TWI722308B - Manufacturing method of multi-layered printed wiring board and multi-layered printed wiring board - Google Patents

Abstract

The present invention provides a method for manufacturing a multilayer printed wiring board, which can achieve high adhesion between the interlayer insulating layer and the conductor layer even if the interlayer insulating layer is not roughened or the degree of roughening is small. The manufacturing method of a multilayer printed wiring board (20) is to make a film (4) from a photosensitive resin composition on a printed wiring board (1), and then photo-curing it to produce a cured film (11), and then The cured film (11) is first treated with an alkaline solution, and then the conductor layer (8) is formed. The photosensitive resin composition contains a carboxyl group-containing resin (A), an unsaturated compound (B) having at least one ethylenically unsaturated bond in one molecule, a photopolymerization initiator (C), and an epoxy compound (D). Immediately before the production of the conductor layer (8), the arithmetic average roughness Ra of the surface of the cured film (11) that is in contact with the conductor layer (8) is less than 150 nm.

Description

Manufacturing method of multilayer printed circuit board and multilayer printed circuit board

The invention relates to a manufacturing method of a multilayer printed circuit board and a multilayer printed circuit board.

Conventionally, in order to produce electrical insulating layers such as a solder resist layer, a plating resist layer, an etching resist layer, and an interlayer insulating layer of a printed wiring board, an electrically insulating resin composition has been used. Such a resin composition is, for example, a photosensitive resin composition (see Patent Document 1).

Especially when the interlayer insulating layer is made of a photosensitive resin composition, the interlayer insulating layer is roughened in order to ensure the adhesion between the interlayer insulating layer and the conductive layer formed thereon by plating or the like. (Refer to Patent Document 1). If the interlayer insulating layer is roughened, the high-frequency characteristics of the printed wiring board will deteriorate, and therefore the high-speed signal transmission characteristics of the printed wiring board will deteriorate. [Prior Art Document] (Patent Document)

Patent Document 1: Japanese Patent Application Laid-Open No. 11-242330

The object of the present invention is to provide a method for manufacturing a multilayer printed wiring board and a multilayer printed wiring board, which can achieve a bond between the interlayer insulating layer and the conductor layer even if the interlayer insulating layer is not roughened or the degree of roughening is small. High tightness.

One aspect of the method for manufacturing a multilayer printed wiring board of the present invention is to produce a film from the photosensitive resin composition on the printed wiring board. The aforementioned photosensitive resin composition contains: a carboxyl group-containing resin (A), an unsaturated compound (B) having at least one ethylenically unsaturated bond in one molecule, a photopolymerization initiator (C), and an epoxy compound (D) . By photocuring the aforementioned film, a cured film is produced. The cured film is first treated with an alkaline solution, and then a conductor layer in contact with the cured film is formed. Immediately before the formation of the conductor layer, the arithmetic average roughness Ra specified by Japanese Industrial Standards (JIS) B0601-2001 of the surface of the cured film that is in contact with the conductor layer is less than 150 nm.

One aspect of the multilayer printed circuit board of the present invention is manufactured by the aforementioned manufacturing method.

The following embodiment relates to a manufacturing method of a multilayer printed circuit board and a multilayer printed circuit board manufactured by this manufacturing method, and in particular to a manufacturing method of a multilayer printed circuit board and a manufacturing method manufactured by this manufacturing method A multilayer printed wiring board in which this manufacturing method produces a cured film of the photosensitive resin composition on the printed wiring board.

Hereinafter, one embodiment of the present invention will be described. In addition, in the following description, "(meth)acrylic acid" means at least one of "acrylic acid" and "methacrylic acid". For example, (meth)acrylate means at least one of acrylate and methacrylate.

The manufacturing method of the multilayer printed wiring board 20 of this embodiment (refer to FIG. 1A to FIG. 1E) is to produce the film 4 on the printed wiring board 1 from the photosensitive resin composition. The photosensitive resin composition contains a carboxyl group-containing resin (A), an unsaturated compound (B) having at least one ethylenically unsaturated bond in one molecule, a photopolymerization initiator (C), and an epoxy compound (D). By photocuring this film 4, a cured film 11 is produced. This cured film 11 is first treated with an alkaline solution, and then the conductor layer 8 in contact with the cured film 11 is formed. Immediately before the conductor layer 8 is produced, the arithmetic average roughness Ra specified by JIS B0601-2001 of the surface of the cured film 11 that is in contact with the conductor layer 8 is less than 150 nm.

In this embodiment, the arithmetic average roughness Ra of the cured film 11 is less than 150 nm. Therefore, even if the conductor layer 8 in contact with the cured film 11 is produced, the deterioration of the high-frequency characteristics of the multilayer printed wiring board 20 can be suppressed, and thus it can be maintained well High-speed signal transmission characteristics of the multilayer printed circuit board 20.

Furthermore, by processing the cured film 11 with an alkaline solution, the adhesion between the interlayer insulating layer 7 and the conductor layer 8 made of the cured film 11 can be improved. Although the reason is not fully understood, it is thought that if the cured film 11 is treated with an alkaline solution, the surface of the cured film 11 will not be greatly roughened, but fine irregularities will occur. It is presumed that this is interlayer insulation. One of the reasons why the adhesion between the layer 7 and the conductor layer 8 is improved.

Therefore, even if the interlayer insulating layer 7 is not roughened or the degree of roughening is small, high adhesion between the interlayer insulating layer 7 and the conductor layer 8 can be achieved.

The photosensitive resin composition used in this embodiment is demonstrated in detail.

As described above, the photosensitive resin composition contains: a carboxyl group-containing resin (A), an unsaturated compound (B) having at least one ethylenically unsaturated bond in one molecule, a photopolymerization initiator (C), and an epoxy compound (D).

The carboxyl group-containing resin (A) preferably contains a carboxyl group-containing resin having an ethylenically unsaturated group. In this case, the carboxyl group-containing resin (A) can have photoreactivity. Therefore, the carboxyl group-containing resin (A) can impart photosensitivity to the photosensitive resin composition, specifically, can impart violet line curability to the photosensitive resin composition.

The carboxyl group-containing resin (A) preferably contains a carboxyl group-containing resin having an aromatic ring. In this case, it is possible to impart high heat resistance and insulation reliability to the cured product of the photosensitive resin composition.

The carboxyl group-containing resin (A) more preferably contains a carboxyl group-containing resin having any one of a biphenyl skeleton, a naphthalene skeleton, a sulphur skeleton, and an anthracene skeleton. In this case, it is possible to impart higher heat resistance and insulation reliability to the cured product of the photosensitive resin composition.

The carboxyl group-containing resin (A) preferably contains a carboxyl group-containing resin (A1) having a bisphenol sulfonate skeleton. In this case, it is possible to impart further higher heat resistance and insulation reliability to the cured product of the photosensitive resin composition containing the carboxyl group-containing resin (A).

The carboxyl group-containing resin (A1) is, for example, the reaction product of an intermediate with acid dianhydride (a3) and acid monoanhydride (a4). The intermediate is a combination of epoxy compound (a1) and unsaturated group-containing carboxylic acid (a2) Reactant. The epoxy compound (a1) has a bisphenol sulfide skeleton. The bisphenol sulfonate skeleton is represented by the following formula (1). In the formula (1), R ₁ to R ₈ are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen.

式(1)中的各個R₁ ～R₈ 可以是氫，亦可以是碳數1～5的烷基或鹵素。原因在於，即便芳香環中的氫被低分子量的烷基或鹵素取代，也不會對含羧基樹脂(A1)的物性有不良影響，反而有時也會提升包含了含羧基樹脂(A1)之感光性樹脂組成物的硬化物的耐熱性或難燃性。

_{Each of R 1} to R ₈ in the formula (1) may be hydrogen, or may be an alkyl group having 1 to 5 carbon atoms or halogen. The reason is that even if the hydrogen in the aromatic ring is substituted by a low-molecular-weight alkyl or halogen, it will not adversely affect the physical properties of the carboxyl-containing resin (A1). On the contrary, it may increase the carboxyl-containing resin (A1). The heat resistance or flame retardancy of the cured product of the photosensitive resin composition.

If the carboxyl group-containing resin (A1) has a bisphenol skeleton derived from the epoxy compound (a1), it is possible to impart high heat resistance and insulation reliability to the cured product of the photosensitive resin composition containing the carboxyl group-containing resin (A1).

The carboxyl group-containing resin (A1) will be explained more specifically. In order to synthesize the carboxyl group-containing resin (A1), first, at least a part of the epoxy groups in the epoxy compound (a1) having the bisphenol sulfide skeleton represented by the formula (1) are combined with the unsaturated group-containing carboxylic acid The carboxylic acid (a2) of (a2-1) reacts to synthesize an intermediate. The synthesis of intermediates is defined as the first reaction. The intermediate has a secondary hydroxyl group, which is produced by the ring-opening addition reaction of an epoxy group and a carboxylic acid (a2) containing an unsaturated group-containing carboxylic acid (a2-1). Then, the secondary hydroxyl group in the intermediate is reacted with the acid anhydride (a3). Thereby, the carboxyl group-containing resin (A1) can be synthesized. The reaction of the intermediate and acid anhydride (a3) is defined as the second reaction. The acid anhydride (a3) can include acid monoanhydrides and acid dianhydrides. Acid monoanhydride refers to a compound with one acid anhydride group, which is formed by dehydration and condensation of two carboxyl groups in one molecule. Acid dianhydride refers to a compound with 2 acid anhydride groups, which is formed by dehydration and condensation of 4 carboxyl groups in one molecule.

The carboxyl group-containing resin (A1) may contain unreacted components in the intermediate. In addition, when the acid anhydride (a3) contains an acid monoanhydride and an acid dianhydride, the carboxyl group-containing resin (A1), in addition to the reactant containing the components in the intermediate, the components in the acid mono anhydride, and the components in the acid dianhydride, It may also contain any one or both of the reactant of the component in the intermediate and the component in the acid monoanhydride, and the reactant of the component in the intermediate and the component in the acid dianhydride. That is, the carboxyl group-containing resin (A1) may be a mixture of plural kinds of compounds having different structures like this.

The carboxyl group-containing resin (A1) has photoreactivity by having an ethylenically unsaturated group derived from the unsaturated group-containing carboxylic acid (a2-1). Therefore, the carboxyl group-containing resin (A1) can impart photosensitivity to the photosensitive resin composition, specifically, can impart ultraviolet curability to the photosensitive resin composition. Furthermore, the carboxyl group-containing resin (A1), by having a carboxyl group derived from the acid anhydride (a3), can impart developability to the photosensitive resin composition by an alkaline aqueous solution containing an alkali metal salt and an alkali metal hydrogen. At least one of oxides.

The weight average molecular weight of the carboxyl group-containing resin (A1) is preferably in the range of 700 or more and 10,000 or less. If the weight average molecular weight is 700 or more, the insulation of the cured product of the photosensitive resin composition can be improved, and the dielectric loss tangent can be reduced. In addition, if the weight average molecular weight is 10,000 or less, the developability of the photosensitive resin composition with an alkaline aqueous solution can be particularly improved. The weight average molecular weight is more preferably 900 or more, and particularly preferably 1,000 or more. In addition, the weight average molecular weight is more preferably in the range of 8,000 or less, and particularly preferably in the range of 5,000 or less.

Preferably, the polydispersity of the carboxyl group-containing resin (A1) is in the range of 1.0 or more and 4.8 or less. In this case, it is possible to ensure good insulation properties of the cured product formed of the photosensitive resin composition, and to impart excellent developability to the photosensitive resin composition. More preferably, the polydispersity of the carboxyl group-containing resin (A1) is 1.1 or more and 4.0 or less, and still more preferably 1.2 or more and 2.8 or less.

The number average molecular weight and molecular weight distribution of the carboxyl-containing resin (A1) as described above can be achieved by making the carboxyl-containing resin (A1) a mixture containing the following components appropriately: unreacted components in the intermediate; intermediate The reactant of the components in the body, the components in the acid monoanhydride and the components in the acid dianhydride; the reactant of the components in the intermediate and the components in the acid monoanhydride; the components in the intermediate and the components in the acid dianhydride The reactant. More specifically, it can be achieved by controlling, for example, the following parameters: the average molecular weight of the epoxy compound (a1), the amount of acid monoanhydride relative to the epoxy compound (a1), and the acid dianhydride relative to the epoxy compound (a1) ) Amount.

In addition, the polydispersity is the ratio (Mw/Mn) of the weight average molecular weight (Mw) of the carboxyl group-containing resin (A1) to the number average molecular weight (Mn).

The solid acid value of the carboxyl group-containing resin (A1) is preferably in the range of 60 mgKOH/g or more and 140 mgKOH/g or less. In this case, the developability of the photosensitive resin composition can be particularly improved. It is more preferable if the acid value is in the range of 80 mgKOH/g or more and 135 mgKOH/g or less; and it is even more preferable if the acid value is in the range of 90 mgKOH/g or more and 130 mgKOH/g or less.

The molecular weight of the carboxyl group-containing resin (A1) can be adjusted by crosslinking with acid dianhydride. At this time, a carboxyl group-containing resin (A1) whose acid value and molecular weight have been adjusted can be obtained. That is, by controlling the amount of the acid dianhydride contained in the acid anhydride (a3), the molecular weight and acid value of the carboxyl group-containing resin (A1) can be easily adjusted. In addition, the molecular weight of the carboxyl group-containing resin (A1) is calculated based on the measurement result obtained by Gel Permeation Chromatography (GPC) under the following conditions. GPC device: manufactured by Showa Denko Corporation, trade name: SHODEX SYSTEM 11; Column: SHODEX KF-800P, KF-005, KF-003, KF-001, 4 tubes in series; Mobile phase: Tetrahydrofuran (THF); Flow rate: 1ml /Min; column temperature: 45℃; detector: refractive index (RI) detector; conversion: polystyrene.

