JP6837281B2 - Laminated film - Google Patents

Description

The present invention relates to a laminated film.

Conventionally, a laminated film (dry film) has been used as one of means for forming a protective film or an insulating layer such as a solder resist or an interlayer insulating layer provided on a printed wiring board used in an electronic device or the like (for example, Patent Documents). 1, 2) In recent years, with the thinning of substrates and the miniaturization of circuits, there is an increasing demand for laminated films for forming protective films such as solder resists and insulating layers. The laminated film has a resin layer obtained by applying a resin composition having desired properties on a support film and then performing a drying step, and generally for protecting the surface opposite to the support film. Protective film is further laminated and is distributed on the market. The protective film and the insulating layer as described above can be formed on the printed wiring board by applying the resin layer of the laminated film to the substrate (hereinafter, also referred to as “laminate”) and then performing patterning and curing treatment.

When a laminated film for forming a film is attached on a wiring board on which a circuit having a fine pattern is formed, such as a laminated film for forming a solder resist, followability to the circuit is required. Therefore, it is common to obtain a flatter film by performing vacuum laminating under heating conditions or heat pressing with a suspension plate or the like.

Japanese Unexamined Patent Publication No. 7-15119 Japanese Unexamined Patent Publication No. 2002-162736

It was found that the resin layer of the laminated film was wrinkled after a series of laminating film bonding steps. It has been found that the presence of such wrinkles causes a problem that not only the appearance is poor but also the desired characteristics such as solder heat resistance are deteriorated because the groove portion of the wrinkle becomes thinner than the designed film thickness. ..

Further, when the supporting film (or protective film) of the laminated film is peeled from the resin layer by a mechanical means, for example, an auto peeler after a series of laminating film attaching steps, the film is torn and remains on the resin layer. It turns out that it may happen. It was also found that if the film remains on the resin layer, there is a problem that development residue is generated during the development process.

Therefore, an object of the present invention is to provide a laminated film in which wrinkles are less likely to occur in the resin layer and the film is less likely to remain on the resin layer.

As a result of diligent studies in view of the above, the present inventors have used a film having a 5% elongation load per unit width at 80 ° C. of more than 90 g / mm and 500 g / mm or less, and as a resin layer, a melt viscosity at 80 ° C. However, it has been found that the above-mentioned problems can be solved by using the one having a value of 10 to 10,000 dPa · s, and the present invention has been completed.

That is, the laminated film of the present invention has (A) a resin layer and (B) a film having a 5% elongation load per unit width at 80 ° C. of more than 90 g / mm and 500 g / mm or less. The resin layer is characterized in that the melt viscosity at 80 ° C. is 10 to 10000 dPa · s.

In the laminated film of the present invention, it is preferable that the resin layer (A) is photosensitive.

In the laminated film of the present invention, it is preferable that the resin layer (A) contains an alkali-soluble resin, a photopolymerization initiator and a thermosetting resin.

The laminated film of the present invention is preferably used by being attached to the surface of a wiring board.

The laminated film of the present invention is preferably attached to the surface of the wiring board using a vacuum laminator.

The laminated film of the present invention is preferably attached to the surface of the wiring board by a laminating treatment using a vacuum laminator followed by a flattening treatment by a hot press.

The laminated film of the present invention is preferably used for forming a permanent film on a wiring board.

According to the present invention, it is possible to provide a laminated film in which wrinkles are less likely to occur in the resin layer and the film is less likely to remain on the resin layer.

It is the schematic sectional drawing which shows one Embodiment of the laminated structure of this invention schematically. It is schematic cross-sectional view which shows the other embodiment of the laminated structure of this invention schematically.

<Laminated film>
The laminated film of the present invention is a film having (A) a resin layer and (B) a 5% elongation load per unit width at 80 ° C. of more than 90 g / mm and 500 g / mm or less (hereinafter, also referred to as “(B) film”). The resin layer (A) has a melt viscosity of 10 to 10000 dPa · s at 80 ° C. It is considered that the main cause of the wrinkles of the resin layer as described above is the wrinkles generated in the unpeeled film during vacuum laminating under heating conditions or during the subsequent heat pressing. That is, after laminating the laminated film so that the resin layer is in contact with the wiring board, vacuum lamination is usually performed under heating conditions before the support film is peeled off from the resin layer. In this step, the support film is wrinkled. When it occurs, it is considered that the resin layer is also wrinkled by being transferred to the resin layer. When a film having a 5% elongation load per unit width at 80 ° C. of more than 90 g / mm and 500 g / mm or less is used, the film is less likely to wrinkle even under the temperature conditions of thermal lamination, and as a result, the resin layer is also less likely to be wrinkled. it is conceivable that.
(B) The value of the 5% elongation load per unit width at 80 ° C. is the maximum value.

The laminated film of the present invention has a structure in which (A) a resin layer and (B) a film are laminated (FIG. 1). Another resin layer may be provided between the (B) film and the (A) resin layer as long as the effects of the present invention are not impaired. The laminated film of the present invention is wired so that the (A) resin layer is located on the wiring board side and the (B) film is located on the surface layer side, that is, on the side opposite to the wiring board when viewed from the (A) resin layer. It can be used by laminating it on a substrate. As a result, even if vacuum laminating is performed under heating conditions, the resin layer (A) is less likely to wrinkle.

In the laminated film of the present invention, in order to protect the surface of the (A) resin layer, it is preferable to further laminate the (C) film on the side opposite to the (B) film (FIG. 2). The (C) film laminated in this way may be peeled off when the (A) resin layer is laminated on the wiring board. If necessary, another resin layer may be provided between the (A) resin layer and the (C) film.

In the laminated film of the present invention, by setting the 5% elongation load of the (B) film to more than 90 g / mm, not only is wrinkle less likely to occur during vacuum laminating under heating conditions as described above, but also an auto peeler is used. Even if the film (B) is peeled off by a mechanical means such as, the film residue is unlikely to occur. Further, by setting the 5% elongation load of the (B) film to more than 90 g / mm, the (C) film is provided on the opposite side of the (B) film as in the laminated film shown in FIG. However, when the laminated film is rolled, wrinkles that occur due to the balance of tension between the (B) film and the (C) film are unlikely to occur.

Further, the laminated film of the present invention has the (C) film on the opposite side to the (B) film like the laminated film shown in FIG. 2 by setting the elongation load to 500 g / mm or less. However, when the laminated film is rolled, the balance of tension between the (B) film and the (C) film makes it difficult for wrinkles to occur on the surface of the (A) resin layer on the (C) film side, and (A). ) The circuit followability of the resin layer is improved, and the resin easily enters between narrow pitches.

The elongation load is preferably more than 90 g / mm and 400 g / mm or less, and more preferably more than 90 g / mm and 300 g / mm or less.

The laminated film of the present invention has a melt viscosity of the resin layer (A) at 80 ° C. of 10 to 10000 dPa · s. When the melt viscosity is 10 dPa · s or more, the fluidity of the resin layer at the time of thermal laminating does not become too high during vacuum laminating under heating conditions, so that wrinkles are less likely to occur. When the melt viscosity is 10000 dPa · s or less, the fluidity of the resin layer at the time of vacuum laminating under heating conditions is good and the circuit followability is better, so that the resin easily enters even in a narrow pitch. The melt viscosity is preferably 50 to 5000 dPa · s, more preferably 100 to 4000 dPa · s, and even more preferably 200 to 2500 dPa · s.

Hereinafter, each configuration requirement will be described in detail.

[(A) Resin layer]
The resin layer of the laminated film of the present invention is obtained through a drying step after applying the resin composition to the support film. The resin composition is not particularly limited, and a resin composition used for forming a protective layer or an insulating layer provided on a printed wiring board such as a conventionally known solder resist, an interlayer insulating layer and a coverlay can be used. The film thickness of the resin layer is not particularly limited, but the film thickness after drying is preferably 1 to 200 μm. In the case of a photosensitive curable resin layer, when it is 200 μm or less, a decrease in deep curability can be suppressed. The resin layer contains a curable resin and a filler, and the filler content is preferably 10% by mass or more based on the total amount of the resin layer of the dry film excluding the solvent. Specific examples of the resin composition below include a photocurable resin composition containing a photopolymerization initiator, a photocurable thermosetting resin composition, a photocurable resin composition containing a photobase generator, and a photoacid. Photocurable resin composition containing a generator, negative photocurable resin composition, positive photocurable resin composition, alkali-developed photocurable resin composition, solvent-developed photocurable resin composition, etc. The present invention includes, but is not limited to, a photosensitive resin composition, a thermosetting resin composition, a swelling peeling type resin composition, and a dissolution peeling type resin composition. Of these, a photosensitive resin composition is preferable, and a photosensitive resin composition containing an alkali-soluble resin, a photopolymerization initiator, a compound having an ethylenically unsaturated bond, and a thermosetting resin is more preferable.

(Photocurable thermosetting resin composition)
As an example of the photocurable thermosetting resin composition, a resin composition containing an alkali-soluble resin, a photopolymerization initiator, a compound having an ethylenically unsaturated bond, and a thermosetting resin will be described below.

The alkali-soluble resin is a resin containing one or more functional groups of a phenolic hydroxyl group, a thiol group and a carboxyl group and is soluble in an alkaline solution, preferably a compound having two or more phenolic hydroxyl groups, a carboxyl group. Examples thereof include a contained resin, a compound having a phenolic hydroxyl group and a carboxyl group, and a compound having two or more thiol groups. As the alkali-soluble resin, a carboxyl group-containing resin or a phenolic hydroxyl group-containing resin can be used, but a carboxyl group-containing resin is preferable.

