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

Abstract

To provide a photosensitive resin composition containing a carboxyl group-containing resin, which facilitates achieving a low dielectric loss tangent in a cured product, allows the flexibility of the cured product to be easily maintained, and is resistant to excessive corrosion even when the cured product is 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), silica (E) whose percentage relative to the carboxyl group-containing resin (A) is 50 mass% or more and 300 mass% or less, the silica (E) being surface-treated with a silane coupling agent, and a blocked isocyanate compound (F) whose percentage relative to the carboxyl group-containing resin (A) is 21 mass% or more and 100 mass% or less. The silane coupling agent has a phenyl skeleton.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. Specifically, the present invention relates 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 including a solder resist layer or an interlayer insulating layer containing this cured product.

Background Art

[0002] Patent Document 1 discloses a curable resin composition in which the cured product has a low dielectric constant and a low dielectric tangent. Patent Document 1 discloses that the curable resin composition contains an alkali-soluble resin, an inorganic filler, a photocurable compound having no hydroxyl group and no carboxyl group, an adhesion promoter, and a photopolymerization initiator, that a blocked isocyanate is preferable as the adhesion promoter, and that the blending amount of the adhesion promoter is 0.01 to 20 parts by mass in terms of solid content with respect to 100 parts by mass of the (A) alkali-soluble resin.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the findings independently obtained by the inventors through research and development, when producing a solder resist layer, an interlayer insulating layer, etc. from a cured product of a resin composition containing a carboxyl group-containing resin, if an inorganic filler is blended to reduce the dielectric tangent, the cured product tends to become brittle. Further, when adjusting the roughness by treating the surface of the cured product with an oxidizing agent or the like in order to enhance the adhesion between the cured product, particularly the interlayer insulating layer and the conductor overlapping therewith, the inorganic filler easily falls off from the cured product, and therefore the cured product is easily corroded excessively by the oxidizing agent.

[0005] An object of the present invention is to provide a photosensitive resin composition containing a carboxyl group-containing resin, which is easy to lower the dielectric tangent of the cured product, easy to maintain the flexibility of the cured product, and not easily corroded excessively even when the cured product is treated with an oxidizing agent, a dry film containing this photosensitive resin composition, a cured product of this photosensitive resin composition, and a printed wiring board including a solder resist layer or an interlayer insulating layer containing this cured product.

Means for Solving the Problems

[0006] The photosensitive resin composition according to one aspect 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) having a percentage of 50% by mass or more and 300% by mass or less with respect to the carboxyl group-containing resin (A), and a blocked isocyanate compound (F) having a percentage of 21% by mass or more and 100% by mass or less with respect to the carboxyl group-containing resin (A).

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

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

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

[0010] The 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 containing a carboxyl group-containing resin, which is likely to reduce the dielectric tangent of the cured product, is likely to maintain the flexibility of the cured product, and is less likely to be excessively corroded even when the cured product is treated with an oxidizing agent, a dry film containing this photosensitive resin composition, a cured product of this photosensitive resin composition, and a printed wiring board including a solder resist layer or an interlayer insulating layer containing this cured product.

Brief Description of Drawings

[0012]

Figure 1

Embodiments for Carrying Out the Invention

[0013] Hereinafter, an embodiment of the present invention will be described. Note that the following embodiment is only one of various embodiments of the present invention. The following embodiment can be variously modified according to 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) with a percentage of 50% by mass or more and 300% by mass or less with respect to the carboxyl group-containing resin (A), and a blocked isocyanate compound (F) with a percentage of 21% by mass or more and 100% by mass or less with respect to the carboxyl group-containing resin (A).

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

[0016] The photosensitive resin composition contains silica (E), and when the percentage of silica (E) relative to the carboxyl group-containing resin (A) is 50% by mass or more, silica (E) can reduce the dielectric tangent of the cured product. Further, the photosensitive resin composition contains a blocked isocyanate compound (F), and when the percentage of the blocked isocyanate compound (F) 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) reacts with a hydroxyl group during the curing process of the photosensitive resin composition. Therefore, the hydroxyl group in the cured product (X) is reduced, and thereby the dielectric tangent of the cured product is further reduced. Further, the urethane bond generated by this reaction enhances the flexibility of the cured product. Also, the blocked isocyanate compound (F) easily binds to the hydroxyl groups on the surface of silica (E). Therefore, even 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.

[0017] Furthermore, the blocked isocyanate compound (F) can enhance the developability when producing a film such as a solder resist layer or an interlayer insulating layer from the photosensitive resin composition by photolithography. The reason is not fully clear, but 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. Therefore, it is presumed that the photosensitive resin composition is more likely to dissolve or disperse moderately in the developer. Also, since the blocked isocyanate compound (F) is protected by a blocking agent, it is less likely to react during the process of forming a film by photolithography. This is also presumed to contribute to the improvement of developability.

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

[0019] The carboxyl group-containing resin (A) can contain a component having a carboxyl group with an ethylenically unsaturated group. 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 enhanced. The carboxyl group-containing resin (A1) more preferably has any of a polycyclic aromatic ring 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 more likely to be enhanced.

[0021] The carboxyl group-containing resin (A) particularly preferably contains a carboxyl group-containing resin (A11) having a bisphenol fluorene skeleton. In this case, the heat resistance and electrical insulation of the cured product are particularly likely to be enhanced.

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

[0023]

Chemical formula

[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, but may also be an alkyl group having 1 to 5 carbon atoms or a halogen. Even if the hydrogen in the aromatic ring is substituted with a low-molecular-weight alkyl group or a halogen, it does not adversely affect the physical properties of the carboxyl group-containing resin (A11). Rather, in some cases, the heat resistance or flame retardancy of the cured product of the photosensitive resin composition containing the carboxyl group-containing resin (A11) is improved by the substitution.

[0025] The carboxyl group-containing resin (A11) is synthesized, for example, by reacting an epoxy compound (a1) having a bisphenol fluorene skeleton represented by the 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, for example, a structure represented by the following formula (2). In the formula (2), n is an integer, for example, within the range of 0 to 20. In order to appropriately control the molecular weight of the carboxyl group-containing resin (A11), it is more preferable that the average of n is within the range of 0 to 1. If the average of n is within the range of 0 to 1, an excessive increase in the molecular weight of the carboxyl group-containing resin (A11) is likely to be suppressed. Further, in the formula (2), R1 to R8 are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen.

[0027]

Chemical formula

[0028] The unsaturated group-containing carboxylic acid (a2) contains, for example, a compound having only 1 ethylenically unsaturated group in one molecule. More specifically, the unsaturated group-containing carboxylic acid (a2) is, 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, and contains at least one compound selected from the group consisting of these. Preferably, the unsaturated group-containing carboxylic acid (a2) contains acrylic acid. Further, when the unsaturated group-containing carboxylic acid (a2) contains acrylic acid, it is preferable that acrylic acid is contained in an amount of 50 mol% or more, more preferably 80 mol% or more, still more preferably 85 mol% or more, and particularly preferably 90 mol% or more in the unsaturated group-containing carboxylic acid (a2).

[0029] The epoxy compound (a1) and the unsaturated group-containing carboxylic acid (a2) can be reacted by an appropriate method. For example, the unsaturated group-containing carboxylic acid (a2) is added to a solvent solution of the epoxy compound (a1), and further a thermal polymerization inhibitor and a catalyst are added as necessary and stirred and mixed to obtain a reactive solution. By reacting this reactive solution by a conventional method, preferably at a temperature of 60°C or higher and 150°C or lower, more preferably 80°C or higher and 120°C or lower, an intermediate can be obtained. 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 can contain at least one component selected from the group consisting of hydroquinone, methyl hydroquinone, and hydroquinone monomethyl ether. The catalyst can contain at least one component selected from the group consisting of tertiary amines such as benzyldimethylamine and triethylamine, quaternary ammonium salts such as trimethylbenzylammonium chloride and methyltriethylammonium chloride, triphenylphosphine, and triphenylstibine.

[0030] It is particularly preferable that the catalyst contains triphenylphosphine. That is, in the presence of triphenylphosphine, it is preferable to react the epoxy compound (a1) with the unsaturated group-containing carboxylic acid (a2). 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 higher, or 97% or higher, or almost 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 can be suppressed, and the increase in the molecular weight of the intermediate and the gelation of the solution of the intermediate can be suppressed. Further, excessive coloring of the carboxyl group-containing resin (A11) as the final product can be suppressed.