The raw materials of the carboxyl group-containing resin (A1) and the reaction conditions when synthesizing the carboxyl group-containing resin (A1) are explained in detail.

The epoxy compound (a1) has a structure represented by the following formula (2), for example. N in formula (2) is an integer in the range of 0-20, for example. In order to appropriately control the molecular weight of the carboxyl group-containing resin (A1), the average of n is particularly preferably in the range of 0 to 1. If the average of n is in the range of 0 to 1, even when the acid anhydride (a3) contains an acid dianhydride, it becomes easy to suppress an excessive increase in molecular weight.

The carboxylic acid (a2) includes the unsaturated group-containing carboxylic acid (a2-1). The carboxylic acid (a2) may include only the unsaturated group-containing carboxylic acid (a2-1). Alternatively, the carboxylic acid (a2) may include carboxylic acids other than the unsaturated group-containing carboxylic acid (a2-1) and the unsaturated group-containing carboxylic acid (a2-1).

The unsaturated group-containing carboxylic acid (a2-1) may contain, for example, a compound having only one ethylenically unsaturated group. More specifically, the unsaturated group-containing carboxylic acid (a2-1) can contain, for example, one or more compounds selected from the group consisting of acrylic acid, methacrylic acid, and ω-carboxy-polycaprolactone (n≒2) Monoacrylate, crotonic acid, cinnamic acid, succinic acid mono(2-propenyloxyethyl) ester, succinic acid mono(2-methacryloyloxyethyl) ester, phthalic acid Mono(2-propenyloxyethyl) formate, mono(2-methacryloyloxyethyl) phthalate, mono(2-propenyloxypropyl) phthalate, Mono(2-methacryloxypropyl) phthalate, mono(2-methacryloxyethyl) maleate, mono(2-methacryloxyethyl) maleate ) Ester, β-carboxyethyl acrylate, tetrahydrophthalic acid mono(2-propenyloxyethyl) ester, tetrahydrophthalic acid mono(2-methacryloyloxyethyl) ester, Hexahydrophthalic acid mono(2-propenyloxyethyl) ester, and hexahydrophthalic acid mono(2-methacryloyloxyethyl) ester. Preferably, the unsaturated group-containing carboxylic acid (a2-1) contains acrylic acid.

The carboxylic acid (a2) may include a polybasic acid (a2-2). Polyacid (a2-2) is an acid in which two or more hydrogen atoms in a molecule can be substituted with metal atoms. The polybasic acid (a2-2) preferably has two or more carboxyl groups. At this time, the epoxy compound (a1) can react with both the unsaturated group-containing carboxylic acid (a2-1) and the polybasic acid (a2-2). By cross-linking the epoxy group and the polybasic acid (a2-1) existing in two molecules of the epoxy compound (a1), the molecular weight can be increased. Thereby, the insulation of the cured product of the photosensitive resin composition can be improved, and the dielectric loss tangent can be reduced.

The polybasic acid (a2-2) preferably contains a dicarboxylic acid. The polybasic acid (a2-2) can contain, for example, one or more compounds selected from the group consisting of 4-cyclohexene-1,2-dicarboxylic acid, oxalic acid, malonic acid, succinic acid, and glutaric acid. Diacid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid. Preferably, the polybasic acid (a2-2) contains 4-cyclohexene-1,2-dicarboxylic acid.

When the epoxy compound (a1) and the carboxylic acid (a2) are reacted, a known method can be adopted. For example, a carboxylic acid (a2) is added to a solvent solution of the epoxy compound (a1), a thermal polymerization inhibitor and a catalyst are further added as necessary, and they are stirred and mixed to obtain a reactive solution. The intermediate can be obtained by the following method: According to a conventional method, it is more preferred to react the reactive solution at a temperature above 60°C and below 150°C, particularly preferably at a temperature above 80°C and below 120°C. This reactive solution reacts. The solvent can contain, for example, 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; ethyl acetate and butyl acetate , Cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, diethylene glycol monoethyl ether Acetate esters such as acid esters and propylene glycol monomethyl ether acetate; and dialkyl glycol ethers. The thermal polymerization inhibitor contains, for example, at least one of hydroquinone and hydroquinone monomethyl ether. The catalyst can contain, for example, at least one component selected from the group consisting of: tertiary amines such as benzyldimethylamine and triethylamine; trimethylbenzylammonium chloride, methyl Quaternary ammonium salts such as triethyl ammonium chloride; triphenyl phosphine; and, triphenyl stibine.

In particular, it is preferable that the catalyst contains triphenylphosphine. That is, it is preferable to react the epoxy compound (a1) with the carboxylic acid (a2) in the presence of triphenylphosphine. At this time, the ring-opening addition reaction of the epoxy group in the epoxy compound (a1) and the carboxylic acid (a2) can be particularly promoted, so as to achieve a reaction rate (conversion rate) of 95% or more, 97% or more, or approximately 100% . In addition, the occurrence of ion migration can be suppressed in the layer containing the cured product of the photosensitive resin composition, and the insulation of the layer containing the cured product can be improved.

When the epoxy compound (a1) is reacted with the carboxylic acid (a2), the amount of the carboxylic acid (a2) is preferably 0.5 mol or more with respect to 1 mol of epoxy group of the epoxy compound (a1) And within the range of 1.2 mol or less. In this case, the excellent photosensitivity and stability of the photosensitive resin composition can be obtained. From the same viewpoint, the amount of the unsaturated group-containing carboxylic acid (a2-1) is preferably 0.5 mol or more and 1.2 mol or less with respect to 1 mol of epoxy group of the epoxy compound (a1) In the range. Or, when the carboxylic acid (a2) contains a carboxylic acid other than the unsaturated group-containing carboxylic acid (a2-1), the unsaturated group-containing carboxylic acid is based on 1 mole of epoxy group of the epoxy compound (a1) The amount of (a2-1) may be in the range of 0.5 mol or more and 0.95 mol or less. In addition, when the carboxylic acid (a2) contains the polybasic acid (a2-2), the amount of the polybasic acid (a2-2) is preferably 0.025 mol relative to 1 mol of epoxy group of the epoxy compound (a1). In the range of more than ear and 0.25 mol or less. In this case, the excellent photosensitivity and stability of the photosensitive resin composition can be obtained.

It is also preferable to react the epoxy compound (a1) and the carboxylic acid (a2) in a state where the air is bubbling. At this time, the addition polymerization reaction of the unsaturated group can be suppressed, thereby suppressing the increase in the molecular weight of the intermediate and the gelation of the solution of the intermediate. In addition, it is possible to suppress excessive coloration of the final product, which is the carboxyl group-containing resin (A1).

The intermediate obtained in this way has a hydroxyl group produced by the reaction of the epoxy group in the epoxy compound (a1) and the carboxyl group in the carboxylic acid (a2).

The acid anhydride (a3) preferably contains an acid monoanhydride. Acid mono anhydride is a compound with one acid anhydride group.

Acid monoanhydrides can contain dicarboxylic acid anhydrides. The acid monoanhydride can contain, for example, one or more compounds selected from the group consisting of: 1,2,3,6-tetrahydrophthalic anhydride, phthalic anhydride, succinic anhydride, methyl Succinic anhydride, maleic anhydride, citraconic anhydride, glutaric anhydride, itaconic anhydride, methyltetrahydrophthalic anhydride, methyl nadic acid anhydride, hexahydrophthalic anhydride, cyclic Hexane-1,2,4-tricarboxylic acid-1,2-anhydride, and methylhexahydrophthalic anhydride. In particular, it is preferable that the acid monoanhydride contains 1,2,3,6-tetrahydrophthalic anhydride. In this case, the good developability of the photosensitive resin composition can be ensured, and the insulation of the cured product of the photosensitive resin composition can be improved. Relative to all acid monoanhydrides, 1,2,3,6-tetrahydrophthalic anhydride is preferably in the range of 20 mol% or more and 100 mol% or less, and more preferably 40 mol% In the range of% or more and 100 mol% or less, it is not limited to these ranges.

The acid anhydride (a3) preferably contains an acid dianhydride. Acid dianhydride is a compound with two acid anhydride groups. The acid dianhydride can contain an anhydride of tetracarboxylic acid. The acid dianhydride can contain, for example, at least one compound selected from the group consisting of: 1,2,4,5-pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, methylcyclohexene Tetracarboxylic dianhydride, tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, ethylene tetracarboxylic dianhydride, 9,9'-bis(3,4-dicarboxyphenyl) dianhydride , Glycerin bis (trimellitic anhydride) monoacetate, ethylene glycol bis (trimellitic anhydride), 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 1, 3,3a,4,5,9b-hexahydro-5 (tetrahydro-2,5-dioxo-3-furyl) naphtho[1,2-c]furan-1,3-dione, 1,2,3,4-butanetetracarboxylic dianhydride, and 3,3',4,4'-biphenyltetracarboxylic dianhydride. The acid dianhydride preferably contains an acid dianhydride having an aromatic ring. In particular, it is preferable that the acid dianhydride contains 3,3',4,4'-biphenyltetracarboxylic dianhydride. In this case, the good developability of the photosensitive resin composition can be ensured, and the insulation of the cured product of the photosensitive resin composition can be improved. In addition, the transparency of the photosensitive resin composition can be improved, and the resolution can be improved. With respect to the total acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride is preferably in the range of 20 mol% or more and 100 mol% or less, and more preferably 40 mol% It exists in the range of ear% or more and 100 mol% or less, but it is not limited to these ranges.

When reacting an intermediate and acid anhydride (a3), a well-known method can be adopted. For example, an acid anhydride (a3) is added to the solvent solution of the intermediate, and a thermal polymerization inhibitor and a catalyst are further added as necessary, and stirred and mixed to obtain a reactive solution. The carboxyl group-containing resin (A1) can be obtained by the following method: According to a conventional method, the reactive solution is more preferably reacted at a temperature of 60°C or more and 150°C or less, and particularly preferably 80°C or more and 120°C The following temperature allows the reactive solution to react. As the solvent, catalyst, and polymerization inhibitor, suitable solvents, catalysts, and polymerization inhibitors can be used, and the solvents, catalysts, and polymerization inhibitors used in the synthesis of intermediates can also be used directly.

In particular, it is preferable that the catalyst contains triphenylphosphine. That is, it is preferable to react the intermediate and acid anhydride (a3) in the presence of triphenylphosphine. At this time, the reaction between the secondary hydroxyl group in the intermediate and the acid anhydride (a3) can be particularly promoted, and a reaction rate (conversion rate) of 90% or more, 95% or more, 97% or more, or approximately 100% can be achieved. In addition, the occurrence of ion migration can be suppressed in the layer containing the cured product of the photosensitive resin composition, and the insulation of the layer containing the cured product can be further improved.

It is also preferable to react the intermediate and acid anhydride (a3) in a state where the air is bubbling. At this time, it is possible to suppress an excessive increase in the molecular weight of the produced carboxyl group-containing resin (A1), and thereby it is possible to particularly improve the developability of the photosensitive resin composition with an alkaline aqueous solution.

The carboxyl group-containing resin (A) may contain a carboxyl group-containing resin which has an aromatic ring and does not have photopolymerization. The carboxyl group-containing resin which has an aromatic ring and does not have photopolymerization properties, for example, contains a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group. An ethylenically unsaturated compound with a carboxyl group can contain the following compounds: acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≒2) monoacrylate, phthalic acid 2-(meth)acrylic acid Ethyloxyethyl, 2-(meth)acryloyloxyethyl 2-hydroxyethyl phthalate and the like. The ethylenically unsaturated compound having a carboxyl group can also contain reactants of pentaerythritol triacrylate, pentaerythritol trimethacrylate, etc. and dibasic acid anhydride. Ethylene unsaturated monomers may further contain linear or branched aliphatic or alicyclic (among which, part of the ring may have unsaturated bonds) (meth)acrylates and other ethylenic unsaturated monomers that do not have a carboxyl group Compound.

The carboxyl group-containing resin (A) may contain resins other than the carboxyl group-containing resin (A1), that is, a carboxyl group-containing resin that does not have a bisphenol sulfonate skeleton (hereinafter also referred to as carboxyl group-containing resin (A2)).

The carboxyl group-containing resin (A2) can contain, for example, a compound having a carboxyl group and not having photopolymerization properties (hereinafter referred to as (A2-1) component). The component (A2-1) is, for example, a polymer containing an ethylenically unsaturated monomer, and the ethylenically unsaturated monomer contains an ethylenically unsaturated compound having a carboxyl group. The ethylenically unsaturated compound having a carboxyl group can contain the following compounds: acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≒2) monoacrylate and the like. The ethylenically unsaturated compound having a carboxyl group can also contain reactants of pentaerythritol triacrylate, pentaerythritol trimethacrylate, etc. and dibasic acid anhydride. The ethylenically unsaturated monomer may further contain the following ethylenically unsaturated compounds that do not have a carboxyl group: 2-(meth)acryloyloxyethyl phthalate, 2-(meth)propylene phthalate Ethyloxyethyl 2-hydroxyethyl, linear or branched aliphatic or cycloaliphatic (wherein part of the ring may have an unsaturated bond) (meth)acrylate, etc.

