Multilayer body, cured product, printed wiring board provided with said cured product, and method for producing same

Abstract

[Problem] The present invention provides a multilayer body which is capable of efficiently forming an insulating layer that has achieved a good balance between excellent via formability and high dielectric characteristics.　[Solution] Disclosed is a multilayer body which comprises a first film and two resin composition layers, wherein: a layer of a photosensitive resin composition, which has solubility or swellability with respect to an alkaline aqueous solution, is formed on one surface of the first film; a layer of a non-photosensitive resin composition, which has solubility or swellability with respect to an organic solvent, is formed on a surface of the layer of a photosensitive resin composition, the surface being on the reverse side of the surface that is in contact with the first film; and the ratio of the dissolution rate A of a cured product layer, which is obtained by photocuring the layer of a photosensitive resin composition, in an organic solvent to the dissolution rate B of the layer of a non-photosensitive resin composition in the organic solvent is regulated to be within a specific range.

Description

Laminate, cured product, printed wiring board including the cured product, and method for manufacturing the same

[0001] The present invention relates to a laminate, particularly to a laminate suitable for use in forming an insulating layer. The present invention also relates to a cured product of a resin composition of the laminate, a printed wiring board including the cured product, and a method for producing the same.

[0002] Conventionally, in the manufacture of multilayer printed wiring boards, a thermosetting resin composition primarily composed of an epoxy resin is generally used as an insulating layer, and vias are formed in the cured product of the thermosetting resin composition using a carbon dioxide laser to provide electrical continuity between layers. Furthermore, in the manufacture of so-called build-up boards, dry-film-type resin compositions are generally used to form the insulating layer. Such dry-film-type resin compositions have the advantage of being able to form a flat resin composition layer by thermocompression bonding to the surface of a printed wiring board using a laminator, thereby facilitating the creation of highly multilayered printed wiring boards.

[0003] In recent years, semiconductor packages equipped with build-up substrates have become smaller in diameter as their performance improves, and the number of vias is also on the rise. To meet these requirements for semiconductor packages equipped with build-up substrates, it is difficult to form small-diameter vias using conventional carbon dioxide lasers, while via formation using UV-YAG lasers allows the formation of small-diameter vias, but has the problems of slow via formation speed and high manufacturing costs.

[0004] Therefore, instead of conventional via formation using a carbon dioxide laser or a UV-YAG laser, via formation using photolithography is being considered. For example, Patent Document 1 proposes a technology for via formation using a photosensitive build-up film.

[0005] However, in recent photolithography, development using an alkaline solution has become mainstream, and in order to enable development using such an alkaline solution, it is necessary for the resin composition to contain many highly polar functional groups such as carboxyl groups and phenolic hydroxyl groups, as in the technology proposed in Patent Document 1. Therefore, a cured product (insulating layer) formed from such a resin composition has a problem in that it is limited in terms of the high dielectric properties (low dielectric constant, low dielectric loss tangent, etc.) that are originally required of an insulating layer.

[0006] Patent Document 1: JP 2012-97246 A Summary of the Invention Problems to be Solved by the Invention

[0007] Under these circumstances, a technical challenge exists to provide a laminate that can efficiently form an insulating layer that has both excellent via formability and excellent dielectric properties as an insulating layer.

[0008] Therefore, an object of the present invention is to provide a laminate capable of efficiently forming an insulating layer that combines such excellent via formation properties with high dielectric properties. Another object of the present invention is to provide a cured product obtained by curing the resin composition layer of the laminate, a printed wiring board including the cured product, and a method for producing the same.

[0009] As a result of extensive research, the present inventors have discovered that the above-mentioned problems can be solved by providing a laminate having a first film and two resin composition layers, with a layer of a photosensitive resin composition that is soluble or swellable in an alkaline aqueous solution on one side of the first film, and a layer of a non-photosensitive resin composition that is soluble or swellable in an organic solvent on the side of the photosensitive resin composition layer opposite the side that contacts the first film, and adjusting the ratio of the dissolution rate A [μm / s] in an organic solvent of the cured product layer obtained by photocuring the photosensitive resin composition layer to the dissolution rate B [μm / s] in an organic solvent of the non-photosensitive resin composition layer to fall within a specific range. The present invention is based on this discovery. Specifically, the gist of the present invention is as follows.

[0010] [1] A laminate comprising: a first film; a layer of a photosensitive resin composition soluble or swellable in an alkaline aqueous solution, provided on one surface of the first film; and a layer of a non-photosensitive resin composition soluble or swellable in an organic solvent, provided on the surface of the photosensitive resin composition layer opposite the surface in contact with the first film, wherein the ratio M=B / A of the dissolution rate A [μm / s] in an organic solvent of the cured product layer obtained by photocuring the photosensitive resin composition layer to the dissolution rate B [μm / s] of the non-photosensitive resin composition layer in an organic solvent satisfies 7≦M. [2] The laminate according to [1], wherein the photosensitive resin composition contains one or both of a carboxyl group-containing resin and a hydroxyl group-containing resin. [3] The laminate according to [1] or [2], wherein the non-photosensitive resin composition contains a thermosetting resin. [4] The laminate according to any of [1] to [3], wherein the laminate is used for forming an insulating layer. [5] A method for manufacturing a printed wiring board having an insulating layer, comprising: (a) laminating a substrate and the laminate according to claim 1 so that one surface of the substrate is in contact with a surface of a layer of a non-photosensitive resin composition of the laminate; (b) irradiating the layer of the photosensitive resin composition of the laminate with light in a pattern to cure it; (c) contacting the layer of the photosensitive resin composition cured in a pattern with an alkaline aqueous solution and developing it to form a cured product of the patterned photosensitive resin composition; (d) contacting the layer of the non-photosensitive resin composition of the laminate with an organic solvent through the cured product of the photosensitive resin composition in a pattern to form a pattern in the layer of the non-photosensitive resin composition corresponding to the pattern of the cured product of the photosensitive resin composition; and (e) heating the layer of the non-photosensitive resin composition on which the pattern has been formed to cure it, to form the insulating layer. [6] The manufacturing method according to [5], further comprising: (f) removing the cured product of the photosensitive resin composition in a pattern. Effect of the invention

[0011] According to the present invention, it is possible to provide a laminate capable of efficiently forming an insulating layer that has both excellent via-formability and high dielectric properties, a cured product obtained by curing a layer of a resin composition of the laminate, a printed wiring board including the cured product, and a method for manufacturing the same. In particular, according to the present invention, it is possible to achieve both excellent via-formability and high dielectric properties in an insulating layer, which are considered difficult to achieve in pattern formation of an insulating layer by photolithography.

[0012] [Laminate] The laminate of the present invention comprises a first film, a layer of a photosensitive resin composition soluble or swellable in an alkaline aqueous solution provided on one side of the first film, and a layer of a non-photosensitive resin composition soluble or swellable in an organic solvent provided on the side of the photosensitive resin composition layer opposite the side in contact with the first film, wherein the ratio of the dissolution rate A [μm / s] in an organic solvent of the cured layer (hereinafter simply referred to as the "cured layer of the photosensitive resin composition") obtained by photocuring the photosensitive resin composition layer to the dissolution rate B [μm / s] of the non-photosensitive resin composition layer in an organic solvent is adjusted to be within a specific range. That is, the laminate of the present invention is a laminate in which the first film, the layer of the photosensitive resin composition, and the layer of the non-photosensitive resin composition are laminated in this order. The laminate of the present invention is preferably used as a dry film, more preferably used as a dry film for forming an insulating layer, particularly preferably used as a dry film for forming an interlayer insulating layer of a multilayer printed wiring board.

