JP2014182347A - Alkali development type photosensitive resin composition and cured product of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive thermosetting resin composition suitable for forming a film having such properties that a cured film formed from the composition, for an alkali-developable solder resist or an insulating film used in a printed wiring board, is free from cracks during a reflow process of a solder and that the film is excellent in dry-to-touch property, alkali developing property, hardness, solvent resistance, and adhesiveness to a substrate.SOLUTION: An alkali development type photosensitive resin composition is provided, which comprises (A) an acid anhydride adduct of epoxy acrylate, (B) a phenol novolac type epoxy resin modified with an agent for producing an aralkyl group such as styrene, (C) a photopolymerizable monomer or oligomer, and (D) a photopolymerization initiator or a sensitizer.

Description

  The present invention relates to an alkali-developable photosensitive resin composition that gives a cured product that is excellent in developability and also has excellent adhesion and solder heat resistance, and a cured product thereof. Suitable for permanent protective film such as insulation coating, solder resist ink, correlated insulation material for build-up substrates, etc., or solder resist ink that can be developed with dilute alkaline solution suitable for manufacturing printed wiring boards, especially flexible printed wiring boards Used for.

  Currently, printed wiring boards are manufactured by soldering for the purpose of protecting solder from adhering to unnecessary parts when electronic components are mounted on a printed wiring board by soldering after forming a wiring (circuit) pattern. A protective layer called a mask is coated. In addition, a multilayer wiring board (build-up board) in which insulating films are stacked while sequentially forming wiring circuits is often used.

  The heat-resistant insulating material used in the manufacture of printed wiring boards for IC packages such as BGA and CSP using these printed wiring boards and sealing resins is ultraviolet curable, or thermosetting, or a liquid that uses ultraviolet curing and thermosetting together. There are types that apply solder resist ink on a printed wiring board by a printing method such as screen printing, and types that obtain a film by attaching a dry film resist to a printed wiring board and peeling the support, etc. From the viewpoint of high accuracy and high density, the type that uses both UV curing and heat curing is the mainstream. After photocuring by UV irradiation, a pattern is formed by developing with a dilute alkaline aqueous solution, and then a film is obtained by further heat curing. ing.

  Resist which has a phenol novolac type acid-modified epoxy acrylate compound (meaning an acid anhydride adduct of epoxy acrylate) and an epoxy compound as an essential component as a conventional commercially available alkaline development type liquid resist for the printed wiring board. When the ink (Patent Documents 1 and 2) is applied, the cured film has a problem in crack resistance such that cracks occur during a reflow process during package mounting or during a thermal cycle test, and improvement is required.

  Various attempts have been made to deal with such problems. For example, a method of modifying a phenol novolac type acid-modified epoxy acrylate compound (Patent Document 3) or a method of reacting a new epoxy compound (Patent Document) 4) is being studied. However, these resist inks have problems such as low sensitivity to ultraviolet rays, unsatisfactory resolution, and insufficient PCT (pressure cooker test) resistance, which is one of long-term reliability tests, The development life during the solvent drying process of the film is remarkably short, and it is difficult to form a wiring pattern on the printed wiring board.

  Thus, when flexibility is imparted to a cured film formed to solve crack resistance, generally either alkali developability or PCT resistance is greatly reduced, and further, the development life in the solvent drying step And the dryness of the touch after the solvent drying process is reduced, and the basic performance as a resist ink is dryness to the touch of the film, alkali developability, development life, PCT resistance, solder heat resistance, It is extremely difficult to completely solve the problem of cracks in the cured film that occurs in the thermal cycle test during mounting and in the long-term reliability test, with a good balance of adhesion, plating properties, electrical insulation, etc. The current situation is that there is nothing to satisfy. In addition, an aromatic-modified phenol novolac type epoxy resin is known, but an alkali-developable resin composition and a cured product thereof have not been studied (Patent Document 5).

