Photosensitive resin composition, dry film, cured product, and printed wiring board

Abstract

To provide a photosensitive resin composition that contains a carboxyl group-containing resin and gives a cured product, which easily gets a low dielectric loss tangent and keeps flexibility, and is less susceptible to excessive corrosion even when treated with an oxidizing agent.SOLUTION: A photosensitive resin composition contains a carboxyl group-containing resin (A), a photopolymerization initiator (B), a photopolymerizable compound (C), an epoxy compound (D), 50 mass% or more and 300 mass% or less of silica (E) relative to the carboxyl group-containing resin (A), and 21 mass% or more and 100 mass% or less of a blocked isocyanate compound (F) relative to the carboxyl group-containing resin (A).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a photosensitive resin composition, a dry film, a cured product, and a printed wiring board, and more particularly to a photosensitive resin composition containing a carboxyl group-containing resin, a dry film containing this photosensitive resin composition, a cured product of this photosensitive resin composition, and a printed wiring board provided with a solder resist layer or an interlayer insulating layer containing this cured product. [Background technology]

[0002] Patent Document 1 discloses a curable resin composition that produces a cured product with a low dielectric constant and a low dielectric loss tangent. Patent Document 1 also discloses that the curable resin composition contains an alkali-soluble resin, an inorganic filler, a photocurable compound that does not have a hydroxyl group or a carboxyl group, an adhesion promoter, and a photopolymerization initiator, that a blocked isocyanate is preferred as the adhesion promoter, and that the amount of the adhesion promoter is 0.01 to 20 parts by mass, calculated as solid content, per 100 parts by mass of the alkali-soluble resin (A). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-68242 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the findings independently obtained by the inventors through research and development, when a solder resist layer, an interlayer insulating layer, etc., is produced from a cured product of a resin composition containing a carboxyl group-containing resin, if an inorganic filler is blended to reduce the dielectric loss tangent, the cured product is likely to become brittle. Furthermore, when the surface of the cured product is treated with an oxidizing agent or the like to adjust the roughness in order to improve the adhesion between the cured product, particularly the interlayer insulating layer, and the conductor that overlies it, the inorganic filler is likely to fall off from the cured product, making the cured product susceptible to excessive corrosion by the oxidizing agent.

[0005] An object of the present invention is to provide a photosensitive resin composition that contains a carboxyl group-containing resin, that makes it easy to lower the dielectric tangent of the cured product, that makes it easy to maintain the flexibility of the cured product, and that is not subject to excessive corrosion even when treated with an oxidizing agent; a dry film that contains this photosensitive resin composition; a cured product of this photosensitive resin composition; and a printed wiring board that includes a solder resist layer or an interlayer insulating layer that includes this cured product. [Means for solving the problem]

[0006] A photosensitive resin composition according to one embodiment of the present invention contains a carboxyl group-containing resin (A), a photopolymerization initiator (B), a photopolymerizable compound (C), an epoxy compound (D), silica (E) in a percentage of 50% by mass or more and 300% by mass or less relative to the carboxyl group-containing resin (A), and a blocked isocyanate compound (F) in a percentage of 21% by mass or more and 100% by mass or less relative to the carboxyl group-containing resin (A).

[0007] A dry film according to one aspect of the present invention contains the photosensitive resin composition.

[0008] A cured product according to one aspect of the present invention is obtained by curing the photosensitive resin composition.

[0009] A printed wiring board according to one aspect of the present invention includes an interlayer insulating layer containing the cured product.

[0010] A printed wiring board according to one aspect of the present invention includes a solder resist layer containing the cured product. [Effects of the Invention]

[0011] According to one aspect of the present invention, there can be provided a photosensitive resin composition that contains a carboxyl group-containing resin, that easily reduces the dielectric tangent of the cured product, that easily maintains the flexibility of the cured product, and that is not subject to excessive corrosion even when treated with an oxidizing agent; a dry film that contains this photosensitive resin composition; a cured product of this photosensitive resin composition; and a printed wiring board that includes a solder resist layer or an interlayer insulating layer that includes this cured product. [Brief explanation of the drawings]

[0012] [Figure 1] 1A to 1E are cross-sectional views showing steps for manufacturing a printed wiring board according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described below. Note that the embodiment described below is merely one of various embodiments of the present invention. The embodiment described below can be modified in various ways depending on the design as long as the object of the present invention can be achieved.

[0014] The photosensitive resin composition according to this embodiment contains a carboxyl group-containing resin (A), a photopolymerization initiator (B), a photopolymerizable compound (C), an epoxy compound (D), silica (E) in a percentage of 50% by mass or more and 300% by mass or less relative to the carboxyl group-containing resin (A), and a blocked isocyanate compound (F) in a percentage of 21% by mass or more and 100% by mass or less relative to the carboxyl group-containing resin (A).

[0015] According to this embodiment, the dielectric loss tangent of the cured product of the photosensitive resin composition is easily reduced. Therefore, the high-frequency characteristics of a printed wiring board including the cured product of the photosensitive resin composition are easily improved. Furthermore, the flexibility of the cured product is easily maintained, and the cured product is less likely to be excessively corroded even when treated with an oxidizing agent. The reasons for this are presumed to be as follows. However, this embodiment is not bound by the explanation of the reasons below.

[0016] When the photosensitive resin composition contains silica (E) and the percentage of silica (E) relative to the carboxyl group-containing resin (A) is 50% by mass or more, the silica (E) can reduce the dielectric dissipation factor of the cured product. When the photosensitive resin composition contains a blocked isocyanate compound (F) and the percentage of the blocked isocyanate compound (F) relative to the carboxyl group-containing resin (A) is 21% by mass or more and 100% by mass or less, the blocked isocyanate compound (F) reacts with hydroxyl groups during the curing process of the photosensitive resin composition, thereby reducing the number of hydroxyl groups in the cured product (X), thereby further reducing the dielectric dissipation factor of the cured product. Furthermore, the urethane bonds formed by this reaction enhance the flexibility of the cured product. Furthermore, the blocked isocyanate compound (F) easily bonds with hydroxyl groups on the surface of the silica (E), making it difficult for silica (E) particles to fall off from the cured product even when the surface of the cured product is treated with an oxidizing agent.

[0017] Furthermore, the blocked isocyanate compound (F) can improve the developability when forming films such as solder resist layers and interlayer insulating layers from the photosensitive resin composition by photolithography. Although the reason for this is not fully understood, it is believed that when the percentage of the blocked isocyanate compound (F) in the photosensitive resin composition is 21% by mass or more and 100% by mass or less relative to the carboxyl group-containing resin (A), the blocked isocyanate compound (F) acts as a plasticizer, making the photosensitive resin composition more compatible with a developer such as an alkaline aqueous solution, thereby facilitating the appropriate solubility or dispersion of the photosensitive resin composition in the developer. Furthermore, because the blocked isocyanate compound (F) is protected by a blocking agent, it is less likely to undergo a reaction during the process of forming a film by photolithography. This is also believed to contribute to the improved developability.

[0018] The components of the photosensitive resin composition will be described in more detail below.

[0019] The carboxyl group-containing resin (A) may contain a component having a carboxyl group having an ethylenically unsaturated group, and in this case, the carboxyl group-containing resin (A) can impart photosensitivity, specifically photocurability, to the photosensitive resin composition.

[0020] The carboxyl group-containing resin (A) preferably contains a carboxyl group-containing resin (A1) having an aromatic ring. In this case, the heat resistance and electrical insulation of the cured product of the photosensitive resin composition are likely to be improved. The carboxyl group-containing resin (A1) more preferably has a polycyclic aromatic ring selected from the group consisting of a biphenyl skeleton, a naphthalene skeleton, a fluorene skeleton, and an anthracene skeleton. In this case, the heat resistance and electrical insulation of the cured product are likely to be improved.

[0021] It is particularly preferred that the carboxyl group-containing resin (A) contains a carboxyl group-containing resin (A11) having a bisphenolfluorene skeleton, which tends to particularly improve the heat resistance and electrical insulation properties of the cured product.

[0022] The bisphenol fluorene skeleton is represented by the following formula (1).

[0023] [ka]

[0024] In formula (1), R1 to R8 are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen. That is, each of R1 to R8 in formula (1) may be hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen. Even if hydrogen in the aromatic ring is substituted with a low-molecular-weight alkyl group or a halogen, the physical properties of the carboxyl group-containing resin (A11) are not adversely affected, and in fact, the substitution may improve the heat resistance or flame retardancy of a cured product of a photosensitive resin composition containing the carboxyl group-containing resin (A11).

[0025] The carboxyl group-containing resin (A11) can be synthesized, for example, by reacting an epoxy compound (a1) having a bisphenol fluorene skeleton represented by formula (1) with an unsaturated group-containing carboxylic acid (a2), and then reacting the resulting intermediate with an acid anhydride (a3).

[0026] The epoxy compound (a1) has a structure represented by the following formula (2), for example. In formula (2), n is, for example, an integer ranging from 0 to 20. In order to appropriately control the molecular weight of the carboxyl group-containing resin (A11), the average of n is more preferably within the range of 0 to 1. When the average of n is within the range of 0 to 1, excessive increase in the molecular weight of the carboxyl group-containing resin (A11) is easily suppressed. Furthermore, in formula (2), R1 to R8 are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or halogen.

[0027] [ka]

[0028] The unsaturated group-containing carboxylic acid (a2) includes, for example, a compound having only one ethylenically unsaturated group in one molecule. More specifically, the unsaturated group-containing carboxylic acid (a2) contains at least one compound selected from the group consisting of, for example, acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≒2) monoacrylate, crotonic acid, cinnamic acid, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl phthalic acid, 2-acryloyloxypropyl phthalic acid, 2-methacryloyloxypropyl phthalic acid, 2-acryloyloxyethyl maleic acid, 2-methacryloyloxyethyl maleic acid, β-carboxyethyl acrylate, 2-acryloyloxyethyl tetrahydrophthalic acid, 2-methacryloyloxyethyl tetrahydrophthalic acid, 2-acryloyloxyethyl hexahydrophthalic acid, and 2-methacryloyloxyethyl hexahydrophthalic acid. Preferably, the unsaturated group-containing carboxylic acid (a2) contains acrylic acid. Furthermore, when the unsaturated group-containing carboxylic acid (a2) contains acrylic acid, the acrylic acid content of the unsaturated group-containing carboxylic acid (a2) is preferably 50 mol % or more, more preferably 80 mol % or more, even more preferably 85 mol % or more, and particularly preferably 90 mol % or more.

[0029] The epoxy compound (a1) and the unsaturated group-containing carboxylic acid (a2) can be reacted by any suitable method. For example, a reactive solution can be obtained by adding the unsaturated group-containing carboxylic acid (a2) to a solvent solution of the epoxy compound (a1), and then adding a thermal polymerization inhibitor and a catalyst, if necessary, and stirring and mixing. This reactive solution can be reacted by a conventional method at a temperature of preferably 60°C to 150°C, more preferably 80°C to 120°C, to obtain an intermediate. The solvent in this case can contain at least one component selected from the group consisting of ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, and propylene glycol monomethyl ether acetate, and dialkyl glycol ethers. The thermal polymerization inhibitor may contain at least one component selected from the group consisting of, for example, hydroquinone, methylhydroquinone, and hydroquinone monomethyl ether. The catalyst may contain at least one component selected from the group consisting of, for example, tertiary amines such as benzyldimethylamine and triethylamine, quaternary ammonium salts such as trimethylbenzylammonium chloride and methyltriethylammonium chloride, triphenylphosphine, and triphenylstibine.

[0030] The catalyst preferably contains triphenylphosphine. That is, it is preferable to react the epoxy compound (a1) with the unsaturated group-containing carboxylic acid (a2) in the presence of triphenylphosphine. In this case, the ring-opening addition reaction between the epoxy group in the epoxy compound (a1) and the unsaturated group-containing carboxylic acid (a2) is particularly promoted, and a reaction rate (conversion rate) of 95% or more, 97% or more, or nearly 100% can be achieved.

[0031] It is also preferable to react the epoxy compound (a1) with the unsaturated group-containing carboxylic acid (a2) under air bubbling. In this case, the addition polymerization reaction of the unsaturated group is suppressed, thereby suppressing an increase in the molecular weight of the intermediate and gelation of the intermediate solution. In addition, excessive coloration of the final product, the carboxyl group-containing resin (A11), can be suppressed.

