TW201942247A - Curable resin composition, dry film formed of the composition, cured product and printed wiring board having the cured product capable of avoiding problems such as solder resist peeling and undercut - Google Patents

Abstract

Provided are a curable resin composition, which is excellent in analytical properties and is excellent in high-temperature and high-humidity resistance (PCT resistance) or thermal cycling resistance (TCT resistance) of a cured product even if it is filled with spherical silicon oxide; a dry film formed of the composition; a cured product and a printed wiring board having the cured product. The solution is to provide a curable resin composition comprising: (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) an epoxy resin, and (D) an inorganic filler, and is characterized in that: an epoxy resin (C) is a type of biphenyl skeleton epoxy resin or other type of epoxy resin which is solid or semi-solid at normal temperature; and an inorganic filler (D) containing spherical silicon oxide and barium sulfate which has a ratio of spherical silicon oxide to barium sulphate that is 1:(0.5 to 5) by volume.

Description

Curable resin composition, dry film formed from the composition, cured product, and printed wiring board having the cured product

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

Conventionally, as a material for forming a permanent film such as a solder resist in a printed wiring board by exposure and development, a curable resin composition that can be developed by an alkaline aqueous solution is used.
On the other hand, with the increase in the density of printed wiring boards for electronic devices that are thinner and shorter, in order to respond to this, the practicalization and mass production of miniaturization or multi-pinning of semiconductor packages have been developed. Recently, they have been gradually adopted. Instead of semiconductor packages called QFP (Quad Flat Package) or SOP (Small Outline Package), semiconductor packages such as BGA (Ball Ball Array) or CSP (Chip Scale Package) packages are used.
In such a package substrate, since wiring patterns are formed at a higher density and closer to each other, a permanent film such as a solder resist used in the package substrate is required to have excellent resolution and performance. Reliability of circuit protection film (pressure cooker test (PCT), cold and hot cycle test (TCT)).
As a method for suppressing the occurrence of cracks or peeling of such a solder resist for a package substrate, extensive research has been made, for example, by filling an inorganic filler into a curable resin composition to make the solder resist and the wiring substrate which is the base of the solder resist The linear thermal expansion coefficients are as uniform as possible. Among these inorganic fillers, spherical silica in particular has excellent filling properties and a low coefficient of thermal expansion (CTE), and is therefore widely used for improving the characteristics of solder resists (see Patent Document 1).
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2014-81611

[Problems to be Solved by the Invention]

However, if an inorganic filler such as spherical silica is filled in the curable resin composition, the spherical silica will hinder the transmission of light during pattern exposure by light irradiation of the coating film. Reduces the hardenability of the hardenable resin composition in the deep part of the coating film. In the subsequent development, the bottom of the coating film of the pattern of the solder resist is excessively dissolved (that is, undercut). This may cause problems such as poor formation of thin line patterns, deterioration of resolution, and the like.
In addition, if an undercut occurs, the ground area with the substrate is reduced, and therefore problems such as peeling of the solder resist are likely to occur in the high temperature and high humidity resistance test (PCT) or cold and heat cycle resistance test (TCT).

As a means for suppressing this, for example, there is a method of shortening the development time or lowering the temperature of the developing solution. However, in order to improve the adhesion with the solder resist, in general, surface treatment is performed on the copper circuit of the substrate. Due to the influence of the surface treatment layer described above, there are some cases where the undercut is suppressed by adjusting the development conditions. Other problems with the phenomenon of spherical silica remaining on the copper circuit at the bottom of the opening (that is, development residue).

Therefore, the object of the present invention is to provide an excellent resolving property even when the spherical silica is filled, and the high temperature and high humidity resistance (PCT resistance) or cold and heat cycle resistance (TCT resistance) of the cured product is also excellent. A resin composition, a dry film formed from the composition, such a cured product, and a printed wiring board having the cured product.

[Means for solving problems]

The present inventors focused on using barium sulfate in combination, and the barium sulfate system has a deeper hardening effect than spherical silica, and has conducted intensive studies in order to achieve the above-mentioned object. As a result, it has been found that when spherical silicon dioxide and barium sulfate are used in combination in a well-balanced manner, low CTE can be maintained while undercutting can be prevented.
Furthermore, in addition to the above-mentioned configuration, in order to solve the problem of the above-mentioned development residue, as a configuration that does not generate an undercut even if the development time is increased, an intensive study is focused on the epoxy component. As a result, it has been found that when an epoxy resin having a biphenyl skeleton is used in combination with an epoxy resin that is solid or semi-solid at ordinary temperatures other than the epoxy resin, it can be more reliably prevented from being affected by the development conditions. Undercut.

The present inventors have completed the present invention based on the above findings.
That is, the curable resin composition of the present invention contains (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) an epoxy resin, and (D) an inorganic filler, and is characterized in that the ( C) an epoxy resin containing an epoxy resin having a biphenyl skeleton and other solid or semi-solid epoxy resins at room temperature; as the (D) inorganic filler, containing spherical silica and barium sulfate; and The volume ratio of spherical silica and barium sulfate is 1: (0.5 ~ 5).

In the curable resin composition of the present invention, the (B) photopolymerization initiator preferably contains an acylphosphine oxide-based polymerization initiator.

Furthermore, the dry film of the present invention is obtained by coating the film with a curable resin composition and drying it.

Furthermore, the cured product of the present invention is characterized in that the dry film is obtained by coating the film with the alkali-developing curable resin composition or the alkali-developing curable resin composition, and drying the film, This dry film is then subjected to at least one of photocuring and thermal curing to obtain a cured product.

Furthermore, the printed wiring board of this invention is characterized by having the said hardened | cured material.

[Effect of the invention]

According to the present invention, it is possible to provide a hardening resin composition that is excellent in resolvability even if it is filled with spherical silica, and the cured product has high temperature and high humidity resistance (PCT resistance) or cold and heat cycle resistance (TCT resistance). , And a dry film made of the composition, such cured products, and a printed wiring board having the cured products.

