TWI809215B - Resin composition for forming insulation film, manufucturing method of resin composition for forming insulation film, dry film, printed circuit board, and manufacturing method of printed circuit board - Google Patents

Abstract

An object of the present invention is to provide a resin composition having a stable viscosity, a coating film having high uniformity in film thickness and high rheology, and capable of forming an insulating film having excellent insulation reliability. A resin composition for forming an insulating film containing a curable resin (A), bentonite (E), a first solvent (F1), and a second solvent (F2). The solubility of the first solvent (F1) in 1 liter of water at 20° C. is 1 g or more, and the solubility of the second solvent (F2) in 1 liter of water at 20° C. is less than 1 g. The total amount of the first solvent (F1) and the second solvent (F2) is 15% by mass or more and 50% by mass or less with respect to the total amount of the resin composition. The quantity of the 2nd solvent (F2) is 15 mass % or more and 50 mass % or less with respect to the total quantity of the 1st solvent (F1) and the 2nd solvent (F2).

Description

Resin composition for forming insulating film, method for producing resin composition for forming insulating film, dry film, printed wiring board, and method for producing printed wiring board

The present invention relates to the following technologies: a resin composition for forming an insulating film; a method for manufacturing the resin composition for forming an insulating film; a dry film; a printed wiring board; and, a method for manufacturing a printed wiring board. Specifically, the present invention relates to the following technologies: a resin composition used to form an insulating film in a printed wiring board; a dry film formed from the resin composition; a resin composition and, a printed wiring board and a manufacturing method thereof, wherein the printed wiring board is provided with an insulating film, and the insulating film is formed of the resin composition.

In order to form a solder resist layer in a printed wiring board, various photosensitive resin compositions have been used. The solder resist layer is formed by irradiating the coating film of the photosensitive resin composition with ultraviolet rays (hereinafter also referred to as UV) or the like to harden it.

For example, in Patent Document 1 (Japanese Unexamined Patent Publication No. 2018-53215), a photocurable thermosetting resin composition is disclosed as a photosensitive resin composition for forming a cured film of a printed wiring board or the like. The curable thermosetting resin composition is composed of the following components: carboxyl group-containing resin, photopolymerization initiator, dye, reactive diluent, and thermosetting component. This resin composition can be used as a cured film of a printed wiring board or the like after being applied on a base material and cured. Also disclosed is a technique for preparing a rheological agent in order to impart rheology (thixotropy) to an uncured coating film made of a composition.

The rheological agent is used as needed for, for example, uniformizing the film thickness of the coating film formed from the composition or suppressing sagging of the coating film.

However, the rheological agent tends to increase the viscosity of the composition, so that the film-forming property of the composition may deteriorate, or conversely, the uniformity of the film thickness of the coating film formed from the composition may decrease. In addition, the rheological agent may lower the insulation reliability of the insulating film.

The object of the present invention is to provide the following technology: a resin composition, which is less prone to increase in viscosity due to rheological agents, and can make the insulation reliability of the insulating film less likely to decrease; a dry film, which is the resin composition. a dry product; and, a method for producing a resin composition for forming an insulating film.

Another object of the present invention is to provide the following technology: a printed wiring board including an interlayer insulating film formed of the above-mentioned resin composition for forming an insulating film; a printed wiring board including a resistive film. A solder layer, the solder resist layer is formed of the above-mentioned resin composition; and, a method for manufacturing the printed circuit boards.

The resin composition for insulating film formation in one Embodiment of this invention contains curable resin (A), bentonite (E), a 1st solvent (F1), and a 2nd solvent (F2). The solubility of the first solvent (F1) in 1 liter of water at 20° C. is 1 g or more. The solubility of the second solvent (F2) in 1 liter of water at 20° C. is less than 1 g. The total amount of the first solvent (F1) and the second solvent (F2) is 15% by mass or more and 50% by mass or less with respect to the total amount of the resin composition. The quantity of the said 2nd solvent (F2) is 15 mass % or more and 50 mass % or less with respect to the total amount of the said 1st solvent (F1) and the 2nd solvent (F2).

A method for producing a resin composition for forming an insulating film according to an embodiment of the present invention includes a step of producing a carboxyl group-containing resin (A1-1) in the presence of the first solvent (F1), the novolac In a solution of the epoxy resin (a1) having the structure and the aforementioned monocarboxylic acid (b1), the epoxy resin (a1) having the novolac structure is reacted with the aforementioned monocarboxylic acid (b1) to synthesize an intermediate, and then the aforementioned The polycarboxylic acid (b2) is added to the aforementioned solution to react the aforementioned intermediate with the aforementioned polycarboxylic acid (b2), and during the reaction of the aforementioned intermediate with the aforementioned polycarboxylic acid (b2), the aforementioned second solvent ( F2) is added to the aforementioned solution to manufacture a carboxyl group-containing resin (A1-1).

The dry film in one embodiment of the present invention is a dried product of the aforementioned resin composition for insulating film formation.

A printed wiring board according to an embodiment of the present invention includes an insulating film containing a cured product of the resin composition for forming the insulating film.

A method of manufacturing a printed wiring board according to an embodiment of the present invention is a method of manufacturing a printed wiring board including a conductor line and an insulating film overlapping the conductor line; and the production method includes A step of forming the insulating film from the resin composition for forming the insulating film.

Hereinafter, the form for carrying out this invention is demonstrated. In addition, in the following description, "(meth)acryl" means at least one of "acryl" and "methacryl". For example, (meth)acrylate means at least one of acrylate and methacrylate. In addition, in the present embodiment, the term "layer" also includes films such as films and sheets formed in a film shape, such as coating films and coating films.

The resin composition for insulating film formation in this embodiment contains curable resin (A), bentonite (E), first solvent (F1) and second solvent (F2). The solubility of the first solvent (F1) in 1 liter of water at 20° C. is 1 g or more. The solubility of the second solvent (F2) in 1 liter of water at 20° C. is less than 1 g. The total amount of the first solvent (F1) and the second solvent (F2) is 15% by mass or more and 50% by mass or less with respect to the total amount of the resin composition for insulating film formation. The quantity of the 2nd solvent (F2) is 15 mass % or more and 50 mass % or less with respect to the total quantity of the 1st solvent (F1) and the 2nd solvent (F2).

Bentonite (E) is a rheological agent. When the resin composition contains bentonite (E), the rheology of the uncured coating film made of the resin composition can be improved. Thereby, it is possible to make the coating film less prone to sagging. In addition, the bentonite (E) makes it difficult to lower the insulation reliability of the insulating film obtained by curing the coating film, so that the insulation reliability can be improved on the contrary. Furthermore, by containing the first solvent (F1) and the second solvent (F2) in the resin composition at the above-mentioned ratio, the viscosity increase of the resin composition caused by the inclusion of bentonite (E) is less likely to occur, and further, the coating can be made The film thickness of the film is easily uniformized.

Therefore, according to the present embodiment, it is difficult to increase the viscosity of the resin composition due to the rheological agent, and it is difficult to reduce the insulation reliability of the insulating film made of the resin composition.

The reason why the above effect occurs is not clear, but it is considered to be as follows.

The increase in viscosity due to bentonite (E) is thought to be due to the interaction between bentonite (E) and a solvent. The bentonite (E) has a layered crystalline structure, and the solvent is trapped between the layers of the crystalline structure, so it is considered that a large interaction between the bentonite (E) and the solvent is likely to occur, thereby causing the interaction due to the interaction. The resulting viscosity rise. However, it is considered that in the resin composition for forming an insulating film according to the present embodiment, the interaction between the solvent and the bentonite (E) can be adjusted so that the viscosity does not easily increase under the following conditions: The total amount of the first solvent (F1) and the second solvent (F2) is set to 15% by mass or more and 50% by mass or less with respect to the total amount of the entire resin composition, and further the amount of the second solvent (F2) is The amount is 15% by mass or less and 50% by mass or less with respect to the total amount of the first solvent (F1) and the second solvent (F2). That is, it is considered that the interaction between bentonite (E) and the solvent will be affected by the amount of solvent in the composition and the degree of hydrophilicity of the solvent, so by using the amount of the solvent and the degree of hydrophilicity of the solvent, By adjusting the above method, the increase in viscosity due to the interaction becomes less likely to occur.

It is also believed that because bentonite (E) is easy to capture cations between the layers of its crystal structure, the cations are captured in the insulating film and ion migration is difficult to occur, so the insulation reliability of the insulating film can be improved.

Hereinafter, each component contained in the resin composition for insulating film formation (it is also called resin composition (P) hereafter) is demonstrated in detail about this embodiment.

1. Hardening resin (A) The curable resin (A) contains, for example, at least one resin component selected from the group consisting of photocurable resins and thermosetting resins.

A thermosetting resin, for example containing at least one resin selected from the group consisting of the following resins: epoxy resin; polyimide resin; polyamideimide resin; triazine resin; phenol resin; Melamine resins; urea resins; silicone resins; polyester resins; cyanate resins; and resins modified from such resins. In addition, about a thermosetting resin, it demonstrates in detail in "1-3. Thermosetting resin (C)" mentioned later.

The photocurable resin contains, for example, at least one compound selected from the group consisting of a monomer having a polymerizable unsaturated bond in its molecule and a prepolymer.

Curable resin (A) preferably contains photocurable resin. In this case, the curable resin (A) can impart photosensitivity to active energy rays such as ultraviolet rays and electron rays to the resin composition (P).

The photocurable resin preferably contains a carboxyl group-containing resin (A1). At this time, the carboxyl group-containing resin (A1) can provide developability by an alkaline solution to the resin composition (P). Therefore, an insulating film having an appropriate pattern can be produced by photolithography using the resin composition (P).

1-1. Carboxyl-containing resin (A1) The carboxyl group-containing resin (A1) contains at least one carboxyl group in the molecule. The carboxyl group-containing resin (A1) can impart alkali developability to the resin composition (P). The carboxyl group-containing resin (A1), for example, is not particularly limited as long as it is a resin having an ethylenically unsaturated group and a carboxyl group.

The carboxyl group-containing resin (A1), for example, can contain a resin (hereinafter, also referred to as the first resin) having a structure in which at least a part of an epoxy compound is formed by an ethylenically unsaturated compound having a carboxyl group. The epoxy group reacts and further adds a compound selected from the group consisting of at least one selected from polyvalent carboxylic acids and their anhydrides.

The carboxyl group-containing resin (A1) may contain the following resin (hereinafter also referred to as the second resin) obtained by reacting an ethylenically unsaturated compound having an epoxy group with a polymer of an ethylenically unsaturated compound. Obtained, the ethylenically unsaturated compound includes a compound having a carboxyl group.

The carboxyl group-containing resin (A1) may contain the following resin (hereinafter, also referred to as the third resin), which reacts a part of the epoxy groups in the epoxy compound by a monocarboxylic acid, and is selected from It is obtained by reacting another part of epoxy groups with a compound selected from the group consisting of at least one polycarboxylic acid.

The third resin has, in its structure, a secondary hydroxyl group and a carboxyl group located at the end of the side chain in the structure. This is presumed to be the reason why the carboxyl group-containing resin (A1) exhibits excellent developability when an alkaline solution is used as a developing solution. Moreover, when a monocarboxylic acid has an ethylenically unsaturated group, the 3rd resin will have the ethylenically unsaturated group located in the side chain terminal in the structure, and the carboxyl group located in the side chain terminal in the structure. This is presumed to be the reason why the carboxyl group can have high reactivity. Therefore, the interlayer insulating layer and the solder resist layer made of the resin composition (P) can have high electrical insulation reliability.

The ratio of the carboxyl group-containing resin (A1) to the solid content of the resin composition (P), for example, is in the range of 20% by mass to 60% by mass, preferably 25% by mass to 55% by mass within range.

Next, the carboxyl group-containing resin (A1-1) will be described.

The carboxyl group-containing resin (A1), among the above-mentioned third resins, particularly preferably contains a carboxyl group-containing resin (A1-1) having the following addition structure, which is a monocarboxylic acid (b1) Addition-reacts with some epoxy groups of the epoxy resin (a1) which has a novolac structure, and polyvalent carboxylic acid (b2) adds-reacts with another part of epoxy groups. That is, curable resin (A) preferably contains carboxyl group-containing resin (A1-1). In this case, the bentonite (E) can further improve the rheology of the uncured coating film of the resin composition (P). This is considered to be because the carboxyl group-containing resin (A1-1) has a secondary hydroxyl group generated from an epoxy group and a monocarboxylic acid (b1) and a carboxyl group derived from a polycarboxylic acid (b2), and the epoxy group, hydroxyl group And the carboxyl group will interact with the bentonite (E). Thereby, the film thickness stability of the coating film formed from a resin composition (P) can be improved more. Furthermore, the insulating layer formed from the cured product of the resin composition (P) can have further excellent insulating reliability.

