WO2023145974A1 - Film laminate, cured product, and printed wiring board comprising said cured product - Google Patents

Abstract

[Problem] To provide a film laminate comprising a film and a resin composition layer provided on one surface of said film, wherein when a resin composition is applied to the film and dried, the repellency of the resin composition on the film is suppressed. [Solution] A film laminate comprises: a first film; and a resin composition layer provided on one surface of the first film, wherein 15°≤A≤30° and 0.75A≤B≤1.3A are satisfied, where A is a contact angle between the first film and the resin composition at 25 °C, and B is a contact angle between the first film and the resin composition at 75 °C.

Description

Film laminate, cured product, and printed wiring board comprising the cured product

The present invention relates to a film laminate, and more particularly to a film laminate suitable for forming a solder resist. Furthermore, the present invention also relates to a cured product of the film laminate and a printed wiring board comprising the cured product.

With the increasing precision and density of printed wiring boards due to the recent miniaturization of electronic devices, the solder resist layer is formed by applying a photosensitive resin composition to the substrate, drying it, and curing it to form a pattern. It is mainly formed by so-called photosolder resist ink, in which the formed resin is fully cured by heating or light irradiation.

Also, a dry film obtained by applying a photosensitive resin composition to a support film is used to form a solder resist layer without using a liquid photosensitive resin composition. Compared to the case of using a liquid photosensitive resin composition as described above, the dry film not only can omit the drying process, but also can be exposed while the layer of the photosensitive resin composition is covered with the support film. There is an advantage that the effect inhibition by oxygen is small, and the resulting solder resist layer has high surface smoothness and surface hardness (for example, Patent Document 1, etc.).

On the other hand, since a dry film is obtained by applying a photosensitive resin composition to a support film, there is a problem that the resulting dry film suffers from defects due to repelling of the photosensitive resin composition by the support film during application. be. Specifically, the support film repels the applied photosensitive resin composition, so that the thickness of the layer of the photosensitive resin composition on the support film becomes uneven, and the surface of the layer of the photosensitive resin composition may not be sufficiently smooth. Moreover, a solder resist layer obtained from such a dry film has a problem that it cannot sufficiently exhibit the properties such as insulation properties required for the solder resist.

JP-A-7-15119

Therefore, an object of the present invention is to provide a film laminate in which repelling of the resin composition on the first film is suppressed when the resin composition is applied to the first film and dried. Another object of the present invention is to provide a cured product obtained by curing the resin composition layer of the film laminate, and a printed wiring board comprising the cured product.

In the film laminate as described above, the present inventors have found that the contact angles between the first film and the resin composition at 25 ° C. and 75 ° C. respectively satisfy specific ranges, so that the resin on the first film It was found that repelling of the resin composition on the first film during coating and drying of the composition can be suppressed. The present invention is based on such findings. That is, the gist of the present invention is as follows.

[1] A film laminate comprising a first film and a resin composition layer provided on one surface of the first film,
When the contact angle between the first film and the resin composition at 25°C is A, and the contact angle between the first film and the resin composition at 75°C is B,
15°≦A≦30°, and 0.75A≦B≦1.3A,
A film laminate that satisfies
[2] The film laminate according to [1], wherein the resin composition has a viscosity of 1.0 to 10 dPa·s at 5 rpm at 25°C.
[3] The film laminate according to [1] or [2], wherein the surface of the first film in contact with the resin composition layer has an arithmetic mean roughness of less than 0.2 µm.
[4] The film laminate according to any one of [1] to [3], wherein the maximum height of the surface of the first film in contact with the resin composition layer is less than 4.0 μm.
[5] The film laminate according to any one of [1] to [4], wherein the resin composition constituting the resin composition is a photosensitive resin composition.
[6] The film laminate according to any one of [1] to [5], wherein the surface of the first film in contact with the resin composition layer is surface-treated.
[7] The film laminate according to any one of [1] to [6], which is a dry film.
[8] The film laminate according to any one of [1] to [7], which is used for forming a solder resist layer.
[9] The film laminate according to [8], wherein the solder resist layer is a matte solder resist layer.
[10] A cured product obtained by curing the resin composition layer of the film laminate according to any one of [1] to [9].
[11] A printed wiring board comprising the cured product according to [10].

According to the present invention, in a film laminate comprising a first film and a resin composition layer provided on one surface of the first film, the first film and the resin composition are When the contact angles A and B at 75° C. each satisfy a specific range, repelling of the resin composition on the first film during coating and drying of the resin composition on the first film was suppressed. Film laminates can be realized. Furthermore, according to the present invention, since the repelling of the resin composition on the film constituting the film laminate is suppressed, unevenness in the color and thickness of the resin composition layer in the film laminate, that is, color unevenness It is also possible to suppress variations in film thickness.

[Film laminate]
A film laminate of the present invention comprises a first film and a resin composition layer provided on one surface of the first film. In one embodiment of the present invention, the film laminate may comprise layers other than the first film and the resin composition layer. For example, a second film may be provided on the surface of the resin composition layer. The film laminate of the invention is preferably used as a dry film. In addition, the film laminate of the present invention can be suitably used particularly for forming a solder resist layer, preferably a matte solder resist layer, of a printed wiring board.

In the film laminate of the present invention, the contact angle A between the first film and the resin composition at 25° C. satisfies the range of 15°≦A≦30°, preferably 18°≦A≦25°. Be satisfied. Since the contact angle between the first film and the resin composition at 25°C is 30° or less, at a general temperature (for example, room temperature) at which the resin composition is applied to the film in the production of the film laminate, Repelling can be suppressed when the resin composition is applied onto the first film. On the other hand, when the contact angle between the first film and the resin composition at 25° C. is 15° or more, it is possible to suppress excessive wetting and spreading upon application.

Further, in the film laminate of the present invention, the contact angle B between the first film and the resin composition at 75 ° C. is the above-mentioned contact angle A between the first film and the resin composition at 25 ° C. , 0.75A≤B≤1.3A, preferably 0.9A≤B≤1.2A. The contact angles A and B between the first film and the resin composition at 25 ° C. and 75 ° C. satisfy the above ranges, so that the resin composition is applied to the film and then dried at a general temperature (e.g., 75 ° C.), the repelling of the resin composition on the first film can be suppressed. The method for adjusting the contact angles A and B between the first film and the resin composition at 25° C. and 75° C. is not particularly limited, and can be appropriately adjusted by a conventionally known method. As a method for adjusting each contact angle, for example, in the film laminate of the present invention, a method of appropriately adjusting the material of the first film described later, and an arithmetic mean roughness and maximum height of the first film described later are appropriately adjusted. a method of appropriately adjusting the viscosity of the resin composition described later, a method of appropriately adjusting the solvent in the resin composition described later, and the like. Each of these methods may be performed singly or in combination of two or more.

