62.1% and a hydroxyl value of 182.2 g/eq. 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.
293.0 g of the alkylene oxide reaction solution of the novolak type cresol resin thus 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 an air-blowing tube. and reacted at 110° C. for 12 hours while blowing air at a rate of 10 ml/min and stirring.
Water produced by the reaction distilled as an azeotrope with toluene, and was 12.6 g.
Thereafter, the resulting reaction solution was cooled to room temperature, neutralized with 35.35 g of 15% aqueous sodium hydroxide solution, and then washed with water. Thereafter, the toluene was distilled off while replacing toluene with 118.1 g of carbitol acetate using an evaporator to obtain a novolak 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 95-101° C. for 6 hours. A carboxyl group-containing resin solution (A-1) having a solid acid value of 88 mgKOH/g and a solid content of 70% was obtained.

[Preparation of carboxyl group-containing resin solution A-2]
To 600 g of carbitol acetate, 1070 g of an ortho-cresol novolac type epoxy resin (manufactured by DIC, EPICLON N-695, softening point 95° C., epoxy equivalent weight 214, average functional group number 7.6) (number of glycidyl groups (total number of aromatic rings): 5. 0 mol), 360 g (5.0 mol) of acrylic acid, and 1.5 g of hydroquinone were charged, heated to 100° C. with stirring, and dissolved until uniform.
Next, 4.3 g of triphenylphosphine was added to the above solution, heated to 110° C., and reacted for 2 hours. After that, the temperature was raised to 120° C. and the reaction was further carried out for 12 hours.
415 g of an aromatic hydrocarbon (Solvesso 150) and 456.0 g (3.0 mol) of tetrahydrophthalic anhydride were added to the resulting reaction solution and reacted at 110° C. for 4 hours. After cooling, the solid content acid value was 89 mg KOH. /g and a carboxyl group-containing resin solution (A-2) having a solid content of 65% was obtained.

[Examples 1 to 9, Comparative Examples 1 to 10]
Each component was blended according to the formulation shown in Table 1 below, premixed with a stirrer, dispersed with a three-roll mill, and kneaded to prepare a photocurable resin composition. The compounding amount in the table indicates parts by mass. The prepared photocurable resin compositions of Examples and Comparative Examples were evaluated as follows.

<Evaluation board manufacturing method>
The resin compositions of Examples 1 to 9 and Comparative Examples 1 to 10 were each diluted with diethylene glycol monomethyl ether acetate to a viscosity of about 50 to 60 dPa·s (measurement temperature 25° C.) with a cone-plate viscometer.
The diluted composition was chemically polished on a printed wiring board having L (line)/S (space) = 100 µm/100 µm and a thickness of 35 µm, on which a comb circuit was formed. A roll was used and the coating was applied at a printing speed of 2 m/min.

<Anti-foaming during application>
After the evaluation substrate was produced, the state of bubble generation between the circuits was visually observed and evaluated according to the following criteria.
◯: There is no air bubble between the circuits.
x: Bubbles were generated between the circuits.

<Surface condition>
After the evaluation board was prepared, it was dried at 80° C. for 30 minutes, and the coating film surface state of the printed wiring board having an unexposed solder resist layer was visually observed, and the surface state was evaluated according to the following criteria.
◯: There is no unevenness in the surface condition.
x: Unevenness occurs in the surface condition.

<Bubbles on the coating surface>
After the evaluation board is prepared, it is dried at 80° C. for 30 minutes, and the wiring board is exposed using a predetermined negative pattern using an exposure device equipped with a high-pressure mercury lamp (short arc lamp) with a reference exposure amount, and then A 1 wt % Na ₂ CO ₃ aqueous solution at 30° C. was developed under conditions of a spray pressure of 2 kg/cm ² for 60 seconds to obtain a resist pattern. After the substrate was cured by heating at 150° C. for 60 minutes, it was irradiated with ultraviolet rays in a UV conveyor furnace under the condition of an integrated exposure amount of 1000 mJ/cm ² .
Air bubbles on the coating film surface of this substrate were observed with a stereoscopic microscope (observation magnification of 10 times) and evaluated according to the following criteria.
◯: There are no air bubbles on the surface.
x: Bubbles were generated on the surface.

<Bubbles inside the coating>
The cross section of the coating film of the wiring board obtained by the same method as <Evaluation of air bubbles on the surface of the coating film> was observed with an electron microscope (observation magnification of 1000), and air bubbles inside the coating film were evaluated according to the following criteria.
Good: Observation at 1000 times magnification was performed at 5 locations, and less than 5 bubbles were generated at 5 locations.
x: Observation at 1000 times magnification was performed at 5 locations, and 5 or more bubbles were observed at 5 locations.

