Photosensitive resin composition, photosensitive element, printed wiring board and method for manufacturing the same

Abstract

To provide a photosensitive resin composition capable of reducing adhesion between a photosensitive layer and a protective film.SOLUTION: A photosensitive resin composition contains (A) an acid-modified vinyl group-containing resin, (B) a thermosetting resin, (C) a photopolymerizable compound, and (D) a photopolymerization initiator, wherein (A) the acid-modified vinyl group-containing resin contains (A1) an acid-modified vinyl group-containing resin including such a structure that diol having one or more alicyclic skeletons and two hydroxyl groups directly bonded to the alicyclic skeletons and a tetracarboxylic acid dianhydride are ester-bonded with each other.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a photosensitive resin composition, a photosensitive element, a printed wiring board, and a method for manufacturing the same.

Background Art

[0002] With the high performance improvement of various electronic devices, the high integration of semiconductors is progressing. Along with this, various performances are required for permanent resists (solder resists) formed on printed wiring boards, semiconductor package substrates, and the like.

[0003] As a photosensitive resin composition used for forming a solder resist, for example, a photosensitive resin composition containing an alkali-soluble resin, a photopolymerizable monomer, a photopolymerization initiator, and an epoxy compound as essential components is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The photosensitive resin composition is used, for example, in the form of a photosensitive element. The photosensitive element is used, for example, in the form of a three-layer structure in which a photosensitive layer containing the photosensitive resin composition is formed on a support film and a protective film is laminated on the photosensitive layer.

[0006] In a three-layer-structured photosensitive element, the adhesion (tack) between the photosensitive layer and the protective film is high, and problems may occur when peeling the protective film. Therefore, a photosensitive resin composition capable of reducing the adhesion between the photosensitive layer and the protective film is required.

[0007] An object of the present disclosure is to provide a photosensitive resin composition, a photosensitive element, a printed wiring board, and a method for manufacturing the same, which can reduce the adhesion between a photosensitive layer and a protective film.

Means for Solving the Problems

[0008] In order to solve the above problems, the present disclosure provides the following photosensitive resin composition, photosensitive element, printed wiring board, and method for manufacturing the same.

[0009] [1] A photosensitive resin composition containing (A) an acid-modified vinyl group-containing resin, (B) a thermosetting resin, (C) a photopolymerizable compound, and (D) a photopolymerization initiator, wherein the (A) acid-modified vinyl group-containing resin contains an acid-modified vinyl group-containing resin having a structure in which (A1) a diol having one or more alicyclic skeletons and two hydroxyl groups directly bonded to the alicyclic skeleton is ester-bonded to a tetracarboxylic dianhydride. [2] The photosensitive resin composition according to [1], further containing (E) a pigment. [3] The photosensitive resin composition according to [1] or [2], further containing (F) an inorganic filler. [4] A photosensitive element including a support film, a photosensitive layer, and a protective film in this order, wherein the photosensitive layer contains the photosensitive resin composition according to any one of [1] to [3]. [5] A printed wiring board including a permanent resist containing a cured product of the photosensitive resin composition according to any one of [1] to [3]. [6] A method for manufacturing a printed wiring board, including a step of forming a photosensitive layer on a substrate using the photosensitive resin composition according to any one of [1] to [3], a step of exposing and developing the photosensitive layer to form a resist pattern, and a step of curing the resist pattern to form a permanent resist. [7] A method for manufacturing a printed wiring board, including a step of forming a photosensitive layer on a substrate using the photosensitive element according to [4], a step of exposing and developing the photosensitive layer to form a resist pattern, and a step of curing the resist pattern to form a permanent resist.

Advantages of the Invention

[0010] According to the present disclosure, it is possible to provide a photosensitive resin composition, a photosensitive element, a printed wiring board, and a method for manufacturing the same, which can reduce the adhesion between a photosensitive layer and a protective film.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present disclosure will be described in detail. In this specification, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps as long as the intended action of that step is achieved. The term "layer" includes not only a structure formed over the entire surface when observed as a plan view but also a structure formed partially. The numerical range indicated by using "~" indicates a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described step by step in this specification, the upper limit value or the lower limit value of the numerical range at a certain step may be replaced with the upper limit value or the lower limit value of the numerical range at other steps. In the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples.

[0013] When referring to the amount of each component in a composition, unless otherwise specified, when there are multiple substances corresponding to each component in the composition, it means the total amount of the multiple substances present in the composition.

[0014] In this specification, “(meth)acrylate” means at least one of “acrylate” and the corresponding “methacrylate”, and the same applies to other similar expressions such as (meth)acrylic acid and (meth)acryloyl. In this specification, “solid content” refers to the non-volatile content excluding volatile substances (such as water and solvents) contained in the photosensitive resin composition, and also includes components that are liquid, syrup-like, or wax-like at room temperature (around 25°C).

[0015] [Photosensitive Resin Composition] The photosensitive resin composition according to this embodiment contains (A) an acid-modified vinyl group-containing resin (hereinafter also referred to as “component (A)”), (B) a thermosetting resin (hereinafter also referred to as “component (B)”), (C) a photopolymerizable compound (hereinafter also referred to as “component (C)”), and (D) a photopolymerization initiator (hereinafter also referred to as “component (D)”). The above-mentioned (A) acid-modified vinyl group-containing resin contains an acid-modified vinyl group-containing resin having a structure in which (A1) a diol having one or more alicyclic skeletons and two hydroxyl groups directly bonded to the alicyclic skeleton and a tetracarboxylic dianhydride are ester-bonded (hereinafter also referred to as “component (A1)”). The photosensitive resin composition according to this embodiment is a negative-type photosensitive resin composition, and the cured film of the photosensitive resin composition can be used as a permanent resist. Hereinafter, each component used in the photosensitive resin composition of this embodiment will be described in more detail.

