WO2018179260A1 - Photosensitive resin composition, pattern cured film, method for manufacturing pattern cured film, photosensitive element, printed wiring board, and method for manufacturing printed wiring board - Google Patents

Abstract

Provided is a photosensitive resin composition which exhibits excellent adhesion to a substrate even under extreme curing conditions, and can improve warpage even when used for forming a permanent mask resist of a thin printed wiring board. The photosensitive resin composition contains an acid modified vinyl group-containing epoxy resin (A), a photopolymerizable monomer (B) having an ethylenically unsaturated bond, a photopolymerization initiator (C), an inorganic filler (D), and a melamine compound-containing curing agent (E), wherein the content of the inorganic filler (D) is 30-60 mass% of the total solid content in the photosensitive resin composition, and the content of the curing agent (E) is 75-140 parts by mass per 100 parts by mass of the acid modified vinyl group-containing epoxy resin (A).

Description

Photosensitive resin composition, patterned cured film and method for producing the same, photosensitive element, printed wiring board, and method for producing printed wiring board

The present invention relates to an alkali-developable photosensitive resin composition for a protective film of a printed wiring board, and more specifically, for a protective film of a printed wiring board used as a permanent mask resist in the resist field such as a substrate for a semiconductor package. The present invention relates to a photosensitive resin composition.

In the field of printed wiring boards, conventionally, a permanent mask resist (protective film) is formed on a printed wiring board. As a method for forming a pattern of a photosensitive resist, a colored photosensitive resin composition is applied to a substrate, dried, and then cured by selectively irradiating with ultraviolet rays, and then only an uncured portion is developed with an alkaline solution or the like. A photolithography method in which pattern formation is performed by removing the mainstream. This permanent mask resist has a role of preventing the solder from adhering to unnecessary portions of the conductor layer of the printed wiring board in the process of flip chip mounting the semiconductor element on the printed wiring board via solder. Further, the permanent mask resist has a role of preventing corrosion of the conductor layer and maintaining electrical insulation between the conductor layers when the printed wiring board is used.

Conventionally, permanent mask resists in the production of printed wiring boards have been produced by methods such as screen printing or roll coating with thermosetting or photosensitive resin compositions.

For example, in a flexible wiring board using mounting methods such as FC, TAB, and COF, a thermosetting resin paste is screen printed except for a rigid wiring board, an IC chip, an electronic component, or an LCD panel and a connection wiring pattern portion, A permanent mask resist is formed by thermosetting (see, for example, Patent Document 1).

Further, in recent years, with the thinning of the printed wiring board, there is a problem that when the permanent mask resist is formed, the printed wiring board is likely to warp due to thermal contraction. Therefore, we tried to improve the warpage by increasing the rigidity by tightening the curing conditions of the permanent mask resist. However, when the curing conditions are strict, there is a problem that peeling occurs between the permanent mask resist and the substrate.

JP 2003-198105 A

In the present invention, even when used for forming a permanent mask resist of a thin printed wiring board, the warpage can be improved, and even if the curing conditions are strict to achieve high rigidity, the gap between the permanent mask resist and the substrate can be improved. Photosensitive resin composition capable of preventing peeling, patterned cured film and method for producing the same, photosensitive element, printed wiring board comprising permanent mask resist formed using these, and method for producing printed wiring board The purpose is to provide.

In order to achieve the above object, the inventors have studied high-stiffness solder resist characteristics and composition, and as a result, in a photosensitive resin composition using an acid-modified vinyl group-containing epoxy resin, a resin having a high elastic modulus. By applying the composition, and containing a specific amount of 30-60 mass% inorganic filler and a curing agent, warpage of the printed wiring board due to thermal shrinkage during the formation of the permanent mask resist, and between the permanent mask resist and the substrate It has been found that both peeling can be reduced, and the present invention has been completed. That is, this invention provides the following photosensitive resin composition, the pattern cured film using the same, its manufacturing method, a photosensitive element, a printed wiring board, and the manufacturing method of a printed wiring board.

[1] Contains (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerizable monomer having an ethylenically unsaturated bond, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a curing agent. A photosensitive resin composition comprising: (D) the content of the inorganic filler is 30 to 60% by mass of the total solid content in the photosensitive resin composition; and (E) the content of the curing agent is (A) A photosensitive resin composition having 75 to 140 parts by mass per 100 parts by mass of the acid-modified vinyl group-containing epoxy resin.

[2] The acid-modified vinyl group-containing epoxy resin synthesized using a novolac type epoxy resin in which the (A) acid-modified vinyl group-containing epoxy resin has a structural unit represented by the following general formula (1): Acid-modified vinyl group-containing epoxy resin synthesized using a bisphenol novolac type epoxy resin having a structural unit represented by the formula (2) and a bisphenol novolak type epoxy resin having a structural unit represented by the following general formula (3) The photosensitive resin composition according to [1], which contains at least one selected from the group consisting of acid-modified vinyl group-containing epoxy resins synthesized using

[In the general formula (1), R ¹¹ represents a hydrogen atom or a methyl group, Y ¹ represents a hydrogen atom or a glycidyl group, and the novolac epoxy resin having a structural unit represented by the general formula (1) The molar ratio of hydrogen atom to glycidyl group (hydrogen atom / glycidyl group) is 0/100 to 30/70. ]

[In General Formula (2), two R ^{12 s} each independently represent a hydrogen atom or a methyl group; two Y ^{2 s} each independently represent a hydrogen atom or a glycidyl group; and two R ^{12 s} are the same or different. Provided that at least one of Y ² represents a glycidyl group. ]

[In the general formula (3), two R ^{13 s} each independently represent a hydrogen atom or a methyl group, two Y ^{3 s} each independently represent a hydrogen atom or a glycidyl group, and the two R ^{13 s} are the same or different. Provided that at least one of Y ³ represents a glycidyl group. ]

[3] The (A) acid-modified vinyl group-containing epoxy resin has a novolak epoxy resin having a structural unit represented by the general formula (1), and a bisphenol having a structural unit represented by the general formula (2). At least one epoxy resin (a) selected from the group consisting of a novolak-type epoxy resin and a bisphenol novolac-type epoxy resin having a structural unit represented by the general formula (3), and a vinyl group-containing monocarboxylic acid (b The photosensitive resin composition according to [2], which is a resin obtained by reacting a saturated or unsaturated group-containing polybasic acid anhydride (c) with a resin (A ′) obtained by reacting with a resin (A ′).

[4] (E) The curing agent contains a compound that cures by reacting with a carboxyl group and a hydroxyl group, and a compound that reacts and cures with a carboxyl group, a hydroxyl group, and a glycidyl group [1] to [3] ] The photosensitive resin composition of any one of.

[5] (E) The curing agent contains an epoxy resin and a melamine compound, and the content of the epoxy resin in (E) the curing agent is 15 per 100 parts by mass of the (A) acid-modified vinyl group-containing epoxy resin. The photosensitive resin according to [4], in which the content of the melamine compound in the (E) curing agent is 15 to 100 parts by mass per 100 parts by mass of the (A) acid-modified vinyl group-containing epoxy resin. Composition.

[6] Any of [1] to [5], wherein (B) the photopolymerizable monomer having an ethylenically unsaturated bond is a polyfunctional photopolymerizable monomer having three or more ethylenically unsaturated bonds in one molecule. 2. The photosensitive resin composition according to item 1.

[7] The photosensitive resin composition according to any one of [1] to [6], further comprising (F) a pigment.

[8] The photosensitive resin composition according to any one of [1] to [7], further comprising (G) an elastomer.

[9] A pattern cured film formed from the photosensitive resin composition according to any one of [1] to [8].

[10] A step of applying and drying the photosensitive resin composition according to any one of [1] to [8] on a substrate to form a coating film, and irradiating the coating film with active light to form a pattern A method for producing a cured pattern film, comprising: a step of exposing to light, a step of removing an unexposed portion by development to obtain a pattern resin film, and a step of curing the pattern resin film.

