TW202004336A - Curable resin composition, dry film, cured product, and printed wiring board - Google Patents

Abstract

Provided are the following: a curable resin composition which exhibits excellent B-HAST resistance and PCT resistance while ensuring excellent reliability as a rigid cured product having excellent TCT resistance; and a dry film, a cured product and a printed wiring board obtained using the curable resin composition. The present invention is: a curable resin composition which contains (A) a carboxyl group-containing resin, (B) an epoxy resin having a dicyclopentadiene skeleton, (C) a photopolymerization initiator, and (D) spherical silica, with the content of the spherical silica (D) being 50 mass% or more relative to non-volatile components in the composition; and a dry film, a cured product and a printed wiring board obtained using the curable resin composition.

Description

Curable resin composition, dry film, cured product and printed wiring board

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

Conventionally, for a material formed by exposing and developing a permanent coating such as solder resist in a printed wiring board, a curable resin composition that can be developed with an aqueous alkali solution can be used. On the other hand, in response to the increase in density of printed wiring boards required for thinner, thinner and shorter electronic devices, miniaturization of semiconductor packages or high pin count systems have been put into practical use and mass production continues to progress. Recently, even the use of packaging Substrate semiconductor packages such as BGA (ball grid array) or CSP (chip scale package) instead of QFP (quad flat package) or SOP (Small outline package) semiconductor package. In such a package substrate, the wiring pattern is formed with higher density and closer to each other, so the permanent coating of the solder resist used in the package substrate requires high reliability (insulation reliability (B-HAST resistance), high temperature Humidification resistance (PCT resistance), cold and heat cycle resistance (TCT resistance), heat resistance, etc.).

For such a solder resist for a package substrate, in order to provide a method with high reliability, it is generally possible to improve the characteristics such as rigidity by implementing, for example, a high-fill inorganic filler in the curable resin composition. Among the inorganic fillers, particularly spherical silica has excellent filling properties and low coefficient of thermal expansion (CTE), and is widely used to increase the rigidity of solder resists or improve TCT resistance (refer to Patent Document 1). [Prior Technical Document of the Invention] [Patent Literature]

Patent Literature 1: JP 2014-81611

[Problems to be solved by the present invention]

However, if the inorganic filler such as spherical silica is highly filled in the curable resin composition, there is a new problem that the B-HAST resistance of the cured product or the PCT resistance deteriorates.

Here, the object of the present invention is to provide an inorganic filler such as spherical silica which is highly filled in a curable resin composition, which can not only ensure excellent reliability as a hardened product with high rigidity or excellent TCT resistance, Provides a curable resin composition excellent in B-HAST resistance and PCT resistance, a dry film, a cured product, and a printed wiring board using the same. [Means of the present invention to solve the problem]

The inventors focused on the spherical silica with high filling property and excellent properties, and studied and reviewed the realization of the above-mentioned object repeatedly. As a result, the inventors found that if the spherical silica is highly filled in the curable resin composition, as the blending amount of the resin component decreases, the water absorption as a cured product will decrease. On the other hand, B- HAST resistance or PCT resistance tend to deteriorate on the contrary. The inventors have made a new discovery through repeated research on this reason. It is known that if the highly filled spherical silica in the curable resin composition, through the interface of the inorganic filler and the resin, moisture easily penetrates into the resin from the surface of the cured product In the process, the ester bond of the resin in the hardened product will be hydrolyzed. Therefore, for this reason, the chemical structure of the epoxy resin which is the hardening component of the composition is further studied and reviewed. As a result, it was found that the use of an epoxy resin with a dicyclopentadiene skeleton as a bulky molecular structure as a hardening component unexpectedly inhibits the hydrolysis of the resin due to water molecules, thereby improving B-HAST resistance or PCT Patience finally completed the invention.

That is, the curable resin composition of the present invention is characterized by containing (A) a carboxyl group-containing resin, (B) an epoxy resin having a dicyclopentadiene skeleton, (C) a photopolymerization initiator and (D) Spherical silica, and the above-mentioned (D) spherical silica has this content as 50% by mass or more of the nonvolatile components of the composition.

In the curable resin composition of the present invention, the (B) epoxy resin having a dicyclopentadiene skeleton is 0.5 to 1 mol of the carboxyl group in the (A) carboxyl group-containing resin at an epoxy group ratio of 0.5 to 2.5 mol is preferred.

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

Furthermore, the cured product of the present invention is characterized in that the curable resin composition or the resin layer of the dry film is cured.

Furthermore, the printed wiring board of the present invention is characterized by having the above-mentioned cured product. [Effect of invention]

According to the curable resin composition of the present invention, not only the water absorption of the cured product can be reduced, but also the progress of hydrolysis of ester bonds and the like can be suppressed to prevent the deterioration of insulation or adhesion. As a result, the highly-filled inorganic filler such as spherical silica in the curable resin composition can also obtain B-HAST in addition to ensuring excellent reliability as a cured product such as high rigidity or excellent TCT resistance. A curable resin composition excellent in resistance and PCT resistance, a dry film using this, a cured product, and a printed wiring board. [Forms for carrying out the invention]

Hereinafter, the embodiment of the present invention will be described in detail. (Curable resin composition) The curable resin composition of the present invention contains (A) a carboxyl group-containing resin, (B) an epoxy resin having a dicyclopentadiene skeleton, (C) a photopolymerization initiator, and (D) spherical silica. Wherein (D) the content of spherical silica is 50% by mass or more of the non-volatile components of the composition.

In this way, it is considered that by making the composition containing (B) an epoxy resin having a dicyclopentadiene skeleton, the dicyclopentadiene skeleton having a (volume) bulky molecular structure can block the intersection of the hardened material. The free space in the joint structure inhibits the penetration of water molecules into the resin and inhibits the hydrolysis of the hardened resin due to the water molecules. As a result, even if the inorganic filler such as spherical silica is highly filled in the curable resin composition, excellent B- can be maintained while maintaining excellent reliability of the high rigidity or as a cured product with excellent TCT resistance. HAST resistance and PCT resistance.