[Best Mode for Implementing Invention]

The curable resin composition according to the present invention comprises (A) a resin containing a carboxyl group, (B) a photopolymerization initiator, (C) an epoxy resin, and (D) an inorganic filler, and is characterized in that the ( C) an epoxy resin containing an epoxy resin having a biphenyl skeleton and other solid or semi-solid epoxy resins at room temperature; as the (D) inorganic filler, containing spherical silica and barium sulfate; and The mixing ratio of the spherical silica and the barium sulfate is 1: (0.5 to 5) in volume ratio.
Hereinafter, each component of the curable resin composition of the present invention will be described in detail.

[(A) Carboxyl-containing resin]
As the (A) carboxyl group-containing resin system, various conventionally known carboxyl group-containing resins having a carboxyl group in a molecule can be used. In particular, a carboxyl group-containing photosensitive resin having an ethylenically unsaturated double bond in the molecule is preferable in terms of photocurability or development resistance. The ethylenically unsaturated double bond is preferably acrylic acid or methacrylic acid or a derivative derived therefrom. When only a carboxyl group-containing resin having no ethylenically unsaturated double bond is used, in order to make the composition photocurable, it is necessary to use a compound having a plurality of ethylenically unsaturated groups in a molecule described later (that is, light Reactive monomer).
Specific examples of the carboxyl group-containing resin include the following compounds (any one of an oligomer and a polymer may be used).

(1) Unsaturated carboxylic acids such as (meth) acrylic acid, and unsaturated group-containing compounds such as styrene, α-methylstyrene, low-order (meth) acrylic acid alkyl esters, and isobutylene A carboxyl group-containing resin obtained by polymerization.

(2) A carboxyl group containing a diisocyanate such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate, an aromatic diisocyanate, and dimethylolpropionic acid, dimethylolbutanoic acid, etc. Diol compounds and polycarbonate-based polyols, polyether-based polyols, polyester-based polyols, polyolefin-based polyols, acrylic-based polyols, bisphenol A-based alkylene oxide adduct diols, and phenols Carboxyl group-containing urethane resin obtained by polyaddition reaction of a diol compound such as a polar hydroxyl group and an alcoholic hydroxyl compound.

(3) With diisocyanate, bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bixylenol epoxy resin (Meth) acrylates of bifunctional epoxy resins, such as biphenyl epoxy resins, or carboxyl group-containing compounds obtained by polyaddition reaction of the partially acid anhydride-modified product, diol compounds containing carboxyl groups, and diol compounds Photosensitive urethane resin.

(4) In the synthesis of the resin of (2) or (3) above, a compound having one hydroxyl group and one or more (meth) acrylfluorenyl groups in a molecule is added, such as hydroxyalkyl (meth) acrylate. And the obtained carboxyl group-containing photosensitive urethane resin having a (meth) acrylic terminal.

(5) In the synthesis of the resin of (2) or (3) above, a mole reactant such as isophorone diisocyanate and pentaerythritol triacrylate is added, which has one isocyanate group and one or more ( A meth) acrylfluorene-based compound, and a carboxyl group-containing photosensitive urethane resin having a (meth) acrylic terminal at the end.

(6) 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 present in a branched chain.

(7) The hydroxyl group of the bifunctional (solid) epoxy resin is further epoxidized with epichlorohydrin to obtain a polyfunctional epoxy resin, and (meth) acrylic acid is reacted with the polyfunctional epoxy resin to produce The hydroxy group is added to a dibasic acid anhydride to obtain a carboxyl group-containing photosensitive resin.

(8) reacting dicarboxylic acids such as adipic acid, phthalic acid, hexahydrophthalic acid and the like with a bifunctional oxetane resin to add the generated primary hydroxyl groups to phthalic anhydride, Tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and other dibasic acid anhydrides, and carboxyl-containing polyester resins obtained.

(9) An epoxy compound having a plurality of epoxy groups in one molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule with p-hydroxyphenylethanol, and the like, and (methyl) For unsaturated monocarboxylic acids such as acrylic acid, maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic acid, etc. are used for the alcoholic hydroxyl group of the obtained reaction product. The polyacid is reacted to obtain a carboxyl-containing resin.

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

(11) A reaction product is obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate, propylene carbonate, etc., and using an unsaturated monocarboxylic acid and This reaction product reacts, and the polyacid is reacted with the obtained reaction product to obtain a carboxyl group-containing photosensitive resin.

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

The acid value of the carboxyl group-containing resin is preferably in the range of 30 to 150 mgKOH / g, and more preferably in the range of 50 to 120 mgKOH / g. When the acid value of the carboxyl group-containing resin is 30 mgKOH / g or more, alkali development becomes easy. On the other hand, when the acid value of the carboxyl group is 150 mgKOH / g or less, sufficient resistance to the developing solution in the exposed portion can be obtained, and it can be sure. It is better to draw a normal resist pattern.

The weight average molecular weight of the carboxyl group-containing resin varies depending on the resin skeleton, and is usually 2,000 to 150,000, and more preferably in the range of 5,000 to 100,000. When the weight average molecular weight is 2,000 or more, the development resistance of the film of 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 and the resolution is excellent, and at the same time, the storage stability is also improved. The weight average molecular weight can be measured by gel permeation chromatography.

These carboxyl group-containing resins are not limited to those listed above, and may be used singly or in combination. Among them, phenol compounds such as the carboxyl group-containing resins (10) and (11) are used as starting materials, and the synthesized carboxyl group-containing resin is suitably used because it has excellent B-HAST resistance and PCT resistance.

[(B) Photopolymerization initiator]
As the (B) photopolymerization initiator system, a known species can be arbitrarily used. (B) A photopolymerization initiator system may be used individually by 1 type, and may use 2 or more types together.

