JP2020166215A - Dry film, cured product and electronic component - Google Patents

Abstract

To provide a dry film having a resin layer obtained from a photosensitive resin composition excellent in resolution, handling property and cold-heat shock resistance of a cured product.SOLUTION: The dry film includes: a film; and a photosensitive resin layer disposed on one surface of the film and having a thickness of 3 to 13 μm and an absorbance of 0.5 to 1.5 for light at a wavelength of 365 nm. The photosensitive resin layer comprises (A) a curable copolymer resin having at least a first repeating unit that is a maleimide derivative and a second repeating unit that is a (meth)acrylate derivative having a thermal crosslinking group in a side chain, (B) a photopolymerization initiator, (C) a thermosetting resin, and (D) an inorganic filler.SELECTED DRAWING: None

Description

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

A dry film having a resin layer made of a photosensitive resin composition used for forming an insulating material such as a solder resist in the production of a printed wiring board has been developed (for example, Patent Document 1). In recent years, there has been an increasing demand for miniaturization and thinning of electronic components, and solder resists and the like are also required to be further thinned and miniaturized in patterns.

For example, in recent years, the number of IOs has been increasing due to the high density of semiconductor packages and the increase in the number of large dies due to the high performance of electronic devices. Especially for substrates with a low profile structure, the surface layer pattern is miniaturized (L). Along with the narrowing of the / S value), the diameter of the opening of the insulating material provided on the pad for connecting parts is also being reduced. In such a tendency, it becomes difficult to secure a sufficient amount of solder required for mounting the die. Therefore, there is a demand for a technique that minimizes the gap between the substrate and the die by reducing the thickness of the insulating material and enables the connection reliability to be ensured even with a small amount of solder.
On the other hand, there are some electronic components in which a photosensitive resin composition is applied onto a silicon wafer and applied to a sensor module. Even in such electronic components, a photosensitive resin composition capable of forming a thin film and having excellent resolution is required.

Japanese Unexamined Patent Publication No. 2012-123394

In the low profile structure, for example, in the case of a solder resist, there is a demand for a thin film of 3 to 13 μm, which is about half of the conventional thickness (15 to 25 μm on the conductor circuit). Further, in the low-profile structure, the pad for connecting parts is also small, so that resolution is also required so that an opening having a considerably small diameter such as 30 μm in diameter can be formed.

However, when an attempt is made to make a thin film using a conventional photosensitive resin composition, in addition to the large influence of halation due to refraction of light at the interface between the inorganic filler component and the resin component during exposure, active energy rays are generated. Increases the transparency of. Therefore, the opening is overhanged, that is, the upper part of the opening is developed into a narrowed shape, and it is difficult to form a small-diameter opening in which the overhang is suppressed, which causes a problem in resolution. .. Therefore, a composition that does not contain an inorganic filler as in the photosensitive resin composition described in Patent Document 1 is one means for thinning the film. However, if the inorganic filler is not added, the die or conductor Since the CTE (coefficient of thermal expansion) difference from the layer becomes large, there is a problem that the thermal shock resistance is not sufficient and cracks occur. In particular, in the low profile structure, since the distance to the die is short, the influence of the CTE difference from the die is large, and the thermal shock resistance is further lowered. That is, in thinning, there is a problem of antinomy between resolution and thermal shock resistance.

Further, the thinner the resin layer of the dry film, the lower the handleability of the dry film, which causes problems such as the resin layer cracking and powder falling off during slit processing.

Therefore, an object of the present invention is a dry film having a resin layer obtained from a photosensitive resin composition having excellent handleability, resolution, and cold shock resistance of a cured product, and a cured product of the resin layer of the dry film. An object of the present invention is to provide an electronic component having the cured product.

As a result of diligent studies toward the realization of the above object, the present inventor has blended a curable resin having a specific structure with a photopolymerization initiator, a thermosetting resin and an inorganic filler, and further has a specific absorbance. We have found that the above-mentioned problems can be solved by forming layers, and have completed the present invention.

（式中、Ｒ_０は、炭素数１〜３０の１価の有機基であり、Ｒ_１は、水素原子あるいは炭素数１〜７の有機基であり、Ｒ_２は、単結合あるいは炭素数１〜５のアルキレン基であり、Ｒ_３は、熱架橋性を有する１価の基を表す。） That is, the dry film of the present invention comprises a film and a photosensitive resin layer provided on one surface of the film and having a thickness of 3 to 13 μm and a light wavelength of 365 nm and an absorbance of 0.5 to 1.5. The dry film to be provided, wherein the photosensitive resin layer has (A) at least a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2). It is characterized by containing a sex copolymer resin, (B) a photopolymerization initiator, (C) a thermosetting resin, and (D) an inorganic filler.

(In the formula, R ₀ is a monovalent organic group having 1 to 30 carbon atoms, R ₁ is a hydrogen atom or an organic group having 1 to 7 carbon atoms, and R ₂ is a single bond or 1 carbon number. It is an alkylene group of ~ 5, and R ₃ represents a monovalent group having thermocrosslinkability.)

In the dry film of the present invention, the double bond equivalent of the organic component excluding the inorganic filler (D) and the organic solvent from the photosensitive resin layer is 500 to 1,000 g / eq. Is preferable.

In the dry film of the present invention, the inorganic filler (D) is preferably 5 to 80% by mass in the photosensitive resin layer.

In the dry film of the present invention, it is preferable that the inorganic filler (D) is surface-treated.

In the dry film of the present invention, it is preferable that the photosensitive resin layer further contains (E) an elastomer.

The dry film of the present invention preferably has a residual solvent amount of 0.4 to 1.5% by mass.

The cured product of the present invention is characterized in that it is obtained by curing the photosensitive resin layer of the dry film.

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

According to the present invention, a dry film having a resin layer obtained from a photosensitive resin composition excellent in handleability, resolution, and cold impact resistance of the cured product, a cured product of the resin layer of the dry film, and , An electronic component having the cured product can be provided.

The dry film of the present invention (hereinafter, also simply referred to as "the dry film of the present invention") is provided on one surface of the film and the film, has a thickness of 3 to 13 μm, and has an absorbance of 0.5 to 365 nm. A dry film comprising a photosensitive resin layer of 1.5, wherein the photosensitive resin layer is (A) at least a first repeating unit represented by the formula (1) and the formula (2). A curable copolymer resin having a second repeating unit represented by (hereinafter, also simply referred to as "(A) curable copolymer resin"), (B) photopolymerization initiator, (C) thermosetting resin, And (D) it is characterized by containing an inorganic filler.
In the present invention, in the photosensitive resin layer having a thickness of 3 to 13 μm, it is important that the absorbance at a light wavelength of 365 nm is 0.5 to 1.5, and if it is less than 0.5, the resolution deteriorates. .. In the case of the conventional photosensitive resin composition, when the thickness is 3 to 13 μm, the absorbance is less than 0.5. In the case of the conventional film thickness, the absorbance was designed to be low in order to increase the permeability in order to cure to a deep part. However, in the present invention, since it is a thinner film than the conventional one, deep curability can be obtained even if the absorbance is designed to be high, and the resolution is excellent. However, if the absorbance exceeds 1.5, the resolution is impaired.
Although the detailed mechanism is not clear, the absorbance can be determined by blending (A) a curable copolymer resin and combining the components (B) to (D) in a photosensitive resin layer having a thickness of 3 to 13 μm. It is considered that by setting the range to a specific range, although the (D) inorganic filler was blended, the absorbance was suppressed and a pattern having excellent resolvability could be formed. Normally, a photopolymerization initiator having a high molar extinction coefficient is used to increase the photosensitivity, but in the present invention, the absorbance can be set in a specific range by appropriately combining all the components (A) to (D). It is considered that the photosensitivity was improved by the above. Further, in such a photosensitive resin layer, the thermal shock resistance can be improved by using (A) a curable copolymer resin having a maleimide structure of the formula (1) and (D) an inorganic filler in combination. .. Further, in the present invention, the handleability of the dry film can be improved.

As a method for adjusting the absorbance of the photosensitive resin layer at a light wavelength of 365 nm, the above components (A) to (D) may be combined so as to fall within the above range by a known and commonly used method. The absorbance is preferably 0.7 to 1.2, and the shape becomes particularly excellent in terms of resolution.

