JP2021051263A - Curable resin composition, dry film, cured product, and electronic component - Google Patents

Abstract

To provide a curable resin composition that has excellent developability without delamination and other failure in resolution and thin film deposition and gives a cured product having excellent HAST resistance and crack resistance, a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, and an electronic component having the cured product.SOLUTION: A curable resin composition contains (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, and (C) an inorganic filler, the (C) inorganic filler having a particle size distribution that satisfies the following conditions (1)-(3): (1) D50 particle size value=1.0 μm or less; (2) (D90 particle size value)/(D10 particle size value)=5.0 or less; (3) ((D90 particle size value)-(D50 particle size value))/((D50 particle size value)-(D10 particle size value))=0.5-5.0.SELECTED DRAWING: Figure 1

Description

The present invention relates to curable resin compositions, dry films, cured products, and electronic components.

In recent years, the density of semiconductor packages has been increasing due to the high performance of electronic devices. Due to the demand for such high density, the pattern is required to be miniaturized in the insulating cured product layer such as solder resist.

On the other hand, in the method of manufacturing a wiring board in which a part of the connection pad is exposed from the solder resist layer, the solder resist layer is once thinned by exposing and developing in a range where the connection pad is not exposed, and then further exposed. , A manufacturing method for developing and exposing a part of a connection pad is known (Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-006809

In order to improve the resolution of the resin composition for the purpose of miniaturizing the pattern, it is conceivable to reduce the amount of the inorganic filler contained in the resin composition. In that case, HAST resistance, crack resistance, etc. It becomes difficult to obtain the desired effect by blending the inorganic filler.
Therefore, as in the manufacturing method described in Patent Document 1, the present inventors temporarily develop only the upper part of the connection pad to form a thin film, and then expose and develop it into a fine pattern, which is caused by the film thickness. It was examined to suppress the deterioration of resolution due to halation. By using this step, high resolution can be obtained on the connection pad, and reliability can be ensured in other parts.
However, it is difficult to control the development for thinning the film, and there are problems such as delamination of the unexposed portion and the exposed portion, reattachment, and poor tackiness of the unexposed portion. Deflection or reattachment of unexposed areas or exposed areas may cause problems such as poor connection reliability and poor appearance. Poor tackiness of unexposed areas may cause poor appearance due to scratches during transportation, exposure equipment, etc. May cause contamination.

Therefore, an object of the present invention is a curable resin composition obtained from a curable resin composition capable of obtaining a cured product having excellent developability without problems such as delamination in resolution and thin film formation, and also having excellent HAST resistance and crack resistance. It is an object of the present invention to provide a dry film having a resin layer, the composition or a cured product of the resin layer of the dry film, and an electronic component having the cured product.

As a result of diligent studies toward the realization of the above object, the present inventors have found that the above problems can be solved by blending an inorganic filler having a specific particle size distribution, and have completed the present invention.

That is, the curable resin composition of the present invention is a curable resin composition containing (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, and (C) an inorganic filler. ) The particle size distribution of the inorganic filler is characterized by satisfying the following conditions (1) to (3).
(1) D50 particle size value = 1.0 μm or less (2) (D90 particle size value) / (D10 particle size value) = 5.0 or less (3) ((D90 particle size value)-(D50 particle size value) ) / ((D50 particle size value)-(D10 particle size value)) = 0.5 to 5.0

In the curable resin composition of the present invention, it is preferable that the particle size distribution of the inorganic filler (C) further satisfies the following condition (4).
(4) D50 frequency = 7.0% or more

The curable resin composition of the present invention is preferably used in a method for producing a cured product, which comprises a step of partially thinning a resin layer made of the curable resin composition with a developing solution.

The curable resin composition of the present invention preferably has the content of the inorganic filler (C) of 25 to 70% by mass based on the total amount of the curable resin composition excluding the solvent.

The dry film of the present invention is characterized by having a resin layer obtained by applying the curable resin composition on the film and drying it.

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

The electronic component of the present invention is characterized by having the cured product.

According to the present invention, a curable resin composition capable of obtaining a cured product having excellent developability without problems such as delamination in resolution and thin film formation and excellent HAST resistance and crack resistance, and a resin obtained from the composition. A dry film having a layer, a cured product of the composition or a resin layer of the dry film, and an electronic component having the cured product can be provided.

FIG. 5 is a schematic cross-sectional view schematically showing an embodiment of a method of forming a pattern of a cured product by pattern exposure and development after thinning a resin layer made of a curable resin composition with a developing solution. FIG. 5 is a schematic cross-sectional view schematically showing an embodiment of a conventional method of forming a pattern of a cured product by pattern exposure and development of a resin layer made of a curable resin composition without thinning the film.

The curable resin composition of the present invention is a curable resin composition containing (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, and (C) an inorganic filler, and the above-mentioned (C) inorganic. The particle size distribution of the filler is characterized by satisfying the following conditions (1) to (3). (C) When the particle size distribution of the inorganic filler satisfies the following conditions (1) to (3), curing is excellent in resolution and thin film formation without problems such as delamination, and also in excellent HAST resistance and crack resistance. You can get things.
(1) D50 particle size value = 1.0 μm or less (2) (D90 particle size value) / (D10 particle size value) = 5.0 or less (3) ((D90 particle size value)-(D50 particle size value) ) / ((D50 particle size value)-(D10 particle size value)) = 0.5 to 5.0

In the present invention, the particle size distribution of (C) the inorganic filler is a particle size distribution including not only the particle size of the primary particles but also the particle size of the secondary particles (aggregates), and is a volume distribution measured by the laser diffraction method. is there. Examples of the measuring device by the laser diffraction method include the Microtrac MT3300EXII manufactured by Microtrac Bell. The D50 frequency is determined from the cumulative volume ratio occupied by each particle size obtained by the above measuring device, and can be obtained, for example, with a measurement range of 0.8 nm to 2000 μm and a channel (Ch) number of 50 to 132. This is the frequency of particle size at which the cumulative volume ratio is 50%.

The condition (1) (that is, the D50 particle size value) is preferably 0.8 μm or less, more preferably 0.5 μm or less, from the viewpoint of developability control, resolvability and melt viscosity at 40 ° C. The lower limit is not particularly limited, and is, for example, 0.1 μm or more, more preferably 0.2 μm or more from the viewpoint of developability control and the melt viscosity at 90 ° C. described later.
Condition (2) (that is, (D90 particle size value) / (D10 particle size value)) is preferably 3.0 to 4.5 from the viewpoint of the balance between the melt viscosity and the resolution at 40 ° C. and 90 ° C. Is.
Condition (3) (that is, ((D90 particle size value)-(D50 particle size value)) / ((D50 particle size value)-(D10 particle size value))) has a melt viscosity of 40 ° C. and 90 ° C. From the viewpoint of the balance of resolution, it is preferably 0.8 to 4.5, more preferably 1.5 to 4.0.

Condition (4) (that is, D50 frequency) is preferably 7.0% or more, more preferably 8.0% or more, from the viewpoint of the balance between the melt viscosity and the resolution at 40 ° C. and 90 ° C. Even more preferably, it is 9.0% or more.