Specific examples of the (B) photopolymerization initiator include bis- (2,6-dichlorobenzylidene) phenylphosphine oxide, and bis- (2,6-dichlorobenzylidene)- 2,5-dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzylidene) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzylidene) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzyl) phenylphosphine oxide, bis- (2,6-dimethoxybenzyl) -2,4, 4-trimethylpentylphosphine oxide, bis- (2,6-dimethoxybenzylidene) -2,5-dimethylphenylphosphine oxide, bis- (2,4,6-trimethyl Dibenzylphosphine oxide) -bisphosphonylphosphine oxides such as phenylphosphine oxide; 2,6-dimethoxybenzyldiphenylphosphine oxide, 2,6-dichlorobenzyldioxane Phenylphosphine oxide, 2,4,6-trimethylbenzylidenephenylphosphonic acid methyl ester, 2-methylbenzylidenediphenylphosphine oxide, trimethylacetamidophenylphosphonic acid Monoisopropylphosphine oxides such as isopropyl esters, 2,4,6-trimethylbenzylidenediphenylphosphine oxide; phenyl (2,4,6-trimethylbenzylidene) Ethyl phosphinate, 1-hydroxy-cyclohexylphenyl ketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one 2-hydroxy-1 -Fluorene 4- [4- (2-hydroxy-2-methyl-propanyl) -benzyl] phenylfluorene-2-methyl-propane-1-one, 2-hydroxy-2-methyl-1 -Hydroxyacetophenones such as phenylpropane-1-one; benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl Benzoin, benzoin n-butyl ether, etc .; benzoin alkyl ethers; benzophenone, p-methylbenzophenone, Michelin, methylbenzophenone Ketones, 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 acetone, 2-benzyl-2-dimethylamino-1- (4-morpholinylphenyl) -butanone- 1, 2- (dimethylamino) -2-[(4-methylphenyl) methyl) -1- [4- (4-morphoyl) phenyl] -1-butanone, N, Acetophenones such as N-dimethylaminoacetophenone; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2 , 4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropyl Thioxanthone such as thioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-pentanthone Anthraquinones such as anthraquinone and 2-aminoanthraquinone; Acetals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; ethyl-4-dimethylamino benzyl Esters, benzoates such as 2- (dimethylamino) ethylbenzoate, ethyl p-dimethylbenzoate; 1,2-octanedione, 1- [4- (benzene Thio)-, 2- (O-benzidine oxime)], ethyl ketone, 1- [9-ethyl-6- (2-methylbenzyl) -9H-carbazol-3-yl] -, 1- (O-acetamoxime) and other oxime esters; bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole) 1-yl) phenyl) titanium, bis (cyclopentadienyl) -bis [2,6-difluoro-3- (2- (1-pyrrole-1-yl) ethyl) phenyl] titanium, etc. Dinitrocene; phenyl disulfide 2-nitropyrene, butyrol, fennel ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide and the like.

Among the above, a fluorenylphosphine oxide-based photopolymerization initiator such as a monofluorenylphosphine oxide-based photopolymerization initiator or a bisfluorenylphosphine oxide-based photopolymerization initiator has photobleaching properties , So it is better. Here, the so-called photobleaching is also called photofading or photobleaching, and refers to a reaction caused by a fluorescent substance in an excited state becoming chemically activated and unstable compared to a ground state. Specifically, it means that a compound that functions as a photopolymerization initiator absorbs light in a specific wavelength region to generate radicals. At this time, the structure of the compound changes due to the generation of free radicals, and changes in the wavelength region. It is difficult to absorb light. This allows light in this wavelength region to pass easily, so that it can be light-hardened to a deep portion. In particular, 2,4,6-trimethylbenzylidene-diphenylphosphine oxide (Omradrad TPO manufactured by IGM) and bis (2,4,6-trimethylbenzylidene) phenyl can be suitably used. Phosphine oxide (IRGACURE819 manufactured by BASF JAPAN), phenyl (2,4,6-trimethylbenzylidene) ethyl phosphinate (IRGACURE TPO-L manufactured by BASF JAPAN).

The blending amount of the photopolymerization initiator other than the oxime ester-based photopolymerization initiator is, in terms of nonvolatile components, preferably 0.1 to 30 parts by mass relative to 100 parts by mass of the resin having a carboxyl group (A). If it is 0.1 mass part or more, since the photocurability of a resin composition becomes favorable, it will become difficult to peel a film, and the film characteristics, such as chemical resistance, will also become favorable. On the other hand, if it is 30 parts by mass or less, the effect of reducing outgas can be obtained, and further, since the light absorption on the surface of the solder resist coating film becomes good, it is difficult to reduce the deep hardenability. It is more preferably 0.5 to 15 parts by mass. The blending amount of the oxime ester-based photopolymerization initiator is, in terms of nonvolatile components, preferably 0.01 to 5 parts by mass relative to 100 parts by mass of the resin containing a carboxyl group (A). When it is 0.01 parts by mass or more, since the photocurability of the resin composition is good, the film properties such as heat resistance and chemical resistance are also improved. On the other hand, if it is 5 parts by mass or less, the light absorption of the solder resist film becomes good, so that the hardening properties in the deep part are not easily reduced. It is more preferably 0.5 to 3 parts by mass.

[(C) epoxy resin]
(C) The epoxy resin contains "an epoxy resin having a biphenyl skeleton" and "an epoxy resin that is solid or semi-solid at ordinary temperature other than this". Compared with liquid epoxy resins, epoxy resins with a biphenyl skeleton and other solid or semi-solid epoxy resins at room temperature have lower solubility for development, especially for rings with a biphenyl skeleton. Oxygen resin has high crystallinity and strong hydrophobicity. Therefore, as in the present invention, it is configured and used in combination with a solid or semi-solid epoxy resin at normal temperature, so that the developer in the bottom of the opening can be reliably prevented. Soak. As a result, the occurrence of undercuts can be prevented, and excellent resolution can be obtained. Furthermore, the hardened | cured material can be excellent in the high-temperature high-humidity resistance (PCT resistance) or the outstanding cold-heat cycle resistance (TCT resistance).

As the epoxy resin having a biphenyl skeleton in the component (C), a well-known and commonly used polyfunctional epoxy resin having a biphenyl skeleton can be used. For example, a polyfunctional solid epoxy resin (NC-3000H, NC-3000, manufactured by Nippon Kayaku Co., Ltd.), a biphenyl epoxy resin (YX-4000, manufactured by Mitsubishi Chemical Co., Ltd., YL- 6121HA) and so on.