In the present invention, the double bond equivalent of the components obtained by removing the organic solvent from the photosensitive resin layer is 500 to 1,000 g / eq. Is preferable. Generally, the cured film formed on a silicon wafer is thin, and stress release occurs when the organic solvent used for cleaning permeates due to the generation of internal stress caused by the anchor effect, CTE mismatch, and curing shrinkage due to the photosensitive reaction. There was a problem that cracks caused by solvent cracks) and cold cycles were generated.
However, solvent cracks can be suppressed by setting the double bond equivalent within the above specific range. Although the detailed mechanism is not clear, it is considered that the solvent cracks were caused by the increase in the curing shrinkage stress due to the excessive degree of photocuring in the deep part due to the thinning, and the release of the stress by cleaning with a solvent. It is considered that the solvent crack was suppressed by setting the double bond equivalent of the photosensitive resin layer within the above-mentioned specific range.

Further, in the present invention, it is preferable that silica is blended in the photosensitive resin layer in an amount of 5% by mass or more as the (D) inorganic filler, and more sufficient thermal shock resistance can be obtained. Further, in the present invention, when the blending amount of silica is increased, for example, even if it is 30% by mass or more, the adverse effect due to light scattering is suppressed, and the resolution, the thermal shock resistance of the cured product, and the solvent crack resistance are improved. An excellent photosensitive resin layer can be formed.

Further, the inorganic filler (D) is preferably surface-treated, has good wettability with the resin component, is hard to crack even though the resin layer is thin, and is excellent in handleability. In addition, the resolution and the resistance to thermal shock and solvent crack of the cured product are also improved.

Further, from the viewpoint of handleability, the residual solvent amount of the photosensitive resin layer of the dry film is preferably 0.4 to 1.5% by mass, and it is difficult to crack even though it is thin. More preferably, it is 0.5 to 1.2% by mass. The higher the amount of residual solvent, the lower the viscosity of the dry film during laminating, so that the flowability is improved and the laminating property on the circuit substrate is improved.

Hereinafter, each component contained in the photosensitive resin layer of the dry film of the present invention will be described.

((A) Curable copolymer resin)
The photosensitive resin layer of the dry film of the present invention has (A) at least a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2). Contains a polymer resin.

（式（１）中、Ｒ_０は、炭素数１〜３０の１価の有機基であり、式（２）中、Ｒ_１は、水素原子あるいは炭素数１〜７の有機基であり、Ｒ_２は、単結合あるいは炭素数１〜５のアルキレン基であり、Ｒ_３は、熱架橋性を有する１価の基を表す。）なお、１価の有機基とは、炭素原子を有する１価の基を意味する。

(In the formula (1), R ₀ is a monovalent organic group having 1 to 30 carbon atoms, and in the formula (2), R ₁ is a hydrogen atom or an organic group having 1 to 7 carbon atoms, and R Reference numeral ₂ is a single bond or an alkylene group having 1 to 5 carbon atoms, and R ₃ is a monovalent group having a thermocrosslinkability.) The monovalent organic group is a monovalent group having a carbon atom. Means the basis of.

In the above formula (1), the monovalent organic group having 1 to 30 carbon atoms that can be taken by R ₀ is an alkyl group having 1 to 30 carbon atoms such as a methyl group, an ethyl group, an isopropyl group and a lauryl group; a phenyl group. Hydroxyphenyl group; alkylaryl group having 7 to 30 carbon atoms such as 2-methylphenyl group and 2,6-diethylphenyl group; alkoxyaryl group having 7 to 30 carbon atoms such as 2-methoxyphenyl group; benzyl group and the like Aralkyl group having 7 to 30 carbon atoms; cycloalkyl group having 3 to 30 carbon atoms such as cyclohexyl group; 2-chlorophenyl group, 2,4,6-trichlorophenyl group, 2,4,6-tribromophenyl An aryl halide group having 1 to 30 carbon atoms such as a group; an alkoxysilylalkyl group having 1 to 30 carbon atoms such as an N- [3- (triethoxysilyl) propyl] group; and 1 carbon number such as a dodecenyl group and an octadecenyl group. Examples thereof include ~ 30 alkenyl groups and carboxyl groups. The monovalent organic group having 1 to 30 carbon atoms that can be taken by R ₀ can have 20 or less carbon atoms, 15 or less carbon atoms, 10 or less carbon atoms, or 7 or less carbon atoms.

In the formula (1), R ₀ is preferably an organic group having 1 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms, a phenyl group, an alkylaryl group having 7 to 30 carbon atoms, and 3 carbon atoms. It is preferably a cycloalkyl group of ~ 30 or an aralkyl group having 7 to 30 carbon atoms.

In the formula (2), R ₁ is preferably a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, a phenyl group, an alkenyl group having 1 to 7 carbon atoms, or a carboxyl group, and is preferably a hydrogen atom or a carboxyl group. It is more preferably an alkyl group having 1 to 5 carbon atoms.

In the above formula (2), the alkylene group having 1 to 5 carbon atoms that can be taken by R ₂ may have a substituent. Examples of the alkylene group having 1 to 5 carbon atoms include a methylene group, an ethylene group, an n-propylene group, a trimethylene group and a butylene group. Examples of the substituent include a hydroxyl group and the like.

In the formula (2), examples of the monovalent group having thermal crosslinkability represented by R ₃ include a hydroxyl group, a carboxyl group, an amino group, and a thiol group. R ₃ is preferably a hydroxyl group.

The curable copolymer resin (A) requires a structural unit derived from the maleimide-based monomer represented by the formula (1) and a structural unit derived from the unsaturated carboxylic acid ester monomer represented by the formula (2) as essential units. It has as. The curable copolymer resin (A) may have a structural unit derived from an unsaturated carboxylic acid monomer or the like, if necessary, and may contain a monomer having a functional group capable of reacting with a carboxyl group. It may have a structure formed by reacting. The first repeating unit represented by the formula (1) is a maleimide-based monomer, that is, a repeating unit derived from a maleimide or a maleimide derivative.

Examples of the maleimide or maleimide derivative (hereinafter, also referred to as “maleimide-based monomer”) include N-phenylmaleimide, N- (2-methylphenyl) maleimide, N- (4-methylphenyl) maleimide, and N- (2). , 6-diethylphenyl) maleimide, N- (2-chlorophenyl) maleimide, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, N-phenyl Methylmaleimide, N- (2,4,6-tribromophenyl) maleimide, N- [3- (triethoxysilyl) propyl] maleimide, N-octadecenylmaleimide, N-dodecenylmaleimide, N- N-substituted maleimides such as (2-methoxyphenyl) maleimide, N- (2,4,6-trichlorophenyl) maleimide, N- (4-hydroxyphenyl) maleimide, N- (1-hydroxyphenyl) maleimide, and unsubstituted. Maleimide can be mentioned, and one or a combination of two or more of these can be used. Among these, N-phenylmaleimide, N- (2-methylphenyl) maleimide, and N- (2,6-diethylphenyl) have a large effect of improving heat resistance, good copolymerizability, and are easily available. Maleimide, N-lauryl maleimide, N-cyclohexylmaleimide, N-benzylmaleimide and the like are preferable, N-phenylmaleimide, N-cyclohexylmaleimide and N-benzylmaleimide are more preferable, and N-phenylmaleimide and N-benzylmaleimide are most preferable. ..
It is also preferable to use N-phenylmaleimide and N-benzylmaleimide in combination. The preferable ratio of N-phenylmaleimide and N-benzylmaleimide when used in combination is 99: 1 to 1:99 in terms of mass ratio.

The maleimide-based monomer (maleimide-based monomer unit) comprises all the monomer components (constituting the base polymer) constituting the polymer (base polymer) in (A) 100% by mass of the curable copolymer resin. It is preferably 10 to 60% by mass based on 100% by mass of all the monomer units.
The curable copolymer resin (A) preferably has 10 to 60% by mass of a constituent unit derived from the maleimide-based monomer represented by the formula (1) and an unsaturated carboxylic acid represented by the formula (2) in 100% by mass of the main chain. It may contain 10 to 40% by mass of a structural unit derived from an acid ester monomer, and may contain 10 to 40% by mass of a structural unit derived from an unsaturated carboxylic acid monomer, if necessary, and a radically polymerizable carbon-carbon in the side chain. It may have a double bond (ethylenically unsaturated group).
In the following, the description of the monomer unit indicates a structural unit derived from the monomer, and the polymerizable carbon-carbon double bond (C = C) in the monomer is a single bond (C-). It means the structural unit that became C). For example, the maleimide-based monomer unit means a structural unit derived from the maleimide-based monomer when the maleimide-based monomer is copolymerized or graft-polymerized.
The (A) curable copolymer resin of the present invention may be at least capable of thermosetting with the (D) thermosetting resin, but the components (A) have ethylenically unsaturated groups capable of photocuring with each other. Is preferable.

