TWI900623B - Photosensitive resin composition - Google Patents

Abstract

The present invention is to provide a photosensitive resin composition having excellent flexibility, which can suppress the formation of concavities caused by aggregates on the surface of the roughened cured product and produce a cured product with high peel strength. The photosensitive resin composition of the present invention comprises: (A) a resin containing ethylenically unsaturated groups and carboxyl groups, (B) an inorganic filler, (C) a photopolymerization initiator, (D) an epoxy resin, and (E) a high molecular weight component. Component (E) has a glass transition temperature of 65°C or lower and a weight-average molecular weight of 1,000 to less than 10,000.

Description

Photosensitive resin composition

The present invention relates to a photosensitive resin composition and further to a photosensitive film, a printed wiring board, and a semiconductor device obtained using the photosensitive resin composition.

Solder resist is applied to printed wiring boards as a permanent protective film to prevent solder from adhering to unwanted areas and to prevent corrosion of the circuit board. Photosensitive resin compositions, such as those described in Patent Document 1, are commonly used as solder resist. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2014-115672

[The problem that the invention aims to solve]

Generally, photosensitive resin compositions are required to have high resolving power during development. Furthermore, with recent attempts to use photosensitive resin compositions as materials for insulating and sealing layers, they are required to have not only high resolving power (developability) but also excellent peel strength from the conductive layer. Furthermore, to enhance the workability of photosensitive films containing photosensitive resin compositions, there is a demand for increased flexibility in photosensitive resin compositions.

The inventors have discovered that when a photosensitive resin composition is photocured, the components of the photosensitive resin composition undergo phase separation, and the resulting phase separation enhances the peeling strength.

However, if the degree of phase separation is excessive, aggregates of specific components will form. When the surface of a cured photosensitive resin composition is roughened, these aggregates fall off, creating depressions on the surface of the roughened cured product. These depressions can easily reduce the surface uniformity and insulation required for solder resist, sealing, or insulating layers. Furthermore, to improve the workability of photosensitive films containing photosensitive resin compositions, there is a demand for increased flexibility in the photosensitive resin composition.

In light of the above-mentioned problems, the present invention aims to provide: a photosensitive resin composition having excellent flexibility, capable of suppressing the formation of pits caused by aggregates on the surface of a roughened cured product and providing a cured product with high peel strength; and a photosensitive film, printed wiring board, and semiconductor device obtained using this photosensitive resin composition. [Means for Solving the Problem]

As a result of intensive research, the inventors discovered that a photosensitive resin composition containing a high molecular weight component having a glass transition temperature of 65°C or lower and a weight-average molecular weight of 1,000 to less than 10,000 is incorporated into a photosensitive resin composition, and further combined with (A) a resin containing ethylenically unsaturated groups and carboxyl groups, (B) an inorganic filler, (C) a photopolymerization initiator, and (D) an epoxy resin. This photosensitive resin composition suppresses the formation of concavities originating from aggregates on the surface of a roughened cured product, resulting in a cured product with high peel strength and excellent flexibility. This led to the completion of the present invention.

That is, the present invention includes the following contents. [1]. A photosensitive resin composition comprising: (A) a resin containing an ethylenically unsaturated group and a carboxyl group, (B) an inorganic filler, (C) a photopolymerization initiator, (D) an epoxy resin, and (E) a high molecular weight component, wherein the glass transition temperature of the component (E) is 65°C or less and the weight average molecular weight is 1000 or more and less than 10000. [2]. A photosensitive resin composition as described in [1], wherein, when the non-volatile components of the photosensitive resin composition are taken as 100% by mass, the content of the component (B) is 50% by mass or more and 85% by mass or less. [3]. The photosensitive resin composition of [1] or [2], wherein the component (E) has one or more groups selected from a carboxyl group, a hydroxyl group, an epoxy group, and a (meth)acryloyl group. [4]. The photosensitive resin composition of any one of [1] to [3], wherein the component (A) has a naphthalene skeleton. [5]. The photosensitive resin composition of any one of [1] to [4], wherein the component (A) is an epoxy (meth)acrylate containing an acid-modified naphthalene skeleton. [6]. The photosensitive resin composition of any one of [1] to [5], wherein the component (D) contains at least one of a biphenyl-type epoxy resin and a glycidylamine-type epoxy resin. [7]. A photosensitive resin composition as described in any one of [1] to [6], wherein the component (B) comprises silicon dioxide. [8]. A photosensitive film comprising the photosensitive resin composition as described in any one of [1] to [7]. [9]. A photosensitive film with a support, comprising a support and a photosensitive resin composition layer disposed on the support, the photosensitive resin composition layer comprising the photosensitive resin composition as described in any one of [1] to [7]. [10]. A printed wiring board comprising an insulating layer formed of a cured product of the photosensitive resin composition as described in any one of [1] to [7]. [11]. A printed wiring board as described in [10], wherein the insulating layer is a solder resist. [12]. A semiconductor device comprising the printed wiring board of [10] or [11]. [Effects of the invention]

The present invention provides a photosensitive resin composition having excellent flexibility, which can suppress the formation of pits caused by aggregates on the surface of a roughened cured product and produce a cured product with high peel strength; and a photosensitive film, a printed wiring board, and a semiconductor device obtained using the photosensitive resin composition.

[Best Mode for Implementing the Invention]

The photosensitive resin composition, photosensitive film, printed wiring board, and semiconductor device of the present invention are described in detail below.

[Photosensitive Resin Composition] The photosensitive resin composition of the present invention comprises: (A) a resin containing ethylenically unsaturated groups and carboxyl groups, (B) an inorganic filler, (C) a photopolymerization initiator, (D) an epoxy resin, and (E) a high molecular weight component. Component (E) has a glass transition temperature of 65°C or lower and a weight-average molecular weight of 1,000 to less than 10,000. This photosensitive resin composition produces a cured product that exhibits excellent flexibility, suppresses the formation of concavities due to aggregates on the surface of the cured product after roughening, and exhibits high peel strength. Furthermore, this photosensitive resin composition generally exhibits excellent developability.

Furthermore, the photosensitive resin composition may contain optional components such as (F) a reactive diluent, (G) a solvent, and (H) other additives as needed. The following describes each component contained in the photosensitive resin composition in detail.

<(A) Resin containing ethylenically unsaturated groups and carboxyl groups> The photosensitive resin composition contains a resin containing ethylenically unsaturated groups and carboxyl groups as component (A). Inclusion of component (A) in the photosensitive resin composition improves resolution.

Ethylenically unsaturated groups have a carbon-carbon double bond, and examples thereof include vinyl, allyl, propargyl, butenyl, ethynyl, phenylethynyl, maleimide, nadicimide, and (meth)acryloyl groups. From the perspective of reactivity in photoradical polymerization, (meth)acryloyl groups are preferred. "(Meth)acryloyl" refers to methacryloyl, acryl, and combinations thereof. Component (A) is capable of photoradical polymerization because it contains ethylenically unsaturated groups. The number of ethylenically unsaturated groups per molecule of component (A) may be one or more. Furthermore, when component (A) contains two or more ethylenically unsaturated groups per molecule, these ethylenically unsaturated groups may be the same or different.

Furthermore, because component (A) contains carboxyl groups, the photosensitive resin composition containing component (A) exhibits solubility in alkaline solutions (e.g., a 1% by mass sodium carbonate aqueous solution, which is an alkaline developer). The number of carboxyl groups per molecule of component (A) may be one or two or more.

Component (A) can be any resin containing ethylenically unsaturated groups and carboxyl groups. Component (A) is preferably at least one of the following: (A-1) a resin containing a naphthalene skeleton, and (A-2) an acid-modified epoxy (meth)acrylate resin.

((A-1) Naphthalene-containing Resin) Because the naphthalene-containing resin (A-1) is a resin in component (A), it contains both ethylenically unsaturated and carboxyl groups. Therefore, component (A-1) is capable of photoradical polymerization, and photosensitive resin compositions containing component (A-1) exhibit solubility in alkaline solutions.

Component (A-1) preferably has multiple ethylenically unsaturated groups per molecule. This improves the mechanical strength and solvent resistance of the cured photosensitive resin composition. Furthermore, component (A-1) preferably has two or fewer ethylenically unsaturated groups per naphthalene backbone. This allows for adjustment of the crosslinking position (crosslinking point), thereby controlling the mechanical strength and solvent resistance of the cured photosensitive resin composition. More preferably, the ethylenically unsaturated group is contained in a substituent on the naphthalene backbone. To incorporate an ethylenically unsaturated group into a substituent on the naphthalene skeleton, a compound in which the H atom of the OH group of naphthol is substituted with an epoxide-containing substituent (e.g., an epoxide or a glycidyl group) is prepared as a first precursor. A compound having an ethylenically unsaturated bond (e.g., an unsaturated carboxylic acid, preferably (meth)acrylic acid) is then added to the first precursor. In this manner, an ethylenically unsaturated group can be introduced into a substituent on the naphthalene skeleton.

Component (A-1) preferably has multiple carboxyl groups per molecule. This improves the solubility of the photosensitive resin composition in alkaline solutions (e.g., alkaline developers). Component (A-1) preferably has two or fewer carboxyl groups per naphthalene skeleton. This allows for controlled solubility. It is further preferred that the carboxyl groups be included in substituents on the naphthalene skeleton. In order to include a carboxyl group in the substituent of the naphthalene skeleton, a compound in which the H atom of the OH group of naphthol is substituted with a substituent containing an epoxide group is prepared as a first precursor. A compound having an ethylenically unsaturated bond (e.g., an unsaturated carboxylic acid, preferably (meth)acrylic acid) is added to the first precursor to obtain a second precursor having a secondary hydroxyl group. A carboxylic anhydride (e.g., tetrahydrophthalic acid) is then added to the second precursor to obtain the second precursor. In this manner, both an ethylenically unsaturated group and a carboxyl group can be introduced into the substituent of the naphthalene skeleton.

Furthermore, component (A-1) is a resin containing a naphthalene skeleton. A resin containing a naphthalene skeleton refers to a compound containing one or more naphthalene skeletons in one molecule. Furthermore, component (A-1) can be dissolved in an alkaline solution (e.g., an alkaline developer) at a dissolution rate within an appropriate range. Furthermore, when a photosensitive resin composition containing component (A-1) is developed with an alkaline developer, the local generation of unexpected over-dissolved portions and unexpected undissolved portions in the photosensitive resin composition can be suppressed. In other words, the BP (break point) can be increased. Therefore, the developability of the photosensitive resin composition can be improved.

Furthermore, when a resin containing a naphthalene skeleton is used as component (A-1), the molecular rigidity is generally increased, thereby suppressing the molecular motion within the photosensitive resin composition. As a result, the glass transition temperature of the cured photosensitive resin composition is increased. Furthermore, due to the action of component (A-1), the resistance to internal stress caused by thermal expansion and contraction is generally improved, thereby enhancing the flexibility of the photosensitive film.

The component (A-1) may contain one naphthalene skeleton in one molecule, or may contain two or more naphthalene skeletons.

The component (A-1) is, for example, a resin containing a structure represented by the following formula (1). The component (A-1) may have a plurality of (e.g., 1 to 10, preferably 1 to 6) structures represented by the following formula (1). When having a plurality of structures represented by the following formula (1), the component (A-1) may contain these plurality of structures represented by the following formula (1) as structural units (repeating units). In addition, in the following formula (1), the bond to which R ¹ is bonded may be bonded to any bondable carbon atom among the carbon atoms possessed by the naphthalene skeleton. Therefore, the bond to which R ¹ is bonded may be bonded to a terminal bond, a carbon atom of the same benzene ring, or a carbon atom of a different benzene ring. The aforementioned terminal bond refers to "bonds to the naphthalene ring other than the bond to ^R1 and the bond to OR'." Specifically, it refers to the bond depicted on the left side of formula (1). For example, the combinations of the positions of the terminal bond in the naphthalene skeleton and the bond to ^R1 can be 1,2, 1,3, 1,4, 1,5, 1,6, 1,7, 1,8, 2,3, 2,6, and 2,7.