Further, since the curable resin composition of the present invention is more excellent in tackiness, the melt viscosity at 40 ° C. ^{is preferably 1.0 × 10 4} dPa · s or more, and 8.0 × 10 ⁵ dPa. -It is more preferable that it is s or more. For example, (1) When the D50 particle size value is 0.6 μm or less and the blending amount of the inorganic filler is 40% by mass or more based on the total amount of the curable resin composition excluding the solvent, melting at 40 ° C. It has excellent developability control and resolution while increasing the viscosity. On the other hand, from the viewpoint of embedding in a fine circuit pattern, the melt viscosity at 90 ° C. ^{is preferably less than 1.0 × 10 3} dPa · s, and preferably 5.0 × 10 ¹ dPa · s or less. More preferred. For example, (1) When the D50 particle size value is 0.2 μm or more and the blending amount of the inorganic filler is 60% by mass or less based on the total amount of the curable resin composition excluding the solvent, melting at 90 ° C. It has excellent developability control and resolution while keeping the viscosity low.

The curable resin composition of the present invention can be suitably used in a method for producing a cured product, which comprises a step of partially thinning the film with a developing solution. For example, as shown in FIG. 1, after the resin layer 3 made of the curable resin composition is formed on the substrate 1 on which the conductor circuit 2 is formed (FIG. 1 (1)), the resin layer 3 is formed via the first negative mask 4. Partially exposed and the exposed portion is cured (FIG. 1 (2)). After that, development is performed in a time shorter than the breakpoint (shortest development time), and the resin layer is partially thinned, that is, only the upper part of the connection pad is thinned (FIG. 1 (3)). By exposing the thin film with a fine pattern via the negative mask 5 (FIG. 1 (4)) and then developing the thin film, a pattern of a cured product having excellent resolution can be formed on the connection pad. (Fig. 1 (5)). When trying to form a pattern of a cured product on the connection pad without going through the thinning step with respect to the resin layer on the substrate as in the conventional case (Fig. 2 (1)), the opening is scooped out by halation. Since it occurs (FIG. 2 (2)), it is difficult to form a pattern having excellent resolution. Further, by partially thinning the film with a developing solution, the reliability of the fine wiring portion is improved as compared with the case where the resin layer on the substrate is formed of a thin film dry film as in the conventional case.

Hereinafter, each component of the curable resin composition of the present invention will be described. In addition, in this specification, (meth) acrylate is a generic term for acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

[(A) Carboxyl group-containing resin]
As the carboxyl group-containing resin, various conventionally known 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 bond is preferably derived from acrylic acid or methacrylic acid or a derivative thereof. When only a carboxyl group-containing resin having no ethylenically unsaturated double bond is used, in order to make the composition photocurable, a compound having a plurality of ethylenically unsaturated groups in the molecule described later, that is, light It is necessary to use a reactive monomer together.
Specific examples of the carboxyl group-containing resin include the following compounds (either oligomer or polymer).

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

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

(3) Aliphatic compounds such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates, and polycarbonate-based polyols, polyether-based polyols, polyester-based polyols, polyolefin-based polyols, acrylic-based polyols, and bisphenol A-based A terminal carboxyl group-containing urethane resin obtained by reacting an acid anhydride at the end of a urethane resin by a double addition 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 ( Meta) A carboxyl group-containing photosensitive urethane resin obtained by a double addition reaction of an acrylate or a modified partial acid anhydride thereof, a carboxyl group-containing dialcohol compound and a diol compound.

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

(6) During the synthesis of the resin according to (2) or (4), one isocyanate group and one or more (meth) acryloyl groups are formed in the molecule, such as an isophorone diisocyanate and pentaerythritol triacrylate isomorphic reaction product. A carboxyl group-containing photosensitive urethane resin that is terminally (meth) acrylicized by adding the compound to be possessed.

(7) A carboxyl group-containing photosensitive resin obtained by reacting a bifunctional or higher polyfunctional (solid) epoxy resin with (meth) acrylic acid and adding a dibasic acid anhydride to a hydroxyl group existing in a side chain.

(8) 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 generated hydroxyl group. Group-containing photosensitive resin.

(9) A dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid is reacted with a bifunctional oxetane resin, and the generated primary hydroxyl group is subjected to two bases such as phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride. Carboxyl group-containing polyester resin to which acid anhydride is added.

(10) 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, and (meth). Reacting with an unsaturated group-containing monocarboxylic acid such as acrylic acid, maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipine with respect to the alcoholic hydroxyl group of the obtained reaction product. A carboxyl group-containing resin obtained by reacting a polybasic anhydride such as an acid.

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

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

(13) A carboxyl group-containing resin having at least one of an amide structure and an imide structure.

(14) 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 (1) to (13).

The carboxyl group-containing resin (A) is not limited to those listed above, and one type may be used alone or two or more types may be used in combination.

The acid value of the carboxyl group-containing resin (A) is preferably 20 to 200 mgKOH / g. When the acid value of the carboxyl group-containing resin (A) is 20 to 200 mgKOH / g, the pattern of the cured product can be easily formed. More preferably, it is 50 to 130 mgKOH / g.

The weight average molecular weight of the (A) carboxyl group-containing resin varies depending on the resin skeleton, but is generally preferably in the range of 2,000 to 150,000, more preferably 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 portion 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 portion is good, the resolution is excellent, and the storage stability may be improved. The weight average molecular weight can be measured by gel permeation chromatography.

The blending amount of the carboxyl group-containing resin (A) is, for example, 5 to 50% by mass, preferably 10 to 40% by mass, based on the total amount of the curable resin composition excluding the solvent. The coating film strength can be improved by setting the content to 5% by mass or more, preferably 10% by mass or more. Further, by setting it to 50% by mass or less, preferably 40% by mass or less, the viscosity becomes appropriate and the workability is improved.

[(B) Photopolymerization Initiator]
As the photopolymerization initiator (B), any photopolymerization initiator known as a photopolymerization initiator or a photoradical generator can be used, and for example, bis- (2,6-dichlorobenzoyl) can be used. ) 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 Bisacylphosphine oxides such as oxides, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; 2 , 6-Dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphos Monoacylphosphine oxides such as isopropyl phosphate, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 1-hydroxy-cyclohexylphenylketone, 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-propane- Hydroxyacetophenones such as 1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n -Benzoyls such as butyl ether; Benzoyl alkyl ethers; Benzoyls such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone; acetophenone, 2,2 − Dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 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; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethyl Thioxanthons such as thioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylantraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, Anthracinones such as 2-aminoanthraquinone; Ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2- (dimethylamino) ethyl benzoate and p-dimethylbenzoic acid ethyl ester Classes; 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole -3-Il]-, Oxime esters such as 1- (O-acetyloxime); bis (η5-2,4-cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-) Pyrrole-1-yl) phenyl) titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3- (2- (1-pyll-1-yl) ethyl) phenyl] titanocene such as titanium; Examples thereof include phenyldisulfide 2-nitrofluorene, butyloin, anisoine ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide and the like. (B) As the photopolymerization initiator, one type may be used alone, or two or more types may be used in combination.

The blending amount of the (B) photopolymerization initiator is preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the (A) carboxyl group-containing resin. When it is 0.5 parts by mass or more, the surface curability is good, and when it is 20 parts by mass or less, halation is less likely to occur and better resolution can be obtained.