The carboxyl group-containing resin is a component that polymerizes or crosslinks and is cured by light irradiation, and can be made alkaline developable by containing a carboxyl group. Further, from the viewpoint of photocurability and development resistance, it is preferable to have an ethylenically unsaturated bond in the molecule in addition to the carboxyl group, but only a carboxyl group-containing resin having no ethylenically unsaturated double bond. May be used. The ethylenically unsaturated bond is preferably derived from acrylic acid or methacrylic acid or a derivative thereof. Among the carboxyl group-containing resins, a carboxyl group-containing resin having a copolymer structure, a carboxyl group-containing resin having a urethane structure, a carboxyl group-containing resin using an epoxy resin as a starting material, and a carboxyl group-containing resin using a phenol compound as a starting material are available. preferable. Specific examples of the carboxyl group-containing resin include compounds (either oligomers or polymers) listed below.

(1) A dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride is reacted with a bifunctional or higher polyfunctional epoxy resin by reacting (meth) acrylic acid with the hydroxyl group existing in the side chain. Carboxyl group-containing photosensitive resin to which Here, the bifunctional or higher polyfunctional epoxy resin is preferably solid.

(2) A carboxyl group obtained by reacting a polyfunctional epoxy resin obtained by epoxidizing the hydroxyl group of a bifunctional epoxy resin with epichlorohydrin with (meth) acrylic acid and adding a dibasic acid anhydride to the generated hydroxyl group. Containing photosensitive resin. Here, the bifunctional epoxy resin is preferably solid.

(3) An epoxy compound having two or more epoxy groups in one molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, and non-hydride such as (meth) acrylic acid. A multi-base such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic acid, etc., with respect to the alcoholic hydroxyl group of the reaction product obtained by reacting with a saturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting an acid anhydride.

(4) Two or more in one molecule of bisphenol A, bisphenol F, bisphenol S, novolak type phenol resin, poly-p-hydroxystyrene, condensate of naphthol and aldehydes, condensate of dihydroxynaphthalene and aldehydes, etc. A reaction obtained by reacting a reaction product obtained by reacting a compound having a phenolic hydroxyl group with an alkylene oxide such as ethylene oxide or propylene oxide with an unsaturated group-containing monocarboxylic acid such as (meth) acrylic acid. A carboxyl group-containing photosensitive resin obtained by reacting a product with a polybasic acid anhydride.

(5) An unsaturated group-containing monocarboxylic acid is reacted with a reaction product obtained by reacting a compound having two or more phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate. , A carboxyl group-containing photosensitive resin obtained by reacting the obtained reaction product with a polybasic acid anhydride.

(6) Aliphatic compounds such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates, and polycarbonate-based polyols, polyether-based polyols, polyester-based polyols, polyolefin-based polyols, acrylic-based polyols, and bisphenol A-based An alkylene oxide adduct diol, a terminal carboxyl group-containing urethane resin obtained by reacting an acid anhydride with the end of a urethane resin obtained by a double addition reaction of a diol compound such as a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group.

(7) Molecules such as hydroxyalkyl (meth) acrylate during the synthesis of a carboxyl group-containing urethane resin by a double addition reaction between a diisocyanate, a carboxyl group-containing dialcohol compound such as dimethylolpropionic acid and dimethylolbutyric acid, and a diol compound. A carboxyl group-containing urethane resin obtained by adding a compound having one hydroxyl group and one or more (meth) acryloyl groups to the terminal (meth) acrylic acid.

(8) During the synthesis of the carboxyl group-containing urethane resin by the double addition reaction of the diisocyanate, the carboxyl group-containing dialcohol compound, and the diol compound, 1 in the molecule such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate. A carboxyl group-containing urethane resin obtained by adding a compound having one isocyanate group and one or more (meth) acryloyl groups to terminal (meth) acrylicization.

(9) Carboxy group-containing photosensitive obtained by copolymerization of an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate, and isobutylene. resin.

(10) A carboxyl group obtained by reacting a polyfunctional oxetane resin as described later with a dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid, and adding a dibasic acid anhydride to the generated primary hydroxyl group. A carboxyl group formed by adding a compound having one epoxy group and one or more (meth) acryloyl groups in one molecule such as glycidyl (meth) acrylate and α-methylglycidyl (meth) acrylate to the containing polyester resin. Containing photosensitive resin.

(11) A carboxyl group-containing photosensitive resin obtained by adding a compound having a cyclic ether group and a (meth) acryloyl group to one of the above-mentioned carboxyl group-containing resins (1) to (10).

Here, (meth) acrylate is a general term for acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions below.

The acid value of the carboxyl group-containing resin is preferably 40 to 150 mgKOH / g. When the acid value of the carboxyl group-containing resin is 40 mgKOH / g or more, alkaline development becomes good. Further, by setting the acid value to 150 mgKOH / g or less, it is possible to easily draw a normal resist pattern. More preferably, it is 50 to 130 mgKOH / g.

The blending amount of the alkali-soluble resin is, for example, 15 to 60% by mass, preferably 20 to 60% by mass, based on the total amount of the resin layer excluding the solvent. The coating film strength can be improved by setting the content to 15% by mass or more, preferably 20% by mass or more. Further, when the content is 60% by mass or less, the viscosity becomes appropriate and the workability is improved. More preferably, it is 30 to 50% by mass.

As the photopolymerization initiator used for photopolymerizing the above-mentioned alkali-soluble resin, known photopolymerization initiators can be used, and among them, an oxime ester-based photopolymerization initiator having an oxime ester group, α-amino. Acetphenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, and titanosen-based photopolymerization initiators are preferable. One type of photopolymerization initiator may be used alone, or two or more types may be used in combination.
The blending amount of the photopolymerization initiator is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the alkali-soluble resin. This is because, within this range, the photocurability on copper is sufficient, the curability of the coating film is good, the coating film characteristics such as chemical resistance are improved, and the deep curability is also improved. .. More preferably, it is 0.5 to 15 parts by mass with respect to 100 parts by mass of the alkali-soluble resin.

When the oxime ester-based photopolymerization initiator is used, the blending amount is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the alkali-soluble resin. By setting the amount to 0.01 parts by mass or more, the photocurability on copper becomes more reliable, and the coating film characteristics such as chemical resistance are improved. Further, when the amount is 5 parts by mass or less, light absorption on the surface of the coating film is suppressed, and the curability of the deep part tends to be improved. More preferably, it is 0.1 to 3 parts by mass with respect to 100 parts by mass of the alkali-soluble resin.

When the α-aminoacetophenone-based photopolymerization initiator or the acylphosphine oxide-based photopolymerization initiator is used, the blending amount thereof is preferably 0.01 to 15 parts by mass with respect to 100 parts by mass of the alkali-soluble resin. .. By setting the amount to 0.01 parts by mass or more, the photocurability on copper becomes more reliable, and the coating film characteristics such as chemical resistance are improved. Further, by setting the amount to 15 parts by mass or less, a sufficient effect of reducing outgas can be obtained, light absorption on the surface of the cured film is suppressed, and the curability of the deep portion is also improved. More preferably, it is 0.5 to 10 parts by mass with respect to 100 parts by mass of the alkali-soluble resin.

A photoinitiator or sensitizer may be used in combination with the photopolymerization initiator described above. Examples of the photoinitiator aid or sensitizer include benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds, and xanthone compounds. Although these compounds may be used as a photopolymerization initiator, they are preferably used in combination with a photopolymerization initiator. In addition, one type of photoinitiator aid or sensitizer may be used alone, or two or more types may be used in combination.

The photocurable thermosetting resin composition contains a thermosetting resin for the purpose of improving properties such as heat resistance and insulation reliability. Examples of the thermosetting resin include known and commonly used thermosetting compounds such as isocyanate compounds, blocked isocyanate compounds, amino resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, polyfunctional epoxy compounds, polyfunctional oxetane compounds, and episulfide resins. Sex resin can be used. Among these, the preferred thermosetting resin is a thermosetting resin having at least one of a plurality of cyclic ether groups and cyclic thioether groups (hereinafter, abbreviated as cyclic (thio) ether groups) in one molecule. Many of these thermosetting resins having a cyclic (thio) ether group are commercially available, and various properties can be imparted depending on the structure thereof. It is preferable that these thermosetting resins include those having a softening point or a melting point of 100 ° C. or lower. When an epoxy resin having a softening point or a melting point of 100 ° C. or less is used, the time required for the resin layer viscosity to decrease due to heating during laminating is shortened, the circuit followability of the resin layer is improved, and the resin layer is flattened. It is preferable because it is easy to improve heat resistance. These thermosetting resins may be used alone or in combination with a thermosetting resin having a softening point or a melting point of more than 100 ° C.

The amount of the thermosetting resin having a plurality of cyclic (thio) ether groups in the molecule is preferably 0.3 to 2.5 equivalents, more preferably 0.3 to 2.5 equivalents, relative to 1 equivalent of the alkali-soluble groups of the alkali-soluble resin. It is in the range of 0.5 to 2.0 equivalents. By setting the blending amount of the thermosetting resin having a plurality of cyclic (thio) ether groups in the molecule to 0.3 equivalent or more, no alkali-soluble group remains in the cured film, and heat resistance, alkali resistance, and electrical insulation are obtained. Gender is improved. Further, when the amount is 2.5 equivalents or less, low molecular weight cyclic (thio) ether groups do not remain in the dry coating film, and the strength of the cured film is improved.