[0016] ((A) Component: Acid-Modified Vinyl Group-Containing Resin) The photosensitive resin composition according to this embodiment contains an acid-modified vinyl group-containing resin as component (A). The acid-modified vinyl group-containing resin is not particularly limited as long as it has a vinyl group which is a photopolymerizable ethylenically unsaturated bond and an alkali-soluble acidic group. Examples of the acidic group possessed by the acid-modified vinyl group-containing resin include a carboxy group, a sulfo group, and a phenolic hydroxyl group. Among these, from the viewpoint of resolution, a carboxy group is preferable.

[0017] (A) component contains, as component (A1), an acid-modified vinyl group-containing resin having a structure in which a diol having one or more alicyclic skeletons and two hydroxyl groups directly bonded to the alicyclic skeleton is ester-bonded to a tetracarboxylic dianhydride. Here, since the component (A1) having the above structure does not have a methylene chain (-CH2-) between the alicyclic skeleton and the hydroxyl group, it has a highly planar and rigid structure and is easy to reduce tack. And since the photosensitive resin composition contains such a component (A1) with low tack, it is possible to reduce the adhesion between the photosensitive layer and the protective film while maintaining good resolution.

[0018] (A1) In the component, examples of the diol having one or more alicyclic skeletons and two hydroxyl groups directly bonded to the alicyclic skeleton include 2,2'-bis(4-hydroxycyclohexyl)propane, 1,4-cyclohexanediol, 1,3-cyclohexanediol, 1,2-cyclohexanediol, 1,3-cyclopentanediol, 4,4'-bicyclohexanol, etc. Among these, from the viewpoint of cover tack property, 2,2'-bis(4-hydroxycyclohexyl)propane, 1,4-cyclohexanediol, 4,4'-bicyclohexanol are preferable. These can be used alone or in combination of two or more.

[0019] In the (A1) component, examples of the tetracarboxylic dianhydride include pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 1,3,3a,4,5,9b-hexahydro-5(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)1,4-phenylene, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 4,4'-(ethyne-1,2-diyl)diphthalic anhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, dicyclohexyl-3,4,3',4'-tetracarboxylic dianhydride, 3,4'-oxydiphthalic anhydride, 4,4'-oxydiphthalic anhydride, 3,4'-biphthalic anhydride, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride, 5,5'-bis-2-norbornene-5,5',6,6'-tetracarboxylic acid-5,5',6,6'-dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, and the like. Among these, from the viewpoint of availability, pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and 4,4'-oxydiphthalic anhydride are preferred. These can be used alone or in combination of two or more.

[0020] (A1) component may be obtained by subjecting the above-described diol and the above-described tetracarboxylic dianhydride to an esterification reaction, further reacting the newly formed carboxyl group with a vinyl group-containing epoxy compound, and further reacting the newly formed hydroxyl group with an acid anhydride.

[0021] (A1) component's solid content acid value is not particularly limited. From the viewpoint of improving the solubility of the unexposed portion in an alkaline aqueous solution, the solid content acid value of (A1) component may be 30 mgKOH / g or more, 40 mgKOH / g or more, or 50 mgKOH / g or more. From the viewpoint of improving the electrical properties of the cured film, the solid content acid value of (A1) component may be 150 mgKOH / g or less, 120 mgKOH / g or less, or 100 mgKOH / g or less.

[0022] (A1) component's weight average molecular weight (Mw) is not particularly limited. From the viewpoint of improving the adhesion of the cured film, Mw of (A1) component may be 3000 or more, 4000 or more, or 5000 or more. From the viewpoint of improving the resolution of the photosensitive layer, Mw of (A1) component may be 30000 or less, 25000 or less, or 18000 or less. Mw can be measured by gel permeation chromatography (GPC) method.

[0023] (A1) component may contain other acid-modified vinyl group-containing resins that do not correspond to the above (A1) component. Examples of other acid-modified vinyl group-containing resins include acid-modified vinyl group-containing epoxy resins and acid-modified vinyl group-containing phenolic resins.

[0024] (A1) component's solid content acid value is not particularly limited. From the viewpoint of improving the solubility of the unexposed portion in an alkaline aqueous solution, the solid content acid value of (A1) component may be 30 mgKOH / g or more, 40 mgKOH / g or more, or 50 mgKOH / g or more. From the viewpoint of improving the electrical properties of the cured film, the solid content acid value of (A1) component may be 150 mgKOH / g or less, 120 mgKOH / g or less, or 100 mgKOH / g or less.

[0025] The weight average molecular weight (Mw) of the other acid-modified vinyl group-containing resin is not particularly limited. From the viewpoint of improving the adhesion of the cured film, the Mw of the other acid-modified vinyl group-containing resin may be 3,000 or more, 4,000 or more, or 5,000 or more. From the viewpoint of improving the resolution of the photosensitive layer, the Mw of the other acid-modified vinyl group-containing resin may be 30,000 or less, 25,000 or less, or 18,000 or less. Mw can be measured by gel permeation chromatography (GPC) method.

[0026] The content of the (A1) component in the (A) component is preferably 4 to 100% by mass, more preferably 15 to 100% by mass, and still more preferably 25 to 100% by mass based on the total solid content of the (A) component. When this content is 4% by mass or more, the adhesion between the photosensitive layer and the protective film can be more sufficiently reduced.

[0027] The content of the (A) component in the photosensitive resin composition may be 20 to 70% by mass, 25 to 60% by mass, 30 to 50% by mass, or 32 to 45% by mass based on the total solid content of the photosensitive resin composition from the viewpoints of improving the heat resistance, electrical properties, and chemical resistance of the permanent resist.