[0013] The laminate of the present invention may have other layers in addition to the first film and each resin composition layer. For example, an intermediate layer may be provided between the first film and the photosensitive resin composition layer, or between the photosensitive resin composition layer and the non-photosensitive resin composition layer, or a second film may be provided on the surface of the non-photosensitive resin composition layer opposite to the surface in contact with the photosensitive resin composition layer. Hereinafter, each element constituting the laminate of the present invention will be described in detail.

[0014] <Photosensitive Resin Composition Layer> (Photosensitive Resin Composition) The photosensitive resin composition constituting the photosensitive resin composition layer can be any photocurable resin composition that is soluble or swellable in an alkaline aqueous solution. Examples of such resin compositions include resin compositions containing, as a main component, a photocurable resin having functional groups such as a carboxyl group or a hydroxyl group (including a phenolic hydroxyl group). One type of such photocurable resin may be used alone, or two or more types may be used in combination.

[0015] The photosensitive resin composition may be a composition containing a carboxyl group-containing resin. The carboxyl group-containing resin may be any of various conventionally known resins having carboxyl groups in the molecule. By including a carboxyl group-containing resin in the photosensitive resin composition, the layer of the photosensitive resin composition can be imparted with alkaline developability. In particular, a photosensitive carboxyl group-containing resin having an ethylenically unsaturated double bond in the molecule is preferred in terms of photocurability and development resistance. The ethylenically unsaturated double bond is preferably derived from acrylic acid, methacrylic acid, or a derivative thereof. When using only a carboxyl group-containing resin without an ethylenically unsaturated double bond, it is necessary to use a compound having multiple ethylenically unsaturated groups in the molecule, i.e., a photopolymerizable monomer, as described below, in combination to make the composition photocurable. Specific examples of carboxyl group-containing resins include the following compounds (which may be either oligomers or polymers):

[0016] (1) Carboxyl group-containing resins obtained by copolymerizing an unsaturated carboxylic acid such as (meth)acrylic acid with an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth)acrylate, or isobutylene.

[0017] (2) Carboxyl group-containing urethane resins obtained by the polyaddition reaction of diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates with carboxyl group-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, and diol compounds such as polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

[0018] (3) Carboxylic acid group-containing photosensitive urethane resins obtained by polyaddition reaction of diisocyanates with partially acid anhydride-modified products of reaction products of bifunctional epoxy resins such as bisphenol A epoxy resins, hydrogenated bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, bixylenol epoxy resins, and biphenol epoxy resins with monocarboxylic acid compounds having ethylenically unsaturated double bonds such as (meth)acrylic acid, carboxyl group-containing dialcohol compounds, and diol compounds.

[0019] (4) A carboxyl group-containing photosensitive urethane resin that is (meth)acrylated at the terminal by adding a compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecule, such as a hydroxyalkyl (meth)acrylate, during the synthesis of the resin (2) or (3) described above.

[0020] (5) A carboxyl group-containing photosensitive urethane resin that has been (meth)acrylated at its terminal by adding a compound having one isocyanate group and one or more (meth)acryloyl groups in the molecule, such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate, during the synthesis of the resin (2) or (3) described above.

[0021] (6) A carboxyl group-containing photosensitive resin obtained by reacting a difunctional or more polyfunctional (solid) epoxy resin with (meth)acrylic acid and adding a dibasic acid anhydride to the hydroxyl group present in the side chain.

[0022] (7) A carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy resin in which the hydroxyl groups of a bifunctional (solid) epoxy resin are further epoxidized with epichlorohydrin with (meth)acrylic acid, and then adding a dibasic acid anhydride to the resulting hydroxyl groups.

[0023] (8) Carboxyl group-containing polyester resins obtained by reacting a dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid with a bifunctional oxetane resin, and then adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the resulting primary hydroxyl groups.

[0024] (9) A carboxyl group-containing photosensitive resin obtained by reacting an epoxy compound having multiple epoxy groups in one molecule with a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, such as p-hydroxyphenethyl alcohol, and an unsaturated group-containing monocarboxylic acid, such as (meth)acrylic acid, and then reacting the alcoholic hydroxyl groups of the resulting reaction product with a polybasic acid anhydride, such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, or adipic acid.

[0025] (10) A carboxyl group-containing photosensitive resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide, reacting the resulting reaction product with an unsaturated group-containing monocarboxylic acid, and then reacting the resulting reaction product with a polybasic acid anhydride.

[0026] (11) A carboxyl group-containing photosensitive resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate, reacting the resulting reaction product with an unsaturated group-containing monocarboxylic acid, and then reacting the resulting reaction product with a polybasic acid anhydride.

[0027] (12) A carboxyl group-containing photosensitive resin obtained by further adding a compound having one epoxy group and one or more (meth)acryloyl groups in one molecule to the resins (1) to (11). In this specification, the term "(meth)acrylate" is a general term for acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

[0028] The acid value of the carboxyl group-containing resin is preferably 30 to 150 mgKOH / g, more preferably 50 to 120 mgKOH / g. When the acid value of the carboxyl group-containing resin is 30 mgKOH / g or more, the alkaline developability of the photosensitive resin composition is improved. On the other hand, when the acid value of the carboxyl group-containing resin is 150 mgKOH / g or less, dissolution of the exposed area by a developer and the resulting indiscriminate dissolution and peeling of the exposed and unexposed areas can be suppressed, making it easier to draw a good resist pattern.

[0029] The weight-average molecular weight of the carboxyl group-containing resin varies depending on the resin skeleton, but is generally preferably 2,000 to 150,000, more preferably 5,000 to 100,000. By ensuring that the weight-average molecular weight of the carboxyl group-containing resin is 2,000 or more, it is possible to suppress film loss during development due to a decrease in the moisture resistance of the coating film after exposure of the photosensitive resin composition, thereby suppressing a decrease in via formability. On the other hand, by ensuring that the weight-average molecular weight of the carboxyl group-containing resin is 150,000 or less, it is possible to improve the developability and storage stability of the photosensitive resin composition. The weight-average molecular weight of the carboxyl group-containing resin can be measured by gel permeation chromatography (GPC).

[0030] As the photosensitive resin composition, a composition containing a hydroxyl group-containing resin can be used in place of the above-mentioned carboxyl group-containing resin or in combination with the carboxyl group-containing resin. As the hydroxyl group-containing resin, a phenolic hydroxyl group-containing resin is preferably used. In this specification, the term "hydroxyl group-containing resin" refers to a resin that contains hydroxyl groups but does not contain carboxyl groups. Specific examples of hydroxyl group-containing resins include the following compounds (which may be either oligomers or polymers):

[0031] (1) A functional hydroxyl group-containing resin obtained by copolymerizing a compound having a hydroxyl group and a (meth)acrylic group (e.g., a hydroxy lower alkyl (meth)acrylate) with an unsaturated group-containing compound such as a lower alkyl (meth)acrylate or isobutylene.