[(A) Resin containing carboxyl group] For 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 preferred from the viewpoint of photocurability or development resistance. The ethylenically unsaturated double bond system is preferably derived from acrylic acid or methacrylic acid or derivatives thereof. When only a carboxyl group-containing resin having no ethylenic unsaturated double bond is used, the photoreactive monomer must be used in combination with a compound having a plurality of ethylenic unsaturated groups in the molecule described later because the composition becomes photocurable. Specific examples of the carboxyl group-containing resin include the following compounds (both oligomers and polymers may be used).

(1) By copolymerization of unsaturated carboxylic acids such as (meth)acrylic acid and unsaturated group-containing compounds such as styrene, α-methylstyrene, lower alkyl (meth)acrylates, and isobutylene Resins containing carboxyl groups.

(2) Diisocyanate such as aliphatic diisocyanate, branched aliphatic diisocyanate, alicyclic diisocyanate, aromatic diisocyanate, and carboxyl group containing dimethylolpropionic acid, dimethylolbutanoic acid, etc. Glycol compounds and polycarbonate-based polyols, polyether-based polyols, polyester-based polyols, polyolefin-based polyols, acrylic-based polyols, bisphenol A-based alkylene oxide adduct diols, phenolic Carboxyl-containing urethane resins are formed by the double addition reaction of diol compounds such as hydroxyl and alcoholic hydroxyl compounds.

(3) Diisocyanate, with bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bis-xylenol epoxy resin, double Photosensitive amines containing carboxyl groups are obtained by the double addition reaction of (meth)acrylates of bifunctional epoxy resins such as phenolic epoxy resins or their partial anhydride modifications, diol compounds containing carboxyl groups and diol compounds Carbamate resin.

(4) In the synthesis of the resin of (2) or (3) above, a compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecule such as hydroxyalkyl (meth)acrylate is added to make Carboxyl group-containing photosensitive urethane resin obtained by esterification of terminal (meth)acrylate.

(5) In the synthesis of the resin of (2) or (3) above, a mole reaction product such as isophorone diisocyanate and pentaerythritol triacrylate is added, and the molecule has one isocyanate group and one or more (a Group) acryloyl compound, the terminal (meth)acrylate esterification to form a carboxyl group-containing photosensitive urethane resin.

(6) A carboxyl group-containing photosensitive resin obtained by reacting a bifunctional or above multifunctional (solid) epoxy resin with (meth)acrylic acid and adding a 2-basic acid anhydride to the hydroxyl group present in the side chain.

(7) The hydroxy group of the 2-functional (solid) epoxy resin is further epoxidized with epichlorohydrin and the (meth)acrylic acid is reacted, and the resulting hydroxy group is added with 2-base acid anhydride to contain Carboxyl photosensitive resin.

(8) The bifunctional propylene oxide resin is reacted with dicarboxylic acid such as adipic acid, phthalic acid, hexahydrophthalic acid, etc., and phthalic anhydride and tetrahydrophthalic anhydride are added to the generated primary hydroxyl group , Hexahydrophthalic anhydride and other 2 base acid anhydride to obtain polyester resin containing carboxyl group.

(9) A compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule of an epoxy compound having a plurality of epoxy groups in one molecule, and p-hydroxyphenylethanol, (meth)acrylic acid The monocarboxylic acid containing unsaturated group is reacted with the alcoholic hydroxyl group of the resulting reaction product with maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic acid Such polyanhydrides react to obtain resins containing carboxyl groups.

(10) A compound having a plurality of phenolic hydroxyl groups in one molecule is reacted with alkylene oxide such as ethylene oxide and propylene oxide, and the resulting reaction product is reacted with an unsaturated group-containing monocarboxylic acid, and The resulting reaction product is reacted with a polybasic acid anhydride to obtain a carboxyl group-containing photosensitive resin.

(11) A compound having a plurality of phenolic hydroxyl groups in one molecule reacts with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate, and the resulting reaction product is reacted with a monocarboxylic acid containing an unsaturated group, and the resulting The reaction product reacts with polybasic acid anhydride to obtain a carboxyl group-containing photosensitive resin.

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

The acid value of the carboxyl group-containing resin is suitably in the range of 30 to 150 mgKOH/g, more preferably in the range of 50 to 120 mgKOH/g. If the acid value of the carboxyl group-containing resin is 30 mgKOH/g or more, alkali development is easy. On the other hand, if it is 150 mgKOH/g or less, the exposed part has sufficient resistance to the developing solution, so that a normal resist map can be drawn reliably. Type is better.

In addition, although the weight average molecular weight of the carboxyl group-containing resin varies depending on the resin skeleton, it is generally 2,000 to 150,000, and more preferably 5,000 to 100,000. If the weight average molecular weight is 2,000 or more, the development resistance of the film of the exposed portion is improved, and the resolution is excellent. On the other hand, if the weight average molecular weight is 150,000 or less, in addition to the good solubility of the unexposed portion and excellent resolution, storage stability is also improved. The weight average molecular weight can be determined by colloidal permeation chromatography.

These carboxyl group-containing resins are not limited to those listed above, and they may be used alone or in combination. Among them, as described above for the carboxyl group-containing resins (10) and (11), the carboxyl group-containing resin synthesized using the phenol compound as a starting material is preferred for use because of its excellent B-HAST resistance and PCT resistance.

[(B) Epoxy resin with dicyclopentadiene skeleton] (B) For epoxy resins having a dicyclopentadiene skeleton, for example, commercially available products such as EPICLONHP-7200 manufactured by DIC Corporation and ADEKARESINEP-4088L manufactured by ADEKA Corporation. (B) An epoxy resin having a dicyclopentadiene skeleton can be used alone or in combination of two or more.

This (B) epoxy resin with a dicyclopentadiene skeleton, with respect to 1 mol of carboxyl groups in (A) carboxyl group-containing resin, the ratio of epoxy groups is 0.5 to 2.5 mol, more preferably 0.8 to 2.0 mol It’s better to blend. When the blending amount of the component (B) is 0.5 mol or more, an excellent effect of improving the B-HAST resistance or PCT resistance of the cured product can be obtained. In addition, by setting the blending amount of the component (B) to 2.5 mol or less, good developability can be obtained.