In the above formula (1), ^R1 and ^R2 each independently represent an alkylene group which may have a substituent. The number of carbon atoms in ^R1 is generally 1 to 20, preferably 1 to 10, and more preferably 1 to 6. The alkylene group may be a linear or branched chain. Examples of the alkylene group include methylene, ethylene, propylene, and butylene.

Examples of the substituents that R ¹ and R ² may have include, independently, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aralkyl group, a silyl group, an acyl group, an acyloxy group, a carboxyl group, a sulfo group, a cyano group, a nitro group, a hydroxyl group, a hydroxyl group, and a sulfoxy group.

In the above formula (1), X represents an arylene group which may have a substituent. The number of carbon atoms in X is usually 6 to 30, preferably 6 to 20, and more preferably 6 to 10. Examples of the arylene group include phenylene, anthracenyl, phenanthrylene, and biphenylene.

Examples of the substituent that X may have include the same substituents as those that R ¹ and R ² may have.

In the above formula (1), a represents 0 or 1. Here, a is the number of the base X.

In the above formula (1), s represents 0 or 1. Here, s and t represent the number of radicals ^R1 and ^R2 , respectively. Furthermore, in the above formula (1), t represents 0 or 1. However, for s and t, s+t cannot be 0. When a = 1, it is preferred that both s and t are 1. When a = 0, it is preferred that either s or t be 0.

In the above formula (1), OR' represents a substituent on the naphthalene skeleton. In the above formula (1), R' represents an organic group independently including an ethylenically unsaturated group and a carboxyl group.

R' is preferably a group represented by the following formula (2). In the above formula (2), ^R represents a trivalent group, preferably a trivalent alkyl group that may have a substituent (however, a foreign atom may be present between carbon-carbon bonds (CC bonds)). Among them, a trivalent aliphatic alkyl group that may have a substituent is preferred. ^R may be a trivalent residual group containing an epoxide group that may have a substituent. Examples of substituents that ^R may have include the same substituents as those that ^R and ^R may have.

In the above formula (2), ^R4 represents an organic group containing an ethylenically unsaturated group. A preferred example of an organic group containing an ethylenically unsaturated group is a (meth)acryloyloxy group. "(Meth)acryloyloxy" includes acryloxy, methacryloyloxy, and combinations thereof.

In the above formula (2), R ⁵ is an organic group containing a carboxyl group. An example of an organic group containing a carboxyl group is -OCO-R ⁶ -COOH. Here, R ⁶ represents a divalent group. A divalent alkyl group which may have a substituent is preferred as R ^6. The number of carbon atoms in R ⁶ is usually 1 to 30, preferably 1 to 20, and more preferably 1 to 6. Examples of the divalent alkyl group include straight-chain or branched non-cyclic alkylene groups such as methylene, ethylene, propylene, and butylene; saturated or unsaturated divalent alicyclic alkyl groups; and arylene groups such as phenylene and naphthylene. Among them, divalent alicyclic alkyl groups and arylene groups are preferred, and 4-cyclohexenyl and phenylene are particularly preferred. The substituents that ^R6 may have include, for example, the same substituents as those that ^R1 and ^R2 may have. -CO- ^R6 -COOH in -OCO- ^R6 -COOH is generally a residue of a carboxylic anhydride. Examples of carboxylic anhydrides include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride.

In the above formula (1), c is generally an integer of 1 to 6, preferably 1 to 3, and more preferably 1 to 2. Here, c is the number of the base OR'.

- First Example of Component (A-1) (a=1)- A preferred example of component (A-1) is a naphthol aralkyl resin. "Naphthol aralkyl resin" refers to a resin containing a structure obtained by removing the hydrogen atom of the OH group from a naphthol aralkyl group.

Preferred naphthol arane type resins are resins containing a structure in which a=1 in the above formula (1), for example, resins containing a structure represented by the following formula (3).

In the above formula (3), R ¹ , R ² , X, s, t, R' and c are the same as described above. Preferably, both s and t are 1.

Another preferred naphthol aralkyl resin is a resin containing a structure in which c=1, s=1, and t=1 in the above formula (3), for example, a naphthol aralkyl resin containing a divalent group having a structure represented by the following formula (4) or (5).

In the above formula (4) or (5), R ¹ , R ² , X, R', and c are the same as those described above. The naphthol arane type resin represented by the above formula (4) or (5) can be synthesized using the naphthol arane type epoxy resin used in Synthesis Example 1 described later as a raw material. The naphthol arane type epoxy resin can be obtained, for example, as "ESN-475V" (epoxy equivalent 325 g/eq.) manufactured by Nippon Steel & Sumitomo Chemicals Co., Ltd.

-Second example of component (A-1) (a=0) - Among the components (A-1), a preferred example other than the naphthol arane type resin (a=0) is a resin containing a structure in which c=2, s=1, and t=0 in the above formula (1), for example, a resin containing a naphthalene skeleton and a divalent group having a structure represented by the following formula (6). In the above formula (6), R ¹ , R 1 , and R ' are the same as those described above. The resin containing a naphthalene skeleton represented by the above formula (6) can be synthesized using 1,1'-bis(2,7-diglycidyloxynaphthyl)methane as a raw material. Such a naphthalene skeleton-containing epoxy resin can be obtained, for example, as "EXA-4700" manufactured by Dainippon Ink & Chemicals.

The weight average molecular weight of component (A-1) is preferably 500 or greater, more preferably 1000 or greater, even more preferably 1500 or greater, and even more preferably 2000 or greater from the perspective of film-forming properties. The upper limit is preferably 10,000 or less, even more preferably 8,000 or less, and even more preferably 7,500 or less from the perspective of developing properties. The weight average molecular weight is the polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

-Method for Producing Component (A-1)- Component (A-1) is not particularly limited to the examples above, as long as it is a compound containing a resin containing a naphthalene skeleton, an ethylenically unsaturated group, and a carboxyl group. One embodiment thereof includes an epoxy ester resin containing an acid-modified unsaturated naphthalene skeleton, obtained by reacting an unsaturated carboxylic acid with a naphthalene-type epoxy compound (epoxy compound containing a naphthalene skeleton), followed by a reaction with a carboxylic anhydride. The method for producing an epoxy ester resin containing an acid-modified unsaturated naphthalene skeleton will now be described. First, an unsaturated carboxylic acid is reacted with an epoxy compound containing a naphthalene skeleton to obtain an epoxy ester resin containing an unsaturated naphthalene skeleton. Next, the carboxylic anhydride is reacted with the epoxy ester resin containing an unsaturated naphthalene skeleton. In this way, an epoxy ester resin containing an acid-modified unsaturated naphthalene skeleton can be obtained.

As the naphthalene skeleton-containing epoxy compound, any compound having one or more epoxy groups in the molecule can be used. Examples include naphthalene-type epoxy resins having a naphthalene skeleton in the molecule, such as monohydroxynaphthalene-type epoxy resins, dihydroxynaphthalene-type epoxy resins, polyhydroxybinaphthyl-type epoxy resins, naphthalene-type epoxy resins obtained by the condensation reaction of polyhydroxynaphthalene and aldehydes, and binaphthol-type epoxy resins. Any of these may be used alone or in combination of two or more.

Examples of monohydroxynaphthalene epoxy resins include 1-glycidyloxynaphthalene and 2-glycidyloxynaphthalene. Examples of dihydroxynaphthalene epoxy resins include 1,3-diglycidyloxynaphthalene, 1,4-diglycidyloxynaphthalene, 1,5-diglycidyloxynaphthalene, 1,6-diglycidyloxynaphthalene, 2,3-diglycidyloxynaphthalene, 2,6-diglycidyloxynaphthalene, and 2,7-diglycidyloxynaphthalene.

Examples of the polyhydroxybinaphthyl epoxy resin include 1,1'-bis-(2-glycidyloxy)naphthyl, 1-(2,7-diglycidyloxy)-1'-(2'-glycidyloxy)binaphthyl, and 1,1'-bis-(2,7-diglycidyloxy)naphthyl.

Examples of naphthalene-type epoxy resins obtained by the condensation reaction of polyhydroxynaphthalene and aldehydes include 1,1'-bis(2,7-diglycidyloxynaphthyl)methane, 1-(2,7-diglycidyloxynaphthyl)-1'-(2'-glycidyloxynaphthyl)methane, and 1,1'-bis(2-glycidyloxynaphthyl)methane.

Among these, polyhydroxybinaphthyl epoxy resins having two or more naphthalene skeletons in one molecule and naphthalene epoxy resins obtained by the condensation reaction of polyhydroxynaphthalene with aldehydes are preferred. In particular, 1,1'-bis(2,7-diglycidyloxynaphthyl)methane, 1-(2,7-diglycidyloxynaphthyl)-1'-(2'-glycidyloxynaphthyl)methane, 1-(2,7-diglycidyloxy)-1'-(2'-glycidyloxy)binaphthyl, and 1,1'-bis-(2,7-diglycidyloxy)naphthyl, each having three or more epoxy groups in one molecule, are preferred because they have excellent heat resistance in addition to their high mean linear thermal expansion coefficient.

Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, cinnamic acid, and crotonic acid. These can be used alone or in combination of two or more. Of these, acrylic acid and methacrylic acid are preferred from the perspective of enhancing the photocurability of the photosensitive resin composition. Furthermore, in this specification, the naphthalene-type epoxy ester resin, which is the reaction product of the above-mentioned naphthalene-type epoxy compound and (meth)acrylic acid, is sometimes described as "naphthalene-type epoxy (meth)acrylate." Here, the epoxy group of the naphthalene-type epoxy compound is generally substantially eliminated by the reaction with (meth)acrylic acid. "(Meth)acrylate" includes methacrylate, acrylate, and combinations thereof. Acrylic acid and methacrylic acid are sometimes collectively referred to as "(meth)acrylic acid."

Examples of carboxylic anhydrides include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride. Any one of these can be used alone, or two or more can be used in combination. Among these, succinic anhydride and tetrahydrophthalic anhydride are preferred because they improve the developability and insulation reliability of the cured product.

When obtaining an epoxy ester resin containing an acid-modified unsaturated naphthalene skeleton, an unsaturated carboxylic acid is reacted with an epoxy compound containing a naphthalene skeleton in the presence of a catalyst to obtain an epoxy ester resin containing an unsaturated naphthalene skeleton. The epoxy ester resin containing an unsaturated naphthalene skeleton can then be reacted with a carboxylic anhydride.

The amount of the catalyst used in this case is preferably 2% by mass or less, more preferably in the range of 0.0005% by mass to 1% by mass, and even more preferably in the range of 0.001% by mass to 0.5% by mass, relative to the total mass of the unsaturated carboxylic acid, the epoxide compound containing a naphthalene skeleton, and the carboxylic anhydride. As the catalyst, for example, N-methylphenoxyethanol, pyridine, 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), 1,5-diazabicyclo[4.3.0]nonene-5 (DBN), 1,4-diazabicyclo[2.2.2]octane (DABCO), tri-n-butylamine or dimethylbenzylamine, butylamine, octylamine, monoethanolamine, diethanolamine, triethanolamine, imidazole, 1-methylimidazole, 2,4-dimethylimidazole, 1,4-diethylimidazole, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(N-phenyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, Representative relative anions include various amine compounds such as trimethylphosphine, tributylphosphine, and triphenylphosphine; and phosphonium salts such as tetramethylphosphonium salt, tetraethylphosphonium salt, tetrapropylphosphonium salt, tetrabutylphosphonium salt, trimethyl(2-hydroxypropyl)phosphonium salt, triphenylphosphonium salt, and benzylphosphonium salt. Examples include phosphonium salts with chlorides, bromides, carboxylates, and hydroxides; trimethylsiliconium salts, benzyltetramethylenesilicon salts, phenylbenzylmethylsiliconium salts, and phenyldimethylsiliconium salts; and representative counter anions include carboxylates and hydroxides; and acidic compounds such as phosphoric acid, p-toluenesulfonic acid, and sulfuric acid. The reaction can be carried out at a temperature between 50°C and 150°C, preferably between 80°C and 120°C.