The carboxyl group-containing resin (A2) may contain a compound having a carboxyl group and an ethylenically unsaturated group (hereinafter referred to as (A2-2) component). In addition, the carboxyl group-containing resin (A2) may contain only the component (A2-2). The component (A2-2) contains a resin (hereinafter referred to as the first resin (x)), which is, for example, a reactant of an intermediate and compound (x3), and the intermediate has two or more rings in one molecule A reaction product of an epoxy compound (x1) of an oxy group and an ethylenically unsaturated compound (x2), and the compound (x3) is at least one selected from the group of polycarboxylic acids and anhydrides thereof. The first resin (x) can, for example, react the epoxy group in the epoxy compound (x1) with the carboxyl group in the ethylenically unsaturated compound (x2), and then add the compound (x3) to the obtained intermediate obtain. The epoxy compound (x1) can contain an appropriate epoxy compound such as a cresol novolak type epoxy compound, a phenol novolak type epoxy compound, and a biphenol novolak type epoxy compound. In particular, the epoxy compound (x1) preferably contains at least one compound selected from the group of a biphenol novolak type epoxy compound and a cresol novolak type epoxy compound. The epoxy compound (x1) may contain only the biphenol novolak type epoxy compound, or may contain only the cresol novolak type epoxy compound. At this time, the epoxy compound (x1) contains an aromatic ring in the main chain, and therefore it is possible to significantly reduce the extent to which the cured product of the photosensitive resin composition is corroded by an oxidizing agent containing potassium permanganate or the like. The epoxy compound (x1) may contain a polymer of the ethylenically unsaturated compound (z). The ethylenically unsaturated compound (z) contains, for example, a compound having an epoxy group (z1) such as glycidyl (meth)acrylate, or further contains 2-(meth)acryloyloxyethyl phthalate, etc. Compound without epoxy group (z2). 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: polycarboxylic acids such as phthalic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid; and, Anhydrides of these polycarboxylic acids. In particular, the compound (x3) preferably contains at least one polycarboxylic acid selected from the group of phthalic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid.

The component (A2-2) may also contain a resin (called the second resin (y)), which is a reaction product of a polymer of an ethylenically unsaturated monomer and an ethylenically unsaturated compound having an epoxy group, The ethylenically unsaturated monomer contains an ethylenically unsaturated compound having a carboxyl group. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound that does not have a carboxyl group. The second resin (y) can be obtained by reacting an ethylenically unsaturated compound having an epoxy group with a part of the carboxyl group in the polymer. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound that does not have a carboxyl group. An ethylenically unsaturated compound having a carboxyl group, including, for example, the following compounds: acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≒2) monoacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, etc. . An ethylenically unsaturated compound that does not have a carboxyl group, including, for example, the following compounds: 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl phthalate 2 -Hydroxyethyl, linear or branched aliphatic or alicyclic (wherein part of the ring may have an unsaturated bond) (meth)acrylate, etc. The ethylenically unsaturated compound having an epoxy group preferably contains glycidyl (meth)acrylate.

The carboxyl group-containing resin (A) contains only the carboxyl group-containing resin (A1), only the carboxyl group-containing resin (A2), or contains the carboxyl group-containing resin (A1) and the carboxyl group-containing resin (A2). In order to obtain high transparency of the photosensitive resin composition and to reduce the dielectric loss tangent of the cured product of the photosensitive resin composition, the carboxyl group-containing resin (A) preferably contains 30% by mass or more of the carboxyl group-containing resin (A1 ), more preferably 60% by mass or more, and still more preferably 100% by mass.

The content of the carboxyl group-containing resin (A) relative to the solid content of the photosensitive resin composition is preferably in the range of 5% by mass or more and 85% by mass, more preferably 10% by mass or more and 75% by mass The following range is more preferably in the range of 26% by mass or more and 60% by mass or less, and particularly preferably in the range of 30% by mass or more and 45% by mass or less. In addition, the solid content means the total amount of all components remaining after removing volatile components such as a solvent from the photosensitive resin composition.

The solid acid value of the carboxyl group-containing resin (A) is preferably in the range of 40 mgKOH/g or more and 160 mgKOH/g or less. In this case, the stability of the photosensitive resin composition can be particularly improved. It is more preferable if the acid value is in the range of 60 mgKOH/g or more and 140 mgKOH/g or less; it is even more preferable if the acid value is in the range of 80 mgKOH/g or more and 135 mgKOH/g or less; if the acid value is more than 90 mgKOH/g and The range of 130 mgKOH/g or less is particularly preferred.

The unsaturated compound (B) can impart photocurability to the photosensitive resin composition. The unsaturated compound (B) can contain, for example, at least one compound selected from the group consisting of: monofunctional (meth)acrylates such as 2-hydroxyethyl (meth)acrylate; and diethylenedi Alcohol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate Acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ε-caprolactone modified pentaerythritol hexaacrylate, tricyclodecane dimethanol di(meth)acrylate, etc. Functional (meth)acrylate.

In particular, the unsaturated compound (B) preferably contains a trifunctional compound, that is, a compound having 3 unsaturated bonds in one molecule. At this time, when the film 4 formed of the photosensitive resin composition is exposed and developed, the resolution can be improved, and the developability of the photosensitive resin composition with an alkaline aqueous solution can be particularly improved. The trifunctional compound can contain, for example, at least one compound selected from the group consisting of: trimethylolpropane tri(meth)acrylate, ethylene oxide (EO) modified trimethylolpropane tri(methyl) Base) acrylate, pentaerythritol tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, ε-caprolactone modified ginseng (2-acryloyloxyethyl) iso Cyanuric acid ester, and ethoxylated glycerol tri(meth)acrylate.

The unsaturated compound (B) also preferably contains a phosphorus-containing compound (a phosphorus-containing unsaturated compound). In this case, the flame retardancy of the cured product of the photosensitive resin composition can be improved. The phosphorus-containing unsaturated compound can contain, for example, at least one compound selected from the group consisting of: 2-methacryloxyethyl phosphate (as a specific example, a product manufactured by Kyoeisha Chemical Co., Ltd.) Models LIGHT ESTER P-1M, and LIGHT ESTER P-2M), 2-propenyloxyethyl phosphate (as a specific example, product model LIGHT ACRYLATE P-1A manufactured by Kyoeisha Chemical Co., Ltd.), diphenyl phosphate 2-methacryloxy ethyl ester (as a specific example, the product model MR-260 manufactured by Dahachi Industrial Co., Ltd.), and the HFA series manufactured by Showa Polymer Co., Ltd. (as a specific example, dipentaerythritol The addition reactant of hexaacrylate and HCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) is the product model HFA-6003 and HFA-6007, caprolactone modified The addition reactant of high-quality dipentaerythritol hexaacrylate and HCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) is the product model HFA-3003 and HFA-6127, etc.) .

The unsaturated compound (B) may contain a prepolymer. The prepolymer can contain, for example, at least one compound selected from the group consisting of: first polymerizing monomers with ethylenically unsaturated bonds, and then adding ethylenically unsaturated groups to obtain prepolymers ; And, oligomeric (meth)acrylate prepolymers. The oligomeric (meth)acrylate prepolymers can contain, for example, at least one component selected from the group consisting of epoxy (meth)acrylate, polyester (meth)acrylate, Amino ester (meth)acrylate, alkyd resin (meth)acrylate, silicone resin (meth)acrylate, and spirane resin (meth)acrylate.

The photopolymerization initiator (C) contains, for example, an oxyphosphine oxide-based photopolymerization initiator. That is, the photosensitive resin composition contains, for example, an oxyphosphine oxide-based photopolymerization initiator. At this time, when the photosensitive resin composition is exposed with ultraviolet rays, high photosensitivity can be imparted to the photosensitive resin composition. In addition, the occurrence of ion migration can be suppressed in the layer containing the cured product of the photosensitive resin composition, thereby further improving the insulation reliability of the layer.

In addition, the phosphine oxide-based photopolymerization initiator does not easily hinder the electrical insulation of the cured product. Therefore, by exposing and curing the photosensitive resin composition, a cured product excellent in electrical insulation can be obtained, and this cured product is suitable as the interlayer insulating layer 7.

The phosphine oxide-based photopolymerization initiator can contain, for example, at least one component selected from the group consisting of 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, Monophosphine oxide-based photopolymerization initiators such as 2,4,6-trimethylbenzyl-phenyl-phosphonic acid ethyl ester; and, bis-(2,6-dichlorobenzyl) Phenyl phosphine oxide, bis-(2,6-dichlorobenzyl)-2,5-dimethylphenyl phosphine oxide, bis-(2,6-dichlorobenzyl)-4-propane Phenyl phosphine oxide, bis-(2,6-dichlorobenzyl)-1-naphthyl phosphine oxide, bis-(2,6-dimethoxybenzyl) phenyl phosphine oxide, double -(2,6-Dimethoxybenzyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzyl)-2,5 -Dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzyl)phenylphosphine oxide, (2,5,6-trimethylbenzyl)-2,4 , 4-trimethylpentyl phosphine oxide and other bis-amino phosphine oxide-based photopolymerization initiators. In particular, it is preferable that the acylphosphine oxide-based photopolymerization initiator contains 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, and it is also preferable that the acylphosphine oxide-based photopolymerization initiator contains 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide. The agent only contains 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide.

The photopolymerization initiator (C) preferably contains a hydroxyketone-based photopolymerization initiator in addition to the oxyphosphine oxide-based photopolymerization initiator. That is, the photosensitive resin composition preferably contains a hydroxyketone-based photopolymerization initiator. In this case, compared to the case where the hydroxyketone-based photopolymerization initiator is not contained, the photosensitive resin composition can be imparted with higher sensitivity. With this, when the coating film formed of the photosensitive resin composition is irradiated with ultraviolet rays to be cured, the coating film can be sufficiently cured from the surface to the deep part. Examples of hydroxyketone-based photopolymerization initiators 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-propanyl)-benzyl] Phenyl}-2-methyl-propan-1-one, and 2-hydroxy-2-methyl-1-phenyl-propan-1-one.

The mass ratio of the phosphine oxide-based photopolymerization initiator to the hydroxyketone-based photopolymerization initiator is preferably in the range of 1:0.01 to 1:10. At this time, the curability near the surface of the coating film formed of the photosensitive resin composition and the curability in the deep part can be improved in a balanced manner. Here, since the photosensitive resin composition contains the organic filler (E), the organic filler (E) may cause light scattering in the photosensitive resin composition during exposure. At this time, there may be a problem that good developability cannot be obtained from the photosensitive resin composition. From this point of view, in order to improve the resolution and obtain good developability by the photosensitive resin composition, the mass ratio of the phosphine oxide-based photopolymerization initiator to the hydroxyketone-based photopolymerization initiator is particularly preferred. In the range of 1:0.01 to 1:1.

The photopolymerization initiator (C) also preferably contains a photopolymerization initiator having a benzophenone skeleton. That is, it is also preferable that the photosensitive resin composition contains an acylphosphine oxide-based photopolymerization initiator and a photopolymerization initiator having a benzophenone skeleton, or the photosensitive resin composition contains an acylphosphine oxide-based photopolymerization initiator. A photopolymerization initiator, a hydroxyketone-based photopolymerization initiator, and a photopolymerization initiator having a benzophenone skeleton. At this time, when the coating film formed of the photosensitive resin composition is partially exposed and then developed, the resolution of the unexposed portion is suppressed, so that the resolution becomes particularly high. Therefore, a cured product of the photosensitive resin composition with a very fine pattern can be formed. In particular, when the interlayer insulating layer 7 of the multilayer printed wiring board 20 is made of a photosensitive resin composition, and the interlayer insulating layer 7 is provided with a small diameter hole 6 for the through hole 10 by photolithography (photolithography) In this case (see Fig. 1 C and Fig. 1 D), the hole 6 with a small diameter can be formed accurately and easily. Examples of the photopolymerization initiator having a benzophenone skeleton include bis(diethylamino)benzophenone.

The amount of the photopolymerization initiator having a benzophenone skeleton relative to the phosphine oxide-based photopolymerization initiator is preferably in the range of 0.5% by mass or more and 20% by mass or less. If the amount of the photopolymerization initiator having a benzophenone skeleton is 0.5% by mass or more relative to the phosphine oxide-based photopolymerization initiator, the resolution becomes particularly high. In addition, if the amount of the photopolymerization initiator having a benzophenone skeleton is 20% by mass or less relative to the phosphine oxide-based photopolymerization initiator, the photopolymerization initiator having a benzophenone skeleton The electrical insulation of the cured product of the photosensitive resin composition is not easily hindered. From the same viewpoint, the amount of bis(diethylamino)diphenyl ketone relative to the phosphine oxide-based photopolymerization initiator is preferably in the range of 0.5% by mass to 20% by mass Inside. Here, since the photosensitive resin composition contains the organic filler (E), the organic filler (E) may cause light scattering in the photosensitive resin composition during exposure. In this case, there may be a problem that good developability cannot be obtained from the photosensitive resin composition. From this point of view, in order to obtain good developability from the photosensitive resin composition, the amount of the photopolymerization initiator having a benzophenone skeleton relative to the phosphine oxide-based photopolymerization initiator is particularly preferable It is in the range of 1% by mass or more and 18% by mass or less. From the same viewpoint, the amount of bis(diethylamino)diphenyl ketone relative to the phosphine oxide-based photopolymerization initiator is particularly preferably in the range of 1% by mass or more and 18% by mass Inside.

The photopolymerization initiator (C) is not limited to the above-mentioned preferred examples, and can contain at least one component appropriately selected from known compounds.

