JP5513711B2 - Photosensitive resin composition and cured product thereof - Google Patents

Description

  The present invention relates to a photosensitive resin composition suitable for forming a flexible cured film such as a solder resist and a resin insulating layer of a thin printed wiring board, particularly a flexible wiring board, which requires low warpage, and a cured product thereof. The present invention relates to a printed wiring board having a cured film.

Conventionally, flexible wiring boards use an insulating film with adhesive applied to a polyimide film called a coverlay, which is press punched and laminated, and then heat cured under pressure under pressure to form a circuit. As a cover layer on the surface of the flexible substrate. Since this cover lay is composed of a polyimide film as a base and a low shrinkage thermosetting resin as an adhesive layer, warping after lamination and after press curing is very small, and further reinforcement after that The warpage after board pasting, thermosetting, and reflow soldering for component mounting can be extremely reduced, and it is used in large quantities for flexible substrate applications.
However, since punching is performed with a press, fine processing is difficult, and the positioning accuracy is not good when laminating with a circuit board on which a circuit is formed.

On the other hand, an alkali-developable photosensitive resin composition and its dry film have been proposed as a photosensitive coverlay. For example, Patent Document 1 (Japanese Patent Laid-Open No. 2000-131636) discloses (a) two or more pieces. A compound having a hydroxyl group and one or more carboxyl groups, (b) a carboxyl group obtained by reacting a bifunctional or higher polyisocyanate having a 6-membered ring structure and (c) a (meth) acrylate having a hydroxyl group A photosensitive resin composition containing a urethane acrylate, a photopolymerization initiator, a diluent, and a bifunctional or higher functional epoxy resin has been proposed.
However, since it is a photo-curable and thermosetting composition, there is a problem that there is curing shrinkage due to crosslinking, and warping occurs after photo-curing and after heat-curing.

Furthermore, as a low warpage composition, Patent Document 2 (Japanese Patent Laid-Open No. 2005-10318) discloses an active energy ray-curable resin containing a carboxyl group-containing urethane-modified epoxy (meth) acrylate, one to one molecule. A photosensitive resin composition for use in a circuit board solder resist containing an active energy ray-curable unsaturated compound having two ethylenically unsaturated bonds, a photopolymerization initiator, a diluent and a thermosetting epoxy compound has been proposed. Patent Document 3 (WO 2004/079452) proposes a photosensitive resin composition containing an alkaline aqueous solution-soluble urethane resin, a photopolymerization initiator, and a reactive crosslinking agent. Furthermore, Patent Document 4 (Japanese Patent Laid-Open No. 2002-229201) discloses a photocuring component containing a urethane (meth) acrylate compound having a carboxyl group and a compound having an ethylenically unsaturated group other than this, and thermosetting. A photosensitive composition containing a resin, a photopolymerization initiator, and a thermal polymerization catalyst has been proposed.
These compositions have a sufficiently small warp after curing, but when actually applied to a flexible wiring board, there is a drawback that warp occurs due to post-heating by the reinforcing plate attaching process and heating at the time of component mounting. Had.

Furthermore, in recent years, laser direct exposure has attracted attention for the purpose of improving alignment accuracy. However, when the conventional photosensitive resin composition as described above is used, a large amount of exposure is required, and the exposure time is long. There is a problem that it takes.
JP 2000-131836 A (Claims) JP 2005-10318 A (Claims) WO 2004/079452 (Claims) JP 2002-229201 A (Claims)

The present invention has been made in order to solve the problems of the prior art as described above, and its main purpose is to generate warpage due to heating in the process of manufacturing a flexible substrate and its subsequent processes and component mounting processes. In addition, it is highly sensitive even when a small amount of photopolymerization initiator is added, laser direct exposure is possible, and adhesion to various substrates similar to conventional solder resist compositions, solder heat resistance Another object of the present invention is to provide a photosensitive resin composition capable of forming a cured film pattern excellent in various properties such as moisture resistance, chemical resistance and electrical insulation.
Furthermore, an object of the present invention is to obtain a cured product excellent in various properties as described above obtained by using such a photosensitive resin composition, and a print in which a cured film such as a solder resist is formed by the cured product. It is providing a wiring board, especially a flexible printed wiring board.

（式中、Ｒ^１は、水素原子、フェニル基（炭素数１〜６のアルキル基、フェニル基、もしくはハロゲン原子で置換されていてもよい）、炭素数１〜２０のアルキル基（１個以上の水酸基で置換されていてもよく、アルキル鎖の中間に１個以上の酸素原子を有していてもよい）、炭素数５〜８のシクロアルキル基、炭素数２〜２０のアルカノイル基又はベンゾイル基（炭素数が１〜６のアルキル基もしくはフェニル基で置換されていてもよい）を表し、Ｒ^２は、フェニル基（炭素数１〜６のアルキル基、フェニル基もしくはハロゲン原子で置換されていてもよい）、炭素数１〜２０のアルキル基（１個以上の水酸基で置換されていてもよく、アルキル鎖の中間に１個以上の酸素原子を有していてもよい）、炭素数５〜８のシクロアルキル基、炭素数２〜２０のアルカノイル基又はベンゾイル基（炭素数が１〜６のアルキル基もしくはフェニル基で置換されていてもよい）を表す。） To achieve the above object, according to the present invention, (A) a bisphenol A, bisphenol F, biphenyl, have a bixylenol skeleton or structure is its water添骨price, and carboxyl group-containing resin having a urethane structure, (B) Developed with a dilute alkaline aqueous solution containing an oxime ester photopolymerization initiator having a group represented by the following general formula (I), and (C) a compound having two or more ethylenically unsaturated groups in the molecule It is a possible composition, Comprising: The said oxime ester system photoinitiator (B) is contained in the ratio of 0.1-1.5 mass part with respect to 100 mass parts of said carboxyl group-containing resin (A). A photosensitive resin composition is provided.

(In the formula, R ¹ represents a hydrogen atom, a phenyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group, or a halogen atom), an alkyl group having 1 to 20 carbon atoms (one or more). Or may have one or more oxygen atoms in the middle of the alkyl chain), a cycloalkyl group having 5 to 8 carbon atoms, an alkanoyl group having 2 to 20 carbon atoms, or benzoyl. Represents a group (which may be substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group), and R ² is a phenyl group (substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group or a halogen atom). Or an alkyl group having 1 to 20 carbon atoms (which may be substituted with one or more hydroxyl groups, and may have one or more oxygen atoms in the middle of the alkyl chain), carbon number 5 ˜8 cycloalkyl groups, Represents an alkanoyl group or a benzoyl group prime 2-20 (carbon atoms may be substituted with 1-6 alkyl or phenyl group).)

Before SL carboxyl group-containing resin (A), from the viewpoint of low warpage, bisphenol A, bisphenol F, biphenyl, bixylenol skeleton or a resin having a structure which is a water添骨price or a resin having a urethane structure. The carboxyl group-containing resin (A) is preferably a photosensitive resin having two or more radically polymerizable unsaturated double bonds from the viewpoint of photocurability. Furthermore, the photosensitive resin composition preferably has an absorbance at 355 nm of the dried coating film in the range of 0.3 to 1.2 at a dry film thickness of 25 μm. Moreover, it is preferable that the photosensitive resin composition of this invention contains a thermosetting component (D) from a viewpoint of characteristic improvement, such as the heat resistance of a cured film.
The photosensitive resin composition may be in a liquid form or a dry film form.

  Furthermore, according to the present invention, a cured product obtained by photocuring the photosensitive resin composition or its dry film on copper, particularly a cured product obtained by photocuring with a laser oscillation light source, and a maximum wavelength. Is printed with a laser beam of 350 to 410 nm, and then a printed wiring board having a cured film obtained by heat curing is provided.

  The photosensitive resin composition of the present invention comprises the above general formula (I) as a photopolymerization initiator blended together with a carboxyl group-containing resin (A) and a compound (C) having two or more ethylenically unsaturated groups in the molecule. ) Having an oxime ester-based photopolymerization initiator (B) having a group represented by), it is possible to suppress the occurrence of warpage due to heating in the process of producing a flexible substrate and the subsequent process and component mounting process, and the above carboxyl Even if the oxime ester photopolymerization initiator (B) is contained in a small amount of 0.1 to 1.5 parts by mass with respect to 100 parts by mass of the group-containing resin (A), it is highly sensitive and laser Direct exposure is also possible. In addition, the photosensitive resin composition of the present invention is a composition that can be developed with a dilute aqueous alkali solution and has low warpage, but it adheres to various substrates similar to conventional solder resist compositions. It is possible to form a cured film pattern having excellent properties such as heat resistance, solder heat resistance, moisture resistance, chemical resistance, electroless gold plating resistance, and electrical insulation. Therefore, the photosensitive resin composition of the present invention can be advantageously applied to the formation of a cured film such as a solder resist or a resin insulating layer of a printed wiring board, particularly a flexible printed wiring board.