In the curable resin composition, other epoxy resins may be further blended in addition to (B) the epoxy resin having a dicyclopentadiene skeleton, without impairing the effects unique to the present invention. Examples of such other epoxy resins include epoxidized vegetable oil; bisphenol A epoxy resin; hydroquinone epoxy resin; bisphenol epoxy resin; thioether epoxy resin; brominated epoxy resin ; Novolac epoxy resin; bisphenol novolac epoxy resin; bisphenol F epoxy resin; hydrogenated bisphenol A epoxy resin; epoxypropylamine epoxy resin; hydantoin ring Oxygen resin; alicyclic epoxy resin; trihydroxyphenylmethane type epoxy resin; bis-xylenol type or bisphenol type epoxy resin or mixture of these; bisphenol S type epoxy resin; bisphenol A phenolic Varnish epoxy resin; tetrahydroxyphenylethane epoxy resin; heterocyclic epoxy resin; diglycidyl phthalate resin; tetraglycidyl xylenol ethane resin; naphthyl Contains epoxy resin; epoxy propyl methacrylate copolymer epoxy resin; cyclohexyl maleimide and epoxy propyl methacrylate copolymer epoxy resin; epoxy modified polybutadiene Rubber derivatives; CTBN modified epoxy resin, etc., but not limited to these. In the curable resin composition of the present invention, when (B) an epoxy resin having a dicyclopentadiene skeleton is used in combination with other epoxy resins, relative to the total amount of epoxy resin, in terms of non-volatile content conversion, it is used as The component (B) of the above epoxy resin having a dicyclopentadiene skeleton preferably contains 10% by mass or more, and more preferably contains 20 to 80% by mass.

[(C) Photopolymerization initiator] (C) As for the photopolymerization initiator, any known ones can be used. (C) One type of photopolymerization initiator may be used alone, or two or more types may be used in combination.

(C) In terms of the photopolymerization initiator, specifically, for example, bis-(2,6-dichlorobenzyl)phenylphosphine oxide, bis-(2,6-dichlorobenzyl) )-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzene Methyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzyl) phenylphosphine oxide, bis-(2,6-dimethoxybenzyl) )-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzyl)-2,5-dimethylphenylphosphine oxide, bis-( 2,4,6-trimethylbenzyl)-phenylphosphine oxide and other bis-acetylphosphine oxides; 2,6-dimethoxybenzyl diphenylphosphine oxide, 2 ,6-Dichlorobenzyl diphenylphosphine oxide, 2,4,6-trimethylbenzyl phenylphosphinic acid methyl ester, 2-methylbenzyl diphenylphosphine Oxide, isopropyl trimethylacetoxyphenylphosphinate, 2,4,6-trimethylbenzyldiphenylphosphine oxide (Omnirad TPO manufactured by IGM), etc. Phosphine oxides; ethyl phenyl (2,4,6-trimethylbenzyl)phosphonate, 1-hydroxy-cyclohexyl phenyl 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-propane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one and other hydroxyacetophenones; benzoin, benzyl, benzoin Benzoin such as methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether, etc.; benzoin alkyl ethers; benzophenone, p-methyl benzophenone , Michler's ketone, methyl benzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone and other benzophenones; acetophenone, 2,2 -Dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morphol Phenylphenyl)-butanone-1, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl ] Acetophenones such as 1-butanone, N,N-dimethylaminoacetophenone; thioxanthone, 2-ethylthioxanthone, 2-isopropyl Thiothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2, Thioxanthones such as 4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butyl Anthraquinones such as anthraquinone, 1-chloroanthraquinone, 2-pentylanthraquinone, 2-aminoanthraquinone, etc.; acetophenone dimethyl ketal, Ketals such as benzyl dimethyl ketal; ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethylbenzoate, p-dimethylbenzoin Benzoic acid esters such as ethyl acid ester; 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyl oxime)], ethyl ketone, Oxime esters such as 1-[9-ethyl-6-(2-methylbenzyl)-9H-carbazol-3-yl]-,1-(O-acetoxyxime); bis( η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl) titanium, bis(cyclolocenyl)-bis(2 ,6-difluoro-3-(2-(1H-pyrrol-1-yl)ethyl)phenyl]titanium and other titanocenes; phenyl disulfide 2-nitrostilbene, butyroin, large Anisin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide, etc.

Among the above, it is preferable to use a mono-acylphosphine oxide-based photopolymerization initiator or a bis-acylphosphine oxide-based photopolymerization initiator, etc. because it has photobleaching properties. Here, so-called photobleaching is also referred to as photobleaching or photobleaching, and refers to a reaction in which a fluorescent substance in an excited state is chemically activated and becomes unstable compared to a substrate state. Specifically, when a compound acting as a photopolymerization initiator causes light to absorb light in a specific wavelength region to generate free radicals, the structure of the compound changes due to the generation of free radicals, making it impossible to absorb light in this wavelength region . Thereby, in this wavelength region, light easily passes through, and it is easy to photo-harden to the deep part. Especially suitable for 2,4,6-trimethylbenzyl-diphenylphosphine oxide (Omnirad TPO manufactured by IGM), bis(2,4,6-trimethylbenzyl)phenylphosphine oxide Substances (IRGACURE819 made by BASF JAPAN), ethyl phenyl (2,4,6-trimethylbenzyl)phosphonate (IRGACURE TPO-L made by BASF JAPAN), etc.

