WO2017125967A1 - Dry film laminated body - Google Patents

Abstract

A dry film laminated body (15) relating to the present invention is provided with a base film (12), a dry film (13), and a cover film (14), which are laminated in this order. The base film (12) is a polyethylene terephthalate film, the dry film (13) contains a carboxyl group-containing resin (A) and a crystalline epoxy resin (B1). The cover film (14) is an oriented polypropylene film.

Description

Dry film laminate

The present invention relates to a dry film laminate.

Conventionally, various electrically insulating resin compositions have been used to form electrically insulating layers such as solder resist layers, plating resist layers, etching resist layers, and interlayer insulating layers of printed wiring boards. Such a resin composition is, for example, a resin composition containing a carboxyl group-containing resin. Moreover, in order to provide thermosetting to a resin composition, it is performed to contain an epoxy resin (refer patent 4508929).

Resin compositions are often stored in the form of dry films. A dry film is formed on the base film by applying a resin composition or the like on the base film. A dry film laminate is obtained by pressure-bonding a cover film to the dry film. This dry film laminate is stored, for example, in a roll.

However, an epoxy resin may be deposited between the outer surface of the base film and the outer surface of the cover film during storage of the dry film laminate. Therefore, the composition of the dry film is changed, and there is a problem in the storage stability of the dry film.

Also, the epoxy resin deposited from the dry film laminate may become powder and adhere to the dry film. Therefore, when the dry film laminate is used in a clean room where particularly high contamination control is required, there is a problem that the powder falls off the dry film laminate and contaminates the clean room.

An object of the present invention is to provide a dry film laminate capable of suppressing the precipitation of an epoxy resin on the outer surface of the dry film laminate and the generation of powder composed of the epoxy resin.

The dry film laminate according to one embodiment of the present invention includes a base film, a dry film, and a cover film, which are laminated in this order, the base film is a polyethylene terephthalate film, and the dry film is A carboxyl group-containing resin (A) and a crystalline epoxy resin (B1) are contained, and the cover film is a stretched polypropylene film.

According to one embodiment of the present invention, it is possible to suppress the precipitation of the epoxy resin on the outer surface of the dry film laminate and the generation of the powder made of the epoxy resin.

FIG. 1 is a cross-sectional view showing a dry film laminate according to an embodiment of the present invention. 2A to 2F are cross-sectional views showing a process for producing a multilayer printed wiring board from the above dry film laminate.

Hereinafter, an embodiment of the present invention will be described. 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.

As shown in FIG. 1, the dry film laminate 15 according to the present embodiment includes a base film 12, a dry film 13, and a cover film 14, which are laminated in this order. The base film 12 is a polyethylene terephthalate film. The dry film 13 contains a carboxyl group-containing resin (A) and an epoxy compound (B), and the epoxy compound (B) contains a crystalline epoxy resin (B1). That is, the dry film 13 contains a carboxyl group-containing resin (A) and a crystalline epoxy resin (B1). The cover film 14 is a stretched polypropylene film.

The dry film 13 has thermosetting properties by containing the carboxyl group-containing resin (A) and the crystalline epoxy resin (B1).

Conventionally, the cover film in the dry film laminate is usually a polyethylene film that is easily peeled off from the dry film. However, the present inventors, in particular, when the dry film contains a crystalline epoxy resin, the crystalline epoxy resin in the dry film permeates the polyethylene film and precipitates on the outer surface of the dry film laminate. I found out.

As a result of intensive studies, the present inventors have found that the above problem can be solved by applying a stretched polypropylene film as the cover film 14.

The stretched polypropylene film may be either a uniaxially stretched polypropylene film or a biaxially stretched polypropylene film, but is preferably a biaxially stretched polypropylene film.

If the cover film 14 is a stretched polypropylene film, the cover film 14 is difficult to transmit the crystalline epoxy resin. For this reason, the composition change of the dry film 13 can be suppressed by suppressing the precipitation of the epoxy resin on the outer surface of the dry film laminate 15. Thereby, the storage stability of the dry film laminate 15 is improved. Further, when the precipitation of the epoxy resin is suppressed in this way, the generation of the powder made of the epoxy resin on the outer surface of the dry film laminate 15 can also be suppressed. In addition, good peelability between the cover film 14 and the dry film 13 can be ensured.

Hereinafter, the components contained in the dry film 13 of the present embodiment will be specifically described.

First, the carboxyl group-containing resin (A) will be specifically described.

The carboxyl group-containing resin (A) may be anything as long as it has a carboxyl group.

The carboxyl group-containing resin (A) preferably contains a reaction product of a polyol compound and a polyvalent carboxylic acid.

The polyol compound may be a compound having two or more hydroxyl groups. The polyol compound includes, for example, an addition reaction product of an epoxy resin having two or more epoxy groups and a carboxylic acid. This addition reaction product has a hydroxyl group generated by an addition reaction between an epoxy group in an epoxy resin and a carboxyl group in a carboxylic acid.

The polycarboxylic acid is at least one of, for example, a polybasic acid and a polybasic acid anhydride. The polyvalent carboxylic acids can contain at least one compound selected from the group consisting of polyvalent carboxylic acids such as phthalic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid, and anhydrides of these polyvalent carboxylic acids. .

The polymerization average molecular weight of the reaction product of the polyol compound and the polyvalent carboxylic acid is preferably in the range of 700 to 40,000. When the weight average molecular weight is 700 or more, the tackiness of the dry film 13 can be further suppressed, and the insulation reliability and plating resistance of the cured product can be further improved. Further, when the weight average molecular weight is 40000 or less, the developability of the dry film 13 with an alkaline aqueous solution is particularly improved. The weight average molecular weight is calculated from the measurement result of molecular weight under the following conditions by gel permeation chromatography.

GPC device: SHODEX SYSTEM 11, manufactured by Showa Denko KK
Column: 4 series of SHODEX KF-800P, KF-005, KF-003, KF-001,
Mobile phase: THF,
Flow rate: 1 ml / min
Column temperature: 45 ° C
Detector: RI,
Conversion: Polystyrene.

The acid value of the reaction product of the polyol compound and the polyvalent carboxylic acid is preferably in the range of 50 to 200 mg KOH / g. In this case, the developability of the dry film 13 is particularly improved. The acid value is more preferably in the range of 60 to 140 mgKOH / g, still more preferably in the range of 80 to 135 mgKOH / g, and particularly preferably in the range of 90 to 130 mgKOH / g.

The reaction product of the polyol compound and the polycarboxylic acid preferably contains, for example, a carboxyl group-containing resin (A1) having a bisphenolfluorene skeleton. That is, the carboxyl group-containing resin (A) preferably contains a carboxyl group-containing resin (A1). In this case, high heat resistance and plating resistance can be imparted to the cured product of the dry film 13. The carboxyl group-containing resin (A1) is, for example, a reaction product of an intermediate obtained by reacting an epoxy compound (a1) with an unsaturated group-containing carboxylic acid (a2) and an acid anhydride. The epoxy compound (a1) is represented by the following formula (1), and in the formula (1), R ₁ to R ₈ are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or halogen, and a bisphenolfluorene skeleton Have

The carboxyl group-containing resin (A1) is synthesized by reacting the epoxy compound (a1) with the unsaturated group-containing carboxylic acid (a2), and reacting the resulting intermediate with an acid anhydride. The

Each of R ₁ to R ₈ in Formula (1) may be hydrogen, but may be an alkyl group having 1 to 5 carbon atoms, or halogen. This is because even if hydrogen in the aromatic ring is substituted with a low molecular weight alkyl group or halogen, the physical properties of the carboxyl group-containing resin (A1) are not adversely affected, but rather the photosensitive resin composition containing the carboxyl group-containing resin (A1). This is because the heat resistance or flame retardancy of the cured product may be improved.

The carboxyl group-containing resin (A1) will be described more specifically. In order to synthesize the carboxyl group-containing resin (A1), first, at least a part of the epoxy group (see formula (2)) of the epoxy compound (a1) is reacted with the unsaturated group-containing carboxylic acid (a2). The intermediate is then synthesized. The intermediate has a structure (S3) represented by the following formula (3) generated by a ring-opening addition reaction between an epoxy group and an unsaturated group-containing carboxylic acid (a2). That is, the intermediate has a secondary hydroxyl group generated by a ring-opening addition reaction between an epoxy group and an unsaturated group-containing carboxylic acid (a2) in the structure (S3). In Formula (3), A is an unsaturated group-containing carboxylic acid residue.

Next, the secondary hydroxyl group in the intermediate is reacted with an acid anhydride. Thereby, carboxyl group-containing resin (A1) can be synthesized.

The acid anhydride may contain, for example, at least one of acid dianhydride (a3) and acid monoanhydride (a4). When the acid anhydride contains acid monoanhydride (a4), the carboxyl group-containing resin (A1) has a bisphenolfluorene skeleton (S1) represented by the formula (1) and a structure (S4) represented by the following formula (4). And have.

The structure (S4) is generated by the reaction between the secondary hydroxyl group in the intermediate structure (S3) and the acid anhydride group in the acid monoanhydride (a4). In Formula (4), A is an unsaturated group-containing carboxylic acid residue, and B is an acid monoanhydride residue.

When the acid anhydride contains an acid dianhydride (a3), the carboxyl group-containing resin (A1) has a bisphenolfluorene skeleton (S1) and a structure (S5) represented by the following formula (5).

Structure (S5) is generated by the reaction between two acid anhydride groups in acid dianhydride (a3) and two secondary hydroxyl groups in the intermediate. That is, the structure (S5) is generated by crosslinking the two secondary hydroxyl groups with the acid dianhydride (a3). In addition, the case where two secondary hydroxyl groups present in one molecule of the intermediate are crosslinked and the case where two secondary hydroxyl groups present in each of the two molecules of the intermediate are crosslinked It is possible. When the two secondary hydroxyl groups present in the two molecules of the intermediate are cross-linked, the molecular weight increases. In Formula (5), A is an unsaturated group-containing carboxylic acid residue, and D is an acid dianhydride residue.