When a thermosetting resin having a plurality of cyclic (thio) ether groups in the molecule is used, it is preferable to contain a thermosetting catalyst. Examples of such a thermocuring catalyst include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole. , 1- (2-Cyanoethyl) -2-ethyl-4-methylimidazole and other imidazole derivatives; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N Examples thereof include amine compounds such as -dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. In addition, guanamine, acetguanamine, 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, preferably as these adhesion-imparting agents. A compound that also functions is used in combination with a thermocuring catalyst.

The blending amount of the thermosetting catalyst is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass with respect to 100 parts by mass of the thermosetting resin having a plurality of cyclic (thio) ether groups in the molecule. It is a mass part.

In addition to the above-mentioned alkali-soluble resin, photopolymerization initiator, and thermosetting resin, the photocurable thermosetting resin composition has one or more ethylenically unsaturated bonds in the molecule as a photosensitive monomer. The compound to have may be contained. The photosensitive monomer assists the photocuring of the alkali-soluble resin by irradiation with active energy rays.

Examples of the compound used as the compound having an ethylenically unsaturated bond include commonly known polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate, and epoxy (meth) acrylate. And so on. Specifically, hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol and propylene glycol; N, N-dimethylacrylamide. , N-methylol acrylamide, acrylamides such as N, N-dimethylaminopropyl acrylamide; aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate, N, N-dimethylaminopropyl acrylate; Polyhydric alcohols such as pentaerythritol, dipentaerythritol, tris-hydroxyethyl isocyanurate or polyhydric acrylates such as ethylene oxide adducts, propylene oxide adducts, or ε-caprolactone adducts; phenoxyacrylate, bisphenol A di. Polyvalent acrylates such as acrylates and ethylene oxide adducts or propylene oxide adducts of these phenols; glycidyl ethers such as glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylolpropan triglycidyl ether, triglycidyl isocyanurate. Polyvalent acrylates; Not limited to the above, acrylates and melamine acrylates obtained by directly acrylated polyols such as polyether polyols, polycarbonate diols, hydroxyl group-terminated polybutadienes, polyester polyols, or urethane acrylates via diisocyanates, and the acrylates. It can be appropriately selected and used from at least one of each methacrylate corresponding to the above.

An epoxy acrylate resin obtained by reacting a polyfunctional epoxy resin such as cresol novolac type epoxy resin with acrylic acid, and a hydroxy acrylate such as pentaerythritol triacrylate and a diisocyanate half urethane such as isophorone diisocyanate on the hydroxyl group of the epoxy acrylate resin. An epoxy urethane acrylate compound or the like obtained by reacting the compound may be used as the photosensitive monomer. Such an epoxy acrylate-based resin can improve the photocurability without lowering the dryness to the touch.

The blending amount of the compound having an ethylenically unsaturated bond is preferably 5 to 100 parts by mass, more preferably 5 to 70 parts by mass with respect to 100 parts by mass of the alkali-soluble resin. By setting the blending amount of the compound having an ethylenically unsaturated bond to 5 parts by mass or more, the photocurability of the photocurable thermosetting resin composition is improved. Further, the hardness of the coating film can be improved by setting the blending amount to 100 parts by mass or less.

In addition to the above-mentioned components, the photocurable thermosetting resin composition may contain other components such as fillers, colorants, elastomers, and thermoplastic resins. Hereinafter, these components will also be described.

It is preferable to add a filler to the photocurable thermosetting resin composition in order to increase the physical strength of the obtained cured product and to adjust the viscosity. As the filler, known and commonly used inorganic or organic fillers can be used, but barium sulfate, spherical silica, titanium oxide, Neuburg diatomaceous earth particles, and talc are particularly preferably used. Further, aluminum hydroxide, magnesium hydroxide, boehmite and the like can also be used for the purpose of imparting flame retardancy. These can be used alone or in combination of two or more.
The average particle size (D50) of the inorganic filler is preferably 25 μm or less, more preferably 10 μm or less, and further preferably 3 μm or less. Here, D50 is a particle size at a volume accumulation of 50% obtained by using a laser diffraction scattering type particle size distribution measurement method based on the Mie scattering theory. More specifically, it can be measured by creating a particle size distribution of fine particles on a volume basis by a laser diffraction / scattering type particle size distribution measuring device and using the median diameter as the average particle size. As the measurement sample, those in which fine particles are dispersed in water by ultrasonic waves can be preferably used. As the laser diffraction type particle size distribution measuring device, LA-500 manufactured by HORIBA, Ltd. or the like can be used.
Examples of the shape of the filler include spherical shape, needle shape, plate shape, scale shape, hollow shape, amorphous shape, hexagonal shape, cubic shape, flaky shape and the like.

The amount of the filler added is preferably 500 parts by mass or less, more preferably 0.1 to 350 parts by mass, based on 100 parts by mass of the alkali-soluble resin. When the amount of the filler added is 500 parts by mass or less, the viscosity of the photocurable thermosetting resin composition does not become too high, the printability is good, and the cured product is less likely to become brittle.

The photocurable thermosetting resin composition may contain a colorant. As the colorant, known colorants such as red, blue, green, yellow, black, and white can be used, and any of pigments, dyes, and pigments may be used. However, it is preferable not to contain halogen from the viewpoint of reducing the environmental load and affecting the human body.

The amount of the colorant added is not particularly limited, but is preferably 10 parts by mass or less, particularly preferably 0.1 to 7 parts by mass, with respect to 100 parts by mass of the alkali-soluble resin.

In addition, an elastomer can be added to the photocurable thermosetting resin composition for the purpose of imparting flexibility to the obtained cured product, improving the brittleness of the cured product, and the like. Examples of the elastomer include polyester-based elastomers, polyurethane-based elastomers, polyester-urethane-based elastomers, polyamide-based elastomers, polyesteramide-based elastomers, acrylic-based elastomers, and olefin-based elastomers. Further, a resin obtained by modifying a part or all of the epoxy groups of the epoxy resin having various skeletons with both-terminal carboxylic acid-modified butadiene-acrylonitrile rubber can also be used. Further, an epoxy-containing polybutadiene-based elastomer, an acrylic-containing polybutadiene-based elastomer, a hydroxyl group-containing polybutadiene-based elastomer, a hydroxyl group-containing isoprene-based elastomer, and the like can also be used. The elastomer may be used alone or as a mixture of two or more.

The amount of the elastomer added is preferably 50 parts by mass or less, more preferably 1 to 30 parts by mass, and particularly preferably 5 to 30 parts by mass with respect to 100 parts by mass of the alkali-soluble resin. When the amount of the elastomer added is 50 parts by mass or less, the alkali developability of the photocurable thermosetting resin composition is good, and the developable pot life is unlikely to be shortened.

Further, the photocurable thermosetting resin composition can further contain components such as a block copolymer, an adhesion accelerator, an antioxidant, and an ultraviolet absorber, if necessary. As these, those known in the field of electronic materials can be used. In addition, at least one of known and commonly used thickeners such as fine silica, hydrotalcite, organic bentonite, and montmorillonite, silicone-based, fluorine-based, and polymer-based defoaming agents and leveling agents, imidazole, and thiazole. At least one of known and commonly used additives such as a silane coupling agent such as a system and a triazole system, a rust preventive, and a fluorescent whitening agent can be blended.

The organic solvent that can be used is not particularly limited, and examples thereof include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents and the like. be able to. More specifically, ketones such as methyl ethyl ketone, cyclohexanone, methyl butyl ketone, methyl isobutyl ketone and methyl ethyl ketone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol and methyl. Glycol ethers such as carbitol, butyl carbitol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether. Classes; esters such as ethyl acetate, butyl acetate, isobutyl acetate, ethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate; ethanol, propanol, Alcohols such as 2-methoxypropanol, n-butanol, isobutyl alcohol, isopentyl alcohol, ethylene glycol, propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, solvent naphtha, etc. In addition to the petroleum-based solvent of N, N-dimethylformamide (DMF), tetrachloroethylene, televisionne oil and the like. In addition, Maruzen Petrochemical Co., Ltd. Swazol 1000, Swazol 1500, Standard Oil Osaka Sales Office Co., Ltd. Solbesso 100, Solvesso 150, Sankyo Chemical Co., Ltd. Solvent # 100, Solvent # 150, Shell Chemicals Japan Co., Ltd. , Idemitsu Kosan Co., Ltd. Ipsol No. 100, Ipsol No. 150 and other organic solvents may be used. Such an organic solvent may be used alone or as a mixture of two or more.

As a method for producing a printed wiring board using a laminated film having a resin layer made of a photocurable thermosetting resin composition, a conventionally known method may be used. For example, when a laminated film in which the (A) resin layer is sandwiched between the (B) film and the (C) film as shown in FIG. 2 is used, the printed wiring board can be manufactured by the following method. The (C) film is peeled off from the laminated film to expose the (A) resin layer, and the (A) resin layer of the laminated film is heated under heating conditions using a vacuum laminator or the like on a substrate on which a circuit pattern is formed. Vacuum laminate with (A) and pattern exposure is performed on the resin layer (A). The film (B) may be peeled off either after laminating or after exposure. After that, a patterned resin layer is formed on the substrate by performing alkaline development, and the patterned resin layer is cured by light irradiation or heat to form a cured film to manufacture a printed wiring board. can do.