[0032] When reacting the epoxy compound (a1) with the unsaturated group-containing carboxylic acid (a2), the amount of the unsaturated group-containing carboxylic acid (a2) relative to 1 mol of the epoxy group of the epoxy compound (a1) is preferably 0.8 mol or more and 1.2 mol or less. In this 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 of 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 the acid anhydride (a3). The acid anhydride (a3) 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. The acid dianhydride (a4) is, for example, 1,2,4,5-benzenetetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, methylcyclohexene tetracarboxylic dianhydride, tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, ethylene tetracarboxylic dianhydride, 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, glycerin bisanhydrotrimellitate monoacetate, ethylene glycol bisanhydrotrimellitate, 3,3',4,4'-diphenylsulfone tetracarboxylic 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 at least one compound selected from the group consisting of 3,3',4,4'-biphenyltetracarboxylic dianhydride. In particular, it is preferable that the acid dianhydride (a4) contains 3,3',4,4'-biphenyltetracarboxylic dianhydride. 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 suppressed, and the insulation reliability and plating resistance of the cured product can be improved.

[0036] The acid anhydride (a3) may contain a monoacid anhydride (a5). The monoacid anhydride (a5) is a compound having one acid anhydride group. The monoacid anhydride (a5) can contain a dicarboxylic acid anhydride. The monoacid anhydride (a5) contains, for example, one or more compounds selected from the group consisting of phthalic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, methyl succinic anhydride, maleic anhydride, citraconic anhydride, glutaric anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, and itaconic anhydride. In particular, it is preferable that the monoacid anhydride (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 insulation reliability and plating resistance of the cured product can be further improved. With respect to the entire monoacid anhydride (a5), 1,2,3,6-tetrahydrophthalic anhydride is preferably in the range of 20 mol% or more and 100 mol% or less, more preferably in the range of 40 mol% or more and 100 mol% or less, but is not limited thereto.

[0037] When reacting the intermediate with the acid anhydride (a3), an appropriate method can be adopted. For example, the acid anhydride (a3) is added to a solvent solution of the intermediate, and if necessary, a thermal polymerization inhibitor and a catalyst are further added and stirred and mixed to obtain a reactive solution. By reacting this reactive solution by a conventional method, preferably at a temperature of 60°C or higher and 150°C or lower, particularly preferably 80°C or higher and 120°C or lower, a carboxyl group-containing resin (A11) having a bisphenol fluorene skeleton is obtained. As the solvent, catalyst, and polymerization inhibitor, appropriate ones can be used, and the solvent, catalyst, and polymerization inhibitor used during the synthesis of the intermediate can also be used as they are.

[0038] The catalyst preferably contains triphenylphosphine in particular. That is, in the presence of triphenylphosphine, it is preferable to react the intermediate with the acid anhydride (a3). 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 almost 100% can be achieved.

[0039] When the acid anhydride (a3) contains the diacid anhydride (a4), the amount of the diacid anhydride (a4) is preferably 0.05 mol or more and 0.24 mol or less with respect to 1 mol of the epoxy group of the epoxy compound (a1). In this case, a carboxyl group-containing resin (A11) having a bisphenol fluorene skeleton with appropriately adjusted acid value and molecular weight can be easily obtained.

[0040] When the acid anhydride (a3) further contains the monoacid anhydride (a5), the amount of the monoacid anhydride (a5) is preferably 0.3 mol or more and 0.7 or less with respect to 1 mol of the epoxy group of the epoxy compound (a1). In this case, a carboxyl group-containing resin (A11) having a bisphenol fluorene skeleton with appropriately adjusted acid value and molecular weight can be easily obtained.

[0041] It is also preferable to react the intermediate with the acid anhydride (a3) under air bubbling. In this case, excessive molecular weight increase of the carboxyl group-containing resin (A11) having a bisphenol fluorene skeleton generated is suppressed, so that the developability of the photosensitive resin composition with an alkaline aqueous solution is particularly improved.

[0042] The carboxyl group-containing resin (A) may contain a carboxyl group-containing resin having no bisphenol fluorene skeleton (hereinafter, also referred to as carboxyl group-containing resin (A2)). The carboxyl group-containing resin (A) may contain at least one of the carboxyl group-containing resin (A11) and the carboxyl group-containing resin (A2).

[0043] The carboxyl group-containing resin (A2) can contain, for example, a carboxyl group-containing resin having a carboxyl group and no photopolymerizability (hereinafter referred to as the carboxyl group-containing resin (A2-1)). The carboxyl group-containing resin (A2-1) contains, 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 can contain compounds such as acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≈2) monoacrylate. The ethylenically unsaturated compound having a carboxyl group can also contain a reaction product of pentaerythritol triacrylate, pentaerythritol trimethacrylate, etc. 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, a linear or branched aliphatic or alicyclic (however, it may have a partial unsaturated bond in the ring) (meth)acrylate.

[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 the 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)), which is a reaction product of an intermediate that is a reaction product of an epoxy compound (x1) having two or more epoxy groups in one molecule and an ethylenically unsaturated compound (x2) with at least one compound (x3) selected from the group of polyvalent carboxylic acids and their anhydrides. The first resin (x) is obtained, for example, by adding the compound (x3) to an intermediate obtained by reacting an epoxy group in the epoxy compound (x1) with a carboxyl group in the ethylenically unsaturated compound (x2).

[0046] The epoxy compound (x1) can contain an appropriate epoxy compound such as a cresol novolak type epoxy compound, a phenol novolak type epoxy compound, or a biphenyl novolak type epoxy compound. In particular, the epoxy compound (x1) preferably contains at least one compound selected from the group consisting of a biphenyl novolak type epoxy compound and a cresol novolak type epoxy compound. In this case, the resin contained in the carboxyl group-containing resin (A1) having the above-mentioned aromatic ring can be obtained. The epoxy compound (x1) may contain only a biphenyl novolak type epoxy compound or may contain only a cresol novolak type epoxy compound.

[0047] The epoxy compound (x1) may contain a polymer of an ethylenically unsaturated compound (z). The ethylenically unsaturated compound (z) contains, for example, a compound (z1) having an epoxy group such as glycidyl (meth)acrylate, or further contains a compound (z2) having no 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) contains, for example, one or more compounds selected from the group consisting of polyvalent carboxylic acids such as phthalic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid, and anhydrides of these polyvalent carboxylic acids. In particular, the compound (x3) preferably contains at least one polyvalent carboxylic 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 the second resin (y)) which is a reaction product of a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group and 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 an ethylenically unsaturated compound having an epoxy group with a part of the carboxyl groups in the polymer. 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 compounds such as acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≈2) monoacrylate, pentaerythritol triacrylate, and pentaerythritol trimethacrylate. Examples of the ethylenically unsaturated compound having no carboxyl group include compounds such as 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, and (meth)acrylic acid esters of linear or branched aliphatic or alicyclic (wherein the ring may have a partial unsaturated bond) compounds. The ethylenically unsaturated compound having an epoxy group preferably contains glycidyl (meth)acrylate.

[0049] The carboxyl group-containing resin (A) preferably contains 25% by mass or more of the carboxyl group-containing resin (A1), more preferably 40% by mass or more, still more preferably 60% by mass or more, and particularly preferably 100% by mass. In this case, the heat resistance and insulation reliability of the cured product of the photosensitive resin composition can be particularly improved.

[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, still more preferably 60% by mass or more, and particularly preferably 100% by mass. In this case, excellent photosensitivity and developability with an alkaline aqueous solution of the photosensitive resin composition can be ensured. Further, the heat resistance and insulation 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 insulation 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 tends to be good. The weight average molecular weight of the carboxyl group-containing resin (A) is more preferably 900 or more and 60,000 or less, still more preferably 1200 or more and 10,000 or less, and particularly preferably 1400 or more and 5000 or less. The weight average molecular weight of the carboxyl group-containing resin (A) is calculated from the measurement results under the following conditions by, for example, gel permeation chromatography.

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

[0053] The carboxyl group-containing resin (A) preferably contains a component having 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. More preferably, the acid value is 70 mgKOH / g or more and 145 mgKOH / g or less, still 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) with respect to the solid content of the photosensitive resin composition is preferably 5% by mass or more and 85% by mass or less. This percentage is more preferably 10% by mass, still more preferably 20% by mass or more. Also, this percentage is more preferably 75% by mass or less, still more preferably 50% by mass or less.