The photosensitive resin composition may further contain a known photopolymerization accelerator, sensitizer, and the like. The photosensitive resin composition can contain, for example, at least one component selected from the group consisting of: benzoin and its alkyl ethers; acetophenones such as acetophenone and benzil dimethyl ketal; 2 -Anthraquinones such as methylanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-Diisopropylthioxanthone and other thioxanthones; diphenyl ketones, 4-benzyl-4'-methyldiphenyl sulfide and other diphenyl ketones; 2 , 4-Diisopropyl dibenzopyrone and other dibenzopiperanones (xanthone); and, 2-hydroxy-2-methyl-1-phenyl-propan-1-one and other α-hydroxyl Ketones; 2-methyl-1-[4-(methylthio)phenyl]-2-(N-morpholinyl)-1-acetone and other nitrogen-containing compounds. The photosensitive resin composition may contain ethyl p-dimethylbenzoate, isoamyl p-dimethylaminobenzoate, and 2-dimethylamine benzoate in addition to the photopolymerization initiator (C). Known photopolymerization accelerators or sensitizers such as tertiary amines such as ethyl ester. The photosensitive resin composition may contain at least one of a photopolymerization initiator for visible light exposure and a photopolymerization initiator for near-infrared exposure as necessary. The photosensitive resin composition may contain, in addition to the photopolymerization initiator (C), a sensitizer used in the laser exposure method, that is, 7-diethylamino-4-methylcoumarin, etc. Bean derivatives, carbocyanine pigments, xanthene pigments, etc.

The epoxy compound (D) can impart thermosetting properties to the photosensitive resin composition. The epoxy compound (D) preferably has at least two epoxy groups in one molecule. The epoxy compound (D) may be a poorly solvent-soluble epoxy compound or a general solvent-soluble epoxy compound. The epoxy compound (D) preferably contains, for example, one or more components selected from the group consisting of: phenol novolac type epoxy resin (as a specific example, the product model EPICLON N manufactured by DIC Co., Ltd. -775), cresol novolak type epoxy resin (as a specific example, product model EPICLON N-695 manufactured by DIC Co., Ltd.), bisphenol A novolak type epoxy resin (as a specific example, manufactured by DIC Co., Ltd. The product model EPICLON N-865), bisphenol A type epoxy resin (as a specific example, the product model jER1001 manufactured by Mitsubishi Chemical Co., Ltd.), and bisphenol F type epoxy resin (as a specific example, Mitsubishi Chemical Co., Ltd. Manufactured product model jER4004P), bisphenol S type epoxy resin (as a specific example, DIC Co., Ltd. product model EPICLON EXA-1514), bisphenol AD type epoxy resin, biphenyl type epoxy resin (as a specific example For example, product model YX4000 manufactured by Mitsubishi Chemical Co., Ltd., biphenol novolac type epoxy resin (as a specific example, product model NC-3000 manufactured by Nippon Kayaku Co., Ltd.), hydrogenated bisphenol A epoxy resin (As a specific example, the product model ST-4000D manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), naphthalene type epoxy resin (as a specific example, the product model EPICLON HP-4032, EPICLON HP-4700 manufactured by DIC Co., Ltd.) EPICLON HP-4770), hydroquinone type epoxy resin (as a specific example, product model YDC-1312 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), tertiary butylcatechol type epoxy resin (as a specific example , DIC Co., Ltd. product model EPICLON HP-820), dicyclopentadiene type epoxy resin (as a specific example, DIC Co., Ltd. product model EPICLON HP-7200), adamantane type epoxy resin (as Specific examples include the product model ADAMANTATE XE-201 manufactured by Idemitsu Kosan Co., Ltd., the bisphenol epoxy resin (as a specific example, the product model YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), and biphenyl Ether type epoxy resin (as a specific example, product model YSLV-80DE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), tetra (hydroxyphenyl) ethane type crystalline epoxy resin (as a specific example, Nippon Kayaku Co., Ltd. Co., Ltd. product model GTR-1800), epoxy resin with a bisphenol pyridine skeleton (as a specific example, epoxy resin with structure (S7)), rubber-like core-shell polymer modified bisphenol A epoxy Resin (as a specific example, product model MX-156 manufactured by Kaneka Co., Ltd.), rubber-like core-shell polymer modified bisphenol F epoxy resin (as a specific example, product model MX manufactured by Kaneka Co., Ltd. - 136), and special bifunctional epoxy resins (as specific examples, product models YL7175-500 and YL7175-1000 manufactured by Mitsubishi Chemical Co., Ltd.; product models EPICLON TSR-960 and EPICLON TER- manufactured by DIC Co., Ltd.) 601, EPICLON TSR-250-80BX, EPICLON 1650-75MPX, EPICLON EXA-4850, EPICLON EXA-4816, EPICLON EXA-4822, and EPICLON EXA-9726; product model YSLV-120TE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. ).

The epoxy compound (D) preferably contains a crystalline epoxy resin. In this case, the developability of the photosensitive resin composition can be improved. In addition, the crystalline epoxy resin refers to an epoxy resin having a melting point. The crystalline epoxy resin can contain, for example, at least one component selected from the group consisting of: triglycidyl isocyanurate (1,3,5-reference (2,3-epoxypropyl) )-1,3,5-triazine-2,4,6(1H,3H,5H)-trione), hydroquinone type crystalline epoxy resin (as a specific example, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. YDC-1312), biphenyl type crystalline epoxy resin (as a specific example, product model YX4000 manufactured by Mitsubishi Chemical Co., Ltd.), diphenyl ether type crystalline epoxy resin (as a specific example, Nippon Product model YSLV-80DE manufactured by Iron & Sumikin Chemical Co., Ltd., bisphenol-type crystalline epoxy resin (as a specific example, product name YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), Si (hydroxyphenyl) ) Ethane type crystalline epoxy resin (as a specific example, the product model GTR-1800 manufactured by Nippon Kayaku Co., Ltd.), bisphenol pyridine type crystalline epoxy resin (as a specific example, a ring with the structure (S7) Oxygen resin).

The amount of the crystalline epoxy resin relative to the epoxy compound (D) is preferably in the range of 10% by mass or more and 100% by mass or less, and more preferably in the range of 30% by mass or more and 100% by mass or less , And more preferably within the range of 35% by mass or more and 100% by mass or less. At this time, in the step before the thermosetting of the photosensitive resin composition, the thermosetting reaction between the carboxyl group-containing resin and the epoxy resin can be suppressed, and the developability can be improved.

In particular, the crystalline epoxy resin preferably contains a crystalline epoxy resin having a melting point of 110°C or less. That is, the epoxy compound (D) preferably contains a crystalline epoxy resin having a melting point of 110°C or less. In this case, the developability of the photosensitive resin composition with an alkaline aqueous solution can be particularly improved. A crystalline epoxy resin having a melting point of 110°C or less can contain, for example, at least one component selected from the group consisting of: biphenyl type epoxy resin (as a specific example, a product model manufactured by Mitsubishi Chemical Co., Ltd.) YX4000), biphenyl ether type epoxy resin (as a specific example, product model YSLV-80DE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), and bisphenol type epoxy resin (as a specific example, Nippon Steel & Sumikin Chemical Co., Ltd. The product model YSLV-80XY manufactured by Co., Ltd.).

The epoxy compound (D) may contain triglycidyl isocyanurate. In particular, triglycidyl isocyanurate is preferably: a β-body having a structure in which three epoxy groups are bonded in the same direction relative to the s-triazine ring skeleton plane; or , Preferably: a mixture of the β-body and the α-body, the α-body has an epoxy group bonded in a direction different from the other two epoxy groups relative to the s-triazine ring skeleton plane structure.

The crystalline epoxy resin also preferably contains a crystalline epoxy resin having a melting point of less than 100°C. That is, the epoxy compound (D) also preferably contains a crystalline epoxy resin having a melting point of less than 100°C. In this case, the developability of the photosensitive resin composition can be further improved. In addition, the crystalline epoxy resin having a melting point of less than 100°C has high compatibility with components other than the epoxy resin (D) in the photosensitive resin composition, solvents, etc., so it is easy to be dispersed in the photosensitive resin composition In and homogenize. Furthermore, if the photosensitive resin composition contains a crystalline epoxy resin with a melting point of less than 100°C, crystallization is unlikely to occur even at low temperatures. Therefore, it is possible to impart high storage stability to the photosensitive resin composition. Furthermore, the crosslinking reaction between the carboxyl group and the epoxy group in the photosensitive resin composition can be suppressed at low temperatures, and therefore the good developability of the photosensitive resin composition can be maintained, and high storage stability can be imparted to the photosensitive resin composition .

A crystalline epoxy resin with a melting point lower than 100°C can contain, for example, at least one component selected from the group consisting of: biphenyl ether type epoxy resin (as a specific example, Nippon Steel & Sumikin Chemical Co., Ltd. The company’s product model YSLV-80DE), bisphenol-type epoxy resin (as a specific example, Nippon Steel & Sumikin Chemical Co., Ltd. product model YSLV-80XY), and an epoxy resin with a bisphenol skeleton (as a specific example) A specific example is epoxy resin with structure (S7)).

When the epoxy compound (D) contains a crystalline epoxy resin having a melting point of less than 100°C, the crystalline epoxy resin having a melting point of less than 100°C contains 1 equivalent of carboxyl groups contained in the carboxyl group-containing resin (A) The equivalent weight of the epoxy group is preferably in the range of 0.2 or more and 2.0 or less, more preferably in the range of 0.25 or more and 1.7 or less, and even more preferably in the range of 0.3 or more and 1.5 or less.

The epoxy compound (D) may contain phosphorus-containing epoxy resin. In this case, the flame retardancy of the cured product of the photosensitive resin composition can be improved. Phosphorus-containing epoxy resins, for example, phosphoric acid modified bisphenol F type epoxy resin (as specific examples, product models EPICRON EXA-9726 and EPICRON EXA-9710 manufactured by DIC Co., Ltd.), Nippon Steel & Sumikin Chemical Co., Ltd. The company's product model Epotohto FX-305 and so on.

The photosensitive resin composition preferably further contains an organic filler (E). In this case, the adhesion between the interlayer insulating layer 7 and the conductor layer 8 can be further improved. The organic filler (E) can also improve the thixotropy of the photosensitive resin composition and improve the stability (especially storage stability).

The organic filler (E) preferably has a polar group. In this case, the adhesion between the interlayer insulating layer 7 and the conductor layer 8 can be particularly improved. In particular, the polar group preferably includes at least one group selected from the group consisting of a carboxyl group, an amino group and a hydroxyl group. In this case, the adhesion can be particularly improved.

In particular, when the polar group contains a carboxyl group, the developability of the cured product of the photosensitive resin composition can be improved, and when the photosensitive resin composition contains a crystalline epoxy compound, the crystalline epoxy compound can be increased in the photosensitive resin Solubility in the composition and prevents crystallization.

In particular, when the polar group contains a hydroxyl group, the dispersibility of the organic filler (E) in the photosensitive resin composition can be improved.

In particular, when the polar group contains an amine group, the reactivity of the carboxyl group-containing resin (A) and the epoxy compound (D) can be improved, thereby improving the acid resistance and alkali resistance of the cured film.

When the polar group of the organic filler (E) includes a carboxyl group, the acid value of the organic filler (E) is preferably in the range of 1 mgKOH/g or more and 60 mgKOH/g or less. If the acid value is less than 1 mgKOH/g, the stability of the photosensitive resin composition and the developability of the cured product may decrease. If the acid value is greater than 60 mgKOH/g, the moisture resistance reliability of the hardened product may decrease. The acid value of the organic filler (E) is more preferably 3 mgKOH/g or more, and more preferably 40 mgKOH/g or less.

When the polar group contains a carboxyl group, the organic filler (E) can be obtained by, for example, making acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, etc. have polymerizable unsaturation. The double-bonded carboxylic acid monomer is polymerized or cross-linked.

The organic filler (E) can be blended into the photosensitive resin composition in the state of a dispersion liquid, but is not limited thereto.

The organic filler (E) preferably contains a rubber component having a polar group. In this case, the polar group includes, for example, a carboxyl group, or a carboxyl group and a hydroxyl group. The rubber component can impart flexibility to the cured product of the photosensitive resin composition.

The rubber component can be made of resin. The rubber component preferably contains at least one polymer selected from the group consisting of: cross-linked acrylic rubber, cross-linked butadiene-acrylonitrile rubber (cross-linked NBR), cross-linked methyl methacrylate Ester-butadiene-styrene (cross-linked MBS) and cross-linked styrene-butadiene rubber (cross-linked SBR). In this case, the photosensitive resin composition can have high transparency and can improve the resolution. In addition, the rubber component can effectively impart flexibility to the cured product of the photosensitive resin composition. NBR, a copolymer of butadiene and acrylonitrile, is classified as nitrile rubber. MBS is a copolymer composed of methyl methacrylate, butadiene, and styrene, and is classified as a butadiene rubber. SBR, a copolymer of styrene and butadiene, is classified as styrene rubber.

Specific examples of the organic filler (E) provided as a dispersion include: product model XER-91-MEK manufactured by JSR Co., Ltd. (crosslinked rubber (NBR) with an average primary particle size of 0.07 μm and a carboxyl group) A methyl ethyl ketone dispersion with a concentration of 15% by weight with an acid value of 10.0 mgKOH/g), product models XER-32-MEK and XER-92 manufactured by JSR Co., Ltd., and product models XSK manufactured by JSR Co., Ltd. -500 (a dispersion of cross-linked rubber (SBR) with carboxyl and hydroxyl groups).

The organic filler (E) may contain components other than the rubber component. The components other than the rubber component can contain at least one component selected from the group consisting of acrylic resin particles having a carboxyl group and cellulose particles having a carboxyl group. The acrylic resin microparticles having a carboxyl group can contain at least one component selected from the group consisting of non-crosslinked styrene/acrylic resin microparticles and crosslinked styrene/acrylic resin microparticles. Specific examples of non-crosslinked styrene/acrylic resin fine particles include the product model FS-201 (average primary particle size of 0.5 μm) manufactured by Nippon Paint Industrial Co., Ltd. Specific examples of cross-linked styrene/acrylic resin particles include: product model MG-351 (average primary particle size 1.0μm) manufactured by Nippon Paint Industrial Co., Ltd. and product model BGK-001 (average primary particle size) The particle size is 1.0 μm).