(Thermosetting resin composition)
As an example of the thermosetting resin composition, a resin composition containing a thermosetting resin will be described below.

A thermosetting resin is a resin having a functional group capable of a curing reaction by heat. The thermosetting resin is not particularly limited, and an epoxy compound, a polyfunctional oxetane compound, a compound having two or more thioether groups in the molecule, that is, an episulfide resin and the like can be used.

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

Examples of the epoxy compound include 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, and cresol novolac type. Epoxy resin, bisphenol A novolak type epoxy resin, biphenyl type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, triphenylmethane type epoxy resin, alicyclic epoxy resin, aliphatic chain Epoxy resins, phosphorus-containing epoxy resins, anthracene-type epoxy resins, norbornene-type epoxy resins, adamantan-type epoxy resins, fluorene-type epoxy resins, aminophenol-type epoxy resins, aminocresol-type epoxy resins, alkylphenol-type epoxy resins and the like are used. These epoxy resins may be used alone or in combination of two or more.

The epoxy compound may be any of a solid epoxy resin, a semi-solid epoxy resin, and a liquid epoxy resin. In the present specification, the solid epoxy resin refers to an epoxy resin that is solid at 40 ° C., and the semi-solid epoxy resin refers to an epoxy resin that is solid at 20 ° C. and liquid at 40 ° C., and is a liquid epoxy resin. Refers to an epoxy resin that is liquid at 20 ° C. Judgment of liquidity is carried out in accordance with the "Liquid confirmation method" of Attachment 2 of the Ministerial Ordinance on Dangerous Goods Testing and Properties (Ministry of Home Affairs Ordinance No. 1 of 1989).

As the thermosetting resin, one type may be used alone or two or more types may be used in combination. The blending amount of the thermosetting resin is preferably 10 to 50% by mass, more preferably 10 to 40% by mass, still more preferably 10 to 35% by mass, based on the total amount of the resin layer excluding the solvent. preferable. Further, when the liquid epoxy resin is blended, the blending amount of the liquid epoxy resin is 0 to 45 mass per total mass of the thermosetting resin because the glass transition temperature (Tg) of the cured product and the crack resistance are better. %, More preferably 0 to 30% by mass, and particularly preferably 0 to 5% by mass.

A filler can be added to the thermosetting resin composition, if necessary, in order to increase the physical strength of the obtained cured product. The filler is not particularly limited, and examples thereof include the filler exemplified in the photocurable thermosetting resin composition. The filler may be used alone or as a mixture of two or more.

The organic solvent that can be used is not particularly limited, and examples thereof include the organic solvent exemplified in the photocurable thermosetting resin composition. The organic solvent may be used alone or as a mixture of two or more.

The thermosetting resin composition can contain a curing agent. Examples of the curing agent include phenol resins, polycarboxylic acids and their acid anhydrides, cyanate ester resins, active ester resins, maleimide compounds, alicyclic olefin polymers and the like. As the curing agent, one type may be used alone or two or more types may be used in combination.

In the above curing agent, the ratio of a functional group capable of a thermosetting reaction such as an epoxy group of a thermosetting resin to a functional group in the curing agent that reacts with the functional group is the functional group / thermosetting reaction of the curing agent. It is preferable to blend in a ratio such that the functional groups (equivalent ratio) that can be used are 0.2 to 2. By setting the functional group (equivalent ratio) capable of the functional group / thermosetting reaction of the curing agent within the above range, roughening of the film surface in the desmear step can be prevented. More preferably, the functional group of the curing agent / the functional group capable of the thermosetting reaction (equivalent ratio) = 0.2 to 1.5, and more preferably the functional group of the curing agent / the functional group capable of the thermosetting reaction (equivalent ratio). Equivalent ratio) = 0.3 to 1.2.

The thermosetting resin composition can further contain a thermoplastic resin in order to improve the mechanical strength of the obtained cured film. The thermoplastic resin is preferably soluble in a solvent. When it is soluble in a solvent, the flexibility of the dry film is improved, and the generation of cracks and powder falling can be suppressed. As the thermoplastic resin, various acid anhydrides or acid chlorides are used for the thermoplastic polyhydroxypolyether resin, the phenoxy resin which is a condensate of epichlorohydrin and various bifunctional phenol compounds, or the hydroxyl group of the hydroxyether portion existing in the skeleton thereof. Examples thereof include a phenoxy resin, a polyvinyl acetal resin, a polyamide resin, a polyamideimide resin, and a block copolymer that have been esterified. The thermoplastic resin may be used alone or in combination of two or more.

The blending amount of the thermoplastic resin is preferably 0.5 to 20% by mass, preferably 0.5 to 10% by mass, based on the total amount of the resin layer excluding the solvent. If the blending amount of the thermoplastic resin is out of the above range, it becomes difficult to obtain a uniform roughened surface state.

Further, the thermosetting resin composition can contain rubber-like particles, if necessary. Examples of such rubber-like particles include polybutadiene rubber, polyisopropylene rubber, urethane-modified polybutadiene rubber, epoxy-modified polybutadiene rubber, acrylonitrile-modified polybutadiene rubber, carboxyl group-modified polybutadiene rubber, carboxyl group-modified or hydroxyl-modified acrylonitrile butadiene rubber, and Examples thereof include crosslinked rubber particles and core-shell type rubber particles, and one type can be used alone or in combination of two or more types. These rubber-like particles are added to improve the flexibility of the obtained cured film, improve crack resistance, enable surface roughness treatment with an oxidizing agent, and improve the adhesion strength with copper foil and the like. Will be done.

The average particle size of the rubber-like particles is preferably in the range of 0.005 to 1 μm, more preferably in the range of 0.2 to 1 μm. The average particle size of the rubber-like particles in the present invention can be measured by using a dynamic light scattering method. For example, the rubber-like particles are uniformly dispersed in an appropriate organic solvent by ultrasonic waves or the like, and the particle size distribution of the rubber-like particles is prepared on the basis of mass using FPRA-1000 (manufactured by Otsuka Electronics Co., Ltd.), and the median diameter thereof is determined. It can be measured by setting the average particle size.

The blending amount of the rubber-like particles is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass, based on the total amount of the resin layer excluding the solvent. When it is 0.5% by mass or more, crack resistance can be obtained and the adhesion strength with the conductor pattern or the like can be improved. When it is 10% by mass or less, the coefficient of thermal expansion (CTE) decreases, the glass transition temperature (Tg) increases, and the curing characteristics are improved.

The thermosetting resin composition can contain a curing accelerator. The curing accelerator accelerates the thermosetting reaction, and is used to further improve properties such as adhesion, chemical resistance, and heat resistance. Specific examples of such a curing accelerator include imidazole and its derivatives; guanamines such as acetoguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulphon, disyandiamide, urea, urea derivatives, etc. Polyamines such as melamine, polybasic hydrazide; these organolates and / or epoxy adducts; amine complexes of boron trifluoride; ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4- Triazine derivatives such as diamino-6-xylyl-S-triazine; trimethylamine, triethanolamine, N, N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholin, hexa (N-methyl) melamine, Amines such as 2,4,6-tris (dimethylaminophenol), tetramethylguanidine, m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, alkylphenol novolac; tributylphosphine, triphenylphosphine , Organic phosphines such as tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide, hexadecyltributylphosphonium chloride; Tertiary ammonium salts; the polybasic acid anhydrides; photocationic polymerization catalysts such as diphenyliodonium tetrafluoroboroate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyrylium hexafluorophosphate; styrene- Maleic anhydride resin; isomolar reactants of phenylisocyanate and dimethylamine, equimolar reactants of organic polyisocyanate such as tolylene diisocyanate and isophorone diisocyanate and dimethylamine, and conventionally known curing accelerators such as metal catalysts can be mentioned. .. Among the curing accelerators, phosphonium salts are preferable because BHAST resistance can be obtained.

As the curing accelerator, one type may be used alone or two or more types may be mixed. The use of a curing accelerator is not essential, but when it is particularly desired to accelerate curing, it can be preferably used in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the thermosetting resin. In the case of a metal catalyst, 10 to 550 ppm is preferable in terms of metal with respect to 100 parts by mass of the thermosetting resin, and 25 to 200 ppm is preferable.

If necessary, the thermosetting resin composition further comprises a conventionally known colorant such as phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, and asbestos. Adhesion of conventionally known thickeners such as olben, benton, and fine powder silica, defoaming agents such as silicone-based, fluorine-based, and polymer-based and / or leveling agents, thiazole-based, triazole-based, and silane coupling agents. Conventionally known additives such as an imparting agent, a flame retardant, a titanate type, and an aluminum type can be used.