Excluding the oxime ester-based photopolymerization initiator, the blending amount of the photopolymerization initiator is based on the conversion of non-volatile components, and it is preferably 0.1 to 30 parts by mass relative to (A) 100 parts by mass of the carboxyl group-containing resin. . At 0.1 parts by mass or more, the photocurability of the resin composition is good, the coating film is difficult to peel off, and the coating film characteristics such as chemical resistance are also good. On the other hand, when it is 30 parts by mass or less, the effect of reducing outgassing can be obtained, and the light absorption on the surface of the solder resist coating film is good, making it difficult to reduce the deep hardenability. More preferably, it is 0.5 to 15 parts by mass. In addition, the blending amount of the oxime ester-based photopolymerization initiator is preferably 0.01 to 5 parts by mass relative to (A) 100 parts by mass of the carboxyl group-containing resin in terms of nonvolatile components. At 0.01 parts by mass or more, the photocurability of the resin composition is good, and the coating film characteristics such as heat resistance and chemical resistance are also good. On the other hand, when the amount is 5 parts by mass or less, the light absorption of the solder resist coating film will be improved, and it is difficult to reduce the deep curability. More preferably, it is 0.5 to 3 parts by mass.

[(D) spherical silica] (D) For spherical silica, any spherical silica that can be used as a filler for electronic materials can be used alone, or it can be used in combination of two or more. In addition, (D) the shape of the spherical silicon dioxide may be spherical as long as it is not limited to a regular spherical shape. The preferable (D) spherical silica is, for example, one having a positive sphericity of 0.8 or more as measured below, but it is not limited thereto.

The positive sphericity can be measured in the following manner. In other words, first, take a photograph of spherical silicon dioxide with a scanning electron microscope (SEM), and the area and perimeter of the particles observed on the photograph, with (positive sphericity) = {4π×(area) ÷(Perimeter) ² } Calculate the calculated value. Specifically, using an image processing device, an average of 100 particles can be measured.

In the present invention, in the aspect of (D) spherical silica, it is preferable to use spherical silica (D1) having an average particle diameter of 300 nm to 1000 nm, and more preferably to have an average particle diameter of 500 nm to 900 nm.

Here, in this specification, the average particle diameter of (D) spherical silica is not only the particle diameter of the primary particles but also the average particle diameter (D50) of the particle diameter of the secondary particles (agglomerates), and The value of D50 measured by the laser diffraction method. As for the measurement device of the laser diffraction method, Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd. can be cited. In addition, the maximum particle diameter (D100) and the particle diameter (D10) can be measured in the same manner as the above-mentioned apparatus.

In the present invention, (D) spherical silica, two types of spherical silica having different average particle diameters can be used. That is, spherical silica (D1) having an average particle diameter of 300 nm to 1000 nm and spherical silica (D2) having an average particle diameter of 1 nm or more and less than 300 nm can be used in combination. By using them together, the gap between the spherical silica (D1) can be filled with the spherical silica (D2), and the amount of gap can be reduced. Thereby, (D) spherical silica can be highly filled in the composition, and the resin content is small, which means that a curable resin composition with a high filler mass ratio in the total mass can be obtained.

Even if the general commercial product is in the same product, the particle diameter originally has a variation of 2 to 3 times, but at this ratio, the fine particles cannot effectively enter the gap, the spherical silica (D1) and the spherical two The average particle diameter of silicon oxide (D2) is preferably a difference of more than 5 times. The larger the average particle diameter ratio of spherical silica (D1) and spherical silica (D2), the better. The average particle diameter of the spherical silica (D1) is preferably 8 times or more, and 10 times or more the average particle diameter of the spherical silica (D2).

In addition, the maximum particle diameter (D100) of the spherical silica (D1) is preferably 5 μm or less. The maximum particle diameter varies depending on the application of the curable resin composition. For example, in the application of forming a cured film on a package substrate, it is preferably 5 μm or less. Furthermore, the particle diameter (D10) of the spherical silica (D1) is preferably more than 5 times the average particle diameter (D50) of the spherical silica (D2). If this ratio is more than 5 times, the filling efficiency of the spherical silica (D2) in the gap of the spherical silica (D1) will be improved, and the balance between the strength of the hardened product and the lamination of the dry film will be excellent.

In addition, the blending ratio when spherical silica (D1) and spherical silica (D2) are used together is recorded as spherical silica (D1) by volume ratio: spherical silica (D2) = 5 : 5-9:1 is better, 6:4-8:2 is even better. Within the above range, the strength of the cured product and the lamination of the dry film are both compatible and preferable.

The production method of spherical silica is not particularly limited, and a method known to those skilled in the art may be used. For example, by the VMC (Vaporized Metal Combustion) method, it can be manufactured by burning silicon powder. The so-called VMC method is to form a chemical flame by a burner in an oxygen-containing atmosphere. In this chemical flame, a part of the oxide particles constituting the target is put into the metal powder in an amount that can form a dust cloud to cause deflagration. Method for obtaining oxide particles.

In addition, for commercially available spherical silica, the spherical silica (D1) includes, for example, ADMAFINE SO-C2, SOE2 manufactured by ADMATECHS, SFP-20M and SFP- manufactured by DENKA Corporation. 30M, etc. For the spherical silica (D2), for example, ADMANANO® manufactured by ADMATECHS, UFP-30 manufactured by DENKA, SEAHOSTAR series manufactured by Japan Catalyst Co., Ltd., Sakai Chemical Sciqas series of industrial (share) system, SG-SO100 of KCM (share) system, etc.

(D) The presence or absence of surface treatment of spherical silica is not particularly limited, but the curable resin composition of the present invention is (D) spherical silica is highly filled and the resin content is relatively small, (D) ball In the form of silicon dioxide, it is preferable to implement a surface treatment for improving dispersibility. By using fillers with surface treatment, it is possible to suppress agglomeration. In addition, (D) spherical silica, when spherical silica (D1) and spherical silica (D2) are used together, only one of them may be surface-treated, or both may be used. Processor.

(D) The surface treatment method of spherical silica is not particularly limited. Although a well-known and usual method can be used, a surface treatment agent having a hardening reactive group, for example, a coupling having a hardening reactive group as an organic group The surface of the inorganic filler in the agent is preferred.