[(C) Inorganic filler]
The inorganic filler (C) is not particularly limited as long as the above conditions (1) to (3) are satisfied, and known and commonly used fillers such as amorphous silica, crystalline silica, fused silica, spherical silica and the like, Neuburg Silica, aluminum hydroxide, glass powder, talc, clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica, aluminum oxide, barium sulfate, barium titanate, iron oxide, non-fibrous glass, hydrotalcite, mineral wool , Aluminum silicate, calcium silicate, zinc flower and other inorganic fillers can be used. Of these, silica is preferable, and spherical silica is more preferable because it has a small surface area and stress is dispersed throughout, so that it is unlikely to be the starting point of cracks.

The inorganic filler (C) may be subjected to a photoreactive surface treatment so as to have a vinyl group, a styryl group, a methacrylic group, an acrylic group or the like as a photocurable reactive group. In this case, the methacrylic group or acrylic may be treated. A group and a vinyl group are particularly preferable. Further, as the thermosetting reactive group, a hydroxyl group, a carboxyl group, an isocyanate group, an amino group, an imino group, an epoxy group, an oxetanyl group, a mercapto group, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group and an oxazoline group. The surface treatment may be thermally reactive so as to have the above, and in this case, an amino group and an epoxy group are particularly preferable. Furthermore, the (C) inorganic filler may have two or more curable reactive groups. As the inorganic filler (C), surface-treated silica is preferable. By including surface-treated silica, TCT resistance can be improved.

(C) The introduction method when introducing the curable reactive group onto the surface of the inorganic filler is not particularly limited, and it may be introduced by using a known and commonly used method, and a surface treatment agent having a curable reactive group, for example, curing The surface of the inorganic filler may be treated with a coupling agent or the like having a sex reactive group.

As the surface treatment of the inorganic filler (C), a surface treatment with a coupling agent is preferable. As the coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent and the like can be used. Of these, a silane coupling agent is preferable.

As the silane coupling agent, a silane coupling agent capable of introducing a curing reactive group into the (C) inorganic filler is preferable. Examples of the silane coupling agent into which a thermosetting reactive group can be introduced include a silane coupling agent having an epoxy group, a silane coupling agent having an amino group, a silane coupling agent having a mercapto group, and a silane coupling agent having an isocyanate group. Agents are mentioned, and among them, a silane coupling agent having an epoxy group is more preferable. Examples of the silane coupling agent into which a photocurable reactive group can be introduced include a silane coupling agent having a vinyl group, a silane coupling agent having a styryl group, a silane coupling agent having a methacryl group, and a silane coupling agent having an acrylic group. Agents are preferred, with silane coupling agents having a methacryl group being more preferred.

When the (C) inorganic filler is surface-treated, it is sufficient that the inorganic filler is blended in the curable resin composition of the present invention in the surface-treated state, and the surface-untreated (C) inorganic filler and the surface treatment agent are separately separated. Although the (C) inorganic filler may be surface-treated in the composition by blending, it is preferable to blend the (C) inorganic filler which has been surface-treated in advance. By blending the (C) inorganic filler that has been surface-treated in advance, it is possible to prevent deterioration of crack resistance and the like due to the surface treatment agent that may remain when the inorganic filler is blended separately and is not consumed in the surface treatment. In the case of surface treatment in advance, it is preferable to mix a pre-dispersion liquid in which (C) an inorganic filler is pre-dispersed in a solvent or a resin component, and the surface-treated (C) inorganic filler is pre-dispersed in a solvent and the pre-dispersion liquid is prepared. Is sufficiently surface-treated when pre-dispersing the surface-untreated (C) inorganic filler in a solvent, and then the pre-dispersion solution is blended into the composition.

(C) The method for preparing the particle size distribution of the inorganic filler is not particularly limited, and any method may be used as long as it can be dispersed so as to satisfy the above conditions (1) to (3). For example, using a bead mill, a locking mill, a jet mill, or the like, dispersion is performed at a rotation speed of 500 rpm or more, a pump output of 10% or more, and a dispersion temperature of 40 ° C. or more.

The blending amount of the inorganic filler (C) is preferably 25 to 70% by mass, more preferably 30 to 60% by mass, based on the total amount of the curable resin composition excluding the solvent.

(Thermosetting resin)
When a thermosetting resin is contained, the heat resistance of the cured product is improved, and the adhesion to the substrate is improved. As the thermosetting resin, known and commonly used thermosetting resins such as isocyanate compounds, blocked isocyanate compounds, amino resins, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy compounds, polyfunctional oxetane compounds, and episulfide resins can be used. .. Among these, epoxy compounds, polyfunctional oxetane compounds, and compounds having two or more thioether groups in the molecule, that is, episulfide resins are preferable, and epoxy compounds are more preferable. As the thermosetting resin, one type may be used alone or two or more types may be used in combination.

The epoxy compound is a compound having an epoxy group, and any conventionally known compound can be used. Examples thereof include a polyfunctional epoxy compound having a plurality of epoxy groups in the molecule. It may be a hydrogenated epoxy compound.

Examples of the polyfunctional epoxy compound include epoxidized vegetable oil; bisphenol A type epoxy resin; hydroquinone type epoxy resin; bisphenol type epoxy resin; thioether type epoxy resin; brominated epoxy resin; novolac type epoxy resin; biphenol novolac type epoxy resin; bisphenol F. Type epoxy resin; hydrogenated bisphenol A type epoxy resin; glycidylamine type epoxy resin; hydrantin type epoxy resin; alicyclic epoxy resin; trihydroxyphenylmethane type epoxy resin; bixyleneol type or biphenol type epoxy resin or a mixture thereof; Bisphenol S type epoxy resin; Bisphenol A novolac type epoxy resin; Tetraphenylol ethane type epoxy resin; Heterocyclic epoxy resin; Diglycidyl phthalate resin; Tetraglycidyl xylenoyl ethane resin; Naphthalene group-containing epoxy resin; Dicyclopentadiene skeleton Epoxy resin having glycidyl methacrylate copolymer; epoxy resin copolymerized with cyclohexyl maleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivative; CTBN-modified epoxy resin and the like, but are not limited thereto. .. These epoxy resins may be used alone or in combination of two or more.

Examples of the polyfunctional oxetane compound include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, and 1,4-bis [(3-3-oxythenylmethoxy) methyl] ether. Methyl-3-oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-3- Oxetane) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and polyfunctional oxetane such as their oligomers or copolymers, as well as oxetane alcohols and novolak resins. , Poly (p-hydroxystyrene), cardo-type bisphenols, calix arrayes, calix resorcinarenes, etherified compounds with a resin having a hydroxyl group such as silsesquioxane, and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate can also be mentioned.

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

Examples of amino resins such as melamine derivatives and benzoguanamine derivatives include methylol melamine compounds, methylol benzoguanamine compounds, methylol glycol uryl compounds and methylol urea compounds.

As the isocyanate compound, a polyisocyanate compound can be blended. Polyisocyanate compounds include 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate and Aromatic polyisocyanates such as 2,4-tolyrene isocyanate dimer; aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis (cyclohexylisocyanate) and isophorone diisocyanate; Alicyclic polyisocyanates such as bicycloheptanetriisocyanate; and adducts, burettes, and isocyanurates of the isocyanate compounds mentioned above can be mentioned.