The present inventors have found that the warp during the post-heating step and component mounting is due to volatilization of the photopolymerizable initiator, and that the absorbance of the composition greatly affects the warp. As a result of further study of these phenomena, the present inventors have found that as a photopolymerization initiator to be blended together with a carboxyl group-containing resin (A) and a compound having two or more ethylenically unsaturated groups in the molecule (C), When the oxime ester-based photopolymerization initiator (B) having the group represented by the general formula (I) is used, the photosensitivity is sufficient even if added in a small amount and capable of laser direct exposure. The present inventors have found that a resin composition can be obtained and have completed the present invention.
Hereinafter, each component of the photosensitive resin composition of this invention is demonstrated.

  First, as the carboxyl group-containing resin (A), any of a carboxyl group-containing resin that itself does not have an ethylenically unsaturated double bond and a photosensitive carboxyl group-containing resin that has an ethylenically unsaturated double bond Although it is not limited to a specific thing, especially the compound (any of an oligomer and a polymer) as enumerated below can be used conveniently.

(1) Diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates; carboxyl group-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid; and polycarbonate polyols and polyethers Carboxyl group content obtained by polyaddition reaction of diol compounds such as polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups Urethane resin.
(2) Diisocyanate, bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, biphenol type epoxy resin A photosensitive carboxyl group-containing urethane resin obtained by polyaddition reaction of a bifunctional epoxy resin (meth) acrylate or a partially modified anhydride thereof, a carboxyl group-containing dialcohol compound, and a diol compound.
(3) During the synthesis of the resin of (1) or (2) , a compound having one hydroxyl group and one or more (meth) acryl groups in the molecule such as hydroxyalkyl (meth) acrylate is added, and the terminal ( (Meth) acrylic carboxyl group-containing urethane resin.
(4) During the synthesis of the resin of the above (1) or (2) , one isocyanate group and one or more (meth) acryl groups are introduced into the molecule such as an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate. The carboxyl group-containing urethane resin which added the compound which has and was terminally (meth) acrylated.
(5) A photosensitive carboxyl group-containing resin obtained by reacting (meth) acrylic acid with a polyfunctional (solid) epoxy resin as described later and adding a dibasic acid anhydride to the generated hydroxyl group.
(6) Obtained by reacting a polyfunctional epoxy resin obtained by epoxidizing the hydroxyl group of a bifunctional (solid) epoxy resin with epichlorohydrin with (meth) acrylic acid, and adding a dibasic acid anhydride to the produced hydroxyl group. A photosensitive carboxyl group-containing resin.
(7) A photosensitive carboxyl group-containing resin obtained by adding a compound having one epoxy group and one or more (meth) acryl groups in one molecule to the resins (1) to (6) .

Preferred among these carboxyl group-containing resins are those in which the compound (including diisocyanate) having an isocyanate group used in the synthesis of the resins of (1) to (4) is a diisocyanate having no benzene ring, and (5) In the case where the polyfunctional and bifunctional epoxy resins used for the synthesis of the resin of (6) are a compound having a linear structure having a bisphenol A skeleton, a bisphenol F skeleton, a biphenyl skeleton, a bixylenol skeleton, and a hydrogenated compound thereof Is preferable in terms of flexibility and the like. In another aspect, the resins (1) to (4) and the modified products thereof (7) have a urethane bond in the main chain, which is preferable for warpage. Moreover, since resin other than said (1) has a photosensitive group (radically polymerizable unsaturated double bond) in a molecule | numerator, it is preferable at the point of photocurability.
In the present specification, (meth) acrylate is a term that collectively refers to acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

Since the carboxyl group-containing resin (A) as described above has a large number of free carboxyl groups in the side chain of the backbone polymer, development with a dilute alkaline aqueous solution becomes possible.
The acid value of the carboxyl group-containing resin (A) is desirably in the range of 40 to 200 mgKOH / g, and more preferably in the range of 45 to 120 mgKOH / g. If the acid value of the carboxyl group-containing resin (A) is less than 40 mgKOH / g, alkali development becomes difficult. On the other hand, if it exceeds 200 mgKOH / g, dissolution of the exposed area by the developer proceeds, so the line becomes thinner than necessary. In some cases, the exposed portion and the unexposed portion are not distinguished from each other by dissolution and peeling with a developer, which makes it difficult to form a normal resist pattern.

  Moreover, although the weight average molecular weight of the said carboxyl group-containing resin (A) changes with resin frame | skeleton, generally the range of 2,000-150,000 is desirable, More preferably, it is the range of 5,000-100,000. is there. If the weight average molecular weight is less than 2,000, the tack-free performance of the coating film may be inferior, the moisture resistance of the coating film after exposure may be poor, the film may be reduced during development, and the resolution may be greatly inferior. On the other hand, when the weight average molecular weight exceeds 150,000, developability may be remarkably deteriorated, and storage stability may be inferior.

  The blending amount of such a carboxyl group-containing resin (A) is desirably in the range of 20 to 60% by mass of the total composition, and preferably in the range of 30 to 50% by mass. When the amount is less than the above range, the coating strength is lowered, which is not preferable. On the other hand, when the amount is larger than the above range, the viscosity of the composition is increased or the coating property is lowered, which is not preferable.

  Next, the oxime ester photopolymerization initiator (B) having the group represented by the general formula (I) used in the present invention has sufficient sensitivity even in a small amount, and the initiator volatilization at the time of post-heating and component mounting. It is effective in preventing warpage caused by. Usually, the photosensitive composition used for the photosensitive coverlay and the solder resist contains 5 to 20 parts by mass of a photopolymerization initiator with respect to 100 parts by mass of the carboxyl group-containing resin. However, the oxime ester photopolymerization initiator (B) having the group represented by the general formula (I) is sufficient in an amount of 0.1 to 1.5 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin (A). Furthermore, it gives a cured product with less warping after component mounting. In the case of a composition containing a large amount of photopolymerization initiator, it is probable that the photopolymerization initiator volatilizes during post-heating or reflow soldering for component mounting, and warpage occurs due to volume shrinkage. . From another aspect, this means that there is no problem even if a relatively large amount is added in the case of a photopolymerization initiator that is almost volatilized during thermosetting of the composition. That is, the manufacturing process of the flexible substrate is photocuring → thermosetting → postheating → component mounting (reflow soldering). To give a general example, the temperature history is photocuring (20-30 ° C. for several seconds). ) → thermosetting (140 to 160 ° C. for 30 to 60 minutes) → post heating (150 to 170 ° C. for 2 hours) → component mounting (240 to 260 ° C. for several seconds to several tens of seconds). Here, it is considered that the photopolymerization initiator, which is mostly volatilized during the thermal curing, has almost no volatile component remaining after the main curing and does not cause volume shrinkage during post-heating and component mounting. It is done. Examples of such a photopolymerization initiator include compounds that decrease by 50% or more upon heating at 150 ° C., and (B1a) described later is preferable.

The oxime ester photopolymerization initiator (B) having a group represented by the general formula (I) is preferably 2- (acetyloxyiminomethyl) thioxanthen-9-one represented by the following formula (V) And compounds represented by the following general formulas (VI) and (VII).

（式中、Ｒ^１０は、水素原子、ハロゲン原子、炭素数１〜１２のアルキル基、シクロペンチル基、シクロヘキシル基、フェニル基、ベンジル基、ベンゾイル基、炭素数２〜１２のアルカノイル基、炭素数２〜１２のアルコキシカルボニル基（アルコキシル基を構成するアルキル基の炭素数が２以上の場合、アルキル基は１個以上の水酸基で置換されていてもよく、アルキル鎖の中間に１個以上の酸素原子を有していてもよい）、又はフェノキシカルボニル基を表し、
Ｒ^１１、Ｒ^１３は、それぞれ独立に、フェニル基（炭素数１〜６のアルキル基、フェニル基もしくはハロゲン原子で置換されていてもよい）、炭素数１〜２０のアルキル基（１個以上の水酸基で置換されていてもよく、アルキル鎖の中間に１個以上の酸素原子を有していてもよい）、炭素数５〜８のシクロアルキル基、炭素数２〜２０のアルカノイル基又はベンゾイル基（炭素数が１〜６のアルキル基もしくはフェニル基で置換されていてもよい）を表し、
Ｒ^１２は、水素原子、フェニル基（炭素数１〜６のアルキル基、フェニル基もしくはハロゲン原子で置換されていてもよい）、炭素数１〜２０のアルキル基（１個以上の水酸基で置換されていてもよく、アルキル鎖の中間に１個以上の酸素原子を有していてもよい）、炭素数５〜８のシクロアルキル基、炭素数２〜２０のアルカノイル基又はベンゾイル基（炭素数が１〜６のアルキル基もしくはフェニル基で置換されていてもよい）を表す。）