A secondary hydroxyl group in the intermediate and an acid anhydride can be reacted to obtain a carboxyl group-containing resin (A1). When the acid anhydride contains an acid dianhydride (a3) and an acid monoanhydride (a4), a part of the secondary hydroxyl groups in the intermediate are reacted with the acid dianhydride (a3). , Another part of the secondary hydroxyl group in the intermediate is reacted with acid monoanhydride (a4). Thereby, carboxyl group-containing resin (A1) can be synthesized. In this case, the carboxyl group-containing resin (A1) has a bisphenolfluorene skeleton (S1), a structure (S4), and a structure (S5).

The carboxyl group-containing resin (A1) may further have a structure (S6) represented by the following formula (6). The structure (S6) occurs when only one of the two acid anhydride groups in the acid dianhydride (a3) reacts with the secondary hydroxyl group in the intermediate. In Formula (6), A is an unsaturated group-containing carboxylic acid residue, and D is an acid dianhydride residue.

When some of the epoxy groups in the epoxy compound (a1) remain unreacted during the synthesis of the intermediate, the carboxyl group-containing resin (A1) has the structure (S2) represented by the formula (2), that is, the epoxy group Can have. Further, when a part of the structure (S3) in the intermediate remains unreacted, the carboxyl group-containing resin (A1) may have the structure (S3).

When the acid anhydride contains acid dianhydride (a3), the structure (S2) in the carboxyl group-containing resin (A1) is optimized by optimizing the reaction conditions during the synthesis of the carboxyl group-containing resin (A1). In addition, the number of structures (S6) is reduced, or the structure (S2) and the structure (S6) are almost eliminated from the carboxyl group-containing resin (A1).

As described above, the carboxyl group-containing resin (A1) has a bisphenolfluorene skeleton (S1), and has a structure (S4) when the acid anhydride contains acid monoanhydride (a4). When a thing contains an acid dianhydride (a3), it can have a structure (S5). Further, when the acid anhydride contains acid monoanhydride (a4), the carboxyl group-containing resin (A1) may have at least one of the structure (S2) and the structure (S3). Moreover, when an acid anhydride contains an acid dianhydride (a3), carboxyl group-containing resin (A1) may have at least 1 type in a structure (S2) and a structure (S6). Furthermore, when the acid anhydride contains acid monoanhydride (a4) and acid dianhydride (a3), the carboxyl group-containing resin (A1) has a structure (S2), a structure (S3), a structure ( And at least one of S6).

When the epoxy compound (a1) itself has a secondary hydroxyl group, that is, for example, when n = 1 or more in the formula (7) described later, the carboxyl group-containing resin (A1) is an epoxy compound (a1). ) In which a secondary hydroxyl group and an acid anhydride react with each other.

In addition, the structure of the above-mentioned carboxyl group-containing resin (A1) is reasonably inferred based on the common general technical knowledge, and the structure of the carboxyl group-containing resin (A1) cannot be specified by analysis. The reason is as follows. When the epoxy compound (a1) itself has a secondary hydroxyl group (for example, when n is 1 or more in the formula (7)), the carboxyl group-containing resin depends on the number of secondary hydroxyl groups in the epoxy compound (a1). The structure of (A1) changes greatly. When the intermediate and the acid dianhydride (a3) react, as described above, two secondary hydroxyl groups present in one molecule of the intermediate are acid dianhydrides (a3). There may be a case where two secondary hydroxyl groups respectively present in two molecules of the intermediate are crosslinked with an acid dianhydride (a3). For this reason, the carboxyl group-containing resin (A1) finally obtained contains a plurality of molecules having different structures, and even when the carboxyl group-containing resin (A1) is analyzed, the structure cannot be specified.

Since the carboxyl group-containing resin (A1) has an ethylenically unsaturated group derived from the unsaturated group-containing carboxylic acid (a2), it is photoreactive when the photopolymerization initiator (D) described later is used in combination. Have For this reason, the carboxyl group-containing resin (A1) can impart photosensitivity (specifically, ultraviolet curing) to the dry film 13. Moreover, since the carboxyl group-containing resin (A1) has a carboxyl group derived from an acid anhydride, the dry aqueous solution 13 contains at least one of an alkali metal salt and an alkali metal hydroxide. Developability can be imparted. Furthermore, when the acid anhydride contains an acid dianhydride (a3), the molecular weight of the carboxyl group-containing resin (A1) depends on the number of crosslinks by the acid dianhydride (a3). For this reason, the carboxyl group-containing resin (A1) in which the acid value and the molecular weight are appropriately adjusted is obtained. When the acid anhydride contains acid dianhydride (a3) and acid dianhydride (a4), the amount of acid dianhydride (a3) and acid dianhydride (a4), and acid dianhydride ( By controlling the amount of acid monoanhydride (a4) relative to a3), a carboxyl group-containing resin (A1) having a desired molecular weight and acid value can be easily obtained.

The raw material of the carboxyl group-containing resin (A1) and the reaction conditions during the synthesis of the carboxyl group-containing resin (A1) will be described in detail.

The epoxy compound (a1) has a structure (S7) represented by the following formula (7), for example. N in the formula (7) is a number in the range of 0 to 20, for example. In order to set the molecular weight of the carboxyl group-containing resin (A1) to an appropriate value, the average of n is particularly preferably in the range of 0-1. If the average of n is in the range of 0 to 1, particularly when the acid anhydride contains acid dianhydride (a3), an excessive increase in molecular weight due to the addition of acid dianhydride (a3) is suppressed. It becomes easy.

The unsaturated group-containing carboxylic acid (a2) can contain, for example, a compound having only one ethylenically unsaturated group in one molecule. More specifically, unsaturated group-containing carboxylic acid (a2) is, for example, acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≈2) monoacrylate, crotonic acid, cinnamic acid, 2-acryloyloxyethyl succinate. Acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl phthalic acid, 2-acryloyloxypropyl phthalic acid, 2-methacryloyloxypropyl phthalic acid, 2-acryloyloxyethyl maleic acid, 2-methacryloyloxyethyl maleic acid, β-carboxyethyl acrylate, 2-acryloyloxyethyl tetrahydrophthalic acid, 2-methacryloyloxyethyl tetrahydrophthalic acid, 2-acryloyloxyethyl hexahydrophthalic acid And at least one compound selected from the group consisting of 2-methacryloyloxyethyl hexahydrophthalic acid. Preferably, unsaturated group containing carboxylic acid (a2) contains acrylic acid.

In reacting the epoxy compound (a1) with the unsaturated group-containing carboxylic acid (a2), a known method may be employed. For example, the reactive solution is obtained by adding the unsaturated group-containing carboxylic acid (a2) to the solvent solution of the epoxy compound (a1), further adding a thermal polymerization inhibitor and a catalyst as necessary, and stirring and mixing. An intermediate can be obtained by reacting this reactive solution at a temperature of preferably 60 to 150 ° C., particularly preferably 80 to 120 ° C., by a conventional method. Solvents include, for example, ketones such as methyl ethyl ketone and cyclohexanone, and aromatic hydrocarbons such as toluene and xylene, and ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether It can contain at least one component selected from the group consisting of acetates such as acetate and dialkyl glycol ethers. The thermal polymerization inhibitor contains, for example, at least one of hydroquinone and hydroquinone monomethyl ether. The catalyst is selected from the group consisting of tertiary amines such as benzyldimethylamine and triethylamine, quaternary ammonium salts such as trimethylbenzylammonium chloride and methyltriethylammonium chloride, triphenylphosphine, and triphenylstibine. It can contain at least one component.

The catalyst particularly preferably contains triphenylphosphine. That is, it is preferable to react the epoxy compound (a1) with the unsaturated group-containing carboxylic acid (a2) in the presence of triphenylphosphine. In this case, the ring-opening addition reaction between the epoxy group and the unsaturated group-containing carboxylic acid (a2) in the epoxy compound (a1) is particularly accelerated, and the reaction rate (conversion) is 95% or more, 97% or more, or almost 100%. Rate). For this reason, the intermediate body which has a structure (S3) is obtained with a high yield. In addition, the occurrence of ion migration in the layer containing the cured product of the dry film 13 is suppressed, and the insulation reliability of the same layer is further improved.

When the epoxy compound (a1) and the unsaturated group-containing carboxylic acid (a2) are reacted, the amount of the unsaturated group-containing carboxylic acid (a2) relative to 1 mol of the epoxy group of the epoxy compound (a1) is 0.8 to 1. It is preferably within a range of 2 moles. In this case, the dry film 13 having excellent photosensitivity and storage stability is obtained.

It is also preferable to react the epoxy compound (a1) and the unsaturated group-containing carboxylic acid (a2) under air bubbling. In this case, since the addition polymerization reaction of the unsaturated group is suppressed, the increase in the molecular weight of the intermediate and the gelation of the intermediate solution can be suppressed. Moreover, the excessive coloring of carboxyl group-containing resin (A1) which is a final product can be suppressed.

The intermediate thus obtained comprises a hydroxyl group generated by a reaction between the epoxy group of the epoxy compound (a1) and the carboxyl group of the unsaturated group-containing carboxylic acid (a2).

Acid dianhydride (a3) is a compound having two acid anhydride groups. The acid dianhydride (a3) can contain an anhydride of tetracarboxylic acid. Acid dianhydride (a3) is, for example, 1,2,4,5-benzenetetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, methylcyclohexene tetracarboxylic dianhydride, tetracarboxylic dianhydride, Naphthalene-1,4,5,8-tetracarboxylic dianhydride, ethylenetetracarboxylic dianhydride, 9,9'-bis (3,4-dicarboxyphenyl) fluorene dianhydride, glycerin bisanhydrotri Melitate monoacetate, ethylene glycol bisanhydro trimellitate, 3,3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5 (tetrahydro -2,5-dioxo-3-furanyl) naphtho [1,2-c] furan-1,3-dione, 1,2,3,4-buta Tetracarboxylic dianhydride, and 3,3 ', may contain at least one compound selected from the group consisting of 4,4'-biphenyl tetracarboxylic acid dianhydride. In particular, the acid dianhydride (a3) preferably contains 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride. That is, it is preferable that D in Formula (5) and Formula (6) includes a 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride residue. In this case, while ensuring good developability of the dry film 13, it is possible to further suppress the tackiness of the dry film 13 and further improve the insulation reliability and plating resistance of the cured product. The amount of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride with respect to the total amount of acid dianhydride (a3) is preferably in the range of 20 to 100 mol%, and is preferably 40 to 100 mol%. Although it is more preferable to be within the range, it is not limited to these ranges.