For the coupling agent, silane-based, titanate-based, aluminate-based, and zirconium-aluminate-based coupling agents can be used. Among them, silane-based coupling agents are preferred. Examples of the silane-based coupling agent include vinyl trimethoxysilane, vinyl triethoxysilane, N-(2-aminomethyl)-3-aminopropylmethyldimethoxysilane, N -(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-epoxypropoxy Trimethoxysilane, 3-glycidoxymethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloyloxypropane Trimethoxysilane, 3-mercaptopropyltrimethoxysilane, etc., these can be used alone or in combination. These silane-based coupling agents are preferably fixed in advance on the surface of the spherical silica by adsorption or reaction. Here, for 100 parts by mass of (D) spherical silica, the processing amount of the coupling agent is preferably 0.5 to 10 parts by mass. In addition, in the present invention, the reactive functional group derived from coupling applied to (D) spherical silica is not included in the compound having a photo-curable reactive group and a thermo-curable functional group.

Examples of the photocurable reactive group include ethylenic unsaturated groups such as vinyl group, styryl group, methacryloyl group, and acryloyl group. Among them, at least one of vinyl group and (meth)acryloyl group is more preferable.

As for the thermosetting reactive group, a hydroxyl group, carboxyl group, isocyanate group, amine group, imine group, epoxy group, oxetanyl group, mercapto group, methoxymethyl group, methoxyethyl group, ethyl group Oxymethyl, ethoxyethyl, oxazoline, etc. Among them, at least one of an amine group and an epoxy group is more preferable.

In addition, the surface-treated (D) spherical silica can be included in the curable resin composition of the present invention in a surface-treated state, and the surface-untreated (D) spherical silica is blended separately For the silica and the surface treatment agent, (D) spherical silica can be surface-treated in the composition, but it is preferable to blend (D) spherical silica that has been surface-treated in advance. By blending (D) spherical silica that has been surface-treated in advance, it is possible to suppress the decrease in crack resistance due to the surface treatment agent that is not consumed by the surface treatment that will remain during the respective blending. In the case of pre-surface treatment, it is preferable to prepare (D) spherical silica prepared by dispersing in a solvent or hardening component, and disperse the surface-treated (D) spherical silica prepared in a solvent Medium, and blend this pre-dispersion into the composition, or when the surface-untreated (D) spherical silica is pre-dispersed in a solvent, fully surface-treat it, and then blend this pre-dispersion The composition is better.

(D) Spherical silica, according to the use of the curable resin composition of the present invention, can be blended with the (A) component in powder or solid state, or mixed with a solvent or dispersant to form a slurry It is blended with the component (A).

(D) The content of spherical silica must be 50% by mass or more in the non-volatile components of the composition, preferably 50% by mass to 85% by mass, more preferably 70% by mass to 85% by mass, and more It is preferably 80% by mass to 85% by mass. By setting the content of (D) spherical silica to 50% by mass or more in the non-volatile content of the composition, the hardened material can be made to have high strength and high rigidity, and the coefficient of linear expansion (CTE) can be reduced. good.

[Photopolymerizable monomer] The curable resin composition of the present invention may contain a photopolymerizable monomer. The photopolymerizable single system has 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 ( Hydroxyalkyl (meth)acrylates such as meth)acrylate and 2-hydroxypropyl (meth)acrylate; alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol Mono- or di(meth)acrylates; polyols such as hexanediol, trimethylolpropane, pentaerythritol, di-trimethylolpropane, dipentaerythritol, hydroxyethyl isocyanurate, etc. or Polyvalent (meth)acrylates of these ethylene oxide or propylene oxide adducts; phenoxyethyl (meth)acrylate, polyethoxydi (methyl) of bisphenol A (Meth)acrylates of phenols such as acrylates, ethylene oxide or propylene oxide adducts; glycerol diglycidyl ether, trimethylolpropane triglycidyl ether, tris (Meth)acrylates of glycidyl ethers such as epoxypropyl isocyanurate; and melamine (meth)acrylates.

The photopolymerizable monomer may be used alone or in combination of two or more. The content of the photopolymerizable monomer is preferably a ratio of 0.5 to 20 parts by mass relative to (A) 100 parts by mass of the carboxyl group-containing resin in terms of nonvolatile components. When the blending amount is 0.5 parts by mass or more, the photocurability is good, and in alkaline development after active energy ray irradiation, pattern formation is easy. On the other hand, when it is 20 parts by mass or less, halo is difficult to generate, and good resolution can be obtained.

[Thermosetting catalyst] In the curable resin composition of the present invention, a thermosetting catalyst can be blended. For the thermosetting catalyst, for example, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyano Imidazole derivatives such as ethyl-2-phenylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4-( (Dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl-N,N-dimethylbenzylamine Amine compounds such as amine compounds, adipic acid adipamide hydrazine, sebacic acid adipamide hydrazine, etc.; phosphorus compounds such as triphenylphosphine. In addition, guanamine, methylguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloxyethyl-S-triazine, 2-vinyl-2 can also be used ,4-diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine･cyanuric acid adduct, 2,4-diamino-6-methyl S-triazine derivatives such as acryloxyethyl-S-triazine and cyanuric acid adducts are preferably used in combination with a compound that functions as such an adhesion-imparting agent and a thermosetting catalyst .

The thermosetting catalyst can be used alone or in combination of two or more. The blending amount of the thermosetting catalyst is based on the conversion of nonvolatile components, and is preferably 0.5 to 10 parts by mass, and more preferably 1 to 8 parts by mass relative to (A) 100 parts by mass of the carboxyl group-containing resin. When it is 0.5 parts by mass or more, heat resistance is excellent. When it is less than 10 parts by mass, the storage stability will be improved.

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

Specifically, a number with a color index (C.I.; issued by The Society of Dyers and Colourists) can be cited.