[0028] ((B) component: thermosetting resin) The photosensitive resin composition according to this embodiment contains a thermosetting resin as the (B) component. By using the (B) component, the heat resistance, adhesiveness, chemical resistance, etc. of the cured film (permanent resist) formed from the photosensitive resin composition can be improved. The (B) component may be used alone or in combination of two or more.

[0029] Examples of the (B) component include epoxy resins, phenolic resins, unsaturated imide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, and melamine resins.

[0030] Examples of the epoxy resin 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, novolac type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, hydantoin type epoxy resin, triglycidyl isocyanurate, and bixylenol type epoxy resin.

[0031] The content of component (B) may be 2 to 30% by mass, 5 to 25% by mass, or 8 to 20% by mass based on the total solid content of the photosensitive resin composition. When the content of component (B) is within the above range, the heat resistance of the cured film formed can be further improved while maintaining good developability.

[0032] ((C) component: photopolymerizable compound) The photosensitive resin composition according to this embodiment contains a photopolymerizable compound as component (C) from the viewpoint of enhancing the chemical resistance after exposure and increasing the difference in developability resistance between the exposed portion and the unexposed portion. Component (C) may be any photopolymerizable compound having an ethylenically unsaturated group and no acidic group, and is not particularly limited.

[0033] Examples of component (C) include photopolymerizable compounds having one ethylenically unsaturated group, photopolymerizable compounds having two ethylenically unsaturated groups, and photopolymerizable compounds having three or more ethylenically unsaturated groups.

[0034] Examples of the photopolymerizable compound having one ethylenically unsaturated group include (meth)acrylic acid and (meth)acrylic acid alkyl esters. Examples of the (meth)acrylic acid alkyl ester include (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid butyl ester, (meth)acrylic acid 2-ethylhexyl ester, and (meth)acrylic acid hydroxyethyl ester.

[0035] Examples of the photopolymerizable compound having two ethylenically unsaturated groups include polyethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2-bis(4-(meth)acryloxypolyethoxypolypropoxyphenyl)propane, and bisphenol A diglycidyl ether di(meth)acrylate.

[0036] Examples of the photopolymerizable compound having three or more ethylenically unsaturated groups include (meth)acrylate compounds having a skeleton derived from trimethylolpropane such as trimethylolpropane tri(meth)acrylate; (meth)acrylate compounds having a skeleton derived from tetramethylolmethane such as tetramethylolmethane tri(meth)acrylate and tetramethylolmethane tetra(meth)acrylate; (meth)acrylate compounds having a skeleton derived from pentaerythritol such as pentaerythritol tri(meth)acrylate and pentaerythritol tetra(meth)acrylate; (meth)acrylate compounds having a skeleton derived from dipentaerythritol such as dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate; (meth)acrylate compounds having a skeleton derived from ditrimethylolpropane such as ditrimethylolpropane tetra(meth)acrylate; and (meth)acrylate compounds having a skeleton derived from diglycerin.

[0037] Among these, from the viewpoint of enhancing the chemical resistance after exposure and increasing the difference in the developability between the exposed portion and the unexposed portion, (meth)acrylate compounds having a skeleton derived from dipentaerythritol are preferred, and dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate are more preferred.

[0038] The content of the component (C) may be 1 to 20% by mass, 2 to 15% by mass, or 4 to 12% by mass based on the total solid content of the photosensitive resin composition.

[0039] ((D) Component: Photoinitiator) (D) The photoinitiator as the component is not particularly limited as long as it can polymerize the (A) component or the (C) component. The (D) component may be used alone or in combination of two or more.

[0040] (D) components include, for example, benzoin compounds such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acetophenone compounds such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, and N,N-dimethylaminoacetophenone; anthraquinone compounds such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; ketal compounds such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenone compounds such as benzophenone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis(diethylamino)benzophenone, Michler's ketone, and 4-benzoyl-4'-methyldiphenyl sulfide; imidazole compounds such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer, 2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer, and 2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide;Oxime ester compounds such as 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetoxime), 1-phenyl-1,2-propanedione-2-[O-(ethoxycarbonyl)oxime]; and tertiary amine compounds such as ethyl N,N-dimethylaminobenzoate, isoamyl N,N-dimethylaminobenzoate, pentyl 4-dimethylaminobenzoate, triethylamine, and triethanolamine.

[0041] The content of component (D) in the photosensitive resin composition is not particularly limited, but may be 0.1 to 15% by mass, 0.15 to 10% by mass, or 0.2 to 5% by mass based on the total solid content of the photosensitive resin composition.

[0042] ((E) component: pigment) The photosensitive resin composition of the present embodiment may further contain a pigment as the (E) component from the viewpoint of improving the discriminability or appearance of the manufacturing apparatus. As the (E) component, a colorant that develops a desired color when concealing wiring or the like can be used. Examples of the (E) component include phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black.

[0043] The content of the (E) component may be 0.1 to 10% by mass, 0.15 to 8% by mass, or 0.2 to 5% by mass based on the total solid content in the photosensitive resin composition from the viewpoint of further concealing the wiring.

[0044] ((F) component: inorganic filler) The photosensitive resin composition according to the present embodiment may further contain an inorganic filler as the (F) component. By containing the (F) component, the adhesive strength, reliability, etc. of the permanent resist can be improved. The (F) component may be used alone or in combination of two or more.

[0045] Examples of the inorganic filler include silica, alumina, titania, tantalum oxide, zirconia, silicon nitride, barium titanate, barium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, lead titanate, lead zirconate titanate, lead lanthanum zirconate titanate, gallium oxide, spinel, mullite, cordierite, talc, aluminum titanate, yttria-containing zirconia, barium silicate, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, zinc oxide, magnesium titanate, hydrotalcite, mica, fired kaolin, and carbon.