Acid monoanhydride (a4) is a compound having one acid anhydride group. The acid monoanhydride (a4) can contain an anhydride of a dicarboxylic acid. Examples of the acid monoanhydride (a4) include phthalic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic acid anhydride, hexahydrophthalic anhydride, methylhexa Hydrophthalic anhydride, succinic anhydride, methyl succinic anhydride, maleic anhydride, citraconic anhydride, glutaric anhydride, trimellitic anhydride, cyclohexane-1,2,4-tricarboxylic acid-1, It can contain at least one compound selected from the group consisting of 2-anhydride and itaconic anhydride. In particular, it is preferable that the acid monoanhydride (a4) contains 1,2,3,6-tetrahydrophthalic anhydride. That is, the acid anhydride preferably contains 1,2,3,6-tetrahydrophthalic anhydride. That is, it is preferable that the carboxyl group-containing resin (A1) has the structure (S4), and B in the formula (4) includes a 1,2,3,6-tetrahydrophthalic anhydride residue. In this case, while ensuring good developability of the dry film 13, it is possible to further suppress the tackiness of the dry film 13 and further improve the insulation reliability and plating resistance of the cured product. The amount of 1,2,3,6-tetrahydrophthalic anhydride relative to the entire acid monoanhydride (a4) is preferably in the range of 20 to 100 mol%, and in the range of 40 to 100 mol%. Is more preferable, but is not limited to these ranges.

In reacting the intermediate with the acid anhydride, a known method can be employed. For example, a reactive solution is obtained by adding an acid anhydride to a solvent solution of an intermediate, and further adding a thermal polymerization inhibitor and a catalyst as necessary, followed by stirring and mixing. By reacting this reactive solution at a temperature of preferably 60 to 150 ° C., particularly preferably 80 to 120 ° C., a carboxyl group-containing resin (A1) can be obtained by a conventional method. As the solvent, catalyst, and polymerization inhibitor, appropriate ones can be used, and the solvent, catalyst, and polymerization inhibitor used in the synthesis of the intermediate can be used as they are.

It is particularly preferable that the catalyst contains triphenylphosphine. That is, it is preferable to react an intermediate with an acid anhydride in the presence of triphenylphosphine. In this case, the reaction between the secondary hydroxyl group and the acid anhydride in the intermediate is particularly accelerated, and a reaction rate (conversion rate) of 90%, 95%, 97%, or almost 100% can be achieved. For this reason, the carboxyl group-containing resin (A1) having at least one of the structure (S4) and the structure (S5) is obtained in a high yield. In addition, the occurrence of ion migration in the layer containing the cured product of the dry film 13 is suppressed, and the insulation reliability of the same layer is further improved.

It is also preferable to react the intermediate and the acid anhydride under air bubbling. In this case, the developability by the alkaline aqueous solution of the dry film 13 improves especially by suppressing the excessive molecular weight increase of carboxyl group-containing resin (A1).

When the intermediate and the acid anhydride are reacted, the amount of the acid dianhydride (a3) is within the range of 0.02 to 0.4 mol with respect to 1 mol of the epoxy group of the epoxy compound (a1). It is preferable that it is in the range of 0.05 to 0.24 mol. Further, the amount of the acid monoanhydride (a4) is preferably in the range of 0.1 to 0.8 mol, based on 1 mol of the epoxy group of the epoxy compound (a1), and preferably 0.3 to 0.00. More preferably in the range of 7 moles. In this case, the carboxyl group-containing resin (A1) in which the acid value and the molecular weight are appropriately adjusted can be easily obtained. Moreover, the developability by the alkaline aqueous solution of the dry film 13 improves especially by suppressing the excessive molecular weight increase of carboxyl group-containing resin (A1).

The weight average molecular weight of the carboxyl group-containing resin (A1) is preferably in the range of 700 to 10,000. When the weight average molecular weight is 700 or more, the tackiness of the dry film 13 can be further suppressed, and the insulation reliability and plating resistance of the cured product can be further improved. Further, when the weight average molecular weight is 10,000 or less, the developability of the dry film 13 with an alkaline aqueous solution is particularly improved. The weight average molecular weight of the carboxyl group-containing resin (A1) is more preferably in the range of 900 to 8000, and particularly preferably in the range of 1000 to 5000.

Further, the solid content acid value of the carboxyl group-containing resin (A1) is preferably in the range of 60 to 140 mgKOH / g. In this case, the developability of the dry film 13 is particularly improved. The acid value is more preferably in the range of 80 to 135 mgKOH / g, and the acid value is more preferably in the range of 90 to 130 mgKOH / g.

The carboxyl group-containing resin (A) may contain a carboxyl group-containing resin other than the carboxyl group-containing resin (A1) (hereinafter also referred to as carboxyl group-containing resin (G)).

The carboxyl group-containing resin (G) is preferably contained in the reaction product of the polyol compound and the polyvalent carboxylic acid, but may contain a component not included in the reaction product of the polyol compound and the polyvalent carboxylic acid. .

The carboxyl group-containing resin (G) can contain, for example, a compound having a carboxyl group and not having photopolymerizability (hereinafter referred to as (G1) component). The component (G1) contains a polymer of an ethylenically unsaturated monomer including, for example, an ethylenically unsaturated compound having a carboxyl group. The ethylenically unsaturated compound having a carboxyl group can contain compounds such as acrylic acid, methacrylic acid, and ω-carboxy-polycaprolactone (n≈2) monoacrylate. The ethylenically unsaturated compound having a carboxyl group can also contain a reaction product of pentaerythritol triacrylate, pentaerythritol trimethacrylate and the like with a dibasic acid anhydride. Ethylenically unsaturated monomers include 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate, linear or branched aliphatic or alicyclic (provided that It may further contain an ethylenically unsaturated compound having no carboxyl group, such as (meth) acrylic acid ester (which may partially have an unsaturated bond in the ring).

The carboxyl group-containing resin (G) may contain a compound having a carboxyl group and an ethylenically unsaturated group (hereinafter referred to as (G2) component). The component (G2) includes, for example, an intermediate that is a reaction product of an epoxy compound (g1) having two or more epoxy groups in one molecule and an ethylenically unsaturated compound (g2), a polyvalent carboxylic acid, and its A resin (referred to as a first resin (g)) which is a reaction product with at least one compound (g3) selected from the group of anhydrides is contained. Since this intermediate is a polyol compound and compound (g3) is a polyvalent carboxylic acid, the first resin (g) is included in the reaction product of the polyol compound and the polyvalent carboxylic acid. For example, the first resin (g) is obtained by adding the compound (g3) to an intermediate obtained by reacting the epoxy group in the epoxy compound (g1) with the carboxyl group in the ethylenically unsaturated compound (g2). Can be obtained. The epoxy compound (g1) can contain an appropriate epoxy resin such as a cresol novolac epoxy resin or a phenol novolac epoxy resin. In particular, the epoxy compound (g1) preferably contains at least one compound selected from the group of biphenyl novolac type epoxy compounds and cresol novolac type epoxy compounds. The epoxy compound (g1) may contain only a biphenyl novolac type epoxy compound or may contain only a cresol novolac type epoxy compound. In this case, since an aromatic ring is contained in the main chain of the epoxy compound (g1), the cured product of the photosensitive resin composition is hardly corroded by the oxidizing agent. The epoxy compound (g1) may contain a polymer of the ethylenically unsaturated compound (h). The ethylenically unsaturated compound (h) contains a compound (h1) having an epoxy group such as glycidyl (meth) acrylate, or further has no epoxy group such as 2- (meth) acryloyloxyethyl phthalate. Contains compound (h2). The ethylenically unsaturated compound (g2) preferably contains at least one of acrylic acid and methacrylic acid. The compound (g3) contains at least one compound selected from the group consisting of polyvalent carboxylic acids such as phthalic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid, and anhydrides of these polyvalent carboxylic acids. .

The component (G2) is a resin (second resin) that is a reaction product of a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group and an ethylenically unsaturated compound having an epoxy group. (I)) may be contained. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group. The second resin (i) can be obtained by reacting an ethylenically unsaturated compound having an epoxy group with a part of the carboxyl group in the polymer. Examples of the ethylenically unsaturated compound having a carboxyl group include compounds such as acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≈2) monoacrylate, pentaerythritol triacrylate, and pentaerythritol trimethacrylate. Examples of the ethylenically unsaturated compound having no carboxyl group include 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate, linear or branched aliphatic or fatty acid It contains a compound such as a (meth) acrylic acid ester of a cyclic group (however, it may have a partially unsaturated bond in the ring). The ethylenically unsaturated compound having an epoxy group preferably contains glycidyl (meth) acrylate.

The carboxyl group-containing resin (A) contains, for example, only the carboxyl group-containing resin (A1) or the carboxyl group-containing resin (A1) and the carboxyl group-containing resin (G). The carboxyl group-containing resin (A) preferably contains 30% by mass or more of the carboxyl group-containing resin (A1), more preferably 50% by mass or more, and still more preferably 100% by mass. In this case, the heat resistance and insulation reliability of the cured product of the dry film 13 can be particularly improved. Further, the tackiness of the dry film 13 can be sufficiently reduced. Furthermore, the developability of the dry film 13 with an alkaline aqueous solution can be ensured. The carboxyl group-containing resin (A) may contain only the carboxyl group-containing resin (G).

The epoxy compound (B) contained in the dry film 13 will be specifically described.

The epoxy compound (B) can impart thermosetting properties to the dry film 13. The epoxy compound (B) preferably has at least two epoxy groups in one molecule. The epoxy compound (B) may be a poorly solvent-soluble epoxy compound or a general-purpose solvent-soluble epoxy compound.