For the red colorant, there are monoazo system, diazo system, azo lake system, benzimidazolone system, perylene system, pyrrolopyrrole dione system, condensed azo system, anthraquinone system, quinacridone system, etc. . For the cyan colorant, there are phthalocyanine-based and anthraquinone-based compounds, and pigment-based compounds classified into pigments can be used. In addition to these, metal-substituted or unsubstituted phthalocyanine compounds can also be used. As for the green colorant, there are phthalocyanine-based, anthraquinone-based, and perylene-based. In addition to these, metal-substituted or unsubstituted phthalocyanine compounds can also be used. As for the yellow colorant, there are monoazo system, diazo system, condensed azo system, benzimidazolone system, isoindolinone system, anthraquinone system, etc. As for the white colorant, a rutile-type or tetragonal-type acidified titanium can be mentioned. For black colorants, there are carbon black, black lead, acidified iron, titanium black, anthraquinone, cobalt oxide, copper oxide, manganese, antimony oxide, nickel oxide, perylene, and aniline. , Molybdenum sulfide, bismuth sulfide, etc. In addition, for the purpose of adjusting the color tone, colorants such as purple, orange, and brown can also be added.

The content of the coloring agent is preferably 0.18 to 0.50% by mass in terms of nonvolatile content in terms of the total curable resin composition from the viewpoint of improving the concealability of the cured product. Under the conversion of non-volatile components, when it contains 0.18% by mass or more, the circuit shielding property is excellent, and when it contains 0.50% by mass or less, the resolution is better. More preferably, it is 0.20 mass%-0.40 mass %.

[Organic solvents] The curable resin composition of the present invention may contain an organic solvent for the purpose of preparing the composition or adjusting the viscosity when applied to a substrate or a film. For organic solvents, ketones such as methyl ethyl ketone and cyclohexanone can be used; aromatic hydrocarbons such as toluene, xylene, tetramethyl benzene, etc.; Selous, Methyl Selul, and Butyl Selul Su, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, Glycol ethers such as tripropylene glycol monomethyl ether, etc.; ethyl acetate, butyl acetate, butyl lactate, celozul acetate, butyl celozul acetate, carbitol acetate , Butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, propylene carbonate and other esters; octane, decane and other aliphatic hydrocarbons; petroleum ether , Petroleum petroleum naphtha, solvent petroleum naphtha and other petroleum-based solvents and other well-known and commonly used organic solvents. These organic solvents can be used alone or in combination of two or more.

[Other added ingredients] The hardening resin composition of the present invention may further be blended with a photoinitiator, a cyanate compound, an elastomer, a mercapto compound, an urethane catalyst, a thixotropic agent, and an adhesive if necessary. Accelerators, block copolymers, chain transfer agents, polymerization inhibitors, copper anti-corrosion agents, antioxidants, rust inhibitors, fine powdered silicon oxide, organic bentonite, montmorillonite and other tackifiers, polysiloxane, Fluorine-based, polymer-based antifoaming agents and/or leveling agents, imidazole-based, thiazole-based, triazole-based silane coupling agents, phosphonates, phosphoric acid ester derivatives, phosphorous azo compounds, etc. Components such as compounds such as flame retardants. These systems can be used as known in the field of electronic materials.

The curable resin composition of the present invention may be used after being dried into a thin film, or may be used as a liquid. In addition, when used as a liquid, it may be one-liquid or more than two-liquid.

The curable resin composition of the present invention can be used to form a patterned layer as a permanent coating of a printed wiring board such as a solder resist, a coating layer, an interlayer insulating layer, etc., and is particularly useful for forming a solder resist. In addition, the curable resin composition of the present invention can form a cured product having excellent film strength even in a thin film, and thus can be applied to printed wiring boards requiring thinning, and is also suitable for packaging substrates (printed wiring used in semiconductor packages, for example) Board) the formation of patterned layers. Furthermore, the cured product obtained from the curable resin composition of the present invention can be applied to the formation of a patterned layer in a package substrate with a thin overall thickness and insufficient rigidity, from the point of high elasticity and low CTE.

[Dry film] The curable resin composition of the present invention may be in the form of a dry film provided with a support (carrier) film and a resin layer formed of the curable resin composition formed on the support film. When the film is dried, the curable resin composition of the present invention is diluted with the above-mentioned organic solvent, adjusted to a suitable viscosity, and used with a corner wheel coater, blade coater, lip coater, bar coater , Extrusion coater, reverse coater, transfer roll coater, gravure coater, spray coater is equal to the coating on the carrier film to a uniform thickness, usually can be dried at a temperature of 50 to 130 ℃ for 1 to 30 minutes And get the film. Although the thickness of the coating film is not particularly limited, in general, the thickness after drying is appropriately selected in the range of 1 to 150 μm, preferably 10 to 60 μm.

For the support film, plastic film can be used, and polyester film such as polyethylene terephthalate (PET), polyimide film, polyimide film, polypropylene film, polystyrene can be used Plastic films such as film are preferred. Although the thickness of the support film is not particularly limited, in general, it may be appropriately selected within the range of 10 to 150 μm.

After forming the resin layer of the curable resin composition of the present invention on the support film, the surface of the resin layer is used for the purpose of preventing the adhesion of dust, etc., preferably a protective (coating) film that can be peeled off on the surface area of the resin layer. For the peelable protective film, for example, polyethylene film, polytetrafluoroethylene film, polypropylene film, surface-treated paper, etc. can be used. When peeling the protective film, if the adhesion between the resin layer and the protective film is The adhesive force between the resin layer and the supporting film may be smaller.

In addition, in the present invention, the curable resin composition of the present invention may be coated on the protective film and dried to form a resin layer to support the film on the surface layer. That is, when manufacturing the dry film of the present invention, either of the supporting film and the protective film may be used for coating the film of the curable resin composition of the present invention.

[Hardened] The cured product of the present invention is obtained by curing the above-mentioned curable resin composition of the present invention or the resin layer of the above-mentioned dry film of the present invention, and has high rigidity and thermal dimensional stability.

[Printed wiring board] The printed wiring board of the present invention is a cured product obtained from the curable resin composition of the present invention or the resin layer of a dry film. In the aspect of the method for manufacturing a printed wiring board of the present invention, for example, the above organic solvent is used to adjust the viscosity to a suitable coating method, and the substrate is coated by dip coating, flow coating, roll coating, or bar coating. After applying the curable resin composition of the present invention by a cloth method, screen printing method, curtain coating method, etc., the organic solvent contained in the composition is volatilized and dried at a temperature of 60 to 100°C (temporary drying), A non-adhesive resin layer is formed. In addition, when the film is dried, the resin layer is formed on the substrate by peeling off the supporting film after the resin layer is brought into contact with the substrate by a laminator or the like, and then the substrate is peeled off.