(In the formula, R ¹⁰ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclopentyl group, a cyclohexyl group, a phenyl group, a benzyl group, a benzoyl group, an alkanoyl group having 2 to 12 carbon atoms, or 2 carbon atoms. To 12 alkoxycarbonyl groups (when the alkyl group constituting the alkoxyl group has 2 or more carbon atoms, the alkyl group may be substituted with one or more hydroxyl groups, and one or more oxygen atoms in the middle of the alkyl chain) Or a phenoxycarbonyl group,
R ¹¹ and R ¹³ are each independently a phenyl group (which may be substituted with a C 1-6 alkyl group, a phenyl group or a halogen atom), a C 1-20 alkyl group (one or more Which may be substituted with a hydroxyl group and may have one or more oxygen atoms in the middle of the alkyl chain), a cycloalkyl group having 5 to 8 carbon atoms, an alkanoyl group having 2 to 20 carbon atoms or a benzoyl group (Which may be substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group),
R ¹² is a hydrogen atom, a phenyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group or a halogen atom), or an alkyl group having 1 to 20 carbon atoms (substituted with one or more hydroxyl groups). And may have one or more oxygen atoms in the middle of the alkyl chain), a cycloalkyl group having 5 to 8 carbon atoms, an alkanoyl group having 2 to 20 carbon atoms or a benzoyl group (having a carbon number). 1-6 alkyl groups or phenyl groups optionally substituted). )

（式中、Ｒ^１４及びＲ^１５は、それぞれ独立に、炭素数１〜１２のアルキル基を表し、Ｍは、Ｓ、Ｏ又はＮＨを表し、Ｒ^１６、Ｒ^１７、Ｒ^１８、Ｒ^１９及びＲ^２０は、それぞれ独立に、水素原子又は炭素数１〜６のアルキル基を表し、ｍ及びｎは、０〜５の整数を表す。）

(In the formula, each of R ¹⁴ and R ¹⁵ independently represents an alkyl group having 1 to 12 carbon atoms, M represents S, O, or NH; R ¹⁶ , R ¹⁷ , R ¹⁸ , R ^19, and R; ²⁰ represents a hydrogen atom or a C1-C6 alkyl group each independently, and m and n represent the integer of 0-5.)

Among the oxime ester photopolymerization initiators (B), 2- (acetyloxyiminomethyl) thioxanthen-9-one represented by the formula (V) and a compound represented by the formula (VI) are more preferable. . Examples of commercially available products include CGI-325, Irgacure OXE01, and Irgacure OXE02 manufactured by Ciba Specialty Chemicals.
The oxime ester photopolymerization initiator as described above can be used alone or in combination of two or more.

  As described above, the optimum amount of the oxime ester photopolymerization initiator (B) is 0.1 to 1.5 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin (A). However, a photopolymerization initiator (B1) or photopolymerization assistant (B2) other than the oxime ester can be added in order to further ensure the photoreaction. For the purpose of reducing warpage due to post-heating, the amount of other initiator added is desirably 6 parts by mass or less in total with respect to 100 parts by mass of the carboxyl group-containing resin (A), more preferably. Is 5 parts by mass or less. Further, as an exception, the photopolymerization initiator (B1a) that volatilizes in the thermosetting step (heating at about 150 ° C.) is not affected by volatilization in the post-heating step even if it is added in a larger amount than the above range. It became clear that low warpage can be realized as expected. Such a heat-volatile photopolymerization initiator (B1a) can be selected by simple analysis by thermogravimetric analysis and headspace GC-MS, and is volatilized before and after thermosetting at 150 ° C. A compound in which the amount of the resulting photopolymerization initiator changes extremely (50% or more) is suitable. Specific examples include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1, and commercially available products include Irgacure 907 manufactured by Ciba Specialty Chemicals.

Other photopolymerization initiators that do not volatilize at 150 ° C. but can be added in small amounts include 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, N, N-dimethylaminoacetophenone and the like. Examples of commercially available products include Irgacure 369 and Irgacure 379 manufactured by Ciba Specialty Chemicals.
Further, as the acylphosphine oxide-based initiator, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2, Examples include 4,4-trimethyl-pentylphosphine oxide. Examples of commercially available products include Lucilin TPO manufactured by BASF and Irgacure 819 manufactured by Ciba Specialty Chemicals.

Other photoinitiators and sensitizers that can be used in the photosensitive resin composition of the present invention include benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, xanthone compounds, and tertiary compounds. An amine compound etc. can be mentioned.
Specific examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether.

Specific examples of the acetophenone compound include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, and 1,1-dichloroacetophenone.
Specific examples of the anthraquinone compound include 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, and 1-chloroanthraquinone.

Specific examples of the thioxanthone compound include 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone.
Specific examples of the ketal compound include acetophenone dimethyl ketal and benzyl dimethyl ketal.

  Specific examples of the benzophenone compound include, for example, benzophenone, 4-benzoyldiphenyl sulfide, 4-benzoyl-4′-methyldiphenyl sulfide, 4-benzoyl-4′-ethyldiphenyl sulfide, 4-benzoyl-4′-propyldiphenyl. Sulfide.

  Specific examples of the tertiary amine compound include, for example, an ethanolamine compound, a compound having a dialkylaminobenzene structure, such as 4,4′-dimethylaminobenzophenone (Nisso Cure MABP manufactured by Nippon Soda Co., Ltd.), 4,4′-diethylamino. Dialkylamino benzophenone such as benzophenone (EAB manufactured by Hodogaya Chemical Co.), and dialkylamino groups such as 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one (7- (diethylamino) -4-methylcoumarin) Containing coumarin compound, ethyl 4-dimethylaminobenzoate (Kayacure EPA manufactured by Nippon Kayaku Co., Ltd.), ethyl 2-dimethylaminobenzoate (Quantacure DMB manufactured by International Bio-Synthetics), 4-dimethylaminobenzoic acid ( -Butoxy) ethyl (Quantacure BEA, manufactured by International Bio-Synthetics), p-dimethylaminobenzoic acid isoamyl ethyl ester (Kayacure DMBI, manufactured by Nippon Kayaku Co., Ltd.), 2-ethylhexyl 4-dimethylaminobenzoate (manufactured by Van Dyk) Esolol 507), 4,4′-diethylaminobenzophenone (EAB manufactured by Hodogaya Chemical Co., Ltd.).

Among the photopolymerization initiators described above, thioxanthone compounds and tertiary amine compounds are preferred. The photosensitive resin composition of the present invention preferably contains a thioxanthone compound from the viewpoint of deep curable properties. Among them, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4 -Thioxanthone compounds such as diisopropylthioxanthone are preferred.
The amount of such a thioxanthone compound is preferably 2 parts by mass or less, more preferably 1 part by mass or less with respect to 100 parts by mass of the carboxyl group-containing resin (A). If the amount of the thioxanthone compound is too large, it is not preferable because it causes warping during post-heating and increases the cost of the product.

  As the tertiary amine compound, a compound having a dialkylaminobenzene structure is preferable, and among them, a dialkylaminobenzophenone compound and a dialkylamino group-containing coumarin compound having a maximum absorption wavelength of 350 to 410 nm are particularly preferable. As the dialkylaminobenzophenone compound, 4,4'-diethylaminobenzophenone is preferable because of its low toxicity. Dialkylamino group-containing coumarin compounds having a maximum absorption wavelength of 350 to 410 nm have a maximum absorption wavelength in the ultraviolet region, so that they are less colored and use a colored pigment as well as a colorless and transparent photosensitive resin composition. It is possible to provide a colored solder resist film reflecting the color of the above. In particular, 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one is preferable because it exhibits an excellent sensitizing effect on laser light having a wavelength of 400 to 410 nm.

  The amount of such a tertiary amine compound is preferably 0.1 to 2 parts by mass, more preferably 0.1 to 1 part by mass with respect to 100 parts by mass of the carboxyl group-containing resin (A). It is. When the amount of the tertiary amine compound is 0.1 parts by mass or less, there is a tendency that a sufficient sensitizing effect cannot be obtained. Exceeding 2 parts by mass is not preferable because it causes warping during post-heating and increases the cost of the product.

The photopolymerization initiator, photoinitiator aid and sensitizer as described above can be used alone or as a mixture of two or more.
The mixing ratio of these photopolymerization initiator and initiation assistant is such that the oxime ester photopolymerization initiator (B) having the group represented by the general formula (I) with respect to 100 parts by mass of the carboxyl group-containing resin (A). In addition to the prescription of the blending ratio of 0.1 to 1.5 parts by mass, the absorbance at 355 nm of the dried coating film of the composition including the colorant and sensitizer described later is 0.3 when the dry film thickness is 25 μm. It is preferable to add at a ratio so as to be in the range of -1.2. This range of absorbance was found to be effective in reducing warpage during post-heating and component mounting reflow soldering, which is the object of the present invention. Although details are not clear, it is considered that the photoreaction of the composition is within a range in which photocuring can be performed relatively uniformly in the surface layer and in the deep part. If the absorbance is higher than 1.2, light does not transmit to the deep part, a large amount of unreacted photocuring components remain, and there is a phenomenon in which the substrate is warped or swelled by abrupt reaction by post-heating or reflow soldering of component mounting. It was seen. On the other hand, if the absorbance is lower than 0.3, it is not suitable because light cannot be used effectively, and it cannot cope with high sensitivity and laser direct exposure which is one of the objects of the present invention. In addition, it has been clarified that the chemical resistance and the electroless gold plating property of the cured film are improved by adjusting the absorbance to the above-mentioned preferable range. These phenomena have not been clarified so far, and are the effects found for the first time by the present inventors.