[0032] (2) Phenolic hydroxyl group-containing resins having various skeletons, synthesized using compounds having one or more skeletons such as a biphenyl skeleton, a phenylene skeleton, etc., and having a phenolic hydroxyl group, or phenolic hydroxyl group-containing compounds such as phenol, orthocresol, para-cresol, meta-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, catechol, resorcinol, hydroquinone, methylhydroquinone, 2,6-dimethylhydroquinone, trimethylhydroquinone, pyrogallol, and phloroglucinol.

[0033] (3) Well-known and commonly used phenolic resins, such as phenol novolac resins, alkylphenol volac resins, bisphenol A novolac resins, dicyclopentadiene-type phenolic resins, Xylok-type phenolic resins, terpene-modified phenolic resins, polyvinylphenols, bisphenol F, bisphenol S-type phenolic resins, poly-p-hydroxystyrene, condensates of naphthol and aldehydes, and condensates of dihydroxynaphthalene and aldehydes.

[0034] The weight-average molecular weight of the hydroxyl-containing resin varies depending on the resin skeleton, but can be approximately the same as that of the carboxyl-containing resin described above. The weight-average molecular weight of the hydroxyl-containing resin can be measured by gel permeation chromatography (GPC) in the same manner as the carboxyl-containing resin.

[0035] The content of each of the resins in the photosensitive resin composition is not particularly limited as long as the effects of the present invention are achieved, and can be, for example, 10 to 50 mass % in terms of solid content relative to the total mass of the photosensitive resin composition. When multiple types of resins are used in combination, such as a combination of a carboxyl group-containing resin and a hydroxyl group-containing resin, the above content is based on the total mass of the multiple types of resins.

[0036] (Photopolymerizable Monomer) A photopolymerizable monomer can be blended into the photosensitive resin composition as needed. The photopolymerizable monomer is a monomer having an ethylenically unsaturated double bond. Examples of such photopolymerizable monomers include commonly known polyester (meth)acrylates, polyether (meth)acrylates, urethane (meth)acrylates, carbonate (meth)acrylates, and epoxy (meth)acrylates. Specific examples include alkyl acrylates such as 2-ethylhexyl acrylate and cyclohexyl acrylate; hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; mono- or diacrylates of alkylene oxide derivatives such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol; acrylamides such as N,N-dimethylacrylamide, N-methylolacrylamide, and N,N-dimethylaminopropylacrylamide; aminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate and N,N-dimethylaminopropyl acrylate; hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, and trishydroxyethyl isocyanurate. Examples of suitable photopolymerizable monomers include polyhydric alcohols such as those listed above, or polyhydric acrylates such as their alkylene oxide adducts or ε-caprolactone adducts; phenols such as phenoxy acrylate and bisphenol A diacrylate, or polyhydric acrylates such as their alkylene oxide adducts; glycidyl ether acrylates such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; and, without limitation, acrylates and melamine acrylates obtained by directly acridating polyols such as polyether polyols, polycarbonate diols, hydroxyl-terminated polybutadienes, and polyester polyols, or by urethane acrylates via diisocyanates, as well as methacrylates corresponding to the above acrylates. Such photopolymerizable monomers can also be used as reactive diluents.The photopolymerizable monomers may be used alone or in combination of two or more.

[0037] Photopolymerizable monomers are effective, particularly when a non-photosensitive carboxyl group-containing resin that does not have an ethylenically unsaturated double bond is used, because a photopolymerizable monomer must be used in combination to make the composition photocurable.

[0038] (Photopolymerization initiator) A photopolymerization initiator can be blended into the photosensitive resin composition as needed. Any known photopolymerization initiator can be used. One photopolymerization initiator may be used alone, or two or more photopolymerization initiators may be used in combination.

[0039] Specific examples of the photopolymerization initiator include bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, and bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylphenylphosphine oxide. bisacylphosphine oxides such as 2,6-dimethoxybenzoyldiphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, and bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloyl monoacylphosphine oxides such as phenylphosphinic acid isopropyl ester and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate, 1-hydroxy-cyclohexyl phenyl ketone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one hydroxyacetophenones such as benzoin, benzil, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether; benzoin alkyl ethers; benzophenones such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, and 4,4'-bisdiethylaminobenzophenone;Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl)-1-[4-(4-morpholinyl)phenyl]-1-butanone, N,N-dimethylamino Acetophenones such as acetophenone; thioxanthones such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; anthraquinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; acetophenone Ketals such as dimethyl ketal and benzyl dimethyl ketal; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate and p-dimethylbenzoic acid ethyl ester; oxime esters such as 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxime), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime); bis(η5-2,4-cyclopentadien-1-yl)-bis( Titanocenes such as 2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium and bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyr-1-yl)ethyl)phenyl]titanium; alkylphenomorpholinophenylides such as 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholinophenyl)-butan-1-one, 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide, and the like.

[0040] A photoinitiator aid or sensitizer may be used in combination with the above-described photopolymerization initiator. Examples of the photoinitiator aid or sensitizer include benzoin compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, tertiary amine compounds, and xanthone compounds. In particular, it is preferable to use thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, and 4-isopropylthioxanthone. The inclusion of a thioxanthone compound can improve deep curing properties. While these compounds may be used as photopolymerization initiators, it is preferable to use them in combination with a photopolymerization initiator. Furthermore, the photoinitiator aid or sensitizer may be used alone or in combination of two or more.

[0041] These photopolymerization initiators, photoinitiator assistants, and sensitizers absorb specific wavelengths, which can reduce sensitivity in some cases and function as ultraviolet absorbers. However, they are not used solely for the purpose of improving the sensitivity of the photosensitive resin composition. By absorbing light of specific wavelengths as needed, they can increase the photoreactivity of the surface, change the line shape and openings of the resist to vertical, tapered, or reverse tapered, and improve the accuracy of the line width and opening diameter.

[0042] (Filler) The photosensitive resin composition may contain a filler as needed to increase the physical strength and dissolution rate of the coating film. Known inorganic or organic fillers can be used as such fillers, with barium sulfate, spherical silica, hydrotalcite, and talc being particularly preferred. Furthermore, titanium oxide, metal oxides, and metal hydroxides such as aluminum hydroxide can be used as extender pigment fillers to achieve a white appearance and flame retardancy. The filler may or may not be surface-treated. Furthermore, one type of filler may be used alone, or two or more types may be used in combination.

[0043] (Organic Solvent) The curable resin composition of the present invention may contain an organic solvent for the purpose of adjusting the viscosity during preparation and application to a substrate or film. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, and tripropylene glycol monomethyl ether; esters such as ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, and solvent naphtha. The organic solvents may be used alone or in combination of two or more.

[0044] In the present invention, the organic solvent can be evaporated and dried using a hot air circulation drying oven, an IR oven, a hot plate, a convection oven, or the like (a method in which a dryer equipped with a heat source of an air heating type using steam is used, and hot air in the dryer is brought into countercurrent contact with the substrate, or a method in which hot air is blown onto the substrate from a nozzle).

[0045] (Other Additive Components) The photosensitive resin composition may further contain, as needed, components such as colorants, photoinitiator aids, cyanate compounds, elastomers, mercapto compounds, urethanization catalysts, thixotropic agents, adhesion promoters, block copolymers, chain transfer agents, polymerization inhibitors, copper inhibitors, antioxidants, rust inhibitors, thickeners such as organic bentonite and montmorillonite, at least one of silicone-based, fluorine-based, and polymer-based defoamers and leveling agents, silane coupling agents such as imidazole-based, thiazole-based, and triazole-based, flame retardants such as phosphorus compounds such as phosphinates, phosphate ester derivatives, and phosphazene compounds, and thermosetting components. These other additive components may be those known in the field of electronic materials. The other additive components may be used alone or in combination of two or more. The content of the other additive components in the photosensitive resin composition is not particularly limited as long as the effects of the present invention are achieved, and can be appropriately adjusted depending on the type of the other additive components and the desired properties to be imparted to the photosensitive resin composition.