[11] A photosensitive element having a support and a photosensitive layer using the photosensitive resin composition according to any one of [1] to [8] on the support.

[12] A printed wiring board comprising a permanent mask resist formed from the photosensitive resin composition according to any one of [1] to [8].

[13] A step of forming a photosensitive layer on the substrate using the photosensitive resin composition according to any one of [1] to [8] or the photosensitive element according to [11], The manufacturing method of a printed wiring board which has the process of forming a resist pattern using a layer, and the process of hardening | curing this resist pattern and forming a permanent mask resist in order.

According to the present invention, even when used for forming a permanent mask resist on a thin printed wiring board, the warpage can be improved, and the permanent mask resist and the substrate can be used even if the curing conditions are strict to achieve high rigidity. Of a photosensitive resin composition capable of preventing peeling between the two, a pattern cured film and a method for producing the same, a photosensitive element, and a printed wiring board and a printed wiring board having a permanent mask resist formed using the photosensitive element A manufacturing method can be provided.

Hereinafter, preferred embodiments of the present invention will be described in detail.
[Photosensitive resin composition]
First, the photosensitive resin composition which concerns on suitable embodiment of this invention is demonstrated.
The photosensitive resin composition of the present invention comprises (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerizable monomer having an ethylenically unsaturated bond, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) It contains a curing agent (hereinafter simply referred to as (A) component, (B) component, (C) component, (D) component, (E) component, etc.)).

<(A) Acid-modified vinyl group-containing epoxy resin>
The (A) acid-modified vinyl group-containing epoxy resin used in the present invention will be described.
(A) The acid-modified vinyl group-containing epoxy resin is obtained by modifying an epoxy resin with a vinyl group-containing organic acid. For example, it is saturated with a resin obtained by reacting an epoxy resin with a vinyl group-containing monocarboxylic acid. An epoxy resin obtained by reacting a group or unsaturated group-containing polybasic acid anhydride can be used.

The (A) acid-modified vinyl group-containing epoxy resin used in the present invention is a structural unit represented by the following general formula (1) from the viewpoint of being capable of alkali development and being excellent in resolution and adhesiveness. A novolak-type epoxy resin (for example, a novolak-type epoxy resin represented by the following general formula (1 ′)), a bisphenol novolac-type epoxy resin having a structural unit represented by the following general formula (2), and the following general formula Obtained by reacting at least one epoxy resin (a) selected from the group consisting of bisphenol novolac type epoxy resins having the structural unit represented by (3) with a vinyl group-containing monocarboxylic acid (b). A resin (A ″) obtained by reacting the resin (A ′) with a saturated or unsaturated group-containing polybasic acid anhydride (c) is preferable.

(Epoxy resin (a))

[In the general formulas (1) and (1 ′), R ¹¹ represents a hydrogen atom or a methyl group, Y ¹ represents a hydrogen atom or a glycidyl group, and has a structural unit represented by the general formula (1) In the epoxy resin, the molar ratio of hydrogen atom to glycidyl group (hydrogen atom / glycidyl group) is 0/100 to 30/70. In the general formula (1 ′), n1 represents a number of 1 or more, and a plurality of R ¹¹ and Y ¹ may be the same or different. However, at least one Y ¹ represents a glycidyl group. ]

In the epoxy resin having the structural unit represented by the general formula (1) and in the epoxy resin represented by the general formula (1 ′), the molar ratio of Y ¹ as a hydrogen atom to Y ¹ as a glycidyl group (Hydrogen atom / glycidyl group) is 0/100 to 30/70, preferably 0/100 to 10/90.

The number of structural units of the structural unit in one molecule of the epoxy resin (a) having the structural unit represented by the general formula (1) and the number of structural units represented by n1 in the general formula (1 ′) are 1 The number is preferably 10 to 200, more preferably 30 to 150, still more preferably 30 to 100.
Here, the number of structural units represents an integer value when the epoxy resin (a) is composed of a single kind of molecule, and a rational number that is an average value when the epoxy resin (a) is an aggregate of a plurality of kinds of molecules. . Hereinafter, the same applies to the number of structural units.

[In General Formula (2), two R ^{12 s} each independently represent a hydrogen atom or a methyl group, and two Y ^{2 s} each independently represent a hydrogen atom or a glycidyl group. Two R ¹² may be the same or different, and two Y ² may be the same or different. However, at least one of Y ² represents a glycidyl group. ]

The number of structural units of the structural unit in one molecule of the epoxy resin (a) having the structural unit represented by the general formula (2) is one or more, and adhesion to the copper substrate, heat resistance, and electricity From the viewpoint of improving the insulation, it is preferably 10 to 100, more preferably 15 to 80, and still more preferably 15 to 70.

[In General Formula (3), two R ^{13 s} each independently represent a hydrogen atom or a methyl group, and two Y ^{3 s} each independently represent a hydrogen atom or a glycidyl group. Two R ¹³ may be the same or different, and two Y ³ may be the same or different. However, at least one of Y ³ represents a glycidyl group. ]

The number of structural units of the structural unit in one molecule of the epoxy resin (a) having the structural unit represented by the general formula (3) is one or more, and adhesion to a copper substrate, heat resistance and electricity From the viewpoint of improving the insulation, it is preferably 10 to 100, more preferably 15 to 80, and still more preferably 15 to 70.

Examples of the novolac type epoxy resin having the structural unit represented by the general formula (1) include a phenol novolac type epoxy resin and a cresol novolak type epoxy resin. These novolak-type epoxy resins can be obtained, for example, by reacting a phenol novolak resin, a cresol novolak resin and epichlorohydrin by a known method.

As the epoxy resin (a), from the viewpoint of having excellent process tolerance and improving solvent resistance, a novolak epoxy resin having a structural unit represented by the general formula (1), for example, the general formula (1) A novolac type epoxy resin represented by ′) is preferred.

Examples of the phenol novolak type epoxy resin or cresol novolak type epoxy resin represented by the general formula (1 ′) include YDCN-701, YDCN-702, YDCN-703, YDCN-704, YDCN-704L, YDPN-638, and YDPN. -602 (above, manufactured by Toto Kasei Co., Ltd., trade name), DEN-431, DEN-439 (above, made by Dow Chemical Co., Ltd., trade name), EOCN-120, EOCN-102S, EOCN-103S, EOCN-104S, EOCN-1012, EOCN-1025, EOCN-1027, BREN (above, Nippon Kayaku Co., Ltd., trade name), EPN-1138, EPN-1235, EPN-1299 (above, made by Ciba Specialty Chemicals, Product name), N-730, N-770 N-865, N-870, N-665, N-673, VH-4150, VH-4240 (manufactured by DIC Corporation, trade name) is commercially available.

In order to promote the reaction between the hydroxyl group and epichlorohydrin, the reaction is preferably carried out in a polar organic solvent such as dimethylformamide, dimethylacetamide or dimethylsulfoxide in the presence of an alkali metal hydroxide at a reaction temperature of 50 to 120 ° C. When the reaction temperature is less than 50 ° C., the reaction is slow, and when the reaction temperature is 120 ° C., many side reactions tend to occur.

In addition, the epoxy resin (a) is represented by the general formula (2) and / or the general formula (3) from the viewpoint of further reducing the warpage of the thin film substrate and further improving the thermal shock resistance. It is preferable to use a bisphenol novolac type epoxy resin having a structural unit of

In the above general formula (3), R ¹³ is a hydrogen atom and Y ³ is a glycidyl group as EXA-7376 series (trade name, manufactured by DIC Corporation), and R ¹³ is a methyl group. Y ³ having a glycidyl group is commercially available as EPON SU8 series (trade name, manufactured by Japan Epoxy Resin Co., Ltd.).