  As the compound (C) having two or more ethylenically unsaturated groups in the molecule, various conventionally known (meth) acrylate monomers can be used and are not limited to specific ones. Specific examples include, for example, glycol diacrylates such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, tris-hydroxyethyl isocyanurate, and the like. Polyhydric acrylates such as polyhydric alcohols or their ethylene oxide adducts, propylene oxide adducts or caprolactone adducts; phenoxy acrylate, bisphenol A diacrylate, ethylene oxide adducts or propylene oxide adducts of these phenols, etc. Polyhydric acrylates of the above; urethane acrylates of the above polyalcohols; glycerin diglycidyl ether; Li serine triglycidyl ether, trimethylolpropane triglycidyl ether, polyvalent acrylates of glycidyl ethers such as triglycidyl isocyanurate; melamine acrylate; and the like each methacrylates corresponding to the acrylates.

  Furthermore, a polyfunctional epoxy resin such as a cresol novolac type epoxy resin, an epoxy acrylate resin obtained by reacting (meth) acrylic acid, and a hydroxy (meth) acrylate such as pentaerythritol triacrylate with a hydroxyl group of the epoxy acrylate resin Examples thereof include an epoxy urethane acrylate compound obtained by reacting a half urethane compound of diisocyanate such as isophorone diisocyanate. Such an epoxy acrylate resin can improve photocurability without deteriorating the touch drying property.

Among the above-mentioned ethylenically unsaturated group-containing compounds, those containing two ethylenically unsaturated groups are preferable, even if they are polyfunctional, modified by adding ethylene oxide, propylene oxide, caprolactone to the polyol. Of these, (meth) acrylates are preferred.
From the viewpoint of flame retardancy, a modified product by Michael addition reaction of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and a conventionally known polyfunctional (meth) acrylate is preferable. .

  The compounding amount of the compound (C) having two or more ethylenically unsaturated groups in the molecule as described above is more preferably 5 to 100 parts by mass, more preferably 100 parts by mass of the carboxyl group-containing resin (A). Is a ratio of 1 to 70 parts by mass. When the blending amount is less than 5 parts by mass, photocurability is lowered, and pattern formation becomes difficult by alkali development after irradiation with active energy rays, which is not preferable. On the other hand, when the amount exceeds 100 parts by mass, the solubility in an alkaline aqueous solution is lowered, and the coating film becomes brittle.

  A thermosetting component (D) can be added to the photosensitive resin composition of the present invention in order to impart heat resistance. A particularly preferred thermosetting component (D) is a thermosetting resin having two or more cyclic ether groups and / or cyclic thioether groups (hereinafter abbreviated as cyclic (thio) ether groups) in the molecule. Among these, bifunctional epoxy resins are preferable, and diisocyanate and its bifunctional blocked isocyanate can also be used.

  The thermosetting component (D) having two or more cyclic (thio) ether groups in such a molecule is either a three-, four- or five-membered cyclic ether group or a cyclic thioether group in the molecule. Or a compound having two or more two types of groups, for example, a compound having at least two epoxy groups in the molecule, that is, a polyfunctional epoxy compound (D-1), at least two oxetanyl in the molecule And a compound having a group, that is, a polyfunctional oxetane compound (D-2), a compound having two or more thioether groups in the molecule, that is, an episulfide resin (D-3).

  Examples of the polyfunctional epoxy compound (D-1) include JER828, JER834, JER1001, JER1004 manufactured by Japan Epoxy Resin, Epicron 840, Epicron 850, Epicron 1050, Epicron 1050, and Epitome 2055 manufactured by Dainippon Ink and Chemicals, Inc. Epototo YD-011, YD-013, YD-127, YD-128 manufactured by Kasei Co., Ltd., D.C. E. R. 317, D.E. E. R. 331, D.D. E. R. 661, D.D. E. R. 664, Ciba Specialty Chemicals' Araldide 6071, Araldide 6084, Araldide GY250, Araldide GY260, Sumitomo Chemical Industries Sumi-Epoxy ESA-011, ESA-014, ELA-115, ELA-128, Asahi Kasei Kogyo Co., Ltd. A. E. R. 330, A.I. E. R. 331, A.I. E. R. 661, A.I. E. R. Bisphenol A type epoxy resin such as 664 (all trade names); YL903 manufactured by Japan Epoxy Resin, Epicron 152, Epicron 165 manufactured by Dainippon Ink and Chemicals, Epototo YDB-400, YDB-500 manufactured by Tohto Kasei Co., Ltd. D. Chemicals manufactured by Dow Chemical Company. E. R. 542, Araldide 8011 manufactured by Ciba Specialty Chemicals, Sumi-epoxy ESB-400, ESB-700 manufactured by Sumitomo Chemical Co., Ltd., and A.D. E. R. 711, A.I. E. R. Brominated epoxy resins such as 714 (all trade names); JER152 and JER154 manufactured by Japan Epoxy Resin, and D.C. E. N. 431, D.D. E. N. 438, Epicron N-730, Epicron N-770, Epicron N-865, Etototo YDCN-701, YDCN-704 from Toto Kasei Co., Ltd., Araldide ECN1235 from Ciba Specialty Chemicals, Araldide ECN1273, Araldide ECN1299, Araldide XPY307, Nippon Kayaku Co., Ltd. EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, Sumitomo Chemical Industries Sumi-epoxy ESCN-195X, ESCN- 220, manufactured by Asahi Kasei Corporation. E. R. Novolak type epoxy resins such as ECN-235, ECN-299, etc. (both trade names); Epicron 830 manufactured by Dainippon Ink & Chemicals, JER807 manufactured by Japan Epoxy Resin, Epotot YDF-170 manufactured by Toto Kasei Co., YDF- 175, YDF-2001, YDF-2004, Araldide XPY306 manufactured by Ciba Specialty Chemicals, etc. (both trade names); Epototo ST-2004, ST-2007, ST- manufactured by Tohto Kasei Co., Ltd. Hydrogenated bisphenol A type epoxy resin such as 3000 (trade name); Japan Epoxy Resin JER604, Toto Kasei Epototo YH-434, Ciba Specialty Chemicals Araldide MY720, Sumitomo Chemical Co., Ltd. SUMI-EPOXY ELM Glycidylamine type epoxy resin such as 120 (all trade names); Hydantoin type epoxy resin such as Araldide CY-350 (trade name) manufactured by Ciba Specialty Chemicals; Celoxide 2021 manufactured by Daicel Chemical Industries, Ciba Specialty -Alicyclic epoxy resins such as Araldide CY175, CY179, etc. (both trade names) manufactured by Chemicals; YL-933 manufactured by Japan Epoxy Resin; E. N. , EPPN-501, EPPN-502, etc. (all trade names) trihydroxyphenylmethane type epoxy resin; Japan Epoxy Resin YL-6056, YX-4000, YL-6121 (all trade names), etc. Xylenol type or biphenol type epoxy resin or a mixture thereof; bisphenol S type such as EBPS-200 manufactured by Nippon Kayaku Co., Ltd., EPX-30 manufactured by Asahi Denka Kogyo Co., Ltd., EXA-1514 (trade name) manufactured by Dainippon Ink & Chemicals, Inc. Epoxy resin; Bisphenol A novolak type epoxy resin such as JER157S (trade name) manufactured by Japan Epoxy Resin; YL-931 manufactured by Japan Epoxy Resin, Araldide 163 manufactured by Ciba Specialty Chemicals, etc. (all trade names) Tetraphenylolethane type epoxy resin; Hexacyclic epoxy resins such as Araldide PT810 manufactured by Ba Specialty Chemicals Co., Ltd., TEPIC manufactured by Nissan Chemical Industries Co., Ltd. (both trade names); Diglycidyl phthalate resins such as Bremer DGT manufactured by NOF Corporation; ZX manufactured by Toto Kasei Co. Tetraglycidylxylenoylethane resin such as -1063; naphthalene group-containing epoxy resins such as Nippon Steel Chemical Co., Ltd. ESN-190, ESN-360, Dainippon Ink and Chemicals, Inc. HP-4032, EXA-4750, EXA-4700; Epoxy resins having a dicyclopentadiene skeleton such as HP-7200 and HP-7200H manufactured by Dainippon Ink &Chemicals; Glycidyl methacrylate copolymer epoxy resins such as CP-50S and CP-50M manufactured by Nippon Oil &Fats; and cyclohexylmaleimide And glycidyl methacrylate Copolymerized epoxy resin; epoxy-modified polybutadiene rubber derivatives (for example, PB-3600 manufactured by Daicel Chemical Industries), CTBN-modified epoxy resins (for example, YR-102, YR-450 manufactured by Tohto Kasei Co., Ltd.) and the like. However, it is not limited to these. These epoxy resins can be used alone or in combination of two or more. Among these, a novolac type epoxy resin, a heterocyclic epoxy resin, a bisphenol A type epoxy resin or a mixture thereof is particularly preferable.