When obtaining an epoxy ester resin containing an acid-modified unsaturated naphthalene skeleton, an organic solvent may be used. As the organic solvent, the same solvent as the solvent (G) described below can be used.

When obtaining an epoxy ester resin containing an acid-modified unsaturated naphthalene skeleton, a polymerization inhibitor such as hydroquinone may be used. The amount of the polymerization inhibitor used is preferably 2% by mass or less, more preferably in the range of 0.0005% by mass to 1% by mass, and even more preferably in the range of 0.001% by mass to 0.5% by mass, relative to the combined mass of the unsaturated carboxylic acid, the naphthalene skeleton-containing epoxy compound, and the carboxylic anhydride.

Epoxy (meth)acrylates containing an acid-modified unsaturated naphthalene skeleton are preferred as epoxy ester resins containing an acid-modified unsaturated naphthalene skeleton. Epoxy (meth)acrylates containing an acid-modified naphthalene skeleton are epoxy ester resins containing an acid-modified unsaturated naphthalene skeleton obtained by using an epoxy compound containing a naphthalene skeleton and (meth)acrylic acid as the unsaturated carboxylic acid.

Another embodiment of component (A-1) includes reacting an ethylenically unsaturated group and an epoxy compound containing a naphthalene skeleton with a (meth)acrylic resin contained in a structural unit obtained by polymerizing (meth)acrylic acid to produce a (meth)acrylic resin containing an unsaturated modified naphthalene skeleton into which an ethylenically unsaturated group has been introduced. Furthermore, a carboxylic anhydride can be reacted with the hydroxyl group generated during the introduction of the unsaturated group. The carboxylic anhydride can be the same as the acid anhydride described above, and the preferred range is the same.

((A-2) Acid-modified epoxy (meth)acrylate resin) The acid-modified epoxy (meth)acrylate resin as component (A-2) is a compound having a structure in which a carboxyl group has been introduced into the (meth)acrylate ester of an epoxy compound. However, component (A-2) does not contain component (A-1).

One embodiment of component (A-2) includes acid-modified cresol novolac-type epoxy (meth)acrylates obtained by reacting (meth)acrylic acid with a cresol novolac-type epoxy compound such as cresol novolac-type epoxy compound A or cresol novolac-type epoxy compound, followed by a reaction with a carboxylic anhydride. Specifically, the acid-modified cresol novolac-type epoxy (meth)acrylate can be obtained by reacting (meth)acrylic acid with a cresol novolac-type epoxy compound to obtain a cresol novolac-type epoxy (meth)acrylate, and then reacting the cresol novolac-type epoxy (meth)acrylate with a carboxylic anhydride.

Another embodiment of the component (A-2) includes acid-modified epoxy (meth)acrylates obtained by reacting (meth)acrylic acid with an epoxy compound other than the above-mentioned cresol novolac-type epoxy compound, and then reacting the resulting mixture with a carboxylic anhydride. Examples of such epoxy compounds include biphenyl epoxy compounds; bisphenol-type epoxy compounds such as bisphenol A epoxy compounds and bisphenol F epoxy compounds; phenol novolac epoxy resins; novolac epoxy resins such as bisphenol A novolac epoxy resins and alkylphenol novolac epoxy resins; fluorine-containing epoxy resins such as perfluoroalkyl epoxy resins; dimethylphenol epoxy resins; dicyclopentadiene epoxy resins; trisphenol epoxy resins, tert-butyl-catechol epoxy resins, anthracene epoxy resins, and the like. Epoxy resins with condensed cyclic skeletons; glycidylamine-type epoxy resins; glycidyl ester-type epoxy resins; linear aliphatic epoxy resins; epoxy resins with a butadiene structure; alicyclic epoxy resins; heterocyclic epoxy resins; epoxy resins containing spiro rings; cyclohexanedimethanol-type epoxy resins; trihydroxymethylpropane-type epoxy resins; tetraphenylethane-type epoxy resins; acrylic resins containing glycidyl groups such as polyglycidyl (meth)acrylate and copolymers of glycidyl methacrylate and acrylate; fluorene-type epoxy resins; halogenated epoxy resins, etc.

As such acid-modified epoxy (meth)acrylates, commercially available products can be used. Specific examples include "CCR-1179" (cresol novolac F type epoxy acrylate), "ZAR-2000" (acid-modified bisphenol type epoxy acrylate: a reaction product of bisphenol A type epoxy resin, acrylic acid, and succinic anhydride), and "ZFR-1491H" (acid-modified bisphenol type epoxy acrylate: a reaction product of bisphenol F type epoxy resin, Examples include "ZFR-1533H" (acid-modified bisphenol-type epoxy acrylate: a reaction product of bisphenol F-type epoxy resin, acrylic acid, and tetrahydrophthalic anhydride), "ZCR-1569H" (acid-modified biphenyl-type epoxy acrylate: a reaction product of biphenyl-type epoxy resin, acrylic acid, and acid anhydride), and "PR-300CP" manufactured by Showa Denko K.K. (a reaction product of cresol novolac-type epoxy resin, acrylic acid, and acid anhydride). These can be used alone or in combination.

Another embodiment of component (A-2) includes an unsaturated modified (meth)acrylate resin having an ethylenically unsaturated group introduced therein, obtained by reacting an epoxy compound (meth)acrylate with a (meth)acrylate resin contained in a structural unit obtained by polymerizing (meth)acrylic acid. Examples of epoxy compound (meth)acrylates include glycidyl methacrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth)acrylate. Furthermore, a carboxylic anhydride can be reacted with the hydroxyl group generated during the introduction of the unsaturated group. The carboxylic anhydride used can be the same as those described above, and the preferred range is the same.

Commercially available unsaturated modified (meth)acrylate resins of this type can be used. Specific examples include "SPC-1000" and "SPC-3000" manufactured by Showa Denko K.K., and "Cyclomer P(ACA)Z-250," "Cyclomer P(ACA)Z-251," "Cyclomer P(ACA)Z-254," "Cyclomer P(ACA)Z-300," and "Cyclomer P(ACA)Z-320" manufactured by Daicel-Allnex.

The weight average molecular weight of component (A-2) is preferably 1000 or greater, more preferably 1500 or greater, and even more preferably 2000 or greater from the perspective of film-forming properties. The upper limit is preferably 20,000 or less, more preferably 15,000 or less, and even more preferably 14,000 or less from the perspective of developability. The weight average molecular weight is the polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

The component (A) may be a component (A-3) other than the above-mentioned components (A-1) and (A-2). This component does not include the components (A-1) and (A-2).

The weight average molecular weight and acid value of component (A-3) are optional, but are preferably within the same range as those of component (A-2) described above. This provides the same advantages as those described for component (A-2).

From the perspective of improving the solubility of the photosensitive resin composition in alkaline solutions, the acid value of component (A) is 0.1 mgKOH/g or higher, preferably 0.5 mgKOH/g or higher or 1 mgKOH/g or higher. On the other hand, from the perspective of suppressing the dissolution of fine patterns of the cured product in alkaline solutions, an acid value of 150 mgKOH/g or lower is preferred, 120 mgKOH/g or lower is even more preferred, and 100 mgKOH/g or lower is even more preferred. Here, the acid value refers to the residual acid value of the carboxyl groups present in component (A), and the acid value can be measured by the following method. First, accurately weigh approximately 1 g of the resin solution, then add 30 g of acetone to the resin solution and evenly dissolve the resin solution. Next, an appropriate amount of phenolphthalein as an indicator is added to the solution and titrated using a 0.1N ethanolic KOH solution. Furthermore, the acid value is calculated according to the following formula (1). Formula: A=Vf×5.611/(Wp×I)      ・・・(1)

In the above formula (1), A represents the acid value [mgKOH/g], Vf represents the titration amount of the KOH solution [mL], Wp represents the mass of the measured resin solution [g], and I represents the ratio of the non-volatile component in the measured resin solution [mass %].

From the perspective of adjusting the solubility of the photosensitive resin composition in alkaline solutions, the content of component (A) is preferably 5% by mass or greater, more preferably 10% by mass or greater, and even more preferably 15% by mass or greater, based on 100% by mass of the nonvolatile components in the photosensitive resin composition. It is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less. In the present invention, unless otherwise specified, the content of each component in the photosensitive resin composition is based on 100% by mass of the nonvolatile components in the photosensitive resin composition.

<(B) Inorganic Filler> The photosensitive resin composition contains (B) an inorganic filler as component (B). By including component (B), a photosensitive resin composition can be provided that can produce a cured product with excellent insulating properties.

(B) The material of the inorganic filler is not particularly limited. Examples thereof include silicon dioxide, aluminum dioxide, glass, cordierite, silica, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, hydroaluminite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanium oxide, calcium titanium oxide, magnesium titanium oxide, bismuth titanium oxide, titanium oxide, zirconium oxide, barium titanium oxide, barium zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silicon dioxide is particularly suitable. Spherical silicon dioxide is particularly preferred. (B) The inorganic filler may be used alone or in combination of two or more.

From the perspective of obtaining a cured product with low dielectric constant and dielectric tangent, the average particle size of the inorganic filler (B) is preferably 10 μm or less, more preferably 5 μm or less, more preferably 3 μm or less, 2 μm or less, 1 μm or less, or 0.7 μm or less. The lower limit of the average particle size is not particularly limited, but is preferably 0.01 μm or greater, more preferably 0.05 μm or greater, more preferably 0.07 μm or greater, 0.1 μm or greater, or 0.2 μm or greater.

The average particle size of inorganic fillers can be measured using the Mie scattering theory using laser diffraction/scattering. Specifically, a volume-based particle size distribution of the inorganic filler can be generated using a laser diffraction/scattering particle size distribution analyzer, and the median particle size is used as the average particle size for measurement. The measurement sample is preferably one in which the inorganic filler is ultrasonically dispersed in water. Examples of laser diffraction/scattering particle size distribution analyzers include the LA-500 manufactured by Horiba, Ltd. and the SALD-2200 manufactured by Shimadzu Corporation.

From the perspective of obtaining a cured product with low dielectric constant and dielectric tangent, the specific surface area of the inorganic filler (B) is preferably 1 ^m² /g or greater, more preferably 3 ^m² /g or greater, and particularly preferably 5 ^m² /g or greater. While there is no particular upper limit, it is preferably 60 ^m² /g or less, 50 ^m² /g or less, or 40 ^m² /g or less. The specific surface area is obtained by adsorbing nitrogen onto the sample surface using a specific surface area measurement device (Macsorb HM-1210, manufactured by Mountech) using the BET method and calculating the specific surface area using the BET multipoint method.

From the perspective of improving moisture resistance and dispersibility, the inorganic filler (B) is preferably treated with one or more surface treatment agents selected from the group consisting of aminosilane-based coupling agents, epoxysilane-based coupling agents, phenylsilane-based coupling agents, silane-based coupling agents, alkoxysilane compounds, organosilazane compounds, and titanium ester-based coupling agents. Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical, "KBM803" (3-hydroxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical, "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical, "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical, "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical, "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical, and "KBM-4803" (long-chain epoxy-type silane coupling agent) manufactured by Shin-Etsu Chemical.

(B) Inorganic fillers may be commercially available products. Examples of commercially available products include "SC2050," "SC4050," and "ADMAFINE" manufactured by Admatechs, "SFP series" manufactured by Denki Kagaku Kogyo Co., Ltd., "SP(H) series" manufactured by Nippon Steel & Sumikin Materials, "Sciqas series" manufactured by Sakai Chemical Industry Co., Ltd., "SEAHOSTAR series" manufactured by Nippon Catalyst Co., Ltd., "AZ series" and "AX series" manufactured by Nippon Steel & Sumikin Materials, and "B series" and "BF series" manufactured by Sakai Chemical Industry Co., Ltd.