The epoxy equivalent of the carboxyl group-containing resin (A1-1) is preferably 6000 g/eq. or more. In this case, it is difficult to gel the carboxyl group-containing resin (A1-1), and thus can contribute to making it difficult to lower the alkali developability of the resin composition (P). The epoxy equivalent of the carboxyl group-containing resin (A1-1) is more preferably at least 8000 g/eq. In this case, the viscosity of the resin composition (P) can be made less prone to excessive thickening, and the rheology of the coating film formed from the resin composition (P) can be maintained favorably. Furthermore, it can contribute to the fact that the insulation reliability of the insulating film containing the hardened|cured material of a resin composition (P) becomes less likely to fall. This is considered to be due to the following reasons: as long as the epoxy equivalent is more than 8000g/eq., most of the epoxy groups in the epoxy resin (a1) will be replaced by side chains with secondary hydroxyl and carboxyl groups. This can increase the interaction between the carboxyl group-containing resin (A1-1), bentonite (E) and water-soluble solvent (F1). The epoxy equivalent of the carboxyl group-containing resin (A1-1) is more preferably at least 8500 g/eq., particularly preferably at least 9000 g/eq. Moreover, the upper limit of the epoxy equivalent of carboxyl group-containing resin (A1-1) is not specifically limited, For example, it is 100000g/eq.

Next, the raw materials of the carboxyl group-containing resin (A1-1) and the reaction conditions for synthesizing the carboxyl group-containing resin (A1-1) will be described in detail.

The epoxy resin (a1) which has a novolac structure has the structure represented by following formula (1), for example. X in formula (1) is a divalent hydrocarbon group, and R is a hydrogen atom or an alkyl group. The epoxy resin (a1), for example, contains at least one of the following cresol novolac epoxy resins (a11), phenol novolak epoxy resins (a12) and biphenyl novolak epoxy resins (a13) .

The cresol novolak type epoxy resin (a11), for example, has a structure in which R and X in formula (1) are each a methyl group and a methylene group.

The phenol novolac epoxy resin (a12) has, for example, a structure in which R and X in the formula (1) are each a hydrogen atom and a methylene group.

Biphenyl novolac type epoxy resin (a13), for example, can have the structure that R and X in formula (1) are hydrogen atom and biphenyl group respectively, also can be that R and X are hydrogen atom and biphenyl group respectively and It has a structure composed of two methylene groups each connected to both ends of the formula (1).

The epoxy resin (a1), more preferably, contains a compound selected from the group consisting of cresol novolac epoxy resin (a11), phenol novolac epoxy resin (a12) and biphenol novolac epoxy resin (a13). At least one component in the group further preferably contains a formaldehyde novolak type epoxy resin (a11). Furthermore, the epoxy resin (a1) is not limited to the resin having the structure shown in the above-mentioned formula (1), for example, it may contain an epoxy resin selected from a novolak type epoxy resin having a cyclopentadiene skeleton and a resin having a naphthalene skeleton. At least one component of the group consisting of novolac epoxy resins.

The monocarboxylic acid (b1) preferably has an ethylenically unsaturated bond. In this case, the carboxyl group-containing resin (A1-1) can have photocurability by having an ethylenically unsaturated bond derived from a monocarboxylic acid (b1). Examples of components contained in the monocarboxylic acid (b1) include compounds having only one ethylenically unsaturated group and compounds having a plurality of ethylenically unsaturated groups. Examples of compounds having only one ethylenically unsaturated group include: acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, 2-acryloxyethyl succinate, 2-methacryloxy succinate Butyl ethyl ester, 2-acryloxyethyl butyrate, 2-methacryloxyethyl butyrate, β-carboxyethyl acrylate, acryloxyethyl succinate, methyl succinate Acryloxyethyl ester, 2-propionic acid, 3-(2-carboxyethoxy)-3-oxypropyl ester, 2-acryloxyethyl tetrahydrophthalate, tetrahydrophthalate 2-Methacryloxyethyl Formate, 2-Acryloxyethyl Hexahydrophthalate, 2-Methacryloxyethyl Hexahydrophthalate and ω-Carboxypolycaprolactone ester monoacrylate. Examples of compounds having a plurality of ethylenically unsaturated groups include compounds obtained by reacting dibasic acid anhydrides with polyfunctional acrylates having hydroxyl groups, and compounds obtained by reacting dibasic acid anhydrides with polyfunctional methacrylates having hydroxyl groups The compound obtained. More specifically, examples of compounds having a plurality of ethylenically unsaturated groups include: pentaerythritol triacrylate, pentaerythritol trimethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate esters, dipentaerythritol pentaacrylate and dipentaerythritol pentamethacrylate. Monocarboxylic acid (b1) can contain 1 type or 2 or more types of these components. The monocarboxylic acid (b1) particularly preferably contains one or more components selected from the group consisting of acrylic acid and methacrylic acid. In this case, the sticking of the wet coating film formed by the resin composition (P) can be sufficiently suppressed, and the plating resistance, soldering heat resistance, and insulation reliability of insulating layers such as interlayer insulating layers and solder resist layers can be improved. sex.

Examples of components contained in the polycarboxylic acid (b2) include: oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, Maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid and tetrahydrophthalic acid, etc. The polyhydric carboxylic acid (b2) can contain 1 type or 2 or more types of these components. The polycarboxylic acid (b2) particularly preferably contains one or more components selected from the group consisting of malonic acid, glutaric acid, maleic acid, tetrahydrophthalic acid, and phthalic acid, and more preferably Preferably tetrahydrophthalic acid is included. In this case, the plating resistance and insulation reliability of the insulating layer can be improved by reducing the water absorption of the interlayer insulating layer and the solder resist layer formed of the resin composition (P).

The carboxyl group-containing resin (A1-1), as described above, is a reactant, which is formed by reacting an epoxy resin (a1) having a novolak structure with a monocarboxylic acid (b1) and a polycarboxylic acid (b2). have to. This carboxyl group-containing resin (A1-1) has an addition structure in which a monocarboxylic acid (b1) is added to some epoxy groups among the plurality of epoxy groups contained in the epoxy resin (a1) , and the polyvalent carboxylic acid (b2) is added to another part of the epoxy groups among the plurality of epoxy groups that the epoxy resin (a1) has.

Carboxyl group-containing resin (A1-1) can be manufactured by the following method, for example.

First, a monocarboxylic acid (b1) is reacted with an epoxy resin (a1). Thereby, as shown in the following formula (2), the monocarboxylic acid (b1) will be added to some epoxy groups among the plurality of epoxy groups of the epoxy resin (a1), and an intermediate (hereinafter , called the first intermediate). Therefore, the first intermediate has a structure represented by the following formula (3) and an unreacted epoxy group. Since the first intermediate has a structure represented by the following formula (3), the first intermediate has a secondary hydroxyl group on the side chain. The addition reaction of the following formula (2) is preferably carried out in a solvent in the presence of a polymerization inhibitor and a catalyst.

X in the above formulas (2) and (3) represents an unsaturated carboxylic acid residue. Also, R in the formulas (2) and (3) is a hydrogen atom or an alkyl group.

Then, the first intermediate is reacted with the polycarboxylic acid (b2), whereby, as shown in the following formula (4), the polycarboxylic acid (b2) is added to the unreacted ring of the first intermediate. On the oxygen group, and generate carboxyl-containing resin (A1-1). Therefore, the carboxyl group-containing resin (A1-1) has a structure represented by the following formula (5). Therefore, the carboxyl group-containing resin (A1-1) has a secondary hydroxyl group on the side chain and a carboxyl group on the terminal of the side chain.

Y in formula (4), (5) represents a polyhydric carboxylic acid residue. Also, R in the formulas (4) and (5) is a hydrogen atom or an alkyl group.

Furthermore, when the first intermediate is reacted with the polycarboxylic acid (b2), the polycarboxylic acid (b2) will preferentially react with the unreacted epoxy group that the intermediate has, rather than the unreacted epoxy group that the intermediate has. secondary hydroxyl. Therefore, the carboxyl group-containing resin (A1-1) has a structure represented by formula (3) and a structure represented by formula (5).

The carboxyl group-containing resin (A1-1) has a secondary hydroxyl group in the structures represented by the above formulas (3) and (5), and a carboxyl group at the end of the side chain in the structure represented by the above formula (5). This is presumed to be the reason why the carboxyl group-containing resin (A1-1) exhibits excellent developability when an alkaline solution is used as a developing solution. Also, the carboxyl group-containing resin (A1-1) has an ethylenically unsaturated group at the end of the side chain in the structure represented by the above formula (3), and an ethylenically unsaturated group at the end of the side chain in the structure represented by the above formula (5). carboxyl group. This is presumed to be the reason why the carboxyl group can have high reactivity. Therefore, insulating films such as interlayer insulating layers and solder resist layers made of the resin composition (P) can have higher electrical insulation reliability.

When synthesizing the carboxyl-containing resin (A1-1), the monocarboxylic acid (b1) and the polycarboxylic acid (b2) can be reacted with the epoxy resin (a1) simultaneously, or the polycarboxylic acid (b2) can be reacted with the polycarboxylic acid (b2) After the epoxy resin (a1) is reacted, it is made to react with the monocarboxylic acid (b1).

Examples of catalysts used in the synthesis of carboxyl-containing resins (A1-1) include: tertiary amines such as triethylamine; quaternary ammonium salts such as triethylbenzyl ammonium chloride; 2-ethyl- Imidazole compounds such as 4-methylimidazole; phosphorus compounds such as triphenylphosphine; and metal salts of organic acids such as lithium, chromium, zirconium, potassium, and sodium, the organic acid being naphthenic acid, lauric acid, stearic acid , oleic acid or octenoic acid. These catalysts may be used alone or in combination of two or more.

Examples of polymerization inhibitors used in the synthesis of carboxyl-containing resin (A1-1) include: hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, and phenothiazine (phenothiazine). These polymerization inhibitors may be used alone or in combination of two or more.

The solvent used for synthesizing the carboxyl group-containing resin (A1-1) is not particularly limited, and may include the first solvent (F1) and the second solvent (F2) described in "4. Solvent" described later. For example, when using the first solvent (F1) and the second solvent (F2) in the case of synthesis, as long as the solvent content in the resin solution of the obtained carboxyl-containing resin (A1-1) is used, and to meet the requirements of this implementation As for the conditions in the composition of the resin composition (P) of the form, the amounts of the first solvent (F1) and the second solvent (F2) may be appropriately adjusted. Specific examples of solvents used in the synthesis of carboxyl-containing resins (A1-1) include: ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; Ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether , propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether and other glycol ethers; ethyl acetate, butyl acetate, ethylene glycol monoethyl ether Acetate, Ethylene Glycol Monobutyl Ether Acetate, Diethylene Glycol Monoethyl Ether Acetate, Diethylene Glycol Monobutyl Ether Acetate, Propylene Glycol Monomethyl Ether Acetate, Dipropylene Glycol Acetate esters such as monomethyl ether acetate; alcohols such as ethanol, propanol, ethylene glycol, and propylene glycol; aliphatic hydrocarbons such as octane and decane; and petroleum ether, naphtha, and hydrogenated naphtha , Solvent naphtha and other petroleum-based solvents. Among these organic solvents, only one of them may be used, or two or more of them may be used in combination. The solvent used when synthesizing the carboxyl-containing resin (A1-1) preferably includes a solvent selected from the group consisting of the above-mentioned aromatic hydrocarbons, petroleum solvents, and diethylene glycol monoethyl ether acetate. at least one.

When epoxy resin (a1-1) is reacted with monocarboxylic acid (b1), the amount of the epoxy group of its monocarboxylic acid (b1) relative to 1mol (mole) of epoxy resin (a1-1), Preferably, it exists in the range of 0.2 mol or more and 0.8 mol or less, More preferably, it exists in the range of 0.3 mol or more and 0.7 mol or less. Also, when the first intermediate is reacted with the polycarboxylic acid (b2), the amount of the epoxy group of the polycarboxylic acid (b2) relative to 1 mol of the epoxy resin (a1-1) is preferably 0.2 mol It exists in the range of 0.8 mol or more, More preferably, it exists in the range of 0.3 mol or more and 0.7 mol or less. That is, with respect to 1 mol of epoxy groups of the epoxy resin (a1-1), it is preferable that the monocarboxylic acid (b1) is in the range of 0.2 mol or more and 0.8 mol or less, and the polycarboxylic acid (b2) is in the range of 0.2 mol or less. mol or more and 0.8 mol or less. Also, with respect to 1 mol of epoxy groups in the epoxy resin (a1-1), it is more preferable that the monocarboxylic acid (b1) is in the range of 0.3 mol or more and 0.7 mol or less, and the polycarboxylic acid (b2) is in the range of 0.3 mol or less. In the range of above and below 0.7 mol. In this case, it is possible to easily combine the characteristics of enhancing the UV sensitivity of the resin composition for insulating film formation and securing alkali developability.