[0032] When the epoxy compound (a1) is reacted with the unsaturated group-containing carboxylic acid (a2), the amount of the unsaturated group-containing carboxylic acid (a2) relative to 1 mole of the epoxy group of the epoxy compound (a1) is preferably 0.8 moles or more and 1.2 moles or less, in which case a photosensitive resin composition having excellent photosensitivity and stability can be obtained.

[0033] The intermediate thus obtained has a hydroxyl group formed by the reaction between the epoxy group of the epoxy compound (a1) and the carboxyl group of the unsaturated group-containing carboxylic acid (a2).

[0034] Next, the intermediate is reacted with an acid anhydride (a3), which contains, for example, an acid dianhydride (a4).

[0035] The acid dianhydride (a4) is a compound having two acid anhydride groups. The acid dianhydride (a4) can contain an anhydride of a tetracarboxylic acid. Examples of the acid dianhydride (a4) include 1,2,4,5-benzenetetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, methylcyclohexenetetracarboxylic dianhydride, tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, ethylenetetracarboxylic dianhydride, 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, glycerin bisanhydrotrimellitate monoacetate, ethylene tetracarboxylic dianhydride ... The photosensitive resin composition may contain at least one compound selected from the group consisting of glycol bisanhydrotrimellitate, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, 1,2,3,4-butanetetracarboxylic dianhydride, and 3,3',4,4'-biphenyltetracarboxylic dianhydride. It is particularly preferred that the acid dianhydride (a4) contains 3,3',4,4'-biphenyltetracarboxylic dianhydride. In this case, the photosensitive resin composition can ensure good developability, while suppressing tackiness of the film formed from the photosensitive resin composition and improving the insulation reliability and plating resistance of the cured product.

[0036] The acid anhydride (a3) ​​may contain an acid monoanhydride (a5). The acid monoanhydride (a5) is a compound having one acid anhydride group. The acid monoanhydride (a5) may contain an anhydride of a dicarboxylic acid. The acid monoanhydride (a5) may contain, for example, one or more compounds selected from the group consisting of phthalic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, methylsuccinic anhydride, maleic anhydride, citraconic anhydride, glutaric anhydride, cyclohexane-1,2,4-tricarboxylic-1,2-anhydride, and itaconic anhydride. In particular, it is preferable that the acid monoanhydride (a5) contains 1,2,3,6-tetrahydrophthalic anhydride. That is, it is preferable that the acid anhydride (a3) ​​contains 1,2,3,6-tetrahydrophthalic anhydride. In this case, while ensuring good developability of the photosensitive resin composition, the tackiness of the film formed from the photosensitive resin composition can be further suppressed and the insulating reliability and plating resistance of the cured product can be further improved. With respect to the total acid monoanhydride (a5), the content of 1,2,3,6-tetrahydrophthalic anhydride is preferably in the range of 20 mol% to 100 mol%, more preferably in the range of 40 mol% to 100 mol%, but is not limited thereto.

[0037] Any suitable method can be used to react the intermediate with the acid anhydride (a3). For example, a reactive solution is obtained by adding the acid anhydride (a3) ​​to a solvent solution of the intermediate, and then adding a thermal polymerization inhibitor and a catalyst as needed, followed by stirring and mixing. This reactive solution is reacted by a conventional method, preferably at a temperature of 60°C or higher but 150°C or lower, and particularly preferably at a temperature of 80°C or higher but 120°C or lower, to obtain a carboxyl group-containing resin (A11) having a bisphenolfluorene skeleton. Suitable solvents, catalysts, and polymerization inhibitors can be used, and the solvents, catalysts, and polymerization inhibitors used in the synthesis of the intermediate can also be used as they are.

[0038] The catalyst preferably contains triphenylphosphine. That is, it is preferable to react the intermediate with the acid anhydride (a3) ​​in the presence of triphenylphosphine. In this case, the reaction between the intermediate and the acid anhydride (a3) ​​is particularly promoted, and a reaction rate (conversion rate) of 90% or more, 95% or more, 97% or more, or even nearly 100% can be achieved.

[0039] When the acid anhydride (a3) ​​contains the acid dianhydride (a4), the amount of the acid dianhydride (a4) is preferably 0.05 mol or more and 0.24 mol or less per mol of the epoxy group of the epoxy compound (a1). In this case, a carboxyl group-containing resin (A11) having a bisphenolfluorene skeleton and having an appropriately adjusted acid value and molecular weight can be easily obtained.

[0040] When the acid anhydride (a3) ​​further contains an acid monoanhydride (a5), the amount of the acid monoanhydride (a5) is preferably 0.3 to 0.7 moles per mole of the epoxy group of the epoxy compound (a1). In this case, a carboxyl group-containing resin (A11) having a bisphenolfluorene skeleton and having an appropriately adjusted acid value and molecular weight can be easily obtained.

[0041] It is also preferred to react the intermediate with the acid anhydride (a3) ​​under air bubbling, which prevents the resulting carboxyl group-containing resin (A11) having a bisphenolfluorene skeleton from excessively increasing in molecular weight, thereby particularly improving the developability of the photosensitive resin composition with an alkaline aqueous solution.

[0042] The carboxyl group-containing resin (A) may contain a carboxyl group-containing resin that does not have a bisphenolfluorene skeleton (hereinafter also referred to as a carboxyl group-containing resin (A2)). The carboxyl group-containing resin (A) may contain at least one of a carboxyl group-containing resin (A11) and a carboxyl group-containing resin (A2).

[0043] The carboxyl group-containing resin (A2) may contain, for example, a carboxyl group-containing resin that has carboxyl groups but is not photopolymerizable (hereinafter referred to as carboxyl group-containing resin (A2-1)). The carboxyl group-containing resin (A2-1) may contain, for example, a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group. The ethylenically unsaturated compound having a carboxyl group may contain compounds such as acrylic acid, methacrylic acid, and ω-carboxy-polycaprolactone (n≒2) monoacrylate. The ethylenically unsaturated compound having a carboxyl group may also contain a reaction product of pentaerythritol triacrylate, pentaerythritol trimethacrylate, or the like with a dibasic acid anhydride. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group, such as 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, or a linear or branched aliphatic or alicyclic (which may have a partial unsaturated bond in the ring) (meth)acrylic acid ester.

[0044] The carboxyl group-containing resin (A2) may contain a carboxyl group-containing resin having a carboxyl group and an ethylenically unsaturated group (hereinafter referred to as a carboxyl group-containing resin (A2-2)). The carboxyl group-containing resin (A2-2) can impart photosensitivity, specifically photocurability, to the photosensitive resin composition. The carboxyl group-containing resin (A2) may contain only the carboxyl group-containing resin (A2-2).

[0045] The carboxyl group-containing resin (A2-2) contains, for example, a resin (hereinafter also referred to as the first resin (x)) that is a reaction product of an intermediate, which is a reaction product of an epoxy compound (x1) having two or more epoxy groups per molecule with an ethylenically unsaturated compound (x2), and at least one compound (x3) selected from the group consisting of polycarboxylic acids and their anhydrides. The first resin (x) can be obtained, for example, by reacting the epoxy group in the epoxy compound (x1) with the carboxyl group in the ethylenically unsaturated compound (x2) to obtain an intermediate, to which the compound (x3) is then added.

[0046] The epoxy compound (x1) may contain an appropriate epoxy compound such as a cresol novolac epoxy compound, a phenol novolac epoxy compound, or a biphenyl novolac epoxy compound. It is particularly preferred that the epoxy compound (x1) contains at least one compound selected from the group consisting of biphenyl novolac epoxy compounds and cresol novolac epoxy compounds. In this case, a resin included in the carboxyl group-containing resin (A1) having an aromatic ring is obtained. The epoxy compound (x1) may contain only a biphenyl novolac epoxy compound, or only a cresol novolac epoxy compound.

[0047] The epoxy compound (x1) may contain a polymer of an ethylenically unsaturated compound (z). The ethylenically unsaturated compound (z) may contain a compound (z1) having an epoxy group, such as glycidyl (meth)acrylate, or may further contain a compound (z2) not having an epoxy group, such as 2-(meth)acryloyloxyethyl phthalate. The ethylenically unsaturated compound (x2) preferably contains at least one of acrylic acid and methacrylic acid. The compound (x3) preferably contains one or more compounds selected from the group consisting of polycarboxylic acids, such as phthalic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid, and anhydrides of these polycarboxylic acids. In particular, the compound (x3) preferably contains at least one polycarboxylic acid selected from the group consisting of phthalic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid.

[0048] The carboxyl group-containing resin (A2-2) may contain a resin (referred to as "second resin (y)") that is a reaction product of a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group with an ethylenically unsaturated compound having an epoxy group. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group. The second resin (y) is obtained by reacting some of the carboxyl groups in the polymer with an ethylenically unsaturated compound having an epoxy group. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group. Examples of the ethylenically unsaturated compound having a carboxyl group include acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≒2) monoacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, and the like. Examples of the ethylenically unsaturated compound having no carboxyl group include 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, and linear or branched aliphatic or alicyclic (which may have a partial unsaturated bond in the ring) (meth)acrylic acid esters. The ethylenically unsaturated compound having an epoxy group preferably includes glycidyl (meth)acrylate.

[0049] The carboxyl group-containing resin (A) preferably contains 25 mass % or more of the carboxyl group-containing resin (A1), more preferably 40 mass % or more, even more preferably 60 mass % or more, and particularly preferably 100 mass % of the carboxyl group-containing resin (A1), which can particularly improve the heat resistance and insulating reliability of the cured product of the photosensitive resin composition.

[0050] The carboxyl group-containing resin (A) preferably contains 25% by mass or more of the carboxyl group-containing resin (A11), more preferably 40% by mass or more, even more preferably 60% by mass or more, and particularly preferably 100% by mass. In this case, the photosensitive resin composition can have excellent photosensitivity and developability with an alkaline aqueous solution. Furthermore, the heat resistance and insulating reliability of the cured product of the photosensitive resin composition can be particularly improved, and the dielectric constant can be reduced. Furthermore, the tackiness of the film formed from the photosensitive resin composition can be sufficiently reduced.

[0051] The weight-average molecular weight of the carboxyl group-containing resin (A) is preferably 700 or more and 100,000 or less. When the weight-average molecular weight of the carboxyl group-containing resin (A) is 700 or more, the tackiness of the film formed from the photosensitive resin composition is easily suppressed, and the insulating reliability and plating resistance of the cured product of the photosensitive resin composition can be improved. When the weight-average molecular weight of the carboxyl group-containing resin (A) is 100,000 or less, the developability of the photosensitive resin composition with an alkaline aqueous solution is easily improved. The weight-average molecular weight of the carboxyl group-containing resin (A) is more preferably 900 or more and 60,000 or less, even more preferably 1,200 or more and 10,000 or less, and particularly preferably 1,400 or more and 5,000 or less. The weight-average molecular weight of the carboxyl group-containing resin (A) is calculated, for example, from the results of gel permeation chromatography measurement under the following conditions.

[0052] GPC equipment: SHODEX SYSTEM 11 manufactured by Showa Denko Co., Ltd. Column: SHODEX KF-800P, KF-005, KF-003, KF-001, 4 columns in series Mobile phase: THF, Flow rate: 1ml / min, Column temperature: 45°C, Detector: RI, Conversion: Polystyrene.

[0053] The carboxyl group-containing resin (A) preferably contains a component with an acid value of 65 mgKOH / g or more and 150 mgKOH / g or less. In this case, the developability of the photosensitive resin composition with an alkaline aqueous solution is particularly likely to be improved. The acid value is more preferably 70 mgKOH / g or more and 145 mgKOH / g or less, even more preferably 75 mgKOH / g or more and 140 mgKOH / g or less, and particularly preferably 85 mgKOH / g or more and 135 mgKOH / g or less.

[0054] The percentage of the carboxyl group-containing resin (A) relative to the solid content of the photosensitive resin composition is preferably 5% by mass or more and 85% by mass or less, more preferably 10% by mass or more and even more preferably 20% by mass or more, and more preferably 75% by mass or less and even more preferably 50% by mass or less.

[0055] The percentage of the carboxyl group-containing resin (A1) relative to the solid content of the photosensitive resin composition is preferably 5% by mass or more and 85% by mass or less, more preferably 10% by mass or more and even more preferably 20% by mass or more, and more preferably 75% by mass or less and even more preferably 50% by mass or less.

[0056] The percentage of the carboxyl group-containing resin (A11) relative to the solid content of the photosensitive resin composition is preferably 5% by mass or more and 85% by mass or less, more preferably 10% by mass or more, and even more preferably 20% by mass or more, and more preferably 75% by mass or less, and even more preferably 50% by mass or less.