From the perspective of obtaining a cured product with low dielectric constant and dielectric tangent, the content of the inorganic filler (B) is preferably 50% by mass or greater, more preferably 55% by mass or greater, and even more preferably 60% by mass or greater, based on 100% by mass of the non-volatile components in the photosensitive resin composition. From the perspective of suppressing light reflection during exposure and achieving excellent developability, the upper limit is, for example, 85% by mass or less, 70% by mass or less, or 65% by mass or less.

<(C) Photopolymerization Initiator> The photosensitive resin composition contains a photopolymerization initiator as component (C). By including the photopolymerization initiator (C) in the photosensitive resin composition, the photosensitive resin composition can be efficiently photocured.

(C) The photopolymerization initiator may be any compound, for example, acylphosphine oxide-based photopolymerization initiators such as bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide and 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide; 1,2-octanedione, 1-4-(phenylthio)-2-(O-benzoyl oxime), acetone, 1-[9-ethyl- Oxime ester photopolymerization initiators such as 6-(2-methylbenzyl)-9H-carbazol-3-yl]-, 1-(O-acetyl oxime); 2-benzyl-2-dimethylamino-1-(4-oxolinylphenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-[4-(4-oxolinyl)phenyl]-1-butanone, 2-methyl -1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one and other α-alkyl phenone-based photopolymerization initiators; benzophenone, methyl benzophenone, o-benzoylbenzoic acid, benzoylethyl ether, 2,2-diethoxyacetophenone, 2,4-diethylthioxanthone, diphenyl-(2,4,6-trimethylbenzyl)phosphine oxide, ethyl-(2, Copper salt-based photopolymerization initiators such as 4,6-trimethylbenzyl)phenylphosphinic acid, 4,4'-bis(diethylamino)benzophenone, 1-hydroxycyclohexyl-phenyl ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, and 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one can also be used. These can be used alone or in combination of two or more. Of these, acylphosphine oxide-based photopolymerization initiators and oxime ester-based photopolymerization initiators are preferred for more efficient photocuring of the photosensitive resin composition, with acylphosphine oxide-based photopolymerization initiators being particularly preferred. These may be used alone or in combination of two or more.

Specific examples of the (C) photopolymerization initiator include "Omnirad 907", "Omnirad 369", "Omnirad 379", "Omnirad 819", and "Omnirad TPO" manufactured by IGM Resins, "Irgacure OXE-01", "Irgacure OXE-02", "Irgacure TPO", and "Irgacure 819" manufactured by BASF, and "N-1919" manufactured by ADEKA.

The content of the photopolymerization initiator (C) is preferably 1% by mass or greater, more preferably 1.5% by mass or greater, and even more preferably 2% by mass or greater, based on 100% by mass of the non-volatile components of the photosensitive resin composition, from the perspective of sufficient photocuring of the photosensitive resin composition and improved insulation reliability. On the other hand, from the perspective of suppressing a decrease in developability due to excessive sensitivity, the upper limit is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less.

Furthermore, the photosensitive resin composition may include tertiary amines such as ethyl N,N-dimethylaminobenzoate, isoamyl N,N-dimethylaminobenzoate, amyl-4-dimethylaminobenzoate, triethylamine, and triethanolamine as photopolymerization initiators in combination with component (C). The photosensitive resin composition may also include photosensitizers such as pyrazolines, anthracenes, coumarins, xanthones, and thioxanthones in combination with component (C). Any of these may be used alone or in combination of two or more.

<(D) Epoxy Resin> The photosensitive resin composition contains an epoxy resin as component (D). Inclusion of component (D) improves insulation reliability. However, component (D) herein does not include epoxy resins containing ethylenically unsaturated groups or carboxyl groups. Furthermore, component (D) does not include any component equivalent to component (E).

Examples of the component (D) include bixylene type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, glycidylamine type epoxy resins, Glycidyl ester epoxy resins, cresol novolac epoxy resins, biphenyl epoxy resins, linear aliphatic epoxy resins, epoxy resins with a butadiene structure, aliphatic epoxy resins, heterocyclic epoxy resins, epoxy resins containing spiro rings, oxalic acid ester epoxy resins, oxalic acid dimethanol epoxy resins, naphthyl ether epoxy resins, trihydroxymethylpropane epoxy resins, tetraphenylethane epoxy resins, tetraglycidyl diaminodiphenylmethane epoxy resins, etc. Among them, as component (D), either a biphenyl-type epoxy resin or a glycidylamine-type epoxy resin is preferred. The epoxy resin may be used alone or in combination of two or more.

The resin composition preferably includes an epoxy resin having two or more epoxy groups per molecule as component (D). From the perspective of significantly achieving the desired effects of the present invention, the proportion of the epoxy resin having two or more epoxy groups per molecule relative to 100% by mass of the non-volatile component in component (D) is preferably 50% by mass or greater, more preferably 60% by mass or greater, and particularly preferably 70% by mass or greater.

Epoxy resins include epoxy resins that are liquid at 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at 20°C (hereinafter sometimes referred to as "solid epoxy resins"). The resin composition may contain only the liquid epoxy resin or only the solid epoxy resin as component (D). However, from the perspective of significantly achieving the desired effects of the present invention, a combination of the liquid epoxy resin and the solid epoxy resin is preferred.

The solid epoxy resin is preferably a solid epoxy resin having three or more epoxy groups in one molecule, and is more preferably an aromatic solid epoxy resin having three or more epoxy groups in one molecule.

Preferred solid epoxy resins include biphenylol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthyl ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, and tetraphenylethane-type epoxy resins, with biphenyl-type epoxy resins being particularly preferred.

Specific examples of solid epoxy resins include "HP4032H" (naphthalene-based epoxy resin) manufactured by DIC Corporation; "HP-4700" and "HP-4710" (naphthalene-based tetrafunctional epoxy resins) manufactured by DIC Corporation; "N-690" (cresol novolac-based epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolac-based epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH" and "HP-7200H" (dicyclopentadiene-based epoxy resin) manufactured by DIC Corporation; EXA-7311, EXA-7311-G3, EXA-7311-G4, EXA-7311-G4S, and HP6000 (naphthyl ether epoxy resins); EPPN-502H (trisphenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; NC7000L (naphthol novolac epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; NC3000H, NC3000, NC3000L, and NC3100 (biphenyl epoxy resins) manufactured by Nippon Kayaku Co., Ltd.; "ESN475V" (naphthol-type epoxy resin) manufactured by STEEL Chemical & Material Co., Ltd.; "ESN485" (naphthol-phenol novolac-type epoxy resin) manufactured by NIPPON STEEL Chemical & Material Co., Ltd.; "YX4000H", "YX4000", and "YL6121" (biphenyl-type epoxy resins) manufactured by Mitsubishi Chemical Co., Ltd.; "YX4000HK" (dimethylol-type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; Mitsubishi Examples include "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "jER1010" (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; and "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd. These can be used alone or in combination.

The liquid epoxy resin is preferably one having two or more epoxy groups in one molecule.

Preferred liquid epoxy resins include bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol AF-type epoxy resins, naphthalene-type epoxy resins, glycidyl ester-type epoxy resins, glycidylamine-type epoxy resins, phenol novolac-type epoxy resins, aliphatic epoxy resins having an ester skeleton, oxalic acid-type epoxy resins, oxalic acid-dimethanol-type epoxy resins, glycidylamine-type epoxy resins, and epoxy resins having a butadiene structure, with glycidylamine-type epoxy resins being particularly preferred. As the glycidylamine type epoxy resin, tetraglycidyl diamino diphenylmethane type epoxy resin is preferred.

Specific examples of liquid epoxy resins include "HP4032", "HP4032D", and "HP4032SS" (naphthalene-type epoxy resins) manufactured by DIC Corporation; "828US", "jER828EL", "825", and "Epikote 828EL" (bisphenol A-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER807" and "1750" (bisphenol F-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630" and "630LSD" (glycidylamine-type epoxy resins) manufactured by Mitsubishi Chemical Corporation; and NIPPON STEEL Chemical. & Material Co., Ltd.'s "ZX1059" (a mixture of bisphenol A and bisphenol F epoxy resins); Nagasechemtex Co., Ltd.'s "EX-721" (a glycidyl ester epoxy resin); Daicel Co., Ltd.'s "Celloxide 2021P" (a lipid-based epoxy resin with an ester backbone); Daicel Co., Ltd.'s "PB-3600" (an epoxy resin with a butadiene structure); NIPPON STEEL Chemical Co., Ltd. "ZX1658" and "ZX1658GS" (liquid 1,4-glyceryl cyclohexane type epoxy resin) manufactured by Material Co., Ltd.; "ELM-434L" (glyceryl amine type epoxy resin) manufactured by Sumitomo Chemical Co., Ltd.; "ELM-434VL" (tetraglyceryl diaminodiphenylmethane type epoxy resin) manufactured by Sumitomo Chemical Co., Ltd.; "EP-39 Examples include "EP-80S" (a bifunctional glycidylamine-type epoxy resin); ADEKA's "EP-3950L" (a trifunctional glycidylamine-type epoxy resin); Nissan Chemical's "TEPIC-VL" (an isocyanuric acid epoxy resin); and Sumitomo Chemical's "ELM-100H" (N-[2-methyl-4-(oxiranylmethoxy)phenyl]-N-(oxiranylmethyl)oxiranemethylamine). These can be used alone or in combination.

When a liquid epoxy resin and a solid epoxy resin are used in combination as component (D), the mass ratio (liquid epoxy resin:solid epoxy resin) is preferably 1:0.01 to 1:20, more preferably 1:0.1 to 1:10, and particularly preferably 1:0.5 to 1:5. By maintaining the mass ratio of the liquid epoxy resin to the solid epoxy resin within the above range, the desired effects of the present invention are significantly achieved. Furthermore, when typically used in the form of a resin sheet, moderate adhesion is achieved. Furthermore, when typically used in the form of a resin sheet, sufficient flexibility is achieved, resulting in improved handling. Furthermore, a cured product having sufficient breaking strength can usually be obtained.

The epoxy equivalent weight of component (D) is preferably 50 g/eq. to 5000 g/eq., more preferably 50 g/eq. to 3000 g/eq., more preferably 80 g/eq. to 2000 g/eq., and even more preferably 110 g/eq. to 1000 g/eq. Within this range, the cured resin composition layer has a sufficient crosslinking density, resulting in an insulating layer with minimal surface roughness. The epoxy equivalent weight refers to the mass of the epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent weight can be measured in accordance with JIS K7236.

To significantly achieve the desired effects of the present invention, the weight average molecular weight (Mw) of component (D) is preferably 100-5000, more preferably 200-3000, and even more preferably 250-1500. The weight average molecular weight of the resin can be measured using gel permeation chromatography (GPC) as a polystyrene-equivalent value.

From the perspective of obtaining an insulating layer exhibiting excellent mechanical strength and insulation reliability, the content of component (D) is preferably 1% by mass or greater, more preferably 3% by mass or greater, and even more preferably 5% by mass or greater, based on 100% by mass of the non-volatile components in the resin composition. From the perspective of significantly achieving the desired effects of the present invention, the upper limit of the epoxy resin content is preferably 25% by mass or less, more preferably 20% by mass or less, and particularly preferably 15% by mass or less.

<(E) High Molecular Weight Component> The photosensitive resin composition contains a high molecular weight component (E) as component (E). Component (E) has a glass transition temperature of 65°C or lower and a weight-average molecular weight of 1,000 to less than 10,000. However, component (E) does not include a component equivalent to component (A). The inclusion of component (E) in the photosensitive resin composition enables high peel strength when a conductive layer is formed by coating on a roughened surface of a cured product. Furthermore, component (E) suppresses the formation of concavities caused by aggregates on the surface of the roughened cured product, enabling the formation of fine wiring on the cured surface. Furthermore, component (E) generally enhances flexibility and resolution. Component (E) may be used alone or in combination of two or more.