[0046] The photosensitive resin composition layer may be prepared and molded by appropriately selecting the above-mentioned components, or a commercially available product may be used. Examples of commercially available products that can be used as the photosensitive resin composition layer include photosensitive build-up film PV-F008 manufactured by Resonac Co., Ltd.

[0047] <Non-photosensitive resin composition layer> (Non-photosensitive resin composition) The non-photosensitive resin composition constituting the non-photosensitive resin composition layer is not particularly limited, as long as it is a resin composition that is substantially not photocurable, substantially not soluble or swellable in an alkaline aqueous solution, and soluble or swellable in an organic solvent. As such a resin composition, for example, a resin composition containing as a main component a thermosetting resin that is substantially free of functional groups such as carboxyl groups and phenolic hydroxyl groups (i.e., a thermosetting resin composition) can be used.

[0048] Any known thermosetting resin can be used as the thermosetting resin constituting the thermosetting resin composition. For example, known thermosetting resins such as amino resins (e.g., melamine resins, benzoguanamine resins, melamine derivatives, and benzoguanamine derivatives), isocyanate compounds, blocked isocyanate compounds, cyclocarbonate compounds, epoxy compounds, oxetane compounds, oxazoline compounds, episulfide resins, bismaleimides, and carbodiimide resins can be used. Each of these thermosetting resins may be monofunctional or polyfunctional. An epoxy compound (epoxy resin) is preferably used as the thermosetting resin. One type of thermosetting resin may be used alone, or two or more types may be used in combination. Of the above-mentioned thermosetting resins, a thermosetting resin having a cyclic ether group or a cyclic thioether group (hereinafter also referred to as a "cyclic (thio)ether group") in the molecule is preferably used. Specifically, epoxy compounds having an epoxy group in the molecule, oxetane compounds having an oxetanyl group in the molecule, oxazoline compounds having an oxazoline group in the molecule, episulfide resins having a thioether group in the molecule, etc. are preferably used. Particularly preferably, the thermosetting resin contains one or more compounds selected from the group consisting of epoxy compounds, polyfunctional oxetane compounds, and oxazoline compounds. When the non-photosensitive resin composition contains these compounds as the thermosetting resin, the resulting cured product (insulating layer) can be imparted with excellent heat resistance, chemical resistance, and adhesion.

[0049] Examples of epoxy compounds include epoxidized vegetable oils, bisphenol A type epoxy resins, hydroquinone type epoxy resins, bisphenol type epoxy resins, thioether type epoxy resins, brominated epoxy resins, novolac type epoxy resins, phenol novolac type epoxy resins, biphenol novolac type epoxy resins, bisphenol F type epoxy resins, hydrogenated bisphenol A type epoxy resins, glycidylamine type epoxy resins, hydantoin type epoxy resins, alicyclic epoxy resins, trihydroxyphenylmethane type epoxy resins, bixylenol type or biphenol type epoxy resins, and or mixtures thereof; bisphenol S type epoxy resins; bisphenol A novolac type epoxy resins; tetraphenylolethane type epoxy resins; heterocyclic epoxy resins; diglycidyl phthalate resins; tetraglycidyl xylenoylethane resins; naphthalene group-containing epoxy resins; epoxy resins having a dicyclopentadiene skeleton; glycidyl methacrylate copolymer epoxy resins; cyclohexylmaleimide and glycidyl methacrylate copolymer epoxy resins; epoxy-modified polybutadiene rubber derivatives; CTBN-modified epoxy resins, etc., but are not limited to these. These epoxy resins may be used alone or in combination of two or more.

[0050] As the oxetane compound, a polyfunctional oxetane compound having two or more oxetanyl groups in one molecule is preferably used. Examples of the polyfunctional oxetane compound include bis[(3-methyl-3-oxetanylmethoxy)methyl]ether, bis[(3-ethyl-3-oxetanylmethoxy)methyl]ether, 1,4-bis[(3-methyl-3-oxetanylmethoxy)methyl]benzene, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, (3-methyl-3-oxetanyl)methyl acrylate, and (3-ethyl-3-oxetanyl)methyl acrylate. Examples of suitable oxetane compounds include polyfunctional oxetanes such as acrylate, (3-methyl-3-oxetanyl)methyl methacrylate, (3-ethyl-3-oxetanyl)methyl methacrylate, and oligomers or copolymers thereof, as well as ethers of oxetane alcohols with novolak resins, poly(p-hydroxystyrene), cardo-type bisphenols, calixarenes, calixresorcinarenes, or hydroxyl group-containing resins such as silsesquioxane. Other examples include copolymers of unsaturated monomers having an oxetane ring with alkyl (meth)acrylates.

[0051] Examples of oxazoline compounds include compounds having two or more oxazoline groups in one molecule. Examples of such oxazoline compounds include oxazoline group-containing polymers such as polymers of oxazoline group-containing monomers and copolymers of oxazoline group-containing monomers with other monomers. Examples of oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, 2-isopropenyl-2-oxazoline, and 2-isopropenyl-4,4-dimethyl-2-oxazoline.

[0052] The episulfide resin may be, for example, a compound in which an oxygen atom constituting an epoxy group in any epoxy compound is substituted with a sulfur atom. Examples of the epoxy compound include the same compounds as those described above. In addition, a conventionally known method can be used to substitute an oxygen atom constituting an epoxy group in an epoxy compound with a sulfur atom.

[0053] Examples of amino resins such as melamine derivatives and benzoguanamine derivatives include methylolmelamine compounds, methylolbenzoguanamine compounds, methylolglycoluril compounds, and methylolurea compounds.

[0054] The isocyanate compound may be a polyisocyanate compound, such as aromatic polyisocyanates such as 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, and 2,4-tolylene dimer; aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis(cyclohexyl isocyanate), and isophorone diisocyanate; alicyclic polyisocyanates such as bicycloheptane triisocyanate; and adducts, biuret compounds, and isocyanurates of the above-mentioned isocyanate compounds.

[0055] The blocked isocyanate compound can be an addition reaction product of an isocyanate compound and an isocyanate blocking agent. Examples of isocyanate compounds that can react with an isocyanate blocking agent include the polyisocyanate compounds described above. Examples of the isocyanate blocking agent include phenol-based blocking agents, lactam-based blocking agents, active methylene-based blocking agents, alcohol-based blocking agents, oxime-based blocking agents, mercaptan-based blocking agents, acid amide-based blocking agents, imide-based blocking agents, amine-based blocking agents, imidazole-based blocking agents, and imine-based blocking agents.

[0056] The content of the thermosetting resin in the non-photosensitive resin composition is not particularly limited as long as the effects of the present invention are achieved, and can be, for example, 3 to 50 mass % in terms of solid content relative to the total mass of the non-photosensitive resin composition.