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

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

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

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

[0059] The α-aminoalkylphenone-based photoinitiator can 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] The acylphosphine oxide-based photoinitiator (B1) can contain at least one component selected from the group consisting of monoacylphosphine oxide-based photoinitiators such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and 2,4,6-trimethylbenzoyl-ethyl-phenyl-phosphinate, and bisacylphosphine oxide-based photoinitiators such as bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and (2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide.

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

[0062] The photosensitive resin composition may further contain an appropriate photopolymerization accelerator, a sensitizer, and the like. For example, the photosensitive resin composition may contain hydroxyketones such as 1-hydroxy-cyclohexyl-phenyl-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, 2-hydroxy-2-methyl-1-phenyl-propan-1-one; benzoin and its alkyl ethers; acetophenones such as acetophenone and benzyldimethyl ketal; anthraquinones such as 2-methylanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diisopropylthioxanthone; benzophenones such as benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, bis(diethylamino)benzophenone; xanthones such as 2,4-diisopropylxanthone; α-hydroxyketones such as 2-hydroxy-2-methyl-1-phenyl-propan-1-one; and at least one component selected from the group consisting of compounds containing a nitrogen atom such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone. The photosensitive resin composition may contain an appropriate photopolymerization accelerator and a sensitizer such as a tertiary amine-based compound such as ethyl p-dimethylbenzoate, isoamyl p-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, etc. together with the photopolymerization initiator (B). The photosensitive resin composition may contain at least one of a photopolymerization initiator for visible light exposure and a photopolymerization initiator for near-infrared light exposure as needed. The photosensitive resin composition may contain a coumarin derivative such as 7-diethylamino-4-methylcoumarin, a carbocyanine dye-based compound, a xanthene dye-based compound, etc., which are sensitizers for laser exposure methods, together with the photopolymerization initiator (B).

[0063] The photoinitiator (B) preferably contains a hydroxyketone-based photoinitiator (B2) in addition to the acylphosphine oxide-based photoinitiator (B1). That is, the photosensitive resin composition preferably contains a hydroxyketone-based photoinitiator (B2). In this case, higher photosensitivity can be imparted to the photosensitive resin composition compared to the case where the hydroxyketone-based photoinitiator (B2) is not contained. Thereby, when the film formed from the photosensitive resin composition is irradiated with ultraviolet rays and cured, it becomes possible to sufficiently cure the film from its surface to the deep part. Examples of the hydroxyketone-based photoinitiator (B2) include 1-hydroxy-cyclohexyl-phenyl-ketone, methyl phenylglyoxylate, 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, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and the like.

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

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

[0066] The percentage of bis(diethylamino)benzophenone (B3) with respect to the acylphosphine oxide-based photoinitiator (B1) is preferably 0.5% by mass or more and 20% by mass or less. When bis(diethylamino)benzophenone (B3) is 0.5% by mass or more, the resolution becomes particularly high. Also, when bis(diethylamino)benzophenone (B3) is 20% by mass or less, the bis(diethylamino)benzophenone (B3) is less likely to inhibit the electrical insulation of the cured product of the photosensitive resin composition.

[0067] The percentage of the photoinitiator (B) with respect 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 photoinitiator (B) with respect 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 polymerizable compound (C) will be described.

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

[0071] The photopolymerizable compound (C) contains, for example, a compound having an ethylenically unsaturated bond. More specifically, the photopolymerizable compound (C) contains, for example, a monofunctional (meth)acrylate such as 2-hydroxyethyl (meth)acrylate; and at least one compound selected from the group consisting of 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 tangent of the cured product is more likely to be further reduced. The percentage of the compound (C1) having a tricyclodecane skeleton with respect 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] It is also preferable that the photopolymerizable compound (C) contains a trifunctional compound, that is, a compound having three unsaturated bonds in one molecule. In this case, the developability and resolution in producing a film from the photosensitive resin composition by photolithography are further improved. The trifunctional compound can contain, for example, 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] It is also preferable that the photopolymerizable compound (C) 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. The phosphorus-containing unsaturated compound can contain, for example, at least one compound selected from the group consisting of 2-methacryloyloxyethyl acid phosphate (specific examples include product numbers Light Ester P-1M and Light Ester P-2M manufactured by Kyoeisha Chemical Co., Ltd.), 2-acryloyloxyethyl acid phosphate (specific example: product number Light Acrylate P-1A manufactured by Kyoeisha Chemical Co., Ltd.), diphenyl-2-methacryloyloxyethyl phosphate (specific example: product number MR-260 manufactured by Daihachi Industry Co., Ltd.), and the HFA series manufactured by Showa Highpolymer Co., Ltd. (specific examples include product numbers HFA-6003 and HFA-6007, which are addition reaction products of dipentaerythritol hexaacrylate and HCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide), product numbers HFA-3003 and HFA-6127, which are addition reaction products of caprolactone-modified dipentaerythritol hexaacrylate and HCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide), etc.).

[0075] The photopolymerizable compound (C) may contain a prepolymer. The prepolymer can contain at least one compound selected from the group consisting of, for example, prepolymers obtained by polymerizing monomers having ethylenically unsaturated bonds and then adding ethylenically unsaturated groups, and oligo(meth)acrylate prepolymers. The oligo(meth)acrylate prepolymers can contain at least one component selected from the group consisting of, for example, 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) with respect to the carboxyl group-containing resin (A) is preferably 1% by mass or more and 50% by mass or less. This percentage is more preferably 10% by mass or more, and even more preferably 21% by mass or more. Also, this percentage is more preferably 45% by mass or less, and even more preferably 40% by mass or less.

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

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

[0079] The epoxy compound (D) preferably contains a crystalline epoxy compound (D1). In this case, the developability is more likely to be improved. Further, when the organic filler (G) described later contains an organic filler having a carboxyl group, the carboxyl groups in the organic filler facilitate the dissolution of the crystalline epoxy compound (D1) in the photosensitive resin composition. Thereby, the recrystallization of the crystalline epoxy compound (D1) can be made difficult.

[0080] The epoxy compound (D) may further contain an amorphous epoxy compound (D2). Herein, the "crystalline epoxy compound" is an epoxy compound having a melting point, and the "amorphous epoxy compound" is an epoxy compound having no melting point.

[0081] The crystalline epoxy compound (D1) preferably contains one or more components selected from the group consisting of, for example, 1,3,5-tris(2,3-epoxypropyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, a hydroquinone-type crystalline epoxy compound (specific example: product name YDC-1312 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), a biphenyl-type crystalline epoxy compound (specific example: product name YX-4000 manufactured by Mitsubishi Chemical Corporation), a diphenyl ether-type crystalline epoxy compound (specific example: product number YSLV-80DE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), a bisphenol-type crystalline epoxy compound (specific examples: product names YSLV-70XY, YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), a tetrakisphenol ethane-type crystalline epoxy compound (specific example: product number GTR-1800 manufactured by Nippon Kayaku Co., Ltd.), and a bisphenol fluorene-type crystalline epoxy compound (specific example: an epoxy resin having the structure shown in formula (2)).

[0082] The crystalline epoxy compound (D1) preferably has two epoxy groups in one molecule. In this case, it is possible to further make it difficult for cracks to occur in the cured product during 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 lower. 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 lower can contain at least one component selected from the group consisting of, for example, biphenyl-type epoxy resins (specific example: product number YX-4000 manufactured by Mitsubishi Chemical Corporation), biphenyl ether-type epoxy resins (specific example: product number YSLV-80DE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), bisphenol-type epoxy resins (specific examples: product numbers YSLV-70XY and YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical), and bisphenol fluorene-type crystalline epoxy compounds.