The curable copolymer resin (A) can be obtained by radically polymerizing an unsaturated carboxylic acid monomer or the like as necessary, using a maleimide-based monomer and an unsaturated carboxylic acid ester monomer as essential components. preferable.

The unsaturated carboxylic acid ester monomer will be described. Since the unsaturated carboxylic acid ester monomer has a thermosetting group such as a hydroxyl group, it reacts with the (D) thermosetting resin to improve the cured product properties. Examples of the unsaturated carboxylic acid ester monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate. , (Di) hydroxyalkyl (meth) acrylates such as 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2,3-dihydroxypropyl (meth) acrylate, and 2-hydroxymethyl ( Meta) acrylamide, 2-hydroxyethyl (meth) acrylamide, 2-hydroxypropyl (meth) acrylamide, 3-hydroxypropyl (meth) acrylamide, 4-hydroxybutyl (meth) acrylamide, hydroxypivalyl (meth) acrylamide, 5- Examples thereof include (meth) acrylicoyl-based monomers such as hydroxyalkyl (meth) acrylamide such as hydroxypentyl (meth) acrylamide and 6-hydroxyhexyl (meth) acrylamide, and one or more of these can be used. .. Of these, hydroxyalkyl (meth) acrylate is preferable, and 2-hydroxyethyl (meth) acrylate is particularly preferable from the viewpoint of copolymerizability.

Further, the unsaturated carboxylic acid ester monomer may be one in which the hydroxyl group (hydroxy group) of the above-exemplified monomer is changed to at least one of a carboxyl group, an amino group and a thiol group. That is, it may be carboxyalkyl (meth) acrylate, aminoalkyl (meth) acrylate, or thioalkyl (meth) acrylate.

Next, the unsaturated carboxylic acid (monomer) will be described. It is preferable to use an unsaturated carboxylic acid as a monomer in order to introduce a carboxyl group as an alkali-soluble group necessary for alkaline development and to improve the characteristics of the cured product. Specific examples include (meth) acrylic acid, crotonic acid, silicic acid, sorbic acid, fumaric acid, maleic acid and the like, and among them, (meth) acrylic acid is preferable because it has excellent properties of a cured product. Moreover, as another embodiment, another acid group may be introduced together with the carboxyl group or in place of the carboxyl group. Examples of other acid groups include functional groups that neutralize with alkaline water, such as phenolic hydroxyl groups, carboxylic acid anhydride groups, phosphoric acid groups, and sulfonic acid groups, and have only one of these groups. However, it may have two or more kinds. In the following description, the description for the carboxyl group also applies to the other acid groups described above.

Other copolymerizable monomer components may be used in obtaining the polymer (base polymer) as long as the properties are not adversely affected.
Specific examples of such monomer components include aromatic monomers; vinyl ester monomers such as vinyl acetate and vinyl adipate; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate and the like. (Meta) acrylic monomers; alkylvinyl ethers such as n-propylvinyl ether, isopropylvinyl ether, n-butylvinyl ether, isobutylvinyl ether, n-hexylvinyl ether, cyclohexylvinyl ether, 2-ethylhexylvinyl ether and the corresponding alkylvinyl (thio). Ether; an acid anhydride group-containing monomer such as maleic anhydride, a monomer obtained by ring-opening the acid anhydride group with alcohols, or an unsaturated basic acid other than those described above; N-vinylpyrrolidone, Examples thereof include N-vinyl-based monomers such as N-vinyloxazolidone; cyano group-containing monomers such as acrylonitrile and methacrylonitrile.

Among these, aromatic monomers are preferable because they have good copolymerizability with maleimide-based monomers and also have excellent properties of cured products. Specific examples include styrene, α-methylstyrene, α-chlorostyrene, vinyltoluene and the like, and styrene is most preferable because it has excellent electrical characteristics and is inexpensive.

(A) When introducing a polymerizable carbon-carbon double bond into a curable copolymer resin, for example, a functional group capable of reacting with the carboxyl group and ethylene with respect to the carboxyl group of the polymer (base polymer). A monomer having a sex unsaturated group is reacted to impart radical polymerizable property to obtain a radically polymerizable polymer.
The functional group capable of reacting with an acid group such as a carboxyl group is preferably selected from the group consisting of a glycidyl group, an oxazolinyl group, an isocyanate group and an oxetanyl group. The radically polymerizable carbon-carbon double bond is preferably a (meth) acryloyl group. As specific monomers, glycidyl (meth) acrylate and 3,4-epoxycyclohexylmethyl (meth) acrylate are preferable.

(A) When the curable copolymer resin has an ethylenically unsaturated group, the double bond equivalent is 600 to 4000 g / eq. It is preferable to carry out a radically polymerizable carbon-carbon double bond introduction reaction so as to be. The double bond equivalent is related to the photocurability and the physical properties of the cured product, and by setting the double bond equivalent within the above range, a cured product having excellent physical properties such as heat resistance, strength and flexibility can be provided. In addition, a well-balanced photosensitive resin having both photocurability and alkali developability can be obtained. A more preferred range of double bond equivalents is 700-3000 g / eq. More preferably, 800 to 2500 g / eq. Is.

When the curable copolymer resin (A) has a carboxyl group, its acid value is preferably 30 mgKOH / g or more, more preferably 40 mgKOH / g or more, further preferably 50 mgKOH / g or more, and preferably 160 mgKOH / g or less. , 155 mgKOH / g or less is more preferable, and 150 mgKOH / g or less is further preferable. When the acid value of the curable copolymer resin (A) is 30 mgKOH / g or more, good alkali developability can be easily exhibited. (A) When the acid value of the curable copolymer resin is 160 mgKOH / g or less, the exposed portion is less likely to be eroded by the alkaline developer, and the water resistance and moisture resistance of the cured product are improved.

The preferable range of the weight average molecular weight Mw of the curable copolymer resin (A) is determined by gel permeation chromatography (hereinafter, also referred to as “GPC”) in consideration of alkali developability, physical properties of the cured coating film, heat resistance and the like. The measured value is preferably 1,000 to 100,000 in terms of polystyrene.

The blending amount of the (A) curable copolymer resin is, for example, 10 to 80% by mass in the photosensitive resin layer excluding the (D) inorganic filler of the dry film.

(Alkali-soluble resin)
The photosensitive resin layer of the dry film of the present invention may further contain an alkali-soluble resin different from the component (A). The alkali-soluble resin may be any resin having an alkali-soluble group, and the alkali-soluble group is, for example, any one of a phenolic hydroxyl group, a thiol group and a carboxyl group. Examples of the alkali-soluble resin include compounds having two or more phenolic hydroxyl groups, carboxyl group-containing resins, compounds having phenolic hydroxyl groups and carboxyl groups, and compounds having two or more thiol groups, and among them, excellent developability. Therefore, a carboxyl group-containing resin is preferable. The carboxyl group-containing resin does not have to have an ethylenically unsaturated group, but a carboxyl group-containing photosensitive resin having an ethylenically unsaturated group is preferable from the viewpoint of photocurability and development resistance. .. As the ethylenically unsaturated group, a (meth) acryloyl group is preferable. As used herein, the term (meth) acryloyl group is a general term for acryloyl groups, methacryloyl groups, and mixtures thereof, and the same applies to other similar expressions. The alkali-soluble resin may be used alone or in combination of two or more.

Specific examples of the carboxyl group-containing resin include the following compounds (either oligomer or polymer).

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

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

(3) Diisocyanate and bifunctional epoxy resin such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, biphenol type epoxy resin ( Meta) A carboxyl group-containing photosensitive urethane resin obtained by a double addition reaction of an acrylate or a modified partial acid anhydride thereof, a carboxyl group-containing dialcohol compound and a diol compound.