On the other hand, "the epoxy resin which is solid or semi-solid at ordinary temperature other than this at normal temperature" in (C) component can also use a well-known and usual kind. Examples of epoxy resins that are solid at normal temperature include bisphenol A epoxy resin (jER1001 manufactured by Mitsubishi Chemical Co., Ltd.), bisphenol F epoxy resin (jER4004P manufactured by Mitsubishi Chemical Co., Ltd.), and naphthalene. Type epoxy resin (HP-4700 manufactured by DIC), naphthalene skeleton-containing polyfunctional solid epoxy resin (NC-7000 manufactured by Nippon Kayaku Co., Ltd.), and triphenol epoxy resin (Nippon Kayaku Co., Ltd.) EPPN-502H), a polyfunctional solid epoxy resin containing a dicyclopentadiene skeleton (Epiclon HP-7200, manufactured by DIC), cresol novolac epoxy resin (Epiclon N-690, manufactured by DIC) ), Phenol novolac epoxy resin (Epiclon N-770, manufactured by DIC), phosphorus-containing epoxy resin (TX0712, manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), and (2,3-epoxy propane) Base) isocyanurate (TEPIC manufactured by Nissan Chemical Industry Co., Ltd.); as the semi-solid epoxy resin at room temperature, bisphenol A type epoxy resin (jER834 manufactured by Mitsubishi Chemical Co., Ltd.), naphthalene Type epoxy resin (HP-4032 manufactured by DIC).

Herein, in the present invention, the so-called solid or semi-solid at normal temperature refers to the meaning of solid or semi-solid at 15 ° C. The determination of solid or semi-solid shape can be made based on the second page of "Proof of liquid state" on the additional page of Provincial Decree (Provincial Decree No. 1 of the Heisei year) on the test of dangerous substances and properties.

(C) The blending ratio of the epoxy resin is preferably 0.5 to 2.5 mol per 1 mol of the carboxyl group contained in the resin containing the carboxyl group, and the functional group of the thermosetting component to be reacted is preferably 0.5 to 2.5 mol, and more preferably 0.8 ~ 2.0mol.

[(D) Inorganic filler]
The (D) inorganic filler constituting the curable resin composition of the present invention contains spherical silica and barium sulfate, and the mixing ratio of the spherical silica and barium sulfate is 1: (0.5 ~ 5) ). By setting the blending ratio of the spherical silica and barium sulfate to the above ranges, the function of lowering the coefficient of linear expansion (CTE) of the spherical silica can be maintained, and the function of barium sulfate can be utilized at the same time. To improve the deep hardening of the coating film and suppress undercutting.
As a result, deterioration in developability due to undercuts can be effectively prevented, and further, the high-temperature and high-humidity resistance (PCT resistance) and the cold-heat cycle resistance and heat resistance (TCT resistance) of the cured product can be improved. The blending ratio of the spherical silica and barium sulfate is preferably a volume ratio of 1: (1 to 4), and particularly preferably 1: (1.5 to 3.5).

(D) The blending amount of the inorganic filler is desirably consistent with the linear thermal expansion coefficient of the wiring board formed using the curable resin composition as much as possible. The non-volatile content of the curable resin composition is 20% by mass. The above is preferably, and more preferably 30% by mass or more. (D) The content of the inorganic filler is, based on the total of spherical silica and barium sulfate, 20% by mass or more of the non-volatile content of the curable resin composition, so that the content of the curable resin composition can be increased. The coefficient of linear expansion (CTE) becomes low, which improves TCT resistance.

[Spherical silica]
As the spherical silica, any spherical silica can be used as long as it can be used as a filler for electronic materials, and it may be used alone or in combination of two or more. The shape of the spherical silicon dioxide may be spherical, and is not limited to a true spherical shape. As a suitable spherical silica, for example, a true sphericity measured in the following manner is 0.8 or more, but it is not limited to this.

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

In the present invention, as the spherical silicon dioxide, spherical silicon dioxide having an average particle diameter of 300 nm to 1000 nm is preferably used, and the average particle diameter is more preferably set to 500 nm to 900 nm.

Here, the average particle diameter of the spherical silica in this specification is not just the particle diameter of the primary particles, but also the average particle diameter (D50) that also includes the particle diameter of the secondary particles (agglomerates). The value of D50 measured by the laser diffraction method. As a measuring device by the laser diffraction method, Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd. is mentioned. The maximum particle diameter (D100) and the particle diameter (D10) can also be measured in the same manner by the apparatus described above.

In the present invention, as the spherical silica, two types of spherical silicas having different average particle diameters can be used. That is, in addition to spherical silica having an average particle diameter of 300 nm to 1000 nm, spherical silica having an average particle diameter of 1 to 300 nm may be used in combination. By using them together, the spherical silicon dioxide having a relatively large average particle diameter is filled with spherical silicon dioxide having a small average particle diameter. Accordingly, while maintaining the characteristics originally required as a solder resist, the hardening resin composition can be further filled with spherical silica.

From the viewpoint of the closest packing property, the difference between the average particle diameter of the spherical silicon dioxide having a larger average particle diameter and the spherical silicon dioxide having a smaller average particle diameter is preferably 5 times or more. The larger the difference between the average particle diameters, the better, 8 times or more is more preferable, and 10 times or more is more preferable.

The maximum particle diameter (D100) of the spherical silica varies depending on the use of the curable resin composition. For example, when the hardened film is formed on a semiconductor package substrate, it is preferably 5 μm or less.
Furthermore, it is preferable that the particle diameter (D10) of the spherical silica with a larger average particle diameter is 5 times or more the average particle diameter (D50) of the spherical silica with a smaller average particle diameter. If the ratio is 5 times or more, the spherical silica having a smaller average particle diameter will improve the fillability of the gaps between the spherical silica having a larger average particle diameter, so that the strength of the cured product can be obtained. The balance of mechanical properties such as mechanical properties and lamination of the dry film is an excellent curable resin composition.

If the spherical silica with a large average particle size and the spherical silica with a small average particle size are used together, the blending ratio is based on the volume ratio (spherical silica with a large average particle size) : (Spherical silica with a smaller average particle diameter) = 5: 5 to 9: 1 is preferable, and 6: 4 to 8: 2 is more preferable. If it is the said range, it is preferable that the mechanical characteristics, such as the intensity | strength of hardened | cured material, and lamination | stackability of a dry film can be achieved further, and it is preferable.

The method for producing such a spherical silica is not particularly limited, and a method known to those skilled in the art can be applied. For example, it can be manufactured by burning a silicon powder by a VMC (Vaporized Metal Combustion) method. The so-called VMC method means that a chemical flame is formed by a burner in an oxygen-containing atmosphere, and a metal powder constituting part of a target oxide particle is injected into the chemical flame in an amount sufficient to form a dust cloud to cause an explosion. Method of burning to obtain oxide particles.