The epoxy compound (B) is a phenol novolac type epoxy resin (specifically, product number EPICLON N-775 manufactured by DIC Corporation), a cresol novolak type epoxy resin (specific example, product number EPICLON N-695 manufactured by DIC Corporation), bisphenol A Novolac type epoxy resin (specifically, product number EPICLON N-865 manufactured by DIC Corporation), bisphenol A type epoxy resin (specifically, product number jER1001 manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resin (specifically, Mitsubishi Chemical Corporation) (Product number jER4004P manufactured by Co., Ltd.), bisphenol S type epoxy resin (specifically, product number EPICLON EXA-1514 manufactured by DIC Corporation), bisphenol AD type epoxy resin, biphenyl type epoxy resin ( As examples, product number YX4000 manufactured by Mitsubishi Chemical Co., Ltd., biphenyl novolac type epoxy resin (specific example, product number NC-3000 manufactured by Nippon Kayaku Co., Ltd.), hydrogenated bisphenol A type epoxy resin (specific example, Nippon Steel & Sumikin Chemical Co., Ltd.) Manufactured product number ST-4000D), naphthalene type epoxy resin (specific examples: product numbers EPICLON HP-4032, EPICLON HP-4700, EPICLON HP-4770 manufactured by DIC Corporation), hydroquinone type epoxy resin (specifically, Nippon Steel & Sumikin Chemical Co., Ltd.) Product number YDC-1312), tertiary butyl catechol type epoxy resin (specifically, product number EPICLON HP-820 manufactured by DIC Corporation), dicyclopentadiene type epoxy resin (specific example, product number EPICL manufactured by DIC) N HP-7200), adamantane type epoxy resin (specifically, product number ADAMANTATE X-E-201 manufactured by Idemitsu Kosan Co., Ltd.), bisphenol type epoxy resin (specific example, product number YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical), biphenyl ether Type epoxy resin (specifically, product number YSLV-80DE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), epoxy resin having a bisphenolfluorene skeleton (an epoxy resin having the structure shown in formula (7) as a specific example), rubbery core-shell polymer modified bisphenol Type A epoxy resin (specifically, product number MX-156 manufactured by Kaneka Corporation), rubbery core-shell polymer-modified bisphenol F type epoxy resin (specific example, product number MX-136 manufactured by Kaneka Corporation), and special bifunctional epoxy resin( As specific examples, product numbers YL7175-500 and YL7175-1000 manufactured by Mitsubishi Chemical Corporation; product numbers EPICLON TSR-960, EPICLON TER-601, EPICLON TSR-250-80BX, EPICLON 1650-75MPX, EPICLON EXA manufactured by DIC Corporation It is preferable to contain one or more components selected from the group consisting of -4850, EPICLON EXA-4816, EPICLON EXA-4822, and EPICLON EXA-9726; product number YSLV-120TE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.

In this embodiment, the epoxy compound (B) contains a crystalline epoxy resin (B1). A crystalline epoxy resin is an epoxy resin having a melting point. Therefore, particularly when the dry film 13 has photosensitivity, the developability of the dry film 13 can be improved. When the dry film 13 contains the carboxyl group-containing resin (A1), the developability is improved. Is remarkable. In this case, the developability of the dry film 13 with an alkaline aqueous solution can be improved, and the dry film 13 can be developed with an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide. This crystalline epoxy resin (B1) is, for example, 1,3,5-tris (2,3-epoxypropyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) trione, hydroquinone Type crystalline epoxy resin (specifically, product name YDC-1312 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), biphenyl type crystalline epoxy resin (specifically, product number YX-4000 manufactured by Mitsubishi Chemical Corporation), biphenyl ether type crystalline epoxy Resin (part number YSLV-80DE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), bisphenol type crystalline epoxy resin (part number YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), tetrakisphenol ethane type crystalline epoxy resin (specific example As specific examples, Nippon Kayaku Co., Ltd. product number GTR-1800), bisphenol fluore It may contain at least one component type crystalline epoxy resin is selected from the group consisting of (Examples epoxy resin having a structure represented by the formula (7)).

The epoxy compound (B) may contain a phosphorus-containing epoxy resin. In this case, the flame retardancy of the cured product of the dry film 13 is improved. Examples of phosphorus-containing epoxy resins include phosphoric acid-modified bisphenol F-type epoxy resins (specific examples of product numbers EPICLON EXA-9726 and EPICLON EXA-9710 manufactured by DIC Corporation), and product number Epototo FX-305 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Is mentioned.

The dry film 13 according to this embodiment preferably further contains an unsaturated compound (C) containing at least one polymerizable ethylenically unsaturated bond in one molecule, and a photopolymerization initiator (D). . In this case, photosensitivity can be imparted to the dry film 13. Moreover, the outstanding alkali developability can be provided in the non-exposed location of the dry film.

The unsaturated compound (C) and the photopolymerization initiator (D) will be specifically described.

The unsaturated compound (C) is, for example, a monofunctional (meth) acrylate such as 2-hydroxyethyl (meth) acrylate; and diethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) Acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ε-caprolactone modified pentaerythritol hexaacrylate, tricyclodecandi At least one compound selected from the group consisting of polyfunctional (meth) acrylates such as methanol di (meth) acrylate can be contained.

The unsaturated compound (C) preferably contains a trifunctional compound, that is, a compound having three unsaturated bonds in one molecule. In this case, the resolution when the dry film 13 is exposed and developed is improved, and the developability of the dry film 13 with an alkaline aqueous solution is particularly improved. Trifunctional compounds include, for example, trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethoxylated isocyanuric acid tri (meth) acrylate and ε-caprolactone modified It can contain at least one compound selected from the group consisting of tris- (2-acryloxyethyl) isocyanurate and ethoxylated glycerin tri (meth) acrylate.

It is also preferable that the unsaturated compound (C) contains a phosphorus-containing compound (phosphorus-containing unsaturated compound). In this case, the flame retardancy of the cured product of the dry film 13 is improved. Phosphorus-containing unsaturated compounds include, for example, 2-methacryloyloxyethyl acid phosphate (specific examples: product number light ester P-1M and light ester P-2M manufactured by Kyoeisha Chemical Co., Ltd.), 2-acryloyloxyethyl acid phosphate (Specific examples are product number light acrylate P-1A manufactured by Kyoeisha Chemical Co., Ltd.), diphenyl-2-methacryloyloxyethyl phosphate (specific examples are product number MR-260 manufactured by Daihachi Industry Co., Ltd.), and Showa Polymer Co., Ltd. HFA series (part number HFA-6003, which is an addition reaction product of dipentaerystol hexaacrylate and HCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) as a specific example, and HFA-6007, caprolactone Product No. HFA-3003, HFA-6127, etc., which are addition reaction products of modified dipentaerystol hexaacrylate and HCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) It can contain at least one compound selected from the group.

The unsaturated compound (C) may contain a prepolymer. The prepolymer is at least one selected from the group consisting of, for example, a prepolymer obtained by polymerizing a monomer having an ethylenically unsaturated bond and then adding an ethylenically unsaturated group, and oligo (meth) acrylate prepolymers These compounds can be contained. Oligo (meth) acrylate prepolymers include, for example, epoxy (meth) acrylate, polyester (meth) acrylate, urethane (meth) acrylate, alkyd resin (meth) acrylate, silicone resin (meth) acrylate, and spirane resin (meth) acrylate At least one component selected from the group consisting of:

The photopolymerization initiator (D) contains, for example, an acyl phosphine oxide photopolymerization initiator (D1). That is, the dry film 13 contains, for example, an acyl phosphine oxide photopolymerization initiator (D1). In this case, although the photosensitive resin composition contains the carboxyl group-containing resin (A1), high sensitivity to ultraviolet rays can be imparted to the photosensitive resin composition. Moreover, generation | occurrence | production of the ion migration in the layer containing the hardened | cured material of the photosensitive resin composition is suppressed, and the insulation reliability of the same layer improves further. Further, the acyl phosphine oxide photopolymerization initiator (D1) is unlikely to inhibit the electrical insulation of the cured product. For this reason, by curing the photosensitive resin composition by exposure, a cured product having excellent electrical insulation can be obtained. This cured product can be used as, for example, a solder resist layer, a plating resist layer, an etching resist layer, or an interlayer insulating layer. Is preferred.

Acylphosphine oxide photopolymerization initiators (D1) include monoacyl such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4,6-trimethylbenzoyl-ethyl-phenyl-phosphinate, etc. Phosphine oxide photopolymerization initiator, and 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-dimethoxybe Zoyl) -2,4,4-trimethylpentylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,4,6-trimethylbenzoyl) phenylphosphine Contains at least one component selected from the group consisting of bisacylphosphine oxide photopolymerization initiators such as fin oxide and (2,5,6-trimethylbenzoyl) -2,4,4-trimethylpentylphosphine oxide it can. In particular, the acylphosphine oxide photopolymerization initiator (D1) preferably contains 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and the acylphosphine oxide photopolymerization initiator (D1) is 2 , 4,6-Trimethylbenzoyl-diphenyl-phosphine oxide is also preferred.

The photopolymerization initiator (D) preferably contains a hydroxyketone photopolymerization initiator (D2) in addition to the acyl phosphine oxide photopolymerization initiator (D1). That is, it is preferable that the dry film 13 contains a hydroxyketone photopolymerization initiator (D2). In this case, higher sensitivity can be imparted to the dry film 13 as compared with the case where the hydroxyketone photopolymerization initiator (D2) is not contained. Thereby, when irradiating the film | membrane formed from the dry film 13 with an ultraviolet-ray and hardening it, it becomes possible to fully harden a film | membrane over the deep part from the surface. Examples of the hydroxyketone photopolymerization initiator (D2) include 1-hydroxy-cyclohexyl-phenyl-ketone, phenylglyoxyc acid methyl ester, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy -2-Methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane-1- On and 2-hydroxy-2-methyl-1-phenyl-propan-1-one.

The mass ratio of the acylphosphine oxide photopolymerization initiator (D1) to the hydroxyketone photopolymerization initiator (D2) is preferably in the range of 1: 0.01 to 1:10. In this case, the curability in the vicinity of the surface of the film formed from the dry film 13 and the curability in the deep portion can be improved in a balanced manner.