[0046] (F) component may contain silica from the viewpoint of improving the heat resistance of the permanent resist, and may contain barium sulfate from the viewpoints of improving the heat resistance and adhesive strength of the permanent resist. From the viewpoint of improving the dispersibility of the inorganic filler, an inorganic filler surface-treated in advance with alumina or an organic silane compound may be used.

[0047] The average particle size of the inorganic filler may be 0.01 μm or more, 0.1 μm or more, 0.2 μm or more, or 0.3 μm or more, and may be 5.0 μm or less, 3.0 μm or less, 2.0 μm or less, or 1.5 μm or less.

[0048] (F) The content of the component may be 5 to 70% by mass, 6 to 60% by mass, or 10 to 50% by mass based on the total solid content of the photosensitive resin composition. When the content of the (F) component is within the above range, the low coefficient of thermal expansion, heat resistance, film strength, etc. can be further improved.

[0049] ((G) component: elastomer) The photosensitive resin composition according to this embodiment may further contain an elastomer as the (G) component. By containing the (G) component, it is possible to suppress a decrease in flexibility and adhesive strength caused by distortion (internal stress) inside the resin due to the curing shrinkage of the (A) component. The (G) component may be used alone or in combination of two or more.

[0050] Examples of the component (G) include styrenic elastomers, olefinic elastomers, urethane elastomers, polyester elastomers, polyamide elastomers, acrylic elastomers, and silicone elastomers. These elastomers are composed of a hard segment component that contributes to heat resistance and strength, and a soft segment component that contributes to flexibility and toughness.

[0051] Examples of styrenic elastomers include styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-ethylene-butylene-styrene block copolymers, and styrene-ethylene-propylene-styrene block copolymers. As components constituting styrenic elastomers, in addition to styrene, styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, and 4-cyclohexylstyrene can be used.

[0052] Examples of olefinic elastomers include ethylene-propylene copolymers, ethylene-α-olefin copolymers, ethylene-α-olefin-non-conjugated diene copolymers, propylene-α-olefin copolymers, butene-α-olefin copolymers, ethylene-propylene-diene copolymers, dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene, copolymers of non-conjugated dienes such as butadiene and isoprene with α-olefins, and carboxylic acid-modified butadiene-acrylonitrile copolymers.

[0053] As urethane elastomers, compounds composed of a hard segment consisting of a low molecular weight (short chain) diol and a diisocyanate, and a soft segment consisting of a high molecular weight (long chain) diol and a diisocyanate can be used.

[0054] Examples of the short-chain diol include ethylene glycol, propylene glycol, 1,4-butanediol, and bisphenol A. The number average molecular weight of the short-chain diol is preferably 48 to 500.

[0055] Examples of the long-chain diol include polypropylene glycol, polytetramethylene oxide, poly(1,4-butylene adipate), poly(ethylene-1,4-butylene adipate), polycaprolactone, poly(1,6-hexylene carbonate), and poly(1,6-hexylene-neopentylene adipate). The number average molecular weight of the long-chain diol is preferably 500 to 10,000.

[0056] As the polyester-based elastomer, a compound obtained by polycondensing a dicarboxylic acid or its derivative and a diol compound or its derivative can be used.

[0057] Examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid, and dodecanedicarboxylic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. The dicarboxylic acid can be used alone or in combination of two or more.

[0058] Examples of the diol compound include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,10-decanediol; alicyclic diols such as 1,4-cyclohexanediol; and aromatic diols such as bisphenol A, bis-(4-hydroxyphenyl)methane, bis-(4-hydroxy-3-methylphenyl)propane, and resorcinol.

[0059] As the polyester-based elastomer, a multi-block copolymer in which an aromatic polyester (for example, polybutylene terephthalate) is used as the hard segment component and an aliphatic polyester (for example, polytetramethylene glycol) is used as the soft segment component can be used. There are various grades of polyester-based elastomers depending on the types, ratios, and molecular weights of the hard segment and the soft segment.

[0060] Polyamide-based elastomers are roughly classified into two types: a polyether block amide type and a polyether ester block amide type, in which polyamide is used for the hard segment and polyether or polyester is used for the soft segment. Examples of the polyamide include polyamide-6, polyamide-11, and polyamide-12. Examples of the polyether include polyoxyethylene glycol, polyoxypropylene glycol, and polytetramethylene glycol.

[0061] As the acrylic-based elastomer, a compound containing a structural unit based on a (meth)acrylate ester as a main component can be used. Examples of the (meth)acrylate ester include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, methoxyethyl (meth)acrylate, and ethoxyethyl (meth)acrylate. The acrylic-based elastomer may be a compound obtained by copolymerizing a (meth)acrylate ester and acrylonitrile, or may be a compound obtained by further copolymerizing a monomer having a functional group serving as a crosslinking point. Examples of the monomer having a functional group include methyl methacrylate, glycidyl methacrylate, and allyl glycidyl ether.

[0062] Examples of the acrylic elastomer include acrylonitrile-butyl acrylate copolymer, acrylonitrile-butyl acrylate-ethyl acrylate copolymer, methyl methacrylate-butyl acrylate-methacrylic acid copolymer, and acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer. As the acrylic elastomer, acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer or methyl methacrylate-butyl acrylate-methacrylic acid copolymer is preferable, and methyl methacrylate-butyl acrylate-methacrylic acid copolymer is more preferable.

[0063] The silicone elastomer is a compound mainly composed of organopolysiloxane. Examples of the organopolysiloxane include polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane. The silicone elastomer may be a compound obtained by modifying a part of the organopolysiloxane with a vinyl group, an alkoxy group or the like.

[0064] (G) component may contain a carboxylic acid-modified butadiene-acrylonitrile copolymer or a polyester elastomer having a hydroxyl group from the viewpoint of improving the adhesion of the cured film.