  Examples of the polyfunctional oxetane compound (D-2) include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, 1,4-bis [(3-Methyl-3-oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3- In addition to polyfunctional oxetanes such as ethyl-3-oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and oligomers or copolymers thereof, oxetane Alcohol and novolak resin, poly (p-hydroxystyrene), cardo type Scan phenols, calixarenes, calix resorcin arenes, or the like ethers of a resin having a hydroxyl group such as silsesquioxane and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate is also included.

  Examples of the compound (D-3) having two or more cyclic thioether groups in the molecule include bisphenol A type episulfide resin YL7000 manufactured by Japan Epoxy Resins. An episulfide resin in which the oxygen atom of the epoxy group of the novolak type epoxy resin is replaced with a sulfur atom can also be used.

  The compounding amount of the thermosetting component (D) having two or more cyclic (thio) ether groups in the molecule is cyclic (thio) ether with respect to 1 equivalent of the carboxyl group of the carboxyl group-containing resin (A). The group is preferably in the range of 0.6 to 2.5 equivalents, more preferably 0.8 to 2.0 equivalents. When the blending amount of the thermosetting component (D) having two or more cyclic (thio) ether groups in the molecule is less than 0.6 equivalent, a carboxyl group remains in the cured film, resulting in heat resistance, alkali resistance, electricity This is not preferable because the insulating property is lowered. On the other hand, when the amount exceeds 2.5 equivalents, the low molecular weight cyclic (thio) ether group remains in the dry coating film, which is not preferable because the strength of the coating film decreases.

  When the thermosetting component (D) having two or more cyclic (thio) ether groups in the molecule is used, it is preferable to contain a thermosetting catalyst. Examples of such thermosetting catalysts include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole. Imidazole derivatives such as 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N -Amine compounds such as dimethylbenzylamine and 4-methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. Examples of commercially available products include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Kogyo Co., Ltd., U-CAT3503N manufactured by San Apro, U -CAT3502T (all are trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof), and the like. It is not particularly limited to these, as long as it is a thermosetting catalyst for an epoxy resin or an oxetane compound, or a catalyst that promotes the reaction between an epoxy group and / or an oxetanyl group and a carboxyl group, either alone or in combination of two or more. May be used. Guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine and isocyanuric acid adducts and 2,4-diamino-6-methacryloyloxyethyl-S-triazine and isocyanuric acid adducts can also be used. A compound that also functions in combination with the thermosetting catalyst.

  The blending amount of these thermosetting catalysts is sufficient in the usual quantitative ratio, for example, a carboxyl group-containing resin (A) or a thermosetting component (D) having two or more cyclic (thio) ether groups in the molecule. Preferably it is 0.1-20 mass parts with respect to 100 mass parts, More preferably, it is 0.5-15.0 mass parts.

  The photosensitive resin composition of this invention can mix | blend a coloring agent. As the colorant, conventionally known colorants such as red, blue, green and yellow can be used, and any of pigments, dyes and dyes may be used. However, it is preferable not to contain a halogen from the viewpoint of reducing the environmental burden and affecting the human body.

Blue colorant:
Blue colorants include phthalocyanine-based and anthraquinone-based compounds, and pigment-based compounds classified as Pigment, specifically, the following color index (CI; The Society of Dyers and Colorists) (Issued by The Society of Dyers and Colorists) can be listed with numbers: Pigment Blue 15, Pigment Blue 15: 1, Pigment Blue 15: 2, Pigment Blue 15: 3, Pigment Blue 15: 4 , Pigment Blue 15: 6, Pigment Blue 16, Pigment Blue 60.
The dye systems include Solvent Blue 35, Solvent Blue 63, Solvent Blue 68, Solvent Blue 70, Solvent Blue 83, Solvent Blue 87, Solvent Blue 94, Solvent Blue 97, Solvent Blue 122, Solvent Blue 136, Solvent Blue 67, Solvent Blue 70 etc. can be used. In addition to the above, a metal-substituted or unsubstituted phthalocyanine compound can also be used.

Green colorant:
Similarly, as the green colorant, there are phthalocyanine type and anthraquinone type, and specifically, Pigment Green 7, Pigment Green 36, Solvent Green 3, Solvent Green 5, Solvent Green 20, Solvent Green 28, etc. can be used. . In addition to the above, a metal-substituted or unsubstituted phthalocyanine compound can also be used.

Yellow colorant:
Examples of yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, anthraquinone, and the like.
Anthraquinone series: Solvent Yellow 163, Pigment Yellow 24, Pigment Yellow 108, Pigment Yellow 193, Pigment Yellow 147, Pigment Yellow 199, Pigment Yellow 202.
Isoindolinone type: Pigment Yellow 110, Pigment Yellow 109, Pigment Yellow 139, Pigment Yellow 179, Pigment Yellow 185.
Condensed azo series: Pigment Yellow 93, Pigment Yellow 94, Pigment Yellow 95, Pigment Yellow 128, Pigment Yellow 155, Pigment Yellow 166, Pigment Yellow 180.
Benzimidazolone series: Pigment Yellow 120, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 156, Pigment Yellow 175, Pigment Yellow 181.
Monoazo: Pigment Yellow 1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62, 62: 1, 65, 73, 74, 75, 97, 100, 104, 105, 111, 116 , 167, 168, 169, 182, 183.
Disazo: Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198.

Red colorant:
Examples of red colorants include monoazo, diazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone. It is done.
Monoazo: Pigment Red 1, 2, 3, 4, 5, 6, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 112, 114, 146, 147, 151 , 170, 184, 187, 188, 193, 210, 245, 253, 258, 266, 267, 268, 269.
Disazo: Pigment Red 37, 38, 41.
Monoazo lakes: Pigment Red 48: 1, 48: 2, 48: 3, 48: 4, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2, 53: 1, 53: 2, 57 : 1, 58: 4, 63: 1, 63: 2, 64: 1,68.
Benzimidazolone series: Pigment Red 171, Pigment Red 175, Pigment Red 176, Pigment Red 185, Pigment Red 208.
Perylene series: Solvent Red 135, Solvent Red 179, Pigment Red 123, Pigment Red 149, Pigment Red 166, Pigment Red 178, Pigment Red 179, Pigment Red 190, Pigment Red 194, Pigment Red 224.
Diketopyrrolopyrrole series: Pigment Red 254, Pigment Red 255, Pigment Red 264, Pigment Red 270, Pigment Red 272.
Condensed azo series: Pigment Red 220, Pigment Red 144, Pigment Red 166, Pigment Red 214, Pigment Red 220, Pigment Red 221 and Pigment Red 242.
Anthraquinone series: Pigment Red 168, Pigment Red 177, Pigment Red 216, Solvent Red 149, Solvent Red 150, Solvent Red 52, Solvent Red 207.
Kinacridone series: Pigment Red 122, Pigment Red 202, Pigment Red 206, Pigment Red 207, Pigment Red 209.

In addition, colorants such as purple, orange, brown, and black may be added for the purpose of adjusting the color tone.
Specifically, Pigment Violet 19, 23, 29, 32, 36, 38, 42, Solvent Violet 13, 36, CI Pigment Orange 1, CI Pigment Orange 5, CI Pigment Orange 13, CI Pigment Orange 14, CI CI Pigment Orange 16, CI Pigment Orange 17, CI Pigment Orange 24, CI Pigment Orange 34, CI Pigment Orange 36, CI Pigment Orange 38, CI Pigment Orange 40, CI Pigment Orange 43, CI Pigment Orange 46, CI Pigment Orange 49, CI CI Pigment Orange 51, CI Pigment Orange 61, CI Pigment Orange 63, CI Pigment Orange 64, CI Pigment Orange 71, CI Pigment Orange 73, CI Pigment Brown 23, CI Pigment Brown 25, CI Pigment Black 1, CI Pigment Black And the like.

  Although the specific blending ratio of the colorant is influenced by the type of the colorant used and the type of other additives, it cannot be said unconditionally, but in the photosensitive resin composition of the present invention, the absorbance at 355 nm is low. It is preferable to blend at a ratio of 0.3 to 1.2 at a dry film thickness of 25 μm. Particularly preferred colorants are blue and green phthalocyanine, anthraquinone, yellow anthraquinone, red diketopyrrolopyrrole, anthraquinone, and no halogen atoms. Among these, a red colorant and a yellow colorant are particularly preferable from the viewpoints of sensitivity and resolution.