[0057] The photopolymerization initiator (B) will be explained.

[0058] The photopolymerization initiator (B) is a component that can improve the photosensitivity of the photosensitive resin composition. The photopolymerization initiator (B) preferably contains at least one selected from the group consisting of, for example, an α-aminoalkylphenone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator. In this case, when the photosensitive resin composition is exposed to light such as ultraviolet light, high photosensitivity can be imparted to the photosensitive resin composition. The photopolymerization initiator (B) more preferably contains an acylphosphine oxide-based photopolymerization initiator (B1). In this case, high photosensitivity can be imparted to the photosensitive resin composition, and the insulating reliability of the cured product of the photosensitive resin composition can be particularly improved.

[0059] The α-aminoalkylphenone photopolymerization initiator may contain at least one component selected from the group consisting of, for example, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone.

[0060] Examples of the acylphosphine oxide photopolymerization initiator (B1) include monoacylphosphine oxide photopolymerization initiators such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and 2,4,6-trimethylbenzoyl-ethyl-phenyl-phosphinate, as well as bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, and bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide. The photopolymerization initiator may contain at least one component selected from the group consisting of bisacylphosphine oxide-based photopolymerization initiators such as phosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and (2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide.

[0061] The oxime ester photopolymerization initiator can contain at least one component selected from the group consisting of, for example, 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime).

[0062] The photosensitive resin composition may further contain an appropriate photopolymerization accelerator, a sensitizer, etc. For example, the photosensitive resin composition may contain hydroxyketones such as 1-hydroxycyclohexylphenylketone, phenylglyoxylic acid methyl ester, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-methylpropan-1-one, and 2-hydroxy-2-methyl-1-phenyl-propan-1-one; benzoin and its alkyl ethers; acetophenones such as acetophenone and benzil dimethyl ketal; anthraquinones such as 2-methylanthraquinone; 2,4-dimethyl The photosensitive resin composition may contain at least one component selected from the group consisting of thioxanthones such as methylthioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, and 2,4-diisopropylthioxanthone; benzophenones such as benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and bis(diethylamino)benzophenone; xanthones such as 2,4-diisopropylxanthone; α-hydroxyketones such as 2-hydroxy-2-methyl-1-phenyl-propan-1-one; and nitrogen-containing compounds such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone. The photosensitive resin composition may contain, in addition to the photopolymerization initiator (B), an appropriate photopolymerization accelerator and sensitizer, such as a tertiary amine such as p-dimethylbenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ester, or 2-dimethylaminoethyl benzoate. The photosensitive resin composition may contain at least one of a photopolymerization initiator for visible light exposure and a photopolymerization initiator for near-infrared exposure, as needed. The photosensitive resin composition may contain, together with the photopolymerization initiator (B), a sensitizer for laser exposure, such as a coumarin derivative such as 7-diethylamino-4-methylcoumarin, a carbocyanine dye, or a xanthene dye.

[0063] The photopolymerization initiator (B) preferably contains a hydroxyketone-based photopolymerization initiator (B2) in addition to the acylphosphine oxide-based photopolymerization initiator (B1). That is, the photosensitive resin composition preferably contains the hydroxyketone-based photopolymerization initiator (B2). In this case, the photosensitive resin composition can be imparted with higher photosensitivity than a composition that does not contain the hydroxyketone-based photopolymerization initiator (B2). This makes it possible to sufficiently cure the coating from its surface to its depths when the coating formed from the photosensitive resin composition is cured by irradiating it with ultraviolet light. Examples of the hydroxyketone-based photopolymerization initiator (B2) include 1-hydroxycyclohexylphenyl ketone, phenylglyoxylic acid methyl ester, 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, and 2-hydroxy-2-methyl-1-phenyl-propan-1-one.

[0064] The mass ratio ((B1):(B2)) of the acylphosphine oxide photopolymerization initiator (B1) to the hydroxyketone photopolymerization initiator (B2) is preferably within the range of 1:0.01 to 1:10. In this case, the curability near the surface of the coating film formed from the photosensitive resin composition can be improved in a well-balanced manner between the curability in the deeper portion and the curability near the surface.

[0065] The photopolymerization initiator (B) preferably contains bis(diethylamino)benzophenone (B3). That is, the photosensitive resin composition preferably contains an acylphosphine oxide-based photopolymerization initiator (B1) and bis(diethylamino)benzophenone (B3), or an acylphosphine oxide-based photopolymerization initiator (B1), a hydroxyketone-based photopolymerization initiator (B2), and bis(diethylamino)benzophenone (B3). In this case, when a coating film formed from the photosensitive resin composition is partially exposed to light and then developed, curing of the unexposed areas is suppressed, resulting in particularly high resolution. This makes it possible to form very fine patterns with the cured product of the photosensitive resin composition. In particular, when an interlayer insulating layer of a multilayer printed wiring board is produced from the photosensitive resin composition and small-diameter holes for through-holes are formed in the interlayer insulating layer by photolithography, small-diameter holes can be formed precisely and easily.

[0066] The percentage of bis(diethylamino)benzophenone (B3) relative to the acylphosphine oxide photopolymerization initiator (B1) is preferably 0.5% by mass or more and 20% by mass or less. When the bis(diethylamino)benzophenone (B3) is 0.5% by mass or more, the resolution is particularly high. Furthermore, when the bis(diethylamino)benzophenone (B3) is 20% by mass or less, the bis(diethylamino)benzophenone (B3) is less likely to impair the electrical insulation properties of the cured product of the photosensitive resin composition.

[0067] The percentage of the photopolymerization initiator (B) relative to the carboxyl group-containing resin (A) is preferably 0.1% by mass or more and 30% by mass or less, and more preferably 1% by mass or more and 25% by mass or less.

[0068] The percentage of the photopolymerization initiator (B) relative to the entire photosensitive resin composition (solid content) is preferably 0.001% by mass or more and 6% by mass or less, and more preferably 0.01% by mass or more and 3% by mass or less.

[0069] The photopolymerizable compound (C) will now be described.

[0070] The photopolymerizable compound (C) can impart photosensitivity, specifically photocurability, to the photosensitive resin composition. Note that the photopolymerizable compound (C) excludes the compounds contained in the carboxyl group-containing resin (A).

[0071] The photopolymerizable compound (C) contains, for example, a compound having an ethylenically unsaturated bond. More specifically, the photopolymerizable compound (C) contains at least one compound selected from the group consisting of monofunctional (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, and polyfunctional (meth)acrylates such as diethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ε-caprolactone-modified pentaerythritol hexaacrylate, and tricyclodecane dimethanol di(meth)acrylate.

[0072] The photopolymerizable compound (C) preferably contains a compound (C1) having a tricyclodecane skeleton. The compound (C1) having a tricyclodecane skeleton contains, for example, tricyclodecane dimethanol di(meth)acrylate. In this case, the dielectric loss tangent of the cured product is more likely to be reduced. The percentage of the compound (C1) having a tricyclodecane skeleton relative to the photopolymerizable compound (C) is preferably 20% by mass or more, more preferably 40% by mass or more, and even more preferably 60% by mass or more.

[0073] The photopolymerizable compound (C) preferably contains a trifunctional compound, i.e., a compound having three unsaturated bonds in one molecule. In this case, the developability and resolution are further improved when a film is produced from the photosensitive resin composition by photolithography. The trifunctional compound may contain at least one compound selected from the group consisting of trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, ε-caprolactone-modified tris-(2-acryloxyethyl)isocyanurate, and ethoxylated glycerin tri(meth)acrylate.

[0074] The photopolymerizable compound (C) preferably contains a phosphorus-containing compound (phosphorus-containing unsaturated compound). In this case, the flame retardancy of the cured product of the photosensitive resin composition is improved. Examples of the phosphorus-containing unsaturated compound include 2-methacryloyloxyethyl acid phosphate (specifically, product numbers Light Ester P-1M and Light Ester P-2M manufactured by Kyoeisha Chemical Co., Ltd.), 2-acryloyloxyethyl acid phosphate (specifically, product number Light Acrylate P-1A manufactured by Kyoeisha Chemical Co., Ltd.), diphenyl-2-methacryloyloxyethyl phosphate (specifically, product number MR-260 manufactured by Daihachi Kogyo Co., Ltd.), and the HFA series manufactured by Showa Polymer Co., Ltd. (specifically, product number Diphenyl 2-methacryloyloxyethyl phosphate). The composition may contain at least one compound selected from the group consisting of products of addition reaction between dipentaerythritol hexaacrylate and HCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide), product numbers HFA-6003 and HFA-6007, and products of addition reaction between caprolactone-modified dipentaerythritol hexaacrylate and HCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide), product numbers HFA-3003 and HFA-6127, etc.

[0075] The photopolymerizable compound (C) may contain a prepolymer. The prepolymer may contain at least one compound selected from the group consisting of prepolymers obtained by polymerizing a monomer having an ethylenically unsaturated bond and then adding an ethylenically unsaturated group, and oligo(meth)acrylate prepolymers. The oligo(meth)acrylate prepolymer may contain at least one component selected from the group consisting of epoxy(meth)acrylate, polyester(meth)acrylate, urethane(meth)acrylate, alkyd resin(meth)acrylate, silicone resin(meth)acrylate, and spiran resin(meth)acrylate.

[0076] The percentage of the photopolymerizable compound (C) relative to the carboxyl group-containing resin (A) is preferably 1% by mass or more and 50% by mass or less, more preferably 10% by mass or more, and even more preferably 21% by mass or more, and more preferably 45% by mass or less, and even more preferably 40% by mass or less.

[0077] The epoxy compound (D) will be explained.

[0078] The epoxy compound (D) can react with the carboxyl group in the carboxyl group-containing resin (A), and can therefore impart thermosetting properties to the photosensitive resin composition.

[0079] The epoxy compound (D) preferably contains a crystalline epoxy compound (D1). In this case, developability is more likely to be improved. Furthermore, when the organic filler (G) described below contains an organic filler having a carboxyl group, the carboxyl group in the organic filler facilitates dissolution of the crystalline epoxy compound (D1) in the photosensitive resin composition. This makes it difficult for the crystalline epoxy compound (D1) to recrystallize.

[0080] The epoxy compound (D) may further contain an amorphous epoxy compound (D2). Note that a "crystalline epoxy compound" is an epoxy compound that has a melting point, and an "amorphous epoxy compound" is an epoxy compound that does not have a melting point.

[0081] Examples of the crystalline epoxy compound (D1) include 1,3,5-tris(2,3-epoxypropyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, hydroquinone-type crystalline epoxy compounds (specifically, a product of Nippon Steel & Sumikin Chemical Co., Ltd., under the trade name YDC-1312), biphenyl-type crystalline epoxy compounds (specifically, a product of Mitsubishi Chemical Corporation, under the trade name YX-4000), diphenyl ether-type crystalline epoxy compounds (specifically, a product of Nippon Steel & Sumikin Chemical Co., Ltd., under the trade name YSLV-80DE), bisphenol-type crystalline epoxy compounds (specifically, a product of Nippon Steel & Sumikin Chemical Co., Ltd., under the trade names YSLV-70XY and YSLV-80XY), tetrakisphenolethane-type crystalline epoxy compounds (specifically, a product of Nippon Kayaku Co., Ltd., under the trade name GTR-1800), and bisphenolfluorene-type crystalline epoxy compounds (specifically, The structure shown in formula (2) It is preferable that the epoxy resin contains one or more components selected from the group consisting of:

[0082] The crystalline epoxy compound (D1) preferably has two epoxy groups in one molecule, which makes it even more difficult for cracks to occur in the cured product when subjected to repeated temperature changes.

[0083] The epoxy equivalent of the crystalline epoxy compound (D1) is preferably 150 g / eq or more and 300 g / eq or less. This epoxy equivalent is the gram weight of the crystalline epoxy compound (D1) containing 1 gram equivalent of epoxy groups. The crystalline epoxy compound (D1) has a melting point. The melting point of the crystalline epoxy compound (D1) is, for example, 70°C or more and 180°C or less.

[0084] In particular, the epoxy compound (D) preferably contains a crystalline epoxy compound (D1-1) having a melting point of 110°C or less. In this case, the developability of the photosensitive resin composition with an alkaline aqueous solution is particularly likely to be improved. The crystalline epoxy compound (D1-1) having a melting point of 110°C or less can contain at least one component selected from the group consisting of biphenyl-type epoxy resins (specifically, product number YX-4000 manufactured by Mitsubishi Chemical Corporation), biphenyl ether-type epoxy resins (specifically, product number YSLV-80DE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), bisphenol-type epoxy resins (specifically, product numbers YSLV-70XY and YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), and bisphenolfluorene-type crystalline epoxy compounds.