As described above, the film laminate of the present invention has a sufficiently small contact angle A between the first film and the resin composition at 25 ° C., and a contact angle A between the first film and the resin composition at 75 ° C. Since B does not change greatly compared to the contact angle A, repelling when the resin composition is applied on the first film can be suppressed, and repelling when drying the applied resin composition can also be suppressed. As a result, non-uniformity in the thickness of the resin composition layer on the film caused by the film repelling the resin composition can be suppressed, and a resin composition layer having sufficiently high surface smoothness can be formed. In the film laminate, the thickness uniformity (surface smoothness) of the resin composition layer is considered to have a great effect on the performance of the solder resist layer obtained by curing it. Therefore, by suppressing the first film from repelling the resin composition in the production of the film laminate, the uniformity of the thickness of the resin composition layer (surface smoothness) is improved, and in turn the production of the film laminate It is considered that the yield in the process can be improved. Each element constituting the film laminate of the present invention will be described in detail below.

<First film>
A film laminate of the present invention comprises a first film. The first film preferably serves as a support for the resin composition layer to be described later, and the resin composition layer provided on one side of the first film is formed on a substrate such as a substrate. In the case of integral molding by lamination by heating or the like so as to be in contact with each other, it is at least adhered to the resin composition layer. The first film may be peeled off from the resin composition layer in a step after lamination of the substrate and the resin composition layer. Particularly in the present invention, the first film is preferably peeled off from the resin composition layer in a step after curing the resin composition layer.

As the first film, any known film can be used without any particular limitation. A film made of a plastic resin can be preferably used. Among these, polyester films are preferred, and polyethylene terephthalate films are particularly preferred, from the viewpoint of heat resistance, mechanical strength, handleability, and the like. A laminate of these films can also be used as the first film.

In addition, from the viewpoint of improving the mechanical strength, the film made of the thermoplastic resin as described above is preferably a film stretched uniaxially or biaxially.

In the present invention, as the first film, as described above, a film is used in which the contact angles A and B between the first film and the resin composition at 25°C and 75°C respectively satisfy the ranges described above. The means for adjusting the contact angle at each temperature is not particularly limited, and the material constituting the first film may be changed in relation to the resin composition, or the resin composition layer of the first film may be changed. The contact angle with the resin composition can be adjusted by subjecting the surface in contact with the surface to surface treatment. Examples of the surface treatment applied to the surface of the first film include matte treatment and corona treatment. The matte treatment includes, for example, coating type, kneading type, and the like.

In the present invention, the contact angle between the first film and the resin composition at each temperature is measured in accordance with JIS R3257: 1999, using a contact angle meter DropMaster DMo-601 (manufactured by Kyowa Interface Science Co., Ltd.) and multifunctional integrated analysis software. Using FAMAS (manufactured by Kyowa Interface Science Co., Ltd.), a droplet formed by dropping 0.25 μL of the resin composition onto the film using a syringe with a needle is photographed from the horizontal side and obtained. can be measured by analyzing the contact angle of the droplet at the film interface of the captured image. The contact angle of the droplet at the film interface is the angle formed by the tangent to the droplet surface and the film surface at the point where the film and the droplet contact, and is the angle on the side containing the droplet. In one embodiment, the above-described droplet image capturing and contact angle analysis are performed on a plurality of droplets, preferably 2 or more, more preferably 3 or more, and even more preferably 5 or more droplets. is done about

The arithmetic mean roughness (Ra) of the surface of the first film in contact with the resin composition layer is not particularly limited as long as the effects of the present invention are exhibited, but is preferably less than 0.2 μm. When the arithmetic mean roughness of the surface of the first film in contact with the resin composition layer is within the range described above, uniform coating can be achieved. In the present invention, the arithmetic mean roughness of the surface in contact with the resin composition layer of the first film is measured using a laser microscope VK-X series (manufactured by Keyence Corporation) corresponding to the non-contact measurement method, JISB0601: 2001 ( ISO4287:1997) can be measured. Specifically, the target portion can be measured by setting the magnification of the surface of the first film in the range of 50 μm×100 μm to 50 times. In one embodiment, the measurement of the arithmetic mean roughness of the first film described above is performed at a plurality of randomly selected locations of the first film, preferably 2 or more, more preferably 5 or more, and even more preferably is performed at 10 or more locations. When measured at multiple points, the arithmetic mean roughness of the first film is the average value of the measured values at those multiple points.

The maximum height (Rz) of the surface of the first film in contact with the resin composition layer is not particularly limited as long as the effects of the present invention are exhibited, but is preferably less than 4.0 µm. When the maximum height of the surface of the first film in contact with the resin composition layer is within the range described above, it is possible to suppress occurrence of uncoated portions (missing areas). The maximum height of the surface of the first film in contact with the resin composition layer is measured using a laser microscope VK-X series (manufactured by Keyence Corporation) corresponding to the non-contact measurement method, JIS B0601: 2001 (ISO4287: 1997). can be measured according to Specifically, the target portion can be measured by setting the magnification of the surface of the first film in the range of 50 μm×100 μm to 50 times. In one embodiment, the measurement of the arithmetic mean roughness of the first film described above is performed at a plurality of randomly selected locations of the first film, preferably 2 or more, more preferably 5 or more, and even more preferably is performed at 10 or more locations. When measured at multiple points, the arithmetic mean roughness of the first film is the average value of the measured values at those multiple points.

The thickness of the first film is not particularly limited, but considering flexibility and bendability, it is usually about 1 to 1000 μm, preferably 5 to 500 μm, more preferably 10 to 200 μm, especially It is preferably 20 to 200 μm.

<Resin composition layer>
The film laminate of the present invention comprises a resin composition layer provided on one surface of the first film. The resin composition layer preferably forms a cured layer through a curing step, and particularly preferably forms a solder resist layer. Therefore, the resin composition forming the resin composition layer preferably contains a photosensitive resin.

The viscosity of the resin composition constituting the resin composition layer is not particularly limited, but the viscosity at 5 rpm at 25° C. is preferably 1.0 to 10 dPa·s, more preferably 1.0 to 5.0 dPa·s. is s. When the viscosity of the resin composition is within the above range, the film thickness of the resin composition (thickness of the resin composition layer) can be uniformly adjusted when the resin composition is applied to a film. In the present invention, the viscosity of the resin composition is measured by collecting 1.0 ml of the resin composition and using a cone-plate viscometer TV-33H (rotor 1°34′×R24, manufactured by Toki Sangyo Co., Ltd.). is the value of the viscosity measured after rotating for 30 seconds at 5 rpm (shear rate 10-1 s) at 25°C.

(Photosensitive resin)
The photosensitive resin contained in the resin composition layer is not particularly limited, but a carboxyl group-containing resin is preferably used from the viewpoint of imparting alkali developability to the resin composition layer. As the carboxyl group-containing resin, conventionally known various resins having a carboxyl group in the molecule can be used. In particular, a carboxyl group-containing photosensitive resin having an ethylenically unsaturated double bond in the molecule is preferable from the viewpoint of photocurability and development resistance. The ethylenically unsaturated double bonds are preferably derived from acrylic acid or methacrylic acid or derivatives thereof. When only a carboxyl group-containing resin having no ethylenically unsaturated double bonds is used, in order to make the composition photocurable, a compound having a plurality of ethylenically unsaturated groups in the molecule described later, that is, photo It is necessary to use a polymerizable monomer together. Specific examples of carboxyl group-containing resins include the following compounds (both oligomers and polymers). Carboxyl group-containing resins may be used alone or in combination of two or more.