The ratio of the carboxyl group-containing resin (A1-1) to the entire carboxyl group-containing resin (A1) is preferably at least 15% by mass, more preferably at least 25% by mass, further preferably at least 35% by mass, and most preferably at least 45% by mass %above. The upper limit of the ratio of the carboxyl group-containing resin (A1-1) to the entire carboxyl group-containing resin (A1) is not particularly limited, but is, for example, 92% by mass or less, preferably 84% by mass or less.

The weight average molecular weight of the carboxyl group-containing resin (A1) is preferably from 4,000 to 30,000. When the weight average molecular weight is within the above range, insulation reliability and plating resistance can be imparted to a cured product made of the resin composition (P). Moreover, if the weight average molecular weight is in the said range, especially the developability by alkaline aqueous solution of a photosensitive resin composition can be improved. The weight average molecular weight (Mw) of the carboxyl group-containing resin (A1) can be calculated from the molecular weight measurement result by gel permeation chromatography. Molecular weight measurement by gel permeation chromatography can be performed, for example, under the following conditions.

GPC device: SHODEX SYSTEM 11 manufactured by Showa Denko; Column: Four series of SHODEX KF-800P, KF-005, KF-003, KF-001; Mobile phase: tetrahydrofuran (THF); Flow rate: 1mL/min; Column temperature: 45°C; Detector: Refractive Index (RI); Conversion: polystyrene.

1-2. Photopolymerizable compound (B) It is preferable that the resin composition (P) also contains a photopolymerizable compound (B). The photopolymerizable compound (B) can impart photocurability to the resin composition (P). In addition, as mentioned above, a photopolymerizable compound (B) is a component contained in photocurable resin, and is also a component contained in curable resin (A).

The photopolymerizable compound (B) is a compound having at least one ethylenically unsaturated double bond in one molecule. The photopolymerizable compound (B) can contain, for example: at least one compound selected from the group consisting of monofunctional (meth)acrylates and polyfunctional (meth)acrylates, the monofunctional (meth)acrylate The ester is 2-hydroxyethyl (meth)acrylate, etc., and the multifunctional (meth)acrylate is diethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane di(meth)acrylate, Methylolpropane tri(meth)acrylate, Pentaerythritol tri(meth)acrylate, Pentaerythritol tetra(meth)acrylate, Dipentaerythritol penta(meth)acrylate, Dipentaerythritol hexa(meth)acrylate, ε-caprolactone modified dipentaerythritol hexaacrylate, etc.

The photopolymerizable compound (B) may contain a trifunctional compound, that is, a compound having three unsaturated bonds in one molecule. In this case, when the film formed of the resin composition is exposed and developed, its resolution can be improved, and in particular, the developability of the resin composition by an alkaline aqueous solution can be improved. The trifunctional compound can contain at least one selected from the group consisting of the following compounds: trimethylolpropane tri(meth)acrylate, EO modified trimethylolpropane tri(meth)acrylate, Pentaerythritol tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate and ε-caprolactone modified ginseng-(2-propenyloxyethyl)isocyanurate and tri(methyl ) ethoxylated glycidyl acrylate.

The photopolymerizable compound (B) may contain a phosphorus-containing compound (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, for example, can contain at least one selected from the group consisting of the following compounds: 2-methacryloxyethyl acid phosphate (as a specific example, manufactured by Kyoeisha Chemical Co., Ltd. Model LIGHT ESTER P-1M, and LIGHT ESTER P-2M), 2-acryloxyethyl acid phosphate (as a specific example, model LIGHT ACRYLATE P-1A manufactured by Kyoeisha Chemical Co., Ltd.), diphosphate Phenyl-2-methacryloxyethyl ester (as a specific example, model MR-260 manufactured by Daihachi Industry Co., Ltd.), and HFA series manufactured by Showa High Polymer Co., Ltd. (as a specific example, dipentaerythritol Addition reaction products of hexaacrylate and HCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide), namely models HFA-6003 and HFA-6007; caprolactone modification The addition reaction products of dipentaerythritol hexaacrylate and HCA (models HFA-3003 and HFA-6127, etc.).

The photopolymerizable compound (B) may also contain a prepolymer. The prepolymer can include, for example: a prepolymer obtained by adding an ethylenically unsaturated group after polymerizing a monomer having an ethylenically unsaturated bond; At least one prepolymer of the group consisting of prepolymers. Oligomeric (meth)acrylate prepolymers, for example, can contain at least one selected from the group consisting of: epoxy (meth)acrylate, polyester (meth)acrylate, amine Ester (urethane) (meth)acrylate, alkyd (alkyd) resin (meth)acrylate, silicone resin (meth)acrylate, and spirane (spirane) resin (meth)acrylate.

When the curable resin (A) contains a carboxyl group-containing resin (A1) and a photopolymerizable compound (B), the ratio of the photopolymerizable compound (B) to the carboxyl group-containing resin (A1) is preferably 5% by mass or more and 50 mass % or less, more preferably 7 mass % or more and 40 mass % or less, still more preferably 9 mass % or more and 35 mass % or less.

1-3. Thermosetting resin (C) The resin composition (P) preferably also contains a thermosetting resin (C). In this case, thermosetting properties can be imparted to the resin composition (P). The thermosetting resin (C) preferably contains an epoxy compound (C1). In addition, as mentioned above, an epoxy compound (C1) is also a component contained in curable resin (A). Especially when the resin composition (P) includes the above-mentioned carboxyl group-containing resin (A1) and epoxy compound (C1), the carboxyl group-containing resin (A1) can react with the epoxy compound (C1) by heating.

The epoxy compound (C1) can also impart thermosetting properties to the resin composition (P). The epoxy compound (C1) preferably has at least one epoxy group in one molecule, more preferably has at least two epoxy groups in one molecule. The epoxy compound (C1) may be a poorly soluble epoxy compound in a solvent, or may be a soluble epoxy compound in a general-purpose solvent. The kind of epoxy compound (C1) is not specifically limited. The epoxy compound (C1) can contain at least one selected from the group consisting of the following compounds: phenol novolac type epoxy resin (as a specific example, model EPICLON N-775 manufactured by DIC Co., Ltd.), cresol Novolak type epoxy resin (as a specific example, model EPICLON N-695 manufactured by DIC Co., Ltd.), bisphenol A type epoxy resin (as a specific example, model jER1001 manufactured by Mitsubishi Chemical Co., Ltd.), bisphenol A - Novolac type epoxy resin (as a specific example, model EPICLON N-865 manufactured by DIC Co., Ltd.), bisphenol F-type epoxy resin (as a specific example, model jER4004P manufactured by Mitsubishi Chemical Co., Ltd.), bisphenol S type epoxy resin (as a specific example, model EPICLON EXA-1514 manufactured by DIC Co., Ltd.), bisphenol AD type epoxy resin, biphenyl type epoxy resin (as a specific example, model number manufactured by Mitsubishi Chemical Co., Ltd. YX4000), biphenyl novolak type epoxy resin (as a specific example, model NC-3000 manufactured by Nippon Kayaku Co., Ltd.), hydrogenated bisphenol A type epoxy resin (as a specific example, Nippon Steel & Sumikin Chemical Co., Ltd. Company-manufactured model ST-4000D), naphthalene-type epoxy resin (as specific examples, DIC Co., Ltd.-manufactured model EPICLON HP-4032, EPICLON HP-4700, EPICLON HP-4770), tertiary butylcatechol-type Epoxy resin (as a specific example, model EPICLON HP-820 manufactured by DIC Co., Ltd.), dicyclopentadiene type epoxy resin (as a specific example, model EPICLON HP-7200 manufactured by DIC Co., Ltd.), adamantane type Epoxy resin (as a specific example, model ADAMANTATE X-E-201 manufactured by Idemitsu Kosan Co., Ltd.), diphenyl ether type epoxy resin (as a specific example, model YSLV-80DE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) , special bifunctional epoxy resin (as specific examples, models YL7175-500 and YL7175-1000 manufactured by Mitsubishi Chemical Co., Ltd.; models EPICLON TSR-960, EPICLON TER-601, EPICLON TSR-250 manufactured by DIC Co., Ltd. -80BX, EPICLON 1650-75MPX, EPICLON EXA-4850, EPICLON EXA-4816, EPICLON EXA-4822, and EPICLON EXA-9726; model YSLV-120TE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.); 1,3,5 - Reference (2,3-epoxypropyl)-1,3,5-triazabenzene-2,4,6(1H,3H,5H)-trione; and bisphenol-based epoxy resin.

In this embodiment, it is preferable that the epoxy compound (C1) contains a crystalline epoxy resin. In this case, the developability of the coating film formed by the resin composition (P) by an alkaline aqueous solution can be improved, and an alkali containing at least one of an alkali metal salt and an alkali metal salt hydroxide can be used. An aqueous solution is used to develop the resin composition (P). Examples of crystalline epoxy resins include: 1,3,5-para(2,3-epoxypropyl)-1,3,5-triazepine-2,4,6(1H,3H ,5H)-triketone, hydroquinone type crystalline epoxy resin (as a specific example, Nippon Steel Sumikin Chemical Co., Ltd. product name YDC-1312), biphenyl type crystalline epoxy resin (as a specific example: Mitsubishi Chemical Co., Ltd. product name YX-4000), diphenyl ether type crystalline epoxy resin (as a specific example, Nippon Steel Sumikin Chemical Co., Ltd. model YSLV-80DE), bisphenol type crystalline epoxy resin Epoxy resin (as a specific example, product name YSLV-80XY manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), tetraphenol ethane type crystalline epoxy resin (as a specific example, model GTR manufactured by Nippon Kayaku Co., Ltd. -1800), a bisphenol fluorine-type crystalline epoxy resin (as a specific example, an epoxy resin having a structure represented by formula (7)).

When the resin composition (P) contains carboxyl group-containing resin (A1) and epoxy compound (C1), the ratio of epoxy compound (C1) to carboxyl group-containing resin (A1) is preferably at least 3% by mass and 70 % by mass, more preferably not less than 5% by mass and not more than 60% by mass, still more preferably not less than 10% by mass and not more than 50% by mass. Also, when the epoxy compound (C1) contains a crystalline epoxy resin, the ratio of the crystalline epoxy resin to the carboxyl group-containing resin (A1) is preferably within a range of 1% by mass to 70% by mass, More preferably, it is in the range of 3% by mass to 60% by mass, still more preferably in the range of 5% by mass to 50% by mass, and most preferably in the range of 10% by mass to 40% by mass Inside.

The thermosetting resin (C) may contain thermosetting compounds other than the above-mentioned epoxy compound (C1). Thermosetting compounds other than the thermosetting resin (C) may contain compounds such as thermosetting monomers and prepolymers other than the epoxy compound (C1), for example. The thermosetting resin (C), for example, can contain at least one selected from the group consisting of the following components: polyimide resin; polyamideimide resin; triazine resin; phenol resin; resins; urea resins; silicone resins; polyester resins; cyanate resins; oxetane resins; and, modifications of such resins.

2. Photopolymerization initiator (D) When the curable resin (A) contains a photosensitive component, that is, a photocurable resin, the resin composition (P) preferably contains a photopolymerization initiator (D). The photopolymerization initiator (D) is a compound capable of generating radicals, cations, anions, etc. by irradiation with ultraviolet rays or electron rays, and can be a polymerization reaction inducer. The photopolymerization initiator (D) is preferably a compound that can generate radicals by irradiating ultraviolet rays. The photopolymerization initiator (D), for example, can contain at least one selected from the group consisting of the following compounds: benzoin and its alkyl ethers; benzene, such as acetophenone, benzyl dimethyl ketal, etc. Ethanones; anthraquinones such as 2-methylanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 4-iso Thioxanthones such as propylthioxanthone and 2,4-diisopropylthioxanthone; diphenyl ketone, 4-benzoyl-4'-methyldiphenylsulfide, etc. Diphenyl ketones; 2,4-diisopropylxanthone and other xanthones; 2-methyl-1-[4-(methylthio)phenyl]-2-methanone Nitrogen-containing initiators such as linyl-1-acetone; 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-( 2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropane Acyl)benzyl]phenyl}-2-methylpropan-1-one, α-hydroxyalkylphenones such as methyl phenylglyoxylate; 2-methyl-1-[4- (Methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, α-aminoalkyl ketones such as 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]1-butanone ( aminoalkylphenone); 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylethylphenylphosphinate, etc. It is a photopolymerization initiator; and, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,6-dichlorobenzoyl)phenylphosphine oxide, bis( 2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2 ,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzyl Acyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, (2,5 ,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide and other acylphosphine oxide-based photopolymerization initiators; 1,2-octanedione, 1-[4 -(phenylthio)-2-(O-benzoyl oxime)], ethyl ketone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl ]-1-(O-acetyl oxime) and other oxime ester-based photopolymerization initiators. The photopolymerization initiator (D) preferably contains an acylphosphine oxide-based photopolymerization initiator. In this case, the insulation reliability of the solder resist layer formed of the insulating film-forming resin composition can be improved, and the UV sensitivity of the insulating film-forming resin composition can be improved. Especially preferably, the photopolymerization initiator (D) contains at least one selected from the group consisting of the following compounds: 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis( 2,4,6-Trimethylbenzoyl)phenylphosphine oxide. In this case, in particular, the UV sensitivity of the resin composition for insulating film formation can be improved.