(Vinyl group-containing monocarboxylic acid (b))
Examples of the vinyl group-containing monocarboxylic acid (b) include acrylic acid, a dimer of acrylic acid, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, α- Acrylic acid derivatives such as cyanocinnamic acid, half-ester compounds which are reaction products of hydroxyl group-containing acrylates and dibasic acid anhydrides, vinyl group-containing monoglycidyl ethers or vinyl group-containing monoglycidyl esters and dibasic acid anhydrides The half-ester compound which is a reaction product of is mentioned. The vinyl group-containing monocarboxylic acid (b) can be used alone or in combination of two or more.

The half ester compound is obtained by reacting a hydroxyl group-containing acrylate, a vinyl group-containing monoglycidyl ether or a vinyl group-containing monoglycidyl ester with a dibasic acid anhydride in an equimolar ratio. These vinyl group-containing monocarboxylic acids (b) can be used singly or in combination of two or more.

Examples of the hydroxyl group-containing acrylate, vinyl group-containing monoglycidyl ether, and vinyl group-containing monoglycidyl ester used in the synthesis of the half ester compound as an example of the vinyl group-containing monocarboxylic acid (b) include hydroxyethyl acrylate, hydroxyethyl Methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol triacrylate, pentaerythritol tris Methacrylate, dipentaerythritol pentaacrylate, Pentaerythritol penta methacrylate, glycidyl acrylate, glycidyl methacrylate.

As the dibasic acid anhydride used for the synthesis of the half ester compound, one containing a saturated group or one containing an unsaturated group can be used. Specific examples of dibasic acid anhydrides include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride. Examples include acid, ethylhexahydrophthalic anhydride, itaconic anhydride and the like.

In the reaction of the above epoxy resin (a) with the vinyl group-containing monocarboxylic acid (b), the vinyl group-containing monocarboxylic acid (b) is preferably 0.8 relative to 1 equivalent of the epoxy group of the epoxy resin (a). The reaction is preferably performed at a ratio of 5 to 1.05 equivalents, more preferably 0.6 to 1.05 equivalents, and more preferably at a ratio of 0.8 to 1.0 equivalents.

The epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b) can be reacted by dissolving in an organic solvent. Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, Glycol ethers such as dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether and triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate, aliphatic carbonization such as octane and decane Examples thereof include petroleum solvents such as hydrogen, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

Furthermore, it is preferable to use a catalyst in order to promote the reaction. As the catalyst, for example, triethylamine, benzylmethylamine, methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylmethylammonium iodide, triphenylphosphine, and the like can be used. The amount of the catalyst used is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass in total of the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b).

It is also preferable to use a polymerization inhibitor for the purpose of preventing polymerization during the reaction. Examples of the polymerization inhibitor include hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol and the like. The amount of the polymerization inhibitor used is preferably 0.01 to 1 part by mass with respect to 100 parts by mass in total of the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b). The reaction temperature is preferably 60 to 150 ° C, more preferably 80 to 120 ° C.

If necessary, a vinyl group-containing monocarboxylic acid (b) and a phenolic compound such as p-hydroxyphenethyl alcohol, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, biphenyltetracarboxylic acid A polybasic acid anhydride such as an anhydride can be used in combination.

Thus, the resin (A ′) obtained by reacting the epoxy resin (a) with the vinyl group-containing monocarboxylic acid (b) is a glycidyl group of the epoxy resin (a) and the vinyl group-containing monocarboxylic acid (b). It is presumed to have a hydroxyl group formed by an addition reaction with a carboxyl group.

(A) The above-mentioned resin (A ″), which is an embodiment of an acid-modified vinyl group-containing epoxy resin, is further added to the resin (A ′) obtained above, in addition to a saturated or unsaturated group-containing polybasic acid anhydride (c). (Hereinafter sometimes simply referred to as polybasic acid anhydride (c)). In the resin (A ″) thus obtained, the hydroxyl group of the resin (A ′) is synthesized. When it is an acid-modified vinyl group-containing epoxy resin in which the acid anhydride group of the polybasic acid anhydride (c) is half-esterified (including the hydroxyl group originally present in the epoxy resin (a)) Inferred.

(Polybasic acid anhydride (c))
As the polybasic acid anhydride (c), one containing a saturated group or one containing an unsaturated group can be used. Specific examples of the polybasic acid anhydride (c) include, for example, succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, Examples include methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride. A polybasic acid anhydride (c) can be used individually by 1 type or in combination of 2 or more types.

In the reaction of the resin (A ′) with the polybasic acid anhydride (c), the polybasic acid anhydride (c) is 0.1 to 1.0 equivalent per 1 equivalent of the hydroxyl group in the resin (A ′). By reacting, the acid value of the acid-modified vinyl group-containing epoxy resin can be adjusted.

(A) The acid value of the acid-modified vinyl group-containing epoxy resin is preferably 30 to 150 mgKOH / g, more preferably 40 to 120 mgKOH / g, and particularly preferably 50 to 100 mgKOH / g. If the acid value is less than 30 mg KOH / g, the solubility of the photosensitive resin composition in a dilute alkaline solution tends to be reduced, and if it exceeds 150 mg KOH / g, the electric properties of the cured film tend to be reduced.

The reaction temperature between the resin (A ′) and the polybasic acid anhydride (c) is preferably 60 to 120 ° C.

Further, as necessary, as the epoxy resin (a), for example, a hydrogenated bisphenol A type epoxy resin can be partially used together. Further, (A) acid-modified vinyl group-containing epoxy resin, styrene-maleic acid series such as hydroxyethyl acrylate modified product of styrene-maleic anhydride copolymer or hydroxyethyl acrylate modified product of styrene-maleic anhydride copolymer A part of the resin may be used in combination.

In the present specification, (meth) acrylic acid means acrylic acid and methacrylic acid corresponding thereto, (meth) acrylate means acrylate and corresponding methacrylate, and (meth) acryloyl group means acryloyl. Group and its corresponding methacryloyl group, and (meth) acryloxy group means an acryloxy group and its corresponding methacryloxy group.

((A) Molecular weight of acid-modified vinyl group-containing epoxy resin)
The weight average molecular weight of the component (A) acid-modified vinyl group-containing epoxy resin is preferably 3,000 to 30,000, more preferably 4 from the viewpoint of improving adhesion to a copper substrate, heat resistance and electrical insulation. 5,000 to 25,000, more preferably 5,000 to 18,000. Here, the weight average molecular weight is a polyethylene-converted weight average molecular weight measured by a gel permeation chromatography (GPC) method using tetrahydrofuran as a solvent. More specifically, for example, a value measured by the following GPC measurement apparatus and measurement conditions and converted using a standard polystyrene calibration curve can be used as the weight average molecular weight. The calibration curve is prepared by using five sample sets (“PStQuick MP-H” and “PStQuick B”, manufactured by Tosoh Corporation) as standard polystyrene.
(GPC measuring device)
GPC apparatus: High-speed GPC apparatus “HCL-8320GPC”, detector is a differential refractometer or UV, manufactured by Tosoh Corporation Column: column TSKgel SuperMultipore HZ-H (column length: 15 cm, column inner diameter: 4.6 mm), Tosoh Corporation Made by company (measurement conditions)
Solvent: Tetrahydrofuran (THF)
Measurement temperature: 40 ° C
Flow rate: 0.35 ml / min Sample concentration: 10 mg / THF 5 ml
Injection volume: 20 μl

((A) Content of acid-modified vinyl group-containing epoxy resin)
In the photosensitive resin composition of the present invention, the content of the (A) acid-modified vinyl group-containing epoxy resin is preferably 5 to 60% by mass based on the total solid content of the photosensitive resin composition. More preferably, it is ˜50% by mass, and particularly preferably 15˜40% by mass. When the content of the component (A) is within the above range, a coating film that is superior in heat resistance, electrical characteristics, and chemical resistance can be obtained.