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

(2) Diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates and aromatic diisocyanates; Polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, carboxyl group-containing urethane resins obtained by polyaddition reaction of diol compounds such as compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

(3) a diisocyanate, a bifunctional epoxy resin such as a bisphenol A type epoxy resin, a hydrogenated bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a bixylenol type epoxy resin, or a biphenol type epoxy resin ( Carboxyl group-containing photosensitivity obtained by polyaddition reaction of partial acid anhydride-modified reaction product with monocarboxylic acid compound having ethylenically unsaturated double bond such as meth)acrylic acid, carboxyl group-containing dialcohol compound and diol compound Urethane resin.

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

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

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

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

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

(9) an epoxy compound having a plurality of epoxy groups in one molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, such as p-hydroxyphenethyl alcohol; Maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and adipine are reacted with an unsaturated group-containing monocarboxylic acid such as acrylic acid, and the alcoholic hydroxyl group of the resulting reaction product is treated with A carboxyl group-containing photosensitive resin obtained by reacting a polybasic acid anhydride such as an acid.

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

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

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

The acid value of the carboxyl group-containing resin is preferably 30-150 mgKOH/g. By setting the acid value of the carboxyl group-containing resin to 30 mgKOH/g or more, the alkali development becomes good. Also, by setting the acid value to 150 mgKOH/g or less, it is possible to facilitate drawing of a good resist pattern. The acid value of the carboxyl group-containing resin is more preferably 50-130 mgKOH/g.

In addition, although the weight average molecular weight of the carboxyl group-containing resin varies depending on the resin skeleton, it is generally preferably in the range of 2,000 to 150,000, more preferably 5,000 to 100,000. If the weight-average molecular weight is less than 2,000, the moisture resistance of the coating film after exposure may be poor, causing film thinning during development and greatly deteriorating resolution. On the other hand, when the weight-average molecular weight exceeds 150,000, the developability may be remarkably deteriorated, and the storage stability may also be deteriorated. Weight average molecular weight can be measured by gel permeation chromatography (GPC).

The blending amount of the carboxyl group-containing resin is preferably 20 to 60% by mass in terms of solid content in the resin composition. By making it 20% by mass or more, the strength of the coating film can be improved. Moreover, by making it 60% by mass or less, the viscosity becomes appropriate and the processability improves. The content of the carboxyl group-containing resin is more preferably 30 to 50% by mass.

(Photopolymerizable monomer)
A photopolymerizable monomer can be blended in the resin composition. A photopolymerizable monomer is a monomer having an ethylenically unsaturated double bond. The photopolymerizable monomer, especially when using a carboxyl group-containing non-photosensitive resin that does not have an ethylenically unsaturated double bond, must be used in combination with a photopolymerizable monomer to make the composition photocurable. Therefore, it is valid.

Examples of photopolymerizable monomers include commonly known polyester (meth)acrylates, polyether (meth)acrylates, urethane (meth)acrylates, carbonate (meth)acrylates, epoxy (meth)acrylates, and the like. Specifically, alkyl acrylates such as 2-ethylhexyl acrylate and cyclohexyl acrylate; hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; alkylene glycols such as ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol. mono- or diacrylates of oxide derivatives; acrylamides such as N,N-dimethylacrylamide, N-methylolacrylamide and N,N-dimethylaminopropylacrylamide; N,N-dimethylaminoethyl acrylate, N,N-dimethylaminopropyl Aminoalkyl acrylates such as acrylates; Polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol and trishydroxyethyl isocyanurate, or their alkylene oxide adducts or ε-caprolactone adducts, etc. polyvalent acrylates; phenols such as phenoxy acrylate and bisphenol A diacrylate or polyvalent acrylates such as alkylene oxide adducts thereof; glycidyls such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate Ether acrylates; not limited to the above, acrylates and melamine acrylates obtained by directly acrylated polyols such as polyether polyols, polycarbonate diols, hydroxyl-terminated polybutadiene, and polyester polyols, or urethane acrylated via diisocyanate, and the above acrylates can be appropriately selected from at least one of the methacrylates corresponding to and used. Such photopolymerizable monomers can also be used as reactive diluents. One type of the photopolymerizable monomer may be used alone, or two or more types may be used in combination.

The blending amount of the photopolymerizable monomer is preferably 10 to 100 parts by mass in terms of solid content with respect to 100 parts by mass of the carboxyl group-containing resin. When the amount of the photopolymerizable monomer is 10 parts by mass or more, the photocurability is good, and pattern formation is facilitated in alkali development after irradiation with active energy rays. On the other hand, when the content is 100 parts by mass or less, halation is less likely to occur and good resolution can be obtained.

(Photoinitiator)
Any known photopolymerization initiator can be used in the resin composition. A photoinitiator may be used individually by 1 type, and may be used in combination of 2 or more type.

Specific examples of photopolymerization initiators include bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis -(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide , bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2, bisacylphosphine oxides such as 4,6-trimethylbenzoyl)-phenylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethyl monoacylphosphine oxides such as benzoylphenylphosphinate methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinate isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide; phenyl ( 2,4,6-trimethylbenzoyl)ethylphosphinate, 1-hydroxy-cyclohexylphenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1- one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, 2-hydroxy-2-methyl-1 - hydroxyacetophenones such as phenylpropan-1-one; benzoins such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether; benzoin alkyl ethers; 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-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethyl Amino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl)-1-[4-(4-morpholinyl)phenyl]-1- Acetophenones such as butanone and N,N-dimethylaminoacetophenone; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropyl Thioxanthones such as thioxanthone; anthraquinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; acetophenone dimethyl ketal , ketals such as benzyl dimethyl ketal; ethyl-4-dimethylaminobenzoate, 2-(dimethylamino) ethyl benzoate, benzoic acid esters such as p-dimethylbenzoic acid ethyl ester; 1,2-octanedione, 1-[ 4-(phenylthio)phenyl]-,2-(O-benzoyloxime), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(O -acetyloxime); bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, bis Titanocenes such as (cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyr-1-yl)ethyl)phenyl]titanium; phenyl disulfide 2-nitrofluorene, butyroin, anisoin Ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide and the like can be mentioned.

The amount of the photopolymerization initiator (excluding the oxime ester-based photopolymerization initiator) in the resin composition is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin. When the content is 1 part by mass or more, the photocurability of the resin composition is improved, the film is difficult to peel off, and the film properties such as chemical resistance are improved. On the other hand, when the content is 20 parts by mass or less, the effect of reducing outgassing is obtained, the light absorption on the surface of the solder resist coating film is improved, and the deep-part curability is less likely to deteriorate. More preferably, it is 3 to 10 parts by mass. The amount of the oxime ester photopolymerization initiator in the resin composition is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin. When the amount is 0.1 part by mass or more, the resin composition has good photocurability and good film properties such as heat resistance and chemical resistance. On the other hand, when the amount is 20 parts by mass or less, the light absorption of the solder resist film is improved, and the deep-part curability is less likely to deteriorate. More preferably, it is 0.5 to 10 parts by mass.