The ratio of the photopolymerization initiator (D) to the carboxyl group-containing resin (A) is preferably in the range of 0.01 to 50% by mass, more preferably in the range of 0.1 to 25% by mass, still more preferably in the range of Within the range of 1 to 20% by mass.

3. Bentonite (E) In this embodiment, the resin composition (P) contains bentonite (E). As mentioned above, bentonite (E) is a component which has a layered crystal structure. The specific structure of bentonite (E) has: a tetrahedral structure composed of oxygen ions coordinated to silicon ions; a tetrahedral structure formed of oxygen ions coordinated to aluminum ions; and oxygen ions, hydroxide ions, etc. coordinated to aluminum ions , magnesium ions, iron ions, etc. constitute an octahedral structure, etc.; and the tetrahedral structure, octahedral structure, and tetrahedral structure overlap in sequence to form a layer. Bentonite (E), for example, has the following crystalline structure, which is formed by regularly stacking silicate sheets and cations in layers. The silicate sheets are negatively charged and have a thickness of about 1 nm. The cations are positively charged. Sodium ions, etc. The bentonite (E), for example, has a particle size of micron size. In the present embodiment, as described above, even if the resin composition (P) contains the bentonite (E), the viscosity of the resin composition (P) due to the bentonite (E) does not easily increase.

It is preferable that bentonite (E) contains organic bentonite (E1). Organic bentonite (E1) is capable of capturing not only inorganic cations but also organic cations such as quaternary ammonium ions, and has a characteristic of exhibiting affinity with organic solvents such as hydrocarbons. If the bentonite (E) contains the organic bentonite (E1), it is particularly easy to improve the rheology of the coating film, and it is especially difficult to increase the viscosity of the resin composition (P) due to the bentonite (E). In addition, in particular, the insulation reliability of an insulating film made of the resin composition (P) can be improved.

Examples of specific commercial items of organic bentonite (E1) are: organic bentonite manufactured by Rheox Corporation (BENTONE series (BENTONE SD-1, BENTONE SD-2, BENTONE 27, BENTONE 34, BENTONE 38)), Fengshun Organic bentonite (S-BEN series (S-BEN, S-BEN C, S-BEN E, S-BEN W, S-BEN WX), ORGANITE series (ORGANITE, ORGANITE T) manufactured by (HOJYU) Co., Ltd. , S-BEN N series (S-BEN N-400, S-BEN NX, S-BEN NX80, S-BEN NTO, S-BEN NZ, S-BEN NZ70, S-BEN NE, S-BEN NEZ, S -BEN NO12S, S-BEN NO12), organic bentonite (Orben series (Orben D, New D Orben) manufactured by Shiraishi Industry Co., Ltd., organic bentonite (KUNIVIS-110, KUNIVIS- 117), MOISTNITE-WO).

The amount of bentonite (E) is preferably not less than 0.5% by mass and not more than 5% by mass, more preferably not less than 1% by mass and not more than 3% by mass, based on the total amount of the resin composition (P). In this case, it is particularly easy to improve the rheology of the coating film, and it is particularly difficult to increase the viscosity of the resin composition (P) due to the bentonite (E). In addition, the insulation reliability of the insulating film made of the cured product of the resin composition (P) can be further improved.

Also, the amount of bentonite (E) is preferably not less than 1.5% by mass and not more than 12% by mass relative to the total amount of the first solvent (F1) and the second solvent (F2) in the resin composition (P), More preferably, it is 3 mass % or more and 10 mass % or less. In this case, it is particularly easy to improve the rheology of the coating film, and it is particularly difficult to increase the viscosity of the resin composition (P) due to the bentonite (E).

4. Solvent As mentioned above, the resin composition (P) of this embodiment contains the 1st solvent (F1) and the 2nd solvent (F2). As above, the solubility of the first solvent (F1) in 1 liter of water at 20°C is 1 g/L or more, and the solubility of the second solvent (F2) in 1 liter of water at 20°C is less than 1g.

The first solvent (F1) preferably contains a solvent having a solubility of 20 g or more in 1 liter of water at 20°C. In this case, especially the rheology of the uncured coating film made of the resin composition (P) can be improved, thereby preventing sagging of the coating film made of the resin composition (P).

Examples of the first solvent (F1) include: diethylene glycol monoethyl ether acetate (water solubility: ∞/L), propylene glycol monomethyl ethyl acetate (water solubility: 160 g/L), propylene glycol monomethyl Dipropylene glycol monomethyl ether (water solubility: ∞/L), dipropylene glycol monomethyl ether (water solubility: ∞/L), dipropylene glycol methyl ether acetate (water solubility: 190g/L) and methyl ethyl ketone (water Solubility: 29g/L), etc. The first solvent (F1) can contain at least one selected from the group consisting of these solvents. The first solvent (F1) preferably contains diethylene glycol monoethyl ether acetate. In this case, the coating film made of the resin composition (P) can be made particularly uniform without variation.

The second solvent (F2) preferably contains a solvent having a solubility of less than 500 mg in 1 liter of water at 20°C. In this case, the increase in the viscosity of the resin composition (P) can be further suppressed, and the film thickness stability of the coating film which consists of a resin composition (P) can be improved further.

Examples of the second solvent (F2) include: aromatic hydrocarbons such as toluene and xylene; petroleum-based aromatic mixed solvents such as SWASOL series (manufactured by Maruzen Petrochemical Co., Ltd.), Solvesso series (manufactured by ExxonMobil Chemical Company); Linear alkanes such as hexane; Cycloalkanes such as cyclohexane, etc. The second solvent (F2) can contain at least one selected from the group consisting of these solvents. The so-called aromatic hydrocarbons are hydrocarbons having an aromatic ring, and the so-called hydrocarbons are compounds composed of carbon and hydrogen and represented by the general formula C _n H _{2 (n-3)} . Aromatic hydrocarbons, for example: toluene, xylene, naphthalene, indene, 1,4-diethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, tetramethylbenzene, 1-methylbenzene Naphthalene, 2-methylnaphthalene, butylbenzene, methylethylbenzene, propylbenzene, methylpropylbenzene, dimethylethylbenzene, C10 aromatic hydrocarbons, C11 aromatic hydrocarbons, C12 aromatic hydrocarbons, etc. The second solvent (F2) preferably contains at least one selected from the group consisting of the aromatic hydrocarbons.

In the above-mentioned examples of the first solvent (F1) and the second solvent (F2), the so-called "water solubility" shown in parentheses means the amount dissolved in 1 liter of water at 20°C, and the so-called " ∞/L" means that they can be mixed in 1 liter of water very well, and it is the solubility that hardly separates.

In this embodiment, the total amount of the first solvent (F1) and the second solvent (F2) is 15% by mass or more and 50% by mass or less with respect to the total amount of the resin composition (P). In this case, it is possible to suppress the thickening of the resin composition (P) and contribute to the improvement of the viscosity stability, and when the coating film is formed from the resin composition (P), the film thickness of the coating film can be reduced. Uniformity improved. The total amount of the first solvent (F1) and the second solvent (F2) is more preferably 18% by mass or more and 45% by mass or less, more preferably 20% by mass with respect to the total total amount of the resin composition (P). More than 40% by mass.

In addition, in the resin composition (P), the content of the second solvent (F2) is 15% by mass or more and 50% by mass or less based on the total amount of the first solvent (F1) and the second solvent (F2). Therefore, good interaction can be formed with the bentonite (E) in the resin composition (P), and further excellent insulation reliability can be imparted to the cured film formed from the resin composition (P). The amount of the second solvent (F2), based on the total amount of the first solvent (F1) and the second solvent (F2), is more preferably 18 mass % or more and 48 mass % or less, further preferably 20 mass % or more and 46% by mass or less, preferably 22% by mass or more and 44% by mass or less. In this case, the viscosity stability, rheology, and printability of the resin composition (P) can be improved, and the resin composition can be coated with a stable film thickness. Moreover, the alkali developability of a resin composition (P) can be improved. Furthermore, more excellent insulation reliability can be provided to the cured film formed from a resin composition (P). In addition, since the suitable ratio of a solvent differs with the formation method of a coating film, it is preferable to adjust suitably so that it may satisfy|fill the said range according to the formation method of a coating film. For example, in the case of forming a dry film from a resin composition (P), when drying the coating film of the resin composition (P), it is preferable to proceed in such a manner that the organic solvent evaporates rapidly, that is, the solvent Adjustment is made so that no residue remains on the film. Also, when the resin composition (P) is applied by the screen printing method to form a coating film, the first solvent (F1) is less than the total amount of the first solvent (F1) and the second solvent (F2). ) and the second solvent (F2), the solvent having a boiling point of 160° C. or higher is preferably contained at 70% by mass or higher.

Also, as described above, a solvent can be used as a reaction solvent when synthesizing the above-described carboxyl group-containing resin (A1-1) and the like.

The resin composition (P) may contain components other than the above-described curable resin (A), photopolymerization initiator (D), bentonite (E), first solvent (F1) and second solvent (F2) . That is, the resin composition (P) can contain a carboxyl group-containing resin (A1), a photopolymerizable compound (B), an epoxy compound (C), a photopolymerization initiator (D), bentonite (E), and Components other than the first solvent (F1) and the second solvent (F2). Examples of components other than the above components include coloring agents, adhesiveness imparting agents, organic solvents, inorganic fillers, curing agents, other resins, and additives.

The resin composition (P) may contain a colorant. In this case, color can be imparted to the film formed from the resin composition (P). The coloring agent may contain, for example, a blue coloring agent and a yellow coloring agent. In this case, the coating film formed of the resin composition (P) can be made green. The colorant may contain any of pigments and dyes. Therefore, the blue colorant can be either a pigment or a dye. In addition, the yellow coloring agent may be a pigment or a dye. Also, the green colorant may be a pigment or a dye. Pigments may be inorganic particles or organometallic particles or the like. The pigment may be dispersed in the solder resist composition. Dyes can be organic compounds. The dye may be dissolved in the solder resist composition.

The colorant can be appropriately adjusted according to the color tone of the target coating and the color of the insulating layer of the printed wiring board. For example, the coloring agent may be selected from the group consisting of blue coloring agent, yellow coloring agent, black coloring agent, white coloring agent, red coloring agent, green coloring agent, purple coloring agent, orange coloring agent and brown coloring agent of more than one material.

The resin composition (P) may contain an adhesiveness imparting agent. Examples of adhesion-imparting agents include: melamine, chlorpheniramine (anamine/chlorpheniramine), acetoguanamine (2,4-diamino-6-methyl-1,3,5-triazepine Benzene), benzoguanamine (2,4-diamino-6-phenyl-1,3,5-triazepine); and, 2,4-diamino-6-methacryl Oxyethyl-s-triazepine, 2-vinyl-4,6-diamino-s-triazepine, 2-vinyl-4,6-diamino-s-triazepine s-triazepines such as benzene-isocyanuric acid adducts, 2,4-diamino-6-methacryloxyethyl-s-triazine-isocyanuric acid adducts Benzene derivatives. In this case, the adhesiveness of the solder resist layer formed from the resin composition (P) and a board|substrate can be improved.

The resin composition (P) may contain an inorganic filler. In this case, curing shrinkage of the coating film formed from the resin composition (P) can be reduced. Examples of inorganic filler materials include: barium sulfate, crystalline silica, powdered silica, nano-silica, carbon nanotubes, talc, aluminum hydroxide, magnesium hydroxide, magnesium oxide, calcium carbonate, oxide Titanium, hydrotalcite, clay, calcium silicate, mica, potassium titanate, barium titanate, aluminum nitride, boron nitride, zinc borate, aluminum borate, montmorillonite, sepiolite. The resin composition (P) and its cured product can be whitened by making the inorganic filler contain white materials such as titanium oxide and zinc oxide.

The resin composition (P) may contain a hardener for acting on the epoxy resin. Examples of hardeners can contain one or more selected from the group consisting of: imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-benzene Imidazole derivatives such as imidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, etc.; Amine, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl -Amine compounds such as N,N-dimethylbenzylamine; hydrazine compounds such as adipic hydrazine and decanoyl hydrazine; phosphorus compounds such as triphenylphosphine; acid anhydrides; phenol; mercaptans; Lewis acid amine complexes and, onium salts. Examples of commercially available products of these components include, for example: 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, and 2P4MHZ manufactured by Shikoku Chemicals Co., Ltd. (all are trade names of imidazole compounds); San-Apro Co., Ltd. U-CAT3503N, U-CAT3502T (both are trade names of blocked isocyanate compounds of dimethylamine); DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine (amidine) compounds and its salt).