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

The blending amount of the thermosetting resin is preferably 10 to 100 parts by mass with respect to 100 parts by mass of the (A) carboxyl group-containing resin. In particular, the blending amount of the thermosetting resin having two or more cyclic (thio) ether groups in the molecule is the amount of the (E) thermosetting resin with respect to one equivalent of the carboxyl group of the (A) carboxyl group-containing resin. The cyclic (thio) ether group contained is preferably in the range of 0.6 to 2.5 equivalents.

(Compound with ethylenically unsaturated bond)
The curable resin composition of the present invention may contain a compound having an ethylenically unsaturated bond, such as a photopolymerizable oligomer or a photopolymerizable vinyl monomer.

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

As the photopolymerizable vinyl monomer, known and commonly used ones, for example, styrene derivatives such as styrene, chlorostyrene, α-methylstyrene; vinyl esters such as vinyl acetate, vinyl butyrate or vinyl benzoate; vinyl isobutyl ether, vinyl- Vinyl ethers such as n-butyl ether, vinyl-t-butyl ether, vinyl-n-amyl ether, vinyl isoamyl ether, vinyl-n-octadecyl ether, vinyl cyclohexyl ether, ethylene glycol monobutyl vinyl ether, triethylene glycol monomethyl vinyl ether; acrylamide, (Meta) acrylamides such as methacrylicamide, N-hydroxymethylacrylamide, N-hydroxymethylmethacrylicamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-butoxymethylacrylamide; triallyl isocyanurate, diallyl phthalate, Allyl compounds such as diallyl isophthalate; 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tetrahydrofurfreel (meth) acrylate, isobolonyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, etc. (Meta) acrylic acid esters; hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate; methoxyethyl (meth) acrylate, ethoxyethyl Alkoxyalkylene glycol mono (meth) acrylates such as (meth) acrylate; ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di ( Alkylene polyol poly (meth) acrylates such as meta) acrylate, trimethylolpropantri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate; diethylene glycol di (meth) acrylate, triethylene glycol di. Polyoxyalkylene glycol poly (meth) acrylates, ethoxylated trimetylolpropan triacrylates, propoxylated trimethylol propantri (meth) acrylates, etc. Ta) Acrylate; Poly (meth) acrylates such as neopentyl glycol hydroxypylate di (meth) acrylate; Isocyanurate-type poly (meth) acrylates such as tris [(meth) acryloxyethyl] isocyanurate Can be mentioned. These may be used individually by 1 type or in combination of 2 or more type according to the required characteristics.

The blending amount of the compound having an ethylenically unsaturated bond is preferably 3 to 40 parts by mass with respect to 100 parts by mass of the (A) carboxyl group-containing resin. When it is 3 parts by mass or more, the surface curability is improved, and when it is 40 parts by mass or less, halation is suppressed. More preferably, it is 5 to 30 parts by mass.

(Thermosetting catalyst)
The curable resin composition of the present invention preferably contains a thermosetting catalyst. Examples of such a thermocuring catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole. , 1- (2-Cyanoethyl) -2-ethyl-4-methylimidazole and other imidazole derivatives; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N Examples thereof include amine compounds such as -dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. In addition, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine-isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine-isocyanulic acid adduct can also be used, preferably as these adhesion-imparting agents. A compound that also functions is used in combination with a thermosetting catalyst. One type of thermosetting catalyst may be used alone, or two or more types may be used in combination.

The blending amount of the thermosetting catalyst is preferably 0.5 to 10 parts by mass, more preferably 1.0 to 5 parts by mass with respect to 100 parts by mass of the (A) carboxyl group-containing resin. When it is 0.5 parts by mass or more, the reliability is improved, and when it is 10 parts by mass or less, outgas can be suppressed.

(Colorant)
The curable resin composition of the present invention may contain a colorant. As the colorant, known colorants such as red, blue, green, yellow, black, and white can be used, and any of pigments, dyes, and pigments may be used. However, it is preferable not to contain halogen from the viewpoint of reducing the environmental load and affecting the human body. One type of colorant may be used alone, or two or more types may be used in combination.

The amount of the colorant added is not particularly limited, but is preferably 10 parts by mass or less, particularly preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the (A) carboxyl group-containing resin.

(Organic solvent)
The curable resin composition of the present invention may contain an organic solvent for the purpose of preparing the composition, adjusting the viscosity when applied to a substrate or a carrier film, and the like. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethyl benzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol and propylene glycol monomethyl ether. , Dipropylene glycol monomethyl ether, Dipropylene glycol diethyl ether, Diethylene glycol monomethyl ether acetate, Tripropylene glycol monomethyl ether and other glycol ethers; 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 are known. Conventional organic solvents can be used. These organic solvents can be used alone or in combination of two or more.

(Other optional ingredients)
Further, the curable resin composition of the present invention may contain other additives known and commonly used in the field of electronic materials. Other additives include thermal polymerization inhibitors, UV absorbers, curing agents, silane coupling agents, plasticizers, flame retardants, antistatic agents, antiaging agents, antibacterial / antifungal agents, defoaming agents, leveling agents. , Thickening agent, Adhesion imparting agent, Tixo property imparting agent, Photoinitiating aid, Sensitizer, Thermoplastic resin, Organic filler, Defoaming agent, Surface treatment agent, Dispersant, Dispersion aid, Surface modifier , Stabilizers, phosphors and the like.

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

Next, the dry film of the present invention has a resin layer obtained by applying and drying the curable resin composition of the present invention on a carrier film. When forming a dry film, first, the curable resin composition of the present invention is diluted with the above organic solvent to adjust the viscosity to an appropriate level, and then a comma coater, a blade coater, a lip coater, a rod coater, and a squeeze coater. , Reverse coater, transfer coater, gravure coater, spray coater, etc., and apply to a uniform thickness on the carrier film. Then, the applied composition is usually dried at a temperature of 40 to 130 ° C. for 1 to 30 minutes to form a resin layer. The coating film thickness is not particularly limited, but is generally selected as appropriate in the range of 3 to 150 μm, preferably 5 to 60 μm after drying.

As the carrier 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 the carrier film is not particularly limited, but is generally selected as appropriate in the range of 10 to 150 μm. More preferably, it is in the range of 15 to 130 μm.

After forming the resin layer made of the curable resin composition of the present invention on the carrier film, a peelable cover is further provided on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer. It is preferable to stack the films. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, surface-treated paper, or the like can be used. The cover film may be smaller than the adhesive force between the resin layer and the carrier film when the cover film is peeled off.

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

The electronic component of the present invention has a cured product obtained from the curable resin composition of the present invention or the resin layer of a dry film. As a method for producing an electronic component using the curable resin composition of the present invention, a conventionally known method may be used, but as described above, the resin layer made of the curable resin composition is partially thinned by a developing solution. The curable resin composition of the present invention can be preferably used in a production method including a step of converting. 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 a dip coating method, a flow coating method, a roll coating method, a bar coater method, etc. After coating by a method such as a screen printing method or a curtain coating method, a tack-free resin layer is formed by volatilizing and drying (temporarily drying) the organic solvent contained in the composition at a temperature of 60 to 100 ° C. Further, in the case of a dry film, a resin layer is formed on the base material by sticking the resin layer on the base material with a laminator or the like so that the resin layer comes into contact with the base material, and then peeling off the carrier film.