[0085] Examples of the amorphous epoxy compound (D2) include phenol novolac epoxy resins (specifically, EPICLO N-775 manufactured by DIC Corporation), cresol novolac epoxy resins (specifically, EPICLONN-695 manufactured by DIC Corporation), bisphenol A novolac epoxy resins (specifically, EPICLO N-865 manufactured by DIC Corporation), bisphenol A epoxy resins (specifically, jER1001 manufactured by Mitsubishi Chemical Corporation), bisphenol F epoxy resins (specifically, jER4004P manufactured by Mitsubishi Chemical Corporation), bisphenol S epoxy resins (specifically, EPICLO EXA-1514 manufactured by DIC Corporation), bisphenol AD ​​epoxy resins, biphenyl novolac epoxy resins (specifically, NC-3000 manufactured by Nippon Kayaku Co., Ltd.), hydrogenated bisphenol A epoxy resins (specifically, ST-4000D manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), naphthalene epoxy resins (specifically, EPICLO N-865 manufactured by DIC Corporation), and the like. HP-4032, EPICLON HP-4700, EPICLON HP-4770), tertiary butyl catechol type epoxy resin (specifically, DIC Corporation's product number EPICLON HP-820), dicyclopentadiene type epoxy resin (specifically, DIC Corporation's product number EPICLON HP-7200), adamantane type epoxy resin (specifically, Idemitsu Kosan Co., Ltd.'s product number ADAMANTATEX-E-201), special bifunctional epoxy resin (specifically, Mitsubishi Chemical Corporation's product numbers YL7175-500 and YL7175-1000; DIC Corporation's product numbers EPICLON TSR-960, EPICLON TER-601, EPICLON TSR-250-80BX, EPICLON 1650-75MPX, EPICLON EXA-4850, EPICLON EXA-4816, EPICLON EXA-4822, and EPICLONEXA-9726;It is preferable that the epoxy resin contains at least one component selected from the group consisting of a rubbery core-shell polymer modified bisphenol A type epoxy resin (specifically, a product number MX-156 manufactured by Kaneka Corporation), a rubbery core-shell polymer modified bisphenol F type epoxy resin (specifically, a product number MX-136 manufactured by Kaneka Corporation), and a rubber particle-containing bisphenol F type epoxy resin (specifically, a product number Kane Ace MX-130 manufactured by Kaneka Corporation);

[0086] The epoxy compound (D) may contain a phosphorus-containing epoxy resin. In this case, the flame retardancy of the cured product of the photosensitive resin composition is improved. The phosphorus-containing epoxy resin may be contained in the crystalline epoxy compound (D1) or the amorphous epoxy compound (D2). Examples of the phosphorus-containing epoxy resin include phosphoric acid-modified bisphenol F epoxy resins (specific examples of which include EPICLON EXA-9726 and EPICLON EXA-9710 manufactured by DIC Corporation) and Epotohto FX-305 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.

[0087] Regarding the amount of epoxy compound (D) in the photosensitive resin composition, the epoxy group equivalent of the epoxy compound (D) is preferably 0.1 or more but less than 1 per carboxyl group equivalent of the carboxyl group-containing resin (A). In this case, the dielectric loss tangent of the cured product is likely to be reduced while maintaining the thermosetting properties of the photosensitive resin composition. Therefore, the cured product is likely to have even better dielectric properties. The epoxy group equivalent is more preferably 0.9 or less, and even more preferably 0.8 or less. Furthermore, the epoxy group equivalent is more preferably 0.5 or more, and even more preferably 0.7 or more.

[0088] Silica (E) will be explained.

[0089] As described above, when the photosensitive resin composition contains silica (E) and the percentage of silica (E) is 50% by mass or more relative to the carboxyl group-containing resin (A), the dielectric loss tangent of the cured product is likely to be reduced. Furthermore, silica (E) reduces the linear expansion coefficient of the cured product, thereby making it less likely for warping to occur in printed wiring boards having a layer made from the cured product. Furthermore, when the percentage of silica (E) is 300% by mass or less, the flexibility of the cured product is likely to be maintained. The percentage of silica (E) is preferably 100% by mass or more, and more preferably 130% by mass or more. Furthermore, this percentage is more preferably 250% by mass or less, and even more preferably 220% by mass or less.

[0090] The silica (E) preferably contains silica (E1) having an average particle size of 0.1 μm or more and 5 μm or less. In this case, when the surface of the cured product is treated with an oxidizing agent, fine irregularities are likely to form on the cured product, which increases the surface area of ​​the cured product. This tends to improve adhesion between the cured product and the conductor when a conductor is produced by plating the surface of the cured product. Furthermore, light scattering by the silica (E) is less likely to occur, thereby improving resolution. The average particle size of the silica (E1) is more preferably 3 μm or less, and even more preferably 2 μm or less. Furthermore, this average particle size is more preferably 0.2 μm or more, and even more preferably 0.4 μm or more. The average particle size of the silica (E1) is the cumulative 50% diameter (median diameter D50) calculated from the particle size distribution obtained by laser diffraction / scattering.

[0091] Silica (E) may contain silica (E2) having an average particle size of 1 nm or more and 150 nm or less. In this case, when the cured product is treated with an oxidizing agent, the cured product is less likely to be excessively corroded, and particularly fine irregularities are likely to form on the surface of the cured product. The average particle size of silica (E2) is preferably 5 nm or more, even more preferably 20 nm or more, and particularly preferably 25 nm or more. The average particle size of silica (E2) is more preferably 120 nm or less, even more preferably 85 nm or less, and particularly preferably 65 nm or less. The average particle size of silica (E2) is the cumulative 50% diameter (median diameter D50) calculated from the particle size distribution obtained by dynamic light scattering.

[0092] The silica (E2) may contain two or more types of silica having different average particle sizes, which further increases the resolution and makes it easier to form fine irregularities on the surface of the cured product when the surface of the cured product is treated with an oxidizing agent.

[0093] Silica (E2) may contain at least two types of silica (E21) and silica (E22) having different average particle sizes. The larger silica (E21) has an average particle size of, for example, 20 nm or more and 100 nm or less, and the smaller silica (E22) has an average particle size of, for example, 1 nm or more and less than 20 nm. The average particle size of silica (E21) is preferably 20 nm or more, and even more preferably 30 nm or more. The average particle size of silica (E21) is more preferably less than 70 nm, and even more preferably 60 nm or less. For example, when the average particle size of silica (E21) is 20 nm or more and 100 nm or less, the average particle size of silica (E22) is preferably 1 nm or more and 15 nm or less, and even more preferably 10 nm or more and 15 nm or less. The mass ratio of silica (E21) to silica (E22) is preferably 20:80 to 80:20. In this case, the thermal expansion coefficient of the cured product can be further reduced, and the dielectric loss tangent can be further reduced.

[0094] The silica (E2) preferably contains silica particles derived from silica sol. In this case, the transparency of the photosensitive resin composition can be improved. Therefore, the silica (E) can contribute to improving the resolution. Examples of silica sol include spherical silica sol and chain silica sol. Specific examples of silica sol include organosilica sol manufactured by Nissan Chemical Industries, Ltd., with product numbers MA-ST-M, MA-ST-L, IPA-ST, IPA-ST-ZL, IPA-ST-UP, EG-ST, NPC-ST-30, PGM-ST, DMAC-ST, MEK-ST-40, MIBK-ST, MIBK-ST-L, CHO-ST-M, EAC-ST, TOL-ST, MEK-AC-4130Y, MEK-AC-5140Z, PGM-AC-2140Y, PGM-AC-4130Y, MIBK-AC-2140Z, MIKB-SD-L, and MEK-EC-6150. P, MEK-EC-7150P, EP-F2130Y, EP-F6140P, EP-F7150P, PMA-ST, MEK-EC-2130Y, MEK-AC-2140Z, MEK-ST-L, MEK-ST-ZL, MEK-ST-UP; NANOCRYL manufactured by Hanse-Chemie: product numbers XP0396, XP0596, XP0733, XP0746, XP0765, XP0768, XP0953, XP0954, XP1045; NANOPOX manufactured by Hanse-Chemie: product numbers XP0516, XP0525, XP0314, etc.

[0095] The silica (E) may contain silica (E1) and silica (E2). In this case, the mass ratio of silica (E1) to silica (E2) is, for example, 50:1 to 2:1.

[0096] The photosensitive resin composition may contain an inorganic filler other than silica (E). The inorganic filler may contain at least one selected from the group consisting of barium sulfate, carbon nanotubes, talc, bentonite, aluminum hydroxide, magnesium hydroxide, and titanium oxide. The total percentage of silica (E) and the other inorganic filler in the photosensitive resin composition is preferably 50% by mass or more and 300% by mass or less relative to the carboxyl group-containing resin (A).

[0097] The silica (E) is preferably surface-treated with a silane coupling agent. In this case, the dispersibility of the silica (E) in the photosensitive resin composition and the cured product is likely to be improved. In addition, the silica (E) particles are more likely to be retained in the cured product, and when the surface of the cured product is treated with an oxidizing agent, the silica (E) particles are less likely to fall off from the cured product. Therefore, the surface of the cured product is less likely to be excessively corroded by the oxidizing agent.

[0098] Examples of silane coupling agents include tetraethoxysilane, tetramethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane. , p-Styryltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, N,N-dimethyl-3-(trimethoxysilyl)propylamine, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, allyltriethoxysilane, allyltrimethoxysilane, methylchlorodimethylsilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-chloropropyldimethoxymethylsilane, chloromethyltriethoxysilane, chloromethyltrimethoxysilane, 3-chloropropylmethyldiethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, cyclohexyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxysilane Silane, ethyltriethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexadecyltrimethoxysilane, octadecyltriethoxysilane, octadecyltrimethoxysilane, n-octyltriethoxysilane, n-octyltrimethoxysilane, dodecyltriethoxysilane, dodecyltrimethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, benzyltriethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane It contains at least one selected from the group consisting of silane, phenyltriethoxysilane, phenyltrimethoxysilane, p-tolyltrimethoxysilane, 4-vinylphenyltrimethoxysilane, 1-naphthyltrimethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 11-pentafluorophenoxyundecyltrimethoxysilane, pentafluorophenyltrimethoxysilane, 11-azidoundecyltrimethoxysilane, 2-cyanoethyltriethoxysilane, vinyltriacetoxysilane, and the like.

[0099] The silane coupling agent preferably has a phenyl skeleton. silica Furthermore, when the carboxyl group-containing resin (A) contains a carboxyl group-containing resin (A1) having an aromatic ring or a carboxyl group-containing resin (A11) having a bisphenolfluorene skeleton, silica The particles (E) are particularly resistant to falling off.

[0100] Only a part of the silica (E) may be surface-treated with a silane coupling agent. For example, when the silica (E) contains silica (E1) and silica (E2), only the silica (E1) may be surface-treated with a silane coupling agent.

[0101] The blocked isocyanate compound (F) will now be described.

[0102] As described above, the blocked isocyanate compound (F) can reduce the dielectric tangent of the cured product, increase the flexibility of the cured product, and further make the cured product less susceptible to excessive corrosion when the surface of the cured product is treated with an oxidizing agent.

[0103] As mentioned above, it is believed that the above-mentioned effect is achieved by the reaction of the blocked isocyanate compound (F) with hydroxyl groups. Examples of hydroxyl groups that can react with the blocked isocyanate compound (F) include hydroxyl groups contained in the carboxyl group-containing resin (A), hydroxyl groups generated by the reaction of the carboxyl group-containing resin (A) with the epoxy compound (D), and hydroxyl groups present on the surface of the silica (E). For example, when the carboxyl group-containing resin (A) contains a compound obtained by reacting a carboxylic acid or carboxylic anhydride with a secondary hydroxyl group in an intermediate obtained by the reaction of an epoxy compound with an unsaturated compound having a carboxyl group, the hydroxyl group in the intermediate can be an unreacted secondary hydroxyl group derived from this intermediate. The carboxyl group-containing resin (A11) and the second resin (y) described above can have such hydroxyl groups.

[0104] Furthermore, as described above, the blocked isocyanate compound (F) can improve the developability when a film is produced from the photosensitive resin composition by photolithography.