<(B) Photopolymerizable compound having an ethylenically unsaturated bond>
As the photopolymerizable compound (B) having an ethylenically unsaturated bond used in the photosensitive resin composition of the present invention, a compound having a molecular weight of 1000 or less is preferable. For example, 2-hydroxyethyl (meth) acrylate, 2 -Hydroxyalkyl (meth) acrylates such as hydroxypropyl (meth) acrylate, mono- or di (meth) acrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, N, N-dimethyl (meth) acrylamide, (Meth) acrylamides such as N-methylol (meth) acrylamide, aminoalkyl (meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate, hexanediol, trimethylolpropane, pentaerythritol, dito Polyhydric alcohols such as methylolpropane, dipentaerythritol, tris-hydroxyethyl isocyanurate, or poly (meth) acrylates of these ethylene oxide or propylene oxide adducts, phenoxyethyl (meth) acrylate, polyethoxydi (meta) of bisphenol A ) (Meth) acrylates of ethylene oxide or propylene oxide adducts of phenols such as acrylates, (meth) acrylates of glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, and melamine (Meth) acrylate, acrylamide, acrylonitrile, diacetone acrylamide, styrene, vinyl toluene, etc. It is. Moreover, it is more preferable to have three or more ethylenically unsaturated bonds in one molecule in order to increase the crosslinking density by photocuring and improve heat resistance and electrical reliability. Examples of such a compound having an ethylenically unsaturated bond include dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate. These (B) compounds having an ethylenically unsaturated group are used singly or in combination of two or more.

((B) Content of photopolymerizable compound having an ethylenically unsaturated bond)
(B) The content of the photopolymerizable compound having an ethylenically unsaturated bond is preferably 2 to 50% by mass, more preferably 3 to 30% by mass, based on the total solid content in the photosensitive resin composition. More preferably, it is 3 to 20% by mass. If it is 2% by mass or more, the photosensitivity is low, so that the tendency of the exposed portion to elute during development can be suppressed, and if it is 50% by mass or less, a decrease in heat resistance can be suppressed.

<(C) Photopolymerization initiator>
Examples of the (C) photopolymerization initiator used in the photosensitive resin composition of the present invention include benzoins such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl Acetophenones such as -1- [4- (methylthio) phenyl] -2-morpholino-1-propanone and N, N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1 -Chloroa Anthraquinones such as traquinone, 2-amylanthraquinone, 2-aminoanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; acetophenone dimethyl ketal; Ketals such as benzyldimethyl ketal; benzophenones such as benzophenone, methylbenzophenone, 4,4′-dichlorobenzophenone, 4,4′-bis (diethylamino) benzophenone, Michler's ketone, 4-benzoyl-4′-methyldiphenyl sulfide; 2 -(O-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- ( -Fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer 2,4,5 such as 2-mer, 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer -Acridines such as triarylimidazole dimers, 9-phenylacridine, 1,7-bis (9,9'-acridinyl) heptane; acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide 1,2-octanedione-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime), — [9-Ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] ethanone 1- (O-acetyloxime), 1-phenyl-1,2-propanedione-2- [O— ( Ethoxycarbonyl) oxime] and the like. These (C) photoinitiators can be used individually by 1 type or in combination of 2 or more types. Further, Irgacure 819 having good curability at the bottom for photobleaching and Irgacure 369 which is less likely to be generated as outgas because it is less volatile.

(C ′) such as tertiary amines such as N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine and the like. Photopolymerization initiation assistants can be used alone or in combination of two or more.

((C) Content of photopolymerization initiator)
The content of the photopolymerization initiator (C) in the photosensitive resin composition of the present invention is preferably 0.2 to 20% by mass, more preferably 0.4%, based on the total solid content of the photosensitive resin composition. -15% by mass, more preferably 0.6-10% by mass. Further, when the content of (C) the photopolymerization initiator is 0.2% by mass or more, the exposed portion is hardly eluted during development, and when it is 20% by mass or less, a decrease in heat resistance can be suppressed.

<(D) Inorganic filler>
Examples of the (D) inorganic filler used in the photosensitive resin composition of the present invention include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), titania (TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), Zirconia (ZrO ₂ ), silicon nitride (Si ₃ N ₄ ), barium titanate (BaO · TiO ₂ ), barium carbonate (BaCO ₃ ), magnesium carbonate, aluminum oxide, aluminum hydroxide, magnesium hydroxide, lead titanate ( PbO · TiO ₂ ), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), gallium oxide (Ga ₂ O ₃ ), spinel (MgO · Al ₂ O ₃ ), mullite (3Al ₂ O ₃ · 2SiO _2), cordierite _{(2MgO · 2Al 2 O 3 /} 5SiO 2), talc (3MgO · 4 SiO ₂ · _{H 2} O), aluminum titanate _{(TiO 2 -Al 2 O 3)} , yttria-containing zirconia _{(Y 2 O 3 -ZrO 2)} , barium silicate (BaO · 8SiO _2), boron nitride (BN), Calcium carbonate (CaCO ₃ ), barium sulfate (BaSO ₄ ), calcium sulfate (CaSO ₄ ), zinc oxide (ZnO), magnesium titanate (MgO · TiO ₂ ), hydrotalcite, mica, calcined kaolin, carbon (C) Etc. can be used. These (D) inorganic fillers can be used singly or in combination of two or more.

In order to disperse the inorganic filler (D) used in the photosensitive resin composition of the present invention in the resin without agglomeration with the primary particle size, the surface treatment was performed with a silane coupling agent as necessary. It is preferable to use one. As the silane coupling agent, generally available ones can be used, for example, alkyl silane, alkoxy silane, vinyl silane, epoxy silane, amino silane, acrylic silane, methacryl silane, mercapto silane, sulfide silane, isocyanate silane, Sulfur silane, styryl silane, alkylchlorosilane, and the like can be used. Specific compound names include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, diisopropyldimethoxysilane, isobutyltrimethoxy. Silane, diisobutyldimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, n-dodecylmethoxysilane, phenyltrimethoxysilane, diphenyldimethoxy Silane, triphenylsilanol, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, n-octyldi Tylchlorosilane, tetraethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropylmethyldimethoxysilane , 3-phenylaminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane Bis (3- (triethoxysilyl) propyl) disulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide, vinyltriacetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, Lutriisopropoxysilane, allyltrimethoxysilane, diallyldimethylsilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3 -Mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, N- (1,3-dimethylbutylidene) -3-aminopropyltriethoxysilane, aminosilane, monomethyltriisocyanate silane, tetraisocyanate silane, γ-isocyanatopropyl A triethoxysilane is mentioned. As the silane coupling agent to be used, those that react with the carboxy group of the (A) acid-modified vinyl group-containing epoxy resin contained in the photosensitive resin composition are preferable. For example, epoxy silane, acrylic silane, methacryl Silane is preferred. Since these silane coupling agents strengthen the bond between silica and resin, they increase the strength of the film when used as a permanent mask resist and contribute to crack resistance and the like in a temperature cycle test. Further, mercaptosilane or isocyanate silane may be used. (B) It is thought that it reacts with the ethylenically unsaturated group of the photopolymerizable monomer having an ethylenically unsaturated bond and exhibits the same effect as when the silane coupling agent is used.

(D) Among inorganic fillers, it is preferable to use silica fine particles from the viewpoint of improving the low expansion coefficient and heat resistance. In addition, barium sulfate fine particles are used from the viewpoint of improving solder heat resistance, HAST property (insulation reliability), crack resistance (thermal shock resistance), and adhesion strength between the underfill material and the cured film after the PCT test. It is also preferable to do. Moreover, it is preferable that the said silica fine particle is surface-treated with an alumina and / or an organosilane type compound from a viewpoint which can improve the aggregation prevention effect.

(D) The average particle diameter of the inorganic filler is preferably 0.01 to 1 μm, more preferably 0.1 to 1 μm from the viewpoint of practicality and resolution, and 0.3 to 0.7 μm. Most preferably it is. Further, (D) the inorganic filler preferably has a maximum particle size of 0.1 to 5 μm, more preferably 0.1 to 3 μm, and particularly preferably 0.1 to 1 μm. When the maximum particle size exceeds 5 μm, resolution and insulation reliability tend to be impaired.