The base material includes a printed wiring board and a flexible printed wiring board whose circuit is formed of copper or the like in advance, as well as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, and glass cloth / paper epoxy. , Synthetic fiber epoxy, fluororesin / polyethylene / polyimideene ether, polyphenylene oxide / cyanate, etc. are used for high-frequency circuit copper-clad laminates, etc., and all grades (FR-4, etc.) of copper-clad laminates are used. Plates, other metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates and the like can be mentioned.

The volatile drying performed after applying the curable resin composition of the present invention is carried out in a hot air circulation type drying furnace, an IR furnace, a hot plate, a convection oven, etc. It can be carried out by using a method of bringing hot air into countercurrent contact and a method of blowing hot air onto a support from a nozzle).

After forming a resin layer on the printed wiring board, it is selectively exposed to active energy rays through a photomask having a predetermined pattern, and the unexposed portion is exposed to a dilute alkaline aqueous solution (for example, 0.3 to 3 mass% sodium carbonate aqueous solution). ), The resin layer is partially thinned by developing in a time shorter than the breakpoint (shortest development time). After forming the thin film, it is selectively exposed to active energy rays through a photomask having a predetermined pattern, and the unexposed portion is developed with a dilute alkaline aqueous solution (for example, 0.3 to 3 mass% sodium carbonate aqueous solution) to cure the cured product. Form the pattern of. Further, the cured product is adhered by irradiating the cured product with active energy rays and then heat curing (for example, 100 to 220 ° C.), or by irradiating the cured product with active energy rays after heat curing or by performing final finish curing (main curing) only by heat curing. It forms a cured film with excellent properties such as properties and hardness.
When the curable resin composition of the present invention contains a photobase generator, it is preferable to heat it after exposure and before development, and the heating conditions after exposure and before development are, for example, 1 to 1 at 60 to 150 ° C. It is preferable to heat for 60 minutes.

The exposure machine used for the above-mentioned active energy ray irradiation is a device equipped with a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc., and irradiates the active energy ray in the range of 350 to 450 nm. Often, a direct drawing device (eg, a laser direct imaging device that draws an image directly with a laser from CAD data from a computer) can also be used. The lamp light source or the 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 is generally 10 to 1000 mJ / cm ² , preferably 20 to 800 mJ / cm ² .

The developing method can be a dipping method, a shower method, a spray method, a brush method or the like, and the developing solution includes potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, etc. Alkaline aqueous solutions such as ammonia and amines can be used.

The curable resin composition of the present invention is suitably used for forming a cured film on a printed wiring board, more preferably used for forming a permanent film, and more preferably a solder resist. It is used to form an interlayer insulating layer and a coverlay. Further, according to the curable resin composition of the present invention, a cured product having excellent resolution, HAST resistance and TCT resistance can be obtained, so that a printed circuit board having a fine pitch wiring pattern that requires high reliability can be obtained. It can be suitably used for forming a wiring board, for example, a package substrate, particularly a permanent coating (particularly a solder resist) for FC-BGA.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples. In the following, "part" and "%" are all based on mass unless otherwise specified. The blending amount of each component described in the table is the mass part of the solid content containing no solvent.

[Synthesis of carboxyl group-containing resin]
(Synthesis Example 1: Carboxyl Group-Containing Resin (A) -1)
A flask equipped with a cooling tube and a stirrer was charged with 456 parts of bisphenol A, 228 parts of water, and 649 parts of 37% formalin, kept at a temperature of 40 ° C. or lower, and added 228 parts of a 25% sodium hydroxide aqueous solution. The reaction was carried out at ° C. for 10 hours. After completion of the reaction, the mixture was cooled to 40 ° C. and neutralized to pH 4 with a 37.5% aqueous phosphoric acid solution while maintaining 40 ° C. or lower. After that, it was allowed to stand and the aqueous layer was separated. After separation, 300 parts of methyl isobutyl ketone was added to uniformly dissolve the mixture, followed by washing with 500 parts of distilled water three times, and the water, solvent and the like were removed under reduced pressure at a temperature of 50 ° C. or lower. The obtained polymethylol compound was dissolved in 550 parts of methanol to obtain 1230 parts of a methanol solution of the polymethylol compound.
When a part of the obtained methanol solution of the polymethylol compound was dried in a vacuum dryer at room temperature, the solid content was 55.2%.
In a flask equipped with a cooling tube and a stirrer, 500 parts of a methanol solution of the obtained polymethylol compound and 440 parts of 2,6-xylenol were charged and dissolved uniformly at 50 ° C. After uniformly dissolving, methanol was removed under reduced pressure at a temperature of 50 ° C. or lower. Then, 8 parts of oxalic acid was added, and the reaction was carried out at 100 ° C. for 10 hours. After completion of the reaction, the distillate was removed at 180 ° C. under a reduced pressure of 50 mmHg to obtain 550 parts of novolak resin A.
In an autoclave equipped with a thermometer, a nitrogen introduction device and an alkylene oxide introduction device, and a stirring device, 130 parts of Novolak resin A, 2.6 parts of a 50% sodium hydroxide aqueous solution, and toluene / methyl isobutyl ketone (mass ratio = 2/1). 100 parts were charged, the inside of the system was replaced with nitrogen while stirring, then the temperature was raised by heating, and 60 parts of propylene oxide was gradually introduced at ^{150 ° C. and 8 kg / cm 2 to react.} The reaction was continued for about 4 hours until the gauge pressure reached 0.0 kg / cm ^{2, and then cooled to room temperature.} 3.3 parts of a 36% aqueous hydrochloric acid solution was added to and mixed with this reaction solution to neutralize sodium hydroxide. The neutralization reaction product was diluted with toluene, washed with water three times, and desolvated with an evaporator to have a hydroxyl value of 189 g / eq. A propylene oxide adduct of novolak resin A was obtained. This was an average addition of 1 mol of propylene oxide per equivalent of phenolic hydroxyl group.
189 parts of the obtained novolak resin A propylene oxide adduct, 36 parts of acrylic acid, 3.0 parts of p-toluenesulfonic acid, 0.1 part of hydroquinone monomethyl ether, and 140 parts of toluene were mixed with a stirrer, a thermometer, and an air blowing tube. The mixture was charged into a reactor equipped with the above, stirred while blowing air, heated to 115 ° C., and the water produced by the reaction was distilled off as an azeotropic mixture with toluene to react for another 4 hours, and then to room temperature. Cooled. The obtained reaction solution was washed with water using a 5% NaCl aqueous solution, toluene was removed by distillation under reduced pressure, and then diethylene glycol monoethyl ether acetate was added to obtain an acrylate resin solution having a solid content of 67%.
Next, 322 parts of the obtained acrylate resin solution, 0.1 part of hydroquinone monomethyl ether, and 0.3 part of triphenylphosphine were charged into a four-necked flask equipped with a stirrer and a reflux condenser, and the mixture was charged at 110 ° C. To, 60 parts of tetrahydrophthalic anhydride was added, the mixture was reacted for 4 hours, cooled, and then taken out. The solution of the photosensitive carboxyl group-containing resin (A) -1 thus obtained had a solid content of 70% and a solid content acid value of 81 mgKOH / g. Hereinafter, this solution of the carboxyl group-containing resin is referred to as a resin solution (A) -1.