For the above-mentioned substrates, in addition to printed wiring boards or flexible printed wiring boards that can be formed into circuits by copper or the like in advance, available paper phenol, paper epoxy resin, glass cloth epoxy resin, glass polyacrylic acid are used For high-frequency circuits such as imine, glass cloth/non-fiber epoxy resin, glass cloth/paper epoxy resin, synthetic fiber epoxy resin, fluororesin, polyethylene, polyphenylene ether, polyphenylene ether, cyanate, etc. For materials such as copper-clad laminates, in addition to copper-clad laminates of all grades (FR-4, etc.), other examples include metal substrates, polyimide films, polyethylene terephthalate films, and polyethylene naphthalene. Formic acid (PEN) film, glass substrate, ceramic substrate, wafer board, etc.

The volatile drying performed after applying the curable resin composition of the present invention can use a hot air circulation drying furnace, IR furnace, heating plate, convection oven, etc. (using a heat source with an air heating method by steam, The method of making hot air exchange contact in the dryer and the method of blowing from the nozzle to the support).

After forming a resin layer on the substrate, through a mask with a predetermined pattern, it is selectively exposed to active energy rays, and the unexposed part is passed through a dilute alkaline aqueous solution (for example, 0.3 to 3 mass% sodium carbonate (Aqueous solution) development, forming a pattern of hardened material. Furthermore, the hardened material is irradiated with active energy rays and then heat-cured (for example, 100 to 220° C.), or irradiated with active energy rays after heat-hardened, or only hardened by heat curing as the final treatment (hardening), thereby forming A cured film with excellent characteristics such as adhesion and hardness.

The exposure machine used for the above-mentioned active energy ray irradiation may be a device equipped with a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halogen lamp, a mercury short-circuit arc lamp, etc., and irradiating ultraviolet rays in the range of 350 to 450 nm. A direct drawing device (for example, a laser direct imaging device that draws an image with a direct laser based on CAD data from a computer) can be used. For the lamp light source or laser light source of the direct tracer, it should be within the range of the maximum wavelength of 350-450nm. The exposure amount for image formation varies depending on the film thickness and the like, but generally it can be 10 to 1000 mJ/cm ² , preferably 20 to 800 mJ/cm ² .

The above-mentioned developing method can be implemented by dipping method, shower method, spraying method, brushing method, etc., and the developing solution can use potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, silicon Alkaline aqueous solution of sodium, ammonia, amine, etc.

The curable resin composition of the present invention can be used not only for the application of the pattern of the cured film formed by the above-mentioned developing solution, but also for applications where the pattern is not formed, for example, a mold application (sealing application).

[Example]

Hereinafter, the present invention will be described in further detail with examples and comparative examples, but the present invention is not limited to these examples and comparative examples. In addition, in the following, "parts" and "%" are all quality standards unless otherwise specified.

(Synthesis Example 1) (Synthesis of carboxyl group-containing photosensitive resin A-1) Novolac-type cresol resin (commodity) Name "SHONOL CRG951", Showa Denko Co., Ltd., OH equivalent: 119.4) 119.4 parts by mass, potassium hydroxide 1.19 parts by mass, and toluene 119.4 parts by mass. Continue stirring to replace nitrogen in the system and heat up. Next, 63.8 parts by mass of propylene oxide was slowly dropped and reacted at 125 to 132°C and 0 to 4.8 kg/cm ² for 16 hours. After that, it was cooled to room temperature, 1.56 parts by mass of 89% phosphoric acid was added to this reaction solution, and potassium hydroxide was neutralized to obtain 62.1% of non-volatile matter and a hydroxyl value of 182.2 mgKOH/g (307.9 g/eq.). Propylene oxide reaction solution of novolac type cresol resin. In this system, propylene oxide is added to the equivalent of 1 equivalent per phenolic hydroxyl group and the average is 1.08 mole.

293.0 parts by mass of propylene oxide reaction solution of the obtained novolac-type cresol resin, 43.2 parts by mass of acrylic acid, 11.53 parts by mass of methanesulfonic acid, 0.18 parts by mass of methylhydroquinone, and 252.9 parts by mass of toluene were introduced into a blender, thermometer, and air The reactor was blown into the tube, air was blown in at a rate of 10 ml/min, and the mixture was reacted at 110° C. for 12 hours with stirring. The water system produced by the reaction and toluene are azeotropic mixtures, and 12.6 parts by mass of water is distilled off. After cooling to room temperature, the resulting reaction solution was neutralized with 35.35 parts by mass of 15% aqueous sodium hydroxide solution, followed by water washing. Thereafter, toluene was substituted with 118.1 parts by mass of diethylene glycol monoethyl ether acetate in the evaporator and distilled off to obtain a novolac acrylate resin solution. Next, 332.5 parts by mass of the obtained novolac acrylate resin solution and 1.22 parts by mass of triphenylphosphine were introduced into a reactor equipped with a stirrer, thermometer, and air blowing tube, and air was blown in at a rate of 10 ml/min. While stirring, 60.8 parts by mass of tetrahydrophthalic anhydride was slowly added, and allowed to react at 95 to 101°C for 6 hours, and then taken out after cooling. In this way, a solution of a photosensitive carboxyl group-containing resin having a nonvolatile content of 70.6% by mass and a solid content of acid value of 87.7 mgKOH/g was obtained.

(Modulation example 1) (Surface-treated spherical silica B-1 modulation) 70 parts by mass of spherical silica (SFP-30M manufactured by Denka Corporation, average particle diameter: 600 nm), 28 parts by mass of PMA (propylene glycol monomethyl ether acetate) as a solvent and silane having a methacryloyl group Coupling agent (KBM-503 (3-methacryloyloxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.) was uniformly dispersed in 2 parts by mass to obtain a silica oxide solvent dispersion product having a nonvolatile content of 70% by mass.