((D) Content of inorganic filler)
In the photosensitive resin composition of the present invention, the content of the (D) inorganic filler is 30 to 60% by mass based on the total solid content of the photosensitive resin composition from the viewpoints of resolution and low thermal expansion coefficient. 30 to 55% by mass, and more preferably 35 to 50% by mass. (D) When the content of the inorganic filler is within the above range, the low thermal expansion coefficient, heat resistance, insulation reliability, thermal shock resistance, resolution, film strength and the like can be further improved. When the filling amount exceeds 60% by mass, it becomes difficult to disperse in the resin, and the flowability of the photosensitive resin composition tends to decrease. If the filling amount is less than 30% by mass, the thermal expansion coefficient is not sufficiently reduced during heating, and there is a tendency that warpage cannot be reduced, and crack resistance during reflow mounting tends to be difficult to obtain. is there.

<(E) Curing agent>
As the (E) curing agent used in the photosensitive resin composition of the present invention, a compound that cures itself by heat, ultraviolet rays, or (A) a carboxyl group, a hydroxyl group and heat of an acid-modified vinyl group-containing epoxy resin, A compound that is cured by reaction with ultraviolet rays or the like is preferable. (E) By using a hardening | curing agent, the heat resistance of the cured film formed from a photosensitive resin composition, the adhesiveness with an underfill material or a board | substrate, chemical resistance, etc. can be improved.

(E) Examples of the curing agent include thermosetting compounds such as epoxy compounds, melamine compounds, urea compounds, oxazoline compounds, and block type isocyanates. Examples of the epoxy compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, novolac type epoxy resin, bisphenol S type epoxy resin, and biphenyl type epoxy resin. And epoxy resins such as naphthalene type epoxy resin, dicyclo type epoxy resin, hydantoin type epoxy resin, heterocyclic epoxy resin such as triglycidyl isocyanurate, and bixylenol type epoxy resin. Examples of the melamine compound include triazine derivatives such as ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xylyl-S-triazine, triaminotriazine, hexa (N -Methyl) melamine, hexamethoxymelamine, hexabutoxylated melamine and the like. Examples of the urea compound include dimethylol urea. These (E) hardening | curing agents can be used individually by 1 type or in combination of 2 or more types.

(E) The curing agent cures by reacting with a carboxyl group, a hydroxyl group, and a glycidyl group with heat, ultraviolet rays, etc., from the viewpoint of further improving the heat resistance of the cured film and the adhesion to the underfill material or the substrate. It is preferable to contain a compound as an essential component. As such a compound, the said melamine compound etc. can be mentioned, for example. In particular, it is preferable to contain an epoxy resin and a melamine compound.

Further, (E) the curing agent preferably contains an epoxy compound (epoxy resin) and / or a block type isocyanate from the viewpoint of further improving the heat resistance of the cured film, and the epoxy compound and the block type isocyanate. It is more preferable to use together.

As the block type isocyanate, an addition reaction product of a polyisocyanate compound and an isocyanate blocking agent is used. Examples of the polyisocyanate compound include tolylene diisocyanate, xylylene diisocyanate, phenylene diisocyanate, naphthylene diisocyanate, bis (isocyanate methyl) cyclohexane, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, and isophorone diisocyanate. Polyisocyanate compounds, and adducts, burettes and isocyanurates of these.

Examples of the isocyanate blocking agent include phenolic blocking agents such as phenol, cresol, xylenol, chlorophenol and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-palerolactam, γ-butyrolactam and β-propiolactam; Active methylene blocking agents such as ethyl acetoacetate and acetylacetone; methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, benzyl Ether, methyl glycolate, butyl glycolate, diacetone alcohol, lactic acid Alcohol blocking agents such as chill and ethyl lactate; oxime blocking agents such as formaldehyde oxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, cyclohexane oxime; butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, Mercaptan block agents such as methylthiophenol and ethylthiophenol; Acid amide block agents such as acetic acid amide and benzamide; Imide block agents such as succinimide and maleic imide; Amines such as xylidine, aniline, butylamine and dibutylamine Blocking agents; imidazole blocking agents such as imidazole and 2-ethylimidazole; imine blocking agents such as methyleneimine and propyleneimine It is.

((E) Curing agent content)
(E) A hardening | curing agent is used individually by 1 type or in combination of 2 or more types. (E) The content of the curing agent is preferably 2 to 40% by mass, more preferably 3 to 30% by mass based on the total solid content of the photosensitive resin composition, and more preferably 5 to 20% by mass. % Is particularly preferred. (E) By setting the content of the curing agent in the range of 2 to 40% by mass, the heat resistance of the cured film to be formed is further improved while maintaining good developability, and the permanent mask resist Peeling between the substrates can be prevented.

In the photosensitive resin composition of the present invention, the content of the (E) curing agent per 100 parts by mass of the (A) acid-modified vinyl group-containing epoxy resin is 75 to 140 parts by mass, preferably 75. Is 135 parts by mass, more preferably 80-130 parts by mass. When the content of the (E) curing agent per 100 parts by mass of the component (A) is less than 75 parts by mass, the improvement in adhesion to the underfill material and the substrate and chemical resistance tends to be insufficient.

In addition, (E) the curing agent preferably contains an epoxy resin and a melamine compound as essential components. From the viewpoint of improving adhesion to the underfill material and the substrate and chemical resistance, the content of the epoxy resin Is preferably 15 to 100 parts by weight, more preferably 20 to 90 parts by weight, still more preferably 25 to 80 parts by weight per 100 parts by weight of the (A) acid-modified vinyl group-containing epoxy resin. The content of the melamine compound is preferably 15 to 100 parts by mass per 100 parts by mass of the (A) acid-modified vinyl group-containing epoxy resin from the viewpoint of improving adhesion to the underfill material and the substrate and chemical resistance. More preferably, it is 20 to 90 parts by mass, and further preferably 25 to 80 parts by mass.

<Other ingredients>
In addition to the components (A) to (E) described above, the photosensitive resin composition of the present invention includes (F) a pigment, (G) an elastomer, (H) an epoxy resin curing agent, (I) It may further contain a plastic resin, other additives and the like. Hereinafter, each component will be described.

<(F) Pigment>
The photosensitive resin composition of the present invention preferably contains (F) a pigment in order to improve the identification and appearance of the production apparatus. (F) The pigment is preferably used according to a desired color when the wiring is concealed. As the pigment (F), a colorant that develops a desired color may be appropriately selected and used. For example, phthalocyanine blue, phthalocyanine green, iodin green, diazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black A known colorant such as is preferred.

((F) Pigment content)
When using the (F) pigment, the content of the (F) pigment is preferably 0.1 to 10% by mass, based on the total solid content in the photosensitive resin composition, from the viewpoint of concealing the wiring. More preferably, the content is 0.1 to 5% by mass, and still more preferably 0.5 to 3% by mass.

<(G) Elastomer>
Moreover, it is preferable that the photosensitive resin composition of this invention further contains (G) elastomer. (G) By containing an elastomer, the flexibility of the cured film formed from the photosensitive resin composition, the underfill material, the adhesion to the substrate, and the like can be further improved. That is, by adding the (G) elastomer to the photosensitive resin composition of the present invention, the crosslinking reaction (curing reaction) proceeds by ultraviolet rays or heat, so that the (A) acid-modified vinyl group-containing epoxy resin is cured and contracted. Thus, the problem that distortion (internal stress) is applied to the inside of the resin and flexibility and adhesiveness are reduced can be solved.

Examples of (G) elastomers include styrene elastomers, olefin elastomers, urethane elastomers, polyester elastomers, polyamide elastomers, acrylic elastomers, and silicone elastomers. These (G) elastomers are composed of a hard segment component and a soft segment component. In general, the former contributes to heat resistance and strength, and the latter contributes to flexibility and toughness.

Examples of the styrene elastomer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, and styrene-ethylene-propylene-styrene block copolymer.