It is also preferred that the photopolymerization initiator (D) contains bis (diethylamino) benzophenone (D3). That is, the dry film 13 contains an acyl phosphine oxide photopolymerization initiator (D1) and bis (diethylamino) benzophenone (D3), or an acyl phosphine oxide photopolymerization initiator (D1), hydroxyketone light. It is also preferable to contain a polymerization initiator (D2) and bis (diethylamino) benzophenone (D3). In this case, when the film formed from the dry film 13 is partially exposed and then developed, the resolution is particularly improved by suppressing the curing of the unexposed part. For this reason, a very fine pattern can be formed with the cured product of the dry film 13. In particular, when an interlayer insulating layer of a multilayer printed wiring board is produced from the dry film 13 and a small-diameter hole for a through hole is provided in the interlayer insulating layer by a photolithography method (see FIGS. 2A to F), the small-diameter hole is formed. Precise and easy to form.

The amount of bis (diethylamino) benzophenone (D3) relative to the acylphosphine oxide photopolymerization initiator (D1) is preferably in the range of 0.5 to 20% by mass. When the amount of bis (diethylamino) benzophenone (D3) with respect to the acylphosphine oxide photopolymerization initiator (D1) is 0.5% by mass or more, the resolution is particularly high. When the bis (diethylamino) benzophenone (D3) is 20% by mass or less with respect to the acylphosphine oxide photopolymerization initiator (D1), the electrical insulation of the cured product of the dry film 13 is bis (diethylamino) benzophenone (D3). ) Is difficult to inhibit.

The dry film 13 according to this embodiment may further contain a known photopolymerization accelerator, sensitizer, and the like. For example, the dry film 13 includes benzoin and its alkyl ethers; acetophenones such as acetophenone and benzyldimethyl ketal; anthraquinones such as 2-methylanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2-isopropylthioxanthone. Thioxanthones such as 4-isopropylthioxanthone and 2,4-diisopropylthioxanthone; benzophenones such as benzophenone and 4-benzoyl-4′-methyldiphenyl sulfide; xanthones such as 2,4-diisopropylxanthone; and 2-hydroxy- Α-hydroxyketones such as 2-methyl-1-phenyl-propan-1-one; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propano It can contain at least one component selected from the group consisting of compounds containing a nitrogen atom and the like. The dry film 13 is formed with a photopolymerization initiator (D) and known photopolymerization such as tertiary amines such as p-dimethylbenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ester and 2-dimethylaminoethylbenzoate. You may contain a promoter, a sensitizer, etc. If necessary, the dry film 13 may contain at least one of a photopolymerization initiator for visible light exposure and a photopolymerization initiator for near-infrared exposure. The dry film 13 may contain a photopolymerization initiator (D) and a coumarin derivative such as 7-diethylamino-4-methylcoumarin, which is a sensitizer for laser exposure, a carbocyanine dye system, a xanthene dye system, and the like. Good.

The dry film 13 according to this embodiment preferably further contains a surfactant (E). In this case, the generation of bubbles and the like when forming the dry film 13 is suppressed, and the uniform dry film 13 is easily formed.

The surfactant (E) particularly preferably has a fluorine atom. In this case, since the surface tension of the resin composition can be greatly reduced, the dispersibility of the components of the dry film 13 is improved, and the dry film 13 with higher uniformity can be easily formed. Examples of the surfactant (E) are, for example, DIC's product numbers Mega-Fuck F-470, Mega-Fuck F-477, Mega-Fuck F-553, Mega-Fuck F-555, Mega-Fuck F-556, Mega-Fuck F-557 Megafuck F-559, Megafuck F-562, Megafuck F-565, Megafuck F-567, Megafuck F-568, Megafuck F-571, Megafuck R-40, and Megafuck R-94; Fluorad FC4430 and Fluorard FC-4432 manufactured by 3M Japan KK; Surflon S-241, Surflon S-242, Surflon S-243, Surflon S-420, Surflon S-611, Surflon S- manufactured by AGC Seimi Chemical Co., Ltd. 651, and Surflon S-386; and OMN VA manufactured by PF636, PF6320, PF656, and a PF6520.

The dry film 13 according to this embodiment preferably further contains melamine (F). In this case, good adhesion can be imparted to the dry film 13, and the adhesion between the cured product of the dry film 13 and a metal such as copper is increased. For this reason, the dry film 13 is particularly suitable as an insulating material for a printed wiring board. Further, the plating resistance of the cured product of the dry film 13, that is, the whitening resistance during the electroless nickel / gold plating process is improved.

The amount of the carboxyl group-containing resin relative to the dry film 13 is preferably in the range of 5 to 85% by mass, more preferably in the range of 10 to 75% by mass, and in the range of 30 to 60% by mass. Further preferred.

With respect to the amount of the epoxy compound (B), the total of the equivalents of epoxy groups contained in the epoxy compound (B) is 0.7 to 2.5 with respect to 1 equivalent of carboxyl groups contained in the carboxyl group-containing resin (A). Is preferably within the range of 0.7 to 2.3, more preferably within the range of 0.7 to 2.0. Further, the crystalline epoxy resin (B1) is preferably in the range of 10 to 100% by mass, more preferably in the range of 30 to 100% by mass with respect to the epoxy compound (B), and 35 to More preferably, it is in the range of 100% by mass. In this case, the thermosetting reaction of the carboxyl group-containing resin is suppressed in the process before the thermosetting of the dry film 13, and the developability can be improved.

The amount of the unsaturated compound (C) relative to the carboxyl group-containing resin (A) is preferably in the range of 10 to 50% by mass, more preferably in the range of 21 to 40% by mass, and 23 to 36%. If it is in the range of mass%, it is still more preferable.

The amount of the photopolymerization initiator (D) relative to the carboxyl group-containing resin (A) is preferably in the range of 0.1 to 30% by mass, and more preferably in the range of 1 to 25% by mass.

When the dry film contains the surfactant (E), the amount of the surfactant (E) relative to the carboxyl group-containing resin (A) is preferably in the range of 0.005 to 5% by mass. The content is more preferably in the range of 0.01 to 1% by mass, and still more preferably in the range of 0.02 to 0.5% by mass.

When the dry film contains melamine (F), the amount of melamine (F) with respect to the carboxyl group-containing resin (A) is preferably in the range of 0.1 to 10% by mass, preferably 0.5 to 5%. If it is in the range of mass%, it is still more preferable.

As long as the effects of the present embodiment are not hindered, the dry film 13 may further contain components other than the above components.

For example, the dry film 13 may contain an inorganic filler. In this case, the curing shrinkage of the film formed from the dry film 13 is reduced. The inorganic filler can contain at least one material selected from the group consisting of, for example, barium sulfate, crystalline silica, nano silica, carbon nanotube, talc, bentonite, aluminum hydroxide, magnesium hydroxide, and titanium oxide. The dry film 13 and its cured product may be whitened by including a white material such as titanium oxide or zinc oxide in the inorganic filler. The ratio of the inorganic filler in the dry film 13 is appropriately set, but is preferably in the range of 0 to 300% by mass with respect to the carboxyl group-containing resin (A).

Dry film 13 is made of tolylene diisocyanate, morpholine diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate blocked isocyanates blocked with caprolactam, oxime, malonate, etc .; melamine resin, n-butylated melamine resin, isobutyl Amino resins such as melamine resin, butylated urea resin, butylated melamine urea cocondensation resin, benzoguanamine cocondensation resin; various other thermosetting resins; ultraviolet curable epoxy (meth) acrylate; bisphenol A type, phenol Resin obtained by adding (meth) acrylic acid to epoxy resin such as novolak type, cresol novolak type, alicyclic type; and diallyl phthalate resin, phenoxy resin, urethane resin, fluorine resin It may contain at least one resin selected from the group consisting of a polymer compound and the like.

The dry film 13 may contain a curing agent for curing the epoxy compound. Examples of the curing agent include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- (2- Imidazole derivatives such as cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, 4 Amine compounds such as methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic hydrazide and sebacic acid hydrazide; phosphorus compounds such as triphenylphosphine; acid anhydrides; phenols; mercaptans; Lewis acid amine complexes; Oni It can contain at least one component selected from the group consisting of unsalted. Commercially available products of these components include, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Co., Ltd., U-CAT3503N, U -CAT3502T (all are trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof).

The dry film 13 may contain an adhesion promoter other than melamine (F). Examples of the adhesion-imparting agent include guanamine, acetoguanamine, benzoguanamine, and 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S-triazine, 2-vinyl-4. , 6-diamino-S-triazine / isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct, and the like.

Dry film 13 is a curing accelerator; a colorant; a copolymer such as silicone and acrylate; a leveling agent; an adhesion-imparting agent such as a silane coupling agent; a thixotropic agent; a polymerization inhibitor; an antihalation agent; It may contain at least one component selected from the group consisting of foaming agents; antioxidants; and polymer dispersants.

The content of the amine compound in the dry film 13 is preferably as small as possible. In this case, the electrical insulation of the layer made of a cured product of the resin composition is unlikely to be impaired. In particular, the amine compound is preferably 6% by mass or less, more preferably 4% by mass or less, based on the carboxyl group-containing resin (A).

An example of a method for manufacturing the dry film laminate 15 according to the present embodiment will be described.

First, a resin composition containing the components of the dry film 13 is prepared. The resin composition may contain an organic solvent. The organic solvent is used for the purpose of liquefaction or varnishing of the resin composition, viscosity adjustment, application property adjustment, film formation property adjustment, and the like.

Organic solvents include, for example, linear, branched, secondary or polyhydric alcohols such as ethanol, propyl alcohol, isopropyl alcohol, hexanol and ethylene glycol; ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene Petroleum aromatic mixed solvents such as Swazol series (manufactured by Maruzen Petrochemical Co., Ltd.), Solvesso series (manufactured by Exxon Chemical Co., Ltd.), cellosolves such as cellosolve and butylcellosolve, and carbitols such as carbitol and butylcarbitol Tolls; propylene glycol alkyl ethers such as propylene glycol methyl ether; polypropylene glycol alkyl ethers such as dipropylene glycol methyl ether; ethyl acetate, butyl acetate, cellosolve acetate, cal Acetic acid esters such as tall acetate; as well as containing at least one compound selected from the group consisting of dialkyl glycol ethers.