(Modulation example 2) (Surface-treated spherical silica B-2 modulation) 70 parts by mass of spherical silica (SG-SO100 made by Kyoritsu-KCM (share), average particle size d50=100nm), 28 parts by mass of PMA (propylene glycol monomethyl ether acetate) as a solvent and Methacryloyl silane coupling agent (KBM-503 (3-methacryloyloxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.) is uniformly dispersed in 2 parts by mass, resulting in oxidation of 70% by mass of nonvolatile components Silicone solvent dispersion.

<Preparation of curable resin composition> The components were blended according to the blending shown in Table 1 below, and after premixing with a blender, they were dispersed, kneaded with a 3-roll mill mixer, and each of the curable resin compositions was prepared. The blending amount in the table represents parts by mass. Using the obtained curable resin compositions of Examples and Comparative Examples, the following evaluations were performed.

<Evaluation of CTE> The curable resin composition of each example and comparative example was applied all over the copper foil substrate. This was dried and allowed to cool to room temperature, thereby forming a resin layer composed of a curable resin composition. For this, exposure was performed through a short grid-shaped negative mask of 50 mm×3 mm at an optimal exposure amount. After that, development was carried out by spraying a 1% by mass sodium carbonate aqueous solution at 30° C. to obtain a pattern of the cured film. Further, heating and curing were performed under predetermined conditions to obtain an evaluation substrate.

The cured film of the evaluation substrate obtained above was peeled from the copper foil, and evaluation was performed. The measurement was performed using a TMA measuring device (Shimazu Corporation TMA/SS6000), and CTEα1 (0-50°C) was determined. The criterion is as follows. ○…less than 30ppm ×…30ppm or more

<Evaluation of B-HAST resistance> On the BT substrate on which the comb-shaped electrode (line/pitch=20 μm/15 μm) was formed, a cured coating of the curable resin composition of each example and comparative example was formed to produce an evaluation substrate. This evaluation substrate was placed in a high-temperature and high-humidity tank under an atmosphere of 130° C. and a humidity of 85%, and a voltage of 5 V was applied to perform a HAST test in the tank. The elapsed time when the insulation resistance value in the tank was less than 10 ⁶ Ω was evaluated according to the following judgment criteria. ◎: Over 400 hours 〇: 200 to 400 hours ×: Less than 200 hours

<Evaluation of TCT resistance> The curable resin composition of each example and the comparative example was applied all over the package substrate. This was dried and allowed to cool to room temperature, thereby forming a resin layer composed of a curable resin composition. For this, direct imaging exposure was performed on the copper pad with an opening size of SRO (Solder Resist Opening) 80 μm at an optimal exposure amount. After that, development was carried out by spraying a 1% by mass sodium carbonate aqueous solution at 30° C. to obtain a pattern of the cured film. Then heat and harden under predetermined conditions. After that, Au plating treatment and solder bump formation were performed, and the Si wafer was mounted to obtain an evaluation substrate.

The evaluation substrate obtained above was placed in a cold-heat cycler with a temperature cycle 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 criterion is as follows. ◎: No abnormality at 1000 cycles ○: No abnormality at 800 cycles, cracks at 1000 cycles △: No abnormality at 600 cycles, cracks at 800 cycles ×: Cracks occurred at 600 cycles

<Evaluation of PCT resistance> The curable resin composition of each example and the comparative example was applied all over the package substrate. This was dried and allowed to cool to room temperature, thereby forming a resin layer composed of a curable resin composition. In this regard, direct imaging exposure was performed on the copper pad with the opening size of SRO 80 μm at the optimal exposure amount. After that, development was carried out by spraying a 1% by mass sodium carbonate aqueous solution at 30° C. to obtain a pattern of the cured film. Further, heating and curing were performed under predetermined conditions to obtain an evaluation substrate.

The obtained evaluation substrate was subjected to a PCT (Pressure Cooker Test) for 168 hours under conditions of 121° C., saturation, and 0.2 MPa using a PCT device (HAST SYSTEM TPC-412MD manufactured by ESPEC). Then, the state of the coating film after PCT was evaluated. The criterion is as follows. ○: No swelling, flaking, discoloration, dissolution ×: More common swelling, peeling, discoloration, dissolution

The evaluation results are shown in the following table.

*1) The photosensitive resin A-1 containing carboxyl group obtained in Synthesis Example 1 ＊2) HP-7200 (dicyclopentadiene type epoxy resin, DIC (stock), epoxy equivalent 260g/eq) ＊3) jER834 (bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 250g/eq) ＊4) N-730 (phenol novolac epoxy resin, DIC (stock), epoxy equivalent 175g/eq) ＊5) EOCN1020 (cresol novolac epoxy resin, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 200g/eq) ＊6) TPO (2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, Omnirad TPO, manufactured by IGM) *7) Surface-treated spherical silica B-1 obtained in Preparation Example 1 (methacrylic silane treatment, average particle diameter 600 nm, non-volatile content 70% by mass) ＊8) Surface-treated spherical silica B-2 obtained in Preparation Example 2 (methacrylic silane treatment, average particle diameter 100 nm, non-volatile content 70% by mass) ＊9) DPHA (dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.)

From the evaluation results shown in the above table, it is clear that in each example, in addition to ensuring excellent reliability of rigidity, TCT resistance, etc. as a cured product, it is confirmed that B-HAST resistance or PCT resistance can also be improved The curable resin composition.

Claims (4)

A curable resin composition characterized by (A) Resins containing carboxyl groups, (B) Epoxy resin with dicyclopentadiene skeleton, (C) Photopolymerization initiator, and (D) spherical silica, The content of the aforementioned (D) spherical silica is 50% by mass or more of the non-volatile components of the composition. A dry film characterized by having a resin layer obtained from the curable resin composition of claim 1. A hardened product characterized by hardening the curable resin composition of claim 1 or the resin layer of the dry film of claim 2. A printed wiring board characterized by the hardened product of claim 3.