As a method for producing a printed wiring board using a laminated film having a resin layer made of a thermosetting resin composition, a conventionally known method may be used. For example, when a laminated film in which the (A) resin layer is sandwiched between the (B) film and the (C) film as shown in FIG. 2 is used, the printed wiring board can be manufactured by the following method. The film (C) is peeled from the laminated film, laminated on a circuit board on which a circuit pattern is formed using a vacuum laminator or the like under heating conditions, and then thermosetting. The thermosetting may be cured in an oven or may be cured by a hot plate press. When laminating or hot plate pressing a wiring board on which a circuit is formed and a laminated film of the present invention, a copper foil or a wiring board on which a circuit is formed can be laminated at the same time. A printed wiring board can be manufactured by forming a pattern or a via hole by laser irradiation or a drill at a position corresponding to a predetermined position on a substrate on which a circuit pattern is formed to expose the circuit wiring. At this time, if there is a residual component (smear) that cannot be completely removed on the pattern or the circuit wiring in the via hole, the desmear treatment is performed. The film (B) may be peeled off either after laminating, after thermosetting, after laser processing, or after desmear treatment.

(Composition containing photobase generator)
As an example of the photobase generator-containing composition, a composition containing an alkali-developable resin, a thermosetting component, and a photobase generator will be described below.

The alkali-developable resin is a resin containing one or more functional groups of a phenolic hydroxyl group, a thiol group and a carboxyl group and can be developed with an alkaline solution, preferably a compound having two or more phenolic hydroxyl groups, carboxyl. Examples thereof include a group-containing resin, a compound having a phenolic hydroxyl group and a carboxyl group, and a compound having two or more thiol groups.

As the carboxyl group-containing resin, a known resin containing a carboxyl group can be used. The presence of the carboxyl group allows the resin composition to be alkaline developable. Further, in addition to the carboxyl group, a compound having an ethylenically unsaturated bond in the molecule may be used, but in the present invention, the carboxyl group-containing resin is a carboxyl group having no ethylenically unsaturated double bond. It is preferable to use only the contained resin.

Specific examples of the carboxyl group-containing resin include compounds (1) to (11) listed below as the carboxyl group-containing resin contained in the photocurable thermosetting resin composition, as well as compounds listed below. It may be either an oligomer or a polymer).

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

(13) 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 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.

(14) During the synthesis of the resin according to (12) or (13), a compound having one hydroxyl group and one or more (meth) acryloyl groups in a molecule such as hydroxyalkyl (meth) acrylate was added to the terminal (14). Meta) Acryloylated carboxyl group-containing urethane resin.

(15) During the synthesis of the resin according to (12) or (13), one isocyanate group and one or more (meth) acryloyl groups are added to the molecule, such as an isophorone diisocyanate and pentaerythritol triacrylate equimolar reaction product. A carboxyl group-containing urethane resin that is terminally (meth) acrylicized by adding the compound to be possessed.

(16) Containing a carboxyl group obtained by reacting a polyfunctional epoxy resin with a saturated monocarboxylic acid and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to a hydroxyl group existing in a side chain. resin. Here, the polyfunctional epoxy resin is preferably solid.

(17) A carboxyl group-containing polyester resin obtained by reacting a polyfunctional oxetane resin with a dicarboxylic acid and adding a dibasic acid anhydride to the generated primary hydroxyl group.

(18) Carboxyl group-containing resin obtained by reacting a polybasic acid anhydride with 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. ..

(19) A saturated monocarboxylic acid is reacted with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide, and the obtained reaction product is abundant. A carboxyl group-containing resin obtained by reacting a basic acid anhydride.

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

(21) A carboxyl group obtained by reacting a polybasic acid anhydride with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate. Containing resin.

(22) 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 a saturated monocarboxylic acid. The reaction product is reacted with an acid, and a polybasic acid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and adipic acid is reacted with the alcoholic hydroxyl group of the obtained reaction product. Carboxylic group-containing resin obtained by

(23) An epoxy compound having a plurality of epoxy groups in one molecule is reacted with at least one alcoholic hydroxyl group in one molecule such as p-hydroxyphenethyl alcohol and a compound having one phenolic hydroxyl group. A carboxyl group obtained by reacting the alcoholic hydroxyl group of the obtained reaction product with a polybasic acid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, or adipic acid. Containing resin.

(24) In addition to the resin according to any one of (12) to (23) above, one epoxy group and one or more (meth) acryloyl in the molecule such as glycidyl (meth) acrylate and α-methylglycidyl (meth) acrylate. A carboxyl group-containing resin obtained by adding a compound having a group.

Since the alkaline developable resin as described above has a large number of carboxyl groups, hirodoxy groups, etc. in the side chain of the backbone polymer, it can be developed with an alkaline aqueous solution.
The hydroxyl group equivalent or carboxyl group equivalent of the alkali-developable resin is 80 to 900 g / eq. Is more preferable, and more preferably 100 to 700 g / eq. Is. The hydroxyl group equivalent or the carboxyl group equivalent is 900 g / eq. In the following cases, the adhesion of the pattern layer is obtained, and alkaline development becomes easy. On the other hand, the hydroxyl group equivalent or the carboxyl group equivalent is 80 g / eq. In the above case, dissolution of the light-irradiated portion by the developing solution is suppressed, the line is not thinned more than necessary, and a normal resist pattern can be easily drawn, which is preferable. Further, when the carboxyl group equivalent or the phenol group equivalent is large, development is possible even when the content of the alkaline developable resin is small, which is preferable.

The acid value of the alkaline developable resin is preferably 40 to 150 mgKOH / g. When the acid value of the alkaline developable resin is 40 mgKOH / g or more, the alkaline development becomes good. Further, by setting the acid value to 150 mgKOH / g or less, it is possible to easily draw a normal resist pattern. More preferably, it is 50 to 130 mgKOH / g.

The blending amount of the alkaline developable resin is preferably 20 to 60% by mass based on the total amount of the resin layer of the dry film excluding the solvent. The coating film strength can be improved by setting the content to 20% by mass or more. Further, when the content is 60% by mass or less, the viscosity becomes appropriate and the coatability is improved. More preferably, it is 30 to 50% by mass.

The heat-reactive compound is a resin having a functional group capable of a curing reaction by heat. Examples thereof include epoxy resins and polyfunctional oxetane compounds.

The epoxy resin is a resin having an epoxy group, and any known epoxy resin can be used. Examples thereof include a bifunctional epoxy resin having two epoxy groups in the molecule, a polyfunctional epoxy resin having many epoxy groups in the molecule, and the like. It may be a hydrogenated bifunctional epoxy compound.

The epoxy resin preferably has an epoxy equivalent of 90 or more. When the epoxy equivalent is 90 or more, the warp of the cured film is suppressed, and the developability is excellent even when the cured film is left in high humidity for a long time.

As for the blending amount of the heat-reactive compound, the equivalent ratio with the alkali-developable resin (heat-reactive group: alkali-developable group) is preferably 1: 0.1 to 1:10, preferably 1: 0. .2 to 1: 8 is more preferable. When it is within the range of such a compounding ratio, the development becomes good.

The photobase generator is one or more kinds that can function as a catalyst for the addition reaction of the above-mentioned heat-reactive compound by changing the molecular structure by irradiation with light such as ultraviolet rays or visible light or by cleaving the molecule. It is a compound that produces a basic substance. Examples of the basic substance include secondary amines and tertiary amines.

Examples of the photobase generator include α-aminoacetophenone compound, oxime ester compound, acyloxyimino group, N-formylated aromatic amino group, N-acylated aromatic amino group, nitrobenzyl carbamate group, and alcoholic benzyl carbamate. Examples thereof include compounds having a substituent such as a group.

The above photobase generator may be used alone or in combination of two or more. The blending amount of the photobase generator in the photobase generator-containing composition is preferably 1 to 50 parts by mass, and more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the heat-reactive compound. When it is 1 part by mass or more, it is preferable because development becomes easy.

A filler can be added to the photobase generator-containing composition, if necessary, in order to increase the physical strength of the obtained cured product. The filler is not particularly limited, and examples thereof include the filler exemplified in the photocurable thermosetting resin composition. The filler may be used alone or as a mixture of two or more.

The organic solvent that can be used is not particularly limited, and examples thereof include the organic solvent exemplified in the photocurable thermosetting resin composition. The organic solvent may be used alone or as a mixture of two or more.

If necessary, the photobase generator-containing composition may further contain components such as a mercapto compound, an adhesion accelerator, an antioxidant, and an ultraviolet absorber. As these, those known in the field of electronic materials can be used.
In addition, the above-mentioned photobase generator-containing composition includes known and commonly used thickeners such as fine powder silica, hydrotalcite, organic bentonite, and montmorillonite, and defoaming agents such as silicone-based, fluorine-based, and polymer-based. Alternatively, known and commonly used additives such as leveling agents, silane coupling agents, rust preventives and the like can be blended.

As a method for producing a printed wiring board using a laminated film having a resin layer made of a photobase generator-containing composition, a conventionally known method may be used. For example, when a laminated film in which the (A) resin layer is sandwiched between the (B) film and the (C) film as shown in FIG. 2 is used, the printed wiring board can be manufactured by the following method. The (C) film is peeled off from the laminated film to expose the (A) resin layer, and the (A) resin layer of the laminated film is heated under heating conditions on the substrate on which the circuit pattern is formed by using a vacuum laminator or the like. Vacuum laminate. After that, the photobase generator contained in the photobase generator-containing resin composition is activated by negative-type patterned light irradiation to cure the light-irradiated portion, and the unirradiated portion is removed by alkaline development to remove the negative. A pattern layer of the mold can be formed. The film (B) may be peeled off either after laminating or after exposure. Further, it is preferable to heat the resin layer (A) after light irradiation and before development. As a result, the resin layer (A) can be sufficiently cured to obtain a pattern layer having further excellent curing characteristics. The heating after light irradiation and before development is preferably at a temperature at which the unirradiated portion is not thermoset. Further, it is preferable to perform thermosetting (post-cure) after development. After the development, the photobase generator that remains unactivated during the light irradiation may be activated by irradiating with ultraviolet rays, and then thermosetting (post-cure) may be performed.