[0065] The content of the (G) component may be 2 to 50 parts by mass, 4 to 45 parts by mass, 6 to 40 parts by mass, or 10 to 35 parts by mass with respect to 100 parts by mass of the (A) component. When the content of the (G) component is within the above range, the elastic modulus of the cured film in the high temperature region becomes low, and the unexposed portion is more easily eluted with the developer.

[0066] (Other components) The photosensitive resin composition according to this embodiment may further contain various additives as necessary. Examples of the additives include polymerization inhibitors such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; thickeners such as benton and montmorillonite; antifoaming agents of silicone-based, fluorine-based, and vinyl resin-based; silane coupling agents; and flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, antimony compounds, phosphate compounds, aromatic condensed phosphoric acid esters, and halogen-containing condensed phosphoric acid esters.

[0067] (Solvent) The photosensitive resin composition according to this embodiment contains a solvent for dissolving and dispersing each component, thereby facilitating coating on a substrate and forming a coating film with a uniform thickness.

[0068] Examples of the solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. The solvent may be used alone or in combination of two or more.

[0069] The blending amount of the solvent is not particularly limited, but the proportion of the solvent in the photosensitive resin composition may be 10 to 50% by mass, 20 to 40% by mass, or 25 to 35% by mass.

[0070] The photosensitive resin composition of this embodiment can be prepared by uniformly mixing the above-described components with a roll mill, a bead mill, or the like.

[0071] [Photosensitive Element] The photosensitive element according to this embodiment includes a support film, a photosensitive layer containing the above-described photosensitive resin composition, and a protective film. FIG. 1 is a cross-sectional view schematically showing the photosensitive element according to this embodiment. As shown in FIG. 1, the photosensitive element 1 includes a support film 10, a photosensitive layer 20 formed on the support film 10, and a protective film 30 laminated on the photosensitive layer.

[0072] The photosensitive element 1 can be produced by applying the photosensitive resin composition according to this embodiment on the support film 10 by a known method such as reverse roll coating, gravure roll coating, comma coating, curtain coating, etc., and then drying the coating film to form the photosensitive layer 20.

[0073] Examples of the support film include polyester films such as polyethylene terephthalate and polybutylene terephthalate; and polyolefin films such as polypropylene and polyethylene. The thickness of the support film may be, for example, 5 to 100 μm. The thickness of the photosensitive layer may be, for example, 5 to 50 μm, 5 to 40 μm, or 10 to 30 μm. The surface roughness of the support film is not particularly limited, but the arithmetic mean roughness (Ra) may be 1000 nm or less, 500 nm or less, or 250 nm or less.

[0074] For drying the coating film, hot air drying, drying using far-infrared or near-infrared rays can be used. The drying temperature may be 60 to 120 °C, 70 to 110 °C, or 80 to 100 °C. The drying time may be 1 to 60 minutes, 2 to 30 minutes, or 5 to 20 minutes.

[0075] On the photosensitive layer 20, a protective film 30 covering the photosensitive layer 20 is further provided. As the protective film 30, for example, a polymer film such as polyethylene or polypropylene may be used.

[0076] According to the photosensitive element of the present embodiment, since the photosensitive layer 20 contains the photosensitive resin composition described above, the adhesion (tack) between the photosensitive layer 20 and the protective film 30 can be reduced, and problems when peeling the protective film 30 from the photosensitive layer 20 can be suppressed.

[0077] [Printed Wiring Board] The printed wiring board according to the present embodiment includes a permanent resist containing a cured product of the photosensitive resin composition according to the present embodiment.

[0078] The manufacturing method of the printed wiring board according to the present embodiment includes a step of forming a photosensitive layer on a substrate using a photosensitive element, a step of exposing and developing the photosensitive layer to form a resist pattern, and a step of curing the resist pattern to form a permanent resist. Hereinafter, an example of each step will be described.

[0079] First, prepare a substrate such as a copper-clad laminate, and form a photosensitive layer on the substrate. The photosensitive layer may be formed by peeling the protective film from the photosensitive element on the substrate and laminating the photosensitive layer. As a method of laminating the photosensitive layer, for example, a method of thermal lamination using a laminator can be mentioned.

[0080] Next, bring a negative film into direct contact with the photosensitive layer or contact it through a support film, and irradiate with actinic rays for exposure. Examples of the actinic rays include electron beams, ultraviolet rays, and X-rays, and ultraviolet rays are preferable. As the light source, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a halogen lamp, etc. can be used. The exposure amount may be 10~2000mJ / cm 2 , 100~1500mJ / cm 2 , or 300~1000mJ / cm 2 .

[0081] After exposure, the unexposed portion is removed with a developer to form a resist pattern. Examples of the developing method include a dipping method and a spray method. As the developer, for example, an alkaline aqueous solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, or tetramethylammonium hydroxide can be used.

[0082] By performing at least one of post-exposure and post-heating on the resist pattern, a pattern hardening film (permanent resist) can be formed. The exposure amount of the post-exposure is 100~5000 mJ / cm 2 500~2000 mJ / cm 2 or 700~1500 J / cm 2 may be sufficient. The heating temperature of the post-heating may be 100~200 °C, 120~180 °C, or 135~165 °C. The heating time of the post-heating may be 5 minutes to 12 hours, 10 minutes to 6 hours, or 30 minutes to 2 hours.

[0083] The permanent resist according to this embodiment can be used as an interlayer insulating layer or a surface protection layer of a semiconductor element. A semiconductor element including an interlayer insulating layer or a surface protection layer formed from the cured film of the above-described photosensitive resin composition, and an electronic device including the semiconductor element can be manufactured. The semiconductor element may be, for example, a memory, a package, etc. having a multilayer wiring structure, a rewiring structure, etc. Examples of the electronic device include a mobile phone, a smartphone, a tablet terminal, a personal computer, and a hard disk suspension. By providing a pattern hardening film formed by the photosensitive resin composition according to this embodiment, a semiconductor element and an electronic device with excellent reliability can be provided.