When the polar group contains an amine group, the organic filler (E) contains, for example, at least one component selected from the group consisting of: melamine, dicyandiamide, imidazole-based compounds, methylguanamine, benzene Guanamine, melamine-phenol-formaldehyde resin; triazine compound, ethyldiamino-s-triazine, 2,4-diamino-s-triazine, 2,4-diamino-6-xylene Triazine derivatives such as s-triazine; thiazole-based compounds; and triazole-based compounds. When the polar group contains an amine group, the organic filler (E) preferably contains melamine particles. If the organic filler (E) contains melamine particles, the adhesion between the interlayer insulating layer 7 and the conductor layer 8 can be particularly improved.

The organic filler (E) can contain at least one component selected from the group consisting of the above-described components. In addition, the organic filler (E) can also contain components having polar groups other than the components described above.

The average primary particle size of the organic filler (E) is preferably 1 μm or less. In this case, the thixotropy of the photosensitive resin composition can be efficiently improved. Therefore, the stability of the photosensitive resin composition can be further improved. In addition, the average primary particle diameter of the organic filler (E) is, for example, 0.001 μm or more. The average primary particle size of the organic filler (E) is the median particle size (D50) measured by a laser diffraction particle size distribution analyzer. The average primary particle diameter of the organic filler (E) is preferably 0.1 μm or less. In this case, the stability of the photosensitive resin composition can be further improved, and scattering during exposure can be suppressed, so the resolution can be further improved.

The particle size of the organic filler (E) in the photosensitive resin composition is preferably 10 μm or less. In the photosensitive resin composition, the organic filler (E) may contain secondary particles formed by aggregation. At this time, the particle diameter of the organic filler (E) in the photosensitive resin composition means the particle diameter of particles including secondary particles. The particle size of the organic filler (E) in the photosensitive resin composition can be measured using a laser diffraction scattering type particle size distribution measuring device or an optical microscope. If the particle size of the organic filler (E) in the photosensitive resin composition is 10 μm or less, the organic filler (E) can be well dispersed in the photosensitive resin composition and the interlayer insulating layer 7, thereby being able to improve the interlayer The adhesion between the insulating layer 7 and the conductor layer 8. In addition, the stability of the photosensitive resin composition can be further improved, and the scattering during exposure can be suppressed, so the resolution can be further improved. The particle size of the organic filler (E) in the photosensitive resin composition is more preferably 5 μm or less, still more preferably 1 μm or less, and particularly preferably 0.5 μm or less. In addition, the particle size is, for example, 0.01 μm or more.

The photosensitive resin composition may contain an organic solvent. The organic solvent is used for the following purposes: liquefaction or varnishing of the photosensitive resin composition, adjustment of viscosity, adjustment of coatability, adjustment of film-forming properties, and the like.

The organic solvent can contain, for example, at least one compound selected from the group consisting of: ethanol, propanol, isopropanol, hexanol, ethylene glycol and other linear, branched, secondary or polyhydric alcohols; Ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; Swasol series (manufactured by Maruzen Petrochemical Company), Solvesso series (manufactured by ExxonMobil Chemical Company), etc. Petroleum aromatic series mixed solvents; celluloid, butyl cellulose and other celluloids; carbitol, butyl carbitol and other carbitols; propylene glycol methyl ether and other propylene glycol alkyl ethers; two Polypropylene glycol alkyl ethers such as propylene glycol methyl ether; acetates such as ethyl acetate, butyl acetate, cellophane acetate, and carbitol acetate; and dialkyl glycol ethers.

The amount of the components in the photosensitive resin composition is appropriately adjusted so that the photosensitive resin composition has photocurability and can be developed with an alkaline solution.

Relative to the solid content of the photosensitive resin composition, the amount of the carboxyl group-containing resin (A) is preferably in the range of 5 mass% or more and 85% by mass or less, and if it is 10 mass% or more and 75 mass% or less It is more preferable if it exists in the range of 30 mass% or more, and it is still more preferable if it exists in the range of 60 mass% or less. In addition, relative to the solid content of the photosensitive resin composition, the amount of the carboxyl group-containing resin (A1) is preferably in the range of 5 mass% or more and 85% by mass, and it is preferably 10 mass% or more and 75 mass%. The range of% or less is more preferable, and the range of 30 mass% or more and 60 mass% or less is still more preferable.

Relative to the carboxyl group-containing resin (A), the amount of the unsaturated compound (B) is preferably in the range of 1% by mass to 50% by mass, and in the range of 10% by mass to 45% by mass. It is more preferable, and it is still more preferable if it exists in the range of 21 mass% or more and 40 mass% or less.

The amount of the photopolymerization initiator (C) relative to the carboxyl group-containing resin (A) is preferably in the range of 0.1% by mass or more and 30% by mass or less, if it is in the range of 1% by mass or more and 25% by mass or less The inside is even better.

Regarding the amount of the epoxy compound (D), it is preferable that the total amount of equivalents of epoxy groups contained in the epoxy compound (D) is 0.7 or more with respect to 1 equivalent of carboxyl groups contained in the carboxyl group-containing resin (A) It is in the range of 2.5 or less, more preferably in the range of 0.7 or more and 2.3 or less, and even more preferably in the range of 0.7 or more and 2.0 or less. In addition, it is preferable that the total amount of equivalents of epoxy groups contained in the crystalline epoxy resin is in the range of 0.1 to 2.0 with respect to 1 equivalent of carboxyl groups contained in the carboxyl group-containing resin (A), if it is 0.2 It is more preferable in the range of the above and 1.9 or less, and it is still more preferable in the range of 0.3 or more and 1.5 or less. Alternatively, with respect to 1 equivalent of carboxyl groups contained in the carboxyl group-containing resin (A), the total amount of equivalents of epoxy groups contained in the crystalline epoxy resin may be in the range of 0.7 or more and 2.5 or less.

The amount of the organic filler (E) relative to 100 parts by mass of the carboxyl group-containing resin (A) is preferably in the range of 1 part by mass or more and 50 parts by mass or less. When the amount of the organic filler (E) is 1 part by mass or more, the adhesion between the interlayer insulating layer 7 and the conductor layer 8 becomes particularly high, and good copper plating density of the cured product of the photosensitive resin composition can be obtained. Fit. Moreover, when the amount of the organic filler (E) is 50 parts by mass or less, an excellent resolution of the photosensitive resin composition can be obtained. Moreover, by making the content of the organic filler (E) within the above-mentioned range, the thixotropy of the photosensitive resin composition can be improved, and the stability can be improved. The amount of the organic filler (E) is more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more. In addition, the amount of the organic filler (E) is more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less.

When the photosensitive resin composition contains an organic solvent, the amount of the organic solvent is preferably such that the organic solvent can quickly volatilize and disappear when the coating film formed by the photosensitive resin composition is dried, that is, It is adjusted so that the organic solvent does not remain in the dry film. In particular, the amount of the organic solvent relative to the entire photosensitive resin composition is preferably in the range of 0% by mass or more and 99.5% by mass or less, and more preferably in the range of 15% by mass or more and 60% by mass or less. good. Furthermore, the appropriate ratio of the organic solvent differs depending on the coating method and the like, and therefore, it is preferable to adjust the ratio appropriately depending on the coating method.

In addition, the solid content means the total amount of all components remaining after removing volatile components such as a solvent from the photosensitive resin composition.

The photosensitive resin composition may further contain components other than the above-mentioned components as long as the effects of the present embodiment are not impaired.

The photosensitive resin composition may contain an inorganic filler. In this case, it is possible to reduce the curing shrinkage of the film formed of the photosensitive resin composition. The inorganic filler can contain, for example, one or more materials selected from the group consisting of: barium sulfate, crystalline silica, nanosilica, carbon nanotubes, talc, bentonite, Hydrotalcite, aluminum hydroxide, magnesium hydroxide, and titanium dioxide. When the inorganic filler contains a white material such as titanium dioxide and zinc oxide, the photosensitive resin composition and its cured product can be whitened by the white material. When the photosensitive resin composition contains an inorganic filler, the amount of the inorganic filler relative to the carboxyl group-containing resin (A) is preferably more than 0% by mass and 300% by mass or less.

The photosensitive resin composition may contain at least one resin selected from the group consisting of: toluene diisocyanate series and morpholine diisocyanate series blocked with caprolactam, oxime, malonate, etc. , Isophorone diisocyanate series and hexamethylene diisocyanate series blocked isocyanate; melamine resin, n-butylated melamine resin, isobutylated melamine resin, butylated urea resin, butylated melamine-urea co-condensation resin, Amino resins such as benzoguanamine series co-condensation resins; various thermosetting resins other than the above; ultraviolet curable epoxy (meth)acrylates; p-bisphenol A type, phenol novolac type, cresol Novolac type, alicyclic type epoxy resin and other resins obtained by adding (meth)acrylic acid; and diallyl phthalate resin, phenoxy resin, urethane resin, fluororesin, etc. Polymer compounds.

The photosensitive resin composition may contain a curing agent for curing the epoxy compound (D). The hardener can contain, for example, at least one component selected from the group consisting of imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl Imidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole and other imidazole derivatives; dicyandiamide, benzene Methyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl -N,N-Dimethylbenzylamine and other amine compounds; hydrazine compounds such as hexadihydrazine and sebacadiazide; phosphorus compounds such as triphenylphosphine; acid anhydrides; phenols; mercaptans; Lewis acid amine complexes物; And, onium salt. Commercial products of these components are, for example: 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (all are the trade names of imidazole compounds) manufactured by Shikoku Chemical Co., Ltd.; manufactured by San-Apro Co., Ltd. U-CAT3503N, U-CAT3502T (all are the trade names of dimethylamine blocked isocyanate compounds); DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and their salts).

The photosensitive resin composition may contain an adhesiveness imparting agent. As the adhesion imparting agent, for example, the following s-triazine derivatives: guanamine, methylguanamine, benzoguanamine, and 2,4-diamino-6-methacryloxyethyl -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, etc.

The photosensitive resin composition may contain a rheology modifier. With the rheology modifier, the viscosity of the photosensitive resin composition can be easily optimized. As rheology modifiers, for example, polar polyamides in urea modification (product models BYK-430 and BYK-431 manufactured by BYK Japan Co., Ltd.), and polyhydroxycarboxamides (manufactured by BYK Japan Co., Ltd.) Product model BYK-405), modified urea (product model BYK-410, BYK-411, BYK-420 manufactured by BYK Japan Co., Ltd.), polymer urea derivative (product model BYK-made by BYK Japan Co., Ltd.) 415), urea-modified polyurethane (BYK Japan Co., Ltd. product model BYK-425), polyurethane (BYK Japan Co., Ltd. product model BYK-428), castor oil wax, polyethylene wax, polyamide Wax, bentonite, silica, silica gel, kaolin, clay.

The photosensitive resin composition may contain at least one component selected from the group consisting of: hardening accelerator; coloring agent; copolymer of polysiloxane, acrylate, etc.; leveling agent; silane Adhesion imparting agents such as coupling agents; thixotropic agents; polymerization inhibitors; antihalation agents; flame retardants; defoamers; antioxidants; surfactants; and, polymer dispersants.

The photosensitive resin composition is, for example, in a liquid form. When the photosensitive resin composition is in liquid form, the photosensitive resin composition can be prepared by, for example, blending the raw materials of the photosensitive resin composition as described above, and using, for example, a three-roll mill (three-roll mill). -Roll mill), ball mill (ball mill), sand mill (sand mill) and other known kneading methods for kneading. When the raw material of the photosensitive resin composition contains liquid components, low-viscosity components, etc., the photosensitive resin composition can be prepared by the following method: First, the raw materials except for the liquid components and low-viscosity components The other parts are kneaded, and then to the obtained mixture, liquid components, low-viscosity components, etc. are added and mixed. Also, for example, when all the raw materials are dispersed in a solvent, the photosensitive resin composition can be prepared by mixing the raw materials and stirring without kneading.

In consideration of storage stability, etc., the first agent can be prepared by mixing part of the components of the photosensitive resin composition, and the second agent can be prepared by mixing the remaining components. That is, the photosensitive resin composition may include a first agent and a second agent. At this time, for example, the first agent can be prepared by mixing and dispersing the unsaturated compound (B), a part of the organic solvent and the thermosetting component in the components of the photosensitive resin composition in advance, and then the photosensitive resin composition The rest of the components of the resin composition are mixed and dispersed to prepare the second agent. At this time, the required amount of the first agent and the second agent are mixed in a timely manner to prepare a mixed liquid, and the mixed liquid is hardened to obtain a hardened product.

The photosensitive resin composition may be a dry film. The dry film can be produced by, for example, coating the same liquid composition as the above-mentioned liquid photosensitive resin composition on an appropriate support such as polyester, and then drying. Thereby, it is possible to obtain a laminate (dry film with a support) provided with a dry film and a support for supporting the dry film.

The photosensitive resin composition preferably has the following properties: even the film 4 having a thickness of 25 μm can be developed with an aqueous sodium carbonate solution. At this time, a sufficiently thick interlayer insulating layer 7 can be produced from the photosensitive resin composition by photolithography. Of course, the interlayer insulating layer 7 having a thickness of less than 25 μm can also be produced from the photosensitive resin composition.