[0085] The amorphous epoxy compound (D2) includes, for example, phenol novolac type epoxy resins (specific example: product number EPICLON N-775 manufactured by DIC Corporation), cresol novolac type epoxy resins (specific example: product number EPICLON N-695 manufactured by DIC Corporation), bisphenol A novolac type epoxy resins (specific example: product number EPICLON N-865 manufactured by DIC Corporation), bisphenol A type epoxy resins (specific example: product number jER1001 manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins (specific example: product number jER4004P manufactured by Mitsubishi Chemical Corporation), bisphenol S type epoxy resins (specific example: product number EPICLON EXA-1514 manufactured by DIC Corporation), bisphenol AD type epoxy resins, biphenyl novolac type epoxy resins (specific example: product number NC-3000 manufactured by Nippon Kayaku Co., Ltd.), hydrogenated bisphenol A type epoxy resins (specific example: product number ST-4000D manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), naphthalene type epoxy resins (specific examples: product numbers EPICLON HP-4032, EPICLON HP-4700, EPICLON HP-4770 manufactured by DIC Corporation), tertiary butyl catechol type epoxy resins (specific example: product number EPICLON HP-820 manufactured by DIC Corporation), dicyclopentadiene type epoxy resins (specific example: product number EPICLON HP-7200 manufactured by DIC), adamantane type epoxy resins (specific example: product number ADAMANTATEX-E-201 manufactured by Idemitsu Kosan Co., Ltd.), special bifunctional type epoxy resins (specific examples: product numbers YL7175-500 and YL7175-1000 manufactured by Mitsubishi Chemical Corporation; 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 EPICLON EXA-9726 manufactured by DIC Corporation;It is preferable to contain at least one component selected from the group consisting of a rubber-like core-shell polymer-modified bisphenol A type epoxy resin (product number YSLV-120TE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), a rubber-like core-shell polymer-modified bisphenol F type epoxy resin (product number MX-156 manufactured by Kaneka Corporation as a specific example), a rubber-like core-shell polymer-modified bisphenol F type epoxy resin (product number MX-136 manufactured by Kaneka Corporation as a specific example), and a bisphenol F type epoxy resin containing rubber particles (product number Kaneka Ace MX-130 manufactured by Kaneka Corporation as a specific example).;

[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 may be contained in the amorphous epoxy compound (D2). Examples of the phosphorus-containing epoxy resin include a phosphoric acid-modified bisphenol F type epoxy resin (product numbers EPICLON EXA-9726 and EPICLON EXA-9710 manufactured by DIC Corporation), and product number Epotote FX-305 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. etc.

[0087] Regarding the amount of the epoxy compound (D) in the photosensitive resin composition, the equivalent of the epoxy group of the epoxy compound (D) is preferably 0.1 or more and less than 1 with respect to 1 equivalent of the carboxyl group of the carboxyl group-containing resin (A). In this case, while maintaining the thermosetting property of the photosensitive resin composition, the dielectric tangent of the cured product is likely to be reduced. Therefore, the cured product is likely to have more excellent dielectric properties. It is more preferable that the equivalent of this epoxy group is 0.9 or less, and even more preferable that it is 0.8 or less. Also, it is more preferable that the equivalent of this epoxy group is 0.5 or more, and even more preferable that it is 0.7 or more.

[0088] The silica (E) will be described.

[0089] As described above, when the photosensitive resin composition contains silica (E) and the percentage of silica (E) is 50% by mass or more with respect to the carboxyl group-containing resin (A), the dielectric tangent of the cured product is likely to be reduced. Further, silica (E) can reduce the coefficient of linear expansion of the cured product, making it less likely for the layer formed from the cured product to cause warping in the printed wiring board. Also, 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 more preferably 100% by mass or more, and even more preferably 130% by mass or more. Also, this percentage is more preferably 250% by mass or less, and even more preferably 220% by mass or less.

[0090] 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 be formed on the cured product, and thus the surface area of the cured product is likely to increase. Therefore, when a conductor is formed on the surface of the cured product by plating, the adhesion between the cured product and the conductor is likely to be high. Furthermore, light scattering by silica (E) can be reduced, enhancing the resolution. The average particle size of silica (E1) is more preferably 3 μm or less, and even more preferably 2 μm or less. Also, this average particle size is more preferably 0.2 μm or more, and even more preferably 0.4 μm or more. Note that the average particle size of silica (E1) is the cumulative 50% diameter (median diameter D50) calculated from the particle size distribution obtained by the laser diffraction / scattering method.

[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 be formed on the surface of the cured product. The average particle size of silica (E2) is more preferably 5 nm or more, still more preferably 20 nm or more, and particularly preferably 25 nm or more. Also, the average particle size of silica (E2) is more preferably 120 nm or less, still 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 the dynamic light scattering method.

[0092] Silica (E2) may contain two or more types of silica having different average particle sizes from each other. In this case, the resolution is more likely to be further enhanced, and when the surface of the cured product is treated with an oxidizing agent, fine irregularities are more likely to be formed on the surface of the cured product.

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

[0094] Silica (E2) preferably contains silica particles derived from a silica sol. In this case, the transparency of the photosensitive resin composition can be improved. Therefore, silica (E) can contribute to the improvement of resolution. Examples of the silica sol include spherical silica sol and chain-like silica sol. Specific examples of the silica sol include organosilica sols manufactured by Nissan Chemical Industries, Ltd.: 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, MEK-EC-6150P, 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] Silica (E) may contain silica (E1) and silica (E2). In this case, the mass ratio of silica (E1) to silica (E2) is, for example, from 50:1 to 2:1.

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

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

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

[0099] The silane coupling agent preferably has a phenyl skeleton. In this case, the particles of silica (E) are less likely to fall off. Further, 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 bisphenol fluorene skeleton, the particles of silica (E) are particularly less likely to fall off.

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

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

[0102] As described above, the blocked isocyanate compound (F) can lower the dielectric loss tangent of the cured product, can increase the flexibility of the cured product, and further can make the cured product less likely to be excessively corroded when the surface of the cured product is treated with an oxidizing agent.

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

[0104] Also, as described above, the blocked isocyanate compound (F) can enhance the developability when forming a film from the photosensitive resin composition by photolithography.

[0105] As described above, the percentage of the blocked isocyanate compound (F) with respect to the carboxyl group-containing resin (A) is 21% by mass or more and 100% by mass or less, whereby the above-described action of the blocked isocyanate compound (F) can be obtained. That is, when this percentage is 21% by mass or more, the dielectric loss tangent of the cured product can be lowered, the flexibility of the cured product can be enhanced, the surface of the cured product treated with an oxidizing agent can be made less likely to be excessively corroded, and furthermore, the developability can be enhanced. Also, when this percentage is 100% by mass or less, the developability can be enhanced. This percentage is more preferably 24% by mass or more, and even more preferably 40% by mass or more. Also, this percentage is more preferably 90% by mass or less, and even more preferably 80% by mass or less.

[0106] The details of the blocked isocyanate compound (F) will be further described. 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, 2 or more and 6 or less. The isocyanate compound may be an aliphatic, alicyclic or aromatic polyisocyanate. The isocyanate compound is, for example, 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, p-xylene diisocyanate, methylene bis(cyclohexyl isocyanate), cyclohexane-1,3-dimethylene diisocyanate, cyclohexane-1,4-dimethylene diisocyanate, 1,5-naphthalene diisocyanate, p-phenylene diisocyanate, 3,3'-methyleneditolylene-4,4'-diisocyanate, 4,4'-diphenyl ether diisocyanate, tetrachlorophenylene diisocyanate, norbornane diisocyanate, hydrogenated 1,3-xylylene diisocyanate, hydrogenated 1,4-xylylene diisocyanate and other isocyanate compounds, and contains at least one selected from the group consisting of these multimers. In particular, it is preferable that the isocyanate compound contains at least one compound selected from the group consisting of tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and multimers thereof. Examples of the multimer include biuret form, isocyanurate form, and adduct form, and the biuret form is preferable.

[0108] Examples of the blocking agent 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-based compounds, imide-based compounds, and the like. In particular, it is preferable 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 the oxime compound include oxime and ketoxime, and specific examples include acetoxime, formaldehyde oxime, cyclohexanone oxime, methyl ethyl ketone oxime, cyclohexanone oxime, benzophenone oxime, and the like. Examples of the lactam compound include ε-caprolactam, γ-butyrolactam, and the like. Examples of the phenol compound include phenol, naphthol, cresol, xylenol, halogen-substituted phenol, and the like. Examples of the alcohol compound include methanol, ethanol, propanol, butanol, cyclohexanol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, alkyl lactate, and the like. Examples of the amine compound include, for example, primary amines and secondary amines, and aniline, diphenylamine, ethyleneimine, polyethyleneimine, and the like can be exemplified. Examples of the active methylene compound include diethyl malonate, dimethyl malonate, ethyl acetoacetate, methyl acetoacetate, and the like. Examples of the pyrazole compound include pyrazole, methyl pyrazole, dimethyl pyrazole, and the like. Examples of the mercaptan compound include alkyl mercaptan, aryl mercaptan, and the like.