(Synthesis Example 2: Carboxyl Group-Containing Resin (A) -2)
In an autoclave equipped with a thermometer, a nitrogen introduction device and an alkylene oxide introduction device, and a stirring device, 119.4 parts of a novolak type cresol resin (Shonol CRG951 manufactured by Showa Denko Co., Ltd., OH equivalent: 119.4), potassium hydroxide 1. 19 parts and 119.4 parts of toluene were introduced, the inside of the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 parts of propylene oxide was gradually added dropwise, and the mixture was reacted at ^{125 to 132 ° C. and 0 to 4.8 kg / cm 2 for 16 hours.} Then, the mixture was cooled to room temperature, and 1.56 parts of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide. The non-volatile content was 62.1% and the hydroxyl value was 182.2 mgKOH / g (307. A propylene oxide reaction solution of a novolak-type cresol resin at 9 g / eq.) Was obtained. This was an average of 1.08 mol of propylene oxide added per equivalent of phenolic hydroxyl group.
293.0 parts of propylene oxide reaction solution of the obtained novolak type cresol resin, 43.2 parts of acrylic acid, 11.53 parts of methanesulfonic acid, 0.18 parts of methylhydroquinone and 252.9 parts of toluene were mixed with a stirrer and temperature. It was introduced into a reactor equipped with a meter and an air blowing tube, and air was blown at a rate of 10 ml / min and reacted at 110 ° C. for 12 hours with stirring. As for the water produced by the reaction, 12.6 parts of water was distilled off as an azeotropic mixture with toluene. Then, the mixture was cooled to room temperature, and the obtained reaction solution was neutralized with 35.35 parts of a 15% aqueous sodium hydroxide solution, and then washed with water. Then, toluene was distilled off while substituting 118.1 parts of diethylene glycol monoethyl ether acetate with an evaporator to obtain a novolak type acrylate resin solution. Next, 332.5 parts of the obtained novolak type acrylate resin solution and 1.22 parts of triphenylphosphine were introduced into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was introduced at a rate of 10 ml / min. With stirring, 60.8 parts of tetrahydrophthalic anhydride was gradually added, reacted at 95 to 101 ° C. for 6 hours, cooled, and then taken out. In this way, a solution of the photosensitive carboxyl group-containing resin (A) -2 having a solid content of 65% and an acid value of 87.7 mgKOH / g as a solid content was obtained. Hereinafter, this solution of the carboxyl group-containing resin is referred to as a resin solution (A) -2.

(Synthesis Example 3: Carboxyl Group-Containing Resin (A) -3)
600 g of diethylene glycol monoethyl ether acetate and 1070 g of orthocresol novolac type epoxy resin (EPICLON N-695 manufactured by DIC, softening point 95 ° C., epoxy equivalent 214, average number of functional groups 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 and heated and stirred at 100 ° C. to uniformly dissolve.
Then, 4.3 g of triphenylphosphine was charged, heated to 110 ° C. for 2 hours, then heated to 120 ° C. and further reacted for 12 hours. To the obtained reaction solution, 415 g of aromatic hydrocarbon (Solbesso 150) and 456.0 g (3.0 mol) of tetrahydrophthalic anhydride were charged, reacted at 110 ° C. for 4 hours, cooled, and photosensitive carboxyl. A solution of the group-containing resin (A) -3 was obtained. The solid content of the resin solution thus obtained was 65%, and the acid value of the solid content was 89 mgKOH / g. Hereinafter, this solution of the carboxyl group-containing resin is referred to as a resin solution (A) -3.

[Preparation of inorganic filler]
(Adjustment Example 1: Inorganic Filler Slurry (C) -1)
50 g of spherical silica particles (Admafine SO-C3 manufactured by Admatex, average particle size: 800 nm), 48 g of PMA as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) are blended. Stir and carry out dispersion treatment with a bead mill (K-8 manufactured by BUHLER) at a rotation speed of 900 rpm, a pump output of 20%, and a dispersion temperature of 40 to 50 ° C., condition (1) is 0.8 μm, condition (2). Was 4.0, condition (3) was 2.0, and condition (4) was 11.5%. The obtained dispersion is designated as an inorganic filler slurry (C) -1. The particle size distributions (1) to (4) of the obtained inorganic fillers were obtained by using Microtrac MT3300EXII manufactured by Microtrac Bell, Inc., with a measurement range of 0.8 nm to 6.54 μm and a channel (Ch) number of 52. The values are as shown in the table below. The same applies to the other inorganic fillers used in Examples and Comparative Examples.

(Adjustment example 2: Inorganic filler slurry (C) -2)
50 g of spherical silica particles (Admafine SO-C2 manufactured by Admatex, average particle size: 500 nm), 48 g of PMA as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) are blended. Stir and carry out dispersion treatment with a bead mill (K-8 manufactured by BUHLER) at a rotation speed of 900 rpm, a pump output of 20%, and a dispersion temperature of 40 to 50 ° C., condition (1) is 0.5 μm, condition (2). Was 3.3, the condition (3) was 3.7, and the condition (4) was 8.7%. The obtained dispersion is designated as an inorganic filler slurry (C) -2.

(Adjustment Example 3: Inorganic Filler Slurry (C) -3)
50 g of spherical silica particles (Admafine SO-C1 manufactured by Admatex, average particle size: 300 nm), 48 g of PMA as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) are blended. Stir and carry out dispersion treatment with a bead mill (K-8 manufactured by BUHLER) at a rotation speed of 900 rpm, a pump output of 20%, and a dispersion temperature of 40 to 50 ° C., condition (1) is 0.3 μm, condition (2). Was 3.7, condition (3) was 1.7, and condition (4) was 9.5%. The obtained dispersion is designated as an inorganic filler slurry (C) -3.

(Adjustment Example 4: Inorganic Filler Slurry (C) -4)
50 g of spherical silica particles (Admatex 100 nm, average particle size: 100 nm), 48 g of PMA as a solvent, and 2 g of a silane coupling agent having a methacrylic group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed and stirred. Dispersion treatment was performed with a bead mill (K-8 manufactured by BUHLER) at a rotation speed of 900 rpm, a pump output of 20%, and a dispersion temperature of 40 to 50 ° C., and the condition (1) was 0.1 μm and the condition (2) was 4. 2. A dispersion was obtained in which condition (3) was 4.0 and condition (4) was 8.5%. The obtained dispersion is designated as an inorganic filler slurry (C) -4.

(Adjustment Example 5: Inorganic Filler Slurry (C) -5)
50 g of barium sulfate (B-33 manufactured by Sakai Chemical Co., Ltd.), 48 g of PMA as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) are mixed and stirred, and a bead mill (K manufactured by BUHLER) is mixed and stirred. In -8), the dispersion treatment was carried out at a rotation speed of 900 rpm, a pump output of 20%, and a dispersion temperature of 40 to 50 ° C., the condition (1) was 0.5 μm, the condition (2) was 4.0, and the condition (3). The dispersion was 2.0 and the condition (4) was 14.1%. The obtained dispersion is referred to as an inorganic filler slurry (C) -5.