(Positive Photosensitive Thermosetting Resin Composition)
As an example of the positive photosensitive thermosetting resin composition, a resin composition containing a compound that generates a carboxyl group by light irradiation will be described below.

Among the compounds that generate a carboxyl group by light irradiation, it is preferable to use a naphthoquinone diazide compound. The naphthoquinone diazide compound has been conventionally used in a system in which alkali solubility such as a carboxyl group is suppressed by forming a complex with a carboxyl group or a phenolic hydroxyl group, and the complex is dissociated by subsequent light irradiation to express alkali solubility. ing. In this case, if the naphthoquinone diazide compound remains in the film, the complex may be dissociated by light irradiation and become soluble. Therefore, in the semiconductor field or the like, the remaining naphthoquinone diazide compound is finally blown off at a high temperature. It was removed by that. However, in the field of printed wiring boards, naphthoquinonediazide compounds have not been practically used because such high temperatures cannot be applied and they cannot be used as a permanent film from the viewpoint of stability. In the present invention, when a naphthoquinone diazide compound is used as a compound that generates a carboxyl group by light irradiation, the naphthoquinone diazide compound remaining in the unexposed portion is incorporated into the crosslinked structure and stabilized during the thermosetting reaction. The film toughness, that is, the bending resistance and the electrical characteristics can be improved without causing the problem of removal as in the conventional case. In particular, by using a naphthoquinone diazide compound as a compound that generates a carboxyl group by light irradiation in combination with a polyamide-imide resin and a thermosetting component, flexibility is effective while ensuring good developability and resolution. It can be improved to the above, which is preferable.

Specific examples of the naphthoquinone diazide compound include a naphthoquinone diazide adduct of tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene (for example, TS533, TS567, TS583, TS593 manufactured by Sanpo Chemical Laboratory Co., Ltd.). ), A naphthoquinone diazide adduct of tetrahydroxybenzophenone (for example, BS550, BS570, BS599 manufactured by Sanpo Chemical Laboratory Co., Ltd.) and the like can be used.

A filler can be added to the positive photosensitive thermosetting resin composition, if necessary, in order to increase the physical strength of the obtained cured product. The filler is not particularly limited, and examples thereof include the filler exemplified in the photocurable thermosetting resin composition. The filler may be used alone or as a mixture of two or more.

Specific examples of the alkali-developable resin contained in the positive photosensitive thermosetting resin composition include the carboxyl group-containing resin exemplified in the photocurable thermosetting resin composition and the photobase generator-containing composition. Examples thereof include an alkali-developable resin exemplified by the material.

The positive photosensitive thermosetting resin composition may contain a thermosetting component for the purpose of improving properties such as heat resistance and insulation reliability. Known and commonly used thermosetting components include isocyanate compounds, blocked isocyanate compounds, amino resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, polyfunctional epoxy compounds, polyfunctional oxetane compounds, and episulfide resins. Sex resin can be used. Among these, a preferable thermosetting component is a thermosetting component having a plurality of cyclic ether groups and / or cyclic thioether groups (hereinafter, abbreviated as cyclic (thio) ether groups) in one molecule. Many of these thermosetting components having a cyclic (thio) ether group are commercially available, and various properties can be imparted depending on the structure thereof.

The blending amount of the thermosetting component having a plurality of cyclic (thio) ether groups in the molecule is preferably 0.3 to 2.5 equivalents, more preferably 0.3 to 2.5 equivalents, based on 1 equivalent of the carboxyl group of the carboxyl group-containing photosensitive resin. Is in the range of 0.5 to 2.0 equivalents. By setting the blending amount of the thermosetting component having a plurality of cyclic (thio) ether groups in the molecule to 0.3 equivalent or more, no carboxyl group remains in the cured film, and heat resistance, alkali resistance, and electrical insulation are provided. Etc. are improved. Further, when the amount is 2.5 equivalents or less, low molecular weight cyclic (thio) ether groups do not remain in the dry coating film, and the strength of the cured film is improved.

The organic solvent that can be used is not particularly limited, and examples thereof include the organic solvent exemplified in the photocurable thermosetting resin composition. The organic solvent may be used alone or as a mixture of two or more.

The positive photosensitive thermosetting resin composition may contain other components such as block copolymers, fillers, colorants, elastomers, and thermoplastic resins in addition to the above-mentioned components. Further, the positive photosensitive thermosetting resin composition can be further blended with components such as an adhesion accelerator, an antioxidant, and an ultraviolet absorber, if necessary. As these, those known in the field of electronic materials can be used. In addition, at least one of known and commonly used thickeners such as fine silica, hydrotalcite, organic bentonite, and montmorillonite, silicone-based, fluorine-based, and polymer-based defoaming agents and leveling agents, imidazole, and thiazole. At least one of known and commonly used additives such as a silane coupling agent such as a system and a triazole system, a rust preventive, and a fluorescent whitening agent can be blended.

As a method for producing a printed wiring board using a laminated film having a resin layer made of a positive photosensitive thermosetting resin composition, a conventionally known method may be used. For example, when a laminated film in which the (A) resin layer is sandwiched between the (B) film and the (C) film as shown in FIG. 2 is used, the printed wiring board can be manufactured by the following method. The (C) film is peeled off from the laminated film, the (A) resin layer is exposed, and the (A) resin layer of the laminated film is evacuated under heating conditions on a substrate on which a circuit pattern is formed using a vacuum laminator or the like. Laminate. After that, the resin layer (A) is irradiated with light in a positive pattern, the resin layer is alkaline-developed, and the light-irradiated portion is removed to form the positive pattern layer. The film (B) may be peeled off either after laminating or after exposure. Further, after development, the resin layer is heat-cured (post-cured) and the unirradiated portion is cured to manufacture a printed wiring board. In the positive photosensitive thermosetting resin composition, the composition is changed to a composition soluble in an alkaline developer by the acid generated by light irradiation, so that a positive pattern can be formed by alkaline development.

[(B) Film]
In the laminated film of the present invention, the film (B) has a 5% elongation load per unit width at 80 ° C. of more than 90 g / mm and 500 g / mm or less. When laminating a laminated film having a resin layer sandwiched between a support film and a protective film, in many cases, the protective film is peeled off and the surface of the resin layer on the side in contact with the protective film is wired. Laminated in contact with the substrate. However, in some cases, the support film is peeled off and laminated so that the surface of the resin layer on the side in contact with the support film comes into contact with the wiring board. In the present invention, since the surface of the resin layer (A) opposite to the film (B) may be laminated on the wiring board so as to be in contact with the wiring board, the film (B) is per unit width at 80 ° C. As long as the film has a 5% elongation load of more than 90 g / mm and 500 g / mm or less, it may be either a support film or a protective film. Preferably, the (B) film is a support film.

The support film has a role of supporting the resin layer of the laminated film, and is a film to which the resin composition is applied when the resin layer is formed. Examples of the support film include polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyimide films, polyamideimide films, polyethylene films, polytetrafluoroethylene films, polypropylene films, and films made of thermoplastic resins such as polystyrene films. Surface-treated paper or the like can be used. Among these, a polyester film can be preferably used from the viewpoints of heat resistance, mechanical strength, handleability and the like. The thickness of the support film is not particularly limited, but is appropriately selected in the range of approximately 10 to 150 μm according to the application. The surface of the support film on which the resin layer is provided may be subjected to a mold release treatment. Further, sputtered or ultrathin copper foil may be formed on the surface of the support film on which the resin layer is provided.

The protective film is provided on the surface opposite to the support film of the resin layer for the purpose of preventing dust and the like from adhering to the surface of the resin layer of the laminated film and improving handleability. As the protective film, for example, a film made of the thermoplastic resin exemplified in the support film, surface-treated paper, and the like can be used, and among these, a polyester film, a polyethylene film, and a polypropylene film are preferable. The thickness of the protective film is not particularly limited, but is appropriately selected in the range of approximately 10 to 150 μm according to the application. The surface of the protective film on which the resin layer is provided may be subjected to a mold release treatment.

As the film (B), a commercially available film having a 5% elongation load per unit width at 80 ° C. of more than 90 g / mm and 500 g / mm or less may be used. Examples thereof include Diafoil R310 manufactured by Mitsubishi Plastics, Lumirror T6AM manufactured by Toray Industries, Toyobo Ester Film E5041 manufactured by Toyobo Co., Ltd., and Emblet PTHA manufactured by Unitika Ltd.

((C) film)
As the film (C), for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a polyethylene naphthalate (PEN) film or the like can be used. Considering that (C) the film is peeled off when laminating the (A) resin layer on the substrate, the (A) resin layer and (C) are more than the adhesive force between the (A) resin layer and the (B) film. ) It is preferable that the adhesive force with the film is reduced. Further, the film mentioned in the example of the film (B) can also be used as the film (C). The film (C) is preferably a protective film.

The laminated film of the present invention can be preferably used for forming a permanent protective film for a printed wiring board, and above all, can be preferably used for forming a solder resist layer, an interlayer insulating layer, and a coverlay for a flexible printed wiring board. Further, the laminated film of the present invention may form a wiring board by laminating wiring. It can also be used as a sealing resin for semiconductor chips.