[0057] (Thermal Curing Catalyst) The non-photosensitive resin composition may contain a thermal curing catalyst as needed. Examples of the thermal curing catalyst include imidazole derivatives such as 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 2-phenyl-4,5-dihydroxymethylimidazole; amine compounds such as dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, and 4-methyl-N,N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. Commercially available examples include 2MZ-A, 2MZ-OK, 2PHZ, 2PHZ-PW, 2P4BHZ, and 2P4MHZ (all trade names of imidazole-based compounds) manufactured by Shikoku Chemicals Corporation, and U-CAT 3513N (trade name of a dimethylamine-based compound), DBU, DBN, and U-CAT SA 102 (all bicyclic amidine compounds and salts thereof) manufactured by San-Apro Co., Ltd. However, the curing catalyst is not limited to these, and any curing catalyst that promotes the reaction of at least one of an epoxy group and an oxetanyl group with a carboxyl group may be used, and they may be used alone or in combination of two or more. Also usable are S-triazine derivatives such as guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine·isocyanuric acid adduct, and 2,4-diamino-6-methacryloyloxyethyl-S-triazine·isocyanuric acid adduct. Preferably, these compounds that also function as adhesion promoters are used in combination with a heat curing catalyst. The heat curing catalyst may be used alone or in combination of two or more.

[0058] If necessary, the non-photosensitive resin composition may contain one or more of the fillers, organic solvents and other additive components described above for the photosensitive resin composition.

[0059] The layer of the non-photosensitive resin composition may be synthesized and molded by appropriately selecting the above-mentioned components, or a commercially available product may be used. Examples of commercially available products that can be used as the layer of the non-photosensitive resin composition include Zaristo 125 manufactured by Taiyo Ink Mfg. Co., Ltd. and Ajinomoto Build-up Film (registered trademark) (ABF) GX-92, GX-T31, GZ-41, and GL-102 manufactured by Ajinomoto Fine-Techno Co., Ltd.

[0060] The laminate of the present invention is adjusted so that the dissolution rates of the above-mentioned photosensitive resin composition layer and non-photosensitive resin composition layer satisfy a specific relationship when they are separately dissolved in the same organic solvent under the same conditions. Specifically, in the laminate of the present invention, when the dissolution rate of the cured product layer obtained by photocuring the photosensitive resin composition layer in a specific organic solvent is A [μm / s] and the dissolution rate of the non-photosensitive resin composition layer in the same organic solvent is B [μm / s], the ratio M (= B / A) of the two is adjusted to satisfy 7≦M, preferably 10≦M, more preferably 15≦M, and even more preferably 20≦M.

[0061] As described above, the laminate of the present invention has a two-layer structure consisting of a layer of a photosensitive resin composition that is soluble or swellable in an alkaline aqueous solution and a layer of a non-photosensitive resin composition that is soluble or swellable in an organic solvent. The dissolution rate of the photosensitive resin composition layer in an organic solvent and the dissolution rate of the non-photosensitive resin composition layer in an organic solvent are adjusted to satisfy a specific relationship, thereby suppressing the generation of residues during development. Furthermore, it is possible to achieve both excellent via formation and high dielectric properties, which are considered difficult to achieve in the pattern formation of a cured product by photolithography. That is, a substrate and the laminate of the present invention are laminated so that one side of the substrate and the surface of the layer of the non-photosensitive resin composition of the laminate of the present invention are in contact, and the layer of the photosensitive resin composition of the laminate of the present invention is cured into a desired pattern by photolithography. The layer of the non-photosensitive resin composition is then contacted with an organic solvent through the cured product of the photosensitive resin composition in the desired pattern (i.e., as a "mold"), and developed and cured, thereby obtaining a cured product (insulating layer) of the non-photosensitive resin composition in the desired pattern. As described above, the non-photosensitive resin constituting the non-photosensitive resin composition has a low content of highly polar functional groups, such as carboxyl groups and phenolic hydroxyl groups, and therefore the insulating layer formed by the laminate of the present invention can have the high dielectric properties required for an insulating layer. In this specification, "high" or "excellent" with respect to dielectric properties refers to at least one of a low dielectric constant and a low dielectric dissipation factor. Furthermore, as described above, with the laminate of the present invention, a cured product of the photosensitive resin composition having a desired pattern is obtained by photolithography, and the cured product is used as a mold to obtain a cured product of the non-photosensitive resin composition having the desired pattern. This allows for the efficient formation of an insulating layer having a desired pattern with excellent via formation properties compared to conventional pattern formation using a carbon dioxide laser or UV-YAG laser.

[0062] In the present invention, the dissolution rates of the photosensitive resin composition layer and the cured product layer of the non-photosensitive resin composition in the laminate of the present invention are measured according to the procedure described in the Examples.

[0063] In the laminate of the present invention, the first film can be any known film without any particular limitation, and for example, films made of thermoplastic resins such as polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyimide films, polyamideimide films, polypropylene films, and polystyrene films can be suitably used. Among these, from the viewpoints of heat resistance, mechanical strength, handleability, etc., polyester films are preferably used, and PET films are more preferably used. A laminate of these films can also be used as the first film.

[0064] Moreover, from the viewpoint of improving mechanical strength, the thermoplastic resin film as described above is preferably a film that has been oriented in a uniaxial or biaxial direction.

[0065] The thickness of the first film is not particularly limited, but can be, for example, 1 to 150 μm, or 10 to 60 μm.

[0066] The method for providing the photosensitive resin composition layer and the non-photosensitive resin composition layer on the first film can be a well-known method for producing laminates such as dry films. For example, the photosensitive resin composition is diluted with the organic solvent described above to adjust the viscosity to an appropriate level, and then coated to a uniform thickness on the first film using a coating method such as a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater, gravure coater, or spray coater. The resulting coating is typically dried at a temperature of 50 to 130°C for 1 to 30 minutes to obtain a film. Next, the non-photosensitive resin composition is diluted with the organic solvent described above to adjust the viscosity to an appropriate level, and then coated to a uniform thickness on the dried photosensitive resin composition film using the coating method described above. The resulting coating is typically dried at a temperature of 70 to 110°C for 5 to 20 minutes to obtain a film. There are no particular restrictions on the coating thickness of either the photosensitive resin composition or the non-photosensitive resin composition, but as described above, the coating thickness of each resin composition is generally adjusted appropriately so that the film thickness after drying is in the range of 1 to 150 μm, preferably 10 to 60 μm.

[0067] After forming a layer of photosensitive resin composition on the first film and then forming a layer of non-photosensitive resin composition on the layer of non-photosensitive resin composition, it is preferable to laminate a peelable second film on the surface of the layer of non-photosensitive resin composition for the purpose of preventing dust from adhering to the surface of the layer of non-photosensitive resin composition. The second film refers to a film that is peeled from the layer of non-photosensitive resin composition before lamination when the laminate is integrally molded by laminating the layer of non-photosensitive resin composition on a base material such as a substrate by heating or the like. Examples of the peelable second film include polyethylene film, polytetrafluoroethylene film, polypropylene film, and surface-treated paper, as long as the adhesive strength between the layer of non-photosensitive resin composition and the second film is smaller than the adhesive strength between the layer of non-photosensitive resin composition and the layer of photosensitive resin composition when the second film is peeled off.

[0068] The thickness of the second film is not particularly limited, but can be, for example, 10 μm to 150 μm.