[0105] As described above, the percentage of the blocked isocyanate compound (F) relative to the carboxyl group-containing resin (A) is 21% by mass or more and 100% by mass or less, thereby achieving the above-mentioned effects of the blocked isocyanate compound (F). That is, a percentage of 21% by mass or more can reduce the dielectric tangent of the cured product, increase the flexibility of the cured product, and make the surface of the cured product treated with an oxidizing agent less susceptible to excessive corrosion, further improving developability. Furthermore, a percentage of 100% by mass or less can improve developability. A percentage of 24% by mass or more is more preferable, and a percentage of 40% by mass or more is even more preferable. A percentage of 90% by mass or less is more preferable, and a percentage of 80% by mass or less is even more preferable.

[0106] The blocked isocyanate compound (F) will be further described in detail below. The blocked isocyanate compound (F) is a compound obtained by blocking an isocyanate compound with a blocking agent.

[0107] The number of isocyanate groups in one molecule of the isocyanate compound is, for example, from 2 to 6. The isocyanate compound may be an aliphatic, alicyclic, or aromatic polyisocyanate. Examples of the isocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, 1,3-trimethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 1,9-nonamethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 2,2'-diethyl ether diisocyanate, diphenylmethane-4,4'-diisocyanate, o-xylene diisocyanate, m-xylene diisocyanate, The isocyanate compound contains at least one selected from the group consisting of isocyanate compounds such as 1,3-dimethylene diisocyanate, p-xylene diisocyanate, methylenebis(cyclohexyl isocyanate), cyclohexane-1,3-dimethylene diisocyanate, cyclohexane-1,4-dimethylene diisocyanate, 1,5-naphthalene diisocyanate, p-phenylene diisocyanate, 3,3'-methylene dentrylene-4,4'-diisocyanate, 4,4'-diphenyl ether diisocyanate, tetrachlorophenylene diisocyanate, norbornane diisocyanate, hydrogenated 1,3-xylylene diisocyanate, and hydrogenated 1,4-xylylene diisocyanate, as well as polymers thereof. In particular, the isocyanate compound preferably contains at least one compound selected from the group consisting of tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and polymers thereof. Examples of the polymer include biuret compounds, isocyanurate compounds, and adduct compounds, with biuret compounds being preferred.

[0108] Examples of blocking agents in the blocked isocyanate compound (F) include oxime compounds, lactam compounds, phenol compounds, alcohol compounds, amine compounds, active methylene compounds, pyrazole compounds, mercaptan compounds, imidazole compounds, and imide compounds. It is particularly preferred that the blocking agent contains at least one compound selected from the group consisting of oxime compounds, lactam compounds, phenol compounds, alcohol compounds, amine compounds, active methylene compounds, and pyrazole compounds. Examples of oxime compounds include oximes and ketoximes, such as acetoxime, formaldoxime, cyclohexaneoxime, methyl ethyl ketoneoxime, cyclohexanoneoxime, and benzophenoneoxime. Examples of lactam compounds include ε-caprolactam and γ-butyrolactam. Examples of phenol compounds include phenol, naphthol, cresol, xylenol, and halogen-substituted phenols. Examples of alcohol compounds include methanol, ethanol, propanol, butanol, cyclohexanol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, and alkyl lactate. Examples of amine compounds include primary amines and secondary amines, such as aniline, diphenylamine, ethyleneimine, and polyethyleneimine. Examples of active methylene compounds include diethyl malonate, dimethyl malonate, ethyl acetoacetate, and methyl acetoacetate. Examples of pyrazole compounds include pyrazole, methylpyrazole, and dimethylpyrazole. Examples of mercaptan compounds include alkyl mercaptans and aryl mercaptans.

[0109] The photosensitive resin composition may further contain an organic filler (G). The organic filler (G) imparts thixotropy to the photosensitive resin composition, thereby improving the storage stability of the photosensitive resin composition. In addition, the organic filler (G) can further improve the adhesion between the cured product and the conductor.

[0110] The organic filler (G) preferably has a reactive group. In this case, the organic filler (G) has high compatibility in the photosensitive resin composition and imparts stronger thixotropy to the photosensitive resin composition, thereby further improving the storage stability of the photosensitive resin composition. Furthermore, the adhesion between the cured product and the conductor is further improved. The reactive group possessed by the organic filler (G) more preferably contains at least one group selected from the group consisting of a carboxyl group, an amino group, an epoxy group, a vinyl group, and a hydroxyl group, and even more preferably contains at least one of a carboxyl group and an amino group. In this case, the storage stability of the photosensitive resin composition is further improved. Furthermore, the adhesion between the cured product and the conductor is further improved.

[0111] The reactive group particularly preferably contains a carboxyl group. In this case, the developability of the photosensitive resin composition is improved. Furthermore, the carboxyl group of the organic filler (G) can react with the epoxy compound (D) in the photosensitive resin composition. This facilitates uniform dispersion of the organic filler (G) within the cured product. Furthermore, the carboxyl group of the organic filler (G) can enhance adhesion between the cured product and the conductor. Furthermore, when the photosensitive resin composition contains a crystalline epoxy compound (D1), the compatibility of the crystalline epoxy compound (D1) in the photosensitive resin composition can be improved, making it less likely for the crystalline epoxy compound (D1) to crystallize. Furthermore, when the photosensitive resin composition flows to form a coating film, the coating film is less likely to become non-uniform, which facilitates uniform thickness of layers such as solder resist layers and interlayer insulating layers produced from the photosensitive resin composition.

[0112] It is also preferable that the reactive group contains a hydroxyl group. In this case, too, it is easy to further improve the adhesion between the cured product of the composition and the conductor. The reactive group may contain both a carboxyl group and a hydroxyl group.

[0113] When the organic filler (G) has a carboxyl group, the carboxyl group is formed as a side chain in the product by polymerizing or crosslinking a carboxylic acid monomer such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, etc. The carboxylic acid monomer has a carboxyl group and a polymerizable unsaturated double bond.

[0114] When the organic filler (G) has a carboxyl group, the acid value of the organic filler (G) is preferably 1 mgKOH / g or more and 60 mgKOH / g or less. If the acid value is 1 mgKOH / g or more, the stability of the photosensitive resin composition and the developability of the cured product tend to be particularly high. If the acid value is 60 mgKOH / g or less, the moisture resistance reliability of the cured product tends to be improved. The acid value of the organic filler (G) is more preferably 3 mgKOH / g or more. Furthermore, this acid value is more preferably 40 mgKOH / g or less.

[0115] The organic filler (G) preferably contains rubber particles. It is also preferable that the organic filler (G) contains only rubber particles. The rubber particles can further enhance the flexibility of the cured product. The rubber particles may have a crosslinked structure. The rubber particles contain, for example, at least one polymer selected from the group consisting of crosslinked acrylic rubber, crosslinked acrylonitrile-butadiene rubber (NBR), crosslinked methyl methacrylate-butadiene-styrene (MBS), and crosslinked styrene-butadiene rubber (SBR). In this case, the flexibility of the cured product is particularly likely to be improved. Furthermore, the surface of the cured product is more likely to be roughened appropriately when treated with an oxidizing agent.

[0116] Specific examples of rubber particles include JSR Corporation's product numbers XER-91-MEK, XER-32-MEK, and XSK-500. XER-91-MEK is a crosslinked rubber (NBR) having carboxyl groups with an average primary particle size of 0.07 μm. It is provided as a methyl ethyl ketone dispersion containing 15% by weight of this crosslinked rubber and has an acid value of 10.0 mgKOH / g. XER-32-MEK is a dispersion in which a polymer (linear particles) of carboxyl-modified hydrogenated nitrile rubber is dispersed in methyl ethyl ketone at a content of 17% by weight based on the total amount of the dispersion. XSK-500 is a crosslinked rubber (SBR) having carboxyl groups and hydroxyl groups with an average primary particle size of 0.07 μm. It is provided as a methyl ethyl ketone dispersion containing 15% by weight of this crosslinked rubber. In this way, the organic filler (G) may be blended into the photosensitive resin composition in the form of a dispersion. That is, the rubber particles may be blended into the photosensitive resin composition in the form of a dispersion. Specific examples of the organic filler (G) include, in addition to the above, product number XER-92 manufactured by JSR Corporation.

[0117] The average particle size of the organic filler (G) is preferably 1 μm or less. In this case, the developability of the photosensitive resin composition is more likely to be improved. Furthermore, when the surface of the cured product is treated with an oxidizing agent, fine irregularities are more likely to be formed on the cured product, which tends to increase the surface area of ​​the cured product. This tends to improve the adhesion between the cured product and the conductor. The average particle size of the organic filler (G) is more preferably 0.5 μm or less, and even more preferably 0.3 μm or less. In this case, light scattering in the photosensitive resin composition can be suppressed, which tends to further improve resolution. Furthermore, roughening the surface of the cured product tends to make the irregularities formed finer. Furthermore, the average particle size of the organic filler (G) is, for example, 0.001 μm or more. The average particle size of the organic filler (G) is the cumulative 50% diameter (median diameter % D50) calculated from the particle size distribution measured by dynamic light scattering.

[0118] The organic filler (G) may contain particles other than rubber particles. In this case, the organic filler (G) may contain at least one type of particle selected from the group consisting of acrylic resin particles having carboxyl groups and cellulose particles having carboxyl groups. The acrylic resin particles having carboxyl groups may contain at least one type of particle component selected from the group consisting of non-crosslinked styrene-acrylic resin particles and crosslinked styrene-acrylic resin particles. A specific example of non-crosslinked styrene-acrylic resin particles is product number FS-201 (average primary particle diameter 0.5 μm) manufactured by Nippon Paint Industrial Coatings Co., Ltd. Specific examples of crosslinked styrene-acrylic resin particles include product number MG-351 (average primary particle diameter 1.0 μm) and product number BGK-001 (average primary particle diameter 1.0 μm) manufactured by Nippon Paint Industrial Coatings Co., Ltd. The organic filler (G) may also contain particles other than the above-mentioned rubber particles, acrylic resin particles, and cellulose particles. In this case, the organic filler (G) may contain particles having carboxyl groups. That is, the particles having a carboxyl group may be different from particles selected from rubber particles, acrylic resin particles, and cellulose particles.

[0119] The percentage of the organic filler (G) relative to the carboxyl group-containing resin (A) is preferably 1% by mass or more and 60% by mass or less. In this case, the thixotropy of the photosensitive resin composition is particularly likely to be enhanced, improving stability. In addition, the surface of the cured product is more likely to be more appropriately roughened by the oxidizing agent, further improving adhesion between the cured product and the conductor. This percentage is more preferably 3% by mass or more, and even more preferably 5% by mass or more. Furthermore, this percentage is more preferably 30% by mass or less, and even more preferably 17% by mass or less.

[0120] The photosensitive resin composition may contain a coupling agent. The coupling agent can further improve the dispersibility of silica (E), and when the photosensitive resin composition contains an organic filler (G), can also improve the dispersibility of the organic filler (G). It can also improve resolution. The coupling agent has, for example, at least one atom selected from the group consisting of a silicon atom, an aluminum atom, a titanium atom, and a zirconium atom. The coupling agent also has, for example, a functional group selected from the group consisting of an alkoxy group, an acyloxy group, and an alkoxide. It is particularly preferable that the coupling agent contains a silicon atom, i.e., the coupling agent preferably contains a silane coupling agent.

[0121] silica( E The percentage of the coupling agent relative to the total of the organic filler (G) and the binder (H) is more preferably 0.05% by mass or more and 5% by mass or less.

[0122] The photosensitive resin composition may contain melamine. In this case, when the cured product of the photosensitive resin composition is treated with an oxidizing agent, the cured product is less susceptible to excessive corrosion. Melamine is 2,4,6-triamino-1,3,5-triazine, which is commonly available commercially. The average particle size of melamine is preferably 20 μm or less, more preferably 15 μm or less. Uniform dispersion of melamine in the photosensitive resin composition facilitates coordination bonding of melamine with the metal element. This further improves the adhesion of the photosensitive resin composition. The lower limit of the average particle size of melamine is not particularly limited, but can be 0.01 μm or more. The average particle size of melamine is the cumulative 50% diameter (median diameter D50) calculated from the particle size distribution measured by laser diffraction / scattering when melamine is dispersed in the photosensitive resin composition.

[0123] When the photosensitive resin composition contains melamine, the percentage of melamine relative to the carboxyl group-containing resin (A) is preferably 0.1% by mass or more and 10% by mass or less. In this case, excessive corrosion when the cured product is treated with an oxidizing agent is more likely to be suppressed. This percentage is more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, and particularly preferably 1% by mass or more. Furthermore, this percentage is more preferably 9% by mass or less, even more preferably 8% by mass or less, and particularly preferably 6% by mass or less.