The resin composition (P) may contain one or more resins selected from the group consisting of toluene diisocyanate, morpholine diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate, etc. Blocked isocyanates, which are blocked with caprolactam, oxime, malonate, etc.; melamine resin, n-butylated melamine resin, isobutylated melamine resin, butyl Amine resins such as base-based urea resins, butylated melamine-urea co-condensation resins, benzoguanazine-based co-condensation resins, etc.; various thermosetting resins other than the above; ultraviolet curable epoxy (meth)acrylates; Resins obtained by adding methacrylic acid to epoxy resins such as bisphenol A type, phenol novolac type, cresol novolak type, and alicyclic type; and, diallyl phthalate resin, benzene Polymer compounds such as oxygen resin, urethane resin, fluororesin, etc.

In addition, the resin composition (P) may contain additives other than the above, for example, one or more selected from the group consisting of the following additives: hardening accelerators; copolymers of silicone, acrylate, etc.; agent; thixotropic agent; polymerization inhibitor; antihalation agent; flame retardant; defoamer; antioxidant; surfactant; and, polymer dispersant.

5. Preparation method of resin composition for insulating film formation The resin composition (P) for forming an insulating film according to this embodiment can be obtained by mixing the following components: the above-described curable resin (A), bentonite (E), the first solvent (F1) and the second solvent. disolvent (F2); and, if necessary, a photopolymerization initiator (D).

Specifically, the raw materials of the above-mentioned resin composition (P) are prepared and kneaded by using an appropriate kneading method such as a three-roll mill, a ball mill, a sand mill, etc., to prepare the resin composition (P) ). In consideration of storage stability and the like, the first agent can be prepared by mixing a part of the components of the resin composition (P), and the second agent can be prepared by mixing the rest of the components.

In particular, when the resin composition (P) contains carboxyl group-containing resin (A1-1), it is preferred to: first prepare the carboxyl group-containing resin (A1-1), the first solvent (F1) and the second solvent (F2) The solution is prepared into a resin composition (P).

Specifically, in a solution containing the first solvent (F1), epoxy resin (a1) with novolak structure, and monocarboxylic acid (b1), make epoxy resin (a1) with novolak structure and monocarboxylic acid The acid (b1) is reacted to synthesize the intermediate (first reaction step). Next, polyhydric carboxylic acid (b2) is added to a solution, and an intermediate body and polyhydric carboxylic acid (b2) are made to react (2nd reaction process). During the reaction of the intermediate with the polycarboxylic acid (b2) (that is, before the reaction ends), the second solvent (F2) is added to the solvent. In this way, a solution of carboxyl group-containing resin (A1-1) was produced.

By synthesizing the carboxyl-containing resin (A1-1) in this way, the reaction of the novolac type epoxy resin (a1) and the monocarboxylic acid (b1) and the reaction of the intermediate and the polycarboxylic acid (b2) can be promoted, Furthermore, unreacted epoxy groups in the carboxyl group-containing resin (A1-1) can be reduced. Thereby, it becomes easy to make the epoxy equivalent of a carboxyl group-containing resin (A1-1) 8000 g/eq. or more.

In the first reaction step, the solution may or may not contain the first solvent (F1) and the second solvent (F2). When the solution contains the second solvent (F2), the amount of the first solvent (F1) in the solution is preferably 50% by mass or more relative to the total amount of the first solvent (F1) and the second solvent (F2) And 100% by mass or less. In this case, gelation of the carboxyl group-containing resin (A1-1) can be made less likely to occur when the carboxyl group-containing resin (A1-1) is synthesized.

In the second reaction step, it is preferred to add the second solvent (F2) to the solution so that the amount of the first solvent (F1) in the solution, relative to the first solvent (F1) and the second solvent The total amount of (F2) is not less than 50% by mass and not more than 95% by mass. In this case, especially the reaction between the intermediate and the polyvalent carboxylic acid (b2) can be accelerated.

A solution containing the carboxyl group-containing resin (A1-1), the first solvent (F1) and the second solvent (F2) prepared in this way is mixed with the carboxyl group-containing resin (A1-1) in the resin composition (P), Components other than the first solvent (F1) and the second solvent (F2). And according to need, at least one of the first solvent (F1) and the second solvent (F2) is further mixed to adjust the amount of the first solvent (F1) and the second solvent (F2). Thereby, the resin composition (P) was prepared.

Furthermore, the carboxyl group-containing resin (A1-1) can also be extracted by steps such as refining a solution containing the carboxyl group-containing resin (A1-1), the first solvent (F1) and the second solvent (F2). At this time, the resin composition (P) can be prepared by mixing the carboxyl group-containing resin (A1-1) and components other than the carboxyl group-containing resin (A1-1) in the resin composition (P).

Furthermore, compared with the carboxyl group-containing resin (A1-1) produced by the method other than the above mentioned from the same raw material, the carboxyl group-containing resin (A1-1) produced by the above has a larger epoxy equivalent. Therefore, the structure of the carboxyl group-containing resin (A1-1) can be specified by the above-mentioned production method.

The resin composition (P) for insulating film formation of this embodiment is suitable as an electrical insulating material for printed wiring boards. In particular, the resin composition (P) is suitable for forming an insulating film such as a solder resist layer, a plating resist layer, a resist layer, an interlayer insulating layer, and the like.

6. Manufacturing method of printed circuit board Hereinafter, an example of a method of manufacturing a printed wiring board including an interlayer insulating layer formed of a resin composition (P) in this embodiment will be described with reference to FIGS. 1A to 1E . In this method, the through hole is formed in the interlayer insulating layer by photolithography, but it is not limited to this method.

First, the core material 1 as shown in Fig. 1A is prepared. The core material 1 includes, for example, at least one insulating layer 2 and at least one conductor line 3 . Hereinafter, the conductor line 3 provided on one surface of the core material 1 is referred to as the first conductor line 3 . As shown in FIG. 1B, on one surface of the core material 1, the coating film 4 is formed from the resin composition (P). The method of forming the film 4 includes, for example, a coating method and a dry film method.

In the coating method, for example, the resin composition (P) is coated on the core material 1 to form a wet coating film. The coating method of the resin composition (P) can be selected from the group consisting of the following methods, for example: dipping method, spray method, spin coating method, roll coating method, curtain coating method and screen printing Law. Next, in order to volatilize the organic solvent in the resin composition (P), the wet coating film can be dried at a temperature in the range of, for example, 60 to 120° C., whereby the coating film 4 can be obtained.

In the dry film method, the resin composition (P) is first coated on a suitable support made of polyester and then dried, thereby forming a dried product of the resin composition (P) on the support, that is, a dry product. membrane. Thereby, a laminate (dry film with a support) is obtained, which comprises: a dry film; and a support for supporting the dry film. After the dry film in the laminate is superimposed on the core material 1, pressure is applied to the dry film and the core material 1, and then the support is peeled off from the dry film, thereby transferring the dry film from the support to the core material 1 . Thereby, the coating film 4 made of dry film is provided on the core material 1 .

By exposing the coating 4 to light, the coating 4 is partially cured as shown in FIG. 1C. In order to make the above form, for example, a negative mask is attached to the film 4, and then the film 4 is irradiated with ultraviolet rays. The negative mask includes an exposed portion that allows ultraviolet rays to pass through, and a non-exposed portion that blocks ultraviolet rays, and the non-exposed portion is provided at a position that matches 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 light source of ultraviolet rays is, for example, selected from the group consisting of 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 (LEDs), Yttrium aluminum garnet laser (YAG), g-ray (436 nm), h-ray (405 nm), i-ray (365 nm); and, a combination of two or more of g-ray, h-ray and i-ray. The light source of ultraviolet rays is not limited to these examples, and any light source may be used as long as it can irradiate ultraviolet rays capable of curing the resin composition (P).

In addition, as the exposure method, methods other than the method using a negative mask can be used. For example, the coating 4 is exposed by a direct drawing method in which only the exposed portion of the coating 4 is irradiated with ultraviolet light emitted from a light source. Light sources suitable for the direct drawing method, for example, can be selected from the group consisting of the following light sources: chemical lamps, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, xenon lamps, metal halide lamps, LEDs, YAG, g-ray (436 nm), h-ray (405 nm), i-ray (365 nm); and, a combination of two or more of g-ray, h-ray and i-ray. The light source of ultraviolet rays is not limited to these examples, and any light source may be used as long as it can irradiate ultraviolet rays capable of curing the resin composition (P).

In addition, in the dry film method, after the dry film in the laminate is superimposed on the core material 1, without peeling off the support body, the coating film 4 composed of the dry film can be irradiated with ultraviolet light through the support body. The coating 4 is exposed, and then the support is peeled off from the coating 4 before developing.

Next, by developing the coating 4, the unexposed portion 5 of the coating 4 shown in FIG. 1 C is removed, thereby forming the through hole 10 as shown in FIG. 1 D Set hole 6 in position. In the development treatment, an appropriate developer can be used depending on the composition of the resin composition (P). The developing solution is, for example, an alkaline aqueous solution or an organic amine, and the alkaline aqueous solution contains at least one of an alkali metal salt and an alkali metal hydroxide. The alkaline aqueous solution, more specifically, for example, contains at least one 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 water alone, or a mixture of water and a hydrophilic organic solvent such as a lower alcohol. The organic amine, for example, contains at least one selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine.

The developer is preferably an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide, particularly preferably an aqueous sodium carbonate solution. In this case, it is possible to improve the operating environment and reduce the burden of waste disposal.

Next, the coating 4 is hardened by heating. The heating conditions are, for example, that the heating temperature is in the range of 120 to 200° C., and the heating time is in the range of 30 to 120 minutes. By curing the coating film 4 in this way, performances such as strength, hardness, and chemical resistance of the interlayer insulating layer 7 can be improved.

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

The thickness of the interlayer insulating film 7 is not particularly limited, and may be within a range of not less than 3 μm and not more than 100 μm.

Through the above operations, the interlayer insulating layer 7 made of the cured product of the resin composition (P) is provided on the core material 1 . The second conductor line 8 and the hole plating 9 can be provided on the interlayer insulating layer 7 by an appropriate method such as an additive process. Thereby, such a printed wiring board 11 as shown in FIG. 1 E can be obtained, and the printed wiring board 11 is provided with: a first conductor circuit 3; a second conductor circuit 8; an interlayer insulating layer 7 interposed between the first conductor circuit 3 and the second conductor circuit 8 ; and, the through hole 10 is used to electrically connect the first conductor circuit 3 and the second conductor circuit 8 . In addition, in FIG. 1E , the hole plating 9 has a cylindrical shape covering the inner surface of the hole 6 , but the hole plating 9 may be filled in the entire inside of the hole 6 .

Also, before the hole plating 9 as shown in FIG. 1E is provided, the entire inner surface of the hole 6 and a part of the outer surface of the interlayer insulating layer 7 can be roughened. In this way, by roughening a part of the outer surface of the interlayer insulating layer 7 and the inner surface of the hole 6, the adhesion between the core material 1 and the hole plating 9 can be improved.

In order to roughen a part of the outer surface of the interlayer insulating layer 7 and the inner surface of the hole 6, the same procedure as the general desmear treatment using an oxidizing agent can be performed. For example, an oxidizing agent is brought into contact with the outer surface of interlayer insulating layer 7 to impart a rough surface to interlayer insulating layer 7 . However, it is not limited to this method, and the method of providing a rough surface to hardened|cured material, such as plasma treatment, UV treatment, and ozone treatment, can also be suitably used.

The oxidizing agent may be an oxidizing agent that is commercially available as a desmearing solution. For example, the oxidizing agent can be composed of a commercially available swelling solution for desmearing and desmearing liquid. Such an oxidizing agent can contain, for example, at least one permanganate selected from the group consisting of sodium permanganate and potassium permanganate.

In order to provide the hole plating 9 , electroless metal plating can be performed on the roughened part of the outer surface and the inner surface of the hole 6 to form an initial circuit. Thereafter, the metal in the electrolytic plating solution is deposited on the initial wiring by electrolytic metal plating, whereby the hole plating 9 can be formed.

An example of the method of manufacturing the printed wiring board in this embodiment provided with the solder resist layer formed from the resin composition (P) is demonstrated.

First, prepare the core material. The core material, for example, includes: at least one insulating layer and at least one conductor line. A coating is formed from the resin composition (P) on the surface of the core material on which the conductor lines are provided. The coating method and the dry film method are mentioned as a method of forming a film. As the coating method and the dry film method, the same methods as in the formation of the above-mentioned interlayer insulating layer can be employed. The film can be partially cured by exposing it to light. As the exposure method, the same method as that used for forming the above-mentioned formation of the interlayer insulating layer can also be used. Next, the unexposed portion of the coating is removed by developing the coating, whereby the exposed portion of the coating remains on the core material. Next, thermosetting is performed by heating the film on the core material. As a developing method and a heating method, the same method as when forming the above-mentioned interlayer insulating layer can also be used. If necessary, the film may be further irradiated with ultraviolet rays either before heating or after heating, or both. In this case, photocuring of the coating can be further advanced.