Examples

[0084] Hereinafter, the present disclosure will be described more specifically by way of examples, but the present disclosure is not limited to these examples.

[0085] <Measurement method of FT-IR spectrum> FT-IR was measured using an infrared spectrophotometer (manufactured by PerkinElmer Japan, product name: Frontier).

[0086] <Measurement method of weight average molecular weight (Mw)> As a sample for Mw measurement, a solution containing (A) an acid-modified vinyl group-containing resin was dissolved in tetrahydrofuran (THF) to prepare a 0.2 mass% THF solution. Mw was measured by gel permeation chromatography (GPC) method and derived by converting using a calibration curve of standard polystyrene. The conditions of GPC are shown below. Measuring device: Shodex (registered trademark) GPC-101 (manufactured by Showa Denko K.K.) Detector: Differential refractometer Shodex RI-71S (manufactured by Showa Denko K.K.) Column: Shodex LF-804 + LF-804 (manufactured by Showa Denko K.K.) Column temperature: 40 °C Eluent: Tetrahydrofuran (THF) Flow rate: 1 mL / min

[0087] <Measurement method of acid value> The resin acid value is the acid value of the binder polymer solution measured using a mixed indicator of bromothymol blue and phenol red according to JIS K6901 5.3.2. The resin acid value means the number of mg of potassium hydroxide required to neutralize the acidic components contained in 1 g of the binder polymer solution. The solid content acid value is the value calculated by the following formula. Solid content acid value = 100 × resin acid value / (solid content concentration (mass%) of the binder polymer solution)

[0088] [Synthesis Example 1] Into a flask equipped with a stirring device, a dropping funnel, a condenser, a thermometer, and a gas introduction tube, 109.1 g of pyromellitic dianhydride (manufactured by Kanto Chemical Co., Inc.), 153.3 g of 2,2'-bis(4-hydroxycyclohexyl)propane (manufactured by Maruzen Petrochemical Co., Ltd., H-BPA, a diol having one or more alicyclic skeletons and two hydroxyl groups directly bonded to the alicyclic skeleton), 0.8 g of triphenylphosphine as a catalyst, and 317.9 g of propylene glycol monomethyl ether acetate as a solvent were added. While stirring and replacing the gas in the flask with nitrogen gas, the temperature was raised to 110°C and reacted for 1 hour, and it was confirmed by FT-IR that the absorption of the acid anhydride group had disappeared. As a result, a carboxyl group-containing polyester resin having a weight average molecular weight of 4000 and a resin acid value of 140.0 mgKOH / g was obtained. The FT-IR spectrum of the obtained carboxyl group-containing polyester resin is shown in Figure 2.

[0089] Next, the gas in the flask was replaced with air, and 196.2 g of 3,4-epoxycyclohexylmethyl methacrylate (manufactured by Sankyo Chemical Co., Ltd., TTA15) and 0.8 g of 2,6-di-tert-butyl-4-cresol as a polymerization inhibitor were added to the obtained carboxyl group-containing polyester resin. After raising the temperature to 120°C and reacting for 4 hours, it was cooled to 110°C. As a result, a photosensitive polyester resin having a weight average molecular weight of 6500 and a resin acid value of 24.4 mgKOH / g was obtained.

[0090] Next, 60.0 g of succinic anhydride (manufactured by Shin Nippon Rika Co., Ltd., trade name "Ricasid SA") was added to the obtained photosensitive polyester resin, and the reaction was carried out at 110°C for 9 hours, and it was confirmed by FT-IR that the absorption of the acid anhydride group had disappeared. As a result, a carboxyl group-containing photosensitive polyester resin (acid-modified vinyl group-containing resin) (a-1) having a weight average molecular weight of 9800, a resin acid value of 63.3 mgKOH / g, a solid content acid value of 98.3 mgKOH / g, and a double bond equivalent of 520 g / mol was obtained. The FT-IR spectrum of the obtained carboxyl group-containing photosensitive polyester resin (a-1) is shown in Figure 3.

[0091] [Synthesis Example 2] Into a flask equipped with a stirring device, a dropping funnel, a condenser, a thermometer, and a gas introduction tube, 147.1 g of 3,3’,4,4’-biphenyltetracarboxylic dianhydride (manufactured by JFE Chemical Corporation, BPDA), 165.9 g of 2,2’-bis(4-hydroxycyclohexyl)propane (manufactured by Maruzen Petrochemical Co., Ltd., H-BPA, a diol having one or more alicyclic skeletons and two hydroxyl groups directly bonded to the alicyclic skeleton), 0.9 g of triphenylphosphine as a catalyst, and 354.2 g of propylene glycol monomethyl ether acetate as a solvent were added. While stirring and replacing the gas in the flask with nitrogen gas, the temperature was raised to 140 °C and reacted for 6 hours, and then cooled to 110 °C. Next, the gas in the flask was replaced with air, 13.0 g of 2-hydroxyethyl methacrylate (HEMA) and 0.9 g of 2,6-di-tert-butyl-4-cresol as a polymerization inhibitor were added, and the reaction was carried out at 110 °C for 2 hours. It was confirmed by FT-IR that the absorption of the acid anhydride group had disappeared. As a result, a carboxyl group-containing polyester resin having a weight average molecular weight of 4200 and a resin acid value of 92.8 mgKOH / g was obtained. The FT-IR spectrum of the obtained carboxyl group-containing polyester resin is shown in Figure 4.

[0092] Next, 137.9 g of glycidyl methacrylate (manufactured by Mitsubishi Gas Chemical Company, Inc., GMA) was added to the obtained carboxyl group-containing polyester resin, the temperature was raised to 120 °C and reacted for 5 hours, and then cooled to 110 °C. As a result, a photosensitive polyester resin having a weight average molecular weight of 8800 and a resin acid value of 8.6 mgKOH / g was obtained.