When the organic solvent is contained, the amount of the organic solvent is determined so that the organic solvent is volatilized and disappears quickly when the coating film formed from the resin composition is dried, that is, the organic solvent does not remain in the dry film 13. It is preferable to be adjusted. In particular, the amount of the organic solvent relative to the entire resin composition is preferably in the range of 0 to 99.5% by mass, and more preferably in the range of 15 to 60% by mass. In addition, since the suitable ratio of an organic solvent changes with application methods etc., it is preferable that a ratio is suitably adjusted according to the application method.

The resin composition raw materials as described above are blended, and the resin composition can be prepared by kneading by a known kneading method using, for example, a three-roll, ball mill, sand mill or the like. When the raw material of the resin composition contains a liquid component, a low viscosity component, etc., the portion of the raw material excluding the liquid component, the low viscosity component, etc. is first kneaded, and the resulting mixture is mixed with a liquid component. You may prepare a resin composition by adding and mixing a component, a component with a low viscosity, etc.

In consideration of storage stability and the like, the first agent may be prepared by mixing a part of the components of the resin composition, and the second agent may be prepared by mixing the rest of the components. That is, the resin composition may include a first agent and a second agent. In this case, for example, among the components of the resin composition, the first agent is prepared by mixing and dispersing the unsaturated compound (C), a part of the organic solvent, and the thermosetting component in advance, You may prepare a 2nd agent by mixing and disperse | distributing the remainder among components. In this case, the required amount of the first agent and the second agent are mixed in a timely manner to prepare a mixed solution, and the dry film 13 can be obtained from this mixed solution.

The dry film 13 can be formed on the base film 12 by applying the resin composition on the polyethylene terephthalate film as the base film 12 and then drying. Thereby, the member provided with the base film 12 which supports the dry film 13 and the dry film 13 is obtained. The coating method of the resin composition is selected from the group consisting of known methods such as dipping, spraying, spin coating, roll coating, curtain coating, and screen printing. The drying temperature of the resin composition is, for example, in the range of 40 to 150 ° C. in order to volatilize the organic solvent contained in the resin composition.

Subsequently, a dry film laminate 15 is obtained by press-bonding a stretched polypropylene film as the cover film 14 to the dry film 13. The dry film laminate 15 is stored in a roll shape, for example. As described above, the dry film laminated body 15 in which the epoxy resin or the like hardly precipitates even when stored and the cover film 14 is easily peeled off from the dry film 13 is formed.

The dry film 13 according to this embodiment is suitable for an electrically insulating material for a printed wiring board. In particular, the dry film 13 is suitable for a material of an electrically insulating layer such as a solder resist layer, a plating resist layer, an etching resist layer, or an interlayer insulating layer.

The dry film 13 according to this embodiment preferably has such a property that the film made of the dry film 13 can be developed with an aqueous sodium carbonate solution when the thickness of the film made of the dry film 13 is 25 μm. In this case, since a sufficiently thick electrically insulating layer can be produced by a photolithography method, the dry film 13 is widely used for producing an interlayer insulating layer, a solder resist layer, etc. in a printed wiring board. Applicable. Of course, it is also possible to produce an electrically insulating layer having a thickness of less than 25 μm from the dry film 13.

Whether the film can be developed with an aqueous sodium carbonate solution can be confirmed by the following method. A wet coating film is formed by applying the resin composition on an appropriate substrate, and the wet coating film is heated at 80 ° C. for 40 minutes to form a coating film made of the dry film 13 having a thickness of 25 μm. The film is exposed by irradiating the film with ultraviolet rays under the condition of 500 mJ / cm ² through the negative mask in a state in which a negative mask having an exposed part that transmits ultraviolet rays and a non-exposed part that blocks ultraviolet rays is directly applied to the film. After the exposure, a 1% Na ₂ CO ₃ aqueous solution at 30 ° C. is jetted for 90 seconds at a jetting pressure of 0.2 MPa, and then pure water is jetted for 90 seconds at a jetting pressure of 0.2 MPa. As a result of observing the film after this treatment, it can be determined that the film having a thickness of 25 μm can be developed with an aqueous sodium carbonate solution when a portion corresponding to the non-exposed portion of the film is removed and no residue is observed.

Hereinafter, an example of a method of manufacturing a printed wiring board including an interlayer insulating layer formed from the dry film according to the present embodiment will be described with reference to FIGS. 2A to 2F. In this method, a through hole is formed in the interlayer insulating layer by photolithography.

First, a core material 1 is prepared as shown in FIG. 2A. The core material 1 includes, for example, at least one insulating layer 2 and at least one conductor wiring 3. The conductor wiring 3 provided on one surface of the core material 1 is hereinafter referred to as a first conductor wiring 3.

The cover film 14 in the dry film laminate 15 is peeled from the dry film 13. In this embodiment, the cover film 14 can be easily peeled from the dry film 13. The dry film 13 is stacked on the core material 1.

Subsequently, after applying pressure to the dry film 13 and the core material 1, the base film 12 is peeled from the dry film 13 as shown in FIG. 2B, so that the dry film 13 is transferred from the base film 12 onto the core material 1. Transcript. Thereby, as shown in FIG. 2C, the coating 4 made of the dry film 13 is provided on the core material 1.

The film 4 is partially photocured by exposing the film 4 as shown in FIG. 2D. For this purpose, for example, after applying a negative mask to the film 4, the film 4 is irradiated with ultraviolet rays through the negative mask. The negative mask includes an exposure part that transmits ultraviolet light and a non-exposure part that blocks ultraviolet light, and the non-exposure part is provided at a position that matches the position of the through hole 10. The negative mask is a photo tool such as a mask film or a dry plate. The ultraviolet light source is 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, and metal halide lamps, for example.

The exposure method may be a method other than a method using a negative mask. For example, the film 4 may be exposed by a direct drawing method in which ultraviolet rays emitted from a light source are irradiated only on a portion to be exposed on the film 4. The light source applied to the direct drawing method is, for example, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, g-line (436 nm), h-line (405 nm), i-line (365 nm), and g-line, h-line, and i-line. It is selected from the group consisting of two or more kinds of combinations.

In the dry film method, the film 4 is exposed by irradiating the film 4 made of the dry film 13 through the base film 12 without peeling off the base film 12 after the dry film 13 is stacked on the core material 1. Then, the base film 12 may be peeled off from the coating 4 before the development processing.

Subsequently, the coating 4 is developed to remove the unexposed portion 5 of the coating 4 shown in FIG. 2D, whereby the hole 6 is formed at the position where the through hole 10 is formed as shown in FIG. 2E. Is provided. In the development process, an appropriate developer according to the composition of the dry film 13 can be used. The developer is, for example, an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide, or an organic amine. More specifically, the alkaline aqueous solution is, for example, sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate, sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethyl ammonium hydroxide and water. It contains at least one component selected from the group consisting of lithium oxide. The solvent in the alkaline aqueous solution may be water alone or a mixture of water and a hydrophilic organic solvent such as lower alcohols. The organic amine contains, for example, at least one component selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine.

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

Subsequently, the coating 4 is cured by heating. The heating conditions are, for example, a heating temperature range of 120 to 200 ° C. and a heating time range of 30 to 120 minutes. When the film 4 is thermally cured in this manner, the performance of the interlayer insulating layer 7 such as strength, hardness, and chemical resistance is improved.

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

Thus, the interlayer insulating layer 7 made of a cured product of the dry film 13 is provided on the core material 1. The second conductor wiring 8 and the hole plating 9 can be provided on the interlayer insulating layer 7 by a known method such as an additive method. Thus, as shown in FIG. 2F, the first conductor wiring 3, the second conductor wiring 8, the interlayer insulating layer 7 interposed between the first conductor wiring 3 and the second conductor wiring 8, and the first A printed wiring board 11 having a through hole 10 for electrically connecting the first conductor wiring 3 and the second conductor wiring 8 is obtained. In FIG. 2F, the hole plating 9 has a cylindrical shape that covers the inner surface of the hole 6, but the entire inner side of the hole 6 may be filled with the hole plating 9.

Further, before the hole plating 9 as shown in FIG. 2F 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 manner, the adhesion between the core material 1 and the hole plating 9 can be improved by roughening a part of the outer surface of the interlayer insulating layer 7 and the inner side surface of the hole 6.

An example of a method for producing a printed wiring board having a solder resist layer formed from the dry film 13 according to the present embodiment will be described.

First, prepare the core material. The core material includes, for example, at least one insulating layer and at least one conductor wiring. A film is formed from the dry film 13 on the surface on which the conductor wiring of the core material is provided. As a method for forming the film, the same method as that for forming the interlayer insulating layer can be employed. The film is partially cured by exposure. The exposure method can be the same as the method for forming the interlayer insulating layer. Subsequently, the film is subjected to a development process to remove the unexposed part of the film, whereby the exposed part of the film remains on the core material. Subsequently, the coating on the core material is cured by heating. The developing method and the heating method can be the same as the method for forming the interlayer insulating layer. If necessary, the film may be further irradiated with ultraviolet rays before or after heating. In this case, photocuring of the film can be further advanced.

Thus, a solder resist layer made of a cured product of the dry film 13 is provided on the core material. Thereby, a printed wiring board provided with the core material provided with an insulating layer and the conductor wiring on it, and the soldering resist layer which partially covers the surface in which the conductor wiring in the core material is provided is obtained.

Hereinafter, the present invention will be specifically described by way of examples.

(1) Synthesis of carboxyl group-containing resin In a four-necked flask equipped with a reflux condenser, a thermometer, an air blowing tube, and a stirrer, the raw material components shown in the “First Reaction” column of Table 1 were added, These were stirred under air bubbling to prepare a mixture. While stirring this mixture in a four-necked flask under air bubbling, the mixture was heated at the reaction temperature and reaction time indicated in the “Reaction Conditions” column of the “First Reaction” column. This prepared an intermediate solution.