[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 by imparting stronger thixotropy to the photosensitive resin composition), the storage stability of the photosensitive resin composition can be further improved. Further, 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 still 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. Further, the adhesion between the cured product and the conductor is further improved.

[0111] It is particularly preferable that the reactive group contains a carboxyl group. In this case, the developability of the photosensitive resin composition is improved. Further, the carboxyl group of the organic filler (G) can react with the epoxy compound (D) in the photosensitive resin composition. Thereby, the organic filler (G) is likely to be uniformly dispersed inside the cured product. Further, the carboxyl group of the organic filler (G) can enhance the adhesion between the cured product and the conductor. 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 and the crystalline epoxy compound (D1) can be made less likely to crystallize. Further, when the photosensitive resin composition flows to form a coating film, the coating film is less likely to become non-uniform, so that the thickness of layers such as a solder resist layer and an interlayer insulating layer produced from the photosensitive resin composition is likely to be made uniform.

[0112] It is also preferable that the reactive group contains a hydroxyl group. Also in this case, it is easy to further enhance 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 carboxylic acid monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid. 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 are particularly likely to be high. When the acid value is 60 mgKOH / g or less, the moisture resistance reliability of the cured product is likely to be improved. The acid value of the organic filler (G) is more preferably 3 mgKOH / g or more. Also, 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 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. Further, when the surface of the cured product is treated with an oxidizing agent, the surface is more likely to be moderately roughened.

[0116] Specific examples of the rubber particles include product number XER-91-MEK manufactured by JSR Corporation, product number XER-32-MEK manufactured by JSR Corporation, product number XSK-500 manufactured by JSR Corporation, etc. XER-91-MEK is a crosslinked rubber (NBR) having carboxyl groups with an average primary particle diameter of 0.07 μm, and is provided as a methyl ethyl ketone dispersion with a content ratio of this crosslinked rubber of 15% by weight, and its acid value is 10.0 mgKOH / g. XER-32-MEK is a dispersion in which a polymer (linear particles) of a carboxyl group-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. Further, XSK-500 is a crosslinked rubber (SBR) having carboxyl groups and hydroxyl groups with an average primary particle diameter of 0.07 μm, and is provided as a methyl ethyl ketone dispersion with a content ratio of this crosslinked rubber of 15% by weight. Thus, the organic filler (G) may be blended into the photosensitive resin composition in the form of a dispersion. That is, the rubber particles can be blended into the photosensitive resin composition in the form of a dispersion. Further, specific examples of the organic filler (G) include, in addition to the above, product number XER-92 manufactured by JSR Corporation, etc.

[0117] The average particle diameter 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. Further, when the surface of the cured product is treated with an oxidizing agent, fine irregularities are likely to be formed on the cured product, and thereby the surface area of the cured product is likely to be increased. For this reason, the adhesion between the cured product and the conductor is more likely to be enhanced. The average particle diameter 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, and thereby the resolution is more likely to be further improved. Further, the irregularities formed by roughening the surface of the cured product are more likely to be finer. Further, the average particle diameter of the organic filler (G) is, for example, 0.001 μm or more. The average particle diameter of the organic filler (G) is the cumulative 50% diameter (median diameter %D50) calculated from the particle size distribution measured by the dynamic light scattering method.

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

[0119] The percentage of the organic filler (G) with respect 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 increase, and the stability is improved. Further, the surface of the cured product is more likely to be moderately roughened by the oxidizing agent, and the adhesion between the cured product and the conductor is more likely to be further improved. This percentage is more preferably 3% by mass or more, and even more preferably 5% by mass or more. Also, 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), it can also improve the dispersibility of the organic filler (G). Furthermore, the resolution can also be improved. The coupling agent has at least one atom selected from the group consisting of, for example, a silicon atom, an aluminum atom, a titanium atom, and a zirconium atom. Also, the coupling agent has a functional group selected from the group consisting of, for example, an alkoxy group, an acyloxy group, and an alkoxide. It is particularly preferable for the coupling agent to have a silicon atom, that is, it is preferable for the coupling agent to contain a silane coupling agent.

[0121] The percentage of the coupling agent with respect to the total of silica (E) and the organic filler (G) 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 can be made less likely to be excessively corroded. Melamine is 2,4,6-triamino-1,3,5-triazine and is generally commercially available. The average particle size of melamine is preferably 20 μm or less, and more preferably 15 μm or less. When melamine is uniformly dispersed in the photosensitive resin composition, melamine is more likely to form a coordination bond with the metal element. Thereby, the adhesiveness of the photosensitive resin composition can be further improved. The lower limit of the average particle size of melamine is not particularly limited, but it 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 the laser diffraction / scattering method in the state where melamine is dispersed in the photosensitive resin composition.

[0123] When the photosensitive resin composition contains melamine, the percentage of melamine with respect 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, still more preferably 0.5% by mass or more, and particularly preferably 1% by mass or more. Also, this percentage is more preferably 9% by mass or less, still 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 purposes such as liquefying or varnishing the photosensitive resin composition, adjusting the viscosity, adjusting the coatability, and adjusting the film-forming property.

[0125] The organic solvent can contain one or more compounds selected from the group consisting of, for example, linear, branched, secondary or polyhydric alcohols such as ethanol, propyl alcohol, isopropyl alcohol, hexanol, and ethylene glycol; 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, and carbitol acetate; 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 promptly when drying the coating film formed from the photosensitive resin composition, that is, so that the organic solvent does not remain in the dried film. In particular, with respect to the entire photosensitive resin composition, the proportion of the organic solvent 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 since the preferred proportion of the organic solvent varies depending on the coating method and the like, it is preferable that the proportion be appropriately adjusted according to the coating method.

[0127] As long as the effects of the present embodiment are not inhibited, the photosensitive resin composition may further contain components other than the above components.

[0128] The photosensitive resin composition may contain at least one resin selected from the group consisting of blocked isocyanates such as tolylene diisocyanate-based, morpholine diisocyanate-based, isophorone diisocyanate-based, and hexamethylene diisocyanate-based blocked with caprolactam, oxime, malonic ester, etc.; butylated urea resin; various thermosetting resins other than the above; ultraviolet curable epoxy (meth)acrylate; resin obtained by adding (meth)acrylic acid to an epoxy resin such as bisphenol A type, phenol novolac type, cresol novolac type, 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). Examples of the curing agent include imidazole derivatives such as imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole; amine compounds such as dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl-N,N-dimethylbenzylamine; hydrazine compounds such as adipic acid hydrazide, 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 are, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (all are trade names of imidazole-based compounds) manufactured by Shikoku Kasei Co., Ltd., U-CAT3503N, UCAT3502T (both are trade names of dimethylamine-blocked isocyanate compounds) manufactured by San-Apro Ltd., DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and their salts).

[0130] The photosensitive resin composition may contain an adhesion promoter. Examples of the adhesion promoter include 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), and 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, 2,4-diamino-6-methacryloyloxyethyl-S-triazine·isocyanuric acid adduct, silane coupling agents, melamine derivatives, and the like.

[0131] The photosensitive resin composition may contain a rheology control agent. The rheology control agent facilitates the optimization of the viscosity of the photosensitive resin composition. Examples of the rheology control agent include urea-modified medium-polar polyamides (product numbers BYK-430 and BYK-431 manufactured by Big Chemie Japan Co., Ltd.), polyhydroxycarboxylic acid amides (product number BYK-405 manufactured by Big Chemie Japan Co., Ltd.), modified urea (product numbers BYK-410, BYK-411, and BYK-420 manufactured by Big Chemie Japan Co., Ltd.), high molecular weight urea derivatives (product number BYK-415 manufactured by Big Chemie Japan Co., Ltd.), urea-modified urethanes (product number BYK-425 manufactured by Big Chemie Japan Co., Ltd.), polyurethanes (product number BYK-428 manufactured by Big Chemie Japan Co., Ltd.), 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 such as silicone and acrylate; a leveling agent; a thixotropy 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. Also, for example, 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., first knead the portion excluding the liquid components, low-viscosity components, etc. of the raw materials to prepare a mixture, and then add and mix the liquid components, low-viscosity components, etc. to the obtained mixture to prepare the photosensitive resin composition. When the photosensitive resin composition contains a solvent, first mix a part or all of the solvent among the raw materials, and then mix with the rest of the raw materials.