[0093] Next, 114.1 g of succinic anhydride (manufactured by Shin Nippon Rika Kogyo Co., Ltd., trade name "Rikacid SA") was added to the obtained photosensitive polyester resin, and the mixture was reacted at 110 °C for 5 hours. It was confirmed by FT-IR that the absorption of the acid anhydride group had disappeared. As a result, a carboxyl group-containing photosensitive polyester resin (acid-modified vinyl group-containing resin) (a-2) having a weight average molecular weight of 10,000, a resin acid value of 76.3 mgKOH / g, a solid content acid value of 118.3 mgKOH / g, and a double bond equivalent of 540 g / mol was obtained. The FT-IR spectrum of the obtained carboxyl group-containing photosensitive polyester resin (a-2) is shown in FIG. 5.

[0094] [Synthesis Examples 3 to 12] Carboxyl group-containing photosensitive polyester resins (acid-modified vinyl group-containing resins) (a-3) to (a-12) were obtained in the same manner as in Synthesis Example 2, except that the types and amounts (unit: g) of the tetracarboxylic dianhydride, diol, end-capping agent, epoxy compound, and acid anhydride used were changed as shown in Table 1.

[0095] [Synthesis Example 13] 350 parts by mass of bisphenol F novolak type epoxy resin (manufactured by DIC Corporation, trade name "EXA-7376"), 70 parts by mass of acrylic acid, 0.5 parts by mass of methylhydroquinone, and 120 parts by mass of carbitol acetate were mixed while stirring at 90 °C. The mixed solution was cooled to 60 °C, 2 parts by mass of triphenylphosphine was added, and the reaction was carried out at 100 °C until the acid value of the solution reached 1 mgKOH / g or less. 98 parts by mass of tetrahydrophthalic anhydride and 850 parts by mass of carbitol acetate were added to the reaction solution, and the reaction was carried out at 80 °C for 6 hours. Thereafter, the reaction solution was cooled to room temperature to obtain a solution of an acid-modified vinyl group-containing resin (a-13) as component (A) (solid content concentration: 73 mass%).

[0096]

Table 1

[0097] Each symbol in Table 1 represents the following compound. PMDA: Pyromellitic dianhydride (manufactured by Kanto Chemical) BPDA: 3,3’,4,4’-Biphenyltetracarboxylic dianhydride (manufactured by JFE Chemical Corporation) ODPA: 4,4’-Oxydiphthalic anhydride (manufactured by MANAC Co., Ltd.) H-BPA: 2,2’-Bis(4-hydroxycyclohexyl)propane (secondary alcohol) (manufactured by Maruzen Petrochemical Co., Ltd.) CHD: 1,4-Cyclohexanediol (secondary alcohol) (manufactured by Tokyo Chemical Industry Co., Ltd.) CHDM: 1,4-Cyclohexanedimethanol (primary alcohol) (manufactured by Tokyo Chemical Industry Co., Ltd.) TCDDM: Tricyclo[5.2.1.02,6]decane dimethanol (primary alcohol) (manufactured by Tokyo Chemical Industry Co., Ltd.) HEMA: 2-Hydroxyethyl methacrylate (manufactured by Nippon Shokubai Co., Ltd.) TTA15: 3,4-Epoxycyclohexylmethyl methacrylate (manufactured by Sankyo Chemical Co., Ltd.) GMA: Glycidyl methacrylate (manufactured by Mitsubishi Gas Chemical Company, Inc.) SA: Succinic anhydride (manufactured by Shin Nippon Rika Co., Ltd., trade name “Rikacid SA”) THPA: Tetrahydrophthalic anhydride (manufactured by Shin Nippon Rika Co., Ltd., trade name “Rikacid TH”)

[0098] [Examples 1 to 8 and Comparative Examples 1 to 6] [Preparation of Photosensitive Resin Composition] Each material shown in Table 2 was mixed in the blending amounts (unit: parts by mass) shown in the same table and kneaded with a three-roll mill to prepare a photosensitive resin composition. In each example, carbitol acetate was appropriately added to adjust the concentration, and photosensitive resin compositions of Examples 1 to 8 and Comparative Examples 1 to 6 with a solid content concentration of 60% by mass were obtained. The blending amounts (parts by mass) shown in Table 2 are the masses of the non-volatile components (solid contents). Details of each component shown in Table 2 are as follows.

[0099] [Component (A)] a-1 to a-13: Acid-modified vinyl group-containing resins (a-1) to (a-13) obtained in Synthesis Examples 1 to 13 a-14: An acid-modified vinyl group-containing resin (a-14) (weight average molecular weight 8900, resin acid value 57.6 mgKOH / g) obtained by subjecting an oxirane adduct of a 2,6-dimethylphenol·4,4'-(propane-2,2-diyl)diphenol·formaldehyde polycondensate to an addition reaction with acrylic acid and tetrahydrophthalic anhydride (Component (B)) YX4000X: A biphenyl-type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name) (Component (C)) DPHA: Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name) (Component (D)) Acetophenones: 2-Methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone Thioxanthones: 2,4-Diethylthioxanthone (Component (E)) Phthalocyanine-based pigment: Phthalocyanine-based pigment (manufactured by Sanyo Shikiso Co., Ltd.) (Component (F)) Silica: Manufactured by Denka Co., Ltd., trade name "SFP-20M", average particle diameter 0.3 μm

[0100] (Preparation of photosensitive element) A polyethylene terephthalate film with a thickness of 25 μm (manufactured by Teijin Limited, trade name "G2-25") was used as a support film. On this support film, the photosensitive resin composition prepared in each example was applied so that the film thickness after drying would be 25 μm, and it was dried at 100 °C for 10 minutes using a hot air convection dryer to form a photosensitive layer. Subsequently, a biaxially stretched polypropylene film (manufactured by Oji Flex Co., Ltd., trade name "MA-411") was laminated as a protective film on the surface opposite to the side in contact with the support film of the photosensitive layer, and a photosensitive element having a laminated structure of a support film, a photosensitive layer, and a protective film was produced. Using the produced photosensitive element, the following evaluations were conducted. The results are shown in Table 2.