As a component constituting the styrene-based elastomer, styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene and the like can be used in addition to styrene. More specifically, Tufprene, Sorprene T, Asaprene T, Tuftec (trade name, manufactured by Asahi Kasei Co., Ltd.), Elastomer AR (trade name, manufactured by Aron Kasei Co., Ltd.), Kraton G, Califlex (above, Shell Japan) Co., Ltd., product name), JSR-TR, TSR-SIS, Dynalon (above, JSR JSR Co., Ltd., product name), Denka STR (Denka Co., Ltd., product name), Quintac (Nihon Zeon Co., Ltd., Product name), TPE-SB series (commercial name, manufactured by Sumitomo Chemical Co., Ltd.), Lavalon (commercial name, manufactured by Mitsubishi Chemical Co., Ltd.), Septon, Hibler (above, product name manufactured by Kuraray Co., Ltd.), Sumiflex (Sumitomo) Bakelite Co., Ltd., trade name), Rheostomer, Actimer (above, Riken Vinyl Industry Co., Ltd., trade name), etc. It can be used.

The olefin elastomer is a copolymer of α-olefin having 2 to 20 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-pentene. Specific examples thereof include ethylene-propylene copolymer (EPR), ethylene-propylene-diene copolymer (EPDM), dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene, butadiene, Examples thereof include carboxy-modified NBR in which methacrylic acid is copolymerized with a non-conjugated diene having 2 to 20 carbon atoms such as isoprene, an α-olefin copolymer, and a butadiene-acrylonitrile copolymer. More specifically, ethylene / α-olefin copolymer rubber, ethylene / α-olefin / non-conjugated diene copolymer rubber, propylene / α-olefin copolymer rubber, butene / α-olefin copolymer rubber Can be mentioned. Specifically, Miralastoma (Mitsui Petrochemical Co., Ltd., trade name), EXACT (Exxon Chemical Co., trade name), ENGAGE (Dow Chemical Co., Ltd.), hydrogenated styrene-butadiene rubber DYNABON HSBR ( JSR Corporation, trade name), butadiene-acrylonitrile copolymer NBR series (JSR Corporation, trade name), or both terminal carboxyl group-modified butadiene-acrylonitrile copolymer XER series (JSR Corporation, trade name) BF-1000 (trade name, manufactured by Nippon Soda Co., Ltd.), PB-3600 (trade name, manufactured by Daicel Corporation), and the like, which are partially epoxidized polybutadiene.

Urethane elastomers are composed of structural units consisting of a hard segment composed of low-molecular glycol and diisocyanate, and a soft segment composed of high-molecular (long-chain) diol and diisocyanate.

As the low-molecular glycol, for example, short-chain diols such as ethylene glycol, propylene glycol, 1,4-butanediol, bisphenol A and the like can be used. The number average molecular weight of the short chain diol is preferably 48 to 500.

Examples of the polymer (long chain) diol include polypropylene glycol, polytetramethylene oxide, poly (1,4-butylene adipate), poly (ethylene / 1,4-butylene adipate), polycaprolactone, and poly (1,6 -Hexylene carbonate) and poly (1,6-hexylene neopentylene adipate). The number average molecular weight of the polymer (long chain) diol is preferably 500 to 10,000.

Specific examples of urethane-based elastomers include PANDEX T-2185, T-2983N (trade name, manufactured by DIC Corporation), and sylactolan E790 (trade name).

Examples of the polyester elastomer include those obtained by polycondensation of a dicarboxylic acid or a derivative thereof and a diol compound or a derivative thereof.

Specific examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and aromatic dicarboxylic acids in which hydrogen atoms of these aromatic nuclei are substituted with methyl groups, ethyl groups, phenyl groups, and the like, Examples thereof include aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid and dodecanedicarboxylic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. These compounds can be used individually by 1 type or in combination of 2 or more types.

Specific examples of the diol compound include fats such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, and 1,4-cyclohexanediol. Group diol and alicyclic diol, or dihydric phenol represented by the following general formula (4).

[General Formula (4), Y ¹¹ represents an alkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 4 to 8 carbon atoms, —O—, —S—, or —SO ₂ —, wherein R ²¹ and R ²² each independently represents a halogen atom or an alkyl group having 1 to 12 carbon atoms, p and q each independently represents an integer of 0 to 4, and r represents an integer of 0 or 1. ]

Specific examples of the dihydric phenol represented by the general formula (4) include bisphenol A, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-3-methylphenyl) propane, and resorcin. These compounds can be used individually by 1 type or in combination of 2 or more types.

Also, a multi-block copolymer having an aromatic polyester (for example, polybutylene terephthalate) portion as a hard segment component and an aliphatic polyester (for example, polytetramethylene glycol) portion as a soft segment component can be used. There are various grades depending on the type, ratio, and molecular weight of the hard and soft segments. Specific examples include Hytrel (trade name, manufactured by Toray DuPont Co., Ltd.), Perprene (trade name, manufactured by Toyobo Co., Ltd.), Espel (trade name, manufactured by Hitachi Chemical Co., Ltd.), and the like.

Polyamide elastomers are broadly classified into two types: polyether block amide type and polyether ester block amide type using polyamide for the hard segment and polyether or polyester for the soft segment.

As the polyamide, polyamide-6, 11, 12 or the like can be used. As the polyether, polyoxyethylene, polyoxypropylene, polytetramethylene glycol, or the like can be used. Specifically, UBE polyamide elastomer (product name, manufactured by Ube Industries, Ltd.), Daiamide (product name, manufactured by Daicel Evonik Co., Ltd.), PEBAX (product name, manufactured by Toray Industries, Inc.), Grilon ELY (MS Japan Co., Ltd.) Product, trade name), nopamid (trade name, manufactured by Mitsubishi Chemical Corporation), gleasing (trade name, manufactured by DIC Corporation) and the like can be used.

As the acrylic elastomer, an acrylic ester is a main component, and ethyl acrylate, butyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, or the like is used. Moreover, glycidyl methacrylate, allyl glycidyl ether, etc. can be used as a crosslinking point monomer. Furthermore, acrylonitrile and ethylene can be copolymerized. Specifically, an acrylonitrile-butyl acrylate copolymer, an acrylonitrile-butyl acrylate-ethyl acrylate copolymer, an acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer, or the like can be used.

Silicone elastomers are composed mainly of organopolysiloxane, for example, and are classified into polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane. Some are modified with vinyl groups, alkoxy groups, and the like. Specific examples include KE series (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), SE series, CY series, SH series (above, trade name by Toray Dow Corning Co., Ltd.), and the like.

In addition to the above-described elastomer, a rubber-modified epoxy resin can also be used. The rubber-modified epoxy resin includes, for example, a part or all of the epoxy groups of the bisphenol F type epoxy resin, bisphenol A type epoxy resin, salicylaldehyde type epoxy resin, phenol novolac type epoxy resin or cresol novolac type epoxy resin. It can be obtained by modification with terminal carboxylic acid-modified butadiene-acrylonitrile rubber, terminal amino-modified silicone rubber or the like. Among these elastomers, in terms of shear adhesion, both end carboxyl group-modified butadiene-acrylonitrile copolymer, Espel which is a polyester elastomer having a hydroxyl group (Espel 1612, 1620, trade name, manufactured by Hitachi Chemical Co., Ltd.) Epoxidized polybutadiene, etc. are preferred. An elastomer that is liquid at room temperature is particularly preferred.

((G) Elastomer content)
When the elastomer (G) is used, its content is preferably 1 to 20% by mass, more preferably 2 to 15% by mass, based on the total solid content of the photosensitive resin composition. It is particularly preferable that the content be ˜10% by mass. (G) By setting the elastomer content in the range of 1 to 20% by mass, the thermal shock resistance and the adhesive strength between the underfill material and the cured film can be further improved while maintaining good developability. it can. Moreover, when using for a thin film substrate, the curvature property of a thin film substrate can be reduced.

<(H) Epoxy resin curing agent>
In the photosensitive resin composition of the present invention, (H) an epoxy resin curing agent can be added for the purpose of further improving various properties such as heat resistance, adhesion, and chemical resistance of the cured film to be formed. .