A photoinitiation aid or a sensitizer may be used in combination with the photopolymerization initiator described above. Photoinitiation aids or sensitizers include benzoin compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds, xanthone compounds, and the like. Thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, and 4-isopropylthioxanthone are particularly preferred. Inclusion of a thioxanthone compound can improve deep-part curability. These compounds can be used as a photopolymerization initiator in some cases, but are preferably used in combination with the photopolymerization initiator. The photoinitiation aid and the sensitizer may be used singly or in combination of two or more.

In addition, since these photopolymerization initiators, photoinitiator aids, and sensitizers absorb specific wavelengths, the sensitivity may be lowered in some cases, and they may function as ultraviolet absorbers. However, these are not used only for the purpose of improving the sensitivity of the composition. It absorbs light of a specific wavelength as needed to increase the photoreactivity of the surface, change the line shape and opening of the resist to vertical, tapered, and reverse tapered shapes, and improve the accuracy of the line width and opening diameter. can be improved.

(Thermosetting component)
The resin composition may contain a thermosetting component. By including a thermosetting component in the resin composition, it can be expected that the heat resistance of the resin composition is improved. Examples of thermosetting components include known and commonly used ones such as isocyanate compounds, blocked isocyanate compounds, amino resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy compounds, oxetane compounds, and episulfide resins. Preferred thermosetting components among these are epoxy resins. A thermosetting component may be used individually by 1 type, and may be used in combination of 2 or more type.

Epoxy resins that can be used include, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin. resins, cresol novolak-type epoxy resins, bisphenol A novolac-type epoxy resins, biphenyl-type epoxy resins, naphthalene-type epoxy resins, dicyclopentadiene-type epoxy resins, triphenylmethane-type epoxy resins, and the like.

Examples of commercially available epoxy resins include jER 828, 806, 807, YX8000, YX8034, 834 manufactured by Mitsubishi Chemical Corporation, YD-128, YDF-170, ZX-1059 manufactured by Nippon Steel Chemical & Materials Co., Ltd. Examples include ST-3000, EPICLON 830, 835, 840, 850, N-730A and N-695 manufactured by DIC Corporation, and RE-306 manufactured by Nippon Kayaku Co., Ltd.

(curing agent)
The resin composition may contain a curing agent. As the curing agent contained in the resin composition, known curing agents that are commonly used for curing the above-described thermosetting resins can be used. For example, amines, imidazoles, polyfunctional phenols , acid anhydrides, isocyanates, imidazole latent curing agents such as imidazole adducts, and polymers containing these functional groups. Examples of amines include dicyandiamide and diaminodiphenylmethane. Examples of imidazoles include alkyl-substituted imidazoles and benzimidazoles. Examples of polyfunctional phenols include hydroquinone, resorcinol, bisphenol A and their halogen compounds, and condensates of these with aldehydes such as novolak and resole resins. Acid anhydrides include, for example, phthalic anhydride, hexahydrophthalic anhydride, methylnadic anhydride, benzophenonetetracarboxylic acid and the like. Isocyanates include, for example, tolylene diisocyanate and isophorone diisocyanate, and those isocyanates masked with phenols or the like can also be used. The curing agents may be used singly or in combination of two or more. As the curing agent, imidazoles are preferably used.

Examples of imidazoles include reaction products of epoxy resins and imidazole, and specific examples include 2-methylimidazole, 4-methyl-2-ethylimidazole, 2-phenylimidazole, 4-methyl-2-phenyl imidazole, 1-benzyl-2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-un decyl imidazole and the like. Commercial products of imidazoles include, for example, imidazoles such as 2E4MZ, C11Z, C17Z, and 2PZ (reaction products of epoxy resin and imidazole), 2MZ-A, 2E4MZ-A, and 2MZA-PW (above, imidazole AZINE (azine) compound), 2MZ-OK, 2PZ-OK (above, isocyanurate of imidazole), 2PHZ, 2P4MHZ (above, imidazole hydroxymethyl) (all of these are manufactured by Shikoku Kasei Co., Ltd.) etc. Examples of commercially available imidazole-type latent curing agents include CURESOL P-0505 (manufactured by Shikoku Kasei Kogyo Co., Ltd.).

(Inorganic filler)
The resin composition may contain an inorganic filler. As the inorganic filler, known inorganic fillers can be used, and barium sulfate, spherical silica, hydrotalcite and talc are preferably used. These may be used individually by 1 type, and may be used in combination of 2 or more type. Spherical silica is particularly preferably used as the inorganic filler.

Any spherical silica that can be used as a filler for electronic materials can be used as the spherical silica. The shape of the spherical silica is not limited to being spherical as long as it is spherical. Examples of suitable spherical silica include, but are not limited to, those having a sphericity of 0.8 or more measured as follows.

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

Although the average particle size of the spherical silica is not particularly limited, it is preferably 0.05-10 μm, more preferably 0.1-5 μm, and still more preferably 0.3-1 μm. The average particle size of spherical silica is the average particle size (D50) including not only the particle size of primary particles but also the particle size of secondary particles (aggregates), and the value of D50 measured by a laser diffraction method. is. Microtrac MT3300EXII manufactured by Microtrac Bell Co., Ltd. can be used as a measuring device using the laser diffraction method. The maximum particle size (D100) and particle size (D10) can also be measured in the same manner using the above apparatus. Further, the average particle size of the spherical silica contained in the resin composition layer is the value obtained by measuring the spherical silica as described above before adjusting (preliminarily stirring, kneading) the resin composition constituting the resin composition layer. shall mean.

The above inorganic filler may be surface-treated. As the surface treatment, a surface treatment with a coupling agent, or a surface treatment that does not introduce an organic group, such as alumina treatment, may be performed. The surface treatment method of the inorganic filler is not particularly limited, and a known and commonly used method may be used, and the inorganic filler is treated with a surface treatment agent having a curable reactive group, such as a coupling agent having a curable reactive group as an organic group. surface should be treated.

The surface treatment is preferably surface treatment with a coupling agent. As the coupling agent, silane-based, titanate-based, aluminate-based, and zirco-aluminate-based coupling agents can be used. Among them, silane coupling agents are preferred. Examples of such silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, N-(2-aminomethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-amino propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxy Cyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like can be mentioned, and these can be used alone or in combination.

The blending amount of the inorganic filler in the resin composition is preferably 85% by mass or less in terms of solid content based on the total solid content of the resin composition. When the amount of the inorganic filler is 85% by mass or less, an excessive increase in the viscosity of the resin composition can be suppressed, good coatability and moldability can be maintained, and the cured product can be It can have sufficient strength. The range of the amount of the inorganic filler compounded is preferably 30 to 85% by mass, more preferably 40 to 80% by mass, and still more preferably 50 to 75% by mass in terms of solid content based on the total solid content of the resin composition. %. When the amount of the inorganic filler to be blended is within the above range, good physical properties of the cured film can be obtained.

(Thermoplastic resin)
The resin composition may further contain a thermoplastic resin in order to improve the mechanical strength of the resulting cured product. The thermoplastic resin is preferably soluble in solvents. When it is soluble in a solvent, the flexibility of the film laminate is improved, and the occurrence of cracks and falling powder can be suppressed. Thermoplastic resins include thermoplastic polyhydroxy polyether resins, phenoxy resins that are condensates of epichlorohydrin and various bifunctional phenol compounds, and various acid anhydrides and acid chlorides that replace the hydroxyl groups of the hydroxy ether portion present in the skeleton. and esterified phenoxy resins, polyvinyl acetal resins, polyamide resins, polyamideimide resins, block copolymers, and the like. The thermoplastic resin may be used alone or in combination of two or more.