[0069] <Cured Product> The cured product of the present invention is obtained by curing the layer of the non-photosensitive resin composition constituting the laminate of the present invention described above. The cured product of the present invention can be suitably used as an insulating layer that combines excellent via-forming properties with excellent (i.e., high) dielectric properties as an insulating layer, and is particularly suitable for use as, for example, a solder resist layer or a build-up material. The cured product of the present invention can be obtained by laminating a substrate and the laminate of the present invention so that one side of the substrate contacts the surface of the layer of the non-photosensitive resin composition of the laminate of the present invention, curing the layer of the photosensitive resin composition of the laminate of the present invention into a desired pattern by photolithography, and contacting the layer of the non-photosensitive resin composition with an organic solvent through the cured product of the photosensitive resin composition of the desired pattern (i.e., as a "mold"), developing and curing, thereby obtaining a cured product (insulating layer) of the non-photosensitive resin composition of the desired pattern. Note that if a pattern-shaped cured product of the photosensitive resin composition remains, the remaining pattern-shaped cured product of the photosensitive resin composition may be removed. The method for removing the remaining cured product of the photosensitive resin composition is not particularly limited as long as it does not damage the substrate, other members, or the cured product of the present invention (i.e., the cured product of the non-photosensitive resin composition). For example, a method for removing the cured product of the photosensitive resin composition using hot water can be mentioned.

[0070] (Printed Wiring Board) The printed wiring board of the present invention has a cured product (insulating layer) of the non-photosensitive resin composition formed by the laminate of the present invention, and the printed wiring board of the present invention can be used as a component of a semiconductor device. The printed wiring board of the present invention is produced by a production method (production method of the present invention) including the following steps (a) to (e): (a) laminating a substrate and a laminate of the present invention so that one side of the substrate contacts the surface of the layer of the non-photosensitive resin composition of the laminate of the present invention; (b) irradiating the layer of the photosensitive resin composition of the laminate of the present invention with light in a pattern to cure it; (c) contacting the pattern-cured layer of the photosensitive resin composition with an alkaline aqueous solution and developing it to form a pattern-cured product of the photosensitive resin composition; (d) contacting the layer of the non-photosensitive resin composition with an organic solvent through the pattern-cured product of the photosensitive resin composition and developing it to form a pattern in the layer of the non-photosensitive resin composition corresponding to the pattern of the cured product of the photosensitive resin composition; and (e) heating the pattern-formed layer of the non-photosensitive resin composition to cure it to form an insulating layer. Each of steps (a) to (e) is described in detail below.

[0071] In step (a), the substrate and the laminate of the present invention are laminated so that one side of the substrate contacts the surface of the layer of the non-photosensitive resin composition of the laminate of the present invention. The laminate of the present invention onto the substrate is preferably performed under pressure and heat using a vacuum laminator or the like. By using such a vacuum laminator, when a circuit-formed substrate is used, even if the circuit board surface is uneven, the dry film adheres to the circuit board, preventing the inclusion of air bubbles and improving the filling of recesses on the substrate surface. The pressure conditions are preferably about 0.1 to 2.0 MPa, and the heating conditions are preferably 40 to 120°C.

[0072] Examples of substrates include printed wiring boards and flexible printed wiring boards on which circuits have been formed in advance using copper or the like, as well as copper-clad laminates for high-frequency circuits made from materials such as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, fluororesin / polyethylene / polyphenylene ether, polyphenylene oxide / cyanate, and the like, including copper-clad laminates of all grades (FR-4, etc.), as well as metal substrates, polyimide films, polyethylene terephthalate films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates, etc.

[0073] In step (b), after laminating the laminate of the present invention on the substrate in the above-mentioned step (a), the layer of the photosensitive resin composition is selectively exposed to active energy rays through a photomask having a desired pattern to be cured. Note that the timing of peeling the first film from the laminate of the present invention is not particularly limited as long as the effects of the present invention are exhibited, and it may be before or after the above-mentioned exposure.

[0074] The exposure device used for exposure with the active energy rays may be a device equipped with a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, or the like, and capable of irradiating ultraviolet rays in the range of 350 to 450 nm. Furthermore, a direct imaging device (for example, a laser direct imaging device that draws an image directly with a laser based on CAD data from a computer) may also be used. The lamp or laser light source of the direct imaging device may have a maximum wavelength in the range of 350 to 450 nm. The exposure dose for image formation varies depending on factors such as the film thickness, but is generally 10 to 1,000 mJ / cm. ２ , preferably 20 to 800 mJ / cm ２ Within the range

[0075] In step (c), after the layer of the photosensitive resin composition has been cured into a desired pattern in step (b) described above, the layer of the photosensitive resin composition cured into the desired pattern is brought into contact with an alkaline aqueous solution for development, thereby forming a cured product of the photosensitive resin composition in the desired pattern.

[0076] The alkaline aqueous solution used for development in the step (c) is not particularly limited as long as it does not cause damage to the substrate, other members, or the layer of the non-photosensitive resin composition, and examples thereof include dilute alkaline aqueous solutions such as a 0.3 to 3 mass % aqueous sodium carbonate solution.

[0077] In order to improve the properties such as adhesion and hardness of the cured product of the photosensitive resin composition in the desired pattern formed in the step (c), the cured product of the photosensitive resin composition in the desired pattern may be further irradiated with active energy rays to perform final finish curing (main curing) of the cured product of the photosensitive resin composition in the desired pattern.

[0078] In step (d), the desired pattern is formed in the layer of non-photosensitive resin composition using the cured product of the photosensitive resin composition in the desired pattern shape formed in the above-mentioned step (c) as a mold. That is, the layer of non-photosensitive resin composition is brought into contact with an organic solvent through the cured product of the photosensitive resin composition in the desired pattern shape, and development is performed, thereby forming a pattern in the layer of non-photosensitive resin composition that corresponds to the desired pattern formed in the cured product of the photosensitive resin composition.

[0079] The organic solvent used as the developer in step (d) is not particularly limited, and examples thereof include acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, an alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and dipropylene glycol methyl ether. One organic solvent may be used alone, or two or more organic solvents may be used in combination. Examples of organic solvents that may be used alone include ethyl acetate, dipropylene glycol, dipropylene glycol methyl ether, 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, γ-butyrolactone, and propylene glycol monomethyl ether acetate (propylene glycol 1-monomethyl ether 2-acetate (PGMEA)). Dipropylene glycol methyl ether is preferably used as the organic solvent.

[0080] The concentration of the organic solvent is not particularly limited as long as it does not damage the substrate or other members, but is preferably 2 to 90% by mass relative to the total mass of the developer. The temperature of the developer can be appropriately set depending on the type and concentration of the organic solvent contained in the developer and the desired developability.

[0081] The method of contacting the layer of the non-photosensitive resin composition with a developer (organic solvent), i.e., the developing method, is not particularly limited as long as it is a method used to develop a cured product of a resin composition, and examples thereof include a dipping method, a bathing method, a spraying method, a high-pressure spraying method, brushing, and slapping. One developing method may be used alone, or two or more developing methods may be used in combination. From the viewpoint of further improving the resolution of the resulting cured product (insulating layer), the high-pressure spraying method is preferably used.

[0082] In step (e), the layer of the non-photosensitive resin composition in the desired pattern formed in step (d) above is heated and cured to form an insulating layer.

[0083] The conditions for heating the layer of non-photosensitive resin composition in the desired pattern are not particularly limited as long as the temperature is the same as that used for curing a thermosetting resin, and are, for example, 150 to 190° C. for 30 to 120 minutes.