(Adjustment Example 6: Inorganic Filler Slurry (R) -1)
50 g of spherical silica particles (Admafine SO-C4 manufactured by Admatex, average particle size: 1.2 μm), 48 g of PMA as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.). The dispersion treatment was carried out with a bead mill (K-8 manufactured by BUHLER) at a rotation speed of 900 rpm, a pump output of 20%, and a dispersion temperature of 40 to 50 ° C., and the condition (1) was 1.2 μm and the condition (1) was 1.2 μm. A dispersion was obtained in which 2) was 5.0, condition (3) was 3.8, and condition (4) was 7.2%. The obtained dispersion is designated as an inorganic filler slurry (R) -1.

(Adjustment Example 7: Inorganic Filler Slurry (R) -2)
Spherical silica particles A (Admatex Admanano 100 nm, average particle size: 100 nm) 10 g, spherical silica particles B (Admatex Admafine SO-C2, average particle size: 500 nm) 30 g, spherical silica particles (Admatex) Admafine SO-C4 manufactured by the company, average particle size: 1.2 μm) 10 g, PMA 48 g as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shinetsu Chemical Industry Co., Ltd.) are mixed and stirred, and a bead mill (bead mill The dispersion treatment was carried out with BUHLER K-8) at a rotation speed of 900 rpm, a pump output of 20%, and a dispersion temperature of 40 to 50 ° C., condition (1) was 0.5 μm, condition (2) was 9.0, A dispersion was obtained in which condition (3) was 4.5 and condition (4) was 5.5%. The obtained dispersion is designated as an inorganic filler slurry (R) -2.

(Adjustment Example 8: Inorganic Filler Slurry (R) -3)
50 g of spherical silica particles (Admafine SO-C2 manufactured by Admatex, average particle size: 500 nm), 48 g of PMA as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) are blended. After stirring, the dispersion treatment was carried out twice at a bead mill (K-8 manufactured by BUHLER) at a rotation speed of 1080 rpm, a pump output of 15%, and a dispersion temperature of 50 to 60 ° C., and the condition (1) was 0.5 μm and the condition (1) was 0.5 μm. A dispersion was obtained in which 2) was 4.8, condition (3) was 7.2, and condition (4) was 7.2%. The obtained dispersion is designated as an inorganic filler slurry (R) -3.

(Adjustment Example 9: Inorganic Filler Slurry (R) -4)
Spherical silica particles A (Admatex Admanano 100 nm, average particle size: 100 nm) 20 g, spherical silica particles B (Admatex Admafine SO-C2, average particle size: 500 nm) 10 g, spherical silica particles (Admatex) Admafine SO-C4 manufactured by the company, average particle size: 1.2 μm) 20 g, PMA 48 g as a solvent, and 2 g of a silane coupling agent having a methacrylic group (KBM-503 manufactured by Shinetsu Chemical Industry Co., Ltd.) are mixed and stirred, and a bead mill (bead mill (KBM-503) The dispersion treatment was carried out with BUHLER K-8) at a rotation speed of 900 rpm, a pump output of 20%, and a dispersion temperature of 40 to 50 ° C., condition (1) was 0.5 μm, condition (2) was 9.5, A dispersion was obtained in which condition (3) was 2.2 and condition (4) was 3.0%. The obtained dispersion is designated as an inorganic filler slurry (R) -4.

(Adjustment Example 10: Inorganic Filler Slurry (R) -5)
50 g of spherical silica particles (Admafine SO-C2 manufactured by Admatex, average particle size: 500 nm), 48 g of PMA as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) are blended. After stirring, dispersion treatment was carried out with a bead mill (K-8 manufactured by BUHLER) at a rotation speed of 300 rpm, a pump output of 30%, and a dispersion temperature of 30 to 40 ° C., and the condition (1) was 0.8 μm and the condition (2) was A dispersion of 3.8, condition (3) of 0.4, and condition (4) of 10.3% was obtained. The obtained dispersion is referred to as an inorganic filler slurry (R) -5.

[Examples 1 to 12, Comparative Examples 1 to 5]
The various components in the table were blended in the proportions (parts by mass) shown in the table, premixed with a stirrer, and then kneaded with a bead mill to prepare a curable resin composition.

<Procedure for manufacturing test dry film>
A curable resin composition was applied onto a PET film using a die coater to a desired thickness in each of Examples and Comparative Examples, and passed through a drying furnace at 60 to 120 ° C. at 5 to 15 m / min. By volatilizing the solvent, a dry film having a resin layer made of a curable resin composition was obtained.

<Procedures for forming, exposing, developing, and curing a resin layer made of a curable resin composition>
The dry film obtained by the above method was laminated on a test substrate using a vacuum laminator CVP-300 (manufactured by Nikko Materials Co., Ltd.), and a resin layer made of a curable resin composition was formed on the test substrate. This resin layer was exposed using DXP-3580 (manufactured by ORC, an ultra-high pressure mercury lamp DI exposure machine) with a Stuffer 41-step step tablet according to the evaluation items so that the number of curing steps was 10. The PET film was peeled off 10 minutes after the exposure, and development was carried out in a 1 wt% sodium carbonate aqueous solution at 30 ° C. with a development time twice the breakpoint (shortest development time). Then, the curable resin composition was cured by exposure at 2000 mJ on a UV conveyor (Metal halide lamp manufactured by ORC) and heating at 170 ° C. for 60 minutes in a heat circulation type Box furnace.

<Developability control>
The above resin layer is formed on a plated copper substrate treated with ^{CZ-8201B under the condition of an etching rate of 0.5 μm / m 2} using a dry film having a thickness of about 30 μm of the resin layer prepared as described above. -In the exposure procedure, a resin layer made of a curable resin composition was formed so as to have a film thickness of about 30 μm, and exposure was performed with a punching pattern of 30 mm × 30 mm. After peeling off the PET film, develop with a 1 wt% sodium carbonate aqueous solution at 30 ° C. at 1/2 and 2/3 times the breakpoint (shortest development time, that is, the shortest time for completely removing the unexposed area). Was done. The evaluation substrate obtained as described above was observed and evaluated.
◎… Good developability with no delamination or reattachment of exposed and unexposed areas under any conditions ○… When the breakpoint is set to 2/3 times (the film thickness is reduced to 2/3), the tackiness and development speed are improved. Although workability such as control is inferior, there is no delamination and reattachment in unexposed areas.
× ... When the break point is 2/3 times (the film thickness is reduced to 2/3), delamination and reattachment of the unexposed part occur.
XX ... Delamination and reattachment occur at a breakpoint of 1/2 times (the film thickness is halved).