It can be confirmed by the following method whether the film 4 having a thickness of 25 μm can be developed with an aqueous sodium carbonate solution. The photosensitive resin composition is coated on an appropriate substrate to form a wet coating film, and then the wet coating film is heated at 80° C. for 40 minutes to form a film 4 having a thickness of 25 μm. In the state where the negative mask is directly attached to the film 4, the ^{film 4 is irradiated with ultraviolet rays at 500 mJ/cm 2} to perform exposure. The negative mask has a penetrating part that allows ultraviolet rays to pass through. , And the shielding part that shields ultraviolet rays. After exposure, the following treatment is performed: first spray 1% sodium carbonate (Na ₂ CO ₃ ) aqueous solution at 30°C on the film 4 at a spray pressure of 0.2 MPa for 90 seconds, and then spray pure water at a spray pressure of 0.2 MPa for 90 seconds . After observing the film 4 after this treatment, when the portion of the film 4 corresponding to the shielding portion is removed and no residue can be confirmed, it can be judged that the film 4 having a thickness of 25 μm can be developed with a sodium carbonate aqueous solution.

Hereinafter, an example of a method of manufacturing a multilayer printed wiring board 20 including an interlayer insulating layer 7 made of a photosensitive resin composition will be described with reference to FIGS. 1A to 1E.

In this method, the cured film 11 is produced by arranging the photosensitive resin composition on the printed wiring board 1 and photocuring the photosensitive resin composition. Then, the cured film 11 is first processed with an alkaline solution, and then the conductor layer 8 in contact with the cured film 11 is produced.

Specifically, first, as shown in FIG. 1A, a printed wiring board 1 is prepared. The printed wiring board 1 has, for example, at least an insulating layer 2 and a conductor line 3, and the conductor line 3 is located on the insulating layer 2.

As shown in FIG. 1B, the photosensitive resin composition is arranged on the printed wiring board 1 so as to cover the conductor line 3, and thereby the coating film 4 is produced.

When the film 4 is produced, when the photosensitive resin composition is in a liquid form, for example, the photosensitive resin composition is coated on the printed wiring board 1 to form a wet film. The coating method of the photosensitive resin composition is a well-known method, for example, a dipping method, a spray method, a spin coating method, a roll coating method, a curtain coating method, or a screen printing method. Then, in order to volatilize the organic solvent in the photosensitive resin composition, for example, the wet coating film is dried at a temperature in the range of 60° C. or more and 120° C. or less. In this way, the film 4 can be produced.

When the film 4 is produced, when the photosensitive resin composition is a dry film, for example, the dry film is laminated on the printed wiring board 1 while being supported by a support. In this state, pressure is applied to the dry film and the printed wiring board 1, and then the support is peeled from the dry film, whereby the dry film is transferred from the support to the printed wiring board 1. In this way, the film 4 composed of a dry film is provided on the printed wiring board 1.

Then, the film 4 is photocured to produce a cured film 11. For this reason, for example, as shown in FIG. 1C, the film 4 is partially hardened by exposing the film 4 to light. For this purpose, for example, a negative mask is attached to the film 4 first, and then the film 4 is irradiated with ultraviolet rays. The negative mask is provided with a penetrating portion that transmits ultraviolet rays and a shielding portion that shields ultraviolet rays, and the shielding portion is provided at a position consistent with the position of the through hole 10. The negative mask is, for example, a photo tool such as a mask film or a dry plate. The ultraviolet light source can be selected from the group consisting of, for example, chemical lamps, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, metal halide lamps, light-emitting diodes (LED ), g-line (436nm), h-line (405nm), i-line (365nm); and a combination of two or more of g-line, h-line, and i-line.

The exposure method may be a method other than the method using a negative mask. For example, the film 4 can be exposed by a direct drawing method in which ultraviolet rays emitted from a light source are irradiated to only the portion of the film 4 to be exposed. The light source suitable for direct drawing method can be selected from the following groups: high pressure mercury lamp, ultra high pressure mercury lamp, metal halide lamp, LED, g-line (436nm), h-line (405nm), i-line (365nm) ; And, a combination of two or more of g-line, h-line, and i-line.

When the photosensitive resin composition is a dry film, the dry film of the laminate can be first laminated on the printed wiring board 1, and then the support can be used to penetrate the dry film without peeling off the support. The coating film 4 is irradiated with ultraviolet rays, thereby exposing the coating film 4, and then the support is peeled off from the coating film 4 before the development process.

Furthermore, when the through-hole 10 is not provided in the multilayer printed wiring board 20, the entire coating film 4 may be photocured to produce the cured film 11 instead of partially photocuring the coating film 4.

Then, the cured film 11 is processed with an alkaline solution. When heat treatment is performed on the cured film 11 before the conductor layer 8 is produced, it is preferable to process the cured film 11 with an alkaline solution before the heat treatment.

The alkaline solution is, for example, an alkaline aqueous solution containing either or both of an alkali metal salt and an alkali metal hydroxide. The alkaline aqueous solution, more specifically, contains, for example, at least one component selected from the group consisting of sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium hydroxide , Potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, and lithium hydroxide. The solvent in the alkaline aqueous solution may be only water or a mixture of water and lower alcohols and other hydrophilic organic solvents. The pH value of the alkaline solution is preferably 8.5 or more and 14 or less. The pH of the alkaline solution is more preferably 9 or more, even more preferably 9.5 or more, and particularly preferably 10 or more. In addition, the pH of the alkaline aqueous solution is more preferably 13.5 or less, more preferably 13 or less, and particularly preferably 12.5 or less.

When the film 4 is partially photocured, the cured film 11 can be treated with an alkaline solution, and the unexposed portion 5 of the film 4 can be removed from the printed wiring board 1 with this alkaline solution. That is, the cured film 11 can be processed with the alkaline solution, and the development process can be performed with this alkaline solution. Thereby, as shown in FIG. 1D, the hole 6 can be provided at the position where the through hole 10 is to be formed.

The treatment with an alkaline solution is preferably carried out in a state where the reaction rate of the epoxy group based on the film 4 is 50% or less. The reaction rate of this epoxy group is based on the amount of epoxy groups in the film 4 before exposure. The treatment with alkaline solution is more preferably carried out in a state where the reaction rate of epoxy group is 40% or less, and it is still more preferable to be carried out in a state where the reaction rate of epoxy group is 30% or less. It is preferably carried out in a state where the reaction rate of the epoxy group is 20% or less. Furthermore, the reaction of epoxy groups, based on infrared (IR) spectrum 910cm ^- calculating the peak intensity derived from the epoxy group at ^1, the infrared spectrum is implemented by an infrared film 4 and the film 11 is cured Obtained by spectral analysis. In detail, the reaction of epoxy groups, based on the film 4 by the infrared spectroscopic analysis of the obtained IR spectrum 910cm ^- standardized value of the area of the peak at ¹ (S _0), and the alkaline solution by implementation of a cured film to infrared spectroscopic analysis after treatment 11 IR spectrum of the obtained 910cm ^{- 1} at the area of the peak of the normalized value (S _1), and is calculated using the following formula: (S ₀ -S ₁₎ ÷ S ₀ ×100(%). In addition, the normalized value (S ₀ ) and the normalized value (S ₁ ) are relative values based on the area of the following peaks in the IR spectrum: peaks that do not change even if the film 4 is exposed to light. For example 750cm ^- peak at ^1. I.e., normalized value (S _0), IR spectra obtained in 910cm 4 by the infrared spectroscopic analysis of the film ^- measured value of a peak area of ^a (P _0), and 750cm ^- peak area at ¹ The actual measured value (R ₀ ) has a relationship of _{S 0} =P ₀ /R _0. Further, the normalized value (S _1), IR spectrum of the obtained cured film 910cm by the infrared spectroscopic analysis of 11 ^- at the area of the peak ^measured value (P _1), and 750cm ^{- a} peak areas of The actual measured value (R ₁ ) has a relationship of _{S 1} =P ₁ /R _1.

The cured film 11 can be cleaned using a well-known chemical solution after the treatment with an alkaline solution and before the conductor layer 8 is produced. The cleaning treatment is preferably treatment that does not roughen the cured film 11. The cleaning treatment is, for example, a cleaning solution (a solution containing 40ml/L of Cleaner Securiganth 902 manufactured by Ato Technology Co., Ltd., 3ml/L of Cleaner Additive 902, 20g/L of NaOH) to cure the film 11 Perform cleaning. Then, the cured film 11 was immersed in an aqueous solution containing 100 g/L of sodium persulfate and 10 ml/L of sulfuric acid, followed by water washing.

Then, the conductor layer 8 in contact with the cured film 11 is produced. The conductor layer 8 is, for example, a conductor line made of metal such as copper. As described above, immediately before the production of the conductor layer (8), the arithmetic average roughness Ra specified by JIS B0601-2001 of the surface of the cured film (11) in contact with the conductor layer (8) is less than 150 nm. This can be easily achieved as long as the cured film 11 is made from the photosensitive resin composition by a normal method, for example, the method already described.

If the arithmetic average roughness Ra is less than 150 nm, the multilayer printed wiring board 20 can have good high frequency characteristics. The arithmetic average roughness Ra is preferably less than 100 nm, more preferably less than 80 nm, and particularly preferably less than 30 nm. In addition, this arithmetic average roughness Ra is, for example, 5 nm or more.

When the hole 6 is formed in the cured film 11, the through hole 10 is made by forming a perforated plating layer 9 on the inner side of the hole 6. Furthermore, in FIG. 1E, the perforated plating layer 9 has a cylindrical shape covering the inner surface of the hole 6, but the perforated plating layer 9 may be filled in the entire inside of the hole 6.

The conductor layer 8 and the perforated plating layer 9 can be produced by a known method such as an additive method.

Preferably, the conductor layer 8 is first produced, and then the cured film 11 is subjected to heat treatment. In this case, the adhesion between the interlayer insulating layer 7 and the conductor layer 8 formed of the cured film 11 can be further improved. The conditions of the heat treatment are, for example, the heating temperature in the range of 120°C or more and 200°C or less, and the heating time in the range of 30 minutes or more and 120 minutes or less.

The conductor layer 8 can also be produced by sequentially performing electroless plating treatment and electroplating treatment on the cured film 11. At this time, it is preferable to perform heating treatment between the electroless plating treatment and the electroplating treatment, and further perform the heating treatment after the electroplating treatment. At this time, the adhesion between the interlayer insulating layer 7 and the conductor layer 8 formed by the cured film 11 can also be further improved.

From after the production of the cured film 11 to the production of the conductor layer 8, it is preferable not to heat the cured film 11 or heat the cured film 11 to satisfy one or both of the following conditions: the heating temperature is 200 The temperature is below and the heating time is below 150 minutes. That is, from the time after the cured film 11 is produced until the conductor layer 8 is produced, it is preferable not to apply heat treatment to the cured film 11. Even in the case of heat treatment, the conditions are preferably to satisfy one of the following conditions One or both: the heating temperature is 200°C or less, and the heating time is 150 minutes or less. The heating temperature is more preferably 180°C or lower, still more preferably 160°C or lower, and particularly preferably 140°C or lower. The heating time is more preferably 120 minutes or less, still more preferably 90 minutes or less, and particularly preferably 60 minutes or less.

In addition, the heat treatment is preferably carried out in a manner in which the reaction rate of the epoxy group based on the film 4 in the cured film 11 after the heat treatment is lower than 95%. The reaction rate of this epoxy group is based on the amount of epoxy groups in the film 4 before exposure. The heat treatment is more preferably carried out so that the reaction rate of the epoxy group is less than 90%, and even more preferably is carried out so that the reaction rate of the epoxy group is less than 85%, and it is particularly preferable to make the epoxy group The response rate is lower than 80%. Furthermore, the reaction of epoxy groups, based on the IR spectrum of 910 cm ^- calculating the peak intensity derived from ^an epoxy group, which is an IR spectrum of a cured film by the film 4 and the heat treatment implement 11 Obtained by infrared spectrum analysis. In detail, the reaction of epoxy groups, based on 910cm film 4 by the infrared spectroscopic analysis of the obtained IR spectrum ^- normalized value of the peak area at ¹ (S _0), and processed by heat hardening after 910cm IR spectrum of the infrared spectroscopic analysis of the film 11 obtained in the ^- area of the peak at ^a normalized value (S _2), and is calculated using the following _{formula: (S 0 -S 2) ÷} S 0 × 100 (% ). In addition, the normalized value (S ₀ ) and the normalized value (S ₂ ) are relative values based on the area of the following peaks in the IR spectrum: peaks that do not change even if the film 4 is exposed to light. For example 750cm ^- peak at ^1. I.e., normalized value (S _0), IR spectra obtained in 910cm 4 by the infrared spectroscopic analysis of the film ^- measured value of a peak area of ^a (P _0), and 750cm ^- peak area at ¹ The actual measured value (R ₀ ) has a relationship of _{S 0} =P ₀ /R _0. Further, normalized value (S _2), 910cm IR spectrum obtained by the infrared spectroscopic analysis of cured film 11 ^- of the peak area found at ¹ (P _2), and 750cm ^{- a} peak areas of The actual measured value (R ₂ ) has a relationship of _{S 2} =P ₂ /R _2.

In this case, the adhesion between the interlayer insulating layer 7 and the conductor layer 8 can be particularly improved. Although the reason is not yet fully understood, it is presumed that if the heat treatment is not performed, and the conditions are still within the above range even when the heat treatment is performed, there will be a greater amount of presence on the surface of the cured film 11 than in the case of not using this method. There are many functional groups derived from components in the photosensitive resin composition, and the interaction between this functional group and the conductor layer 8 contributes to the improvement of adhesion.