[0134] A printed wiring board including a cured product of the photosensitive resin composition and a method for manufacturing 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 the printed wiring board 11, for example, a photosensitive resin composition and a base material 1 are prepared. The base material 1 includes an insulating layer 2 and a second conductor layer 3 overlapping the insulating layer 2. An interlayer insulating layer 7 is formed from the photosensitive resin composition on the base material 1 by a photolithography method. That is, a film 4 made from the photosensitive resin composition is stacked on the base material 1 so as to cover the second conductor layer 3, and the negative-patterned region including the pattern of the via holes 6 in the film 4 is exposed, and then development processing is performed using an alkaline aqueous solution. Thereby, the interlayer insulating layer 7 and the via holes 6 penetrating the interlayer insulating layer 7 are formed.

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

[0139] The photosensitive resin composition is applied onto the base material 1 and further dried if necessary, thereby forming a film 4 covering the second conductor layer 3 as shown in FIG. 1B. The application method of the photosensitive resin composition is selected from the group consisting of, for example, dipping method, spraying method, spin coating method, roll coating method, curtain coating method, and 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] A film 4 may be formed by laminating a dry film containing a photosensitive resin composition on a substrate 1. The dry film is formed on a suitable support, such as a polyester support, by applying the photosensitive resin composition and then drying it. This results in a dry film with a support, comprising the dry film and the support that supports the dry film. The dry film in this dry film with a support is laminated 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. As a result, a film 4 made of the dry film is laminated on the substrate 1.

[0141] Next, the film 4 is exposed. For example, the negative pattern-shaped region of the film 4 that includes the pattern of the via hole 6 is exposed. In this case, for example, the film 4 is irradiated with ultraviolet light through a negative mask. The negative mask includes an exposure part that transmits ultraviolet light and a non-exposure part that shields ultraviolet light, and the pattern of the non-exposure part includes the pattern of the via hole 6. The negative mask is a phototool such as a mask film or a dry plate, for example. The light source of the ultraviolet light is selected from the group consisting of, for example, 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 film 4 is made from a dry film, when exposing the film 4, for example, the support is peeled off from the film 4 in advance and then the film 4 is exposed. Note that the film 4 may be exposed by irradiating the film 4 with ultraviolet light through the support while the support overlaps the film 4, and then the support may be peeled off from the exposed film 4.

[0143] As an exposure method, a method other than the method using a negative mask may be adopted. For example, the film 4 may be exposed by a direct drawing method in which ultraviolet light emitted from a light source is irradiated only on the part to be exposed on the film 4. The light source applicable to the direct drawing method is 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 combinations of two or more of g-line, h-line, and i-line.

[0144] Next, by developing the film 4 with an alkaline aqueous solution, an interlayer insulating layer 7 having via holes 6 is formed. By subjecting the film 4 to a developing process, the uncured portion 5 of the film 4 shown in FIG. 1C is removed, and thereby, as shown in FIG. 1D, via holes 6 are provided. In the developing process, an appropriate developer corresponding to the composition of the photosensitive resin composition can be used. The developer is, 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, for example, at least one component selected from the group consisting of sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate, sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, and lithium hydroxide. The solvent in the alkaline aqueous solution may be only water or a mixture of water and a hydrophilic organic solvent such as lower alcohols. The organic amine contains, for example, 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. In this case, improvement of the working environment and reduction of the burden of waste treatment can be achieved.

[0146] Since the photosensitive resin composition according to this embodiment has good developability, the residue of the uncured photosensitive resin composition is less likely to remain at the bottom of the via holes 6 after development.

[0147] Subsequently, the developed film 4 may be heat-cured by heating. The heating conditions are, for example, within a range of a heating temperature of 120°C or higher and 200°C or lower, and a heating time of 20 minutes or longer and 300 minutes or shorter. When the film 4 is heat-cured in this way, the performance such as the strength, hardness, and chemical resistance of the interlayer insulating layer 7 is improved.

[0148] If necessary, the film 4 may be further irradiated with ultraviolet rays either before or after heating, or both. In this case, the photocuring of the film 4 can be further advanced.

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

[0150] Subsequently, the first conductor layer 8 and the via conductor 9 are formed. Prior to this, 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] Subsequently, a first conductor layer 8, which is a conductor wiring, can be formed on the interlayer insulating layer 7 and a via conductor 9 can be formed in the via hole 6 by a known method such as an additive method. Thereby, as shown in FIG. 1E, a printed wiring board 11 including the first conductor layer 8, the second conductor layer 3, the interlayer insulating layer 7, the via hole 6, and the via conductor 9 is obtained. In FIG. 1E, the via conductor 9 is a film covering the inner diameter of the via hole 6, but the via conductor 9 may be filled entirely in the via hole 6.

[0152] In the present embodiment, when the surface of the interlayer insulating layer 7 is surface-treated with an oxidizing agent, the surface of the interlayer insulating layer 7 is not excessively corroded, and fine irregularities are easily formed. Therefore, the adhesion between the interlayer insulating layer 7, the first conductor layer 8, and the via conductor 9 can be enhanced.

[0153] A printed wiring board including 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, first, a core material is prepared. The core material includes, for example, at least one insulating layer and at least one conductor wiring. On the core material, a solder resist layer is formed from a photosensitive resin composition by a photolithography method. That is, a film is formed from the photosensitive resin composition on the surface of the core material where the conductor wiring is provided. Examples of the film formation method include a coating method and a dry film method. As the coating method and the dry film method, the same methods as those for forming the above-mentioned interlayer insulating layer can be adopted. The film is partially cured by exposure. The same exposure method as that for forming the above-mentioned interlayer insulating layer can also be adopted. Subsequently, the unexposed portion of the film is removed by subjecting the film to a development process, whereby the exposed portion of the film remains on the core material. Subsequently, the film on the core material is heat-cured by heating. The same development method and heating method as those for forming the above-mentioned interlayer insulating layer can also be adopted. If necessary, the film may be further irradiated with ultraviolet light either before or after heating, or both. In this case, the photocuring of the film 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 described above, a solder resist layer made of a cured product of a photosensitive resin composition is provided on the core material. Thereby, a printed wiring board including a core material having an insulating layer and a conductor wiring thereon, and a solder resist layer that partially covers the surface of the core material where the conductor wiring is provided is obtained. Note that, similar to the case of the interlayer insulating layer, the surface of the solder resist layer may be roughened by surface treatment with an oxidizing agent. Thereby, the adhesion between the solder resist layer and the conductor constituting the conductor wiring, solder, etc. can be improved.

Example

[0157] Hereinafter, specific examples of the present embodiment will be presented. However, the present embodiment is not limited to only the following examples.

[0158] 1. Synthesis of carboxyl group-containing resin (1) Synthesis Example A-1: Synthesis of resin having a bisphenol fluorene skeleton Into a four-necked flask equipped with a reflux condenser, thermometer, air blowing tube, and stirrer, 250 parts by mass of a bisphenol fluorene type epoxy compound (an epoxy compound represented by formula (2) with all of R1 to R8 in formula (2) being hydrogen and 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 under air bubbling. The mixture was heated at 115°C for 12 hours while stirring under air bubbling in the flask. Thereby, a solution of the intermediate was prepared. Subsequently, 60.8 parts by mass of 1,2,3,6-tetrahydrophthalic anhydride, 58.8 parts by mass of 3,3’,4,4’-biphenyltetracarboxylic dianhydride, and 38.7 parts by mass of propylene glycol monomethyl ether acetate were added to the solution of the intermediate in the flask. These were heated at 115°C for 6 hours while stirring under air bubbling, and further heated at 80°C for 1 hour while stirring under air bubbling. Thereby, a solution of carboxyl group-containing resin A-1 (solid content 65% by mass) was obtained. The polydispersity (Mw / Mn) of 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 a biphenyl novolak skeleton Into a four-necked flask equipped with a reflux condenser, thermometer, air inlet tube, and stirrer, 288 parts by mass of a biphenyl novolak type 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 were added to prepare a mixture. This mixture was heated in the flask at a temperature of 115 °C for 12 hours while stirring under air bubbling. Thereby, a solution of the intermediate was prepared.