From the perspective of suppressing the formation of pits originating from aggregates on the surface of the cured product after roughening treatment, the weight-average molecular weight of the high-molecular-weight component (E) is 1000 or greater, preferably 1500 or greater, and more preferably 2000 or greater, or 3000 or greater. The upper limit is less than 10,000, preferably 8000 or less, and more preferably 5000 or less. The weight-average molecular weight of the component (E) is the polystyrene-equivalent weight-average molecular weight measured by gel permeation chromatography (GPC).

From the perspective of developing a sea-island structure after roughening treatment and achieving high peel strength during conductive layer formation, the glass transition temperature (Tg) of component (E) is 65°C or lower, preferably 60°C or lower, and more preferably 50°C or lower, 40°C or lower, 30°C or lower, 20°C or lower, 10°C or lower, 0°C or lower, -10°C or lower, -20°C or lower, -30°C or lower, -35°C or lower, or -40°C or lower. The lower limit is preferably -100°C or higher, more preferably -80°C or higher, and even more preferably -75°C or higher.

The glass transition temperature (Tg) can be measured using differential scanning calorimetry at a heating rate of 5°C/min based on JIS K 7121.

The inventors speculate that the mechanism by which the aforementioned superior effects are achieved by using component (E) having the aforementioned combination of weight-average molecular weight and glass transition temperature is as follows. However, the technical scope of the present invention is not limited to the following mechanism. The resin components contained in the photosensitive resin composition generally form a sea-island structure with component (E) serving as islands and resin components other than component (E) serving as seas. Here, "resin components" refer to the non-volatile components contained in the photosensitive resin composition, excluding inorganic fillers. Furthermore, when the cured photosensitive resin composition is subjected to a roughening treatment, the treatment solution easily penetrates the interface between the sea and the islands, resulting in depressions of a size related to the size of the sea after the roughening treatment. Here, component (E), which has the aforementioned combination of weight-average molecular weight and glass transition temperature, is well dispersed in the photosensitive resin composition due to its small molecular size and high molecular flexibility. Consequently, the islands of component (E) contained in the sea-island structure can be very small. Consequently, the surface of the roughened cured product can have numerous small depressions, significantly increasing its surface area and achieving a high anchoring effect. Furthermore, the high flexibility of component (E) enhances the toughness of the cured product of the photosensitive resin composition and provides high mechanical strength, thereby suppressing peeling associated with the destruction of the cured product. Consequently, enhanced peeling strength can be achieved. Furthermore, because component (E) is well dispersed in the photosensitive resin composition, agglomerates of component (E) are less likely to form in the cured product. This prevents the formation of large depressions caused by the shedding of aggregates, thereby suppressing the formation of depressions on the surface of the cured product. Furthermore, since component (E) generally has excellent flexibility, the cured product can achieve high flexibility.

Component (E) may have a glass transition temperature and weight-average molecular weight within the above-mentioned ranges. Examples of such components include (meth)acrylic resins, polyester resins, polyurethane resins, polyether resins, and polyolefin resins. "(Meth)acrylic resins" include acrylic acid, methacrylic acid, and combinations thereof.

Furthermore, from the perspective of achieving a more pronounced effect of the present invention by allowing component (E) to be well dispersed in the resin composition and exhibiting a denser sea-island structure, component (E) preferably has a functional group that reacts with component (D). Examples of such functional groups include carboxyl, hydroxyl, epoxy, and (meth)acryloyl groups. Among these, the functional groups preferably have one or more functional groups selected from carboxyl, hydroxyl, epoxy, and (meth)acryloyl groups, more preferably either carboxyl or hydroxyl groups, and even more preferably hydroxyl groups.

The functional group may be present at the terminal end of component (E) or within the repeating unit. It is preferred that the functional group be present within the repeating unit. The number of functional groups per molecule of component (E) may be one or two or more. Furthermore, when component (E) contains two or more functional groups per molecule, these functional groups may be the same or different.

A suitable embodiment of the component (E) is a (meth)acrylic resin. Examples of the (meth)acrylic resin include carboxyl-containing (meth)acrylic resins, hydroxyl-containing (meth)acrylic resins, epoxy-containing (meth)acrylic resins, and (meth)acryloyl-containing (meth)acrylic resins. Among them, carboxyl-containing (meth)acrylic resins and hydroxyl-containing (meth)acrylic resins are preferred.

Examples of the main skeleton (repeating units) of the (meth)acrylic resin include structural units derived from methacrylate (MA), structural units derived from ethyl acrylate (EA), structural units derived from butyl acrylate (BA), structural units derived from 2-ethylhexyl acrylate (2EHA), and structural units derived from methyl methacrylate (MMA). Among them, the main skeleton of the (meth)acrylic resin is preferably composed of structural units derived from butyl (meth)acrylate or structural units derived from 2-ethylhexyl (meth)acrylate, and more preferably structural units derived from 2-ethylhexyl (meth)acrylate.

Commercially available (meth)acrylate resins can be used. Examples of commercially available (meth)acrylate resins include "CB-3060," "CB-3098," "CBB-3098," and "UT-1001" manufactured by Soken Chemical Co., Ltd., and "BPX-003" manufactured by Negami Industries, Ltd.

Another suitable embodiment of component (E) is a polyester resin. Examples of the polyester resin include carboxyl-containing polyester resins, hydroxyl-containing polyester resins, epoxy-containing polyester resins, and (meth)acryl-containing polyester resins.

Examples of polyester resins include fatty acid autocondensates and fatty acid esters, which are polycondensates of alcohols such as polyglycerol and fatty acids. Of these, fatty acid autocondensates are preferred as polyester resins. These can be synthesized by heating fatty acids.

The fatty acid may have a substituent such as a hydroxyl group, a halogen atom, or an alkyl group having 1 to 3 carbon atoms. Examples of the fatty acid include 12-hydroxystearic acid, stearic acid, myristic acid, montanic acid, and palmitic acid. From the perspective of significantly achieving the effects of the present invention, 12-hydroxystearic acid is preferred.

Commercially available polyester resins can be used. Examples of commercially available polyester resins include "UE-3980" manufactured by Unitika, "XA-0653" manufactured by Unitika, and "PA-111" manufactured by Ajinomoto Fine-Techno.

Another suitable embodiment of component (E) is a polyurethane resin. Examples of the polyurethane resin include carboxyl-containing polyurethane resins, hydroxyl-containing polyurethane resins, epoxy-containing polyurethane resins, and (meth)acryl-containing polyurethane resins.

A commercially available polyurethane resin can be used. Examples of commercially available polyurethane resins include "AGKN-026" manufactured by Negami Industries, Ltd.

When component (E) contains a carboxyl group, the acid value of component (E) is preferably 10 mgKOH/g or higher, more preferably 20 mgKOH/g or higher, and more preferably 30 mgKOH/g or higher, and preferably 150 mgKOH/g or lower, more preferably 120 mgKOH/g or lower, and more preferably 100 mgKOH/g or lower, from the perspective of improving resolvability. The acid value can be calculated using the same method as for the acid value of component (A).

When component (E) contains a hydroxyl group, the hydroxyl value of component (E) is preferably 20 mgKOH/g or higher, more preferably 30 mgKOH/g or higher, more preferably 40 mgKOH/g or higher, preferably 450 mgKOH/g or lower, more preferably 200 mgKOH/g or lower, more preferably 150 mgKOH/g or lower, 120 mgKOH/g or lower, or 100 mgKOH/g or lower, from the perspective of improving analytical performance. The hydroxyl value can be calculated using the following method. First, accurately weigh 2 g of the resin, add 5 ml of an acetylation reagent (a 100 mL solution of pyridine in 25 g of acetic anhydride), and heat in an oil bath at 95-100°C for 1 hour. Then, add 1 mL of water, heat at 95-100°C for 10 minutes, and then add 5 mL of ethanol. Add a few drops of phenolphthalein solution as an indicator and titrate with 0.5 mol/L potassium hydroxide ethanol solution. The end point is when the indicator turns light red and lasts for about 30 seconds. Perform a blank test in the same way and calculate the hydroxyl value according to the following formula (2). Formula: B = {(a-b) × 28.05/(Wp × I)} + acid value A      ・・・(2) In the above formula (2), B represents the hydroxyl value [mgKOH/g], a represents the titration amount of the KOH solution in the blank test [mL], b represents the titration amount of the KOH solution when the sample is used [mL], Wp represents the mass of the measured resin solution [g], and I represents the ratio of the non-volatile components in the measured resin solution [mass %]. The acid value A is the acid value of the (E) component calculated by the same method as the acid value of the (A) component.

From the viewpoint of suppressing the formation of depressions originating from aggregates on the surface of the cured product after the roughening treatment and improving the peel strength, softness, and resolvability, the content of component (E) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, more preferably 0.5% by mass or more, 1% by mass or more, or 1.5% by mass or more, preferably 10% by mass or less, more preferably 8% by mass or less, and particularly preferably 5% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

When the content of component (A) is represented by a and the content of component (E) is represented by e, with the non-volatile components in the resin composition being 100% by mass, in order to significantly achieve the effects of the present invention, a/e is preferably 1 or greater, more preferably 1.5 or greater, more preferably 2 or greater, and preferably 30 or less, more preferably 25 or less, and even more preferably 10 or less.

When the content of component (D) is d and the content of component (E) is e, relative to 100% by mass of the non-volatile components in the resin composition, the ratio d/e is preferably 0.1 or greater, more preferably 0.5 or greater, more preferably 1 or greater, and preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less, in order to significantly achieve the effects of the present invention.

<(F) Reactive Diluent> The photosensitive resin composition may further contain a (F) reactive diluent as an optional component. However, components corresponding to components (A) to (E) are not included in component (F). The inclusion of component (F) enhances photoreactivity. Component (F) can be, for example, a photosensitive (meth)acrylate compound having one or more (meth)acryloyl groups per molecule that is liquid, solid, or semi-solid at room temperature. Room temperature refers to approximately 25°C.

Representative photosensitive (meth)acrylate compounds include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxybutyl acrylate, mono- or diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol, acrylamides such as N,N-dimethylacrylamide and N-hydroxymethylacrylamide, aminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate, trihydroxymethylpropane, Polyvalent acrylates of polyols such as pentaerythritol and dipentaerythritol, or adducts of these with ethylene oxide, propylene oxide, or ε-caprolactone; phenols such as phenoxy acrylate and phenoxyethyl acrylate; or acrylates such as adducts of these ethylene oxide or propylene oxide; epoxy acrylates derived from glycidyl ethers such as trihydroxymethylpropane triglycidyl ether; melamine acrylates; and/or methacrylates corresponding to the above acrylates. Among these, polyvalent acrylates or polyvalent methacrylates are preferred. For example, as trivalent acrylates or methacrylates, there can be cited trihydroxymethylpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trihydroxymethylpropane EO addition tri(meth)acrylate, glycerol PO addition tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, tetrafurfuryl alcohol oligo(meth)acrylate, ethyl carbitol oligo(meth)acrylate, 1,4-butanediol oligo(meth)acrylate, 1,6-hexanediol oligo(meth)acrylate, trihydroxymethylpropane oligo(meth)acrylate, pentaerythritol oligo(meth)acrylate, tetrahydroxymethylmethane tetra(meth)acrylate, dipentaerythritol oligo(meth)acrylate, Examples of the trivalent or higher valent acrylates or methacrylates include hexa(meth)acrylate, (meth)acrylate of N,N,N',N'-tetra(β-hydroxyethyl)ethylenediamine, and phosphate triester (meth)acrylates such as tris(2-(meth)acryloyloxyethyl)phosphate, tris(2-(meth)acryloyloxypropyl)phosphate, tris(3-(meth)acryloyloxypropyl)phosphate, tris(3-(meth)acryloyl-2-hydroxyoxypropyl)phosphate, di(3-(meth)acryloyl-2-hydroxyoxypropyl)(2-(meth)acryloyloxyethyl)phosphate, and (3-(meth)acryloyl-2-hydroxyoxypropyl)bis(2-(meth)acryloyloxyethyl)phosphate. Any one of these photosensitive (meth)acrylate compounds may be used alone, or two or more thereof may be used in combination.