(4) During the synthesis of the resin according to (2) or (3), a compound having one hydroxyl group and one or more (meth) acryloyl groups in a molecule such as hydroxyalkyl (meth) acrylate is added to the terminal (4). Meta) Acryloylated carboxyl group-containing photosensitive urethane resin.

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

(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 existing in a side chain.

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

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

(9) An epoxy compound having a plurality of epoxy groups in one molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule such as p-hydroxyphenethyl alcohol, and (meth). Reacting with an unsaturated group-containing monocarboxylic acid such as acrylic acid, maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipine with respect to the alcoholic hydroxyl group of the obtained reaction product. A carboxyl group-containing resin obtained by reacting a polybasic anhydride such as an acid.

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

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

(12) A carboxyl group-containing photosensitive resin obtained by further adding a compound having one epoxy group and one or more (meth) acryloyl groups in one molecule to the resins (1) to (11).

The alkali-soluble resin is preferably an alkali-soluble resin having an aromatic ring. As the alkali-soluble resin having an aromatic ring, a known and commonly used alkali-soluble resin may be used, and when synthesizing the alkali-soluble resin, a raw material having an aromatic ring may be used for synthesis. Examples of the alkali-soluble resin having an aromatic ring include the resin (10), the resin (11), and the corresponding resin (12). In addition, the resins (1) to (9) obtained by using a raw material having an aromatic ring and the corresponding resins (12) can also be mentioned.

The acid value of the alkali-soluble resin is preferably in the range of 40 to 200 mgKOH / g, more preferably in the range of 45 to 120 mgKOH / g. When the acid value of the alkali-soluble resin is 40 mgKOH / g or more, alkaline development becomes easy, while drawing a normal cured product pattern of 200 mgKOH / g or less becomes easy, which is preferable.

The weight average molecular weight of the alkali-soluble resin varies depending on the resin skeleton, but is preferably in the range of 1,500 to 150,000, more preferably 1,500 to 100,000. When the weight average molecular weight is 1,500 or more, the tack-free performance is good, the moisture resistance of the coating film after exposure is good, film loss during development can be suppressed, and deterioration of resolution can be suppressed. On the other hand, when the weight average molecular weight is 150,000 or less, the developability is good and the storage stability is also excellent.

The blending amount of the alkali-soluble resin is, for example, 0 to 70% by mass in the photosensitive resin layer excluding the (D) inorganic filler of the dry film.

[(B) Photopolymerization Initiator]
The photosensitive resin layer of the dry film of the present invention contains (B) a photopolymerization initiator. As the photopolymerization initiator (B), any photopolymerization initiator known as a photopolymerization initiator or a photoradical generator can be used. Light irradiation refers to irradiating active energy rays in the wavelength range of 350 to 450 nm.

Examples of the photopolymerization initiator include bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, and bis- (2, 6-Dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) 2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,4,6- Bisacylphosphine oxides such as trimethylbenzoyl) -phenylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphine Monoacylphosphine oxides such as acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide); 1-hydroxy-cyclohexyl Phenylketone, 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; benzoyl, benzyl, benzoyl Benzoyls such as methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether; benzoyl alkyl ethers; benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone , 4,4'-Bisdiethylaminobenzophenone and other benzophenones; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-diku Loroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) ) -Butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl) -1- [4- (4-morpholinyl) phenyl] -1-butanone, N, N-dimethylaminoacetophenone, etc. Acetphenones; thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone , 2-Methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone and other anthraquinones; acetphenone dimethyl ketal, benzyl dimethyl ketal and other ketals; ethyl Orthoperic acid esters such as -4-dimethylaminobenzoate, 2- (dimethylamino) ethylbenzoate, p-dimethylbenzoic acid ethyl ester; 1,2-octanedione, 1- [4- (phenylthio)-, 2-( O-benzoyloxime)], etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime) and other oxime esters; (Η5-2,4-cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-1-yl) phenyl) titanium, bis (cyclopentadienyl) -bis [2 6-Difluoro-3- (2- (1-pyr-1-yl) ethyl) phenyl] Titanocenes such as titanium; phenyldisulfide 2-nitrofluorene, butyroine, anisoine ethyl ether, azobisisobutyronitrile, tetra Methylthiolam disulfide and the like can be mentioned. As the photopolymerization initiator, one type may be used alone, or two or more types may be used in combination.

As the photopolymerization initiator (B), a photopolymerization initiator having a molar extinction coefficient at 365 nm of 5000 ml / g · cm or less is preferable, and more preferably 1000 ml / g · cm or less. However, this does not apply if the absorbance can be adjusted. The photopolymerization initiator of 5000 ml / g · cm or less is preferably acylphosphine oxides or aminoacetophenones. Specific examples of the photopolymerization initiator of 5000 ml / g · cm or less include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (2300 ml / g · cm) and 2,4,6-trimethylbenzoyl-diphenyl. -Phosphine oxide (472 ml / g · cm), 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one (470 ml / g · cm) and the like can be mentioned. The molar extinction coefficient of the photopolymerization initiator (B) is preferably 100 to 5000 ml / g · cm. When the molar extinction coefficient is 5000 ml / g · cm or less, it becomes easier to control the resolution of the thin film. When the molar extinction coefficient is 100 ml / g · cm or more, the photosensitivity is good and peeling during development can be suppressed. More preferably, it is 100 to 1000 ml / g · cm.

(B) The photopolymerization initiator may be used alone or in combination of two or more. The amount of the photopolymerization initiator (B) blended is, for example, 0.01 to 30% by mass in the photosensitive resin layer of the dry film.

[(C) Thermosetting resin]
The photosensitive resin layer of the dry film of the present invention contains a thermosetting resin. The thermosetting resin improves the heat resistance of the cured product and also improves the adhesion to the substrate. As the thermosetting resin, known and commonly used thermosetting resins such as isocyanate compounds, blocked isocyanate compounds, amino resins, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy compounds, polyfunctional oxetane compounds, and episulfide resins can be used. .. Among these, epoxy compounds, polyfunctional oxetane compounds, and compounds having two or more thioether groups in the molecule, that is, episulfide resins are preferable, and epoxy compounds are more preferable. The thermosetting resin may be used alone or in combination of two or more.

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

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

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

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

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

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

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

The blending amount of the (C) thermosetting resin is, for example, 1 to 50% by mass in the photosensitive resin layer excluding the (D) inorganic filler of the dry film.

[(D) Inorganic filler]
The photosensitive resin layer of the dry film of the present invention contains (D) an inorganic filler. The inorganic filler (D) is not particularly limited, and known and commonly used inorganic fillers such as amorphous silica, crystalline silica, fused silica, spherical silica and the like, Neuburg silica clay, aluminum hydroxide, glass powder, talc, etc. Clay, magnesium carbonate, calcium carbonate, natural mica, synthetic mica, aluminum hydroxide, barium sulfate, barium titanate, iron oxide, amorphous glass, hydrotalcite, mineral wool, aluminum silicate, calcium silicate, zinc flower, etc. Inorganic fillers can be used. (D) The inorganic filler preferably contains 5% by mass or more of silica. By blending 5% by mass or more of silica, more excellent thermal shock resistance can be obtained. Examples of silica include fused silica, spherical silica, amorphous silica, crystalline silica and the like, and spherical silica is preferable.

As described above, the photosensitive resin layer of the dry film of the present invention is excellent in resolvability despite containing an inorganic filler. % Or more, and even 30% by mass or more. The upper limit of the amount of silica blended is, for example, 80% by mass or less.

The inorganic filler (D) is preferably a surface-treated inorganic filler, and more preferably the surface of the inorganic filler is surface-treated so that a curable reactive group can be introduced. Here, the curable reactive group is not particularly limited as long as it is a group that cures with a curable compound such as an alkali-soluble resin or a thermosetting resin, and may be a photocurable reactive group or a thermosetting reactive group. Examples of the photocurable reactive group include a methacryl group, an acrylic group, a vinyl group, a styryl group and the like, and examples of the thermosetting reactive group include an epoxy group, an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, an imino group and an oxetanyl. Examples thereof include a group, a mercapto group, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, an oxazoline group and the like. The method for introducing the curable reactive group onto the surface of the inorganic filler is not particularly limited, and it may be introduced by using a known and commonly used method, and a surface treatment agent having a curable reactive group, for example, a curable reactive group is introduced as an organic group. The surface of the inorganic filler may be treated with a coupling agent or the like having the above. As the coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent and the like can be used. Examples of the surface-treated inorganic filler having no curable reactive group include silica-alumina surface treatment, titanate-based coupling agent treatment, aluminate-based coupling agent treatment, fluorene-based coupling agent treatment, and organic treatment. Examples thereof include inorganic fillers that have been removed. Further, as a surface treatment, the inorganic filler may be coated with a hydrated oxide of silicon, a hydrated oxide of aluminum, a hydrated oxide of zirconium, a hydrated oxide of zinc, a hydrated oxide of titanium, or the like. ..