Specific examples of such (H) epoxy resin curing agent include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, 2-phenyl-4- Imidazole derivatives such as methyl-5-hydroxymethylimidazole; guanamines such as acetoguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, polybasic hydrazide Polyamines such as these organic acid salts and / or epoxy adducts: amine complexes of boron trifluoride; trimethylamine, triethanolamine, N, N-dimethyloctylamine, N-benzyldimethylamine, Tertiary amines such as lysine, N-methylmorpholine, hexa (N-methyl) melamine, 2,4,6-tris (dimethylaminophenol), tetramethylguanidine, m-aminophenol; polyvinylphenol, polyvinylphenol bromide Polyphenols such as phenol novolac and alkylphenol novolac; organic phosphines such as tributylphosphine, triphenylphosphine and tris-2-cyanoethylphosphine; tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide, hexadecyltributylphosphine Phosphonium salts such as nium chloride; quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride; the above-mentioned polybasic acid anhydrides; E sulfonyl iodonium tetrafluoroborate, triphenyl sulfonium hexafluoroantimonate, 2,4,6-triphenyl-thio pyrylium hexafluorophosphate, and the like. These (G) epoxy resin hardening | curing agents are used individually by 1 type or in combination of 2 or more types.

(Content of (H) epoxy resin curing agent)
When (H) an epoxy resin curing agent is used, its content is preferably 0.01 to 20% by mass, based on the total solid content of the photosensitive resin composition, preferably 0.1 to 10% by mass. More preferably.

<(I) Thermoplastic resin>
Moreover, in order to further improve the flexibility of the cured film, (I) a thermoplastic resin can be added to the photosensitive resin composition of the present invention.

(I) Examples of the thermoplastic resin include acrylic resin and urethane resin. (I) The content in the case of containing a thermoplastic resin is preferably 1 to 30% by mass, more preferably 5 to 20% by mass based on the total solid content of the photosensitive resin composition. .

<Other additives>
Furthermore, in the photosensitive resin composition of the present invention, if necessary, organic fine particles such as melamine and organic bentonite, polymerization inhibitors such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol and pyrogallol, benton, montmorillonite and the like. Various commonly known additives such as thickeners, silicone-based, fluorine-based and vinyl resin-based antifoaming agents, silane coupling agents, and diluents can be added. Furthermore, flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, antimony compounds, phosphate compounds of phosphorous compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters can also be added.

As the diluent, for example, an organic solvent can be used. Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, Glycol ethers such as dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether and triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate, aliphatic carbonization such as octane and decane Examples thereof include petroleum solvents such as hydrogen, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. A diluent is used individually by 1 type or in combination of 2 or more types. Content in the case of using a diluent can be suitably adjusted from a viewpoint of the applicability | paintability of the photosensitive resin composition.

The photosensitive resin composition of the present invention can be obtained by uniformly kneading and mixing the above-described components with a roll mill, a bead mill or the like.

[Production of cured film and cured film]
The cured film of the present invention is a cured film formed by curing the photosensitive resin composition of the present invention, and is usually formed as a patterned pattern cured film. This pattern cured film is formed by, for example, applying a photosensitive resin composition of the present invention on a substrate such as a copper clad laminate and drying to form a coating film, and irradiating the coating film with active light to form a pattern. The pattern resin film can be produced by sequentially performing a step of exposing to a shape, a step of removing an unexposed portion by development to obtain a pattern resin film, and a step of curing the pattern resin film.

In one embodiment, the photosensitive resin composition of the present invention can be used, for example, to form an image as follows and to produce a cured film such as a permanent mask resist.

That is, it is applied to a substrate such as a copper-clad laminate by a screen printing method, a spray method, a roll coating method, a curtain coating method, an electrostatic coating method or the like with a film thickness of 10 to 200 μm, and then a coating film is applied. After drying at ˜110 ° C., the negative film is brought into direct contact (or non-contact through a transparent film) and active light (eg, ultraviolet light) is preferably applied at an exposure dose of 10 to 1,000 mJ / cm ^2. After that, the unexposed portion is dissolved and removed (developed) with a dilute alkaline aqueous solution or an organic solvent to obtain a patterned resin film. Next, the patterned resin film as an exposed portion is sufficiently cured by post-exposure (ultraviolet light exposure) and / or post-heating to obtain a cured film. The post-exposure is preferably performed at an exposure amount of 1 to 5 J / cm ² , for example, and the post-heating is preferably performed at 100 to 200 ° C. for 30 minutes to 12 hours.

[Photosensitive element]
Moreover, the photosensitive resin composition of this invention can also be laminated | stacked on a support body, and it can also be set as a photosensitive element. The photosensitive element of this invention has a support body and the photosensitive layer which uses the photosensitive resin composition of this invention on this support body, for example. The thickness of the layer made of the photosensitive resin composition is not particularly limited, but is preferably 10 to 100 μm. Examples of the support include polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polyolefins such as polypropylene and polyethylene. The thickness of the support is not particularly limited, but is preferably in the range of 5 to 100 μm. The photosensitive layer made of the photosensitive resin composition is preferably formed by applying and drying a solution of the photosensitive resin composition on a support.
The coating film can be dried using hot air drying, a far infrared ray, or a dryer using near infrared rays. The drying temperature is, for example, preferably 60 to 120 ° C., more preferably 70 to 110 ° C., More preferably, it is 80 to 100 ° C. The drying time is, for example, preferably 1 to 60 minutes, more preferably 2 to 30 minutes, and further preferably 5 to 20 minutes.

In the photosensitive element of the present invention, a protective layer can be laminated on the surface of the photosensitive layer opposite to the surface in contact with the support. As the protective layer, for example, a polymer film such as polyethylene or polypropylene may be used. Moreover, the polymer film similar to the carrier film mentioned above may be used, and a different polymer film may be used.

[Printed wiring board]
The printed wiring board of this invention comprises the permanent mask resist formed with the photosensitive resin composition of this invention.
The permanent mask resist formed from the photosensitive resin composition of the present invention has high rigidity and excellent adhesion to the substrate and the underfill material, so that removal of the permanent mask resist and wiring board warpage are eliminated. A printed wiring board can be obtained.

[Method of manufacturing printed wiring board]
In the method for producing a printed wiring board of the present invention, a photosensitive layer is provided on a substrate, for example, a metal-clad laminate such as a copper-clad laminate using the photosensitive resin composition of the present invention or the photosensitive element of the present invention. A step, a step of forming a resist pattern using the photosensitive layer, and a step of forming a permanent mask resist by curing the resist pattern. The details of each step are as described in the above-mentioned items “Creating cured film” and “Photosensitive element”.

Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples.

[Synthesis Example 1: Production of acid-modified vinyl group-containing epoxy resin (A-1)]
Bisphenol F novolac type epoxy resin having a structural unit represented by the above general formula (3) (R ¹⁴ = hydrogen atom, Y ⁶ and Y ⁷ = glycidyl group) (trade name: EXA-7376, manufactured by DIC Corporation, epoxy) Equivalent: 186) 350 parts by weight, 70 parts by weight of acrylic acid, 0.5 parts by weight of methylhydroquinone, 120 parts by weight of carbitol acetate were added and reacted by heating and stirring at 90 ° C. to completely dissolve the mixture. . Next, the obtained solution was cooled to 60 ° C., 2 parts by mass of triphenylphosphine was added, and the mixture was heated to 100 ° C. until the acid value of the solution reached 1 mgKOH / g, and the resin (A ′) was A solution containing was obtained. To the solution after the reaction, 98 parts by mass of tetrahydrophthalic anhydride (THPAC) and 85 parts by mass of carbitol acetate were added, heated to 80 ° C., reacted for about 6 hours, cooled, and the solid content was 73 parts by mass. % THPAC-modified bisphenol F type novolak epoxy acrylate (hereinafter referred to as “acid-modified vinyl group-containing epoxy resin (A-1)”; acid value: 75 mgKOH / g, weight average molecular weight: 10,000) A solution was obtained.