The blending amount of the thermoplastic resin is 0.5 to 20% by mass, preferably 0.5 to 10% by mass, relative to the entire resin composition layer. When the blending amount of the thermoplastic resin is within the above range, it is easy to obtain a uniform roughened surface state.

(Organic solvent)
The resin composition may contain an organic solvent for the purpose of its preparation and viscosity adjustment when applying the resin composition to the first film. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether; , dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, tripropylene glycol monomethyl ether; ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbi Esters such as tall acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; known petroleum solvents such as petroleum ether, petroleum naphtha, and solvent naphtha Conventional organic solvents can be used. An organic solvent may be used individually by 1 type, and may be used in combination of 2 or more type.

The boiling point of the organic solvent is not particularly limited as long as the effect of the present invention is exhibited, but from the viewpoint of ease of adjustment of the amount of residual solvent in the film laminate, preferably 50 to 220 ° C., more preferably 50 to 150 °C. In the present invention, the term "residual solvent" means that after forming a resin composition layer on the surface of the first film, it is dried at 75°C for 15 minutes to volatilize the solvent. The amount of solvent that is removed (i.e., remains).

Volatilization drying of organic solvents is carried out by using a hot air circulating drying furnace, IR furnace, hot plate, convection oven, etc. (equipped with a heat source that heats the air using steam), and a method in which the hot air in the dryer is brought into contact with the counter current and supported by a nozzle. method of spraying on the body) can be used.

The amount of the organic solvent blended in the resin composition can be appropriately changed according to the materials constituting the resin composition. The amount of is based on the total amount of the resin composition layer of the film laminate (that is, the resin composition layer after forming the resin composition layer on the surface of the film and drying at 75 ° C. for 15 minutes), 0 .1 to 4% by mass, more preferably 0.3 to 3% by mass. When the amount of residual solvent is within the above range, the film can be easily peeled off. The amount of residual solvent can be adjusted by appropriately selecting the boiling point of a suitable organic solvent and the blending amount of the organic solvent in the resin composition. Although the method for measuring the amount of residual solvent is not particularly limited, examples thereof include the measuring method described in Examples.

(other ingredients)
The resin composition layer may further optionally contain conventionally known colorants such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, asbestos, orben, Conventionally known thickeners such as bentone and finely divided silica; antifoaming agents and/or leveling agents such as silicone-based, fluorine-based and polymer-based agents; adhesion imparting agents such as thiazole-based, triazole-based and silane coupling agents , flame retardants, organic fillers, rubber-like particles, sensitizers, titanate-based and aluminum-based conventionally known additives.

[Manufacturing method of film laminate]
The film laminate of the present invention can be produced by applying the resin composition described above onto the first film described above and drying it to form a resin composition layer. Specifically, the resin composition that constitutes the resin composition layer is diluted with an organic solvent to adjust the viscosity to an appropriate value, and then applied by a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, a reverse coater, and a transfer roll coater. , gravure coater, spray coater, etc., to a uniform thickness on the first film, and usually dried at a temperature of 50 to 130 ° C. for 1 to 30 minutes to volatilize the organic solvent in the resin composition. , a resin composition layer can be formed. The coating amount of the resin composition is not particularly limited, but is generally selected appropriately within the range of 1 to 150 μm, preferably 10 to 60 μm, in terms of film thickness after drying.

The drying performed after applying the resin composition is mainly performed to volatilize the solvent contained in the resin composition (evaporation drying). Drying is carried out by using a hot air circulating drying furnace, IR furnace, hot plate, convection oven, etc. (equipped with a heat source of air heating method using steam), and a method in which the hot air in the dryer is brought into contact with the counter current, and is blown onto the support from a nozzle. method) can be used.

After forming the resin composition layer on the first film, a second film that can be peeled off from the surface of the resin composition layer for the purpose of preventing dust from adhering to the surface of the resin composition layer. is preferably laminated. The second film refers to a film that separates from the resin composition layer before lamination when the film laminate is laminated by heating or the like so that the resin composition layer side of the film laminate is in contact with a base material such as a substrate and integrally molded. . As the peelable second film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used. It is sufficient that the adhesive strength between the resin composition layer and the second film is smaller than the adhesive strength with the first film.

The thickness of the second film is not particularly limited, but can be, for example, 10 μm to 150 μm.

[Cured product]
The cured product of the present invention is obtained by curing the resin composition layer of the film laminate of the present invention described above. The cured product of the present invention is preferably a solder resist layer, particularly a matte solder resist layer, having a thickness of 1 to 150 μm, for example.

[Printed wiring board]
The printed wiring board of the present invention has a cured product obtained from the resin composition layer of the film laminate of the present invention described above. In the method for producing a printed wiring board of the present invention, for example, the resin composition layer of the film laminate is laminated on the substrate by a laminator or the like so as to be in contact with the substrate, and then the first film is peeled off. to form a resin composition layer on the substrate. In addition, a patterned cured product can be formed on the base material by peeling off the first film after the exposure described later and performing development as long as the properties are not impaired.

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

The lamination of the film laminate onto the substrate is preferably carried out under pressure and heat using a vacuum laminator or the like. By using such a vacuum laminator, even if a substrate having a circuit formed thereon is used, even if the surface of the circuit substrate is uneven, the film laminate adheres to the circuit substrate. , the hole-filling property of the concave portion of the substrate surface is also improved. The pressure condition is preferably about 0.1 to 2.0 MPa, and the heating condition is preferably 40 to 120°C.

After forming a resin composition layer on the substrate, it is selectively exposed to active energy rays through a photomask having a predetermined pattern, and the unexposed area is treated with a dilute alkaline aqueous solution (for example, 0.3 to 3% by mass sodium carbonate. aqueous solution) to form a patterned cured product on the substrate. Before exposure, the first film may be peeled off from the film laminate, and the exposed resin composition layer may be exposed and developed as long as the properties are not impaired. Furthermore, after irradiating the cured product with active energy rays, heat curing (e.g., 100 to 220 ° C), or after heat curing, irradiating the active energy rays, or final final curing (main curing) only by heat curing. Forms a cured coating film with excellent properties such as toughness and hardness.

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

As a developing method, a dipping method, a shower method, a spray method, a brush method, or the like can be used. , amines, etc. can be used.