After the cured film 11 is produced until the conductor layer 8 is produced, it is preferable that the cured film 11 is not treated with an oxidizing agent. At this time, it is possible to prevent the cured film 11 from becoming rough due to the oxidizing agent, and it becomes easy to achieve that the arithmetic mean roughness Ra of the cured film 11 is less than 150 nm. It is preferable to use a treatment to the extent that even when the treatment with an oxidizing agent is performed, the arithmetic average roughness Ra of the cured film 11 can be less than 150 nm.

Furthermore, when the hole 6 is provided in the cured film 11, the cured film 11 is subjected to desmear treatment using an oxidizing agent before the conductor layer 8 is produced. The removal of smear in the hole 6 is useful. However, in this embodiment, the photosensitive resin composition can have excellent developability and resolution. Therefore, even if the hole 6 is provided in the cured film 11, it is difficult to leave scum. Therefore, even when the treatment with an oxidizing agent is not performed or when a slight treatment with an oxidizing agent is performed, it is not easy to cause problems caused by scum.

Based on the above, it is possible to produce a multilayer printed wiring board 20 that includes the interlayer insulating layer 7 composed of the cured film 11 and the conductor layer 8 which is in contact with the interlayer insulating layer 7. The thickness of the interlayer insulating layer 7 is, for example, in the range of 3 μm or more and 50 μm or less. In this multilayer printed wiring board 20, as described above, even if the interlayer insulating layer 7 is not roughened or the degree of roughening is small, high adhesion between the interlayer insulating layer 7 and the conductor layer 8 can still be achieved. [Example]

Hereinafter, specific examples of the present invention will be described. Furthermore, the present invention is not limited to the following examples.

[Examples, Comparative Examples and Reference Examples] (1) Synthesis of carboxyl group-containing resin [Synthesis Example A-1] In a four-necked flask equipped with a reflux cooler, thermometer, air blowing tube and agitator, 250 parts by mass It is represented by formula (2) and R ¹ to R ⁷ in formula (2) are all hydrogen bisphenol phenolic epoxy resin (epoxy equivalent 250g/eq), 60 parts by mass of propylene glycol monomethyl ether acetic acid Ester, 140 parts by mass of diethylene glycol monoethyl ether acetate, 0.2 parts by mass of methylhydroquinone, 72 parts by mass of acrylic acid, and 1.5 parts by mass of triphenylphosphine to prepare a mixture. In the flask, the mixture was heated at 115°C for 12 hours while stirring the mixture while the air was bubbling. In this way, a solution of the intermediate is prepared.

Then, 58.8 parts by mass of 3,3',4,4'-biphenyltetracarboxylic dianhydride, 60.8 parts by mass of tetrahydrophthalic anhydride, and 38.7 parts by mass were put into the solution of the intermediate in the flask The propylene glycol monomethyl ether acetate was heated at 115°C for 6 hours while stirring the solution while the air was bubbling, and then at 80°C for 1 hour. Thereby, a 65% by mass solution of carboxyl group-containing resin A-1 was obtained. The weight average molecular weight of the carboxyl group-containing resin A-1 is 3096, and the acid value is 105 mgKOH/g.

[Synthesis Example A-2] The carboxyl group-containing resin having an aromatic ring of Synthesis Example A-2 was prepared in the following manner. In a four-necked flask equipped with a reflux cooler, a thermometer, an air blowing tube, and a stirrer, 288 parts by mass of biphenol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product model NC-3000-H, The epoxy equivalent is 288g/eq), 155 parts by mass of diethylene glycol monoethyl ether acetate, 0.2 parts by mass of methylhydroquinone, 72 parts by mass of acrylic acid, and 3 parts by mass of triphenylphosphine, To prepare the mixture. In the flask, the mixture was heated at 115°C for 12 hours while stirring the mixture while the air was bubbling. In this way, a solution of the intermediate is prepared.

Then, 91.2 parts by mass of tetrahydrophthalic anhydride and 90 parts by mass of diethylene glycol monoethyl ether acetate were put into the solution of the intermediate in the flask, and the air was bubbled. The solution was stirred while heating at 90°C for 4 hours. Thereby, a 65% by mass solution of carboxyl group-containing resin A-2 was obtained. The weight average molecular weight of the carboxyl group-containing resin A-2 is 8120, and the acid value is 76 mgKOH/g.

(2) Preparation of photosensitive resin composition (composition examples 1-9) In a flask, the ingredients shown in Table 1 were blended, and stirred and mixed at a temperature of 35°C for 2 hours to obtain composition example 1 ~9 photosensitive resin composition (refer to Table 1). The photosensitive resin compositions of Composition Examples 1 to 9 were filtered with a 300-mesh filter, and then further filtered with a filter with a pore diameter of 10 μm. The particle size of the organic filler contained in the photosensitive resin composition of Composition Examples 1 to 9 was confirmed using a laser diffraction scattering particle size distribution measuring device, and the maximum particle size was all 10 μm or less.

In addition, the blending amount in Table 1 indicates parts by mass of the solid content of the components described in the table. Moreover, although it is not described in the table, methyl ethyl ketone as a diluent is blended in the photosensitive resin composition.

The details of the components shown in Table 1 are as follows.・Organic filler A with polar groups (dispersion): A dispersion of methyl ethyl ketone with an average primary particle size of 0.07μm and a cross-linked rubber (NBR) with a carboxyl group at a ratio of 15% by weight, JSR Limited Manufactured by the company, the product model is XER-91-MEK, and the acid value is 10.0mgKOH/g.・Organic filler B with polar groups (dispersion): A dispersion of methyl ethyl ketone containing a cross-linked rubber (SBR) with carboxyl and hydroxyl groups at a concentration of 15% by weight and an average primary particle size of 0.07μm , Manufactured by JSR Co., Ltd., product model XSK-500.・Organic filler C (dispersion) with polar groups: manufactured by Nissan Chemical Industry Co., Ltd. The dispersion varnish of fine powder melamine is prepared by dispersing 1.5 parts by mass of melamine fine powder in 3.5 parts by mass of tricyclodecane dimethanol diacrylate using a bead mill. The maximum particle size of fine powder melamine is 5 μm or less.・Organic fillers without polar groups (dispersions): Dispersion varnish of glycidyl modified acrylonitrile butadiene rubber, using a bead mill to make 1.5 parts by mass of powder with an average primary particle size of 0.3μm Glycidyl-modified acrylonitrile butadiene rubber is prepared by dispersing 2.5 parts by mass of tricyclodecane dimethanol diacrylate.・Coupling agent: 3-glycidoxypropyltrimethoxysilane.・Silicon dioxide: manufactured by Nissan Chemical Industry Co., Ltd., product model MEK-EC-2130Y, methyl ethyl ketone dispersed silica sol, grade with improved compatibility with epoxy resin, solid content concentration of 30% by mass , The average primary particle size is 10nm or more and 15nm or less.・Unsaturated compound A: tricyclodecane dimethanol diacrylate (including tricyclodecane dimethanol diacrylate in a dispersion liquid derived from an organic filler).・Unsaturated compound B: Trimethylolpropane triacrylate.・Unsaturated compound C: A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd., product model KAYARAD DPHA.・Photopolymerization initiator A: 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, manufactured by BASF, product model Irgacure TPO.・Photopolymerization initiator B: 1-hydroxy-cyclohexyl-phenyl-ketone, manufactured by BASF, product model Irgacure 184.・Photopolymerization initiator C: 4,4'-bis(diethylamino)diphenyl ketone.・Epoxy compound: Biphenyl type crystalline epoxy resin, manufactured by Mitsubishi Chemical Co., Ltd., product model YX4000, epoxy equivalent of 186g/eq.・Antioxidant: hindered phenolic antioxidant, manufactured by BASF, product model IRGANOX 1010.・Surface conditioner: manufactured by DIC Co., Ltd., product model MEGAFACE F-477.

[Table 1]

(3) Preparation of test pieces (Examples 1-29, Comparative Examples 1-27, Reference Examples 1-18) Using the photosensitive resin compositions of Composition Examples 1-9, test pieces were prepared as follows. The outline of each Example, Comparative Example, and Reference Example is shown in Tables 2-10.

(3-1) Preparation of cured film: First, the photosensitive resin composition of composition examples 1 to 9 was coated on a polyethylene terephthalate film with an applicator, and then the film was made by 95 Heating was performed at °C for 25 minutes to dry, thereby forming a dry film with a thickness of 30 μm on the thin film.

Prepare a glass epoxy copper clad laminate (FR-4 type) with a copper foil with a thickness of 17.5 μm. On this glass epoxy copper clad laminate, comb-shaped electrodes as conductor lines were formed by a subtractive method to obtain a printed wiring board. The line width/spacing of the comb-shaped electrodes was 50 μm/50 μm.

Use an etchant (organic acid micro-etchant manufactured by MEC Co., Ltd., product model CZ-8101) to dissolve and remove the surface layer of the conductor line of the printed circuit board with a thickness of about 1 μm, thereby roughening the conductor line .

A vacuum laminator is used to heat and laminate the dry film on the entire surface of one side of the printed wiring board. The conditions for heating and lamination are 0.5 MPa, 80°C, and 1 minute. In this way, a film composed of a dry film and having a film thickness of 30 μm was formed on the printed wiring board so as to cover the conductor line.

Perform infrared spectrum analysis of this film to obtain IR spectrum.

Next, from the polyethylene terephthalate film, with the negative mask in direct contact with the film, the film was irradiated with ultraviolet ^{light at 300 mJ/cm 2 through the negative mask, thereby} The exposed part of the film is cured to produce a cured film. The negative mask has circular shielding parts with diameters of 30 μm, 45 μm, and 60 μm, and striped shielding parts with a line width/pitch of 40 μm/40 μm. The self-curing film peels off the polyethylene terephthalate film.

Then, in each of the Examples and Reference Examples 1 to 9, the cured film was treated with an alkaline solution, and the unexposed portion of the film was removed with this alkaline solution. When performing the treatment, a 30°C 1% sodium carbonate (Na ₂ CO ₃ ) aqueous solution (pH 11) was sprayed on the cured film at a spray pressure of 0.2 MPa for 90 seconds. Then, pure water was sprayed on the cured film at a spray pressure of 0.2 MPa for 90 seconds to perform cleaning. In this way, an opening is formed where the unexposed part of the cured film is removed. On the other hand, in each of Comparative Examples and Reference Examples 10 to 18, the cured film was not treated with an alkaline solution.

(3-2) Heat treatment of cured film In each of Examples 1-27, each comparative example, and each reference example, the cured film was heated at 150°C for 50 minutes. In Example 28, the cured film was heated at 160°C for 120 minutes. In Example 29, the cured film was heated at 180°C for 120 minutes.

Then, infrared spectroscopy of the cured film is performed to obtain an IR spectrum.

The IR spectrum of the film in 910cm ^- standardized value of the area of the peak at ¹ (S _0), and IR spectrum of the cured film 11 of 910cm ^- the area of the peak at ^a normalized value (S _2), and using The following formula is used to calculate the reaction rate (percentage) of epoxy groups: (S ₀ -S ₂ )÷S ₀ ×100 (%). Further, normalized value (S _0), the IR spectrum of the film is based on the 910 cm ^- the measured values of the peak area at ¹ (P _0), and 750cm ^- Found (R ₀₎ of the peak area at ¹ and the use of S ₀ = P ₀ / R ₀ is calculated from the equation obtained value; normalized value (S _2), according to the IR spectrum of the cured film 910cm ^- Found area of the peak at ¹ (P _2), and 750cm ^- Found (R & lt _2), using equation S ₂ = P ₂ / R ₂ of the area of the peak at ^a calculated value obtained. In addition, the calculation result of the reaction rate of the epoxy group is rounded to the first decimal place.

Based on this result, the reaction rate of epoxy groups is classified in the following manner. A: The reaction rate of epoxy groups is less than 85%. B: The reaction rate of epoxy groups is 85% or more but less than 90%. C: The reaction rate of epoxy groups is 90% or more but less than 95%. D: The reaction rate of the epoxy group is 95% or more.

Then, in each example, each comparative example, and each reference example, a high-pressure mercury lamp was used to irradiate the cured film with ultraviolet rays of ^{1000 mJ/cm 2.}

(3-3) Surface treatment of cured film (3-3-1) In the cases of Examples 1-9, 28-29 and Comparative Examples 1-9 (no roughening) The cured film was cleaned by the following method deal with. Immerse the cured film in a cleaning solution (manufactured by Ato Technology Co., Ltd., Japan, containing 40ml/L Cleaner Securiganth 902, 3ml/L Cleaner Additive 902, 20g/L NaOH) 5 minute. Then, the cured film was first immersed in _{an aqueous solution with a concentration of SnCl 2} of 0.1 g/L for 3 minutes, and then washed with water. Next, the cured film was first immersed in a solution containing 100 g/L sodium persulfate and 10 ml/L sulfuric acid at 25°C for 1 minute, and then washed with water.

(3-3-2) In the case of Examples 10-18 and Comparative Examples 10-18 (low degree of roughening), the cured film was first immersed in a swelling liquid for desmearing residue at 50°C (Japan Ato Technology Co., Ltd. It is manufactured by the company and contains Swelling Dip Securiganth P at a concentration of 500 mL/L and NaOH at a concentration of 3 g/L for 15 minutes to swell, and then wash the cured film with hot water. Then, first immerse the hardened film in a desmear liquid containing potassium permanganate at 50°C (manufactured by Ato Technology Co., Ltd., which contains Concentrate Compact CP with a concentration of 580mL/L and NaOH with a concentration of 40g/L). (Liquid) for 10 minutes to roughen the surface of the cured film, and then wash with hot water. Then, first immerse the cured film in a 40°C neutralization solution (manufactured by Ato Technology Co., Ltd., containing 70mL/L of Reduction solution Securiganth P500, 50mL/L of sulfuric acid (98%)) Remove the residue of the desmear liquid on the surface of the cured film for 5 minutes, and then rinse with water. Then, the cured film is cleaned by the same method as in the case of (4-1) above.