[0084] If a patterned cured product of the photosensitive resin composition remains on the printed wiring board after the above-mentioned step (e), the manufacturing method of the present invention may further include a step (f) of removing the remaining patterned cured product of the photosensitive resin composition. The method for removing the remaining cured product of the photosensitive resin composition can be the same method as that described for the cured product above. Examples

[0085] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" and "%" are all by mass unless otherwise specified.

[0086] [Preparation of Photosensitive Resin Composition 1] Photosensitive resin composition 1 used in this example was prepared according to the procedure shown below. 65 parts of a hydrophilic copolymer (monomer composition = 60% butadiene, 9% methyl acrylate, 20% ethylene methacrylate phosphate, 10% styrene, and 1% divinylbenzene), 35 parts of a polystyrene-polybutadiene-polystyrene type block copolymer, 50 parts of liquid polybutadiene (NISSO-PB B1000) manufactured by Nippon Soda Co., Ltd., and 0.2 parts of 2,6-di-t-butyl-p-cresol were kneaded at 150°C until homogeneous, and then the temperature was lowered to 120°C. 10 parts of 1,6-hexanediol diacrylate, 5 parts of 1,6-hexanediol dimethacrylate, 1 part of benzoin methyl ether, and 0.02 parts of methylhydroquinone were added and further kneaded to obtain a photocurable alkali-soluble resin composition (photosensitive resin composition 1). This resin composition was applied to a support film (polyethylene terephthalate (PET) film TN-200, manufactured by Toyobo Co., Ltd., thickness 38 μm, size 30 cm × 30 cm) using a bar coater so that the thickness of the resin composition layer after drying would be 30 μm. Next, it was dried at 70 to 90 ° C (average 80 ° C) for 20 minutes using a hot air circulation drying oven to form a layer of photosensitive resin composition 1 on the support film, thereby forming a laminate (film) having a layer of photosensitive resin composition 1, which was used to prepare an evaluation substrate described below.

[0087] [Preparation of Non-Photosensitive Resin Composition 1] Non-photosensitive resin composition 1 used in this example was prepared according to the procedure described below. 25 parts of biphenyl / phenol novolac epoxy resin NC-3000 manufactured by Nippon Kayaku Co., Ltd., 3 parts of tetramethylbiphenyl epoxy resin jER (registered trademark) YX-4000 manufactured by Mitsubishi Chemical Corporation, 2 parts of bisphenol F epoxy resin jER (registered trademark) 807 manufactured by Mitsubishi Chemical Corporation, 1.5 parts of bisphenol A epoxy resin jER (registered trademark) 828 manufactured by Mitsubishi Chemical Corporation, 1.2 parts of naphthalene epoxy resin EPICLON (registered trademark) HP-4032 manufactured by DIC Corporation, and fluorene / tetramethylbiphenyl skeleton-containing phenoxy resin FX293 manufactured by Nippon Steel Chemical Co., Ltd. 3 parts of benzophenone-3-one, 1.2 parts of HCA-HQ (10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) manufactured by Sanko Co., Ltd., 20 parts of cyclohexanone, and 60 parts of silica SO-C2 manufactured by Admatechs Co., Ltd. were kneaded until homogeneous to obtain a thermosetting resin composition (non-photosensitive resin composition 1). This resin composition was applied to a support film (polyethylene terephthalate (PET) film TN-200 manufactured by Toyobo Co., Ltd., thickness 38 μm, size 30 cm × 30 cm) using a bar coater so that the thickness of the resin composition layer after drying would be 30 μm. Next, the film was dried at 70 to 90°C (average 80°C) for 10 minutes using a hot air circulation drying oven to form a layer of non-photosensitive resin composition 1 on the support film, thereby obtaining a laminate (film) having a layer of non-photosensitive resin composition 1, which was used to prepare an evaluation substrate described later.

[0088] [Preparation of Non-Photosensitive Resin Composition 2] Non-photosensitive resin composition 2 used in this example was prepared according to the procedure described below. 5 parts of bisphenol AF type epoxy resin jER (registered trademark) YX7760 manufactured by Mitsubishi Chemical Corporation, 4 parts of tetramethylbiphenyl type epoxy resin jER (registered trademark) YX-4000 manufactured by Mitsubishi Chemical Corporation, 8 parts of naphthol aralkyl type epoxy resin ESN-475 manufactured by Nippon Steel Chemical Co., Ltd., 5 parts of cresol novolac resin LA-3018 manufactured by DIC Corporation, 5 parts of active ester type curing agent EPICLON (registered trademark) HPC-8000 having a dicyclopentadienyl diphenol structure manufactured by DIC Corporation, 2 parts of imidazole type epoxy resin curing agent Curesol (registered trademark) 1B2PZ manufactured by Shikoku Chemicals Corporation, 20 parts of cyclohexanone, and 70 parts of silica SO-C2 manufactured by Admatechs Co., Ltd. were kneaded until homogeneous to obtain a thermosetting resin composition (non-photosensitive resin composition 2). This resin composition was applied to a support film (polyethylene terephthalate (PET) film TN-200, manufactured by Toyobo Co., Ltd., thickness 38 μm, size 30 cm × 30 cm) using a bar coater so that the thickness of the resin composition layer after drying would be 30 μm. Next, it was dried at 70 to 90 ° C (average 80 ° C) for 10 minutes using a hot air circulation drying oven to form a layer of non-photosensitive resin composition 2 on the support film, and a laminate (film) having a layer of non-photosensitive resin composition 2 was obtained, which was used to prepare an evaluation substrate described below.

[0089] [Preparation of Evaluation Substrates] Each evaluation substrate of the Examples and Comparative Examples was prepared by laminating a layer of the photosensitive resin composition and a layer of the non-photosensitive resin composition shown in Table 1 below on a substrate in the following order: layer of the non-photosensitive resin composition, layer of the photosensitive resin composition, according to the following procedure. Details of each layer in Table 1 are as follows: (X-1) Photosensitive resin composition: a photosensitive resin composition (resin composition containing a hydroxyl group-containing resin) obtained by the above-mentioned Preparation Example of a photosensitive resin composition. (X-2) PSR-800 AUS410: a developable dry film solder resist for PKG substrates (resin composition containing a carboxyl group-containing resin) manufactured by Taiyo Ink Mfg. Co., Ltd. (Y-1) Zaristo 125G: a thermosetting interlayer insulating film (resin composition containing a thermosetting resin) manufactured by Taiyo Ink Mfg. Co., Ltd. (Y-2) Non-photosensitive resin composition 1: a non-photosensitive resin composition obtained by the above-mentioned Preparation Example of a non-photosensitive resin composition 1. (Y-3) Non-photosensitive resin composition 2: a non-photosensitive resin composition obtained by the above-mentioned Preparation Example of a non-photosensitive resin composition 2. Both of the above (X-1) and (X-2) are photocurable and soluble in alkaline solutions. Furthermore, all of the above (Y-1) to (Y-3) are not photocurable but thermosetting, and are soluble in organic solvents.