  The photosensitive resin composition of the present invention can contain a filler as necessary in order to increase the physical strength of the coating film. As such a filler, at least one selected from the group consisting of known and commonly used inorganic fillers and organic fillers can be used, but inorganic fillers, particularly barium sulfate, spherical silica and talc are preferably used. Furthermore, NANOCRYL (trade name) XP 0396, XP made by Hanse-Chemie, in which nano silica is dispersed in the compound having one or more ethylenically unsaturated groups or the polyfunctional epoxy resin (E-1). 0596, XP 0733, XP 0746, XP 0765, XP 0768, XP 0953, XP 0954, XP 1045 (all are product grade names), NANOPOX (trade names) XP 0516, XP 0525, XP 0314 manufactured by Hanse-Chemie (Both product grade names) can also be used. These fillers can be blended alone or in combination of two or more.

  The blending amount of these fillers is preferably 300 parts by mass or less, more preferably 0.1 to 300 parts by mass, and particularly preferably 0.1 to 150 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin (A). Part. When the blending amount of the filler exceeds 300 parts by mass, the viscosity of the photosensitive resin composition is increased, the printability is lowered, and the cured product becomes brittle.

Furthermore, the photosensitive resin composition of the present invention uses an organic solvent for the synthesis of the carboxyl group-containing resin (A), the preparation of the composition, or the viscosity adjustment for application to a substrate or a carrier film. be able to.
Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, and the like. More specifically, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl Glycol ethers such as ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate , Esters such as propylene glycol butyl ether acetate; ethanol, propano , Ethylene glycol, alcohols such as propylene glycol; octane, aliphatic hydrocarbons decane; petroleum ether is petroleum naphtha, hydrogenated petroleum naphtha, and petroleum solvents such as solvent naphtha. Such organic solvents are used alone or as a mixture of two or more.

  If necessary, the photosensitive resin composition of the present invention may be a known conventional thermal polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol, phenothiazine, finely divided silica, organic bentonite, montmorillonite and the like. Conventional thickeners, antifoaming agents and / or leveling agents such as silicones, fluorines and polymers, silane coupling agents such as imidazoles, thiazoles and triazoles, antioxidants, rust inhibitors, etc. Such known and commonly used additives can be blended.

The photosensitive resin composition of this invention can also be made into the form of the dry film provided with the carrier film (support body) and the layer which consists of the said photosensitive resin composition formed on this carrier film.
In forming a dry film, the photosensitive resin composition of the present invention is diluted with the organic solvent to adjust to an appropriate viscosity, and a comma coater, a blade coater, a lip coater, a rod coater, a squeeze coater, a reverse coater, a transfer roll coater. A film can be obtained by applying a uniform thickness on a carrier film with a gravure coater, spray coater or the like, and drying usually at a temperature of 50 to 130 ° C. for 1 to 30 minutes. Although there is no restriction | limiting in particular about a coating film thickness, Generally, it is 10-150 micrometers by the film thickness after drying, Preferably it selects suitably in the range of 20-60 micrometers.

As the carrier film, a plastic film is used, and a plastic film such as a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, or a polystyrene film is preferably used. Although there is no restriction | limiting in particular about the thickness of a carrier film, Generally, it selects suitably in the range of 10-150 micrometers.
After the film is formed on the carrier film, it is desirable to further laminate a peelable cover film on the surface of the film for the purpose of preventing dust from adhering to the surface of the film.

  As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper or the like can be used, and when the cover film is peeled off, the adhesive strength between the film and the carrier film is exceeded. What is necessary is just to have a smaller adhesive force between the membrane and the cover film.

  The liquid photosensitive resin composition of the present invention having the above composition is adjusted to a viscosity suitable for the coating method with the organic solvent as necessary, and on the substrate, a dip coating method, a flow coating method, The coating is performed by a roll coating method, a bar coater method, a screen printing method, a curtain coating method, etc. A free coating film can be formed. Moreover, in the case of the said dry film form, it bonds together on a base material using a hot roll laminator etc. (It bonds together so that the said photosensitive resin composition layer and a base material may contact). In the case of a dry film having a peelable cover film on the photosensitive resin composition layer of the film, after the cover film is peeled off, the photosensitive resin composition layer and the substrate are hot so that they come into contact with each other. Bond using a roll laminator.

  Then, for the resulting coating film (photosensitive resin composition layer) (when the above dry film is used, after laminating on the substrate, do not peel off the carrier film), exposure (irradiation of active energy rays) Do. The exposure may be either a contact type (or non-contact type) method of selectively exposing with an active energy ray through a photomask on which a pattern has been formed, or a method of direct pattern exposure using a laser direct exposure machine. By this exposure, the exposed portion (portion irradiated with active energy rays) of the coating film is cured. Next, the unexposed portion is developed with a dilute alkaline aqueous solution (for example, 0.3 to 3% sodium carbonate aqueous solution) to form a resist pattern (if the dry film is used, the carrier film is peeled off after exposure and developed) ). After that, it is further heat-cured only, or heat-cured after irradiation with active energy rays or heat-cured after heat-curing, and finally cured (main-cured) by irradiation with active energy rays, thereby providing electrical insulation, adhesion, solder heat resistance, and chemical resistance. A cured film (cured product) excellent in electroless gold plating resistance and the like is formed. In the case of the photosensitive resin composition containing the thermosetting component (D), for example, by heating to a temperature of about 140 to 180 ° C. and thermosetting, the carboxyl group of the carboxyl group-containing resin (A) and molecules A thermosetting component (D) having two or more cyclic ether groups and / or cyclic thioether groups reacts, and has excellent properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical properties. A cured film can be formed.

  Examples of the substrate include a printed wiring board on which a circuit is formed in advance, in particular, a flexible printed wiring board, paper-phenol resin, paper-epoxy resin, glass cloth-epoxy resin, glass-polyimide, glass cloth / non-woven cloth-epoxy. Resin, glass cloth / paper-epoxy resin, synthetic fiber-epoxy resin, copper-clad laminates of all grades (FR-4 etc.) using polyimide, polyethylene, PPO, cyanate ester, etc., polyimide film PET film, glass substrate, ceramic substrate, wafer plate and the like can be used.

  Volatile drying performed after the photosensitive resin composition of the present invention is applied is a hot air circulation drying furnace, an IR furnace, a hot plate, a convection oven or the like (with a heat source of an air heating method using steam, It can be carried out using a method in which hot air is brought into countercurrent contact or a method in which a hot air is blown onto a support.

As an exposure machine used for the active energy ray irradiation, a high-pressure mercury lamp lamp, an ultra-high pressure mercury lamp lamp, a metal halide lamp, a mercury short arc lamp, and the like may be used as long as the apparatus irradiates ultraviolet rays in a range of 350 to 450 nm. Furthermore, a direct drawing apparatus (for example, a laser direct imaging apparatus that directly draws an image with a laser using CAD data from a computer) can also be used. As the laser light source of the direct drawing machine, either a gas laser or a solid laser may be used as long as laser light having a maximum wavelength in the range of 350 to 410 nm is used. The amount of exposure for image formation varies depending on the film thickness and the like, but is generally 20 to 800 mJ / cm ² , preferably 20 to 600 mJ / cm ² .

  The developing method can be a dipping method, a shower method, a spray method, a brush method or the like, and as a developer, potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, Alkaline aqueous solutions such as ammonia and amines can be used.

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following, “parts” and “%” are based on mass unless otherwise specified.

Synthesis example 1
(A-1) Synthesis of photosensitive carboxyl group-containing urethane resin corresponding to the carboxyl group-containing resin (3) described above and having a bisphenol A structure using alicyclic diisocyanate:
In a separable flask, as a bisphenol A type epoxy compound, 368.0 g of RE310S (bifunctional bisphenol A type epoxy resin, epoxy equivalent: 184 g / equivalent) manufactured by Nippon Kayaku Co., Ltd., acrylic acid (molecular weight: 72.06) 142.7 g, 2,6-di-tert-butyl-p-cresol as a thermal polymerization inhibitor, 2.94 g, and 1.53 g of triphenylphosphine as a reaction catalyst, were charged at a temperature of 98 ° C. It was made to react until an acid value became 0.5 mgKOH / g or less, and the epoxy carboxylate compound (a) (theoretical molecular weight: 510.7) was obtained. Next, 588.2 g of carbitol acetate and 105.5 g of dimethylolpropionic acid (b) (molecular weight: 134.16) were added to this reaction solution as a reaction solvent, and the temperature was raised to 45 ° C. To this solution, 264.7 g of isophorone diisocyanate (c) (molecular weight: 222.28) was gradually added dropwise so that the reaction temperature did not exceed 65 ° C. After completion of the dropwise addition, the temperature is raised to 80 ° C., and the reaction is performed for 6 hours until the absorption near 2250 cm ⁻¹ disappears by infrared absorption spectrum measurement, and the reaction is further performed for 2 hours at a temperature of 98 ° C. A resin solution containing 60 wt% was obtained. When the acid value was measured, it was 28.9 mgKOH / g (solid content acid value: 48.1 mgKOH / g). Hereinafter, this reaction product is referred to as a resin solution (A-1).