As commercially available spherical silicon dioxide, for the spherical silicon dioxide having a large average particle diameter, for example, SO-C2, SO-E2, SO-E3, and Denca manufactured by Admatechs may be mentioned. SFP-20M, SFP-30M, etc., for spherical silica with a small average particle diameter, for example, Admanano manufactured by Admatechs, SO-E1, UFP-30 manufactured by Denca, and Japan Touch Seahostar series made by media (stock), Sciqas series made by Sakai Chemical Industry (stock), SG-SO100 made by KCM Corporation (stock), and the like.

In order to maintain high dispersibility even with a large amount of filling, it is preferable to apply a surface treatment to the spherical silica. Aggregation can be suppressed by applying a surface treatment. If spherical silica with a larger average particle size and spherical silica with a smaller average particle size are used in combination as spherical silica, only one of them may be surface-treated, or Surface treatment was applied to both.

The surface treatment method of the spherical silica is not particularly limited, and a well-known and commonly used method may be used, and a surface treatment agent having a hardening reactive group (for example, a coupling agent having an organic group as a hardening reactive group) The surface of the inorganic filler is preferably treated.

As the coupling agent system, coupling agents such as a silane system, a titanate system, an aluminate system, and a zirconium aluminate system can be used. Among them, a silane-based coupling agent is preferred. Examples of the silane-based coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, and N- (2-aminomethyl) -3-aminopropylmethyldimethoxy. Silane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinepropyltrimethoxysilane, 3-cyclo Oxypropoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3- Methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like may be used alone or in combination. Such a silane-based coupling agent is preferably immobilized by adsorbing on the surface of the spherical silica in advance or by reaction. Here, the processing amount of the coupling agent with respect to 100 parts by mass of the spherical silica is preferably 0.5 to 10 parts by mass. In the present invention, the reactive functional group derived from the coupling agent applied to the spherical silica does not include a compound having a photocurable reactive group and a thermosetting functional group.

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

Examples of the thermosetting reactive group include a hydroxyl group, a carboxyl group, an isocyanate group, an amine group, an imino group, an epoxy group, an oxetanyl group, a mercapto group, a methoxymethyl group, a methoxyethyl group, and an ethyl group. Oxymethyl, ethoxyethyl, oxazoline and the like. Among them, at least any one of an amine group and an epoxy group is preferred.

The surface-treated spherical silica may be contained in the curable resin composition of the present invention in a surface-treated state, and the surface-untreated spherical silica and the surface may be separately prepared. As the treatment agent, spherical silica is surface-treated in the composition, but it is preferable to prepare spherical silica with surface treatment in advance. By preparing spherical silicon dioxide that has been surface-treated in advance, it is possible to suppress a decrease in crack resistance and the like due to a surface treatment agent that is not consumed in the surface treatment that may remain at the time of each preparation. When the surface treatment is performed in advance, it is preferable to prepare a preliminary dispersion liquid in which the spherical silica is prepared to be dispersed in a solvent or a hardening component; and it is more preferable that the spherical silica in which the surface treatment is prepared is dispersed in The pre-dispersion is prepared in the solvent in the composition, or after the surface untreated spherical silica is pre-dispersed in the solvent, sufficient surface treatment is performed, and then the pre-dispersion is prepared in the composition. in.

Spherical silica based on the use state of the curable resin composition of the present invention can be formulated in the powder or solid state with the component (A), etc., or can be mixed with a solvent or dispersant to form a slurry. And (A) component.

[Barium sulfate]
As the barium sulfate, any known species may be used, and at least one selected from the group consisting of hydroxides and oxides of metal elements may be coated on barium sulfate for surface treatment. The metal elements are One or more selected from Al, Si, and Zr. Specific examples of the surface treatment agent include hydrous silicic acid, hydrous amorphous silica, aluminum hydroxide, zirconia, and an organic silane-based compound.
As such commercially available products of barium sulfate, for example, precipitable barium sulfate 制 100, precipitable barium sulfate 制 300, precipitable barium sulfate SS-50, BARIACE B-30, BARIACE manufactured by Sakai Chemical Industry Co., Ltd. B-31, Bariace B-32, Bariace B-33, Bariace B-34, Barifine BF-1, Barifine BF-10, Barifine BF-20, Barifine BF-40, W-1 manufactured by Takehara Chemical Industry Co., Ltd. , W-6, W-10, C-300, etc. Among these, one type may be used alone, or two or more types may be used in combination.

The barium sulfate is preferably pH 4.0 to 9.0, and more preferably 5.0 to 9.0.

The average particle size of barium sulfate is preferably 0.1 to 1 μm, and more preferably 0.1 to 0.5 μm.

In the curable resin composition as described above, a photopolymerizable monomer or a thermosetting catalyst, a colorant, an organic solvent, and other additional components may be blended.
[Photopolymerizable monomer]
In the curable resin composition of the present invention, a photopolymerizable monomer can be blended. The photopolymerizable monomer is a compound having an ethylenically unsaturated double bond. Examples of such photopolymerizable monomers include alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate; (meth) acrylic acid (Hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl ester, 2-hydroxypropyl (meth) acrylate, and the like; alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol) Mono- or di (meth) acrylates; hexanediol, trimethylolpropane, pentaerythritol, bis (trimethylol) propane, dipentaerythritol, polyhydroxy ethyl isocyanurate, or the like Polyvalent (meth) acrylates such as ethylene oxide or propylene oxide adducts; phenoxyethyl (meth) acrylate, polyethoxydi (meth) acrylate of bisphenol A (Meth) acrylates of phenols such as ethylene oxide or propylene oxide adducts; glycerol diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate (Meth) acrylates of glycidyl ethers such as acid esters; and melamine (meth) acrylates.

A photopolymerizable single system may be used individually by 1 type, or may be used in combination of 2 or more type. The content of the photopolymerizable monomer is preferably 0.5 to 20 parts by mass based on 100 parts by mass of the resin having a carboxyl group (A). When the blending amount is 0.5 parts by mass or more, the photocurability is good, and thus pattern formation can be easily performed in alkali development after active energy ray irradiation. On the other hand, if it is 20 parts by mass or less, halo is less likely to occur and good resolvability can be obtained.