The thickness of the solder resist layer is not particularly limited, and may be within a range of 3 μm or more and 100 μm or less.

Through the above operations, the solder resist layer made of the cured product of the resin composition (P) can be provided on the core material. Thereby, a printed wiring board can be obtained, which includes: a core material having an insulating layer and a conductor line on the insulating layer; and a solder resist layer partially covering the surface of the core material on which the conductor line is provided. . In addition, the solder resist layer may be provided with a rough surface similarly to the above-mentioned interlayer insulating layer.

In this embodiment, the coating film of the resin composition (P) or the dry product of the resin composition (P), that is, the dry film, can form an electrically insulating insulating film particularly well, and the electrically insulating insulating film is Solder resist layer and interlayer insulating layer, etc. Even when the electrically insulating layer is provided with a rough surface, the layer of the electrically insulating layer can maintain adhesion to metal materials such as conductor lines, and has excellent electrical insulation reliability. [Example]

Hereinafter, specific examples of the present invention are mentioned. However, the present invention is not limited to these examples.

(1) Synthesis of carboxyl-containing resin (Synthesis Example A-1) In a four-necked flask equipped with a reflux cooler, a thermometer, an air blowing pipe, and a stirrer, add the following ingredients to prepare a mixture: 203 parts by mass of cresol novolak type epoxy resin (Nippon Steel & Sumitomo Metal Chemical Co., Ltd. Manufacturing, model YDCN-700-5, epoxy equivalent 203), 106 parts by mass of diethylene glycol monoethyl ether acetate, 0.2 parts by mass of methylhydroquinone, 43.2 parts by mass of acrylic acid and 3 parts by mass of Triphenylphosphine. This mixture was heated under conditions of a heating temperature of 100° C. and a heating time of 4 hours.

Then, after adding the following components to the mixture, the mixture was heated at a heating temperature of 90° C. and a heating time of 18 hours: 68 parts by mass of tetrahydrophthalic acid, 0.3 parts by mass of methylhydroquinone , 0.5 parts by mass of triphenylphosphine and 65 parts by mass of diethylene glycol monoethyl ether acetate. Furthermore, after heating, 34 parts by mass of diethylene glycol monoethyl ether acetate was added, and it heated on conditions of heating temperature 90 degreeC and heating time 5 hours. In this way, a 65% by mass solution (carboxyl group-containing resin solution A-1) of a carboxyl group-containing resin having an epoxy equivalent of 6840 g/eq. was obtained.

(Synthesis Example A-2) In a four-necked flask equipped with a reflux cooler, a thermometer, an air blowing pipe, and a stirrer, add the following ingredients to prepare a mixture: 203 parts by mass of cresol novolak type epoxy resin (Nippon Steel & Sumitomo Metal Chemical Co., Ltd. Manufacturing, model YDCN-700-5, epoxy equivalent 203), 106 parts by mass of diethylene glycol monoethyl ether acetate, 0.2 parts by mass of methylhydroquinone, 43.2 parts by mass of acrylic acid and 3 parts by mass of Triphenylphosphine. This mixture was heated under conditions of a heating temperature of 100° C. and a heating time of 4 hours.

Then, after adding the following components to the mixture, the mixture was heated at a heating temperature of 90° C. and a heating time of 18 hours: 68 parts by mass of tetrahydrophthalic acid, 0.3 parts by mass of methylhydroquinone , 0.5 parts by mass of triphenylphosphine and 29 parts by mass of diethylene glycol monoethyl ether acetate. Furthermore, after heating, 34 parts by mass of naphtha (SWASOL 1500) was added, and it heated on conditions of heating temperature 90 degreeC and heating time 5 hours. In this way, a 65% by mass solution (carboxyl group-containing resin solution A-2) of a carboxyl group-containing resin having an epoxy equivalent of 9871 g/eq. was obtained.

(Synthesis Example A-3) In a four-necked flask equipped with a reflux cooler, a thermometer, an air blowing pipe, and a stirrer, add the following ingredients to prepare a mixture: 203 parts by mass of cresol novolak type epoxy resin (Nippon Steel & Sumitomo Metal Chemical Co., Ltd. Manufacturing, model YDCN-700-5, epoxy equivalent 203), 87 parts by mass of diethylene glycol monoethyl ether acetate, 0.2 parts by mass of methylhydroquinone, 43.2 parts by mass of acrylic acid and 1 part by mass of Triphenylphosphine. This mixture was heated under conditions of a heating temperature of 100° C. and a heating time of 4 hours.

Then, after adding the following components to the mixture, the mixture was heated at a heating temperature of 90° C. and a heating time of 18 hours: 68 parts by mass of tetrahydrophthalic acid, 0.3 parts by mass of methylhydroquinone , 0.5 parts by mass of triphenylphosphine and 29 parts by mass of diethylene glycol monoethyl ether acetate. Furthermore, after heating, 53 parts by mass of naphtha (SWASOL 1500) was added, and it heated on the conditions of heating temperature 90 degreeC and heating time 5 hours. In this way, a 65% by mass solution (carboxyl group-containing resin solution A-3) of a carboxyl group-containing resin having an epoxy equivalent of 10305 g/eq. was obtained.

(Synthesis Example B-1) In a four-necked flask equipped with a reflux cooler, a thermometer, an air blowing pipe, and a stirrer, add the following ingredients to prepare a mixture: 203 parts by mass of cresol novolak type epoxy resin (Nippon Steel & Sumitomo Metal Chemical Co., Ltd. Manufacturing, model YDCN-700-5, epoxy equivalent 203), 118 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 part by mass of Triphenylphosphine. The mixture was heated at a heating temperature of 110° C. and a heating time of 15 hours.

Then, after adding the following components to the mixture, the mixture was heated at a heating temperature of 90° C. and a heating time of 5 hours. These components were: 61.6 parts by mass of tetrahydrophthalic acid, 0.3 parts by mass of methylhydroquinone And the diethylene glycol monoethyl ether acetate of 64 mass parts. Thereby, a 65% by mass solution of a carboxyl group-containing resin (carboxyl group-containing resin solution B-1) was obtained.

(2) Adjustment of resin composition The resin compositions of Examples 1-8 and Comparative Examples 1-7 were manufactured by kneading the components shown in the table|surface mentioned later by the three-roll mill, and stirring in the flask. Furthermore, the so-called "solvent (F)" shown in the table is a component including the solvent (F1) and the solvent (F2), and the organic solvents B to D in the table are contained in the solvent (F1), and the organic solvent A is included in the solvent (F2). In addition, the solvent is added as a diluting solvent to the resin composition so that its content relative to the total amount of the resin composition becomes the amount (parts by mass) shown in the columns (F1) and (F2) in the table. . In addition, the details of the components shown in the table are as follows. ‧Photopolymerizable compound: dipentaerythritol pentamethacrylate/dipentaerythritol hexamethacrylate mixture, manufactured by Nippon Kayaku Co., Ltd., model KAYARAD DPHA. ‧Photopolymerization initiator A: 2,4,6-trimethylbenzoyldiphenylphosphine oxide, manufactured by BASF, model IRGACURE TPO. ‧Photopolymerization initiator B: 1-hydroxycyclohexyl phenyl ketone (manufactured by BASF, model IRGACURE 184) ‧Photopolymerization initiator C: 2,4-dimethylthioxanthone, manufactured by Nippon Kayaku Co., Ltd., model KAYACURE DETX-S. ‧Epoxy compound A: Biphenyl type epoxy resin, manufactured by Mitsubishi Chemical Corporation, model YX4000K, pulverized with a jet mill to a maximum particle size of less than 10 μm. ‧Epoxy compound solution B: Dissolve cresol novolak type epoxy resin, EPICLON N-695 manufactured by DIC Co., Ltd., in diethylene glycol monoethyl Ether acetate/SWASOL1500 (naphtha)=1:1 solution. ‧Epoxy Compound Solution C: Dissolve cresol novolak type epoxy resin, EPICLON N-695 manufactured by DIC Co., Ltd., in diethylene glycol monoethyl A solution of ether acetate. ‧Organic bentonite: manufactured by Rheox Company, model BENTONE SD-2. ‧Powder silicon dioxide: manufactured by Tokuyama Co., Ltd., model MT-10. ‧Anion-adsorbing layered composite hydroxide: hydrotalcite. ‧Barium sulfate: manufactured by Sakai Chemical Industry Co., Ltd., model BARIACE B30. ‧Blue pigment: Phthalocyanine blue. ‧Yellow Pigment: 1,1'-[(6-Phenyl-1,3,5-Triazabenzene-2,4-diyl)bis(imido)]bis(9,10-anthraquinone ). ‧Melamine: Nissan Chemical Industry Co., Ltd., model Melamine HM. ‧Defoaming agent: polymethicone (a mixture of polydimethylsiloxane and silicic acid), manufactured by Shin-Etsu Silicone Co., Ltd., model KS-66. [dilute solvent] ‧Organic solvent A: Aromatic mixed solvent (naphtha), manufactured by Maruzen Petrochemical Co., Ltd., product name SWASOL 1500. ‧Organic solvent B: diethylene glycol monoethyl ether acetate. ‧Organic solvent C: methyl ethyl ketone. ‧Organic solvent D: Propylene glycol monomethyl ether acetate.

(3) Preparation of test piece Prepare test pieces according to the following steps. Furthermore, regarding the forming method of the thin film, for Examples 1 to 5 and Comparative Examples 1 to 5, a thin film was formed by the screen printing method as shown in the following (3-1), and for Examples 6 to 8 and Comparative Examples In Comparative Examples 6 to 7, a dry film was formed as shown in (3-2), and each of them was made into a printed wiring board as a test piece.

(3-1) Production of test pieces (screen printing method: Examples 1 to 5 and Comparative Examples 1 to 5) Using the resin composition for insulating film formation of each Example and the comparative example, the test piece was produced as follows.

First, a glass-based epoxy resin copper-clad laminate having a thickness of 17.5 μm copper foil was etched to pattern the copper foil to obtain a printed wiring board. The conductor lines of the printed wiring board were roughened by dissolving and removing the surface layer portion with a thickness of about 1 μm in the conductor lines of the printed wiring board with an etchant (model CZ-8101 manufactured by MEC Co., Ltd.).

The insulating film-forming resin compositions obtained in Examples and Comparative Examples were coated on the printed wiring board by screen printing, thereby forming a wet coating film on the printed wiring board. Preliminary drying was performed by heating the wet coating film under conditions of a heating temperature of 80° C. and a heating time of 30 minutes. Thereby, a coating film with a thickness of 20 μm was formed on the copper foil.

A negative mask was directly attached to the film, and a metal halide lamp was used to irradiate ultraviolet rays of 400 mJ/cm ² through the negative mask. In this way, the coating is selectively exposed. Next, a developing treatment is performed on the exposed film. For developing treatment, spray 1% Na ₂ CO ₃ aqueous solution at 30°C to the film for 60 seconds at a spray pressure of 0.2 MPa, and then spray pure water to the film at a spray pressure of 0.2 MPa for 60 seconds. Thereby, the part (cured film) hardened by exposure of a coating film remains on a printed wiring board. Furthermore, after heating at 150 degreeC for 60 minutes and thermosetting this cured film, the ultraviolet-ray of 1000mJ/cm ^<2> was irradiated with the high pressure mercury lamp. Thereby, a solder resist layer was formed on a printed wiring board, and the printed wiring board provided with this solder resist layer was made into a test piece.

(3-2) Production of test pieces (dry film method: Examples 6-8 and Comparative Examples 6-7) Using the resin composition for insulating film formation of each Example and the comparative example, the test piece was produced as follows.

After coating the resin composition for insulating film formation on a polyethylene terephthalate film with a coater, it is dried by heating at a temperature of 80°C and a heating time of 30 minutes after heating. , while forming a dry film with a thickness of 25 μm on the film.

A glass-based epoxy resin copper-clad laminate with a thickness of 17.5 μm copper foil was prepared. A printed wiring board (core material) was obtained by performing an etching process on this glass-epoxy resin copper-clad laminate and patterning the copper foil. However, an etchant (model CZ-8101 manufactured by MEC Co., Ltd.) was used to dissolve and remove the surface layer part with a thickness of about 1 μm in the conductor lines of the printed wiring board, thereby roughening the conductor lines. The above-mentioned dry film was heated and laminated on the entire surface of one of the printed wiring boards using a vacuum laminator. The conditions for heating the lamination were 0.5 MPa, 80° C., and 1 minute. Thereby, the coating film which consists of the said dry film is formed on the printed wiring board 4. As shown in FIG.