From the viewpoint of promoting photocuring and suppressing adhesion during the production of a cured product, the content of component (F) when blended, relative to 100% by mass of the total solids content of the photosensitive resin composition, is preferably 1% by mass or more, more preferably 2% by mass or more, and more preferably 3% by mass or more, and preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 6% by mass or less.

<(G) Solvent> The photosensitive resin composition may further contain a (G) solvent as an optional component. The inclusion of a (G) solvent allows adjustment of the varnish viscosity. Examples of the (G) solvent include organic solvents.

Examples of the solvent (G) include ketones such as ethyl methyl ketone (MEK) and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as diethylene glycol monoethyl ether acetate, diethylene glycol ethyl ether acetate (EDGAc), methyl solvent, butyl solvent, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl solvent acetate, carbitol acetate, and diethylene glycol ethyl ether acetate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent oil. These solvents may be used alone or in combination of two or more. From the perspective of the coating properties of the photosensitive resin composition, the content of the solvent can be appropriately adjusted.

<(H) Other Additives> The photosensitive resin composition may further contain (H) other additives to the extent that the purpose of the present invention is not hindered. Other additives (H) that can be added include, for example, organic fillers, fine particles of melamine, organic bentonite, etc., colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, etc., polymerization inhibitors such as hydroquinone, phenothiazine, methyl hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, etc., thickeners such as bentonite and montmorillonite, polysilicone-based, fluorine-based, and vinyl resin-based defoaming agents, flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, antimony compounds, phosphorus compounds, aromatic condensed phosphates, halogen-containing condensed phosphates, and thermosetting resins such as phenolic hardeners and cyanate hardeners.

The photosensitive resin composition is prepared by mixing the aforementioned components (A) to (E) as essential components and appropriately mixing components (F) to (H) as optional components. The composition can be kneaded or stirred as needed using a three-roll mill, ball mill, bead mill, sand mixer, or other mixing method, or by stirring using a super mixer, planetary mixer, or other mixing method.

<Physical Properties and Applications of Photosensitive Resin Compositions> The cured product obtained by photocuring a photosensitive resin composition generally exhibits excellent resolving power (developability). This suppresses the formation of residue in unexposed areas. Furthermore, the via shape does not become an inverted pyramid or exhibit cracks. Evaluation of residue in unexposed areas and via shape can be performed using the methods described in the Examples below.

Cured products obtained by photocuring photosensitive resin compositions generally exhibit excellent resolving power. Consequently, they can form residue-free minimum pore diameters. The minimum pore diameter is preferably 60 μm or less, more preferably 45 μm or less, and even more preferably 40 μm or less. While the lower limit is not particularly limited, it can be set to 1 μm or greater. The minimum pore diameter can be measured using the methods described in the Examples below.

The cured product obtained by photocuring a photosensitive resin composition can improve the peel strength from the conductive layer formed by coating. Therefore, when this cured product is used to form an insulating layer, the resulting insulating layer has a high peel strength from the conductive layer. The peel strength is preferably 0.15 kgf/cm or greater, more preferably 0.20 kgf/cm or greater, and particularly preferably 0.3 kgf/cm or greater. The upper limit of the peel strength is not particularly limited, but can be, for example, 10.0 kgf/cm or less. The peel strength can be measured according to the method described in the Examples below.

A cured product obtained by photocuring a photosensitive resin composition can suppress concavities caused by aggregates that form on the surface of the cured product after a roughening treatment (desmearing treatment). Consequently, an insulating layer or solder resist can be obtained that suppresses concavities caused by aggregates that form on the surface. Specifically, the concavities described above are those with a width of 2 μm or greater and a depth of 1 μm or greater. These concavities can be measured using the methods described in the Examples below.

Photosensitive resin compositions generally exhibit excellent flexibility. Therefore, even when stress is applied, they can suppress the scattering of the resin and the formation of cracks.

The use of the photosensitive resin composition of the present invention is not particularly limited, and can be widely used in applications requiring a photosensitive resin composition, such as photosensitive films, insulating resin sheets such as prepregs, circuit boards (for laminated boards, multilayer printed wiring boards, etc.), solder resists, underfill materials, die attach materials, semiconductor encapsulants, via-filling resins, and component embedding resins. Among them, the photosensitive resin composition is suitable as an insulating layer for a printed wiring board (a printed wiring board using a cured product of the photosensitive resin composition as the insulating layer), a photosensitive resin composition for an interlayer insulating layer (a printed wiring board using a cured product of the photosensitive resin composition as the interlayer insulating layer), a photosensitive resin composition for plating formation (a printed wiring board having a plating formed on a cured product of the photosensitive resin composition), and a photosensitive resin composition for solder resist (a printed wiring board using a cured product of the photosensitive resin composition as the solder resist).

[Photosensitive Film] The photosensitive film comprises a support and a photosensitive resin composition layer disposed on the support. The photosensitive resin composition layer comprises the photosensitive resin composition of the present invention.

Examples of the support include polyethylene terephthalate film, polyethylene naphthalate film, polypropylene film, polyethylene film, polyvinyl alcohol film, triacetate film, and the like, with polyethylene terephthalate film being particularly preferred.

Examples of commercially available supports include, but are not limited to, polypropylene films such as "Arufun MA-410" and "E-200C" manufactured by Oji Paper Co., Ltd., and polyethylene terephthalate films such as the PS series product "PS-25" manufactured by Teijin. To facilitate removal of these supports, it is preferable to apply a release agent such as silicone coating to the surface. The thickness of the support is preferably in the range of 5 μm to 50 μm, and more preferably in the range of 10 μm to 25 μm. A thickness of 5μm or greater prevents support tearing during support peeling prior to development, while a thickness of 50μm or less improves resolution during exposure from the support. Furthermore, a support with low fisheye is preferred. Fisheye refers to the intrusion of foreign matter, undissolved matter, and oxidative degradation products into the film during the process of heat-melting the material and then producing the film through kneading, extrusion, biaxial stretching, casting, and other methods.

Furthermore, to reduce light scattering caused by active energy rays such as ultraviolet light during exposure, the support preferably has excellent transparency. Specifically, a support preferably has a haze value (haze value as specified in JIS K6714), which serves as an indicator of transparency, of 0.1 to 5. Furthermore, the photosensitive resin composition layer can be protected by a protective film.

The protective film protects the photosensitive resin layer side of the photosensitive film, preventing dust and other substances from adhering to or damaging the surface of the photosensitive resin layer. The protective film can be made of the same material as the support member described above. The thickness of the protective film is not particularly limited, but is preferably in the range of 1μm to 40μm, more preferably in the range of 5μm to 30μm, and even more preferably in the range of 10μm to 30μm. A thickness of 1μm or greater improves the handling of the protective film, while a thickness of 40μm or less tends to be less expensive. In the protective film, it is preferred that the adhesion between the photosensitive resin composition layer and the protective film is smaller than the adhesion between the photosensitive resin composition layer and the support.

From the perspective of improving operability and suppressing a decrease in sensitivity and resolution within the photosensitive resin composition layer, the thickness of the photosensitive resin composition layer is preferably 10 μm or greater, more preferably 15 μm or greater, more preferably 20 μm or greater, preferably 30 μm or less, more preferably 28 μm or less, and even more preferably 25 μm or less.

For example, a photosensitive film can be produced by dissolving a resin composition in an organic solvent to prepare a resin varnish, applying the resin varnish to a support using a die coater, and then drying the resin composition layer. The organic solvent used can be the same as that of component (G) above.

Examples of methods for applying resin varnish include gravure coating, micro-gravure coating, reverse coating, reverse kiss coating, die coating, slit coating, lip coating, comma coating, doctor blade coating, roll coating, blade coating, curtain coating, chamber gravure coating, slit coating, spray coating, and dip coating.

Resin varnish can be applied in multiple passes, a single application, or a combination of different methods. Die-type coating is preferred, as it provides excellent uniformity. Furthermore, to prevent foreign matter from entering, the coating process is best performed in a cleanroom or other environment with minimal foreign matter buildup.

The drying temperature varies depending on the curability of the photosensitive resin composition and the amount of component (G) in the resin varnish, and can be between 80°C and 120°C. However, from the perspective of obtaining a cured product with excellent undercut resistance, the maximum drying temperature is preferably 105°C or higher, more preferably 110°C or higher. While the lower limit of the maximum temperature is not particularly limited, it is preferably 135°C or lower, more preferably 130°C or lower.

The drying time varies depending on the curability of the photosensitive resin composition and the amount of component (G) in the resin varnish, but is preferably 6 minutes or longer, preferably 30 minutes or shorter, and even more preferably 20 minutes or shorter. Here, the drying time refers to the time from when the drying temperature reaches 80°C.

The residual amount of component (G) in the photosensitive resin composition layer is preferably set to 5% by mass or less, and more preferably 2% by mass or less, relative to the total amount of the photosensitive resin composition layer. Suitable drying conditions can be determined by a person skilled in the art through simple experiments.

Because the photosensitive film includes a photosensitive resin composition layer containing the photosensitive resin composition of the present invention, it exhibits excellent flexibility. For example, the photosensitive film can be wound around a 3-inch core and cut using a roller. This can suppress the occurrence of cracks in the photosensitive film.

[Printed Wiring Board] The printed wiring board of the present invention includes an insulating layer formed from a cured product of the photosensitive resin composition of the present invention. This insulating layer is preferably used as a solder resist or an interlayer insulating layer.

Specifically, the printed wiring board of the present invention can be manufactured using the above-mentioned photosensitive film. The following describes an example in which the insulating layer is a solder resist.

<Coating and Drying Step> When a resin varnish containing a photosensitive resin composition is directly applied to a circuit board, component (G) is dried and volatilized, forming a photosensitive resin composition layer on the circuit board.

Examples of circuit substrates include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The term "circuit substrate" herein refers to a substrate having a patterned conductive layer (circuit) formed on one or both sides of a supporting substrate such as the above. Furthermore, a multi-layer printed wiring board in which a conductive layer and an insulating layer are alternately stacked is also included in the term "circuit substrate" if the outermost layer of the multi-layer printed wiring board has a patterned conductive layer (circuit) on one or both sides. Furthermore, the surface of the conductive layer may be roughened in advance by blackening, copper etching, or the like.

While screen printing is the most common coating method, any other method that achieves uniform coating can be used. Examples include spray coating, hot melt coating, rod coating, applicator coating, doctor blade coating, blade coating, air knife coating, curtain coating, roll coating, gravure coating, lithographic printing, dip coating, brush coating, and other common coating methods. After coating, drying is performed in a hot air oven or far infrared oven as needed. The optimal drying conditions are 80°C to 120°C for 3 to 13 minutes. In this manner, a photosensitive composition layer is formed on the circuit substrate.

<Lamination Step> On the other hand, when using a photosensitive film, a vacuum laminator is used to laminate the photosensitive resin composition layer to one or both sides of the circuit board. During the lamination step, if the photosensitive film has a protective film, after removing the protective film, the photosensitive film and circuit board are preheated as needed, and the photosensitive resin composition layer is pressed and heated while being bonded to the circuit board. For photosensitive films, vacuum lamination under reduced pressure is suitable.

The lamination process conditions are not particularly limited. For example, the lamination temperature (lamination temperature) is preferably set to 70°C to 140°C, the lamination pressure is preferably set to 1 kgf/ ^cm² to 11 kgf/ ^cm² (9.8× ^10⁴ N/ ^m² to 107.9× ^10⁴ N/ ^m² ), the lamination time is preferably set to 5 seconds to 300 seconds, and the lamination is preferably performed under reduced pressure at an air pressure of 20 mmHg (26.7 hPa) or less. The lamination process can be performed in batches or continuously using a roll. Vacuum lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum laminator manufactured by Nikko Materials, a vacuum pressure laminator manufactured by Meiki Manufacturing, a roll-type dry coater manufactured by Hitachi Industries, and a vacuum laminator manufactured by Hitachi AIC.