[0124] The photosensitive resin composition may contain an organic solvent. The organic solvent is used for the purposes of liquefying or varnish-forming the photosensitive resin composition, adjusting the viscosity, adjusting the coatability, adjusting the film-forming properties, etc.

[0125] The organic solvent may contain one or more compounds selected from the group consisting of linear, branched, secondary or polyhydric alcohols such as ethanol, propyl alcohol, isopropyl alcohol, hexanol, ethylene glycol, etc.; ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; petroleum-based aromatic mixed solvents such as the Swasol series (manufactured by Maruzen Petrochemical Co., Ltd.) and the Solvesso series (manufactured by Exxon Chemical Co., Ltd.); cellosolves such as cellosolve and butyl cellosolve; carbitols such as carbitol and butyl carbitol; propylene glycol alkyl ethers such as propylene glycol methyl ether; polypropylene glycol alkyl ethers such as dipropylene glycol methyl ether; acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, carbitol acetate, etc.; and dialkyl glycol ethers.

[0126] When the photosensitive resin composition contains an organic solvent, the amount of the organic solvent is preferably adjusted so that the organic solvent volatilizes quickly when the coating film formed from the photosensitive resin composition is dried, i.e., so that the organic solvent does not remain in the dried film. In particular, the proportion of the organic solvent relative to the entire photosensitive resin composition is preferably 0% by mass or more and 99.5% by mass or less, and more preferably 15% by mass or more and 60% by mass or less. Note that the suitable proportion of the organic solvent varies depending on the coating method, etc., so it is preferable to appropriately adjust the proportion depending on the coating method.

[0127] The photosensitive resin composition may further contain components other than the above components, as long as the effects of this embodiment are not impaired.

[0128] The photosensitive resin composition may contain at least one resin selected from the group consisting of blocked isocyanates such as tolylene diisocyanate, morpholine diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate blocked with caprolactam, oxime, malonic acid ester, etc.; butylated urea resin; various thermosetting resins other than those mentioned above; ultraviolet-curable epoxy (meth)acrylate; resins obtained by adding (meth)acrylic acid to epoxy resins such as bisphenol A type, phenol novolac type, cresol novolac type, and alicyclic type; and polymer compounds such as diallyl phthalate resin, phenoxy resin, urethane resin, melamine resin, and fluororesin.

[0129] The photosensitive resin composition may contain a curing agent for curing the epoxy compound (D). The curing agent may contain at least one component selected from the group consisting of imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole; 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 hydrazide and sebacic acid hydrazide; phosphorus compounds such as triphenylphosphine; acid anhydrides; phenols; mercaptans; Lewis acid amine complexes; and onium salts. Commercially available products of these components include, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, and 2P4MHZ (all trade names of imidazole-based compounds) manufactured by Shikoku Chemical Industries, Ltd., and U-CAT3503N and UCAT3502T (all trade names of dimethylamine-blocked isocyanate compounds), DBU, DBN, U-CATSA102, and U-CAT5002 (all bicyclic amidine compounds and salts thereof) manufactured by San-Apro Co., Ltd.

[0130] The photosensitive resin composition may contain an adhesion promoter, such as guanamine derivatives such as acetoguanamine (2,4-diamino-6-methyl-1,3,5-triazine) and benzoguanamine (2,4-diamino-6-phenyl-1,3,5-triazine), S-triazine derivatives such as 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine-isocyanuric acid adduct, and 2,4-diamino-6-methacryloyloxyethyl-S-triazine-isocyanuric acid adduct, silane coupling agents, and melamine derivatives.

[0131] The photosensitive resin composition may contain a rheology control agent. The rheology control agent facilitates optimizing the viscosity of the photosensitive resin composition. Examples of rheology control agents include urea-modified medium-polarity polyamide (Big Chemie Japan Co., Ltd., product numbers BYK-430 and BYK-431), polyhydroxycarboxylic acid amide (Big Chemie Japan Co., Ltd., product number BYK-405), modified urea (Big Chemie Japan Co., Ltd., product numbers BYK-410, BYK-411, and BYK-420), polymeric urea derivative (Big Chemie Japan Co., Ltd., product number BYK-415), urea-modified urethane (Big Chemie Japan Co., Ltd., product number BYK-425), polyurethane (Big Chemie Japan Co., Ltd., product number BYK-428), castor oil wax, polyethylene wax, polyamide wax, bentonite, kaolin, and clay.

[0132] The photosensitive resin composition may contain at least one component selected from the group consisting of a curing accelerator; a colorant; a copolymer of silicone, acrylate, or the like; a leveling agent; a thixotropic agent; a polymerization inhibitor; an antihalation agent; a flame retardant; an antifoaming agent; an antioxidant; a surfactant; and a polymer dispersant.

[0133] The photosensitive resin composition of this embodiment can be prepared by an appropriate method. For example, the photosensitive resin composition can be prepared by mixing and stirring the raw materials of the photosensitive resin composition. Alternatively, the photosensitive resin composition may be prepared by kneading using an appropriate kneading method, such as a three-roll mill, a ball mill, or a sand mill. When the raw materials contain liquid components, low-viscosity components, etc., the photosensitive resin composition may be prepared by first kneading the raw materials excluding the liquid components, low-viscosity components, etc. to prepare a mixture, and then adding and mixing the liquid components, low-viscosity components, etc. to the resulting mixture. When the photosensitive resin composition contains a solvent, some or all of the solvent may be first mixed among the raw materials, and then mixed with the remaining raw materials.

[0134] A printed wiring board containing a cured product of a photosensitive resin composition and a method for producing the same will be described.

[0135] The printed wiring board includes at least one of an interlayer insulating layer containing a cured product of a photosensitive resin composition and a solder resist layer containing a cured product of a photosensitive resin composition.

[0136] A printed wiring board 11 having an interlayer insulating layer 7 containing a cured product of a photosensitive resin composition will be described in detail with reference to FIGS. 1A to 1E.

[0137] When manufacturing a printed wiring board 11, for example, a photosensitive resin composition and a substrate 1 are prepared. The substrate 1 includes an insulating layer 2 and a second conductor layer 3 overlapping the insulating layer 2. An interlayer insulating layer 7 is formed on the substrate 1 from the photosensitive resin composition by photolithography. That is, a film 4 formed from the photosensitive resin composition is overlaid on the substrate 1 so as to cover the second conductor layer 3, and a negative pattern region of the film 4 including the pattern of via holes 6 is exposed to light, followed by development using an alkaline aqueous solution. This produces the interlayer insulating layer 7 and the via holes 6 penetrating the interlayer insulating layer 7.

[0138] Specifically, for example, first, a substrate 1 is prepared as shown in Fig. 1A. The substrate 1 includes an insulating layer 2 and a second conductor layer 3. The second conductor layer 3 is a conductor wiring.

[0139] A photosensitive resin composition is applied to a substrate 1 and then dried as necessary to produce a film 4 covering the second conductor layer 3, as shown in FIG. 1B. The method for applying the photosensitive resin composition is selected from the group consisting of, for example, a dipping method, a spraying method, a spin coating method, a roll coating method, a curtain coating method, and a screen printing method. When drying the photosensitive resin composition, the photosensitive resin composition is heated at a temperature of, for example, 60°C or higher and 130°C or lower.

[0140] The coating 4 may be produced by overlaying a dry film containing a photosensitive resin composition on the substrate 1. The dry film is formed on the support by applying a photosensitive resin composition to a suitable support, such as a polyester support, and then drying it. This results in a supported dry film comprising a dry film and a support that supports the dry film. The dry film in this supported dry film is overlaid on the substrate 1 so as to cover the second conductor layer 3, and then pressure is applied to the dry film and the substrate 1. This results in the coating 4 made of the dry film being overlaid on the substrate 1.

[0141] Next, the film 4 is exposed to light. For example, a negative pattern region of the film 4 including the pattern of the via holes 6 is exposed. In this case, for example, ultraviolet light is irradiated onto the film 4 through a negative mask. The negative mask has exposed areas that transmit ultraviolet light and non-exposed areas that block ultraviolet light, and the pattern of the non-exposed areas includes the pattern of the via holes 6. The negative mask is, for example, a photo tool such as a mask film or a dry plate. The source of ultraviolet light is, for example, selected from the group consisting of a chemical lamp, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a YAG laser, an LED, a xenon lamp, and a metal halide lamp.

[0142] When the coating 4 is made from a dry film, the coating 4 is exposed to light, for example, after the support is peeled off from the coating 4 in advance. Alternatively, the coating 4 may be exposed by irradiating the coating 4 with ultraviolet light passing through the support while the support is still superimposed on the coating 4, and then the support may be peeled off from the exposed coating 4.

[0143] As the exposure method, a method other than the method using a negative mask may be employed. For example, the coating 4 may be exposed by a direct writing method in which ultraviolet light emitted from a light source is irradiated only onto the portions of the coating 4 that are to be exposed. Light sources used in the direct writing method are selected from the group consisting of, for example, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a YAG laser, an LED, g-line (436 nm), h-line (405 nm), i-line (365 nm), and a combination of two or more of g-line, h-line, and i-line.

[0144] Next, the film 4 is developed with an alkaline aqueous solution to form an interlayer insulating layer 7 having a via hole 6. By subjecting the film 4 to a development process, the uncured portion 5 of the film 4 shown in FIG. 1C is removed, thereby forming a via hole 6 as shown in FIG. 1D. An appropriate developer can be used for the development process depending on the composition of the photosensitive resin composition. The developer can be, for example, an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide, or an organic amine. More specifically, the alkaline aqueous solution contains at least one component selected from the group consisting of sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, and lithium hydroxide. The solvent in the alkaline aqueous solution can be water alone or a mixture of water and a hydrophilic organic solvent such as a lower alcohol. The organic amine can contain at least one component selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine.

[0145] The alkaline aqueous solution preferably contains at least one of an alkali metal salt and an alkali metal hydroxide, and particularly preferably contains sodium carbonate, which can improve the working environment and reduce the burden of waste disposal.

[0146] The photosensitive resin composition according to this embodiment has good developability, so that uncured residue of the photosensitive resin composition is unlikely to remain at the bottom of the via hole 6 after development.

[0147] Subsequently, the developed coating 4 may be thermally cured by heating. The heating conditions are, for example, a heating temperature in the range of 120°C to 200°C and a heating time in the range of 20 minutes to 300 minutes. By thermally curing the coating 4 in this manner, the strength, hardness, chemical resistance, and other properties of the interlayer insulating layer 7 are improved.

[0148] If necessary, the coating 4 may be further irradiated with ultraviolet light either before or after heating, or both. In this case, the photo-curing of the coating 4 can be further promoted.

[0149] As a result of the above, an interlayer insulating layer 7 made of a cured product of the photosensitive resin composition is provided on the substrate 1.

[0150] Next, the first conductor layer 8 and the via conductor 9 are fabricated. However, before that, it is preferable to roughen the inner surface of the via hole 6 and the outer surface of the interlayer insulating layer 7 by treating them with an oxidizing agent. As the oxidizing agent, a desmear solution used in a general desmear treatment can be used. Such an oxidizing agent contains at least one permanganate selected from the group consisting of sodium permanganate and potassium permanganate.

[0151] Next, a first conductor layer 8, which is a conductor wiring, can be formed on the interlayer insulating layer 7 by a known method such as an additive process, and a via conductor 9 can be formed in the via hole 6. As a result, a printed wiring board 11 is obtained, which includes the first conductor layer 8, the second conductor layer 3, the interlayer insulating layer 7, the via hole 6, and the via conductor 9, as shown in FIG. 1E. Note that in FIG. 1E, the via conductor 9 is a film that covers the inside of the via hole 6, but the via conductor 9 may also fill the entire inside of the via hole 6.

[0152] In this embodiment, when the surface of the interlayer insulating layer 7 is treated with an oxidizing agent, the surface of the interlayer insulating layer 7 is not excessively corroded and fine irregularities are easily formed, which improves the adhesion between the interlayer insulating layer 7 and the first conductor layer 8 and via conductors 9.

[0153] A printed wiring board having a solder resist layer containing a cured product of a photosensitive resin composition will be described in detail.