A negative mask was used on this film, and ultraviolet rays were irradiated with a metal halide lamp at 400 mJ/cm ² . Next, a developing treatment is performed on the exposed film. For developing treatment, spray 1% Na ₂ CO ₃ aqueous solution at 30°C to the film for 60 seconds at a spray pressure of 0.2 MPa, and then spray pure water to the film at a spray pressure of 0.2 MPa for 60 seconds. Thereby, the part (cured film) hardened by exposure of a coating film remains on a printed wiring board. In addition, the film made of polyethylene terephthalate was peeled from a dry film (coating film) before image development after exposure.

Next, after thermally hardening this cured film by heating at 150 degreeC for 60 minutes, the ultraviolet-ray of 1000mJ/cm ^<2> was irradiated with the high-pressure mercury lamp. Thereby, a solder resist layer was formed on a printed wiring board, and the printed wiring board provided with this solder resist layer was made into a test piece.

(4) Evaluation test The following evaluations were performed on the resin composition or the test piece for insulating film formation. Furthermore, in the evaluations of (4-1) to (4-5), the evaluation methods and evaluation criteria of Examples 1 to 5 and Comparative Examples 1 to 5, Embodiments 6 to 8 and Comparative Examples 6 to 7 are different, However, in the evaluations of (4-6) to (4-13), the evaluations were performed on the respective examples and comparative examples using the same evaluation method and evaluation criteria.

(4-1) Viscosity stability [Examples 1 to 5 and Comparative Examples 1 to 5: Resin compositions adjusted for screen printing] The following viscosities were measured for each prepared resin composition for insulating film formation , and evaluate each resin composition according to the following method: the viscosity measured directly after mixing with the diluent solvent (v ₀ ) and the viscosity measured after mixing with the diluent solvent after standing for 10 hours (v ₁₀ ). In addition, the viscosity was measured using a viscometer TVE-35H equipped with a 3°C×R14 impeller manufactured by Toki Sangyo Co., Ltd., and measured under the conditions of a set temperature of a constant temperature bath of 25° C. and a rotational speed of an impeller of 5 rpm. A: (v ₁₀ -v ₀ )>350dPa･s. B: 350dPa･s≦(v ₁₀ -v ₀ )>500dPa･s. C: 500dPa･s>(v ₁₀ -v ₀ ).

[Examples 6 to 8 and Comparative Examples 6 to 7: Resin compositions adjusted to dry films] The respective viscosities were measured for each resin composition for insulating film formation in the same manner as above, and determined in the following manner. Evaluation of the evaluation of the resin composition. In addition, the viscosity was measured using a viscometer TVE-35H equipped with a 1.34 degree × R24 impeller manufactured by Toki Sangyo Co., Ltd., and measured under the conditions of a set temperature of a constant temperature bath of 25° C. and a rotational speed of an impeller of 20 rpm. A: (v ₁₀ -v ₀ )>500mPa･s. B: 500mPa･s≦(v ₁₀ -v ₀ )>1000mPa･s. C: 1000mPa･s>(v ₁₀ -v ₀ ).

(4-2) Thickness stability [Examples 1 to 5 and Comparative Examples 1 to 5: Resin compositions adjusted to screen printing] For each adjusted resin composition for insulating film formation, after 10 minutes of standing still after mixing with the diluent solvent, a coating film was formed on a copper foil with a thickness of 17.5 μm by screen printing and dried. to make test coatings. The film thickness of the test coating film on the copper foil was measured at 5 points, and the average value was calculated and taken as "the film thickness of the test coating film 10 minutes after mixing the dilution solvent".

Similarly, for each adjusted resin composition for insulating film formation, after mixing with a diluent solvent and leaving it to stand for 40 minutes, a coating film was formed on a copper foil with a thickness of 17.5 μm by screen printing and dried. , to make a test coating film. The film thickness of the test coating film on the copper foil was measured at 5 points, and the average value was calculated and taken as "the film thickness of the test coating film 40 minutes after mixing the dilution solvent".

Based on the obtained "film thickness of the test coating film 10 minutes after mixing the diluent solvent" and "film thickness of the test coating film 40 minutes after mixing the diluent solvent", each resin composition was evaluated as follows. A: The difference in film thickness between "the film thickness of the test coating film 10 minutes after mixing the diluent solvent" and "the film thickness of the test coating film 40 minutes after mixing the diluent solvent" was 2 μm or less. B: The film thickness difference between "the film thickness of the test coating film 10 minutes after mixing the dilution solvent" and "the film thickness of the test coating film 40 minutes after mixing the dilution solvent" was more than 2 μm and 4 μm or less. C: The difference in film thickness between "the film thickness of the test coating film 10 minutes after mixing the diluent solvent" and "the film thickness of the test coating film 40 minutes after mixing the diluent solvent" was greater than 4 μm.

[Examples 6 to 8 and Comparative Examples 6 to 7: Resin compositions adjusted to make dry films] For each adjusted resin composition for insulating film formation, after mixing with the diluting solvent and leaving it to stand for 10 minutes, a coating film was formed on a film made of polyethylene terephthalate with a thickness of 19 μm by a coater. And it was made to dry, and the test coating film was produced. The film thickness of the test coating film on the copper foil was measured at 5 points, and the average value was calculated and taken as "the film thickness of the test coating film 10 minutes after mixing the dilution solvent".

Similarly, for each adjusted resin composition for insulating film formation, when it was left to stand for 40 minutes after being mixed with a diluent solvent, it was coated on a film made of polyethylene terephthalate with a thickness of 19 μm by using a coater. A coating film was formed and dried to prepare a test coating film. The film thickness of the test coating film on the copper foil was measured at 5 points, and the average value was calculated and taken as "the film thickness of the test coating film 40 minutes after mixing the dilution solvent".

Based on the obtained "film thickness of the test coating film 10 minutes after mixing the diluent solvent" and "film thickness of the test coating film 40 minutes after mixing the diluent solvent", each resin composition was evaluated as follows. A: The difference in film thickness between "the film thickness of the test coating film 10 minutes after mixing the diluent solvent" and "the film thickness of the test coating film 40 minutes after mixing the diluent solvent" was 2 μm or less. B: The difference in film thickness between "the film thickness of the test coating film 10 minutes after mixing the diluent solvent" and "the film thickness of the test coating film 40 minutes after mixing the diluent solvent" was more than 2 μm and 3 μm or less. C: The film thickness difference between "the film thickness of the test coating film 10 minutes after mixing the dilution solvent" and "the film thickness of the test coating film 40 minutes after mixing the dilution solvent" was more than 3 μm.

(4-3) Printing Coatability [Examples 1 to 5 and Comparative Examples 1 to 5: Resin compositions adjusted to screen printing] When preparing the test piece in (3-1) above, the coating film of the resin composition applied by screen printing was observed, and the printing coating property of the resin composition was evaluated visually and based on the following criteria. A: The coating leveling property is good and can coat uniformly. B: The coating flatness is inferior to A but coating is possible. C: Poor leveling property and uniform coating was not possible.

[Examples 6 to 8 and Comparative Examples 6 to 7: Resin composition adjusted to dry film production] When preparing the test piece in (3-2) above, observe the dry film formed by printing and coating the resin composition with a coating machine, and evaluate the printing coating of the resin composition by visual observation and according to the following criteria sex. A: The coating leveling property is good and can coat uniformly. B: The coating flatness is inferior to A but coating is possible. C: Poor leveling property and uniform coating was not possible.

In addition, since comparative examples 3 and 7 were remarkably inferior in print coatability, evaluation after "(4-6) Adhesiveness" was not implemented.

(4-4 Rheology) [Examples 1 to 5 and Comparative Examples 1 to 5: Resin compositions adjusted to screen printing] The rheological properties of the resin composition were evaluated visually and based on the following criteria by observing the test piece prepared in the above (3-1). A: Sagging (sag) of the solder resist was not found at the conductor line. B: Slight sagging of the solder resist was observed at the conductor line. C: Large sagging of the solder resist was observed at the conductor line.

[Examples 6 to 8 and Comparative Examples 6 to 7: Resin composition adjusted to dry film production] When making the test piece in (3-2) above, observe the dry film formed by coating the resin composition by printing with a coater, and evaluate the rheology of the resin composition visually and according to the following criteria. A: Generation of sagging (sagging) was not recognized in the dry film. B: Generation of slight sagging was observed in the dry film. C: Generation of large sagging was observed in the dry film.

(4-5) Range of solvent drying conditions For each of the Examples and Comparative Examples, the resin composition for forming an insulating film was coated on a flat copper substrate so that the film thickness after drying was 25 μm, and the drying temperature was 80° C. and the drying time was 60 minutes. After drying under the conditions to produce a dried coating film, the developing treatment described in (3-1) or (3-2) above is carried out.

Moreover, about each Example and a comparative example, except having changed drying time into 80 minutes, the dry coating film was produced and the image development process was performed similarly to the above.

About each said drying time (60 minutes and 80 minutes), the image development residue of the dried coating film after image development was observed, and it evaluated based on the following reference|standard. A: No image development residue was confirmed in either the dried coating film dried at 80°C for 60 minutes or the dried coating film dried at 80°C for 80 minutes. B: The image development residue was not confirmed in the dried coating film dried at 80 degreeC for 60 minutes, but the image development residue was confirmed in the dry coating film dried at 80 degreeC for 80 minutes. C: Image development residues were confirmed in both the dried coating film dried at 80° C. for 60 minutes and the dried coating film dried at 80° C. for 80 minutes.

(4-6 tightness) According to the test method defined by the Japanese Industrial Standard JIS D0202, the solder resist layer of the test piece made by the above (3) is cross-cut (cross cut) into a checkerboard mesh shape, and then the cellophane adhesive tape is used to implement Peel test. The peeling state after the test was visually observed. The results are evaluated in the manner shown below. A: There was no change at all among the 100 cross-cut sections. B: Peeling occurred at 1 to 10 of the 100 cross-cut portions. C: Peeling occurred at 11 to 100 of the 100 cross-cut portions.

(4-7) pencil hardness According to the definition of Japanese Industrial Standard JIS K5400, the pencil hardness of the solder resist layer of the test piece produced by said (3) was measured using Mitsubishi hi-uni (Mitsubishi Pencil Company) as a pencil.

(4-8) acid resistance After immersing the test piece prepared in the above (3) in 10% sulfuric acid aqueous solution at room temperature for 30 minutes, the appearance of the solder resist layer of the test piece was observed. The results are evaluated in the manner shown below. A: Abnormalities such as swelling, peeling, and discoloration were not confirmed on the solder resist layer. B: Abnormalities such as swelling, peeling, and discoloration were observed slightly on the solder resist layer. C: Abnormalities such as conspicuous swelling, peeling, and discoloration were observed on the solder resist layer.

(4-9) Soldering heat resistance Water-soluble flux (manufactured by London Chemical Co., model LONCO 3355-11) was applied on the solder resist layer of the test piece prepared by the above (3), and then the solder resist layer was immersed in a molten solder bath (solder bath) After 10 seconds, wash with water. After repeating this treatment three times, the appearance of the solder resist layer was observed, and the results were evaluated in the manner shown below. A: Abnormalities such as swelling, peeling, and discoloration were not confirmed on the solder resist layer. B: Abnormalities such as swelling, peeling, and discoloration were observed slightly on the solder resist layer. C: Abnormalities such as conspicuous swelling, peeling, and discoloration were observed on the solder resist layer.

(4-10) Plating resistance After electroless nickel plating and electroless gold plating were sequentially performed on the test piece prepared in the above (3) using a commercially available plating solution, the appearance of the plated layer and the solder resist layer was visually observed. Next, a cellophane adhesive tape peeling test was performed on the solder resist layer of this test piece to confirm the adhesion state of the solder resist layer after plating. The results were evaluated in the following manner. A: No change in appearance of the solder resist layer was observed before and after formation of the plating layer, penetration of the plating layer was not confirmed, and peeling of the solder resist layer was not confirmed in the peeling test of the cellophane adhesive tape. B: No change in the appearance of the solder resist layer was observed before and after the plating layer was formed, but partial peeling of the solder resist layer was confirmed in the cellophane adhesive tape peel test. C: Protrusion of the solder resist layer was confirmed before and after formation of the plating layer, and peeling of the solder resist layer was confirmed in the cellophane adhesive tape peel test.

(4-11) PCT (Pressure Cooker Test) The appearance of the solder resist layer of the test piece was observed after leaving the test piece prepared in the above (3) in saturated water vapor at a temperature of 121° C. for 50 hours. The results were evaluated in the following manner. A: Abnormalities such as swelling, peeling, and discoloration were not confirmed on the solder resist layer. B: Abnormalities such as swelling, peeling, and discoloration were observed slightly on the solder resist layer. C: Abnormalities such as conspicuous swelling, peeling, and discoloration were observed on the solder resist layer.