Subsequently, the raw material components shown in the “second reaction” column of Table 1 are added to the intermediate solution in the four-necked flask, and the “second reaction” is performed while stirring the solution in the four-necked flask under air bubbling. The column was heated at the reaction temperature and reaction time shown in the column “Reaction Conditions (1)”. Subsequently, with the exception of Synthesis Example A-6, while stirring the solution in the four-necked flask under air bubbling, the reaction temperature and reaction time shown in the “Reaction Conditions (2)” column of the “Second Reaction” column were used. Heated. This obtained a 65 mass% solution of carboxyl group-containing resin. The weight average molecular weight and acid value of the carboxyl group-containing resin are as shown in Table 1. The molar ratio between the components is also shown in Table 1.

In addition, the detail of the component shown in the (a1) column of Table 1 is as follows.
Epoxy compound 1: a bisphenolfluorene type epoxy compound represented by the formula (7) and having an epoxy equivalent of 250 g / eq, wherein R ₁ to R ₈ in the formula (7) are all hydrogen.
Epoxy compound 2: epoxy represented by the formula (7), wherein R ₁ and R ₅ in the formula (7) are all methyl groups, and R ₂ to R ₄ and R ₆ to R ₈ are all hydrogen Bisphenolfluorene type epoxy compound having an equivalent weight of 279 g / eq.

(2) Preparation of Resin Composition A part of the components shown in the “Composition” column of Tables 2 to 3 below was kneaded with three rolls. Next, the kneaded product was transferred into a flask, and all the components shown in Tables 2 to 3 below were stirred and mixed to obtain resin compositions of Examples and Comparative Examples. Details of the components shown in Tables 2 to 3 are as follows.
Crystalline epoxy resin (YX4000): Biphenyl type crystalline epoxy resin, manufactured by Mitsubishi Chemical Corporation, product name YX-4000, melting point 105 ° C., epoxy equivalent 187 g / eq.
Crystalline epoxy resin (YDC1312): Hydroquinone type crystalline epoxy resin, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., product name YDC-1312, melting point 138 to 145 ° C., epoxy equivalent 176 g / eq.
Amorphous epoxy resin solution (EXA4816): long chain carbon chain-containing bisphenol A type epoxy resin, manufactured by DIC, product number EPICLON EXA-4816, liquid resin, epoxy equivalent 410 g / eq with diethylene glycol monoethyl ether acetate at 90% solid content (Epoxy equivalent in terms of solid content of 90% is 455.56 g / eq).
Amorphous epoxy resin solution (N-695): Cresol novolac type epoxy resin, manufactured by DIC, product number EPICLON N-695, softening point 90-100 ° C., epoxy equivalent 214 g / eq at a solid content of 75%, diethylene glycol monoethyl ether A solution dissolved in acetate (epoxy equivalent of 75% solid content is 285.33 g / eq).
Unsaturated compound (TMPTA): trimethylolpropane triacrylate.
Unsaturated compound (DPHA): dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd., product number KAYARAD DPHA.
Photopolymerization initiator (TPO): 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, manufactured by BASF, product number Irgacure TPO.
Photopolymerization initiator (IC184): 1-hydroxy-cyclohexyl-phenyl-ketone, manufactured by BASF, product number Irgacure 184
Photopolymerization initiator (EAB): 4,4′-bis (diethylamino) benzophenone.
Surfactant (F-477): manufactured by DIC, product number MegaFuck F-477
Surfactant (F-556): DIC, product number MegaFuck F-556
Melamine: manufactured by Nissan Chemical Industries, Ltd., fine melamine; dispersed in the photosensitive resin composition with an average particle size of 8 μm.
Antioxidant: A hindered phenol antioxidant, manufactured by BASF, product number IRGANOX 1010.
Blue pigment: phthalocyanine blue.
Yellow pigment: 1,1 ′-[(6-phenyl-1,3,5-triazine-2,4-diyl) bis (imino)] bis (9,10-anthracenedione).
Barium sulfate: manufactured by Sakai Chemical Industry Co., Ltd., product number Variace B31.
-Talc: Product number SG-2000, manufactured by Nippon Talc.
Bentonite: manufactured by Leox, part number Benton SD-2.
-Rheology control agent: manufactured by Big Chemy Japan, product number BYK-430.
Solvent: methyl ethyl ketone.

[Examples 1 to 13 and Comparative Examples 1 to 4]
[Production of dry film and dry film laminate]
The resin composition is applied on a polyethylene terephthalate film, which is a base film, with an applicator, and then dried by heating at 80 ° C. for 30 minutes and then at 110 ° C. for 5 minutes to obtain a dry film having a thickness of 25 μm. Formed.

Subsequently, the top of the dry film was covered with a biaxially stretched polypropylene film as a cover film, and the cover film was pressure-bonded through a roll at 40 ° C. to obtain a dry film laminate.

[Production of test pieces]
A glass epoxy copper clad laminate (FR-4 type) provided with a 35 μm thick copper foil was prepared. A comb-like electrode having a line width / space width of 100 μm / 100 μm was formed as a conductor wiring on this glass epoxy copper clad laminate by a subtractive method, thereby obtaining a printed wiring board. The conductor wiring was roughened by dissolving and removing the surface portion of the printed wiring board having a thickness of about 1 μm with a product number CZ-8100 manufactured by MEC Co., Ltd.

Subsequently, after the cover film of the dry film laminate was peeled off, the dry film was heat-laminated on the printed wiring board. The heating lamination was performed with a vacuum laminator under conditions of 0.5 MPa, 80 ° C., and 1 minute. Thereby, a film having a thickness of 25 μm was formed on the printed wiring board.

With the base film overlapped with the coating, the negative mask including a circular non-exposed portion with a diameter of 80 μm and the base film are directly applied to the coating through the negative mask from the polyethylene terephthalate film of the base film. Ultraviolet rays were irradiated under the condition of 400 mJ / cm ² .

Subsequently, the base film was peeled off from the film, and a 1% Na ₂ CO ₃ aqueous solution was sprayed onto the film for 90 seconds at 30 ° C. and a pressure of 0.2 MPa.

Subsequently, the film was cleaned by spraying pure water with a spray pressure of 0.2 MPa for 90 seconds. Thereby, the part which was not exposed in a film | membrane was removed, and the hole was formed.

Subsequently, after heating the film at 160 ° C. for 60 minutes, the film was further irradiated with ultraviolet rays under the condition of 1000 mJ / cm ² .

Thereby, a layer made of a cured product of a dry film was formed on the printed wiring board. As a result, a test piece was obtained.

[Evaluation test]
An evaluation test was performed for each example and comparative example. However, in Comparative Example 2, since the dry film adhered to the cover film when the cover film was peeled off, the evaluations (2) to (6) were not performed. In Comparative Examples 3 and 4, since development residues were generated in the development processing step, evaluations (2) to (6) were not performed.

(1) Developability About each Example and the comparative example, the film | membrane with a thickness of 25 micrometers which consists of a dry film was formed on the printed wiring board by the same method as the case where a test piece is produced. This film was developed without exposure. In the development process, a 1% Na ₂ CO ₃ aqueous solution at 30 ° C. was sprayed for 90 seconds at a spray pressure of 0.2 MPa, and then pure water was sprayed for 90 seconds at a spray pressure of 0.2 MPa. The printed wiring board after the treatment was observed, and the result was evaluated as follows.
A: All the films are removed.
B: A part of the film remained on the printed wiring board.

(2) Resolution The hole formed in the layer which consists of hardened | cured material in the test piece of each Example and a comparative example was observed, and the result was evaluated as follows.
A: The diameter of the bottom of the hole is 70 μm or more.
B: The diameter of the bottom of the hole is less than 70 μm.
C: A clear hole is not formed.

(3) Plating resistance After forming a nickel plating layer using a commercially available electroless nickel plating bath on the layer made of the cured product in the test pieces of the examples and comparative examples, a commercially available electroless gold plating is performed. A gold plating layer was formed using a bath. Thereby, the metal layer which consists of a nickel plating layer and a gold plating layer was formed on the layer which consists of hardened | cured material. The layer made of the cured product and the metal layer were visually observed. Moreover, the cellophane adhesive tape peeling test was done with respect to the layer which consists of hardened | cured materials, and a metal layer. The results were evaluated as follows.
A: No abnormality was observed in the appearance of the layer made of the cured product and the metal layer, and the layer made of the cured product was not peeled by the cellophane adhesive tape peeling test.
B: Although discoloration was recognized in the layer which consists of hardened | cured materials, peeling of the layer which consists of hardened | cured materials by the cellophane adhesive tape peeling test did not arise.
C: Lifting of the layer made of the cured product was observed, and peeling of the layer made of the cured product by the cellophane adhesive tape peeling test occurred.

(4) Insulation between lines While applying a bias voltage of DC 30 V to the conductor wiring (comb electrode) in the test piece of each example and comparative example, the test piece was placed at 121 ° C. and 97% R.D. H. The test environment was exposed for 120 hours. The electrical resistance value between the comb-type electrodes of the cured product layer in this test environment was constantly measured, and the result was evaluated according to the following evaluation criteria.
A: The electric resistance value was constantly maintained at 10 ⁶ Ω or more until 120 hours passed from the start of the test.
B: The electric resistance value was constantly maintained at 10 ⁶ Ω or more until 100 hours passed from the start of the test, but the electric resistance value was less than 10 ⁶ Ω before 120 hours passed from the start of the test.
C: electrical resistance was less than 10 ⁶ Omega before lapse of 100 hours from the start the test.

(5) Interlayer insulation The conductive tape was affixed on the layer which consists of hardened | cured material in the test piece of each Example and a comparative example. While applying a bias voltage of 100 V DC to this conductive tape, the test piece was placed at 130 ° C. and 85% R.D. H. The test environment was exposed for 60 hours. The electrical resistance value between the conductive wiring of the layer made of the cured product and the conductive tape in this test environment was constantly measured, and the result was evaluated according to the following evaluation criteria.
A: Between the start of the study until after 50 hours, the electric resistance value was always maintained above 10 ⁶ Omega.
B: The electric resistance value was always maintained at 10 ⁶ Ω or more until 35 hours passed from the start of the test, but the electric resistance value became less than 10 ⁶ Ω before 50 hours passed from the start of the test.
C: The electric resistance value was less than 10 ⁶ Ω before 35 hours passed from the start of the test.