[Heat hardening catalyst]
In the curable resin composition of the present invention, a thermosetting catalyst can be blended. Examples of the thermosetting catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, and 1-cyano Imidazole derivatives such as ethyl-2-phenylimidazole, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamine, benzyldimethylamine, 4- (Dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, 4-methyl-N, N-dimethylbenzyl Amine compounds such as amines, hydrazine compounds such as dihydrazine adipate, dihydrazine adipate, and phosphorus compounds such as triphenylphosphine. In addition, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloxyethyl-S-triazine, 2-vinyl-2 can also be used 2,4-diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine, isocyanuric acid adduct, 2,4-diamino-6-methyl S-triazine derivatives such as acryloxyethyl-S-triazine and isocyanuric acid adducts are preferably compounds which can also function as adhesion-imparting agents for curing with heat Catalysts are used in combination.

The thermosetting catalyst system can be used alone or in combination of two or more. The blending amount of the thermosetting catalyst is preferably 0.5 to 20 parts by mass, and more preferably 1 to 15 parts by mass, with respect to 100 parts by mass of the nonvolatile component of the resin containing the carboxyl group (A). If it is 0.5 mass part or more, heat resistance will be excellent. When it is 20 parts by mass or less, it is related to improvement of storage stability.

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

Specifically, the number of C.I. (issued by the Society of Dyers an Colourists) number is mentioned.

Examples of red colorants include monoazo, diazo, azo lake, benzimidazolone, hydrazone, diketopyrrole, condensed azo, anthraquinone, and quinacridone. Wait. Examples of the blue colorant include phthalocyanin-based, anthraquinone-based, and the like, and pigment-based compounds can be used as pigments. In addition to these, metal-substituted or unsubstituted phthalocyanin compounds may be used. As the green colorant, there are phthalocyanin-based, anthraquinone-based, and fluorene-based. In addition to these, metal-substituted or unsubstituted phthalocyanin compounds may be used. Examples of the yellow colorant include monoazo-based, disazo-based, condensed azo-based, benzimidazolone-based, isoindolinone-based, and anthraquinone-based. Examples of the white colorant include rutile-type or anatase-type titanium oxide. Examples of black colorants include carbon black, black lead, iron oxide, titanium black, anthraquinone, cobalt oxide, copper oxide, manganese, antimony oxide, nickel oxide, samarium, aniline, and sulfur. Molybdenum, bismuth sulfide, etc. In addition, according to the purpose of adjusting color tone, purple, orange, brown and other coloring agents can also be added.

The content of the coloring agent is preferably 0.18 to 0.50% by mass in terms of solid content conversion with respect to the entire amount of the curable resin composition in terms of improving the concealment of the cured product. When the solid content is 0.18% by mass or more, the circuit concealability is excellent, and when it is 0.50% by mass or less, the resolution is more excellent. It is more preferably 0.20% by mass to 0.40% by mass.

[Organic solvents]
When the composition is prepared or applied to a substrate or a film, the curable resin composition of the present invention may contain an organic solvent for the purpose of adjusting the viscosity and the like. As the organic solvent, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, Carbitol, methylcarbitol, butylcarbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, tripropylene glycol Glycol ethers such as monomethyl ether; ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol Esters of acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, propylene carbonate, etc .; aliphatic hydrocarbons such as octane, decane; petroleum ether, petroleum naphtha, solvents Well-known and commonly used organic solvents such as petroleum-based solvents such as petrolatum. These organic solvents may be used alone or in combination of two or more.

[Other optional ingredients]
According to the requirements, the curable resin composition of the present invention may further be formulated with a photoinitiator, a cyanate compound, an elastomer, a mercapto compound, a urethane catalyst, a thixotropic agent, and an adhesion promoter. , Block copolymers, chain transfer agents, polymerization inhibitors, copper inhibitors, antioxidants, rust inhibitors, micronized silica, organic bentonite, thickeners such as microcrystalline kaolinite, polysiloxanes, fluorine Based, polymer based defoamers and / or leveling agents, silane coupling agents such as imidazole, thiazole, and triazole, phosphorous compounds such as phosphites, osmates, and phosphazene compounds And other components such as flame retardants. These systems are well known in the field of electronic materials.

The curable resin composition of the present invention may be used in a dry form, or may be used in a liquid form. Moreover, when it is liquid, it may be a single liquid or two or more liquids.

The curable resin composition of the present invention is useful as a pattern layer for forming a permanent film of a printed wiring board such as a solder resist, a cover film, and an interlayer insulating layer, 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 with a thin film, and is therefore suitable for use in printed wiring boards that require thinning, such as semiconductor package substrates (used in semiconductor packages). Formation of patterned layers in printed wiring boards). Furthermore, the cured product obtained from the curable resin composition of the present invention is suitable for use in semiconductor packages that require fine pattern formation or high-density mounting, even in terms of resolvability and excellent thermal dimensional stability. Formation of a permanent coating in a substrate.

(Dry film)
The curable resin composition of the present invention may be in the form of a dry film, and includes a support (carrier) film and a dried resin layer formed of the curable resin composition formed on the support film. . When dry filming is performed, the above-mentioned organic solvent is used to dilute the curable resin composition of the present invention and adjust it to an appropriate viscosity, and apply comma coating, doctor blade coating, lip and mouth coating, rod coating, and pressure roller coating. Cloth, reverse roll coating, transfer roll coating, gravure coating, spray coating, etc., are applied to the support film with a uniform thickness, and generally dried at a temperature of 50 to 130 ° C for 1 to 30 minutes. Thus, a film can be obtained. There is no particular limitation on the thickness of the coating film, but the film thickness after drying is usually 1 to 150 μm, preferably 10 to 60 μm, and is appropriately selected.

As the supporting film, a plastic film can be used, and a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyimide film, a polypropylene film, and a polystyrene can be used. Plastic films such as films are preferred. There is no particular limitation on the thickness of the support film, but it is usually appropriately selected in the range of 10 to 150 μm.

After the resin layer of the curable resin composition of the present invention is formed on a support film, in order to prevent foreign matter from adhering to the surface of the resin layer, a protective (covering) film that can be peeled off is laminated on the surface of the resin layer. good. As a peelable protective film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used. When peeling the protective film, compared with the adhesion between the resin layer and the support film, as long as The adhesive force between the resin layer and the protective film may be small.