[0160] Subsequently, 91.2 parts by mass of tetrahydrophthalic anhydride and 90 parts by mass of diethylene glycol monoethyl ether acetate were added to the solution of the intermediate in the flask, and the mixture was heated at 90 °C for 4 hours while stirring under air bubbling. Thereby, a solution of carboxyl group-containing resin A-2 (solid content 65% by mass) was obtained. 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 powdery raw materials and the carboxyl group-containing resin were kneaded in advance using a three-roll mill, and then the remaining raw materials were blended and stirred and mixed in the flask at 35 °C to obtain a photosensitive resin composition.

[0162] "Raw material (solid content) / parts by mass" in the table indicates the blending amount of the raw materials. When the raw material contains a solvent, the blending amount of the raw material is the amount of the solid content excluding the solvent in the raw material. The details of the raw materials are as follows. Also, "E / A" in the table indicates the equivalent of the epoxy group of the epoxy compound with respect to 1 equivalent of the carboxyl group of the carboxyl group-containing resin in the raw material. - Photoinitiator A: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, manufactured by BASF, product number Irgacure TPO. - Photoinitiator B: 1-hydroxy-cyclohexyl-phenyl-ketone, manufactured by BASF, product number Irgacure 184. - Photoinitiator C: 4,4'-bis(diethylamino)benzophenone. - Photoinitiator 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 187 g / eq. - Epoxy compound B: bisphenol-type crystalline epoxy resin, product number YSLV-80XY manufactured by Nippon Steel Chemical & Material Co., Ltd., melting point 75 - 85 °C, epoxy equivalent 192 g / eq. - Block isocyanate compound A: product number Duranate MF-B60B manufactured by Asahi Kasei Corporation. A solution of hexamethylene diisocyanate type methyl ethyl ketone oxime blocked isocyanate compound in n-butyl acetate n-butanol. Solids content 60 mass%. Curing temperature 120 °C or higher. - Block isocyanate compound B: product number Duranate SBB-70P manufactured by Asahi Kasei Corporation. A solution of a blocked isocyanate compound having a biuret structure as the parent structure and a 1,3-dimethylpyrazole skeleton as the blocked structure in propylene glycol monomethyl ether acetate. Solids content 70 mass%. Curing temperature 110 °C or higher. - Block isocyanate compound C: product number Duranate SBN-70D manufactured by Asahi Kasei Corporation. A solution of a pyrazole derivative blocked isocyanate of 1,6-hexamethylene diisocyanate in dipropylene glycol monomethyl ether. Solids content 70 mass%. Curing temperature 110 °C or higher. - Block isocyanate compound D: product number Duranate 17B-60P manufactured by Asahi Kasei Corporation. A solution of a blocked isocyanate compound having a biuret structure as the parent structure and an oxime ester structure as the blocked structure in propylene glycol monomethyl ether acetate. Solids content 60 mass%. Curing temperature 130 °C or higher. - Isocyanate compound: Product number Duranate TPA-100 manufactured by Asahi Kasei Corporation. An isocyanate prepolymer having 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. A slurry containing silica with an average particle size of 0.5 μm treated with phenylsilane and methyl ethyl ketone. Solid content 70% by mass. - Dispersion of silica B: Product number SC2050-MTX manufactured by Admatechs Co., Ltd. A 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. A slurry containing silica with an average particle size of 0.5 μm treated with vinylsilane and methyl ethyl ketone. Solid content 70% by mass. - Dispersion of silica D: Product number SC2050-MB manufactured by Admatechs Co., Ltd. A slurry containing silica with an average particle size of 0.5 μm treated with epoxysilane and methyl ethyl ketone. Solid content 70% by mass. - Dispersion of silica E: Product number 5SQ-CM2 manufactured by Admatechs Co., Ltd. A slurry containing silica with an average particle size of 0.5 μm without surface treatment and methyl ethyl ketone. Solid content 70% by mass. - Solvent dispersion of silica sol A: Product number MEK-EC-2130Y manufactured by Nissan Chemical Industries, Ltd. A dispersion 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 Industries, Ltd. A dispersion 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: Product number XER-91-MEK manufactured by JSR Corporation. A dispersion containing crosslinked 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: Product number OPE-2St 1200 manufactured by Mitsubishi Gas Chemical Company, Inc. A dispersion containing a vinylbenzyl-modified polyphenylene ether oligomer with a number average molecular weight of 1187 and a vinyl group equivalent of 590 g / eq, and toluene. Solids content: 65% by mass. - Antioxidant: Product number 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: Product number Megafac F-477 manufactured by DIC Corporation. - Solvent: Methyl ethyl ketone.

[0163] 3. Preparation of test pieces (1) Preparation of test piece 1 Test pieces for conducting the tests (1) to (8) in the following "4. Evaluation tests" were prepared as follows.

[0164] A photosensitive resin composition was applied onto a polyethylene terephthalate film with an applicator and then dried by heating at 90 °C for 30 minutes, thereby forming a dry film with a thickness of 30 μm on the film. A glass epoxy copper-clad laminate (FR-4 type) having a copper foil with a thickness of 17.5 μm was prepared. A comb-shaped electrode with a line width / space width of 30 μm / 30 μm was formed as a conductor wiring on this glass epoxy copper-clad laminate by a subtractive method, thereby obtaining a core material. The surface portion of about 1 μm in thickness in the conductor wiring of this core material was removed by dissolution with an etching agent (product number CZ-8101 manufactured by Meck Co., Ltd.), thereby roughening the conductor wiring. This core material was heat-laminated with a dry film using a vacuum laminator so that the film was overlapped and covered the conductor wiring. The conditions for heat lamination were 0.5 MPa, 80 °C, and 1 minute. Thereby, a film made of the above dry film was formed on the core material. Next, at the time of exposing the film, while directly applying a negative mask having a non-exposed portion having a pattern including circular shapes with diameters of 100 μm, 80 μm, and 60 μm to the film overlapping the film, ultraviolet rays were irradiated through the film under the conditions of 300 mJ / cm 2 . After peeling the film from the dry film (film) after exposure, the film was developed. At the time of development, a 1% Na2CO3 aqueous solution at 30 °C was sprayed onto the film at an injection pressure of 0.2 MPa for 90 seconds. Subsequently, pure water was sprayed onto the film at an injection pressure of 0.2 MPa for 90 seconds. Thereby, the unexposed portion in the film was removed, and via holes were formed in the film. Subsequently, the film was heated at 180 °C for 120 minutes. Thereby, 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) was formed on the core material. Thereby, a test piece was obtained.

[0165] (2) Preparation of test piece 2 Test pieces for performing the tests (9) and (10) in the following “4. Evaluation test” were prepared as follows.

[0166] The photosensitive resin composition was applied onto a polyethylene terephthalate film using an applicator, and then dried by heating at 90 °C for 30 minutes, thereby forming a dry film with a thickness of 50 μm on the film. While the dry film remained overlapping with the film, it was heat-laminated onto the entire surface of one side of a Teflon (registered trademark) film using a vacuum laminator. The conditions for heat-lamination were 0.5 MPa, 80 °C, and 1 minute. As a result, a film with a thickness of 50 μm and composed of the dry film was formed on the Teflon film. Next, when exposing the film, with a mask having a rectangular exposure area of 3 mm × 85 mm directly applied onto the film overlapping the film, ultraviolet rays were irradiated through the mask onto the film with a condition of 300 mJ / cm 2 After exposure, the film was peeled off from the dry film (film). Subsequently, when developing the film, a 1% Na2CO3 aqueous solution at 30 °C was injected onto the film at an injection pressure of 0.2 MPa for 90 seconds. Subsequently, the film was washed by injecting pure water onto the film at an injection pressure of 0.2 MPa for 90 seconds. Subsequently, the film was heated at 180 °C for 120 minutes. As a result, a cured product of the photosensitive resin composition (cured product of the dry film) was formed 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 During the process of preparing the test piece, the unexposed portion of the film after development was observed, and the results were evaluated as follows. A: All unexposed portions of the film were removed. B: A part of the unexposed portion of the film remained on the core material. When additional development for 30 seconds (1% Na2CO3 aqueous solution, 0.2 MPa) was performed, all unexposed portions were removed. C: A part of the unexposed portion of the film remained on the core material. Even when additional development for 30 seconds (1% Na2CO3 aqueous solution, 0.2 MPa) was performed, a part of the unexposed portion remained on the core material. D: Development was not possible.