(6) PCT (pressure cooker test)
The test pieces of each Example and Comparative Example were 121 ° C. and 100% R.D. H. After being allowed to stand for 80 hours in this environment, the appearance of the cured layer was evaluated according to the following evaluation criteria.
A: No abnormality was found in the layer made of the cured product.
B: Discoloration was observed in the layer made of the cured product.
C: A large discoloration was observed in the layer made of the cured product, and partial swelling occurred.

(7) Coating film surface state After coating the resin composition in each Example and Comparative Example on a film made of polyethylene terephthalate with an applicator, the film after heating and drying at 95 ° C. for 25 minutes was observed. Evaluation was performed according to the following evaluation criteria.
A: A uniform surface state.
B: There is a portion where the film thickness is slightly uneven.
C: A pinhole has occurred.

(8) Dry film stability 1
In each example and comparative example, when the dry film laminate was stored at 20 ° C. for 2 weeks immediately after the production, the presence or absence of acicular crystal-like foreign matters in the dry film laminate was evaluated according to the following evaluation criteria. evaluated.
A: No acicular crystal-like foreign matter was observed.
B: Needle-like crystal-like foreign matters were observed on the inner surface of the cover film (the surface in contact with the dry film).
C: Acicular crystal-like foreign matters were observed on the outer surface of the cover film (the surface opposite to the surface in contact with the dry film).

The results are shown in the column of “Dry Film Stability 1 (OPP)” in Tables 2 and 3. Moreover, the evaluation test was similarly performed about the case where it changed into the polyethylene terephthalate (PET) film and the case where it changed into the polyethylene (PE) film for the comparative evaluation. The results are shown together in the columns of “Dry Film Stability 1 (PET)” and “Dry Film Stability 1 (PE)” in Table 2 and Table 3, respectively.

(9) Dry film stability 2
In each of the examples and comparative examples, after producing a laminate of dry films, when wound into a roll and stored at 20 ° C. for 2 weeks, the occurrence of acicular crystal-like foreign matters in the dry film laminate was determined. Evaluation was made according to the following evaluation criteria.
A: No acicular crystal-like foreign matter was observed.
B: Needle-like crystal-like foreign matters were observed on the inner surface of the base film (the surface in contact with the dry film) or the inner surface of the cover film.
C: Needle-like crystal-like foreign matters were observed on the outer surface of the base film (the surface opposite to the surface in contact with the dry film) or the outer surface of the cover film.

The results are shown in the column of “Dry Film Stability 2 (OPP)” in Tables 2 and 3. Moreover, the evaluation test was similarly performed about the case where it changed into the polyethylene terephthalate (PET) film and the case where it changed into the polyethylene (PE) film for the comparative evaluation. The results are shown together in the columns of “Dry Film Stability 2 (PET)” and “Dry Film Stability 2 (PE)” in Table 2 and Table 3, respectively.

(10) Cover film peelability In each Example and Comparative Example, the peelability of the cover film was evaluated according to the following evaluation criteria.
A: The cover film was easily peeled off, and no dry film was adhered to the cover film.
B: The cover film can be easily peeled off, but the dry film was adhered to the cover film.
C: It was difficult to peel off the cover film, and a dry film was adhered to the cover film.

This result is shown in the column of “Cover film peelability (OPP)” in Tables 2 and 3. Moreover, the evaluation test was similarly performed about the case where it changed into the polyethylene terephthalate (PET) film and the case where it changed into the polyethylene (PE) film for the comparative evaluation. The results are shown together in the columns “Cover film peelability (PET)” and “Cover film peelability (PE)” in Table 2 and Table 3, respectively.

The evaluation results for the above evaluation tests are shown in Tables 2 and 3. In Tables 2 and 3, “crystalline epoxy E / A” is the equivalent of the epoxy group contained in the crystalline epoxy resin (B1) relative to the carboxyl group-containing resin (A), “amorphous epoxy E / A”. Is the equivalent of the epoxy group contained in the amorphous epoxy resin with respect to 1 equivalent of the carboxyl group contained in the carboxyl group-containing resin (A). Is equivalent to the epoxy group contained in.

According to the above results, when the cover film was a polyethylene film and the resin composition contained a crystalline epoxy resin, needle-like crystal-like foreign matters were observed on the outer surface of the cover film. As a result of analysis, the acicular crystal-like foreign material was a crystalline epoxy resin. From this phenomenon, it is considered that the crystalline epoxy resin dissolved in the dry film permeates the polyethylene film and cannot be maintained in the dissolved state and crystallizes. Moreover, when preserve | saved in the state of roll winding, the acicular crystal-like foreign material was observed in the part which contact | connects the cover film of the outer surface of a base film. This is because the crystalline epoxy resin dissolved in the dry film passes through the polyethylene film as the cover film and then adheres to the outer surface of the base film made of polyethylene terephthalate film, which has higher adhesion than the polyethylene film, and crystallizes. It is thought that.

If the cover film is a polyethylene terephthalate film, sticking of the dry film to the cover film occurs. This is presumably because the dry film before curing has a relatively strong adhesion to the polyethylene terephthalate film and uses the same material as the base film.

On the other hand, when the dry film contains a crystalline epoxy resin and the base film of the dry film laminate is a polyethylene terephthalate film, the cover film is a stretched polypropylene film to prevent the transmission or precipitation of the crystalline epoxy resin. And good stability can be obtained. Moreover, when peeling a cover film, it becomes possible to peel easily, without a dry film sticking.

The dry film of the first aspect includes a base film 12, a dry film 13, and a cover film 14, which are laminated in this order. The base film 12 is a polyethylene terephthalate film, and the dry film 13 is a carboxyl film. The group-containing resin (A) and the crystalline epoxy resin (B1) are contained, and the cover film 14 is a stretched polypropylene film.

According to the 1st aspect, precipitation of the crystalline epoxy resin in the outer surface of a dry film laminated body can be suppressed, and the composition change of a dry film can be suppressed. Thereby, the storage stability of a dry film laminated body can be improved. Moreover, generation | occurrence | production of the powder consisting of the crystalline epoxy resin in the outer surface of a dry film laminated body can also be suppressed by suppressing precipitation of a crystalline epoxy resin. Furthermore, good peelability between the cover film and the dry film can be ensured.

According to the first aspect, thermosetting can be imparted to the dry film.

In the dry film of the second aspect, in the first aspect, the dry compound further comprises an unsaturated compound (C) containing at least one polymerizable ethylenically unsaturated bond in one molecule, and a photopolymerization initiator (D). You may contain.

According to the second aspect, photosensitivity can be imparted to the dry film. Moreover, the outstanding alkali developability can be provided in the non-exposed location of the dry film.

The dry film of the third aspect may further contain a surfactant (E) in the first or second aspect.

According to the third aspect, generation of bubbles and the like when forming the dry film is suppressed, and it becomes easy to form a uniform dry film.

In the dry film of the fourth aspect, in any one of the first to third aspects, the carboxyl group-containing resin (A) may contain a reaction product of a polyol compound and a polyvalent carboxylic acid, The polymerization average molecular weight of the reactant may be in the range of 700 to 40,000, and the acid value of the reactant may be in the range of 50 to 200 mgKOH / g.

According to the fourth aspect, the tackiness of the dry film can be further suppressed, and the insulation reliability and plating resistance of the cured product can be further improved. In addition, the developability of the dry film with an alkaline aqueous solution can be particularly improved.

In any one of the first to fourth aspects, the dry film of the fifth aspect includes an epoxy compound (a1) in which the carboxyl group-containing resin (A) has a bisphenolfluorene skeleton, An intermediate that is a reaction product with a2) and a carboxyl group-containing resin (A1) that is a reaction product of an acid anhydride may be included.

According to the fifth aspect, high heat resistance and plating resistance can be imparted to the cured product of the dry film.

The dry film of the sixth aspect may further contain melamine (F) in any one of the first to fifth aspects.

According to the 6th aspect, favorable adhesiveness can be provided to a dry film, and the adhesiveness between hardened | cured material of a dry film and metals, such as copper, becomes high. For this reason, it is particularly suitable as an insulating material for printed wiring boards. Moreover, the plating property of the cured product of the dry film, that is, the whitening resistance during the electroless nickel / gold plating process is improved.

Claims (6)

1. A base film, a dry film, and a cover film, which are laminated in this order,
   The base film is a polyethylene terephthalate film,
   The dry film contains a carboxyl group-containing resin (A) and a crystalline epoxy resin (B1),
   The cover film is a stretched polypropylene film,
   Dry film laminate.
2. The dry film further comprises an unsaturated compound (C) containing at least one polymerizable ethylenically unsaturated bond in one molecule;
   A photopolymerization initiator (D),
   The dry film laminate according to claim 1.
3. The dry film further contains a surfactant (E).
   The dry film laminated body of Claim 1 or 2.
4. The carboxyl group-containing resin (A) contains a reaction product of a polyol compound and a polyvalent carboxylic acid,
   The reactant has a weight average molecular weight in the range of 700 to 40,000;
   The acid value of the reactant is in the range of 50 to 200 mg KOH / g.
   The dry film laminated body as described in any one of Claims 1 thru | or 3.
5. The carboxyl group-containing resin (A) contains a carboxyl group-containing resin (A1),
   The carboxyl group-containing resin (A1) is a reaction product of an intermediate that is a reaction product of the epoxy compound (a1) and the unsaturated group-containing carboxylic acid (a2), and an acid anhydride,
   The epoxy compound (a1) has a bisphenolfluorene skeleton,
   The bisphenolfluorene skeleton is represented by the following formula (1), in which R ₁ to R ₈ are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen.
   The dry film laminated body as described in any one of Claims 1 thru | or 4.
   

   
6. The dry film further contains melamine (F),
   The dry film laminated body as described in any one of Claims 1 thru | or 5.
   

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