[0090] A layer (film) of each of the non-photosensitive resin compositions (Y-1) to (Y-3) described above was laminated onto a substrate using a vacuum laminator CVP-300 manufactured by Nikko-Materials Co., Ltd., and allowed to stand at room temperature for at least 1 hour after lamination. The substrate used was an HL832NS substrate (from which the copper foil had been removed by etching) manufactured by Mitsubishi Gas Chemical Company, Inc. Next, a layer (film) of the photosensitive resin composition (X-1) or PSR-800 AUS410 (X-2) described above was laminated onto the layer (film) of each non-photosensitive resin composition using a vacuum laminator CVP-300 manufactured by Nikko-Materials Co., Ltd., to obtain a substrate (laminated substrate) on which each resin composition was laminated. The lamination conditions for each resin composition layer were a temperature of 80°C, a pressure of 0.2 MPa, and a pressure time of 20 seconds after evacuation for 20 seconds.

[0091] Next, a pattern forming device was used to apply 150 mJ / cm to the surface of the photosensitive resin composition layer of each laminated substrate so that circular holes with a diameter of 6 mm were formed using a circular hole pattern. ２ The laminate substrates were exposed to ultraviolet light of 1000 W at 1000 W. After exposure, each laminate substrate was left to stand at room temperature for 60 minutes. Subsequently, development was performed using an alkaline solution (1% by mass aqueous sodium carbonate solution) to form a cured product of the photosensitive resin composition. The entire surface of the patterned cured product of the photosensitive resin composition on each laminate substrate was then immersed in one of the developers shown in Table 1 at 30°C for 30 seconds for development. The developer was then wiped off, and the remaining cured product of the photosensitive resin composition was removed with hot water. The laminate substrates were then further heated at 170°C for 60 minutes to form a layer (insulating layer) of the cured product of the non-photosensitive resin composition having an opening with a diameter of 6 mm on each laminate substrate, thereby obtaining evaluation substrates for the Examples and Comparative Examples.

[0092] [Evaluation of via formability] For each evaluation board of Examples 1 to 8 and Comparative Example 1 on which a layer of a cured product of a non-photosensitive resin composition (insulating layer) was formed, the shape of the round hole formed in the insulating layer was observed at 300x magnification with an optical microscope, and the via formability was evaluated according to the following criteria. The evaluation results are shown in Table 1. ⊚: The round hole shape is extremely good with no roughness at the edges, and the via formability is excellent. ◯: The round hole shape is good and the via formability is excellent. ×: The round hole shape has widened, and curling or peeling is observed around the round hole, and the via formability is insufficient.

[0093] [Evaluation of Developability] For each evaluation substrate of Examples 1 to 8 and Comparative Example 1 on which a layer of a non-photosensitive resin composition (insulating layer) was formed, the presence or absence of residue of the resin composition (development residue) present at the bottom of the round hole formed in the insulating layer was confirmed, and the developability was evaluated according to the following criteria. The evaluation results are shown in Table 1. ○: No residue of the resin composition was found at the bottom of the 6 mm diameter round hole (substrate surface), and the developability was excellent. ×: Residue of the resin composition was found at the bottom of the 6 mm diameter round hole (substrate surface), and the developability was insufficient.

[0094] [Calculation of Dissolution Rate Ratio M] The dissolution rate A [μm / s] of the cured layer obtained by photocuring the photosensitive resin composition layer constituting each of the evaluation substrates of Examples 1 to 8 and Comparative Example 1, and the dissolution rate B [μm / s] of the non-photosensitive resin composition layer were measured according to the following procedure. First, under the same conditions as in the preparation of the evaluation substrates, the photosensitive resin composition layer and the non-photosensitive resin composition layer were laminated on different copper-clad laminates. For the photosensitive resin composition layer, 150 mJ / cm ２ The copper-clad laminates, each having a layer of photosensitive resin composition and a layer of non-photosensitive resin composition laminated thereon, were then immersed for 30 seconds in the respective developers at 30°C shown in Table 1. The thicknesses of the photosensitive resin composition layer and the non-photosensitive resin composition layer before and after immersion in the developer were measured using a laser microscope, and the dissolution rate [μm / s] for each resin composition layer was calculated. Based on the calculated dissolution rates, the ratio M (= B / A) of the dissolution rate A [μm / s] of the cured product layer of the photosensitive resin composition constituting each evaluation substrate in the Examples and Comparative Examples to the dissolution rate B of the non-photosensitive resin composition layer was calculated. The results are shown in Table 1.

[0095] The dielectric properties of the non-photosensitive resin composition layers were measured by measuring the dielectric loss tangent at 10 GHz using an ENA network analyzer (manufactured by Agilent Technologies) and a slipped post dielectric resonator (SPDR). The dielectric loss tangent of each non-photosensitive resin composition layer was confirmed to be 0.015 for Zaristo 125G, 0.013 for Non-Photosensitive Resin Composition 1, and 0.0044 for Non-Photosensitive Resin Composition 2.

[0096] From the results shown in Table 1, it can be seen that for each of the evaluation substrates of Examples 1 to 6, the ratio M (= B / A) of the dissolution rate A of the cured layer obtained by photocuring a layer of photosensitive resin composition to the dissolution rate B of the layer of non-photosensitive resin composition was 7 or more, and the formed insulating layer had excellent via-formability and developability. Furthermore, although not shown in Table 1, it was confirmed that all of the insulating layers formed on the evaluation substrates of Examples 1 to 6 had excellent (i.e., sufficiently low) dielectric properties as interlayer insulating layers. On the other hand, for the evaluation substrate of Comparative Example 1, the ratio M (= B / A) of the dissolution rate A of the cured layer obtained by photocuring a layer of photosensitive resin composition to the dissolution rate B of the layer of non-photosensitive resin composition was less than 7, and the formed insulating layer had insufficient via-formability.

Claims

1. A method for manufacturing a printed wiring board having an insulating layer, comprising the steps of: (a) laminating a substrate and a laminate such that one surface of the substrate is in contact with a surface of a layer of a non-photosensitive resin composition of the laminate; (b) a step of irradiating the layer of the photosensitive resin composition of the laminate with light in a pattern to cure the layer; (c) contacting the pattern-shaped cured layer of the photosensitive resin composition with an alkaline aqueous solution and developing the layer to form a pattern-shaped cured product of the photosensitive resin composition; (d) contacting a layer of the non-photosensitive resin composition of the laminate with an organic solvent through the cured product of the patterned photosensitive resin composition and developing the layer, thereby forming a pattern in the layer of the non-photosensitive resin composition corresponding to the pattern of the cured product of the patterned photosensitive resin composition; and (e) A step of forming the insulating layer by heating and curing the layer of the non-photosensitive resin composition on which the pattern has been formed. Including, The laminate comprises a first film, a layer of a photosensitive resin composition having solubility or swelling in an alkaline aqueous solution provided on one side of the first film, and a layer of a non-photosensitive resin composition having solubility or swelling in an organic solvent provided on the side of the photosensitive resin composition layer opposite to the side in contact with the first film, wherein a ratio M=B / A of a dissolution rate A [μm / s] in an organic solvent of a cured layer obtained by photocuring the layer of the photosensitive resin composition to a dissolution rate B [μm / s] of the layer of the non-photosensitive resin composition in an organic solvent satisfies 7≦M.

2. The method according to claim 1 , further comprising the step of: (f) removing the patterned cured product of the photosensitive resin composition.

3. The manufacturing method described in claim 1, wherein the photosensitive resin composition contains either one or both of a carboxyl group-containing resin and a hydroxyl group-containing resin.

4. The manufacturing method described in claim 1, wherein the non-photosensitive resin composition comprises a thermosetting resin.