The average particle size of the inorganic filler (D) is preferably 0.01 to 0.8 μm. Here, in the present specification, the average particle size of the inorganic filler is the average particle size (D50) including not only the particle size of the primary particles but also the particle size of the secondary particles (aggregates), and is a laser diffraction method. It is a value of D50 measured by. Examples of the measuring device by the laser diffraction method include the Microtrac MT3300EXII manufactured by Microtrac Bell.

The average particle size of the inorganic filler (D) may be adjusted, and it is preferable to pre-disperse the inorganic filler with, for example, a bead mill or a jet mill. Further, the inorganic filler is preferably blended in a slurry state, and by blending in a slurry state, high dispersion is facilitated, aggregation is prevented, and handling is facilitated.

(D) As the inorganic filler, one type can be used alone or two or more types can be used in combination. The blending amount of the inorganic filler (D) is preferably 5 to 80% by mass in the photosensitive resin layer, and is more tough than the resin alone.

(Compound with ethylenically unsaturated group)
The photosensitive resin layer of the dry film of the present invention may contain a compound having an ethylenically unsaturated group. As the compound having an ethylenically unsaturated group, known and commonly used photosensitive monomers such as a photopolymerizable oligomer and a photopolymerizable vinyl monomer can be used, and a radically polymerizable monomer or a cationically polymerizable monomer may be used.

As the photosensitive monomer, a liquid, solid or semi-solid photosensitive (meth) acrylate compound having one or more (meth) acryloyl groups in the molecule at room temperature can be used. The photosensitive (meth) acrylate compound, which is liquid at room temperature, has the purpose of increasing the photoreactivity of the composition, adjusting the composition to a viscosity suitable for various coating methods, and assisting in the solubility in an alkaline aqueous solution. Also fulfills.

The double bond equivalent of the photosensitive monomer is 400 g / eq. The following is preferable.

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

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

As the compound having an ethylenically unsaturated group, one kind may be used alone or two or more kinds may be used in combination. The blending amount of the compound having an ethylenically unsaturated group is preferably 0.1 to 30% by mass in the photosensitive resin layer of the dry film. When it is 30% by mass or less, the tack property is good and the influence of curing shrinkage is small. When it is 0.1% by mass or more, peeling is unlikely to occur during development.

(Curing accelerator)
The photosensitive resin layer of the dry film of the present invention can contain a curing accelerator. Examples of the curing accelerator include imidazole, 2-methylimidazole, 2-ethyl imidazole, 2-ethyl-4-methyl imidazole, 2-phenyl imidazole, 4-phenyl imidazole, 1-cyanoethyl-2-phenyl imidazole, 1-. Imidazole derivatives such as (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzyl Examples include amine compounds such as amines, 4-methyl-N, N-dimethylbenzylamine and 4-dimethylaminopyridine, hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. In addition, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine isocyanuric acid adduct can also be used. Of these, amine compounds are preferable because they improve dispersibility and fluidity. Further, preferably, a compound that also functions as an adhesion imparting agent is used in combination with a thermosetting catalyst. The curing accelerator may be used alone or in combination of two or more.

The amount of the curing accelerator blended is, for example, 0.01 to 30% by mass in the photosensitive resin layer of the dry film.

((E) Elastomer)
The photosensitive resin layer of the dry film of the present invention preferably contains (E) an elastomer. (E) Since the elastic modulus can be lowered by containing the elastomer, the stress at the time of curing can be relaxed to improve the connection reliability with a small amount of solder, the solvent crack can be suppressed, and the dry film can be used. Handleability can be improved. As the elastomer (E), known elastomers can be used, for example, polyester-based elastomers, styrene-based elastomers, polyurethane-based elastomers, polyester-urethane-based elastomers, polyamide-based elastomers, polyesteramide-based elastomers, acrylic-based elastomers, and olefin-based elastomers. Elastomers, silicone-based elastomers and the like can be used. Further, a resin obtained by modifying a part or all of the epoxy groups of an epoxy resin having various skeletons with both-terminal carboxylic acid-modified butadiene-acrylonitrile rubber can also be used. Further, epoxy-containing polybutadiene-based elastomers, acrylic-containing polybutadiene-based elastomers, hydroxyl group-containing polybutadiene-based elastomers, hydroxyl group-containing isoprene-based elastomers, block copolymers and the like can also be used. For example, the product names include R-45HT, Poly bd HTP-9 (manufactured by Idemitsu Kosan Co., Ltd.), Epolide PB3600 (manufactured by Daicel Chemical Co., Ltd.), Denarex R-45EPT (manufactured by Nagase ChemteX), and Tough Serene (Sumitomo Chemical Co., Ltd.). , Ricon series such as Ricon 130 (manufactured by Sartmer), Hytrel (manufactured by Toray DuPont), Perprene (manufactured by Toyobo), Esper 1612, 1620 (manufactured by Hitachi Chemical Co., Ltd.) and the like. These elastomers can be used alone or in combination of two or more.
The blending amount of the elastomer (E) is preferably 0.5 to 10% by mass in the photosensitive resin layer of the dry film.

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

The blending amount of the colorant is, for example, 0.01 to 10% by mass in the photosensitive resin layer of the dry film.

(UV absorber)
In the present invention, an ultraviolet absorber may be further contained in order to adjust the absorbance. Examples of the ultraviolet absorber include organic and / or inorganic ultraviolet absorbers.
Examples of the organic ultraviolet absorber include benzophenone derivatives, benzoate derivatives, benzotriazole derivatives, triazine derivatives, benzothiazole derivatives, synnamate derivatives, anthranilate derivatives, dibenzoylmethane derivatives and the like. Specific examples of the benzophenone derivative include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone and 2,4-dihydroxybenzophenone. Can be mentioned. Specific examples of benzoate derivatives include 2-ethylhexyl salicylate, phenyl salicylate, pt-butylphenyl salicylate, and 2,4-di-t-butylphenyl-3,5-di-t. Examples thereof include −butyl-4-hydroxybenzoate and hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate. Specific examples of the benzotriazole derivative include 2- (2'-hydroxy-5'-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2 -(2'-Hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3', 5'-di-t-butylphenyl) -5 -Chlorobenzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole and 2- (2'-hydroxy-3', 5'-di-t-amylphenyl) benzotriazole and the like can be mentioned. Specific examples of the triazine derivative include hydroxyphenyltriazine, bisethylhexyloxyphenol methoxyphenyl triazine and the like.
The UV absorber may be commercially available, for example, TINUVIN PS, TINUVIN 99-2, TINUVIN 109, TINUVIN 384-2, TINUVIN 900, TINUVIN 928, TINUVIN 1130, TINUVIN 400, TINUVIN 405, TINUVIN 460, Examples include TINUVIN 479 (above, manufactured by BASF Japan Ltd., product name).
In addition, examples of the inorganic ultraviolet absorber include carbon black and black titanium oxide (also referred to as titanium black), which can be used according to the application and required characteristics of the dry film of the present invention.

(Organic solvent)
The photosensitive resin layer of the dry film of the present invention may contain an organic solvent for the purpose of preparing a composition, adjusting the viscosity when applied to a substrate or a film, or the like. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethyl benzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol and propylene glycol monomethyl ether. , Dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, tripropylene glycol monomethyl ether and other glycol ethers; ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbi Esters such as tall acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, and solvent naphtha are known. Conventional organic solvents can be used. These organic solvents may be used alone or in combination of two or more.