The laminated film of the present invention can be suitably used because the resin layer is less likely to wrinkle even when vacuum laminating under heating conditions, for example, 40 to 160 ° C. is adopted as the method for attaching the laminated film. The heating conditions are preferably 50 to 150 ° C, more preferably 50 to 130 ° C. Further, from the viewpoint of circuit followability, it can be suitably used for forming a printed wiring board provided with a finely patterned circuit in which vacuum lamination is adopted under heating conditions. The laminated film of the present invention is preferably laminated on a wiring board and then flattened by a hot press. The hot press is performed, for example, at 40 to 160 ° C., preferably 50 to 150 ° C., more preferably 50 to 130 ° C.

Hereinafter, the present invention will be specifically described with reference to Examples, Comparative Examples, and Test Examples of the present invention, but it goes without saying that the present invention is not limited to the following Examples. In the following, "part" and "%" are all based on mass unless otherwise specified.

(Synthesis of Carboxyl Group-Containing Resin A-1)
In an autoclave equipped with a thermometer, a nitrogen introduction device and an alkylene oxide introduction device, and a stirring device, 119.4 g of a novolak type cresol resin (Shonol CRG951 manufactured by Showa Denko Co., Ltd., OH equivalent: 119.4) and potassium hydroxide 1. 19 g and 119.4 g of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 g of propylene oxide was gradually added dropwise, and the mixture was reacted at ^{125 to 132 ° C. and 0 to 4.8 kg / cm 2 for 16 hours.} Then, the mixture was cooled to room temperature, and 1.56 g of 89% phosphoric acid was added to and mixed with this reaction solution to neutralize potassium hydroxide, and the non-volatile content was 62.1% and the hydroxyl value was 182.2 g / eq. A propylene oxide reaction solution of the novolak type cresol resin was obtained. The obtained novolak-type cresol resin had an average of 1.08 mol of alkylene oxide added per equivalent amount of phenolic hydroxyl groups.

293.0 g of the alkylene oxide reaction solution of the obtained novolak type cresol resin, 43.2 g of acrylic acid, 11.53 g of methanesulfonic acid, 0.18 g of methylhydroquinone and 252.9 g of toluene were mixed with a stirrer and a thermometer. And a reactor equipped with an air blowing tube was charged, air was blown at a rate of 10 ml / min, and the reaction was carried out at 110 ° C. for 12 hours with stirring. As for the water produced by the reaction, 12.6 g of water was distilled off as an azeotropic mixture with toluene. Then, the mixture was cooled to room temperature, the obtained reaction solution was neutralized with 35.35 g of a 15% aqueous sodium hydroxide solution, and then washed with water. Then, toluene was distilled off while substituting 118.1 g of diethylene glycol monoethyl ether acetate with an evaporator to obtain a novolak type acrylate resin solution. Next, 332.5 g of the obtained novolak type acrylate resin solution and 1.22 g of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was blown at a rate of 10 ml / min. While stirring, 62.3 g of tetrahydrophthalic anhydride was gradually added and reacted at 95 to 101 ° C. for 6 hours to obtain a resin having a solid content of 88 mgKOH / g and a carboxyl group-containing photosensitive resin having a solid content of 71%. A solution was obtained. Hereinafter, this is referred to as varnish A-1.

(Synthesis of Carboxyl Group-Containing Resin A-2)
600 g of diethylene glycol monoethyl ether acetate and 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) 1070 g (number of glycidyl groups (total number of aromatic rings): 5 .0 mol), 360 g (5.0 mol) of acrylic acid, and 1.5 g of hydroquinone were charged and heated and stirred at 100 ° C. to uniformly dissolve. Then, 4.3 g of triphenylphosphine was charged, heated to 110 ° C. for 2 hours, then heated to 120 ° C. and further reacted for 12 hours. 415 g of aromatic hydrocarbon (Solbesso 150) and 456.0 g (3.0 mol) of tetrahydrophthalic anhydride were charged into the obtained reaction solution, and the reaction was carried out at 110 ° C. for 4 hours to cool the mixture. In this way, a resin solution having a solid acid value of 89 mgKOH / g and a solid content of 65% was obtained. Hereinafter, this is referred to as varnish A-2.

(Adjustment of photosensitive resin composition)
According to the formulation shown in the table below, each component was compounded, premixed with a stirrer, dispersed with a three-roll mill, and kneaded to prepare the first solution and the second solution. The obtained first liquid and the second liquid were blended to prepare the photosensitive resin compositions IV to V. The blending amount in the table indicates a part by mass.

Ａ−１：上記で得たカルボキシル基含有樹脂ワニスＡ−１
Ａ−２：上記で得たカルボキシル基含有樹脂ワニスＡ−２
＊１：Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｂｌｕｅ １５：３
＊２：Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｙｅｌｌｏｗ１４７
＊３：ＩＲＧＡＮＯＸ１０１０：ＢＡＳＦジャパン社製
＊４：２−メルカプトベンゾチアゾール（アクセルＭ：川口化学工業社製）
＊５：シリカ
＊６：硫酸バリウム（Ｂ−３０：堺化学社製）
＊７：タルク（ＳＧ−２０００：日本タルク社製）
＊８：ハイドロタルサイト（ＤＨＴ−４Ａ：共和化学工業社製）
＊９：１−メトキシプロピル−２−アセテート
＊１０：ジペンタエリスリトールヘキサアクリレート
＊１１：ビフェニルノボラック型エポキシ樹脂（ＮＣ３０００ＨＣＡ７５：日本化薬社製：軟化点７０℃）
＊１２：ビキシレノール型エポキシ樹脂（ＹＸ−４０００：三菱化学社製：融点１０５℃）
＊１３：フェノールノボラック型エポキシ樹脂（ＲＥ３０６ＣＡ９０：日本化薬社製：軟化点５０℃）
＊１４：２−メチル−１−（４−メチルチオフェニル）−２−モルフォリノプロパン−１−オン（イルガキュア９０７：ＢＡＳＦジャパン社製）
＊１５：２，４−ジエチルチオキサントン（ＫＡＹＡＣＵＲＥ ＤＥＴＸ−Ｓ：日本化薬社製）
＊１６：２，４，６−トリメチルベンゾイル−ジフェニル−フォスフィンオキサイド（ルシリンＴＰＯ：ＢＡＳＦジャパン社製）
＊１７：エタノン，１−［９−エチル−６−（２−メチルベンゾイル）−９Ｈ−カルバゾール−３−イル］−，１−（０−アセチルオキシム）（イルガキュア ＯＸＥ０２：：ＢＡＳＦジャパン社製）
＊１８：ジエチレングリコールモノエチルエーテルアセテート

A-1: Carboxyl group-containing resin varnish obtained above A-1
A-2: Carboxyl group-containing resin varnish obtained above A-2
* 1: C.I. I. Pigment Blue 15: 3
* 2: C.I. I. Pigment Yellow 147
* 3: IRGANOX1010: manufactured by BASF Japan Ltd. * 4: 2-mercaptobenzothiazole (Axel M: manufactured by Kawaguchi Chemical Industry Co., Ltd.)
* 5: Silica * 6: Barium sulfate (B-30: manufactured by Sakai Chemical Co., Ltd.)
* 7: Talc (SG-2000: manufactured by Japan Talc)
* 8: Hydrotalcite (DHT-4A: manufactured by Kyowa Kagaku Kogyo Co., Ltd.)
* 9: 1-methoxypropyl-2-acetate * 10: Dipentaerythritol hexaacrylate * 11: Biphenyl novolac type epoxy resin (NC3000HCA75: manufactured by Nippon Kayaku Co., Ltd .: softening point 70 ° C)
* 12: Bixylenol type epoxy resin (YX-4000: manufactured by Mitsubishi Chemical Corporation: melting point 105 ° C)
* 13: Phenolic novolac type epoxy resin (RE306CA90: manufactured by Nippon Kayaku Co., Ltd .: softening point 50 ° C)
* 14: 2-Methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one (Irgacure 907: manufactured by BASF Japan Ltd.)
* 15: 2,4-Diethylthioxanthone (KAYACURE DETX-S: manufactured by Nippon Kayaku Co., Ltd.)
* 16: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (Lucillin TPO: manufactured by BASF Japan Ltd.)
* 17: Etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (0-acetyloxime) (Irgacure OXE02 :: BASF Japan Ltd.)
* 18: Diethylene glycol monoethyl ether acetate

(Measurement of melt viscosity of resin layer material)
A mixed diluent obtained by diluting each of the photosensitive resin compositions I to V obtained above with methyl ethyl ketone was applied to a polyethylene terephthalate film having a thickness of 25 μm with a 90 μm applicator, dried at 80 ° C. for 15 minutes, and the resin layer 1 ~ V was obtained. The films were peeled from the obtained resin layers I to V and superposed to form a sample having a thickness of 300 μm. Using this sample, using Rheo Stress RS-6000 (manufactured by HAAKE), 80 under the conditions of oscillation mode, stress control method, heating rate 5 ° C./min, control stress 3Pa, gap 260 μm, frequency 1 Hz. The melt viscosity at ° C was measured. The results are shown in Table 2.