Synthesis example 2
(A-2) Synthesis of photosensitive carboxyl group-containing urethane resin corresponding to the carboxyl group-containing resin (3) and having a bisphenol F structure using alicyclic diisocyanate:
Bisphenol F-type epoxy resin (R110, manufactured by Mitsui Chemicals, Inc., epoxy equivalent of 169 g / equivalent) 169 parts (0.5 mol), acrylic acid 36 parts (0.5 mol), dimethylol butanoic acid 74 parts (0. 5 mol), 0.10 parts of methylhydroquinone and 185 parts of carbitol acetate were added and heated to 100 ° C. After confirming that the above mixture was uniformly dissolved, 3.0 parts of triethylamine was added and heated to 110 ° C. For about 25 hours. Thereafter, the reaction product was cooled to room temperature, charged with 152 parts (1.0 mol) of tetrahydrophthalic anhydride, heated to 100 ° C. and reacted for about 5 hours to obtain an acid anhydride-modified epoxy acrylate (d). Next, 832.5 parts (3.75 mol) of isophorone diisocyanate, 747 parts (0.75 mol) of polycarbonate polyol (PMHC-1050, manufactured by Kuraray Co., Ltd.), 222 of dimethylolbutanoic acid in a nitrogen stream atmosphere Parts (1.5 mol), 1662 parts of carbitol acetate and 6.5 parts of dibutyltin dilaurate were heated to 70 ° C. and reacted for about 8 hours. After stopping the nitrogen stream, the reaction mixture was cooled to room temperature, charged with 2463 parts (2.0 mol) of the acid anhydride-modified epoxy acrylate (d) in a dry air stream atmosphere, and heated to 80 ° C. For about 6 hours. Thereafter, the reaction product was cooled to room temperature, charged with 76 parts (0.5 mol) of tetrahydrophthalic anhydride, heated to 110 ° C. and reacted for about 4 hours, solid content acid value 93.5 mgKOH / g, solid content concentration A 60% photosensitive carboxyl group-containing urethane resin was obtained. Hereinafter, this reaction product is referred to as a resin solution (A-2).

Synthesis example 3
(A-3) Synthesis of photosensitive carboxyl group-containing urethane resin using alicyclic diisocyanate corresponding to the carboxyl group-containing resin (4) described above:
In a reaction vessel equipped with a stirrer, a thermometer, and a condenser, 2400 g (3 mol) of polycarbonate diol (number average molecular weight 800) derived from 1,5-pentanediol and 1,6-hexanediol, 603 g of dimethylolpropionic acid ( 4.5 mol) and 238 g (2.6 mol) of 2-hydroxyethyl acrylate as a monohydroxyl compound were added. Next, isophorone diisocyanate 1887 (8.5 mol) was added as polyisocyanate, and the mixture was heated to 60 ° C. with stirring and stopped. When the temperature in the reaction vessel started to decrease, the mixture was heated again and stirred at 80 ° C. The reaction was terminated after confirming that the absorption spectrum of the isocyanate group (2280 cm ⁻¹ ) disappeared in the infrared absorption spectrum. Carbitol acetate was added so that the solid content was 50% by mass. The acid value of the solid content of the obtained photosensitive carboxyl group-containing urethane resin was 50 mgKOH / g. Hereinafter, this reaction product is referred to as a resin solution (A-3).

(A-4) Photosensitive carboxyl group-containing resin corresponding to the carboxyl group-containing resin (6) described above and using a biphenyl novolac epoxy resin having a biphenyl skeleton:
A resin solution of Nippon Kayaku Co., Ltd. ZCR-1601H (acid value as solid content 65% resin is 98 mgKOH / g) is designated as A-4.

(A-5) Photosensitive carboxyl group-containing resin that corresponds to the carboxyl group-containing resin (7) described above and uses a polyfunctional epoxy resin having a bisphenol F structure:
A resin solution of Nippon Kayaku Co., Ltd. ZFR-1124 (acid value as solid content 63% resin is 102 mgKOH / g) is designated as A-5.

Examples 1 and 2, Reference Examples 1 to 5 and Comparative Examples 1 to 3
Using each of the resin solutions (A-1) to (A-5) above, blended in the proportions (parts by mass) shown in Table 1 together with various components shown in Table 1, and after premixing with a stirrer, 3 It knead | mixed with this roll mill and prepared the photosensitive resin composition for soldering resists. Here, when the dispersion degree of the obtained photosensitive resin composition was evaluated by particle size measurement using a grindometer manufactured by Eriksen Co., all compositions were 15 μm or less.

Performance evaluation:
<Optimal exposure / sensitivity>
The photosensitive resin compositions of the above Examples and Comparative Examples were pickled on a circuit pattern substrate having a copper thickness of 35 μm, washed with water, dried, and then applied to the entire surface by a screen printing method. It was dried for 60 minutes in a drying furnace. After drying, exposure is performed through a step tablet (Kodak No. 2) using a direct drawing device equipped with a semiconductor laser having a maximum wavelength of 355 nm, an exposure device equipped with a mercury short arc lamp, and a direct drawing machine equipped with a high-pressure mercury lamp, The optimum exposure dose was obtained when the pattern of the step tablet remaining when developing with a 1 wt% sodium carbonate aqueous solution at 30 ° C. for 60 seconds at a spray pressure of 0.2 MPa was 6 steps.

<Resolution>
A circuit pattern substrate having a line / space of 300/300 μm and a copper thickness of 35 μm was polished with buffalo, washed with water, dried, and then coated with the photosensitive resin composition of each of the above Examples and Comparative Examples by screen printing. It was dried for 30 minutes in a hot air circulation drying oven at 0 ° C. After drying, exposure was performed using a direct drawing apparatus equipped with a semiconductor laser having a maximum wavelength of 355 nm. As the exposure pattern, direct drawing data for drawing a 20/30/40/50/60/70/80/90/100 μm line in the space portion was used. The active energy ray was irradiated so that the exposure amount became the optimal exposure amount of the photosensitive resin composition. After the exposure, development was performed with a 1 wt% sodium carbonate aqueous solution at 30 ° C. to draw a pattern, and a cured coating film was obtained by heat curing at 150 ° C. for 60 minutes.
The minimum residual line of the cured coating film of the obtained photosensitive resin composition for solder resist was determined using an optical microscope adjusted to 200 times.

<Absorbance>
For the measurement of absorbance, an ultraviolet-visible spectrophotometer (Ubest-V-570DS manufactured by JASCO Corporation) and an integrating sphere device (ISN-470 manufactured by JASCO Corporation) were used. After applying the photosensitive resin composition of each of the above Examples and Comparative Examples to a glass plate using an applicator, the photosensitive resin composition was dried at 80 ° C. for 30 minutes using a hot air circulation drying oven, and the photosensitive resin composition was applied by dry coating. A film was prepared on a glass plate. Using an ultraviolet-visible spectrophotometer and an integrating sphere device, an absorbance baseline at 500 to 300 nm was measured on the same glass plate as that coated with the photosensitive resin composition. The absorbance of the produced glass plate with the dried coating film was measured, the absorbance of the dried coating film was calculated from the baseline, and the absorbance of the target light at a wavelength of 355 nm was obtained. In order to prevent deviation in absorbance due to deviation in coating film thickness, this operation is carried out by changing the coating thickness by the applicator into four stages, and a graph of the coating thickness and absorbance at 355 nm is created. The absorbance of the film was calculated and used as each absorbance.

Characteristic Test Evaluation Substrate Preparation Method: The photosensitive resin composition of each of the above Examples and Comparative Examples was applied on the entire surface of a polyimide substrate on which a copper circuit was formed by screen printing, dried at 80 ° C. for 20 minutes, and brought to room temperature. Allowed to cool. This substrate is exposed to a solder resist pattern with an optimum exposure amount using an exposure apparatus equipped with a mercury short arc lamp, and developed with a 1 wt% Na ₂ CO ₃ aqueous solution at 30 ° C. under a spray pressure of 0.2 MPa for 60 seconds. A resist pattern was obtained. This substrate was cured by heating at 150 ° C. for 60 minutes. The characteristic was evaluated as follows with respect to the obtained flexible wiring board (evaluation board | substrate).

<Color of coating film>
About the resist pattern of each said Example and each comparative example, the color of hardened | cured material was judged visually.