[0101] [Evaluation of Adhesion (Cover Tack Property)] The photosensitive elements obtained in the examples and comparative examples were cut into a size of 20 mm × 120 mm, and the peeling strength of the protective film from the photosensitive layer was measured at 50 mm under the conditions of an angle of 180 degrees and a speed of 300 mm / min at 23°C. Based on the measurement results, the cover tack property was evaluated according to the following criteria. The results are shown in Table 2. A: The maximum stress is less than 0.02 N / mm B: The maximum stress is 0.02 N / mm or more and less than 0.06 N / mm C: The maximum stress is 0.06 N / mm or more

[0102] [Evaluation of Resolution] [Preparation of Evaluation Laminated Body] The copper foil surface of a printed wiring board substrate (manufactured by Resonac Co., Ltd., trade name "MCL-E-679") obtained by laminating a 12-μm-thick copper foil on a glass epoxy substrate was treated with a roughening treatment solution (manufactured by Meck Co., Ltd., trade name "CZ-8100"), followed by washing with water and drying to obtain a roughened printed wiring board substrate. Next, the protective film was peeled off from the photosensitive elements manufactured in each example and comparative example, and the exposed photosensitive layer was placed in contact with the copper foil of the above roughened printed wiring board substrate. Then, a laminating treatment was performed using a press-type vacuum laminator (manufactured by Naiki Seisakusho Co., Ltd., trade name "MVLP-500"). The laminating conditions were a press hot plate temperature of 70°C, a vacuum drawing time of 20 seconds, a laminating press time of 30 seconds, an air pressure of 4 kPa or less, and a crimping pressure of 0.4 MPa. After the laminating treatment, it was left at room temperature for 1 hour or more to obtain an evaluation laminated body in which the photosensitive layer and the support film were laminated in this order on the copper foil surface of the printed wiring board substrate.

[0103] [Measurement of Sensitivity of Photosensitive Layer] After peeling off and removing the support film from the laminate for evaluation, a 41-step tablet was placed on the photosensitive layer, and exposure was performed using a direct imaging exposure apparatus "DXP-3512" (manufactured by Okou Seisakusho Co., Ltd.) with an ultra-high pressure mercury lamp as the light source. The exposure pattern used was a pattern in which dots were arranged in a grid (dot diameter: distance between dot centers = 1:2). The dot diameter (φ) was changed in 10-μm increments within the range of 30 to 200 μm. After exposure, the sample was left at room temperature for 30 minutes, and then the photosensitive layer of the unexposed portion was spray-developed using a 1 mass% aqueous sodium carbonate solution at 30°C. After development, the exposure energy amount at which the number of remaining step levels of the gloss of the 41-step tablet became 10 was defined as the sensitivity of the photosensitive layer (unit: mJ / cm 2 2). Using the pattern exposed at this sensitivity, the resolution of the vias provided in the photosensitive layer was evaluated according to the following evaluation criteria.

[0104] (Evaluation of Via Resolution) For the evaluation of via resolution, the photosensitive layer was exposed with the sensitivity of the photosensitive layer measured above, that is, the exposure energy amount at which the number of remaining step levels became 10, and then spray-developed. After that, the via pattern was observed using an optical microscope and evaluated according to the following criteria. The following state of "opening" refers to a state in which the copper foil of the base material for printed wiring boards can be confirmed when observing the via portion of the dot pattern using an optical microscope. A judgment of "A" indicates good characteristics. A: The via portion of the φ60-μm dot pattern is open. B: The via portion of the φ60-μm dot pattern is not open, but the via portion of the φ70-μm dot pattern is open.

[0105] [Table 2] [Explanation of Symbols]

[0106] 1... photosensitive element, 10... support film, 20... photosensitive layer, 30... protective film.

Claims

1. A photosensitive resin composition containing (A) an acid-modified vinyl group-containing resin, (B) a thermosetting resin, (C) a photopolymerizable compound, and (D) a photoinitiator, wherein the (A) acid-modified vinyl group-containing resin is a photosensitive resin composition containing (A1) an acid-modified vinyl group-containing resin having a structure in which a diol having one or more alicyclic skeletons and two hydroxyl groups directly bonded to the alicyclic skeleton is ester-bonded to a tetracarboxylic dianhydride.

2. The photosensitive resin composition according to claim 1, further containing (E) a pigment.

3. The photosensitive resin composition according to claim 1, further containing (F) an inorganic filler.

4. A photosensitive element comprising a support film, a photosensitive layer, and a protective film in this order, wherein the photosensitive layer contains the photosensitive resin composition according to any one of claims 1 to 3.

5. A printed wiring board comprising a permanent resist containing a cured product of the photosensitive resin composition according to any one of claims 1 to 3.

6. A step of forming a photosensitive layer on a substrate using the photosensitive resin composition according to any one of claims 1 to 3, a step of exposing and developing the photosensitive layer to form a resist pattern, a step of curing the resist pattern to form a permanent resist, and a method for manufacturing a printed wiring board comprising the above steps.

7. A step of forming a photosensitive layer on a substrate using the photosensitive element according to claim 4, a step of exposing and developing the photosensitive layer to form a resist pattern, a step of curing the resist pattern to form a permanent resist, and a method for manufacturing a printed wiring board comprising the above steps.

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