[0154] When manufacturing a printed wiring board, for example, a core material is first prepared. The core material includes, for example, at least one insulating layer and at least one conductor wiring. A solder resist layer is formed on the core material from a photosensitive resin composition by photolithography. That is, a film is formed from the photosensitive resin composition on the surface of the core material on which the conductor wiring is provided. Examples of methods for forming the film include a coating method and a dry film method. The coating method and the dry film method can be the same as those used to form the interlayer insulating layer. The film is partially cured by exposure to light. The exposure method can also be the same as that used to form the interlayer insulating layer. Next, the film is subjected to a development process to remove the unexposed portions of the film, leaving the exposed portions of the film on the core material. Next, the film on the core material is thermally cured by heating. The development method and heating method can also be the same as those used to form the interlayer insulating layer. If necessary, the film may be further irradiated with ultraviolet light either before or after heating. In this case, the photocuring of the coating can be further advanced.

[0155] The thickness of the solder resist layer is not particularly limited, but may be 3 μm or more and 50 μm or less.

[0156] As a result of the above, a solder resist layer made of a cured product of the photosensitive resin composition is provided on the core material. This results in a printed wiring board having a core material including an insulating layer and conductor wiring thereon, and a solder resist layer that partially covers the surface of the core material on which the conductor wiring is provided. As with the interlayer insulating layer, the solder resist layer may be surface-treated with an oxidizing agent to roughen the surface of the solder resist layer. This improves adhesion between the solder resist layer and the conductors that make up the conductor wiring, solder, etc. [Example]

[0157] Specific examples of the present embodiment will be presented below, but the present embodiment is not limited to the following examples.

[0158] 1. Synthesis of carboxyl group-containing resin (1) Synthesis Example A-1: ​​Synthesis of resin having a bisphenolfluorene skeleton Into a four-neck flask equipped with a reflux condenser, thermometer, air inlet tube, and stirrer, 250 parts by mass of a bisphenol fluorene epoxy compound (an epoxy compound represented by formula (2), where R1 to R8 in formula (2) are all hydrogen and have an epoxy equivalent of 250 g / eq), 72 parts by mass of acrylic acid, 1.5 parts by mass of triphenylphosphine, 0.2 parts by mass of methylhydroquinone, 60 parts by mass of propylene glycol monomethyl ether acetate, and 140 parts by mass of diethylene glycol monoethyl ether acetate were added. A mixture was prepared by stirring these mixtures under air bubbling. This mixture was heated in the flask at 115°C for 12 hours while stirring under air bubbling. This produced a solution of the intermediate. Next, 60.8 parts by weight of 1,2,3,6-tetrahydrophthalic anhydride, 58.8 parts by weight of 3,3',4,4'-biphenyltetracarboxylic dianhydride, and 38.7 parts by weight of propylene glycol monomethyl ether acetate were added to the intermediate solution in the flask. The mixture was heated at 115°C for 6 hours with stirring under air bubbling, and then heated at 80°C for 1 hour with stirring under air bubbling. This yielded a solution of carboxyl group-containing resin A-1 (solid content 65% by weight). The polydispersity index (Mw / Mn) of the carboxyl group-containing resin A-1 was 2.15, the weight-average molecular weight (Mw) was 3096, and the acid value was 105 mgKOH / g.

[0159] (2) Synthesis Example A-2: Synthesis of resin having biphenyl novolac skeleton A mixture was prepared by adding 288 parts by mass of biphenyl novolac epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product number NC-3000-H, epoxy equivalent 288 g / eq), 155 parts by mass of diethylene glycol monoethyl ether acetate, 0.2 parts by mass of methylhydroquinone, 72 parts by mass of acrylic acid, and 3 parts by mass of triphenylphosphine to a four-neck flask equipped with a reflux condenser, thermometer, air inlet, and stirrer. This mixture was heated in the flask at 115°C for 12 hours while stirring under air bubbling. This produced a solution of the intermediate.

[0160] Next, 91.2 parts by mass of tetrahydrophthalic anhydride and 90 parts by mass of diethylene glycol monoethyl ether acetate were added to the intermediate solution in the flask, and the mixture was heated at 90°C for 4 hours while stirring under air bubbling. This produced a solution of carboxyl group-containing resin A-2 (solid content 65% by mass). The weight-average molecular weight of the carboxyl group-containing resin A-2 was 8120 and the acid value was 76 mgKOH / g.

[0161] 2. Preparation of photosensitive resin composition Among the raw materials, the powder raw materials and the carboxyl group-containing resin were kneaded in advance using a triple roll, and then the remaining raw materials were blended and stirred and mixed in a flask at 35°C to obtain a photosensitive resin composition.

[0162] In the table, "Raw material (solid content) / mass parts" indicates the amount of raw material blended. If the raw material contains a solvent, the amount of raw material blended is the amount of solid content in the raw material excluding the solvent. Details of the raw materials are as follows. In addition, "E / A" in the table indicates the equivalent of epoxy groups in the epoxy compound per equivalent of carboxyl groups in the carboxyl group-containing resin in the raw material. Photopolymerization initiator A: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, manufactured by BASF, product number Irgacure TPO. Photopolymerization initiator B: 1-hydroxy-cyclohexyl-phenyl-ketone, manufactured by BASF, product number Irgacure 184. Photopolymerization initiator C: 4,4'-bis(diethylamino)benzophenone. Photopolymerization initiator D: 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, manufactured by BASF, product number Irgacure 907. Photopolymerizable compound A: tricyclodecane dimethanol diacrylate. Photopolymerizable compound B: trimethylolpropane triacrylate. Epoxy compound A: biphenyl-type crystalline epoxy resin, product number YX-4000 manufactured by Mitsubishi Chemical Corporation, melting point 105°C, epoxy equivalent weight 187g / eq. Epoxy compound B: bisphenol-type crystalline epoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd., product number YSLV-80XY, melting point 75 to 85°C, epoxy equivalent 192 g / eq. Blocked isocyanate compound A: Duranate MF-B60B manufactured by Asahi Kasei Corporation. Hexamethylene diisocyanate-type methyl ethyl ketone oxime-blocked isocyanate compound, n-butyl acetate-n-butanol solution. Solid content: 60% by mass. Curing temperature: 120°C or higher. Blocked isocyanate compound B: Duranate SBB-70P manufactured by Asahi Kasei Corporation. A propylene glycol monomethyl ether acetate solution of a blocked isocyanate compound with a biuret base structure and a 1,3-dimethylpyrazole block structure. Solid content: 70% by mass. Curing temperature: 110°C or higher. Blocked isocyanate compound C: Duranate SBN-70D manufactured by Asahi Kasei Corporation. A solution of blocked isocyanate, a pyrazole derivative of 1,6-hexamethylene diisocyanate, in dipropylene glycol monomethyl ether. Solid content: 70% by mass. Curing temperature: 110°C or higher. Blocked isocyanate compound D: Duranate 17B-60P manufactured by Asahi Kasei Corporation. A propylene glycol monomethyl ether acetate solution of a blocked isocyanate compound having a biuret structure as the parent structure and an oxime ester structure as the block structure. Solid content: 60% by mass. Curing temperature: 130°C or higher. Isocyanate compound: Asahi Kasei Corporation, product number Duranate TPA-100. Isocyanate prepolymer with an isocyanurate structure. Solid content: 100% by mass. Isocyanate group content: 23% by mass. - Dispersion of silica A: Product number SSP-CM1 manufactured by Admatechs Co., Ltd. Slurry containing silica treated with phenylsilane and having an average particle size of 0.5 μm and methyl ethyl ketone. Solid content: 70% by mass. Dispersion of Silica B: Product number SC2050-MTX manufactured by Admatechs Co., Ltd. Slurry containing silica with an average particle size of 0.5 μm treated with phenylaminosilane (product number KBM-573 manufactured by Shin-Etsu Chemical Co., Ltd.) and methyl ethyl ketone. Solid content: 70% by mass. - Dispersion of Silica C: Product number SC2050-MNU manufactured by Admatechs Co., Ltd. Slurry containing silica treated with vinylsilane and having an average particle size of 0.5 μm and methyl ethyl ketone. Solid content: 70% by mass. Dispersion of Silica D: Product number SC2050-MB manufactured by Admatechs Co., Ltd. Slurry containing silica treated with epoxy silane and having an average particle size of 0.5 μm and methyl ethyl ketone. Solid content: 70% by mass. - Dispersion of Silica E: Product number 5SQ-CM2 manufactured by Admatechs Co., Ltd. Slurry containing untreated silica with an average particle size of 0.5 μm and methyl ethyl ketone. Solid content: 70% by mass. -Solvent dispersion of silica sol A: Product number MEK-EC-2130Y manufactured by Nissan Chemical Co., Ltd. Dispersion liquid containing silica sol with an average particle size of 12 nm and methyl ethyl ketone. Solid content: 30% by mass. -Solvent dispersion of silica sol B: Product number MEK-AC-4130Y manufactured by Nissan Chemical Co., Ltd. Dispersion liquid containing silica sol with an average particle size of 45 nm and methyl ethyl ketone. Solid content: 30% by mass. Dispersion of organic filler A: XER-91-MEK manufactured by JSR Corporation. Dispersion containing cross-linked rubber (NBR) with an average particle size of 0.07 μm and an acid value of 10.0 mg KOH / g and methyl ethyl ketone. Solid content: 15% by mass. Dispersion of organic filler B: Mitsubishi Gas Chemical Company, Inc., product number OPE-2St 1200. Dispersion containing toluene and a vinylbenzyl-modified polyphenylene ether oligomer having a number average molecular weight of 1187 and a vinyl group equivalent of 590 g / eq. Solid content: 65% by mass. -Antioxidant: Irganox 1010 manufactured by BASF Japan Ltd. -Melamine: 2,4,6-triamino-1,3,5-triazine. Average particle size 5 μm. Coupling agent: 3-glycidoxypropyltrimethoxysilane. -Surfactant: DIC Corporation, product number Megafac F-477. -Solvent: methyl ethyl ketone.

[0163] 3. Preparation of test pieces (1) Preparation of test pieces 1 Test pieces for carrying out the tests (1) to (8) in "4. Evaluation Tests" below were prepared as follows.

[0164] The photosensitive resin composition was applied to a polyethylene terephthalate film using an applicator and then dried by heating at 90°C for 30 minutes to form a 30 μm-thick dry film on the film. A glass epoxy copper-clad laminate (FR-4 type) with a 17.5 μm-thick copper foil was prepared. Interdigital electrodes with a line width / space width of 30 μm / 30 μm were formed on this glass epoxy copper-clad laminate using a subtractive method to form a core material. The surface of the conductor wiring of this core material, approximately 1 μm thick, was dissolved and removed using an etching agent (product number CZ-8101, manufactured by MEC Co., Ltd.), thereby roughening the conductor wiring. A dry film was heat-laminated onto this core material using a vacuum laminator, covering the conductor wiring while the film was still overlapping. The heat lamination conditions were 0.5 MPa, 80°C, and 1 minute. This formed a coating of the dry film on the core material. Next, to expose the coating, a negative mask having an unexposed area with a pattern including circular shapes with diameters of 100 μm, 80 μm, and 60 μm was placed directly on a film overlapping the coating, and the coating was exposed to 300 mJ / cm 2 2 The film was irradiated with ultraviolet light through the film under the conditions shown above. After the exposure, the film was peeled off from the dry film (coating), and the coating was then subjected to a development process. For the development process, a 1% Na2CO3 aqueous solution at 30°C was sprayed onto the coating at a spray pressure of 0.2 MPa for 90 seconds. Next, pure water was sprayed onto the coating at a spray pressure of 0.2 MPa for 90 seconds. This removed the unexposed portions of the coating, forming via holes in the coating. Next, the coating was heated at 180°C for 120 minutes. This formed a layer made of a cured product of the photosensitive resin composition (which can also be said to be a cured product of the dry film) on the core material. This resulted in the production of a test piece.

[0165] (2) Preparation of test pieces 2 Test pieces for conducting the tests (9) and (10) in "4. Evaluation Tests" below were prepared as follows.

[0166] The photosensitive resin composition was applied to a polyethylene terephthalate film using an applicator, and then dried by heating at 90°C for 30 minutes, forming a 50 μm-thick dry film on the film. This dry film, while still overlapping the film, was heat-laminated onto the entire surface of a Teflon (registered trademark) film using a vacuum laminator. The heat lamination conditions were 0.5 MPa, 80°C, and 1 minute. This resulted in a 50 μm-thick dry film coating on the Teflon film. Next, to expose the coating, a mask with a 3 mm × 85 mm rectangular exposure area was placed directly on the film overlapping the coating, and 300 mJ / cm was applied to the coating through the mask and the film. 2 The film was irradiated with ultraviolet light under the following conditions. After exposure, the film was peeled off from the dry film (coating). Next, to develop the coating, a 1% Na2CO3 aqueous solution at 30°C was sprayed onto the coating at a spray pressure of 0.2 MPa for 90 seconds. The coating was then washed by spraying pure water onto the coating at a spray pressure of 0.2 MPa for 90 seconds. The coating was then heated at 180°C for 120 minutes. This formed a cured product of the photosensitive resin composition (cured product of the dry film) on the Teflon film. This cured product was peeled off from the Teflon film to obtain a test piece.