(Other optional ingredients)
Further, the photosensitive resin layer of the dry film of the present invention may contain other additives known and commonly used in the field of electronic materials. Other additives include thermal polymerization inhibitors, silane coupling agents, plasticizers, flame retardants, antistatic agents, anti-aging agents, antioxidants, antibacterial / antifungal agents, antifoaming agents, leveling agents, thickening agents. Agent, Adhesion Improving Agent, Tixo Property Improving Agent, Photoinitiator Aid, Sensitizer, Organic Filler, Thermoplastic Resin, Release Agent, Surface Treatment Agent, Dispersant, Dispersion Aid, Surface Modifier, Stabilizer , A phosphor and the like.

The photosensitive resin layer of the dry film of the present invention may be an alkali-developed type or a solvent-developed type.

The photosensitive resin layer of the dry film of the present invention can be obtained by applying a photosensitive resin composition on the film and drying it. When forming a dry film, first, the photosensitive resin composition is diluted with the above organic solvent to adjust the viscosity to an appropriate level, and then a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, and a reverse coater. , Transfer coater, gravure coater, spray coater, etc., and apply to a uniform thickness on the film. Then, the applied composition is usually dried at a temperature of 40 to 130 ° C. for 1 to 30 minutes to form a photosensitive resin layer. The coating film thickness is not particularly limited, but the film thickness after drying is appropriately selected in the range of 3 to 13 μm, preferably 4 to 10 μm. In the present invention, either a carrier film or a cover film may be used as the film to which the photosensitive resin composition is applied when producing the dry film.

As the carrier film, a plastic film is used, and for example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film and the like can be used. The thickness of the carrier film is not particularly limited, but is generally selected as appropriate in the range of 10 to 150 μm. More preferably, it is in the range of 15 to 130 μm. The thickness of the carrier film may be larger or smaller than the thickness of the resin layer, but the larger the thickness of the resin layer, the better the handleability of the dry film.

After forming the photosensitive resin layer on the carrier film, a peelable cover film is further laminated on the surface of the photosensitive resin layer for the purpose of preventing dust from adhering to the surface of the photosensitive resin layer. Is preferable. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, surface-treated paper, or the like can be used. The cover film may be one that is smaller than the adhesive force between the photosensitive resin layer and the carrier film when the cover film is peeled off.

In the present invention, the photosensitive resin composition may be applied on the cover film and dried to form a photosensitive resin layer, and a carrier film may be laminated on the surface thereof.

If necessary, another resin layer may be provided between the film and the photosensitive resin layer. The photosensitive resin layer of the dry film of the present invention may be one layer or two or more layers.

As a method for producing a printed wiring board using the dry film of the present invention, a conventionally known method may be used. The case of a dry film having an alkali-developed photosensitive thermosetting resin layer will be described below.

A resin layer can be formed on the substrate by sticking the resin layer on the substrate with a laminator or the like so that the resin layer comes into contact with the substrate, and then peeling off the carrier film. The above-mentioned substrates include printed wiring boards and flexible printed wiring boards whose circuits are formed in advance with copper or the like, as well as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, and glass cloth / paper epoxy. Copper-clad laminates of all grades (FR-4, etc.) using materials such as copper-clad laminates for high-frequency circuits using synthetic fiber epoxy, fluororesin / polyethylene / polyimideene ether, polyphenylene oxide / cyanate, etc. In addition, metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates and the like can be mentioned. The circuit may be pretreated, for example, pretreated with GliCAP manufactured by Shikoku Chemicals Corporation, New Organic AP (Adhesion promoter) manufactured by MEC, Nova Bond manufactured by Atotech Japan, etc., and soldered. Adhesion to a cured film such as a resist may be improved, or pretreatment may be performed with a rust preventive.

After forming a resin layer on the printed wiring board, it is selectively exposed to active energy rays through a photomask having a predetermined pattern, and the unexposed portion is exposed to a dilute alkaline aqueous solution (for example, 0.3 to 3% by mass sodium carbonate aqueous solution). ) To form a pattern of the cured product. Further, the cured product is adhered by irradiating the cured product with active energy rays and then heat curing (for example, 100 to 220 ° C.), or by irradiating the cured product with active energy rays after heat curing or by performing final finish curing (main curing) only by heat curing. It forms a cured film with excellent properties such as properties and hardness.

As the exposure machine used for the above-mentioned active energy ray irradiation, if it is a device equipped with a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc., and irradiates the active energy ray in the range of 350 to 450 nm. Often, a projection exposure machine using a projection lens or a direct drawing device (for example, a laser direct imaging device that directly draws an image with a laser from CAD data from a computer) can also be used as a maskless exposure that does not contact the substrate. .. The lamp light source or the laser light source of the direct drawing machine may have a maximum wavelength in the range of 350 to 450 nm. The exposure amount for image formation varies depending on the film thickness and the like, but can be generally in the range of 10 to 1000 mJ / cm ² , preferably 20 to 800 mJ / cm ² .

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

The dry film of the present invention is suitably used for forming a cured film on an electronic component, particularly for forming a cured film on a sensor module or a printed wiring board, and more preferably for forming a permanent film. And more preferably used to form solder resists, interlayer insulating layers, coverlays. Further, it is suitable for forming a permanent coating (particularly solder resist) for a printed wiring board, for example, a package substrate, particularly FC-BGA, which requires a high degree of reliability. Further, since the dry film of the present invention is excellent in resolvability even if it is a thin film, it has an opening diameter of, for example, 3 to 13 μm, further 4 to 10 μm, and, for example, a diameter of 5 to 60 μm. It is suitable for forming a cured film. Further, it can be suitably used for manufacturing an electronic component having a small gap between a die and a substrate.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples. In the following, "part" and "%" are all based on mass unless otherwise specified. The numerical values shown in Table 1 are parts by mass of the solid content containing no solvent.

[Synthesis of alkali-soluble resin]
(Synthesis Example 1: Curable copolymer resin A-1 having a first repeating unit represented by the formula (1) and a second repeating unit represented by the formula (2))
81.5 parts of carbitol acetate was placed in a separable flask with a cooling tube as a reaction vessel, replaced with nitrogen, and then the temperature was raised to 80 ° C. On the other hand, 30 parts of N-phenylmaleimide and 120 parts of carbitol acetate were mixed in the dropping tank 1, 29 parts of styrene and 20 parts of 2-hydroxyethyl methacrylate were mixed in the dropping tank 2, and the dropping tank 3 21 parts of acrylic acid and 10.6 parts of hydrocarbon acetate are mixed, and the dropping tank 4 contains 70% of t-butylperoxypivalate as a polymerization initiator, Luperox 11 (trade name: manufactured by Alchema Yoshitomi Co., Ltd.). A mixture of 10 parts (hydrocarbon solution) and 21.2 parts of carbitol acetate was charged. While maintaining the reaction temperature at 80 ° C., the dropping was carried out from the dropping tanks 1, 2, 4 to 3 hours and from the dropping tank 3 for 2.5 hours. After the completion of the dropping, the reaction was continued at 80 ° C. for 30 minutes. Then, the reaction temperature was raised to 95 ° C., and the reaction was continued for 1.5 hours to obtain a polymer solution before the radical polymerizable double bond introduction reaction.
Next, 9.9 parts of glycidyl methacrylate, 7.4 parts of carbitol acetate as a reaction catalyst, 0.7 parts of triphenylphosphine as a reaction catalyst, and Antage W-400 (manufactured by Kawaguchi Chemical Industry Co., Ltd.) as a polymerization inhibitor in this polymer solution. ) Was added, and a mixed gas of nitrogen and oxygen (oxygen concentration 7%) was reacted at 115 ° C. while bubbling to obtain a solution of the radically polymerizable polymer A-1. This photosensitive carboxyl group-containing copolymer resin had a solid content of 32% and a solid content acid value of 120 mgKOH / g.