(3-3-3) In the case of Examples 19-27 and Comparative Examples 19-27 (moderate roughening), the surface of the cured film was first immersed in a swelling liquid for desmearing at 80°C (Nippon Atotech Co., Ltd., containing Swelling Dip Securiganth P at a concentration of 500 mL/L and NaOH at a concentration of 3 g/L for 5 minutes to swell, and then wash the cured film with hot water. Then, first immerse the hardened film in a desmear liquid containing potassium permanganate at 60°C (manufactured by Ato Technology Co., Ltd., which contains Concentrate Compact CP with a concentration of 580mL/L and NaOH with a concentration of 40g/L. (Liquid) for 5 minutes to roughen the surface of the cured film, and then wash with hot water. Then, first immerse the cured film in a 40°C neutralization solution (manufactured by Ato Technology Co., Ltd., containing 70mL/L of Reduction solution Securiganth P500, 50mL/L of sulfuric acid (98%)) Remove the residue of the desmear liquid on the surface of the cured film for 5 minutes, and then rinse with water. Then, the cured film is cleaned by the same method as in the case of (4-1) above.

(3-3-4) In the case of Reference Examples 1-18 (highly roughened), the surface of the cured film was first immersed in a swelling solution for desmearing at 70°C (manufactured by Ato Technology Co., Ltd., containing 500 mL /L concentration of Swelling Dip Securiganth P, 3g/L concentration of NaOH solution) for 7.5 minutes to swell, and then the cured film is washed with hot water. Then, first immerse the cured film in a desmear liquid containing potassium permanganate at 70°C (manufactured by Ato Technology Co., Ltd., which contains Concentrate Compact CP with a concentration of 580mL/L and NaOH with a concentration of 40g/L). (Liquid) for 7.5 minutes to roughen the surface of the cured film, and then wash with hot water. Then, first immerse the cured film in a 40°C neutralization solution (manufactured by Ato Technology Co., Ltd., containing 70mL/L of Reduction solution Securiganth P500, 50mL/L of sulfuric acid (98%)) Remove the residue of the desmear liquid on the surface of the cured film for 5 minutes, and then rinse with water. Then, the cured film is cleaned by the same method as in the case of (4-1) above.

The surface roughness (arithmetic mean roughness (Ra)) of the cured film of the test piece after the surface treatment was measured with a laser microscope. Use the following methods to classify the results. The results are shown in the table below. A: The arithmetic average roughness (Ra) is less than 30 nm. B: The arithmetic average roughness (Ra) is 30 nm or more but less than 80 nm. C: The arithmetic average roughness (Ra) is 80 nm or more but less than 150 nm. D: The arithmetic mean roughness (Ra) is 150 nm or more.

(4) Evaluation test The following tests were carried out for the test pieces of the respective examples, comparative examples, and reference examples. The results are shown in Tables 2-10.

(4-1) Adhesion of copper plating: First, apply electroless copper treatment to the hardened film (MV-Plus treatment of Ato Technology Co., Ltd.), then heat it at 150°C for 1 hour, and then heat it at 2A/dm ^{The copper electroplating process was performed at a current density of 2} to form a copper film with a thickness of 33 μm, and then the test piece was heated at 180° C. for 30 minutes. Thereby, a copper plating layer is formed on the cured film. Except for the case where blisters are generated during at least one of the heating after the electroless copper plating process and the heating after the copper electroplating process, the rest is measured in accordance with JIS C6481 for the peel strength of the cured film to peel the copper plating layer. Based on this result, the adhesion of the copper plating layer was evaluated in the following manner. A: The peel strength of the copper plating layer is 0.2 kN/m or more. B: The peel strength of the copper plating layer is 0.1 kN/m or more but less than 0.2 kN/m. C: The peel strength of the copper plating layer is less than 0.1 kN/m. D: Air bubbles are generated in at least one of the heating after the electroless copper plating process and the heating after the copper electroplating process.

(4-2) Electrical insulation. After heating the test piece at 150°C for 1 hour, and further heating it at 180°C for 30 minutes, apply a direct current (DC) 30V between the comb-shaped electrodes in the conductor line of the test piece. Bias voltage, while exposing the test piece to a test environment of 130°C and 85% relative humidity (RH) for 100 hours. In this test environment, the resistance value of the cured film between the comb-shaped electrodes was continuously measured, and the result was evaluated in the following manner. A: From the beginning of the test to 100 hours, the resistance value has been maintained at 10 ⁶ Ω or more. ^{B: The resistance value has been maintained at 10 6} Ω or more from the start of the test to the elapse of 85 hours ^{, but the resistance value has been less than 10 6} Ω from the start of the test to 100 hours before the elapse of time. ^{C: The resistance value has been maintained at 10 6} Ω or more from the start of the test to the lapse of 70 hours ^{, but the resistance value has been less than 10 6} Ω from the start of the test to 85 hours before the lapse. ^{D: The resistance value was less than 10 6} Ω from the start of the test to 70 hours before.

(4-3) Aperture Observe the circular opening of the cured film of the test piece of each of the Examples, Comparative Examples and Reference Examples, and evaluate the results in the following manner. The opening corresponds to the circle of the negative mask. Shaped shielding part. A: The openings corresponding to the shielding portions with diameters of 30 μm, 45 μm, and 60 μm are all formed. B: The opening corresponding to the shielding part with a diameter of 30 μm is not formed, but there are openings corresponding to the shielding part with a diameter of 45 μm and 60 μm. C: The openings corresponding to the shielding parts with diameters of 30 μm and 45 μm are not formed, but the openings corresponding to the shielding parts with the diameter of 60 μm are formed. D: None of the openings corresponding to the shielding portions with diameters of 30 μm, 45 μm, and 60 μm are formed.

(4-4) Resolution Observe the striped openings of the cured film in the test pieces of the respective Examples, Comparative Examples and Reference Examples, and evaluate the results in the following manner. The opening corresponds to the striped shielding portion . A: There is no unevenness in the outline of the opening, and a clear and sharp resolution is displayed. B: Some irregularities are observed in the outline of the opening, but clear resolution is displayed. C: The unevenness of the contour of the opening is observed, and the resolution is slightly poor. D: The unevenness of the outline of the opening is large, and the resolution is poor.

[Table 2]

[table 3]

[Table 4]

[table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9]

[Table 10]

As can be seen from the above-mentioned embodiments, the manufacturing method of the multilayer printed wiring board (20) of the first aspect of the present invention is to produce the film (4) from the photosensitive resin composition on the printed wiring board (1). The photosensitive resin composition contains: a carboxyl group-containing resin (A), an unsaturated compound having at least one ethylenically unsaturated bond in one molecule (B), a photopolymerization initiator (C), and an epoxy compound (D) . By photocuring the film (4), a cured film (11) is produced. The cured film (11) is first treated with an alkaline solution, and then a conductor layer (8) in contact with the cured film (11) is formed. Immediately before the production of the conductor layer (8), the arithmetic average roughness Ra specified by JIS B0601-2001 of the surface of the cured film (11) that is in contact with the conductor layer (8) is less than 150 nm.

According to the first aspect, it is possible to obtain a multilayer printed wiring board (20), which can achieve interlayer insulation even if the interlayer insulation layer (7) composed of the cured film (11) is not roughened or the degree of roughening is small. High adhesion between layer (7) and conductor layer (8).

In the method for manufacturing a multilayer printed wiring board (20) of the second aspect of the present invention, in the first aspect, the arithmetic average roughness Ra is less than 80 nm.

According to the second aspect, the multilayer printed wiring board (20) can have good high-frequency characteristics.

The third aspect of the manufacturing method of the multilayer printed wiring board (20) of the present invention is that in the first or second aspect, from the production of the cured film (11) to the production of the conductor layer (8), it is not correct The cured film (11) is heated, or the cured film (11) is heated so that the reaction rate of the epoxy group based on the film (4) is less than 95%.

According to the third aspect, the adhesion between the interlayer insulating layer (7) formed by the cured film (11) and the conductor layer (8) can be improved.

In the manufacturing method of the multilayer printed wiring board (20) of the fourth aspect of the present invention, in any one of the first to third aspects, the photosensitive resin composition is a dry film.

According to the fourth aspect, it is possible to obtain a multilayer printed wiring board (20) that can achieve interlayer insulation even if the interlayer insulation layer (7) composed of the cured film (11) is not roughened or the degree of roughening is small High adhesion between layer (7) and conductor layer (8).

In the manufacturing method of the multilayer printed wiring board (20) of the fifth aspect of the present invention, in any one of the first to fourth aspects, the photosensitive resin composition further contains an organic filler (E).

According to the fifth aspect, the adhesion between the interlayer insulating layer (7) formed by the cured film (11) and the conductor layer (8) can be improved.

In the sixth aspect of the manufacturing method of the multilayer printed wiring board (20) of the present invention, in the fifth aspect, the organic filler (E) has a polar group.

According to the sixth aspect, the adhesion between the interlayer insulating layer (7) formed by the cured film (11) and the conductor layer (8) can be further improved.

In the seventh aspect of the manufacturing method of the multilayer printed wiring board (20) of the present invention, in the sixth aspect, the polar group includes at least one group selected from the group consisting of a carboxyl group, an amino group, and a hydroxyl group.

According to the seventh aspect, the adhesion between the interlayer insulating layer (7) formed by the cured film (11) and the conductor layer (8) can be particularly improved.

The manufacturing method of the multilayer printed wiring board (20) of the eighth aspect of the present invention is that in any one of the fifth to seventh aspects, the organic filler (E) is the particles in the photosensitive resin composition The diameter is 10 μm or less. The adhesion between the interlayer insulating layer (7) and the conductor layer (8) formed by the cured film (11) can be particularly improved.

According to the eighth aspect, the adhesion between the interlayer insulating layer (7) formed by the cured film (11) and the conductor layer (8) can be particularly improved.

The ninth aspect of the manufacturing method of the multilayer printed wiring board (20) of the present invention is that in any one of the first to eighth aspects, from the production of the cured film (11) to the production of the conductor layer (11) Before ), the cured film (11) was not treated with an oxidizing agent.

According to the ninth aspect, it is possible to prevent the cured film (11) from becoming rough due to the oxidizing agent, and it becomes easy to achieve that the arithmetic mean roughness Ra of the cured film (11) is less than 150 nm.

The multilayer printed wiring board (20) of the tenth aspect of the present invention is manufactured by any one of the first to ninth aspects of the manufacturing method.

According to the tenth aspect, a multilayer printed wiring board (20) can be obtained, which has high adhesion between the interlayer insulating layer (7) and the conductor layer (8).

1‧‧‧Printed circuit board 2‧‧‧Insulation layer 3‧‧‧Conductor circuit 4‧‧‧Film 5‧‧‧Unexposed part 6‧‧‧Hole 7‧‧‧Interlayer insulating layer 8‧‧‧Conductor layer 9 ‧‧‧Perforated plating 10‧‧‧Through hole 11‧‧‧Cured film 20‧‧‧Multilayer printed circuit board

Fig. 1A to Fig. 1E are cross-sectional views showing steps of manufacturing a multilayer printed wiring board.

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1‧‧‧Printed circuit board

2‧‧‧Insulation layer

3‧‧‧Conductor line

4‧‧‧Coating

5‧‧‧Unexposed part

6‧‧‧Hole

7‧‧‧Interlayer insulation

8‧‧‧Conductor layer

9‧‧‧Perforated Plating

10‧‧‧Through hole

11‧‧‧hardened film

20‧‧‧Multilayer printed circuit board

Claims (9)

A method for manufacturing a multilayer printed wiring board, wherein a film is made of a photosensitive resin composition on the printed wiring board; the photosensitive resin composition contains: a carboxyl group-containing resin (A), and one molecule has at least one ethylenic unsaturation Bond unsaturated compound (B), photopolymerization initiator (C), and epoxy compound (D); the solid content of the carboxyl-containing resin (A) has an acid value in the range of 40 mgKOH/g or more and 160 mgKOH/g or less Inside; and then by photocuring the aforementioned film to produce a cured film; then, the aforementioned cured film is treated with an alkaline solution, and then a conductor layer in contact with the aforementioned cured film is produced; from the production of the aforementioned cured film until the aforementioned Between the conductive layer and the conductive layer, the cured film is heated so that the reaction rate of the epoxy group based on the film is less than 95%; and immediately before the conductive layer is produced, the and the cured film The arithmetic average roughness Ra specified by the Japanese Industrial Standard B0601-2001 of the contact surface of the aforementioned conductor layer is less than 150 nm. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein the arithmetic average roughness Ra is less than 80 nm. The method for manufacturing a multilayer printed wiring board according to claim 1 or 2, wherein the photosensitive resin composition is a dry film. The method for manufacturing a multilayer printed wiring board according to claim 1 or 2, wherein the photosensitive resin composition further contains an organic filler (E). The method for manufacturing a multilayer printed wiring board according to claim 4, wherein the organic filler (E) has a polar group. The method for manufacturing a multilayer printed wiring board according to claim 5, wherein the polar group includes at least one group selected from the group consisting of a carboxyl group, an amino group, and a hydroxyl group. The method for manufacturing a multilayer printed wiring board according to claim 4, wherein the particle size of the organic filler (E) in the photosensitive resin composition is 10 μm or less. The method of manufacturing a multilayer printed wiring board according to claim 1 or 2, wherein the cured film is not treated with an oxidizing agent from after the cured film is produced until the conductor layer is produced. A multilayer printed circuit board is manufactured by the method for manufacturing a multilayer printed circuit board according to any one of claims 1 to 8.

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