[0167] 4.Evaluation Test (1) Developability In the process of preparing the test pieces, the unexposed portions of the coating after development were observed, and the results were evaluated as follows. A: All unexposed areas of the film have been removed. B: A portion of the unexposed area of ​​the coating remained on the core material. After an additional 30 seconds of development (1% Na2CO3 aqueous solution, 0.2 MPa), the unexposed area was completely removed. C: Part of the unexposed area of ​​the coating remained on the core material. Even after an additional 30-second development (1% Na2CO3 aqueous solution, 0.2 MPa), part of the unexposed area remained on the core material. D: Could not develop.

[0168] If the evaluation was "D", the tests from (2) onwards below were not conducted.

[0169] (2) Openness A commercially available swelling treatment liquid (Swelling Dip Securiganth P, manufactured by Atotech Japan Co., Ltd.) was prepared as a swelling liquid for desmearing. The cured test piece was immersed in this swelling treatment liquid at 60°C for 5 minutes and then rinsed with hot water. Next, a desmear liquid containing potassium permanganate (Concentrate Compact CP, manufactured by Atotech Japan Co., Ltd.) was prepared as an oxidizing agent. The cured material was immersed in the oxidizing agent at 80°C for 10 minutes to roughen the surface of the cured material. Next, the cured material was rinsed with hot water and then immersed in a neutralizing solution (Reduction Solution Securiganth P, manufactured by Atotech Japan Co., Ltd.) at 40°C for 5 minutes to remove oxidizing agent residue from the surface of the cured material. The cured material was then rinsed with water.

[0170] After the above treatment, the cured test pieces were inspected for holes corresponding to the patterns of 100 μm, 80 μm, and 60 μm diameters on the mask used to prepare the cured test pieces, and the results were evaluated as follows. A: The holes corresponding to the pattern with a diameter of 100 μm, the holes corresponding to the pattern with a diameter of 80 μm, and the holes corresponding to the pattern with a diameter of 60 μm are all open. B: Holes corresponding to the pattern with a diameter of 100 μm and holes corresponding to the pattern with a diameter of 80 μm were open, but holes corresponding to the pattern with a diameter of 60 μm were not open. C: The holes corresponding to the 100 μm diameter pattern were opened, but the holes corresponding to the 80 μm diameter pattern and the 60 μm diameter pattern were not opened. D: None of the holes corresponding to the pattern with a diameter of 100 μm, the holes corresponding to the pattern with a diameter of 80 μm, and the holes corresponding to the pattern with a diameter of 60 μm were open.

[0171] (3) Plating resistance During the preparation of the test piece, a portion of the conductor wiring was left uncovered by the layer of the cured product. A nickel plating layer was formed on a portion of the conductor wiring in this test piece using a commercially available electroless nickel plating bath, and then a gold plating layer was formed using a commercially available electroless gold plating bath. This resulted in a metal layer consisting of a nickel plating layer and a gold plating layer. The layer of the cured product and the metal layer were visually observed. Furthermore, a cellophane adhesive tape peel test was performed on the layer of the cured product. The results were evaluated as follows: A: No abnormalities were observed in the appearance of the layer made of the cured product and the metal layer, and the layer made of the cured product did not peel off in a cellophane adhesive tape peeling test. B: Discoloration was observed in the layer made of the cured product, but the layer made of the cured product did not peel off in a cellophane adhesive tape peeling test. C: Significant discoloration was observed in the layer made of the cured product, but the layer made of the cured product did not peel off in a cellophane adhesive tape peeling test. D: Lifting of the layer made of the cured product was observed, and peeling of the layer made of the cured product occurred in a cellophane adhesive tape peeling test.

[0172] (4) Insulation The printed wiring board was exposed to a test environment of 130°C and 85% RH for 200 hours while a bias voltage of DC 5V was applied to the conductor wiring (comb-shaped electrodes) of the test piece. Under this test environment, the electrical resistance between the comb-shaped electrodes of the layer made of the cured product was constantly measured, and the results were evaluated according to the following criteria. A: From the start of the test until 200 hours have passed, the electrical resistance value is always 10 6 Maintained above Ω. B: The electrical resistance value is always 10 for 150 hours from the start of the test. 6 Ω or more, but the electrical resistance value was 10 6 It became less than Ω. C: The electrical resistance value is always 10 6 The electrical resistance was maintained at 10 Ω or more, but within 150 hours from the start of the test, the electrical resistance reached 10 6It became less than Ω. D: The electrical resistance value is 10 6 It became less than Ω.

[0173] (5) PCT (Pressure Cooker Test) The test piece was left in an environment of 121°C and 100% RH for 100 hours, and then the appearance of the layer made of the cured product was evaluated according to the following criteria. A: No abnormalities were observed in the layer made of the cured material. B: Slight discoloration was observed in the layer made of the cured product. C: Significant discoloration was observed in the layer made of the cured product. D: Significant discoloration was observed in the layer made of the cured material, and swelling occurred in some areas.

[0174] (6) Thermal shock resistance A water-soluble flux (London Chemical Company, product number LONCO 3355-11) was applied to the cured layer of the test piece, and the test piece was then immersed in a molten solder bath at 280°C for 30 seconds, followed by immersion in water at 25°C for 30 seconds, after which the appearance of the cured layer was observed. This treatment was repeated five times, and the thermal shock resistance was evaluated as follows: A: Even after five treatments, no abnormalities such as swelling, peeling, or cracks were observed in the layer made of the cured product. B: After five treatments, abnormalities such as swelling, peeling, and cracks were observed in the layer made of the cured material, but after four treatments, no abnormalities such as swelling, peeling, and cracks were observed in the layer made of the cured material. C: After four treatments, abnormalities such as swelling, peeling, and cracks were observed in the layer made of the cured material, but after three treatments, no abnormalities such as swelling, peeling, and cracks were observed in the layer made of the cured material. D: Within three treatments, abnormalities such as swelling, peeling, and cracks were observed in the layer made of the cured material.

[0175] (7) Roughening resistance (evaluation of the thickness of the cured layer after roughening) The layer made of the cured product in the test piece was treated with a swelling treatment solution, an oxidizing agent, and a neutralizing agent in the same manner as in "(2) Openability" above, to roughen the surface of this layer.

[0176] The surface of this layer made of the cured product was observed, and then the layer made of the cured product was subjected to ultrasonic cleaning (42 kHz, 30 seconds) and then observed again.

[0177] From the results, the resistance of the cured product to oxidizing agents was evaluated according to the following criteria. A: No whitening was observed on the surface of the layer made of the cured product, and no significant change was observed in the uneven shape of the surface even after ultrasonic cleaning. B: No whitening was observed on the surface of the layer made of the cured material, but a small amount of silica was observed to have been removed from the surface after ultrasonic cleaning. C: A slight whitening phenomenon was observed on the surface of the layer made of the cured material, and silica was confirmed to have been removed from the surface after ultrasonic cleaning. D: The surface of the layer made of the cured material was strongly whitened, and detachment of silica from the surface was confirmed after ultrasonic cleaning.

[0178] (8) Adhesion to copper plating layer The layer made of the cured product in the test piece was treated with a swelling treatment solution, an oxidizing agent, and a neutralizing agent in the same manner as in "(2) Openability" above, to roughen the surface of this layer.

[0179] Subsequently, an initial wiring was formed on the layer of the cured product by electroless copper plating using a commercially available chemical solution, and the test piece was then heated at 150°C for 1 hour. 2 A copper plating layer was formed by depositing copper to a thickness of 33 μm on the initial wiring by electrolytic copper plating treatment under the conditions of 1. Then, the test piece was heated at 180° C. for 30 minutes.

[0180] During the process of producing the copper plating layer, the occurrence of blisters was confirmed during heating after electroless copper plating and heating after electrolytic copper plating. The adhesion strength between the copper plating layer and the cured product was measured according to JIS C6481. The measurement was performed four times, and the average value was calculated. The results were evaluated as follows: A: No blisters were observed when heating after electroless copper plating and when heating after electrolytic copper plating, and the average adhesion strength was 0.40 kN / m or more. B: No blisters were observed when heated after electroless copper plating or when heated after electrolytic copper plating, and the average adhesion strength was 0.30 kN / m or more and less than 0.4 kN / m. C: No blisters were observed when heating after electroless copper plating or when heating after electrolytic copper plating, and the average adhesion strength was less than 0.3 kN / m. D: Blisters were observed when heating was performed after electroless copper plating or when heating was performed after electrolytic copper plating.

[0181] (9) Dielectric constant The relative permittivity of the test piece was measured at a frequency of 10 GHz using a permittivity measuring device (ADMS01O, manufactured by AET Corporation) by the cavity resonator method in accordance with JIS C2565. The results were evaluated as follows. A: The relative dielectric constant is less than 3.2. B: The relative dielectric constant is 3.2 or more and less than 3.5. C: The relative dielectric constant is 3.5 or more and less than 3.8. D: The relative dielectric constant is 3.8 or more.

[0182] (10) Dielectric tangent The dielectric loss tangent (tanδ) of the test piece was measured at a frequency of 10 GHz using a dielectric constant measuring device (manufactured by AET Corporation, ADMS01O) by the cavity resonator method in accordance with JIS C2565. The results were evaluated as follows. A: The dielectric loss tangent is less than 0.008. B: The dielectric loss tangent is 0.008 or more and less than 0.01. C: The dielectric loss tangent is 0.01 or more and less than 0.012. D: The dielectric tangent is 0.012 or more.

[0183] [Table 1]

[0184] [Table 2]

[0185] [Table 3]

Claims

1. a carboxyl group-containing resin (A); a photopolymerization initiator (B), photopolymerizable compound (C), Epoxy compound (D), Silica (E) whose percentage relative to the carboxyl group-containing resin (A) is 50% by mass or more and 300% by mass or less and whose surface is treated with a silane coupling agent; and The composition contains a blocked isocyanate compound (F) in an amount of 21% by mass or more and 100% by mass or less relative to the carboxyl group-containing resin (A), The photopolymerizable compound (C) contains a compound (C1) having a tricyclodecane skeleton, Photosensitive resin composition.

2. The carboxyl group-containing resin (A) contains a carboxyl group-containing resin (A1) having an aromatic ring, The photosensitive resin composition according to claim 1 .

3. The carboxyl group-containing resin (A) contains a carboxyl group-containing resin (A11) having a bisphenolfluorene skeleton, The photosensitive resin composition according to claim 1 or 2.

4. The photopolymerization initiator (B) contains an acylphosphine oxide-based photopolymerization initiator (B1). The photosensitive resin composition according to claim 1 .

5. The equivalent weight of the epoxy group of the epoxy compound (D) is 1 / 2 of the carboxyl group-containing resin (A). a ratio of 0.1 or more to less than 1 relative to 1 equivalent of a carboxyl group; The photosensitive resin composition according to claim 1 .

6. The epoxy compound (D) contains a crystalline epoxy compound (D1), The photosensitive resin composition according to claim 1 .

7. The blocked isocyanate compound (F) is a compound obtained by blocking an isocyanate compound with a blocking agent, and the isocyanate compound contains at least one compound selected from the group consisting of tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and polymers thereof. The photosensitive resin composition according to claim 1 .

8. The blocking agent contains at least one compound selected from the group consisting of an oxime compound, a lactam compound, a phenol compound, an alcohol compound, an amine compound, an active methylene compound, and a pyrazole compound. The photosensitive resin composition according to claim 7.

9. The silica (E) contains silica (E1) having an average particle size of 0.1 μm or more and 5 μm or less. The photosensitive resin composition according to claim 1 .

10. The composition further comprises an organic filler (G) containing at least one type of particle selected from the group consisting of rubber particles, acrylic resin particles having a carboxyl group, and cellulose particles having a carboxyl group. The photosensitive resin composition according to claim 1 .

11. The organic filler (G) has a reactive group. The photosensitive resin composition according to claim 10.

12. A photosensitive resin composition according to any one of claims 1 to 11, Dry film.

13. A photosensitive resin composition obtained by curing the photosensitive resin composition according to any one of claims 1 to 11. cured product.

14. An interlayer insulating layer comprising the cured product according to claim 13. Printed wiring board.

15. A solder resist layer comprising the cured product according to claim 13. Printed wiring board.

Images