(Measurement of 5% elongation load (EL80 value) per unit width of film at 80 ° C.)
The film (B) shown in Table 3 below is cut into strips having a length of 50 mm and a width of 3 mm, attached to RSA-G2 manufactured by TA at room temperature with a chuck distance of 30 mm, kept at a temperature of 80 ° C., and then pulled. A tensile test was performed at a speed of 30 mm / min, and the value obtained by dividing the load when the sample showed an elongation of 5% by the width of the sample was taken as the EL80 value (g / mm). The test was performed 5 times in each of the vertical and horizontal directions of the film, and the second largest value was recorded as the maximum value and the second smallest value as the minimum value.

(Preparation of laminated film)
On the film (B) shown in Table 3 below, a mixed diluted solution obtained by diluting the photosensitive resin composition obtained above with methyl ethyl ketone was applied so as to have a thickness of 20 μm after drying, and the mixture was applied at 80 ° C. It was dried with warm air for 1 minute to obtain a photosensitive resin layer (A). Next, as a (C) film, a biaxially stretched polypropylene film (manufactured by Oji Elfan Co., Ltd., MA) having a thickness of 15 μm was laminated on the resin layer (A) to prepare a laminated film. The obtained laminated film was wound so that the film (C) was on the outside to obtain laminated films of Examples 1 to 8 and Comparative Example 1.

(Preparation of evaluation substrate a for evaluation of sticking performance)
A circuit pattern substrate having a copper thickness of 25 μm and a minimum circuit-to-circuit width of 100 μm was subjected to a copper surface roughness treatment using MEC Etch Bond CZ-8101 manufactured by MEC, washed with water, and dried. The laminated films of Examples 1 to 8 and Comparative Example 1 were applied to the obtained dried substrate in a first chamber at a temperature of 80 ° C. using a vacuum laminator (CVP-300: manufactured by Nichigo Morton) at a vacuum pressure of 3 hPa. After laminating under a vacuum under the condition of a vacuum 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 prepare an evaluation substrate a for evaluation of adhesion performance.

(Preparation of evaluation substrate b for evaluation of sticking performance)
The evaluation substrate a for evaluating the sticking performance prepared above was flattened by pressing with a stainless steel plate at a press pressure of ^{8 kgf / m 2 for 60 seconds in a second chamber at a temperature of 80 ° C.} An evaluation substrate b for evaluation of sticking performance was produced.

(Evaluation of wrinkles after vacuum lamination under heating conditions)
The presence or absence of wrinkles on the surface of the evaluation substrate a for evaluating the sticking performance prepared above was visually confirmed through the film (B), and evaluation was performed according to the following criteria. The evaluation was performed 5 times. The results are shown in Table 2.
◯: No wrinkles on all evaluation boards ×: Wrinkles with a length of 1 cm or more on one or more evaluation boards

(Evaluation of wrinkles after flattening by hot press)
The presence or absence of wrinkles on the surface of the evaluation substrate b for evaluating the sticking performance prepared above was visually confirmed through the film (B), and evaluation was performed according to the following criteria. The evaluation was performed 5 times. The results are shown in Table 2.
◯: No wrinkles on all evaluation boards ×: Wrinkles with a length of 1 cm or more

(Preparation of evaluation substrate c for evaluation of sticking performance)
An evaluation substrate c was prepared by exposing the entire surface of a substrate prepared by the same method as the evaluation substrate b except that a solid copper substrate having a plate thickness of 0.8 mm was used using an exposure apparatus equipped with a high-pressure mercury lamp. ..

(Auto peeler test)
Using the evaluation substrate c, the film (B) was formed under the conditions of a kicker roll pressure of 0.4 MPa, a release tape pressing pressure of 0.4 MPa, and a release speed of 15 m / min using a film release device for printed circuit boards manufactured by Hitachi Plant Mechanics. It was peeled off and evaluated under the following conditions. The evaluation was performed 5 times.
◯: The (B) film could be peeled off from the resin layer on all the evaluation substrates. ×: (B) The film was torn and remained in the (A) resin layer after exposure.

(Preparation of evaluation substrate d for evaluation of cured product characteristics)
The evaluation substrate b for evaluating the sticking performance produced above was exposed via a step tablet (Kodak No. 2) using an exposure apparatus equipped with a high-pressure mercury lamp. Development (30 ° C, 0.2 MPa, 1% by mass sodium carbonate aqueous solution) is performed in 90 seconds, and the exposure amount when the pattern of the remaining step tablet is 7 steps is set as the optimum exposure amount, and the pattern is formed with the optimum exposure amount. A cured product was formed. This substrate was irradiated with ultraviolet rays under the condition of an integrated exposure of 1000 mJ / cm ^{2 in} a UV conveyor furnace, and then heated at 150 ° C. for 90 minutes to be cured, and a patterned cured product was formed for evaluation of the characteristics of the cured product. An evaluation substrate d was prepared.

(Resolution)
An evaluation substrate b'was produced in the same manner as the evaluation substrate b for evaluation of adhesion performance, except that a copper-clad laminated substrate was used instead of the circuit pattern substrate having a copper thickness of 25 μm and a minimum inter-circuit width of 100 μm. With respect to the produced evaluation substrate b', an evaluation substrate e for evaluating cured product characteristics was produced in the same manner as the evaluation substrate d for evaluating cured product characteristics, except that an opening pattern of 150 μm was used as the opening forming pattern. The opening shape of the prepared evaluation substrate e for evaluating the characteristics of the cured product was observed with an SEM (scanning electron microscope) and evaluated according to the following criteria. The evaluation was performed 5 times. The results are shown in Table 2.
◯: A stable opening shape was obtained without halation or undercut ×: A stable opening shape was not obtained due to halation or undercut.

(Solder heat resistance)
A rosin-based flux was applied to the evaluation substrate d for evaluating the characteristics of the cured product prepared above, and then the substrate was immersed in a solder bath set at 260 ° C. in advance. Then, after washing the flux with the modified alcohol, the swelling and peeling of the resist layer was visually observed, and the evaluation was performed according to the following criteria. The results are shown in Table 2.
⊚: No peeling is observed in the resist layer even after repeating the immersion for 10 seconds four times or more. ○: No peeling is observed in the resist layer even after repeating the immersion for 10 seconds twice. ×: The resist is immersed for 10 seconds within one time. There is swelling and peeling in the layer

＊１９：三菱樹脂社製ダイアホイルＲ３１０（ポリエチレンテレフタレートフィルム）
＊２０：東レ社製ルミラーＴ６ＡＭ（ポリエチレンテレフタレートフィルム）
＊２１：東洋紡社製東洋紡エステルフィルムＥ５０４１（ポリエチレンテレフタレートフィルム）
＊２２：ユニチカ社製エンブレットＰＴＨＡ（ポリエチレンテレフタレートフィルム）
＊２３：東レ社製ルミラー１２Ｆ６８（ポリエチレンテレフタレートフィルム）

* 19: Mitsubishi Plastics Diafoil R310 (polyethylene terephthalate film)
* 20: Toray Industries, Inc. Lumirror T6AM (polyethylene terephthalate film)
* 21: Toyobo Ester Film E5041 (polyethylene terephthalate film) manufactured by Toyobo Co., Ltd.
* 22: Unitika Embret PTFE (polyethylene terephthalate film)
* 23: Toray Industries, Inc. Lumirror 12F68 (polyethylene terephthalate film)

From the results shown in Table 3 above, in the case of the laminated film of the example, wrinkles are less likely to occur even after vacuum laminating under heating conditions, and even if the film is peeled off with an auto peeler, the film is on the resin layer. It can be seen that it is difficult to remain in. On the other hand, in the case of Comparative Example 1 using a film in which the 5% elongation load per unit width at 80 ° C. does not satisfy more than 90 g / mm and 500 g / mm or less, wrinkles occur after vacuum lamination under heating conditions, and the wrinkled portion. It can be seen that the resolution and the heat resistance of the solder are lowered due to the decrease in the film thickness of the film, and that the film remains on the resin layer when the film is peeled off by the auto peeler.

(A) Resin layer (B) Film (C) film having a 5% elongation load per unit width at 80 ° C. of more than 90 g / mm and 500 g / mm or less.

Claims (5)

A laminated film in which a resin layer (A) and a polyethylene terephthalate film having a 5% elongation load per unit width at 80 ° C. of more than 90 g / mm and 500 g / mm or less are laminated.
The melt viscosity of the resin layer (A) at 80 ° C. is 10 to 10000 dPa · s.
The resin layer (A) is a photosensitive resin layer containing a carboxyl group-containing resin, a photopolymerization initiator, a compound having an ethylenically unsaturated bond, a thermosetting resin, and a filler.
The (B) polyethylene terephthalate film is a peeling layer that can be peeled off from the (A) resin layer .
The 5% elongation load per unit width at 80 ° C. was obtained by holding a strip-shaped sample having a length of 50 mm and a width of 3 mm of the polyethylene terephthalate film (B) at a temperature of 80 ° C. and then pulling it at a tensile speed of 30 mm / min. A laminated film obtained by performing a tensile test and dividing the load when the sample shows an elongation of 5% by the width of the sample. The laminated film according to claim 1, wherein the laminated film is used by being attached to the surface of a wiring board. The laminated film according to claim 2, wherein the laminated film is attached to the surface of a wiring board using a vacuum laminator. The laminated film according to claim 3, wherein the laminated film is attached to the surface of a wiring board by a laminating treatment using a vacuum laminator and a subsequent flattening treatment by a hot press. The laminated film according to any one of claims 1 to 4, which is used for forming a permanent film of a wiring board.

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