In the present invention, a resin layer may be formed by applying the curable resin composition of the present invention on the protective film and drying it, and a support film may be laminated on the surface. That is, in the production of the dry film in the present invention, as the film to which the curable resin composition of the present invention is applied, any of a support film and a protective film may be used.

(Hardened)
The cured product of the present invention is obtained by curing the curable resin composition of the present invention or the resin layer of the dry film of the present invention, and therefore has excellent resolvability and thermal dimensional stability.

(Printed wiring board)
The printed wiring board of this invention is a hardened | cured material obtained from the resin layer of the curable resin composition or dry film of this invention. As a method for manufacturing a printed wiring board of the present invention, for example, the curable resin composition of the present invention is adjusted to a viscosity suitable for a coating method by using the above-mentioned organic solvent, and the dip coating method and flow coating are used. Method, roll coating method, rod coating method, screen printing method, curtain coating method, etc. After coating onto the substrate, the organic solvent contained in the composition is evaporated to dryness at a temperature of 60 to 100 ° C. (Temporarily dried), thereby forming a non-stick resin layer. In the case of a dry film, a resin layer is formed on the base material by laminating the support film to the base material with a bonding machine or the like so that the resin layer is in contact with the base material.

As the substrate, in addition to a printed wiring board or a flexible printed wiring board in which a circuit is formed by copper in advance, paper-phenol, paper-epoxy, glass cloth epoxy, glass polyimide, Materials such as glass cloth / non-woven epoxy, glass cloth / paper-epoxy, synthetic fiber epoxy, fluororesin, polyethylene, polyphenylene ether, polyphenylene ether, cyanate, etc. All grades (FR-4, etc.) of copper-clad laminates, other, metal substrates, polyimide films, polyethylene terephthalate films, polyethylene naphthalate (PEN) films , Glass substrate, ceramic substrate, wafer plate, etc.

After volatilizing drying after coating the curable resin composition of the present invention, a hot-air circulation drying oven, an IR oven, a heating plate, a convection heating oven, etc. can be used (those who use a heat source with air heating by steam, The method of contacting the hot air in the dryer with countercurrent flow and the method of spraying the support by a nozzle) are performed.

After the resin layer is formed on the substrate, a photomask with a predetermined pattern is formed, and exposure is performed by selective active energy rays. Sodium hydroxide solution) to develop a pattern of a cured product. Furthermore, the hardened object is irradiated with active energy rays and then heat-cured (for example, 100 to 220 ° C.), or after heating and hardening, the active energy rays are irradiated, or only by heat-curing to finally complete hardening (main hardening), thereby forming Various properties such as adhesion and hardness are excellent cured films.

The exposure machine used in 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 halide lamp, a mercury short-arc lamp, and the like, and irradiates ultraviolet rays in the range of 350 to 450 nm, and may also Use a direct rendering device (such as a laser direct imaging device that draws an image with a direct laser by CAD data from a computer). The lamp light source or laser light source used as the direct drawing machine is preferably in a range of a maximum wavelength of 350 to 450 nm. The exposure amount used for image formation varies depending on the film thickness and the like, but it is usually 10 to 1000 mJ / cm ² , and preferably it can be set in the range of 20 to 800 mJ / cm ² .

As the developing method, a dipping method, a rinsing method, a spray method, a brush method, and the like can be used. As a developing solution system, potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, and ammonia can be used. , Amines and other alkaline aqueous solutions.

The curable resin composition of the present invention can be used not only for applications in which a pattern of a cured film is formed by using a developer as described above, but also for applications where no pattern is formed, such as a stamper application (sealing application). ).

[Example]

Hereinafter, the present invention will be described in more detail through examples and comparative examples, but the present invention is not limited by these examples and comparative examples. However, the following indicates "parts" and "%", unless otherwise stated, all are quality standards.

(Synthesis of photosensitive resin varnish A containing carboxyl group)
Into an autoclave equipped with a thermometer, a nitrogen introduction device, an alkylene oxide introduction device, and a stirring device, a novolac type cresol resin (trade name "Shonol CRG951", manufactured by Showa Denko Corporation, OH equivalent: 119.4) 119.4 Parts by mass, 1.19 parts by mass of potassium hydroxide, and 119.4 parts by mass of toluene, the inside of the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 parts by mass of propylene oxide was slowly added dropwise, and reacted at 125 to 132 ° C. and 0 to 4.8 kg / cm ² for 16 hours. After that, the mixture was cooled to room temperature, and 1.56 parts by mass of 89% phosphoric acid was added to the reaction solution to neutralize potassium hydroxide, thereby obtaining 62.1% nonvolatile matter and a hydroxyl value of 182.2 mgKOH / g (307.9 g / eq.). A propylene oxide reaction solution of a novolac type cresol resin. This phenolic hydroxyl group has an average of 1.08 moles of alkylene oxide per 1 equivalent.
293.0 parts by mass of the obtained novolac 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 equipped mixer In a reactor using a thermometer, an air blowing tube, air was blown in at a rate of 10 ml / min, and the reaction was performed at 110 ° C. for 12 hours while stirring. The water system produced by the reaction was used as an azeotropic mixture with toluene, and 12.6 parts by mass of water was distilled off. After that, it was cooled to room temperature, and the obtained reaction solution was neutralized with 35.35 parts by mass of a 15% sodium hydroxide aqueous solution, followed by washing with water. Thereafter, toluene was replaced with 118.1 parts by mass of diethylene glycol monoethyl ether acetate by an evaporator, and distilled off to obtain a novolac type acrylate resin solution. Next, 332.5 parts by mass of the obtained novolak type acrylate resin solution and 1.22 parts by mass of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer, and an air blowing tube, and air was added at 10 ml / min. The mixture was blown at a high speed, 60.8 parts by mass of tetrahydrophthalic anhydride was slowly added while stirring, and the mixture was reacted at 95 to 101 ° C. for 6 hours, and then taken out after cooling. In such a manner, a solution of a photosensitive carboxyl group-containing resin having a nonvolatile content of 70.6% by mass and an acid value of a solid of 87.7 mgKOH / g was obtained.