<Solder heat resistance>
The evaluation board | substrate which apply | coated the rosin-type flux was immersed in the solder tank previously set to 260 degreeC, and after washing | cleaning the flux with denatured alcohol, the swelling / peeling of the resist layer by visual observation was evaluated. The judgment criteria are as follows.
○: Dipping is not observed even after 10-second immersion and a peel test with a cellophane adhesive tape.
(Triangle | delta): It peels for a while when it immerses for 10 second and performs a peel test with a cellophane adhesive tape.
X: When immersed for 10 seconds, the resist layer swells and peels off.

<Electroless gold plating resistance>
The evaluation substrate is plated using commercially available electroless nickel plating bath and electroless gold plating bath under the conditions of nickel 0.5 μm and gold 0.03 μm. After evaluating the presence or absence of penetration, the presence or absence of peeling of the resist layer was evaluated by tape peeling. The judgment criteria are as follows.
○: Plating penetration and peeling of the resist layer are not observed.
Δ: Slight penetration was observed after plating, and peeling of the resist layer was also observed after tape peeling.
X: The resist layer is peeled off after plating.

<Corrosion resistance>
Using an IPC B-25 comb-type electrode B coupon instead of a copper foil substrate, an evaluation board was prepared under the above conditions, and a bias voltage of DC 100 V was applied to the comb-type electrode, and 85 ° C., 85% R.D. H. The presence or absence of migration after 1,000 hours was confirmed in a constant temperature and humidity chamber. The judgment criteria are as follows.
○: Almost no change △: Discolored ×: Migration has occurred

<Acid resistance>
The evaluation substrate was dipped in a 10 vol% H ₂ SO ₄ aqueous solution at room temperature for 30 minutes, soaking of the sulfuric acid aqueous solution and dissolution of the coating film were confirmed, and peeling of the resist layer by tape beer was confirmed. The judgment criteria are as follows.
○: Permeation of sulfuric acid aqueous solution, dissolution of the coating film, and no peeling of the resist layer.
Δ: Permeation of sulfuric acid aqueous solution, dissolution of coating film, or peeling of resist layer is slightly confirmed.
X: Permeation of sulfuric acid aqueous solution, dissolution of the coating film, or large peeling of the resist layer is confirmed.

<Warpage>
The entire surface of the photosensitive resin composition was applied by screen printing onto a 50 μm thick polyimide film (Kapton 300H), dried at 80 ° C. for 20 minutes, and allowed to cool to room temperature. This substrate is exposed to a solder resist pattern with an optimum exposure amount using an exposure apparatus equipped with a mercury short arc lamp, and developed with a 1 wt% Na ₂ CO ₃ aqueous solution at 30 ° C. under a spray pressure of 0.2 MPa for 60 seconds. A resist pattern was obtained. This substrate was cured by heating at 150 ° C. for 60 minutes. The obtained film was cut into 10 cm × 10 cm and the amount of warpage was measured.
Further, the amount of warpage of the film when the film was further heated at 170 ° C. for 2 hours in a hot air drying oven was also measured. (Warpage amount after post-heating)

The evaluation results are shown in Tables 2 and 3.

上記表２及び表３に示されるように、オキシムエステル系光重合開始剤を用いた本発明の実施例１、２、参考例１〜５においては、熱硬化後及び後加熱後の反りの発生を抑制できた。これに対し、オキシムエステル系以外の光重合開始剤を用いた比較例１〜３においては、熱硬化後及び後加熱後の反りの発生を抑制できず、特に、オキシムエステル系以外の揮発性のない光重合開始剤を用いた比較例２においては、吸光度が高く、後加熱後の反りの発生が著しかった。また、オキシムエステル系以外の光重合開始剤を比較的少量用いた比較例３においては、硬化不充分のためはんだ耐熱性に劣っていた。

As shown in Table 2 and Table 3 above, in Examples 1 and 2 and Reference Examples 1 to 5 of the present invention using an oxime ester photopolymerization initiator, occurrence of warpage after thermosetting and after heating. Was able to be suppressed. On the other hand, in Comparative Examples 1 to 3 using photopolymerization initiators other than oxime esters, it is not possible to suppress the occurrence of warping after thermosetting and after heating, and in particular, volatiles other than oxime esters are volatile. In Comparative Example 2 using no photopolymerization initiator, the absorbance was high, and the occurrence of warpage after post-heating was remarkable. Further, in Comparative Example 3 in which a relatively small amount of a photopolymerization initiator other than the oxime ester was used, the solder heat resistance was inferior due to insufficient curing.

Claims (11)

(A) bisphenol A, bisphenol F, biphenyl, have a bixylenol skeleton or structure is its water添骨price, and carboxyl group-containing resin having a urethane structure, a group represented by (B) the following general formula (I) An oxime ester-based photopolymerization initiator, and (C) a composition developable with a dilute alkaline aqueous solution containing a compound having two or more ethylenically unsaturated groups in the molecule, wherein the carboxyl group-containing resin ( A) The said oxime ester photoinitiator (B) is contained in the ratio of 0.1-1.5 mass part with respect to 100 mass parts, The photosensitive resin composition characterized by the above-mentioned.

(In the formula, R ¹ represents a hydrogen atom, a phenyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group, or a halogen atom), an alkyl group having 1 to 20 carbon atoms (one or more). Or may have one or more oxygen atoms in the middle of the alkyl chain), a cycloalkyl group having 5 to 8 carbon atoms, an alkanoyl group having 2 to 20 carbon atoms, or benzoyl. Represents a group (which may be substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group), and R ² is a phenyl group (substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group or a halogen atom). Or an alkyl group having 1 to 20 carbon atoms (which may be substituted with one or more hydroxyl groups, and may have one or more oxygen atoms in the middle of the alkyl chain), carbon number 5 ˜8 cycloalkyl groups, Represents an alkanoyl group or a benzoyl group prime 2-20 (carbon atoms may be substituted with 1-6 alkyl or phenyl group).) The photosensitive resin composition according to claim 1, wherein the carboxyl group-containing resin (A) is a resin having two or more radically polymerizable unsaturated double bonds. The photosensitive resin composition according to claim 1 or 2 , wherein the oxime ester photopolymerization initiator (B) is an oxime ester photopolymerization initiator represented by the following formula (V).

The photosensitive resin composition according to claim 1 or 2 , wherein the oxime ester photopolymerization initiator (B) is an oxime ester photopolymerization initiator represented by the following formula (VI).

(In the formula, R ¹⁰ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclopentyl group, a cyclohexyl group, a phenyl group, a benzyl group, a benzoyl group, an alkanoyl group having 2 to 12 carbon atoms, or 2 carbon atoms. To 12 alkoxycarbonyl groups (when the alkyl group constituting the alkoxyl group has 2 or more carbon atoms, the alkyl group may be substituted with one or more hydroxyl groups, and one or more oxygen atoms in the middle of the alkyl chain) Or a phenoxycarbonyl group,
R ¹¹ and R ¹³ are each independently a phenyl group (which may be substituted with a C 1-6 alkyl group, a phenyl group or a halogen atom), a C 1-20 alkyl group (one or more Which may be substituted with a hydroxyl group and may have one or more oxygen atoms in the middle of the alkyl chain), a cycloalkyl group having 5 to 8 carbon atoms, an alkanoyl group having 2 to 20 carbon atoms or a benzoyl group (Which may be substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group),
R ¹² is a hydrogen atom, a phenyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group or a halogen atom), or an alkyl group having 1 to 20 carbon atoms (substituted with one or more hydroxyl groups). And may have one or more oxygen atoms in the middle of the alkyl chain), a cycloalkyl group having 5 to 8 carbon atoms, an alkanoyl group having 2 to 20 carbon atoms or a benzoyl group (having a carbon number). 1-6 alkyl groups or phenyl groups optionally substituted). ) As a photopolymerization initiator, in addition to the oxime ester-based photopolymerization initiator (B), any of claims 1 to 4, characterized in that it comprises a photoinitiator 50% is volatilized at 0.99 ° C. (B1a) A photosensitive resin composition according to claim 1. Furthermore, a thermosetting component (D) is contained, The photosensitive resin composition as described in any one of Claims 1 thru | or 5 characterized by the above-mentioned. The photosensitive resin composition according to any one of claims 1 to 6 , wherein the dry coating film has an absorbance at 355 nm in a range of 0.3 to 1.2 at a dry film thickness of 25 µm. The photosensitive dry film obtained by apply | coating and drying the photosensitive resin composition as described in any one of the said Claims 1 thru | or 7 on a carrier film. Hardened | cured material obtained by photocuring the photosensitive resin composition as described in any one of the said Claims 1 thru | or 7 , or the dry film of the said Claim 9 on copper. A cured product obtained by photocuring the photosensitive resin composition according to any one of claims 1 to 7 or the dry film according to claim 9 with a laser oscillation light source. The photosensitive resin composition according to any one of claims 1 to 7 or the dry film according to claim 9 is photocured with a laser beam having a maximum wavelength of 350 to 410 nm, and then thermoset. A printed wiring board having a cured film obtained as described above.