(4-12) Electrical Insulation On an FR-4 type copper-clad laminate board, comb-shaped electrodes having a line width/pitch of 100 μm/100 μm were formed to obtain a printed wiring board for evaluation. A solder resist layer was formed on this printed wiring board by the same production method and conditions as in (3) above. Next, the printed wiring board was exposed to a test environment of 121° C. and 97% RH (relative humidity) for 100 hours while applying a bias voltage of DC30 V to the comb-shaped electrodes. In this test environment, the resistance value of the solder resist layer in this environment was measured over time, and the result was evaluated based on the following evaluation criteria. A: The resistance value was maintained at 10 ⁶ Ω or more for 100 hours from the start of the test. B: The resistance value was maintained at 10 ⁶ Ω or more from the start of the test until 70 hours passed, but the resistance value became less than 10 ⁶ Ω until 100 hours passed. C: The resistance value becomes less than 10 ⁶ Ω from the start of the test until 70 hours have elapsed.

The results of the above evaluation tests are shown in Table 1 and Table 2 below.

[Table 1]

[Table 2]

(Summarize) As shown by the above results, the resin composition for forming an insulating film in the first aspect of the present invention contains: curable resin (A), bentonite (E), first solvent (F1) and second solvent ( F2). The solubility of the first solvent (F1) in 1 liter of water at 20° C. is 1 g or more, and the solubility of the second solvent (F2) in 1 liter of water at 20° C. is less than 1 g. The total amount of the first solvent (F1) and the second solvent (F2) is 15% by mass or more and 50% by mass or less with respect to the total amount of the resin composition. The quantity of the 2nd solvent (F2) is 15 mass % or more and 50 mass % or less with respect to the total quantity of the 1st solvent (F1) and the 2nd solvent (F2). According to the first aspect, in the resin composition for forming an insulating film, the viscosity of the resin composition due to the rheological agent is less likely to increase, and the insulation reliability of the insulating film made of the resin composition is less likely to be lowered. . The resin composition for forming an insulating film according to the second aspect is the first aspect, wherein the curable resin composition (A) contains a carboxyl group-containing resin (A1-1), and the carboxyl group-containing resin (A1-1) It is formed by addition-reacting a monocarboxylic acid (b1) to a part of the epoxy group of an epoxy resin (a1) having a novolac structure, and adding a polycarboxylic acid (b2) to another part of the epoxy group . According to the second aspect, the film thickness stability of the coating film formed from the resin composition can be further improved. Furthermore, an insulating layer formed of a cured product of the resin composition can have even more excellent insulating reliability. The resin composition for insulating film formation of a 3rd aspect is the 2nd aspect in which the monocarboxylic acid (b1) contains acrylic acid. According to the third aspect, the sticking of the wet coating film formed by the resin composition can be sufficiently suppressed, and the plating resistance, soldering heat resistance, and insulation reliability of insulating layers such as interlayer insulating layers and solder resist layers can be improved. sex. The resin composition for insulating film formation of the 4th aspect is aimed at the 2nd or 3rd aspect, wherein the polyhydric carboxylic acid (b2) contains tetrahydrophthalic acid. According to the fourth aspect, the water absorption of the interlayer insulating layer formed of the resin composition, the solder resist layer, and the like can be reduced, thereby improving the plating resistance and insulation reliability of the insulating layer. The resin composition for forming an insulating film according to the fifth aspect is directed to any one of the second to fourth aspects, wherein the carboxyl group-containing resin (A1-1) is a reactant, and the reactant is dissolved in a solvent An intermediate obtained by reacting an epoxy resin (a1) having a novolak structure with a monocarboxylic acid (b1) and a polycarboxylic acid (b2) in the presence of (F2). According to the fifth aspect, the viscosity of the resin composition can be prevented from excessively increasing, and the rheology of the coating film formed of the resin composition can be maintained well. Moreover, according to this aspect, the developability of the coating film made from a resin composition can be improved. The resin composition for forming an insulating film according to the sixth aspect is any one of the second to fifth aspects, wherein the carboxyl group-containing resin (A1-1) has an epoxy equivalent of 8000 g/eq. or more . According to the sixth aspect, the viscosity of the resin composition can be prevented from excessively increasing, and the rheology of the coating film formed of the resin composition can be well maintained. Furthermore, it can contribute to making the insulating reliability of the insulating film containing the hardened|cured material of a resin composition less likely to fall. The resin composition for forming an insulating film according to a seventh aspect is any one of the first to sixth aspects, wherein the first solvent (F1) contains diethylene glycol monoethyl ether acetate. According to the seventh aspect, the coating film made of the resin composition can be made particularly uniform without variation. The resin composition for forming an insulating film according to an eighth aspect is any one of the first to seventh aspects, wherein the second solvent (F2) contains an aromatic hydrocarbon. According to the eighth aspect, it is possible to suppress the thickening of the resin composition and contribute to improving the viscosity stability. In addition, when the coating film is formed from a resin composition, the uniformity of the film thickness of the coating film can be further improved. The resin composition for forming an insulating film according to the ninth aspect is any one of the first to eighth aspects, wherein the amount of bentonite (E) is equal to the total amount of the resin composition for forming an insulating film. The amount is not less than 0.5% by mass and not more than 5% by mass. According to the ninth aspect, it is particularly easy to improve the rheology of the coating film, and it is particularly difficult to increase the viscosity of the resin composition due to the bentonite (E). In addition, the insulation reliability of the insulating layer formed of the cured product of the resin composition can be further improved. The resin composition for forming an insulating film according to the tenth aspect is any one of the first to ninth aspects, wherein the amount of the bentonite (E) is equal to the amount of the first solvent (F1) and the second solvent (F1). The total amount of the solvent (F2) is not less than 1.5% by mass and not more than 12% by mass. According to the tenth aspect, it is particularly easy to improve the rheology of the coating film, and it is particularly difficult to increase the viscosity of the resin composition due to the bentonite (E). The method for producing a resin composition for forming an insulating film according to an eleventh aspect is a method for producing the composition for forming an insulating film according to any one of the first to tenth aspects, and the production method includes The step of manufacturing carboxyl group-containing resin (A1-1), the step is: in the solution containing first solvent (F1), epoxy resin (a1) having novolac structure and monocarboxylic acid (b1), making The epoxy resin (a1) of the varnish structure is reacted with the monocarboxylic acid (b1) to synthesize an intermediate, and then the polycarboxylic acid (b2) is added to the solution to react the intermediate with the polycarboxylic acid (b2), and During the reaction of the intermediate and the aforementioned polycarboxylic acid (b2), the second solvent (F2) is added to the solution, whereby the carboxyl group-containing resin (A1-1) is produced. According to the eleventh aspect, it is possible to obtain a resin composition for forming an insulating film, which is less likely to cause an increase in the viscosity of the resin composition due to the rheological agent, and which can reduce the viscosity of the insulating film made of the resin composition. Insulation reliability is not easily reduced. The dry film of the twelfth aspect is a dried product of the composition for forming an insulating film according to any one of the first to tenth aspects. According to the twelfth aspect, even if it is made into a cured product, it is difficult to reduce the insulation reliability of the insulating film. In addition, electrically insulating insulating films such as solder resist layers and interlayer insulating layers can be formed particularly favorably from this dry film. A printed wiring board according to a thirteenth aspect is provided with an insulating film containing a cured product of the composition for forming an insulating film according to any one of the first to tenth aspects. According to the thirteenth aspect, the printed wiring board has excellent electrical insulation reliability. The printed wiring board of the fourteenth aspect is the thirteenth aspect, wherein the insulating film is an interlayer insulating layer or a solder resist layer. According to the fourteenth aspect, the printed wiring board has more excellent electrical insulation reliability. A method of manufacturing a printed wiring board according to a fifteenth aspect, the printed wiring board includes a conductor line and an insulating film overlapping the conductor line; and the manufacturing method includes any one of the first to tenth aspects The step of forming the aforementioned insulating film using the composition for forming the insulating film described above. According to the fifteenth aspect, a printed wiring board having excellent insulation reliability can be obtained.

1: core material 2: Insulation layer 3: The first conductor line 4: Laminating 5: Unexposed part of film 4 6: hole 7: Interlayer insulating layer 8: Second conductor line 9: Hole Plating 10: Through hole 11: Printed circuit board

Fig. 1 A is a cross-sectional view schematically showing the steps of manufacturing a printed wiring board in one embodiment of the present invention. Fig. 1B is a cross-sectional view schematically showing the steps of manufacturing a printed wiring board in one embodiment of the present invention. Fig. 1C is a cross-sectional view schematically showing the steps of manufacturing a printed wiring board according to an embodiment of the present invention. FIG. 1D is a cross-sectional view schematically showing the steps of manufacturing a printed wiring board in one embodiment of the present invention. FIG. 1E is a cross-sectional view schematically showing the steps of manufacturing a printed wiring board in one embodiment of the present invention.

Domestic deposit information (please note in order of depositor, date, and number) none

Overseas storage information (please note in order of storage country, organization, date, and number) none

1: core material

2: Insulation layer

3: The first conductor line

4: Laminating

Claims (13)

A resin composition for forming an insulating film, comprising: a curable resin (A), bentonite (E), a first solvent (F1) and a second solvent (F2); the curable resin (A) contains a carboxyl group-containing Resin (A1-1), the carboxyl group-containing resin (A1-1) is the epoxy group of a part of the epoxy resin (a1) having a novolac structure in which the monocarboxylic acid (b1) is added and reacted, and the polycarboxylic acid The acid (b2) is formed by an addition reaction on another part of epoxy groups; the solubility of the aforementioned first solvent (F1) relative to 1 liter of water at 20°C is 1 g or more, and the aforementioned second solvent (F2) has a solubility at 20 °C. The solubility in 1 liter of water at °C is less than 1 g; and the total amount of the first solvent (F1) and the second solvent (F2) is 15% by mass relative to the total amount of the resin composition More than 50% by mass; The amount of the second solvent (F2) is 15% by mass to 50% by mass relative to the total amount of the first solvent (F1) and the second solvent (F2); The quantity of bentonite (E) is 1.5 mass % or more and 12 mass % or less with respect to the total amount of the said 1st solvent (F1) and the said 2nd solvent (F2). The resin composition for forming an insulating film according to claim 1, wherein the monocarboxylic acid (b1) contains acrylic acid. Tree for forming an insulating film as described in claim 1 or 2 A lipid composition wherein the polyvalent carboxylic acid (b2) contains tetrahydrophthalic acid. The resin composition for forming an insulating film as described in claim 1 or 2, wherein the aforementioned carboxyl group-containing resin (A1-1) is a reactant, and the reactant is made into an intermediate in the presence of a solvent (F2). It is obtained by reacting with polycarboxylic acid (b2), and the intermediate is obtained by reacting epoxy resin (a1) having a novolak structure with monocarboxylic acid (b1). The resin composition for forming an insulating film according to claim 1 or 2, wherein the epoxy equivalent of the carboxyl group-containing resin (A1-1) is 8000 g/eq. or more. The resin composition for forming an insulating film according to claim 1 or 2, wherein the first solvent (F1) contains diethylene glycol monoethyl ether acetate. The resin composition for forming an insulating film according to claim 1 or 2, wherein the second solvent (F2) contains an aromatic hydrocarbon. The resin composition for forming an insulating film according to claim 1 or 2, wherein the amount of the above-mentioned bentonite (E) is 0.5% by mass or more and 5% by mass relative to the total amount of the resin composition for forming an insulating film. Mass% or less. A method for producing a resin composition for forming an insulating film, the resin composition for forming an insulating film is the resin composition for forming an insulating film described in any one of Claims 1 to 8, the production method comprising: The step of making carboxyl-containing resin (A1-1), the step is: in the solution containing the aforementioned first solvent (F1), the aforementioned epoxy resin (a1) having a novolac structure, and the aforementioned monocarboxylic acid (b1), The above-mentioned epoxy resin (a1) having a novolak structure is reacted with the above-mentioned monocarboxylic acid (b1) to synthesize an intermediate, and the above-mentioned polycarboxylic acid (b2) is added to the above-mentioned solution to make the above-mentioned intermediate and the above-mentioned polycarboxylic acid Acid (b2) is reacted, and during the reaction process of the aforementioned intermediate and the aforementioned polycarboxylic acid (b2), the aforementioned second solvent (F2) is added to the aforementioned solution, thereby producing the carboxyl group-containing resin (A1-1) . A dry film, which is a dried product of the resin composition for forming an insulating film according to any one of claims 1 to 8. A printed wiring board comprising an insulating film containing a cured product of the resin composition for forming an insulating film according to any one of claims 1 to 8. The printed wiring board according to claim 11, wherein the insulating film is an interlayer insulating film or a solder resist layer. A method of manufacturing a printed wiring board, the printed wiring board having a conductor line and an insulating film overlapping the conductor line; and, the manufacturing method includes the insulating film forming method described in any one of Claims 1 to 8 The step of making the aforementioned insulating film with the resin composition.