<Preparation of curable resin composition>
Each component was prepared according to the formulation shown in Tables 1 and 2 below, and after pre-mixing by a stirrer, it was dispersed and kneaded with a 3-roll mill to prepare a curable resin composition, respectively. The blending amount in the table indicates parts by mass. The obtained examples and comparative examples were used, and evaluation was performed as follows.

＜ Production of dry film ＞
The curable resin compositions of Examples and Comparative Examples were each appropriately diluted with methyl ethyl ketone, and then applied to a PET film (manufactured by Toray Co., Ltd.) so that the film thickness after drying was 15 μm using an applicator. , FB-50, thickness 16 μm), and dried at 80 ° C. for 30 minutes to obtain a dry film.

＜ Method of making evaluation board ＞
Using a vacuum laminator (CVP-300 manufactured by Nikko-Materials), the dry film produced by the above method was heated to form a pressure under the conditions of pressure: 0.4 MPa, 80 ° C, 1 minute, and vacuum: 3 hPa. A printed wiring board having a chemically polished (MEC (stock) CZ-8101) copper circuit was subjected to flat pressing at 70 ° C and 0.5 MPa to obtain a printed substrate having an unexposed solder resist layer (dry film). This substrate was exposed using a mask of φ80 μm and an exposure device equipped with a high-pressure mercury lamp (short arc lamp) at a standard exposure amount, and the PET film was peeled off. Thereafter, a 1% by mass Na ₂ CO ₃ aqueous solution was used at 30 ° C., and development was performed under conditions of a spray pressure of 2 kg / cm ² for 60, 90, and 120 seconds, respectively, to obtain a substrate having a film formed by patterning. This substrate was irradiated with ultraviolet rays under a condition of a cumulative exposure of 1000 mJ / cm ^{2 in} a UV conveyor furnace, and then heated at 160 ° C. for 60 minutes to harden the film.

＜ Analytical Evaluation ＞
The size of the developer infiltration (undercut) at the bottom of the opening pattern of φ80 μm of the evaluation substrate obtained by the above method was evaluated by cross-sectional observation.
：: No undercut was found.
○: Undercut is less than 5 μm.
△: The undercut is 5 to 10 μm.
× ₁ : Undercut exceeds 10 μm.
× ₂ : There is a residue in the opening.

＜ Evaluation of PCT resistance ＞
Using an PCT device (HAST SYSTEM TPC-412MD manufactured by ESPEC), the evaluation substrate obtained by the above method was subjected to a PCT (Pressure Cooker Test) for 168 hours under conditions of 121 ° C, saturation, and 0.2 MPa. Moreover, the state of the coating film after PCT was evaluated. The determination criteria are as follows.
○: No swelling, peeling, discoloration, or dissolution.
△: Swelling, peeling, discoloration, or dissolution were found.
×: Many swelling, peeling, discoloration, and dissolution were found.

＜ Evaluation of TCT resistance ＞
By the same method as the above-mentioned evaluation substrate, a hardened film having a mounting pattern of a Si wafer is formed on the packaging substrate. Thereafter, the substrate was subjected to an Au plating process, a solder bump was formed, and a Si wafer was mounted to obtain a TCT evaluation substrate.
The TCT evaluation substrate obtained as described above was placed in a hot and cold cycler, which performs TCT by performing temperature cycling between -65 ° C and 150 ° C. The surface of the cured film was observed at 600 cycles, 800 cycles, and 1000 cycles. The determination criteria are as follows.
：: No abnormality at 1000 cycles.
○: No abnormality at 800 cycles, and cracks occurred at 1000 cycles.
△: No abnormality at 600 cycles, and cracks occurred at 800 cycles.
×: Cracks occurred at 600 cycles.

These evaluation results are combined and shown in the following table.

＊ 1: Varnish A synthesized above (non-volatile content 70.6%)
＊ 2: Omnirad TPO (manufactured by IGM, 2,4,6-trimethylbenzylidene-diphenylphosphine oxide)
＊ 3: jER834 (Mitsubishi Chemical Co., Ltd., bisphenol A epoxy resin (semi-solid epoxy equivalent at normal temperature 250)
＊ 4: NC-3000H (manufactured by Nippon Kayaku Co., Ltd., biphenyl-phenol type epoxy resin (solid epoxy equivalent at normal temperature is 290)
＊ 5: jER828 (Mitsubishi Chemical Co., Ltd., bisphenol A epoxy resin (liquid epoxy equivalent 190 at normal temperature)
＊ 6: SFP-30M (Denca (strand), spherical silica, average particle diameter 0.8 μm, specific gravity 4.4 g / cm ³ )
＊ 7: BRIACE B-31 (manufactured by Sakai Chemical Industry Co., Ltd., barium sulfate, amorphous, average particle size 0.3 μm, specific gravity 2.2 g / cm ³ )
＊ 8: DPHA (manufactured by Nippon Kayaku Co., Ltd., dipentaerythritol pentaacrylate)
＊ 9: Melamine (made by Nissan Chemical Industries, Ltd.)
＊ 10: DICY (manufactured by Mitsubishi Chemical Co., Ltd., dicyandiamine)

From the evaluation results shown in the above table, it is clear that in each of the examples, degradation of the resolution due to undercuts during development is not easy, and high temperature and high humidity resistance (PCT resistance) or cold and heat cycle resistance can be obtained (TCT resistance) is an excellent cured product.

Claims (5)

A hardening resin composition containing: (A) a carboxyl group-containing resin, (B) photopolymerization initiator, (C) Epoxy resin and (D) an inorganic filler characterized by, The epoxy resin (C) includes an epoxy resin having a biphenyl skeleton and an epoxy resin that is solid or semi-solid at ordinary temperatures other than that, The inorganic filler (D) contains spherical silica and barium sulfate, and the mixing ratio of the spherical silica and the barium sulfate is 1: (0.5 to 5) in volume ratio. The curable resin composition according to claim 1, wherein the (B) photopolymerization initiator includes a fluorenylphosphine oxide-based polymerization initiator. A dry film comprising a resin layer obtained from the curable resin composition of claim 1. A cured product obtained by curing a resin layer made of a curable resin composition of claim 1 or 2 or a dry film of claim 3 of a dry film. A printed wiring board having a hardened body according to claim 4.