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

Films 1 to 4 below were prepared as films (first films) constituting the film laminate.
Film 1: A polyethylene terephthalate film (thickness: 38 μm, arithmetic mean roughness Ra: 0.04 μm, maximum height Rz: 0.88 μm) prepared according to the procedure described in the preparation of film 1 below.
Film 2: A polyethylene terephthalate film (film thickness: 42 μm, arithmetic mean roughness Ra: 0.16 μm, maximum height Rz: 3.28 μm) prepared according to the procedure described in the preparation of film 2 below.
Film 3: A polyethylene terephthalate film (thickness: 42 μm, arithmetic mean roughness Ra: 0.22 μm, maximum height Rz: 4.16 μm) prepared according to the procedure described in the preparation of film 3 below.
Film 4: commercially available polypropylene film Alphan MA-411 (manufactured by Oji F-Tex Co., Ltd.)
(Film thickness: 15 µm, arithmetic mean roughness Ra: 0.20 µm, maximum height Rz: 1.77 µm)

<Preparation of Film 1>
Film 1 described above was produced according to the following procedure.
After the polyethylene terephthalate resin was melt extruded at 290°C, the extruded molten polyethylene terephthalate resin was cooled and solidified on a cooling roll whose surface temperature was set to 40°C by an electrostatic contact method to obtain an unstretched sheet. Next, the unstretched sheet is stretched in the roll winding direction (longitudinal direction) at 90° C., stretched in the transverse direction at 110° C. through a preheating step in a tenter, heat-treated for 10 seconds, and then 180° C. °C in the width direction to obtain a biaxially stretched polyester film (film 1). The film thickness of the film 1 was 38 μm.

In addition, the arithmetic mean roughness Ra and the maximum height Rz of the surface of the film 1 were measured in accordance with JIS B 0601: 2001 using a shape measuring laser microscope VX-100 (manufactured by Keyence Corporation) in shape measurement mode. It was measured. Specifically, in the shape measurement mode of the shape measurement laser microscope, launch the observation application VK-H1XV, place the film 1 on the XY stage, use the 50x objective lens, and use the shape measurement mode Focused with autofocus. The Z-axis was controlled as necessary to adjust the focus to the optimum position. Then, the observed image was captured in automatic measurement mode or manual measurement mode. Next, we launched the analysis application VK-H1XA and measured the arithmetic mean roughness and maximum height. Film 1 had an arithmetic mean roughness Ra of 0.04 μm and a maximum height Rz of 0.88 μm.

<Preparation of film 2 (coating type)>
Film 2 described above was produced according to the following procedure.
Methyl methacrylate, methyl acrylate, and 8-hydroxyoctyl methacrylate were blended so that the blending ratio in terms of solid content was 95:5:3.0 on a mass basis, prestirred using a stirrer, and diluted with ethyl acetate. As a result, a resin solution having a solid concentration of 35% by mass was obtained. Next, azobisisobutyronitrile as a polymerization initiator and Coronate (registered trademark) HX as a cross-linking agent were added dropwise to the obtained resin solution at a ratio of 1:30 on a mass basis, and then heated to 65°C. It was heated and reacted for a predetermined time to obtain an acrylic resin solution.

Next, to the obtained acrylic resin solution, after adding ethyl acetate so that the solid content concentration is appropriate according to the desired thickness of the coating film, silicone resin Cymac US-270 (manufactured by Toagosei Co., Ltd.) and spherical silica SO-C2 (manufactured by Admatechs Co., Ltd.) so that the mixing ratio of acrylic resin, silicone resin and filler in terms of solid content is 59.7:0.3:6.2 on a mass basis. and thoroughly stirred at room temperature using a stirrer to obtain a homogeneous resin solution. Next, the obtained resin solution was applied to Film 1 described above and dried at 130° C. for 20 seconds to obtain Film 2 having a coating layer. The film thickness of the film 2 was 42 μm.

In addition, the arithmetic mean roughness Ra and maximum height Rz of the surface of film 2 were measured in the same manner as the measurement of the arithmetic mean roughness and maximum height of film 1 described above. Film 2 had an arithmetic mean roughness Ra of 0.16 μm and a maximum height Rz of 3.28 μm.

<Preparation of film 3 (coating type)>
Film 3 described above was produced according to the following procedure.
Isobutylated melamine resin Amidia L-125-60 (solid content 60%, manufactured by DIC Corporation) and acrylic resin Acrydic A-405 for melamine baking (solid content 50%, manufactured by DIC Corporation) are blended in terms of solid content. They were blended so that the ratio was 25:75 on a mass basis, and pre-stirred using a stirrer to obtain an acrylic melamine resin.

Next, the obtained acrylic melamine resin was diluted with methyl ethyl ketone to obtain a resin solution with a solid concentration of 35% by mass. After adding methyl ethyl ketone to the obtained resin solution so that the solid content concentration is appropriate according to the desired thickness of the coating film, silicone resin Cymac US-270 (manufactured by Toagosei Co., Ltd.) and spherical silica SO- C2 (manufactured by Admatechs Co., Ltd.) was added so that the mixing ratio of acrylic melamine resin, silicone resin and filler in terms of solid content was 59.7: 0.3: 16.0 on a mass basis. was used to sufficiently stir at room temperature to obtain a homogeneous resin solution. The resulting resin solution was applied to film 1 described above and dried at 130° C. for 20 seconds to obtain film 3 having a coating layer. The film thickness of the film 3 was 42 μm.

In addition, the arithmetic mean roughness Ra and maximum height Rz of the surface of film 3 were measured in the same manner as the measurement of the arithmetic mean roughness and maximum height of film 1 described above. Film 3 had an arithmetic mean roughness Ra of 0.22 μm and a maximum height Rz of 4.16 μm.

As the resin composition constituting the film laminate, resin compositions 1 to 5 were prepared according to the following procedure.

<Synthesis of carboxyl group-containing resin A>
A carboxyl group-containing resin A was synthesized according to the following procedure.
First, an autoclave equipped with a thermometer, a nitrogen introduction device, an alkylene oxide introduction device, and a stirring device was charged with 119 novolak cresol resin (trade name "Shonol CRG951", manufactured by Aica Kogyo Co., Ltd., OH equivalent: 119.4). 4 parts by mass, 1.19 parts by mass of potassium hydroxide, and 119.4 parts by mass of toluene were introduced, and the inside of the system was replaced with nitrogen while stirring, and the temperature was raised. Next, 63.8 parts by mass of propylene oxide was gradually added dropwise and reacted at 125 to 132° C. and 0 to 4.8 kg/cm 2 for 16 hours. Thereafter, the reaction solution was cooled to room temperature, 1.56 parts by mass of 89% phosphoric acid was added to the reaction solution, and the potassium hydroxide was neutralized while mixing to obtain a propylene oxide reaction solution of a novolac type cresol resin [solid content: 62.5 g]. 1%; hydroxyl value: 182.2 mgKOH/g (307.9 g/eq.)]. This propylene oxide reaction solution contained an average of 1.08 mol of propylene oxide per equivalent of phenolic hydroxyl group.

293.0 parts by mass of the propylene oxide reaction solution of the obtained novolak-type cresol resin, 43.2 parts by mass of acrylic acid, 11.53 parts by mass of methanesulfonic acid, 0.18 parts by mass of methylhydroquinone and 252.9 parts by mass of toluene , a stirrer, a thermometer and an air blowing tube, and air was blown in at a rate of 10 ml/min to react at 110° C. for 12 hours while stirring.

12.6 parts by mass of water produced by the reaction was distilled as an azeotrope with toluene. After cooling to room temperature, the resulting reaction solution was neutralized with 35.35 parts by mass of a 15% aqueous sodium hydroxide solution and then washed with water. After that, 118.1 parts by mass of propylene glycol monomethyl ether acetate (PMA) was distilled off using an evaporator while substituting toluene to obtain a novolak type acrylate resin solution. Next, 332.5 parts by mass of the obtained novolak-type acrylate resin solution and 1.22 parts by mass of triphenylphosphine were introduced into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was added at 10 ml/ 60.8 parts by mass of tetrahydrophthalic anhydride was gradually added while stirring at a rate of 10 minutes, reacted at 95 to 101° C. for 6 hours, and taken out after cooling. Thus, a solution of carboxyl group-containing resin A (solid content: 70.6%; acid value of solid content: 87.7 mgKOH/g) was obtained.