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

(Synthesis Example 3: Alkali Soluble Resin R-2)
700 g of diethylene glycol monoethyl ether acetate and 1070 g of orthocresol novolac type epoxy resin (manufactured by DIC, EPICLON N-695, softening point 95 ° C., epoxy equivalent 214, average number of functional groups 7.6) (number of glycidyl groups (total number of aromatic rings) ): 5.0 mol), 360 g (5.0 mol) of acrylic acid, and 1.5 g of hydroquinone were charged, heated and stirred at 100 ° C., and uniformly dissolved.
Next, 4.3 g of triphenylphosphine was charged, heated to 110 ° C. for 2 hours, then 1.6 g of triphenylphosphine was further added, the temperature was raised to 120 ° C., and the reaction was further carried out for 12 hours. To the obtained reaction solution, 562 g of aromatic hydrocarbon (Solbesso 150) and 684 g (4.5 mol) of tetrahydrophthalic anhydride were charged, and the reaction was carried out at 110 ° C. for 4 hours. Further, 142.0 g (1.0 mol) of glycidyl methacrylate was charged into the obtained reaction solution, and the reaction was carried out at 115 ° C. for 4 hours to obtain a photosensitive carboxyl group-containing resin solution. The solid content of the resin solution thus obtained was 65%, and the acid value of the solid content was 87 mgKOH / g. Hereinafter, this carboxyl group-containing photosensitive resin is referred to as R-2.

(Synthesis Example 4: Alkali Soluble Resin R-3)
In a flask equipped with a thermometer, a stirrer, a dropping funnel, and a reflux cooler, 325.0 parts of dipropylene glycol monomethyl ether as a solvent was heated to 110 ° C., 174.0 parts of methacrylic acid, ε-caprolactone-modified methacrylic acid. (Average molecular weight 314) 174.0 parts, 77.0 parts of methyl methacrylate, 222.0 parts of dipropylene glycol monomethyl ether, and t-butylperoxy2-ethylhexanoate as a polymerization catalyst (Perbutyl O manufactured by Nippon Oil & Fats Co., Ltd.) ) 12.0 parts of the mixture was added dropwise over 3 hours, and the mixture was further stirred at 110 ° C. for 3 hours to inactivate the polymerization catalyst to obtain a resin solution.
After cooling this resin solution, 289.0 parts of Cyclomer A200 manufactured by Daicel Chemical Industry Co., Ltd., 3.0 parts of triphenylphosphine and 1.3 parts of hydroquinone monomethyl ether are added, the temperature is raised to 100 ° C., and the mixture is stirred. A ring-opening addition reaction of an epoxy group was carried out to obtain a photosensitive solution of a carboxyl group-containing resin R-3.
The solid content of the solution of the resin R-3 thus obtained was 57%, and the acid value of the solid content was 79.8 mgKOH / g.

[Preparation of filler]
(Preparation Example 1: Silica D-1 surface-treated with a silane coupling agent having a methacryl group)
Uniformly contains 60 g of spherical silica (SFP-20M manufactured by Denka Co., Ltd., average particle size: 400 nm), 38 g of MEK (methyl ethyl ketone) as a solvent, and 2 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.). The mixture was dispersed to obtain a solvent-dispersed product D-1 of silica surface-treated with a silane coupling agent having a methacryl group.

(Preparation Example 2: Silica D-2 surface-treated with a silane coupling agent having an amino group)
Uniformly contains 60 g of spherical silica (SFP-20M manufactured by Denka, average particle size: 400 nm), 38 g of MEK (methyl ethyl ketone) as a solvent, and 2 g of a silane coupling agent having an amino group (KBM-603 manufactured by Shin-Etsu Chemical Co., Ltd.). The mixture was dispersed to obtain a solvent-dispersed product D-2 of silica surface-treated with a silane coupling agent having an amino group.

(Preparation Example 3: Silica D-3 surface-treated with a silane coupling agent having fluorene)
Uniform dispersion of 60 g of spherical silica (SFP-20M manufactured by Denka, average particle size: 400 nm), 38 g of MEK (methyl ethyl ketone) as a solvent, and 2 g of a silane coupling agent having fluorene (SC-001 manufactured by Osaka Gas Chemical Co., Ltd.). Then, a solvent-dispersed product D-3 of silica surface-treated with a silane coupling agent having a fluorene group was obtained.

(Preparation Example 4: Alumina D-4 surface-treated with a silane coupling agent having a methacrylic group)
60 g of spherical alumina (AO-502 manufactured by Admatex, average particle size: 250 nm), 40 g of MEK (methyl ethyl ketone) as a solvent, and 3 g of a silane coupling agent having a methacryl group (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.). Uniformly dispersed to obtain a solvent-dispersed product D-4 of alumina surface-treated with a silane coupling agent having a methacrylic group.

(Preparation Example 5)
80 g of barium sulfate (Sakai Chemical Industry Co., Ltd. B-30, average particle size: 300 nm) surface-treated with silica-alumina and 20 g of MEK (methyl ethyl ketone) as a solvent are uniformly dispersed, and the solvent-dispersed product of barium sulfate D- I got 5.

[Examples 1 to 8, Comparative Examples 1 to 4]
The above resin solution (varnish) and various components shown in Table 1 are mixed at the ratio (parts by mass) shown in Table 1, premixed with a stirrer, and then kneaded with a three-roll mill to make a photosensitive resin. The composition was prepared.

<Making dry film>
300 g of methyl ethyl ketone was added to the photosensitive resin composition obtained as described above to dilute it, and the mixture was stirred with a stirrer for 15 minutes to obtain a coating liquid. The coating liquid was applied onto a polyethylene terephthalate film having a thickness of 38 μm (carrier film: Embret PTH-25 manufactured by Unitika Ltd.) and dried at a temperature of 80 ° C. for 15 minutes to form a resin layer having a thickness of 10 μm. .. Next, a biaxially stretched polypropylene film (cover film: OPP-FOA manufactured by Futamura Co., Ltd.) was laminated on the resin layer to prepare a dry film.

<Measurement method of double bond equivalent>
The photosensitive resin composition was dried at 70 ° C. for 24 hours to remove the organic solvent to obtain a solid content. Acetone was added to the solid content to dissolve and disperse it, and an organic component obtained by separating the inorganic filler from the solid content was obtained from a centrifuge. After reacting this organic component with morpholine, acetic anhydride was added to react with unreacted morpholine. The double bond equivalent of the organic component was calculated by titrating the reaction product of the organic component and morpholine with perchloric acid. Then, it was converted into a double bond equivalent containing an inorganic filler.

<Amount of residual solvent in the photosensitive resin layer>
A photosensitive resin layer of a dry film at 70 ° C. for 60 seconds was laminated on a copper foil (1) having a thickness of 35 μm using CVP-300 manufactured by Nikko Material Co., Ltd. Next, the support film was peeled off (2) and dried at 100 ° C. for 30 minutes to completely remove the solvent (3).
The residual solvent of the photosensitive resin layer was calculated based on the following formula for calculating the residual solvent.
(Calculation formula for residual solvent)
Percentage of residual solvent (%) = (mass of (2)-mass of (3)) / (mass of (2)-mass of (1)) x 100
Weight of (1): Weight of copper foil (2) Weight: Weight of copper foil and photosensitive resin layer of dry film combined Weight of (3): Weight of copper foil and photosensitive resin layer after drying combined Weight

<Absorptivity of photosensitive resin layer with light wavelength of 365 nm>
The dry films of Examples and Comparative Examples having a resin layer having a thickness of 10 μm were laminated on glass, the PET film was peeled off, and then this glass substrate was set on an ultraviolet-visible spectrophotometer and an absorption spectrum of 365 nm was measured. The absorbance at 365 nm was measured.

<Resolution>
Vacuum pressure of 3 hPa, vacuum in the first chamber at 100 ° C. using a vacuum laminator (CVP-600: manufactured by Nikko Material Co., Ltd.) on the copper of the copper-clad laminate in which the dry films of each example and the comparative example were acid-treated. After laminating under the condition of a time of 30 seconds, pressing was performed under the conditions of a press pressure of 0.5 MPa and a press time of 30 seconds to obtain an evaluation substrate. Then, after exposing the SRO pattern of φ30 μm with an exposure amount of 10 steps with a step tablet (41 steps) with a DI exposure machine, the PET film was peeled off and developed (1 mass% Na ₂ CO ₃ , 30 ° C., 0. 2 MPa) was carried out in 60 seconds to form a pattern of the resin layer. Subsequently, the resin layer is irradiated with an exposure amount of 1 J / cm ^{2 in} a UV conveyor furnace equipped with a high-pressure mercury lamp, and then heated at 160 ° C. for 60 minutes to completely cure the resin layer to have an evaluation substrate having a pattern cured film. Was prepared, and the length of the photosensitive cured coating film was measured.
⊚: Top 30 μm, Bottom opening 95-100%
〇: Top 30 μm, Bottom opening 85% or more and less than 95% Δ: Both Top and Bottom have an opening accuracy of 80 to 90% ×: Halation and undercut occur

<Solvent crack resistance>
Similar to the above <resolution> evaluation, acetone is dropped after laminating, exposing, developing, and curing on a 4-inch, 150 μm-thick P-type silicon wafer having a 100 nm SiO ₂ film formed on one side manufactured by Canosis. After leaving it for 5 minutes, the state of the surface of the cured film from which the solvent had been removed was visually confirmed.
◎: No solvent crack.
Δ: No solvent crack was generated, but the surface was discolored whitish.
X: Solvent crack occurred.