[0168] In the case where the evaluation was "D", the tests after (2) below were not performed.

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

[0170] The holes corresponding to the patterns of 100 μm, 80 μm, and 60 μm in diameter in the mask at the time of producing the cured product in the cured product of the test piece after the above treatment were observed, and the results were evaluated as follows. A: The holes corresponding to the pattern of 100 μm in diameter, the holes corresponding to the pattern of 80 μm in diameter, and the holes corresponding to the pattern of 60 μm in diameter were all open. B: The holes corresponding to the pattern of 100 μm in diameter and the holes corresponding to the pattern of 80 μm in diameter were open, but the holes corresponding to the pattern of 60 μm in diameter were not open. C: The holes corresponding to the pattern of 100 μm in diameter were open, but the holes corresponding to the pattern of 80 μm in diameter and the holes corresponding to the pattern of 60 μm in diameter were not open. D: The holes corresponding to the pattern of 100 μm in diameter, the holes corresponding to the pattern of 80 μm in diameter, and the holes corresponding to the pattern of 60 μm in diameter were all not open.

[0171] (3) Plating resistance When preparing the test piece, a part of the conductor wiring was not covered with a layer made of a cured product. On a part of the conductor wiring in this test piece, a nickel plating layer was formed using a commercially available electroless nickel plating bath, and then a gold plating layer was formed using a commercially available electroless gold plating bath. As a result, a metal layer composed of a nickel plating layer and a gold plating layer was formed. The layer made of a cured product and the metal layer were visually observed. In addition, a cellophane adhesive tape peeling test was performed on the layer made of a cured product. The results were evaluated as follows. A: No abnormality was observed in the appearance of the layer made of a cured product and the metal layer, and peeling of the layer made of a cured product did not occur in the cellophane adhesive tape peeling test. B: Discoloration was observed in the layer made of a cured product, but peeling of the layer made of a cured product did not occur in the cellophane adhesive tape peeling test. C: Significant discoloration was observed in the layer made of a cured product, but peeling of the layer made of a cured product did not occur in the cellophane adhesive tape peeling test. D: Lifting of the layer made of a cured product was observed, and peeling of the layer made of a cured product occurred in the cellophane adhesive tape peeling test.

[0172] (4) Insulation While applying a bias voltage of DC 5V to the conductor wiring (comb-shaped electrode) in the test piece, the printed wiring board was exposed to a test environment of 130°C and 85% R.H. for 200 hours. The electrical resistance value between the comb-shaped electrodes of the layer made of a cured product in this test environment was constantly measured, and the results were evaluated according to the following evaluation criteria. A: The electrical resistance value always maintained 10 6 Ω or more from the start of the test until 200 hours elapsed. B: The electrical resistance value always maintained 10 6 Ω or more until 150 hours elapsed from the start of the test, but the electrical resistance value became less than 10 6 Ω before 200 hours elapsed from the start of the test. C: The electrical resistance value always maintained 10 6 Ω or more until 100 hours elapsed from the start of the test, but the electrical resistance value became less than 10 6It became less than D: Before 100 hours had elapsed since the start of the test, the electrical resistance value became 10 6 Ω or less.

[0173] (5) PCT (Pressure Cooker Test) After leaving the test piece in an environment of 121°C and 100% RH for 100 hours, the appearance of the layer made of the cured product was evaluated according to the following evaluation criteria. A: No abnormality was observed in the layer made of the cured product. 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 product, and swelling occurred in some parts.

[0174] (6) Thermal Shock Resistance Water-soluble flux (manufactured by London Chemical Co., Ltd., product number LONCO 3355-11) was applied to the layer made of the cured product of the test piece. Subsequently, the test piece was immersed in a molten solder bath at 280°C for 30 seconds and then in water at 25°C for 30 seconds. After that, the appearance of the layer made of the cured product was observed. This process was repeated 5 times, and the thermal shock resistance was evaluated as follows. A: Even after 5 treatments, no abnormalities such as swelling, peeling, and cracking were observed in the layer made of the cured product. B: After 5 treatments, abnormalities such as swelling, peeling, and cracking were observed in the layer made of the cured product, but after 4 treatments, no abnormalities such as swelling, peeling, and cracking were observed in the layer made of the cured product. C: After 4 treatments, abnormalities such as swelling, peeling, and cracking were observed in the layer made of the cured product, but after 3 treatments, no abnormalities such as swelling, peeling, and cracking were observed in the layer made of the cured product. D: Within 3 treatments, abnormalities such as swelling, peeling, and cracking were observed in the layer made of the cured product.

[0175] (7) Resistance to Roughening (Evaluation of the Thickness of the Cured Product Layer after Roughening) The layer made of the cured product in the test piece was treated with a swelling treatment liquid, an oxidizing agent, and a neutralizing agent in the same manner as in the method described in the above "(2) Openability" to roughen the surface of this layer.

[0176] The surface of the layer made of this cured product was observed. Subsequently, after subjecting the layer made of the cured product to ultrasonic cleaning (42 kHz, 30 seconds), it was observed again.

[0177] Based on the results, the resistance of the cured product to the oxidizing agent was evaluated according to the following evaluation criteria. A: No whitening phenomenon was observed on the surface of the layer made of the cured product, and no significant change was seen in the surface uneven shape even after ultrasonic cleaning. B: No whitening phenomenon was observed on the surface of the layer made of the cured product, but a slight desorption of silica from the surface was confirmed after ultrasonic cleaning. C: A slight whitening phenomenon was observed on the surface of the layer made of the cured product, and desorption of silica from the surface was confirmed after ultrasonic cleaning. D: The surface of the layer made of the cured product was strongly whitened, and desorption of silica from the surface was confirmed after ultrasonic cleaning.

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

[0179] Subsequently, after producing an initial wiring by electroless copper plating treatment using a commercially available chemical solution on the layer made of the cured product, the test piece was heated at 150 °C for 1 hour. Next, by electrolytic copper plating treatment under the condition of a current density of 2 A / dm 2 copper with a thickness of 33 μm was deposited on the initial wiring to produce a copper plating layer. Subsequently, the test piece was heated at 180 °C for 30 minutes.

[0180] In 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 and 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 and 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 dielectric constant 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 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 (tan δ) of the test piece was measured at a frequency of 10 GHz using a dielectric constant measuring device (manufactured by AET Corporation, ADMS01O) in accordance with JIS C2565 by the cavity resonator method. The results were evaluated as follows. A: The dielectric tangent is less than 0.008. B: The dielectric 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 loss tangent is 0.012 or more.

[0183]

Table 1

[0184]

Table 2

[0185]

Table 3

Claims

1. A carboxyl group-containing resin (A), a photoinitiator (B), a photopolymerizable compound (C), an epoxy compound (D), silica (E) having a percentage of 50% by mass or more and 300% by mass or less with respect to the carboxyl group-containing resin (A) and surface-treated with a silane coupling agent, and a blocked isocyanate compound (F) having a percentage of 21% by mass or more and 100% by mass or less with respect to the carboxyl group-containing resin (A), wherein the silane coupling agent has a phenyl skeleton, a photosensitive resin composition.

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

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

4. The photoinitiator (B) contains an acylphosphine oxide-based photoinitiator (B1), The photosensitive resin composition according to any one of Claims 1 to 3.

5. The equivalent of the epoxy group of the epoxy compound (D) is 0.1 or more and less than 1 with respect to 1 equivalent of the carboxyl group of the carboxyl group-containing resin (A), The photosensitive resin composition according to any one of Claims 1 to 4.

6. The epoxy compound (D) contains a crystalline epoxy compound (D1), The photosensitive resin composition according to any one of Claims 1 to 5.

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 multimers thereof, The photosensitive resin composition according to any one of Claims 1 to 6.

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 diameter of 0.1 μm or more and 5 μm or less, The photosensitive resin composition according to any one of claims 1 to 8.

10. Further comprising an organic filler (G) containing at least one kind 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 any one of claims 1 to 9.

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

12. Containing the photosensitive resin composition according to any one of claims 1 to 11 Dry film.

13. Obtained by curing the photosensitive resin composition according to any one of claims 1 to 11 Cured product.

14. Comprising an interlayer insulating layer containing the cured product according to claim 13 Printed wiring board.

15. Comprising a solder resist layer containing the cured product according to claim 13 Printed wiring board.

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