<Exposure Step> After a photosensitive resin composition layer is formed on the circuit board through a coating and drying step or a lamination step, an exposure step is performed to irradiate a designated portion of the photosensitive resin composition layer with active light through a mask pattern, thereby photocuring the exposed portion of the photosensitive resin composition layer. Examples of active light include ultraviolet light, visible light, electron beams, and X-rays, with ultraviolet light being particularly preferred. The UV exposure dose is generally between 10mJ/ ^cm² and 1000mJ/ ^cm² . Exposure methods include contact exposure, which involves contacting the mask pattern to the printed wiring board, and non-contact exposure, which involves using parallel light without contact. Either method can be used. Furthermore, when a support is present on the photosensitive resin composition layer, exposure can be performed from above the support, or exposure can be performed after the support is peeled off.

Because the solder resist uses the photosensitive resin composition of the present invention, it has excellent developability. Therefore, the exposure pattern used in the mask pattern can have a ratio (L/S) of circuit width (line width; L) to width between circuits (spacing; S) of 100μm/100μm or less (i.e., wiring pitch 200μm or less), L/S = 80μm/80μm or less (wiring pitch 160μm or less), L/S = 70μm/70μm or less (wiring pitch 140μm or less), or L/S = 60μm/60μm or less (wiring pitch 120μm or less). Furthermore, the pitch does not need to be uniform across the entire circuit board.

Because the solder resist uses the photosensitive resin composition of the present invention, it exhibits excellent developability. Therefore, the hole diameter can be preferably set to 100 μm or less, more preferably 90 μm or less, and even more preferably 80 μm or less. While the lower limit is not particularly limited, it can be set to 1 μm or more, 10 μm or more, and so on.

<Development Step> After the exposure step, if a support exists on the photosensitive resin composition layer, the support is removed. The uncured portions (unexposed areas) are then removed by wet or dry development, followed by development to form a pattern.

In the case of wet development, safe, stable, and easy-to-use developers such as alkaline aqueous solutions, water-based developers, and organic solvents can be used. Development using alkaline aqueous solutions is preferred. Furthermore, well-known methods such as spraying, shaking and dipping, brushing, and patting can be appropriately employed as developing methods.

Examples of alkaline aqueous solutions used as developers include aqueous solutions of alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; carbonates such as sodium carbonate and sodium bicarbonate; or bicarbonates; alkali metal phosphates such as sodium phosphate and potassium phosphate; alkali metal pyrrolate salts such as sodium pyrroline and potassium pyrroline; or aqueous solutions of organic bases such as tetramethylammonium hydroxide that do not contain metal ions. An aqueous solution of tetramethylammonium hydroxide (TMAH) is preferred because it does not contain metal ions and does not affect semiconductor chips.

To enhance the developing effect, surfactants, defoaming agents, and the like may be added to the alkaline aqueous solution. The pH of the alkaline aqueous solution is preferably in the range of 8-12, and more preferably in the range of 9-11. Furthermore, the alkaline concentration of the alkaline aqueous solution is preferably set to 0.1% by mass to 10% by mass. The temperature of the alkaline aqueous solution can be appropriately selected based on the developing properties of the photosensitive resin composition layer, preferably between 20°C and 50°C.

Organic solvents used as developers include acetone, ethyl acetate, alkoxyethanols having an alkoxy group with 1 to 4 carbon atoms, ethanol, isopropyl alcohol, butanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether.

The concentration of such organic solvents is preferably between 2% and 90% by mass relative to the total developer volume. Furthermore, the temperature of such organic solvents can be adjusted to suit the developing properties. Furthermore, such organic solvents can be used alone or in combination of two or more. Examples of organic solvent-based developers that can be used alone include 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone.

During pattern formation, two or more of the above development methods can be used in combination, depending on the need. Development methods include immersion, stirring, spraying, high-pressure spraying, brushing, and tapping. High-pressure spraying is suitable for improving resolution. When using the spraying method, the ideal spray pressure is 0.05MPa to 0.3MPa.

<Thermal Curing (Post-Bake) Step> After the development step, a thermal curing (post-bake) step is performed to form the solder resist. Examples of post-bake steps include UV irradiation using a high-pressure mercury lamp or heating in a clean oven. The UV irradiation dose can be adjusted as needed, for example, between 0.05 J/ ^cm² and 10 J/ ^cm² . Furthermore, the heating conditions can be appropriately selected according to the type and content of the resin components in the photosensitive resin composition. Preferably, the heating conditions are in the range of 150°C to 220°C for 20 minutes to 180 minutes, and more preferably, in the range of 160°C to 200°C for 30 minutes to 120 minutes.

<Other Steps> After forming the solder mask, the printed wiring board process may further include a hole opening step and a desmearing step. These steps can be performed using various methods known to those skilled in the art for printed wiring board manufacturing.

After forming the solder resist, a hole drilling step is performed on the solder resist formed on the circuit board to form through-holes or through-holes as desired. This hole drilling step can be performed by known methods such as drilling, laser, and plasma, or a combination of these methods as needed. Laser drilling using a CO2 laser or YAG laser is preferred.

The debonding step is a treatment step for removing glue residue. Resin residue (glue residue) is typically found inside the opening formed during the drilling step. Because this residue can cause poor electrical connections, this step is used to remove it.

Desmear treatment can be performed by dry desmear treatment, wet desmear treatment, or a combination thereof.

Examples of dry desmear treatment include desmear treatment using plasma. Desmear treatment using plasma can be performed using commercially available plasma desmear treatment equipment. Examples of commercially available plasma desmear treatment equipment suitable for printed wiring board manufacturing include the microwave plasma equipment manufactured by Nissin Corporation and the atmospheric pressure plasma etching equipment manufactured by Sekisui Chemical Industry Co., Ltd.

Examples of wet desmear treatments include desmear treatments using an oxidizing solution. When using an oxidizing solution for desmear treatment, it is preferred to sequentially perform a swelling treatment using a swelling solution, an oxidation treatment using an oxidizing solution, and a neutralization treatment using a neutralizing solution. Examples of swelling solutions include "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Japan. The swelling treatment is preferably performed by immersing the substrate, with through-holes formed thereon, in a swelling solution heated to 60°C to 80°C for 5 to 10 minutes. An alkaline permanganic acid aqueous solution is preferred as the oxidizing solution. For example, a solution obtained by dissolving potassium permanganate or sodium permanganate in an aqueous sodium hydroxide solution can be used. Oxidation treatment using an oxidizing solution is preferably performed by immersing the substrate, after swelling treatment, in an oxidizing solution heated to 60°C to 80°C for 10 to 30 minutes. Commercially available alkaline permanganic acid aqueous solutions include "Concentrate Compact CP" and "Dosing Solution Securiganth P" manufactured by Atotech Japan. Neutralization treatment using a neutralizing solution is preferably performed by immersing the substrate, after oxidation treatment, in a neutralizing solution at 30°C to 50°C for 3 to 10 minutes. An acidic aqueous solution is preferably used as the neutralizing solution. An example of a commercially available product is "Reduction solution Securiganth P" manufactured by Atotech Japan.

When combining dry desmear treatment with wet desmear treatment, you can perform dry desmear treatment first or wet desmear treatment first.

When the insulating layer is used as an interlayer insulation layer, the same steps as the solder resist can be performed. Alternatively, the hole opening step, desmearing step, and coating step can be performed after the heat curing step.

The plating step forms a conductive layer on the insulating layer. The conductive layer can be formed by combining electroless and electrolytic plating. Alternatively, by forming a plating resist with a pattern opposite to that of the conductive layer, the conductive layer can be formed solely by electroless plating. Subsequent patterning methods, such as subtractive and semi-additive processes, are well known to those skilled in the art.

[Semiconductor Device] The semiconductor device of the present invention includes a printed wiring board. The semiconductor device of the present invention can be manufactured using the printed wiring board of the present invention.

Semiconductor devices are used in various electronic products (such as computers, mobile phones, digital cameras, and televisions) and vehicles (such as motorcycles, cars, trams, ships, and airplanes).

The semiconductor device of the present invention can be manufactured by mounting a component (semiconductor chip) on a conductive portion of a printed wiring board. "Conductive portion" refers to a portion of a printed wiring board that transmits electrical signals, and this portion can be either surface or embedded. Furthermore, the semiconductor chip is not particularly limited, as long as it is an electrical circuit element made of semiconductors.

The semiconductor chip mounting method used in manufacturing the semiconductor device of the present invention is not particularly limited as long as the semiconductor chip can effectively function. Specific examples include wire bonding mounting, flip-chip mounting, mounting using a bumpless build-up layer (BBUL), mounting using anisotropic conductive film (ACF), and mounting using a non-conductive film (NCF). Here, "mounting using a bumpless build-up layer (BBUL)" refers to a mounting method in which the semiconductor chip is directly embedded in a recessed portion of a printed wiring board and connected to wiring on the printed wiring board. [Examples]

The present invention is specifically described below by way of examples, but the present invention is not limited to these examples. In the following descriptions, "parts" and "%" representing amounts, unless otherwise specified, represent "parts by mass" and "% by mass," respectively.

-Measurement of Weight Average Molecular Weight of Component (E)- The weight average molecular weight of each component (E) is the polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

-Measurement of the Glass Transition Temperature (Tg) of the (E) Component- The glass transition temperature of each (E) component was measured using differential scanning calorimetry at a heating rate of 5°C/min in accordance with JIS K 7121.

(Synthesis Example 1: Synthesis of Resin (A-1)) 162 parts of 1,1'-bis(2,7-diglycidyloxynaphthyl)methane ("EXA-4700", manufactured by Dainippon Ink & Chemicals Co., Ltd.) with an epoxy equivalent of 162 g/eq. were placed in a flask equipped with a gas inlet, stirrer, cooling tube, and thermometer. 340 parts of carbitol acetate was added and dissolved under heating. 0.46 parts of hydroquinone and 1 part of triphenylphosphine were then added. The mixture was heated to 95-105°C, and 72 parts of acrylic acid was slowly added dropwise. The mixture was reacted for 16 hours. The reaction product was cooled to 80-90°C, and 80 parts of tetrahydrophthalic anhydride was added. The reaction was allowed to react for 8 hours, followed by cooling. In this manner, a resin solution with a solid acid value of 90 mgKOH/g (non-volatile content 70%) was obtained.

(Synthesis Example 2: Synthesis of Resin (E-1)) A reaction flask equipped with a thermometer, stirrer, nitrogen inlet, reflux tube, water separator, and pressure relief port was charged with 100 parts of 12-hydroxystearic acid (trade name: 12-hydro Acid, manufactured by Kokura Synthetic Industries Co., Ltd.). The reaction was allowed to proceed at 150°C for 3 hours under a nitrogen atmosphere. The mixture was then heated at 200°C for 6 hours under reduced pressure. The mixture was then cooled to room temperature. In this manner, Resin (E-1) was obtained, having an acid value of 32 mgKOH/g, a weight-average molecular weight of 6000, and a Tg of -58°C.

<Examples 1-14, Comparative Examples 1-4> The components were blended in the proportions shown in the table below and a high-speed rotary mixer was used to prepare a resin varnish.

Next, a PET film (Toray Industries, Inc., "Lumirror T6AM," 38 μm thick, 130°C softening point, "Release PET") treated with an alkyd resin release agent (LINTEC, Inc., "AL-5") was prepared as a support. Using a die coater, a resin varnish was evenly applied to the release PET, resulting in a 20 μm thick photosensitive resin composition layer after drying. The film was then dried at 80°C to 110°C for 5 minutes, yielding a photosensitive film with a photosensitive resin composition layer on the release PET.

<Evaluation of Flexibility> The photosensitive resin composition layer of the photosensitive films produced in Examples and Comparative Examples was cut into 5 cm straight lines at three locations using a razor blade. The presence of resin scattering and cracks was visually evaluated. Furthermore, the presence of cracks at the three locations, when the film was bent 180°, was visually confirmed. ∘: No scattering or cracking of the photosensitive resin composition was observed at any of the three locations. ∘: No scattering or cracking of the photosensitive resin composition was observed at any of the three locations. ∘: No scattering or cracking of the photosensitive resin composition was observed at any of the three locations. ∘: No scattering or cracking of the photosensitive resin composition was observed at all three locations.