<Synthesis of silica slurry>
A silica slurry was synthesized according to the following procedure.
Dispersion treatment was performed using 700 g of spherical silica (manufactured by Admatec Co., Ltd.), 300 g of PMA as a solvent, and 0.7 μm zirconia beads in a bead mill. This was repeated three times and filtered through a 3 μm filter to prepare a silica slurry having an average particle size of 0.7 μm. The solid content of the obtained silica slurry was 70% by mass.

<Preparation of resin composition>
Each component shown in Table 1 below was blended and thoroughly stirred. Then, the mixture was kneaded using a three-roll mill or a bead mill to obtain Resin Compositions 1-8. In addition, the numerical value of each component in a table|surface shows a mass part (solid content conversion).

<Measurement of viscosity>
1.0 ml of the resin compositions 1 to 8 prepared according to the procedure described above were sampled and measured at 25° C. using a cone/plate viscometer TV-33H (rotor 1°34′×R24, manufactured by Toki Sangyo Co., Ltd.). The viscosity was measured after rotating at 5 rpm (shear rate 10-1 s) for 30 seconds. Table 1 shows the measurement results.

<Measurement of amount of residual solvent>
On the surface of film 1 described above, resin compositions 1 to 8 prepared according to the procedure described above were used to form a resin composition layer having a length of 15 cm, a width of 8 cm, and a film thickness of 20 μm with an applicator having a gap of 50 μm. Then, the resin composition layer on each film 1 was dried at 75° C. for 15 minutes to obtain each film laminate having a dried resin composition layer. On the other hand, a copper foil (F2-WS, manufactured by Furukawa Electric Co., Ltd.) was cut into a size of 15 cm long×9.5 cm wide, and the weight (A) was measured with an electronic balance. Each film laminate and copper foil prepared by the procedure described above are attached so that the resin composition and copper foil of each film laminate are in contact, and the film 1 is peeled off from each film laminate to obtain a resin composition. A copper foil with a layer was obtained. The weight (B) of each copper foil having a resin composition layer was measured with an electronic balance. Next, each copper foil having a resin composition layer is placed on a glass epoxy substrate and fixed with a clip, the resin composition layer is dried at 100 ° C. for 20 minutes, and the solvent ( residual solvent) was evaporated. Next, each copper foil having a resin composition layer is allowed to cool at room temperature for 20 minutes, the weight (C) after cooling is measured with an electronic balance, and the resin composition layer of each copper foil is cooled at 100 ° C. for 20 minutes. The mass of the solvent volatilized by drying (that is, the residual solvent in the resin composition layer of each copper foil) is calculated by Equation 1, and the amount of residual solvent (% by mass) is calculated by Equation 2 based on the calculated mass. asked for For each resin composition, three film laminates were produced and weighed, and the average is shown in Table 1.
(Formula 1) Mass [g] of residual solvent (solvent volatilized by drying at 100 ° C. for 20 minutes) = (B) - (C)
(Formula 2) Amount of residual solvent [% by mass] = {(B) - (C)} / {(B) - (A)} x 100

<Measurement of contact angle at 25°C>
The contact angle (contact angle A) between each film and each resin composition at 25°C was measured according to JIS R3257:1999.
Specifically, the multifunctional integrated analysis software FAMAS (manufactured by Kyowa Interface Science Co., Ltd.) was activated to activate the CA/PD controller. At that time, the "field of view" on the controller screen was selected as "standard". Put each resin composition described above at a measurement temperature of 25 ° C. in a plastic syringe, attach a stainless steel needle (22 gauge) to the tip of the syringe, and drop 2.5 μL of each resin composition onto each film described above. A droplet formed. During dropping, it was confirmed that the camera attached to the automatic contact angle meter DMo-601 (manufactured by Kyowa Interface Science Co., Ltd.) was in focus. An image of the droplet was taken from the horizontal side, and the contact angle of the droplet at the film interface of the obtained image was analyzed. In order to take an image of the droplet and analyze the contact angle after the shape of the droplet of the resin composition is stabilized, the droplet of the resin composition adheres (drops) on the film. Seconds later, the droplet was photographed. In addition, the contact angle was analyzed for five arbitrary droplets for each resin composition on one type of film. The contact angle (contact angle A) at 25° C. between each film and each resin composition is shown in Table 2 below. In addition, in Table 2, the value of each contact angle A is the average value for five droplets.

<Measurement of contact angle at 75°C>
Then, the contact angle (contact angle B) between each film and each resin composition at 75° C. was measured according to JIS R3257:1999.
Specifically, each resin composition described above at a measurement temperature of 25 ° C. was put into a plastic syringe, and a stainless steel needle (22 gauge) heated to a temperature of 75 ° C. was attached to the tip of the plastic syringe, and 2.5 μL of each resin composition was added. was dropped onto each film heated to a temperature of 75° C. to form droplets. The contact angle between each film and each resin composition at 75° C. was measured by the same method as the measurement of the contact angle A described above. In addition, the photographing of the droplet image and the analysis of the contact angle were performed for five arbitrary droplets for each resin composition on one type of film. The contact angle (contact angle B) at 75° C. between each film and each resin composition is shown in Table 2 below. In addition, in Table 2, the value of each contact angle B is the average value for five droplets.

From the results shown in Table 2, the contact angle (contact angle A) between the film and the resin composition at 25°C and the contact angle (contact angle B) between the film and the resin composition at 75°C were evaluated based on the following criteria. bottom. Table 3 shows the evaluation results.
○: The contact angles A and B satisfy both 15°≦A≦30° and 0.75A≦B≦1.3A.
x: The contact angles A and B do not satisfy at least one of 15°≦A≦30° and 0.75A≦B≦1.3A.

<Evaluation of suppression of flipping>
According to the following procedures, suppression of repelling was evaluated when each resin composition was applied onto each film.
First, each film was cut into a length of 30 cm and a width of 15 cm. Then, each resin composition was used to form a resin composition layer of 20 cm long×8 cm wide×20 μm thick on the surface of each cut film using an applicator having a gap of 50 μm. Next, the resin composition on each film was dried at 75° C. for 15 minutes to obtain each film laminate having a dried resin composition layer. Each obtained film laminate was visually observed, and suppression of flipping of the resin composition in each film laminate was evaluated based on the following criteria. Table 4 shows the evaluation results.
A: Repelling of the resin composition on the surface of the film laminate is remarkably suppressed.
◯: Repelling of the resin composition on the surface of the film laminate is sufficiently suppressed.
Δ: Repelling of the resin composition on the surface of the film laminate is not sufficiently suppressed.
x: Repelling of the resin composition on the surface of the film laminate is hardly suppressed.

From the results shown in Tables 3 and 4, the contact angle (contact angle A) between the film and the resin composition at 25°C and the contact angle (contact angle B) at 75°C are
15°≤A≤30°
0.75A≤B≤1.3A
It can be seen that the repelling of the resin composition on the film is satisfactorily suppressed when both are satisfied.