(Examples 1 to 3, Comparative Examples 1 to 4)
Each material shown in the following Table 1 was blended in the blending amount (unit: parts by mass) shown in the same table, then kneaded with a three-roll mill, and carbitol acetate was added so that the solid content concentration became 70% by mass. A photosensitive resin composition was obtained. In addition, the compounding quantity of each material in following Table 1 shows the compounding quantity of solid content.

The details of each material in Table 1 are as follows.
* 1 (Acid-modified vinyl group-containing epoxy resin (A-1)): THPAC-modified bisphenol F type novolak epoxy acrylate prepared in Synthesis Example 1 * 2 (Aronix M402): Dipentaerythritol hexaacrylate (manufactured by Toagosei Co., Ltd.) Product name)
* 3 (Irgacure 369): 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.)
* 4 (SFP-20M): Silica fine particles (trade name, manufactured by Denki Kagaku Kogyo Co., Ltd.)
* 5 (ASA): Barium sulfate fine particles (manufactured by Sakai Chemical Industry Co., Ltd., trade name)
* 6 (YSLV-80XY): Epoxy resin (Novolac type epoxy resin, manufactured by Nippon Steel Chemical Co., Ltd., trade name)
* 7 (RE-306): Epoxy resin (trade name, manufactured by Nippon Kayaku Co., Ltd.)
* 8 (PB-3600): Epoxidized polybutadiene (trade name, manufactured by Daicel Chemical Industries, Ltd.)

The details of the contents of (D) inorganic filler and (E) curing agent in the photosensitive resin compositions of Examples 1 to 3 and Comparative Examples 1 to 4 are as shown in Table 2 below.

[warp]
The photosensitive resin compositions of Examples and Comparative Examples were screen printed on a copper-clad laminate (E-700G, manufactured by Hitachi Chemical Co., Ltd.) having a size of 74 mm × 240 mm so that the film thickness after drying was 15 μm. After the application, it was dried at 75 ° C. for 30 minutes using a hot air circulation dryer. The surface of the obtained coating film was irradiated with ultraviolet rays having an integrated exposure amount of 100 mJ / cm ² and developed with a 1% by mass aqueous sodium carbonate solution for 60 seconds. Next, it exposed with the exposure amount of 2000 mJ / cm < ² > using the ultraviolet-ray exposure apparatus, and heated at 170 degreeC for 1 hour, and produced the test piece. The warpage of the substrate was evaluated as “X” at 2 mm or more and “◯” at 2 mm or less, with the most warped portions at the four corners of the substrate. The evaluation results are shown in Table 3.

[Peeling]
The surface of the test piece used for warpage evaluation was observed with a metal microscope (magnification 100 times, bright field) with 5 visual fields. When there was peeling between the photosensitive resin composition and the substrate, “x”, and when there was no peeling, “○” evaluated. The evaluation results are shown in Table 3.

As is apparent from Table 3, it can be seen that Examples 1 to 3 are excellent in evaluation of warpage and peeling and excellent in high rigidity. On the other hand, as is clear from Table 2, it can be seen that Comparative Examples 1 to 4 are insufficient in warping or peeling. Therefore, according to the present invention, it is possible to improve warpage even when used for forming a permanent mask resist of a thin printed wiring board, and there is no peeling between the permanent mask resist and the substrate. A composition is obtained.

Claims (13)

1. (A) acid-modified vinyl group-containing epoxy resin, (B) a photopolymerizable monomer having an ethylenically unsaturated bond, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a curing agent containing a melamine compound. And (D) the content of the inorganic filler is 30 to 60% by mass of the total solid content in the photosensitive resin composition, and (E) the curing agent A photosensitive resin composition having a content of 75 to 140 parts by mass per 100 parts by mass of (A) an acid-modified vinyl group-containing epoxy resin.
2. The (A) acid-modified vinyl group-containing epoxy resin is synthesized using a novolac-type epoxy resin having a structural unit represented by the following general formula (1), the following general formula (2 And bisphenol novolac epoxy resin having a structural unit represented by the following general formula (3) and an acid-modified vinyl group-containing epoxy resin synthesized using a bisphenol novolac epoxy resin having a structural unit represented by The photosensitive resin composition according to claim 1, comprising at least one selected from the group consisting of an acid-modified vinyl group-containing epoxy resin to be synthesized.
   

   

   [In the general formula (1), R ¹¹ represents a hydrogen atom or a methyl group, Y ¹ represents a hydrogen atom or a glycidyl group, and the novolac epoxy resin having a structural unit represented by the general formula (1) The molar ratio of hydrogen atom to glycidyl group (hydrogen atom / glycidyl group) is 0/100 to 30/70. ]
   

   

   [In General Formula (2), two R ^{12 s} each independently represent a hydrogen atom or a methyl group; two Y ^{2 s} each independently represent a hydrogen atom or a glycidyl group; and two R ^{12 s} are the same or different. Provided that at least one of Y ² represents a glycidyl group. ]
   

   

   [In the general formula (3), two R ^{13 s} each independently represent a hydrogen atom or a methyl group, two Y ^{3 s} each independently represent a hydrogen atom or a glycidyl group, and the two R ^{13 s} are the same or different. Provided that at least one of Y ³ represents a glycidyl group. ]
3. The (A) acid-modified vinyl group-containing epoxy resin has a novolak type epoxy resin having a structural unit represented by the general formula (1), and a bisphenol novolak type epoxy having a structural unit represented by the general formula (2). At least one epoxy resin (a) selected from the group consisting of a resin and a bisphenol novolac type epoxy resin having a structural unit represented by the general formula (3), and a vinyl group-containing monocarboxylic acid (b). The photosensitive resin composition of Claim 2 which is resin formed by making the resin (A ') made to react react with a saturated or unsaturated group containing polybasic acid anhydride (c).
4. (E) The curing agent contains a compound that cures by reacting with a carboxyl group and a hydroxyl group, and a compound that reacts and cures with a carboxyl group, a hydroxyl group, and a glycidyl group. The photosensitive resin composition according to item.
5. (E) The curing agent contains an epoxy resin and a melamine compound, and (E) the content of the epoxy resin in the curing agent is (A) 15 to 100 masses per 100 mass parts of the acid-modified vinyl group-containing epoxy resin. The photosensitive resin composition according to claim 4, wherein the content of the melamine compound in the curing agent (E) is 15 to 100 parts by mass per 100 parts by mass of the (A) acid-modified vinyl group-containing epoxy resin.
6. (B) The photopolymerizable monomer having an ethylenically unsaturated bond is a polyfunctional photopolymerizable monomer having three or more ethylenically unsaturated bonds in one molecule. Photosensitive resin composition.
7. The photosensitive resin composition according to any one of claims 1 to 6, further comprising (F) a pigment.
8. The photosensitive resin composition according to any one of claims 1 to 7, further comprising (G) an elastomer.
9. A pattern cured film formed from the photosensitive resin composition according to any one of claims 1 to 8.
10. A step of applying and drying the photosensitive resin composition according to any one of claims 1 to 8 on a substrate to form a coating film, a step of irradiating the coating film with active light and exposing to a pattern A method for producing a cured pattern film, comprising: removing a non-exposed portion by development to obtain a patterned resin film; and curing the patterned resin film.
11. A photosensitive element comprising: a support; and a photosensitive layer formed using the photosensitive resin composition according to any one of claims 1 to 8 on the support.
12. A printed wiring board comprising a permanent mask resist formed from the photosensitive resin composition according to any one of claims 1 to 8.
13. A step of forming a photosensitive layer on the substrate using the photosensitive resin composition according to any one of claims 1 to 8 or the photosensitive element according to claim 11, using the photosensitive layer. A method for manufacturing a printed wiring board, comprising: a step of forming a resist pattern; and a step of curing the resist pattern to form a permanent mask resist.