<Analytical Evaluation> (Formation of Evaluation Laminate A) The copper layer of a glass epoxy substrate (copper-clad laminate) with a patterned 18μm copper layer was roughened by treatment with a surface treatment agent containing an organic acid (CZ8100, manufactured by MEC). Next, a photosensitive resin composition layer of the photosensitive film obtained in the Examples and Comparative Examples was placed in contact with the surface of the copper circuit and laminated using a vacuum laminator (VP160, manufactured by Nikko Morton Co., Ltd.) to form a laminate comprising the copper-clad laminate, the photosensitive resin composition layer, and the support body laminated in this order. The pressing conditions were set as 30 seconds of vacuuming, a temperature of 80°C, a pressure of 0.7 MPa, and a pressing time of 30 seconds. The laminate was then left at room temperature for at least 30 minutes. UV exposure was then performed from above the laminate's support using a patterning device with a circular hole pattern. The exposure pattern used was a quartz glass mask capable of creating circular holes with openings of 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, and 100μm, as well as a 1cm x 2cm square. After 30 minutes at room temperature, the support was removed from the laminate. The entire surface of the photosensitive resin composition layer on the laminate was spray-developed using a 1% by mass sodium carbonate aqueous solution at 30°C as a developer at a spray pressure of 0.2 MPa for 2 minutes. After spray development, the laminate was irradiated with UV light at 1 J/ ^cm² and then heated at 180°C for 30 minutes to form an insulating layer with openings. This laminate was designated Evaluation Laminate A.

(Analytical Evaluation) A 1 cm x 2 cm section of laminate A was visually inspected for unexposed areas. A score of 0 was assigned if no resin remained in the unexposed area; a score of × was assigned if resin was visually visible. The formed holes were then observed using a SEM (1000x magnification) to measure the minimum hole diameter without any residue. The hole shape was evaluated according to the following criteria: ○: The hole did not form an inverted cone and had no cracks. ×: The hole formed an inverted cone or had cracks on the hole wall.

<Evaluation of Desmear and Measurement of Peel Strength After Desmear Treatment> (Formation of Evaluation Laminates C and D) The copper layer of a glass epoxy substrate (copper-clad laminate) with an 18μm-thick copper layer was roughened by treatment with a surface treatment agent containing an organic acid (CZ8100, manufactured by MEC). Next, the photosensitive resin composition layer of the photosensitive film obtained in the Examples and Comparative Examples was positioned so that it contacted the surface of the copper circuit. Lamination was performed using a vacuum laminator (Nikko Morton, VP160) to form a laminate consisting of the copper-clad laminate, the photosensitive resin composition layer, and the support in this order. Lamination conditions were: vacuum time of 30 seconds, lamination temperature of 80°C, lamination pressure of 0.7 MPa, and lamination time of 30 seconds.

The laminate was allowed to stand at room temperature for at least 30 minutes. The laminate was then irradiated with UV light at 100 mJ/ ^cm² from above its support. After standing at room temperature for 30 minutes, the support was removed from the laminate. The entire surface of the photosensitive resin composition layer on the laminate board was spray-developed using a 1% by mass sodium carbonate aqueous solution at 30°C at a spray pressure of 0.2 MPa for 2 minutes. Following spray development, the laminate was irradiated with UV light at 1 J/ ^cm² and then heated at 180°C for 30 minutes to form an insulating layer. This is referred to as evaluation layer B.

As a roughening treatment for the insulating layer of evaluation laminate B, desmearing treatment was performed as follows. The samples were immersed in a swelling solution (Atotech Japan's "Swelling Dip Securiganth P," an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60°C for 2 minutes. Next, they were immersed in an oxidizing solution (Atotech Japan's "Concentrate Compact CP," an aqueous solution of approximately 6% potassium permanganate and approximately 4% sodium hydroxide) at 80°C for 3 minutes. Finally, they were immersed in a neutralizing solution (Atotech Japan's "Reduction Solution Securiganth P," an aqueous solution of sulfuric acid) at 40°C for 5 minutes, followed by drying at 80°C for 15 minutes. The resulting substrate is referred to as evaluation laminate C.

A conductive layer was formed on the roughened surface of the insulating layer using a semi-additive method. Specifically, the roughened substrate was immersed in an electroless plating solution containing PdCl₂ at 40°C for 5 minutes, then immersed in an electroless copper plating solution at 25°C for 20 minutes. Next, the substrate was heated at 150°C for 30 minutes and annealed. A 30μm-thick conductive layer was then electrolytically plated with copper sulfate, followed by annealing at 200°C for 60 minutes. The resulting substrate is referred to as evaluation laminate D.

(Evaluation of Desmear after Desmear Treatment) The roughened surface of the insulating layer of the evaluation substrate laminate C after desmear treatment was observed using a SEM (1000x magnification) and evaluated according to the following criteria. ○: No desmears larger than 2 μm in width and larger than 1 μm in depth were observed. ×: One or more desmears larger than 2 μm in width and larger than 1 μm in depth were observed.

(Peel Strength Measurement) The peel strength of the coated conductive layer and the peel strength between the insulating layer and the conductive layer were measured for evaluation laminate D in accordance with Japanese Industrial Standards (JIS C6481). Specifically, a 10 mm wide and 100 mm long section was cut in the conductive layer of evaluation laminate C. This section was peeled off and clamped with a clip. The load (kgf/cm) applied when the sheet was peeled vertically for 35 mm at a speed of 50 mm/min at room temperature was measured to determine the peel strength. Measurements were performed using a tensile testing machine (TSE "AC-50C-SL"). The peel strength was evaluated based on the following criteria. ◎: Peel strength 0.30 kgf/cm or greater ○: Peel strength 0.20 kgf/cm or greater but less than 0.30 kgf/cm △: Peel strength 0.15 kgf/cm or greater but less than 0.20 kgf/cm ×: Peel strength less than 0.15 kgf/cm

Abbreviations in the table are as follows. (A) Components Synthesis Example 1: Resin (A-1) synthesized in Synthesis Example 1. ZFR-1491H: Bisphenol F epoxy acrylate (manufactured by Nippon Kayaku Co., Ltd., acid value 99 mgKOH/g, solids concentration approximately 70%). ZAR-2000: Bisphenol A epoxy acrylate (manufactured by Nippon Kayaku Co., Ltd., acid value 99 mgKOH/g, solids concentration approximately 70%). (B) Components SC2050: 100 parts by mass of fused silica (manufactured by Admatechs, average particle size 0.5 μm) surface-treated with 0.5 parts by mass of aminosilane (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573"). (C) Components Omnirad TPO: Diphenyl (2,4,6-trimethylbenzyl) phosphine oxide, manufactured by IGM Resins Co., Ltd. (D) Components NC3000L: Biphenyl-type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent weight approximately 271 g/eq.) ELM-434VL: Tetraglycidyl diaminodiphenylmethane-type epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., epoxy equivalent weight approximately 115 g/eq.) (E) Components CB-3060: Polyfunctional carboxyl-containing acrylic polymer (manufactured by Soken Chemical Co., Ltd., 2EHA backbone, weight-average molecular weight 3000, acid value 60 mgKOH/g, Tg: -70°C)・CB-3098: Polyfunctional carboxyl-containing acrylic polymer (Soken Chemical Co., Ltd., 2EHA backbone, weight-average molecular weight 3000, acid value 98 mgKOH/g, Tg: -70°C). ・CBB-3098: Polyfunctional carboxyl-containing acrylic polymer (Soken Chemical Co., Ltd., BA backbone, weight-average molecular weight 3000, acid value 98 mgKOH/g, Tg: -54°C). ・UT-1001: Hydroxyl-containing acrylic polymer (Soken Chemical Co., Ltd., 2EHA backbone, weight-average molecular weight 3000, hydroxyl value 57 mgKOH/g, Tg: -70°C). ・UE-3980: Polyester (Unitika, Ltd., weight-average molecular weight 8000, Tg: 58°C).・XA-0653: Polyester (manufactured by Unitika, weight-average molecular weight 5000, acid value 20 mgKOH/g, Tg: 56°C). ・Synthesis Example 2: Component (E-1) synthesized in Synthesis Example 2. ・AGKN-026: Polyurethane (manufactured by Negami Industries, Ltd., weight-average molecular weight 3000, Tg: -40°C). ・BPX-003: Hydroxyl-containing acrylic polymer (manufactured by Negami Industries, Ltd., weight-average molecular weight 3000, hydroxyl value 48 mgKOH/g, Tg: -63°C). Component (F) ・DPHA: Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., acrylic acid equivalent approximately 96 g/eq.). (G) Components ・EDGAc: Ethyl diglycol acetate ・MEK: Methyl ethyl ketone (H) Components ・AB-6: Polybutyl acrylate containing a methacryloyl group at one end (manufactured by Toagosei Co., Ltd., weight-average molecular weight 13,000, Tg: -55°C) ・UN-7600: Polyurethane (manufactured by Negami Industries, Ltd., weight-average molecular weight 11,500, Tg: -41°C) ・US-1071: Carboxyl-containing acrylic polymer (manufactured by Seikyo PMC Co., Ltd., weight-average molecular weight 9,500, acid value 75 mgKOH/g, Tg: 104°C) (B) Component Content: Content of component (B) based on the total solids content of the photosensitive resin composition being 100% by mass Content of component (E): The content of component (E) when the solid content of the photosensitive resin composition is set to 100% by mass.

As shown in the table above, Examples 1 to 14 exhibited flexibility, resolvability, and high coating adhesion, while also exhibiting no agglomerates or depressions after deslagging.

On the other hand, it can be seen that the plating peel strength of Comparative Example 1, which does not contain component (E), is lower than that of Examples 1-14. Furthermore, Comparative Examples 2 and 3, which use polymers with a weight-average molecular weight of 10,000 or greater, have high plating peel strengths but exhibit agglomerates or depressions after desmearing. Furthermore, Comparative Example 4, which uses a polymer component with a Tg higher than 65°C, exhibits low plating peel strength and exhibits agglomerates or depressions after desmearing.

In each example, even when components (F) to (G) were not contained, the results were found to be similar to those of the above examples, although the extent of the effects varied.

Claims (12)

A photosensitive resin composition comprising: (A) a resin containing ethylenically unsaturated groups and carboxyl groups, (B) an inorganic filler, (C) a photopolymerization initiator, (D) an epoxy resin, and (E) a high molecular weight component selected from one or more resins selected from (meth)acrylic resins, polyester resins, polyurethane resins, polyether resins, and polyolefin resins, wherein (E) has a glass transition temperature of 65°C or lower and a weight-average molecular weight of 1,000 or higher and less than 10,000. The photosensitive resin composition of claim 1, wherein the content of component (B) is 50% by mass or more and 85% by mass or less, based on 100% by mass of the non-volatile components of the photosensitive resin composition. The photosensitive resin composition of claim 1, wherein the component (E) has one or more groups selected from the group consisting of a carboxyl group, a hydroxyl group, an epoxy group, and a (meth)acryloyl group. The photosensitive resin composition of claim 1, wherein component (A) has a naphthalene skeleton. The photosensitive resin composition of claim 1, wherein component (A) is an epoxy (meth)acrylate containing an acid-modified naphthalene skeleton. The photosensitive resin composition of claim 1, wherein component (D) contains at least one of a biphenyl-type epoxy resin and a glycidylamine-type epoxy resin. The photosensitive resin composition of claim 1, wherein component (B) comprises silicon dioxide. A photosensitive film comprising the photosensitive resin composition according to any one of claims 1 to 7. A photosensitive film with a support comprises a support and a photosensitive resin composition layer disposed on the support, wherein the photosensitive resin composition layer comprises the photosensitive resin composition of any one of claims 1 to 7. A printed wiring board comprising an insulating layer formed from a cured product of the photosensitive resin composition according to any one of claims 1 to 7. The printed wiring board of claim 10, wherein the insulating layer is a solder resist. A semiconductor device comprising the printed wiring board of claim 10 or 11.