<Evaluation of suppression of color unevenness>
Suppression of color unevenness when each resin composition was applied onto each film was evaluated according to the following procedure.
First, each film was cut into a length of 30 cm and a width of 15 cm. Then, each resin composition was used to form a resin composition layer of 20 cm long×8 cm wide×20 μm thick on the surface of each cut film using an applicator having a gap of 50 μm. Next, the resin composition on each film was dried at 75° C. for 15 minutes to obtain each film laminate having a dried resin composition layer. The L*a*b* values of the lightest and darkest color tone portions were measured for a region of 14 cm long×6 cm wide in the center of the resin composition layer in each film laminate obtained. Specifically, each film laminate is placed on a white plate so that the film surface of each film laminate is in contact with the white plate, and a spectral side colorimeter CM-2600d (manufactured by Konica Minolta Japan Co., Ltd.) is used. Then, the L*a*b* value (SCE method, standard light source D65, visual field 10 deg.) of the resin composition of each film laminate was measured. The color difference (ΔE*ab) between the lightest color tone portion and the darkest color tone portion within the measurement range was calculated based on Equation 1 below. As the white plate, a white plate having L*a*b* values of L*: 94.3, a*: -0.6, and b*: 2.8 was used.

Next, from the calculated color difference (ΔE*ab) of the resin composition of each film laminate, suppression of color unevenness of the resin composition layer in each film laminate was evaluated based on the following criteria. Table 5 shows the evaluation results.
A: The color difference is ΔE*ab<3.0, and the color unevenness of the resin composition layer on the surface of the film laminate is remarkably suppressed.
◯: Color difference is 3.0≦ΔE*ab<4.5, and color unevenness of the resin composition layer of the film laminate is sufficiently suppressed.
Δ: The color difference is 4.5≦ΔE*ab<6.0, and the color unevenness of the resin composition layer of the film laminate is not sufficiently suppressed.
x: The color difference is 6.0≦ΔE*ab, and the color unevenness of the resin composition layer of the laminate of the film laminate is hardly suppressed.

From the results shown in Tables 3 and 5, the contact angle (contact angle A) at 25° C. and the contact angle (contact angle B) at 75° C. between the film and the resin composition are
15°≤A≤30°
0.75A≤B≤1.25A
It can be seen that when both conditions are satisfied, the color unevenness of the resin composition layer on the film is suppressed satisfactorily.

From the results shown in Tables 3 to 5, the contact angle (contact angle A) at 25° C. and the contact angle (contact angle B) at 75° C. between the film and the resin composition are
15°≤A≤30°
0.75A≤B≤1.3A
When both are satisfied, the repelling of the resin composition on the film when the resin composition is applied and dried is well suppressed, and as a result, the color unevenness of the resin composition layer of the film laminate is good. is considered to be suppressed by

<Evaluation of Suppression of Film Thickness Variation>
Suppression of film thickness non-uniformity (film thickness variation) when each resin composition was applied onto each film was evaluated according to the following procedure.
First, in the area of 14 cm long × 6 cm wide in the center of the resin composition of each film laminate used in the evaluation of the suppression of color unevenness described above, the film thickness of the lightest and darkest color tone portions was measured using a laser microscope VK. -X100 (manufactured by KEYENCE CORPORATION) was used to observe at a magnification of 10 times. Next, the film thickness of each portion is measured, and the difference between the film thickness of the darkest color tone portion and the film thickness of the lightest color tone portion (film thickness of the darkest color tone portion - film thickness of the lightest color tone portion ) was calculated. From the calculated film thickness difference, suppression of film thickness variation of the resin composition layer in each film laminate was evaluated based on the following criteria. Table 6 shows the evaluation results.
A: The film thickness difference is less than 2.0 µm, and the film thickness variation is remarkably suppressed in the resin composition layer of the film laminate.
◯: The film thickness difference is 2.0 μm or more and less than 3.0 μm, and the film thickness variation of the resin composition layer of the film laminate is sufficiently suppressed.
Δ: The film thickness difference is 3.0 μm or more and less than 4.0 μm, and the film thickness variation of the resin composition layer of the film laminate is not sufficiently suppressed.
x: The film thickness difference is 4.0 μm or more, and the film thickness variation of the resin composition layer of the film laminate is hardly suppressed.

From the results shown in Tables 3 and 6, the contact angle (contact angle A) between the film and the resin composition at 25°C and the contact angle (contact angle B) at 75°C are
15°≤A≤30°
0.75A≤B≤1.3A
It can be seen that when both of the above conditions are satisfied, the film thickness variation of the resin composition layer on the film is suppressed satisfactorily.

From the results shown in Tables 3 to 4 and 6, the contact angle (contact angle A) between the film and the resin composition at 25 ° C. and the contact angle (contact angle B) at 75 ° C.
15°≤A≤30°
0.75A≤B≤1.3A
When both are satisfied, the repelling of the resin composition on the film when the resin composition is applied and dried is well suppressed, and as a result, the film thickness variation of the resin composition layer of the film laminate is reduced. It is considered to be well suppressed.

In general, if the uniformity of the thickness of the resin composition layer for forming the solder resist (smoothness of the resin composition layer) is insufficient, the solder resist may not exhibit sufficient performance. Are known. As described above, in a film laminate comprising a film and a resin composition layer provided on the surface thereof, the contact angle (contact angle A) between the film and the resin composition at 25 ° C. and the contact angle at 75 ° C. (Contact angle B) is
15°≤A≤30°
0.75A≤B≤1.3A
When both of the above conditions are satisfied, it is possible to satisfactorily suppress variations in film thickness of the resin composition layer of the film laminate. Therefore, it is considered that a solder resist formed using such a film laminate can exhibit sufficient performance.

Claims (11)

1. A film laminate comprising a first film and a resin composition layer provided on one surface of the first film,
   A is the contact angle between the first film and the resin composition at 25°C,
   When the contact angle between the first film and the resin composition at 75°C is B,
   15°≦A≦30°, and 0.75A≦B≦1.3A,
   A film laminate that satisfies
2. The film laminate according to claim 1, wherein the resin composition has a viscosity of 1.0 to 10 dPa·s at 25°C and 5 rpm.
3. The film laminate according to claim 1 or 2, wherein the surface of the first film in contact with the resin composition layer has an arithmetic mean roughness of less than 0.2 µm.
4. The film laminate according to claim 1 or 2, wherein the maximum height of the surface of the first film in contact with the resin composition layer is less than 4.0 µm.
5. The film laminate according to claim 1 or 2, wherein the resin composition constituting the resin composition layer is a photosensitive resin composition.
6. The film laminate according to claim 1 or 2, wherein the surface of the first film in contact with the resin composition layer is surface-treated.
7. The film laminate according to claim 1 or 2, which is a dry film.
8. The film laminate according to claim 1 or 2, which is used for forming a solder resist layer.
9. The film laminate according to claim 8, wherein the solder resist layer is a matte solder resist layer.
10. A cured product obtained by curing the resin composition layer of the film laminate according to claim 1 or 2.
11. A printed wiring board comprising the cured product according to claim 10.