<Cold heat shock resistance>
Similar to the above <Resolution> evaluation, after laminating, exposing, developing, and curing on a 4-inch, 150 μm-thick P-type silicon wafer with a 100 nm SiO ₂ film formed on one side, solder heat resistance ( A reliability test was conducted with 250 ° C. (3 times for 10 seconds) and 500 thermal cycles (1 cycle is to leave at −40 ° C. for 15 minutes and then at 125 ° C. for 15 minutes). After that, the pseudo wafer was observed under a microscope to confirm whether cracks or peeling had occurred.
⊚: No peeling or cracking.
X: Peeling or cracking occurred.

<Insulation reliability>
Acid treatment on a printed wiring board on which a fine circuit of a comb tooth pattern with a surface roughness Ra of 0.04 μm, a copper thickness of 8 μm, and L (line: wiring width) / S (space: spacing width) = 8/8 μm is formed. And dried. After peeling off the protective film from the dry films of each example and comparative example on the printed wiring board, vacuum pressure is applied in the first chamber at 90 ° C. using a vacuum laminator (CVP-300: manufactured by Nikko Material Co., Ltd.). Lamination was performed under the conditions of 3 hPa and a vacuum time of 30 seconds, and pressing was performed under the conditions of a press pressure of 0.5 MPa and a press time of 30 seconds to obtain an evaluation substrate. An exposure device equipped with a high-pressure mercury lamp (short arclamp) was used to expose the dry film (exposure amount: 400 to 600 mJ / cm ² ), and then the polyethylene terephthalate film was peeled off from the dry film to expose the resin layer. .. Then, using a 1 wt% Na ₂ CO ₃ aqueous solution, development was carried out under the conditions of 30 ° C. and a spray pressure of 2 kg / cm ² for 60 seconds to form a pattern of the resin layer. Subsequently, the resin layer is irradiated with an exposure amount of 1 J / cm ^{2 in} a UV conveyor furnace equipped with a high-pressure mercury lamp, and then heated at 160 ° C. for 60 minutes to completely cure the resin layer to have an evaluation substrate having a pattern cured film. Was produced. When the electrodes were connected to this evaluation board, placed in a constant temperature and humidity chamber in an atmosphere of 130 ° C. and 85% humidity, and the HAST test was performed under the condition of a voltage of 3 V, the electrical insulation became 1 × 10 ⁶ Ω or less. The time was measured.
⊚: 500 hours or more 〇: 350 hours or more and less than 500 hours Δ: 200 hours or more and less than 350 hours ×: less than 200 hours

<Handling>
The B-stage state (semi-cured state) of the photosensitive resin layer of the dry films of each example and comparative example was evaluated. Slit processing was performed on the dry film on which the photosensitive resin layer was formed to a predetermined size, and the state of the dry film was confirmed by the following method.
(Evaluation method)
⊚: After slitting, no cracking of the resin layer or falling of resin powder was confirmed.
Δ: Slight cracking of the resin layer was confirmed after slitting. No resin powder was found to fall off.
X: After slitting, cracking of the resin layer and falling of resin powder were confirmed.

* 1: Alkali-soluble resin A-1 synthesized above (carboxyl group equivalent 451.69 g / eq.)
* 2: Alkali-soluble resin R-1 synthesized above (carboxyl group equivalent 654.43 g / eq.)
* 3: Alkali-soluble resin R-2 synthesized above (carboxyl group equivalent 656 g / eq.)
* 4: Alkali-soluble resin R-3 synthesized above (carboxyl group equivalent 370 g / eq.)
* 5: Omnirad 907 manufactured by IGM Resins (2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, molar extinction coefficient 470 ml / g · cm with a light wavelength of 365 nm)
* 6: Omnirad TPO manufactured by IGM Resins (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, molar extinction coefficient 472 ml / g · cm with a light wavelength of 365 nm)
* 7: OXE-02 (Etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (0-acetyloxime)) manufactured by BASF Japan Ltd., Hikari Molar extinction coefficient of 365 nm wavelength 7700 ml / g · cm)
* 8: DPHA (dipentaerythritol hexaacrylate) manufactured by Nippon Kayaku Co., Ltd.
* 9: Mitsubishi Chemical Corporation jER828 (bisphenol A type epoxy resin, epoxy equivalent 189 g / eq.)
* 10: Nippon Kayaku Co., Ltd. NC-6000 (2- (4-hydroxyphenyl) -2- [4- [1,1-bis (4-hydroxyphenyl) ethyl] phenyl] propane glycidyl ether compound, epoxy equivalent 210 g / eq.)
* 11: NC-3000H manufactured by Nippon Kayaku Co., Ltd. (biphenol novolac type epoxy resin, epoxy equivalent 290 g / eq.)
* 12: Phthalocyanine blue * 13: DICY (dicyandiamide)
* 14: Melamine * 15: Solvent dispersion product D-1 of silica surface-treated with the silane coupling agent having a methacrylic group prepared above (the amount in the table is the amount of solid content).
* 16: Solvent-dispersed product D-2 of silica surface-treated with the silane coupling agent having an amino group prepared above (the amount in the table is the amount of solid content).
* 17: Solvent-dispersed product D-3 of silica surface-treated with the silane coupling agent containing fluorene prepared above (the amount in the table is the amount of solid content).
* 18: Solvent-dispersed product D-4 of alumina surface-treated with the silane coupling agent having a methacrylic acid group prepared above (the amount in the table is the amount of solid content).
* 19: Solvent-dispersed product D-5 of barium sulfate surface-treated with silica-alumina prepared above (the amount in the table is the amount of solid content)
* 20: Epolide PB3600 (epoxydated polybutadiene) manufactured by Daicel Corporation.
* 21: Amount of residual solvent in the photosensitive resin layer * 22: Double bond equivalent of the component excluding the organic solvent from the photosensitive resin layer

From the results shown in the above table, the dry films of Examples 1 to 8 of the present invention have a resin layer obtained from a photosensitive resin composition having excellent resolution, handleability, and thermal shock resistance of a cured product. It turns out to have.

Claims (8)

A dry film comprising a film and a photosensitive resin layer provided on one surface of the film and having a thickness of 3 to 13 μm and an absorbance of 0.5 to 1.5 at a light wavelength of 365 nm.
The photosensitive resin layer is
(A) A curable copolymer resin having at least a first repeating unit represented by the following formula (1) and a second repeating unit represented by the following formula (2).
(B) Photopolymerization initiator,
A dry film characterized by containing (C) a thermosetting resin and (D) an inorganic filler.

(In the formula, R ₀ is a monovalent organic group having 1 to 30 carbon atoms, R ₁ is a hydrogen atom or an organic group having 1 to 7 carbon atoms, and R ₂ is a single bond or 1 carbon number. It is an alkylene group of ~ 5, and R ₃ represents a monovalent group having thermocrosslinkability.) The double bond equivalent of the component obtained by removing the organic solvent from the photosensitive resin layer is 500 to 1,000 g / eq. The dry film according to claim 1, wherein the dry film is characterized by the above. The dry film according to claim 1 or 2, wherein the content of the inorganic filler (D) is 5 to 80% by mass in the photosensitive resin layer. The dry film according to any one of claims 1 to 3, wherein the inorganic filler (D) is surface-treated. The dry film according to any one of claims 1 to 4, wherein the photosensitive resin layer further contains (E) an elastomer. The dry film according to any one of claims 1 to 5, wherein the amount of residual solvent in the photosensitive resin layer is 0.4 to 1.5% by mass. A cured product obtained by curing the photosensitive resin layer of the dry film according to claims 1 to 6. An electronic component having the cured product according to claim 7.