<Tack evaluation>
After the evaluation board was prepared, it was dried at 80° C. for 30 minutes, and the wiring board was exposed using a DI exposure machine (Mms-60 manufactured by Orc Manufacturing Co., Ltd.), and then evaluated for sticking to the exposure table according to the following criteria. did.
◯: No sticking to the exposure table.
x: Sticking to the exposure table was confirmed.

These evaluation results are also shown in the table below.

＊１）ＴＰＯ（ＩＧＭ社製、Ｏｍｎｉｒａｄ ＴＰＯ、アシルホスフィンオキサイド）
＊２）ジプロピレングリコールモノメチルエーテル
＊３）ＢＹＫ－３２２（ビックケミー・ジャパン（株）製）
＊４）ＢＹＫ－３３０（ビックケミー・ジャパン（株）製）
＊５）ＢＹＫ－３３１（ビックケミー・ジャパン（株）製）
＊６）ＢＹＫ－３３３（ビックケミー・ジャパン（株）製）
＊７）ＢＹＫ－３７７（ビックケミー・ジャパン（株）製）
＊８）ＢＹＫ－ＵＶ３５１０（ビックケミー・ジャパン（株）製）
＊９）ＫＳ－６６（信越化学工業（株）製）
＊１０）ＢＹＫ－０６６Ｎ（ビックケミー・ジャパン（株）製、一般式（１）で表される構造を有するが、ｎ＝３８０～１５００である表面調整剤）
＊１１）ポリフローＮｏ．９０（共栄社化学（株）製）
＊１２）Ｎ－７７０（ＤＩＣ（株）製、フェノ－ルノボラック型エポキシ樹脂、軟化点６５～７５℃、エポキシ当量１８８）
＊１３）ＹＸ－４０００（三菱ケミカル（株）製、ビフェニル型エポキシ樹脂、融点１０５℃、エポキシ当量１９０）
＊１４）ＳＯ－Ｃ２（（株）アドマテックス製、球状シリカ、平均粒子径０．４５～０．６５μｍ）
＊１５）Ｂ－３０（堺化学工業（株）製、硫酸バリウム）
＊１６）ＤＰＨＡ（ジペンタエリスリトールヘキサアクリレート）

*1) TPO (OMNIRAD TPO, manufactured by IGM, acylphosphine oxide)
*2) Dipropylene glycol monomethyl ether *3) BYK-322 (manufactured by BYK-Chemie Japan Co., Ltd.)
*4) BYK-330 (manufactured by BYK-Chemie Japan Co., Ltd.)
*5) BYK-331 (manufactured by BYK-Chemie Japan Co., Ltd.)
*6) BYK-333 (manufactured by BYK-Chemie Japan Co., Ltd.)
*7) BYK-377 (manufactured by BYK-Chemie Japan Co., Ltd.)
*8) BYK-UV3510 (manufactured by BYK-Chemie Japan Co., Ltd.)
*9) KS-66 (manufactured by Shin-Etsu Chemical Co., Ltd.)
*10) BYK-066N (manufactured by BYK-Chemie Japan Co., Ltd., a surface conditioner having a structure represented by general formula (1) and n = 380 to 1500)
*11) Polyflow No. 90 (manufactured by Kyoeisha Chemical Co., Ltd.)
*12) N-770 (manufactured by DIC Corporation, phenol-novolac type epoxy resin, softening point 65-75°C, epoxy equivalent 188)
*13) YX-4000 (manufactured by Mitsubishi Chemical Corporation, biphenyl type epoxy resin, melting point 105°C, epoxy equivalent 190)
*14) SO-C2 (manufactured by Admatechs Co., Ltd., spherical silica, average particle size 0.45 to 0.65 μm)
*15) B-30 (manufactured by Sakai Chemical Industry Co., Ltd., barium sulfate)
*16) DPHA (dipentaerythritol hexaacrylate)

As is clear from the evaluation results shown in the above table, in each example, even if the coating was performed by the roll coating method, no air bubbles were observed on the coating film surface or inside the coating film, and the coating film had a good surface condition. It was confirmed that the resulting curable resin composition was obtained. In addition, since no air bubbles were observed on the surface of the coating film and inside the coating film, the insulation was also good.

Claims (3)

(A) a carboxyl group-containing resin,
(B) a photoinitiator,
(C) an organic solvent; and (D) a surface conditioner, comprising:
The (D) surface conditioner comprises (D-1) a modified polydimethylsiloxane obtained by organically modifying polydimethylsiloxane having n in the following general formula (1) in the range of 2 to 27, and (D-2 ) Contains modified polydimethylsiloxane obtained by organically modifying polydimethylsiloxane in which n in the following general formula (1) is in the range of 45 to 230 ,
For roll coating , wherein the compounding ratio of the surface conditioners (D-1) and (D-2) is (D-1):(D-2)=1:4 to 4:1 . A curable resin composition.

A cured product obtained by curing the curable resin composition according to claim 1 . A printed wiring board comprising the cured product according to claim 2 .