<Resolution evaluation>
The above resin layer is formed on a plated copper substrate treated with ^{CZ-8201B under the condition of an etching rate of 0.5 μm / m 2} using a dry film having a thickness of about 15 μm of the resin layer prepared as described above. In the procedure, a resin layer made of a curable resin composition was formed so as to have a film thickness of about 15 μm, and exposure was performed with various opening patterns so that the number of curing steps was 10 and 12 with a Stuffer 41-step step tablet. Then, the development and curing were carried out by the above-mentioned developing and curing procedure of the resin layer.
By observing the opening diameter of the evaluation substrate obtained as described above, is it possible to form a good opening diameter with a Stoffer 41-step step tablet without occurrence of halation or undercut under any of the conditions of the number of curing steps of 10 and 12 steps? We confirmed and evaluated it.
◎… A good opening diameter can be obtained at 50 μm ○… A good opening diameter can be obtained at 60 μm ×… A good opening diameter can be obtained at 70 μm, but a good opening diameter cannot be obtained at 60 μm or less ×× ... A good opening diameter cannot be obtained at 70 μm.

<HAST resistance>
Using a dry film having a resin layer thickness of about 15 μm prepared as described above, a comb-shaped pattern of L / S = ^{8/8 μm treated with CZ-8201B under the condition of an etching rate of 0.5 μm / m 2 was obtained.} A resin layer made of a curable resin composition was formed on the formed substrate so as to have a thickness on copper of about 15 μm by the above procedure for forming and exposing the resin layer, and the entire surface was exposed. Then, the development and curing were carried out by the above-mentioned developing and curing procedure of the resin layer. Then, the electrodes were connected and the HAST test was carried out under the conditions of 130 ° C., 85% and 3.3 V.
⊚: 300h pass
◯: 250h pass, NG within 300h
Δ: 200h pass, NG within 250h
×: NG within 200 hours

<TCT resistance>
The above resin layer is formed on a package substrate treated with ^{CZ-8201B at an etching rate of 0.5 μm / m 2} using a dry film having a thickness of about 15 μm of the resin layer prepared as described above. In the exposure procedure, a resin layer made of a curable resin composition was formed so as to have a thickness of about 15 μm on Cu, and an opening diameter of 80 μm was exposed on a copper pad having a pitch of 170 μm. Then, the development and curing were carried out by the above-mentioned developing and curing procedure of the resin layer. Then, Au plating treatment, solder bump formation, and Si chip were mounted to obtain an evaluation substrate.
The evaluation substrate obtained as described above was placed in a thermal cycle machine in which a temperature cycle was performed between −65 ° C. and 150 ° C., and TCT (Thermal Cycle Test) was performed. Then, the surface of the cured film at 600 cycles, 800 cycles and 1000 cycles was observed. The judgment criteria are as follows.
⊚: No abnormality in 1000 cycles ○: No abnormality in 800 cycles, cracks in 1000 cycles Δ: No abnormality in 600 cycles, cracks in 800 cycles ×: Cracks in 600 cycles

<Melting viscosity>
Using the dry film having the thickness of the resin layer of about 20 μm prepared as described above, the resin layer made of the curable resin composition is dried a plurality of times on the copper foil substrate so that the film thickness of the resin layer is about 400 μm. The film was laminated.
The resin layer obtained as described above was peeled off from the copper foil and evaluated. The measurement was performed using a rheometer measuring device (model name: RS6000 manufactured by Hakke), and evaluation was performed at 40 ° C. and 90 ° C. The evaluation criteria are as follows.
・ ・ ・ 40 ℃ ・ ・ ・
◎… 8.0 × 10 ⁵ dPa · s or more ○… 1.0 × 10 ⁴ dPa · s or more 8.0 × 10 ⁵ less than dPa · s ×… 1.0 × 10 ⁴ less than dPa · s ・ ・ ・ 90 ℃ ・ ・ ・
◎… 5.0 × 10 ^{less than 1} dPa ・ s ○… 5.0 × 10 ¹ dPa ・ s or more 1.0 × 10 ³ less than 3 dPa ・ s ×… 1.0 × 10 ³ dPa ・ s or more

* 1: Carboxyl group-containing resin (A) -1 synthesized above
* 2: Carboxyl group-containing resin (A) -2 synthesized above
* 3: Carboxyl group-containing resin (A) -3 synthesized above
* 4: Omnirad TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide) manufactured by IGM Resins.
* 5: Omnirad 907 manufactured by IGM Resins (2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one)
* 6: BASF Japan's Irgacure OXE02 (Etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] -1- (o-acetyloxime)
* 7: Inorganic filler slurry (C) -1 prepared above
* 8: Inorganic filler slurry (C) -2 prepared above
* 9: Inorganic filler slurry (C) -3 prepared above
* 10: Inorganic filler slurry (C) -4 prepared above
* 11: Inorganic filler slurry (C) -5 prepared above
* 12: Inorganic filler slurry (R) -1 prepared above
* 13: Inorganic filler slurry (R) -2 prepared above
* 14: Inorganic filler slurry (R) -3 adjusted above
* 15: Inorganic filler slurry (R) -4 adjusted above
* 16: Inorganic filler slurry (R) -5 adjusted above
* 17: EPICLON N-770 manufactured by DIC (phenol novolac type epoxy resin, epoxy equivalent 185 g / eq.)
* 18: EPICLON N-740 manufactured by DIC (phenol novolac type epoxy resin, epoxy equivalent 180 g / eq.)
* 19: EPICLON N-730-A manufactured by DIC (phenol novolac type epoxy resin, epoxy equivalent 175 g / eq.)
* 20: DPHA (dipentaerythritol hexaacrylate) manufactured by Nippon Kayaku Co., Ltd.
* 21: Dicyanodiamide

From the results shown in the above table, the curable resin compositions of Examples 1 to 12 of the present invention are excellent in resolvability and developability without problems such as delamination in thin film formation, and are also excellent in HAST resistance and crack resistance. It can be seen that a cured product can be formed.

1 Substrate 2 Conductor circuit 3 Resin layer composed of curable resin composition 3a Resin layer in which the curable resin composition is partially cured 3b Resin layer in which the curable resin composition is cured 4 First negative mask 5 Second negative mask

Claims (7)

A curable resin composition containing a carboxyl group-containing resin, (B) a photopolymerization initiator, and (C) an inorganic filler.
A curable resin composition, wherein the particle size distribution of the inorganic filler (C) satisfies the following conditions (1) to (3).
(1) D50 particle size value = 1.0 μm or less (2) (D90 particle size value) / (D10 particle size value) = 5.0 or less (3) ((D90 particle size value)-(D50 particle size value) ) / ((D50 particle size value)-(D10 particle size value)) = 0.5 to 5.0 The curable resin composition according to claim 1, wherein the particle size distribution of the inorganic filler (C) further satisfies the following condition (4).
(4) D50 frequency = 7.0% or more The curable resin composition according to claim 1 or 2, wherein the resin layer made of the curable resin composition is used in a method for producing a cured product, which comprises a step of partially thinning the resin layer with a developing solution. The curable resin according to any one of claims 1 to 3, wherein the content of the inorganic filler (C) is 25 to 70% by mass based on the total amount of the curable resin composition excluding the solvent. Composition. A dry film having a resin layer obtained by applying the curable resin composition according to any one of claims 1 to 4 onto a film and drying the film. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 4 or the resin layer of the dry film according to claim 5. An electronic component comprising the cured product according to claim 6.

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