JP-A 61-243869 Japanese Patent Laid-Open No. 3-253093 Japanese Patent Laid-Open No. 11-288091 JP 2003-026762 A JP 2010-235819 A

  Accordingly, an object of the present invention is to manufacture printed wiring boards, particularly ICs such as BGA (ball grid array) and CSP (chip scale package) using a printed wiring board with a solder resist and a sealing resin. In the field of electronic materials such as liquid solder resist inks and dry film resists used in the manufacture of packages, dryness to the touch, alkali developability, hardness, and solvent resistance do not cause cracks during solder reflow. Furthermore, it is providing the photosensitive thermosetting resin composition containing the acid anhydride adduct of the epoxy acrylate suitable for film formation excellent in adhesiveness with a base material, and an epoxy compound.

That is, the present invention
(A) an acid anhydride adduct of epoxy acrylate,
(B) an epoxy resin represented by the following general formula (1),
(C) A photopolymerizable monomer or oligomer, and (D) a photopolymerization initiator or sensitizer, which is an alkali development type photosensitive resin composition.

（ここで、Ｇはグリシジル基を示し、Ｒ₁は水素又は炭素数１〜６の炭化水素基を示し、Ｒ₂は下記式（ａ）で表されるアラルキル基を示し、ｎは１〜２０の数を示す。また、ｐは０．１〜２．５の数を示す。）

（ここで、Ｒ₃〜Ｒ₅は水素原子又は炭素数１〜６の炭化水素基を示す。）

(Here, G represents a glycidyl group, R ₁ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, R ₂ represents an aralkyl group represented by the following formula (a), and n represents 1 to 20) In addition, p represents a number of 0.1 to 2.5.)

(Here, R _{3 to} R ₅ represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.)

  Moreover, this invention is the hardened | cured material which hardened the said alkali image development type photosensitive resin composition.

  According to the present invention, the resin composition is excellent in dryness to the touch and alkali developability, and the cured resin does not cause cracks during solder reflow, and has excellent hardness, solvent resistance, and adhesion to the substrate. Since it is excellent, it is suitable not only for a solder resist of a printed wiring board but also as an interlayer insulating film for a chip mounting substrate such as a build-up substrate or a CSP.

Hereinafter, the present invention will be described in detail.
First, (A) an acid anhydride adduct of epoxy acrylate (hereinafter also referred to as component (A)) constituting the photosensitive resin composition of the present invention is known in the above-mentioned patent documents and the like. It can be produced by a method as described in JP-A-7-3122.

  The acid anhydride adduct of epoxy acrylate, for example, reacts with an epoxy resin and (meth) acrylic acid (meaning acrylic acid, methacrylic acid or both) to form an epoxy acrylate resin, and this reacts with acid anhydrides Can be manufactured. Here, among (meth) acrylic acids, acrylic acid is preferable. Acrylic acid and methacrylic acid may be used in combination. The reaction is usually performed in the range of 50 ° C. to 150 ° C. for 1 hour to 20 hours. The use ratio of the epoxy resin and (meth) acrylic acid may be such that the molar ratio of the epoxy group and the carboxyl group is an equimolar ratio or the vicinity thereof (preferably 0.8 to 1.2). Good.

  Examples of the epoxy resin and epoxy acrylate resin used as the raw material for the acid anhydride adduct of epoxy acrylate include novolac epoxy resins such as phenol novolac epoxy resin, cresol novolac epoxy resin, naphthol novolac epoxy resin, and phenol aralkyl epoxy. Resin, aralkyl epoxy resin such as naphthol aralkyl epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, fluorene bisphenol type epoxy resin, bisphenol type epoxy resin such as diphenyl ether type epoxy resin, biphenyl There are epoxy resins such as type epoxy resin or alicyclic epoxy resin. Examples of the epoxy acrylate resin include those obtained by adding acrylic acid or methacrylic acid to these epoxy resins. The epoxy acrylate resin has an OH group generated by a reaction between an epoxy group and (meth) acrylic acid. An acid anhydride adduct of epoxy acrylate is obtained from these epoxy acrylate resins and acid anhydrides.

  Examples of the acid anhydrides to be reacted with the epoxy acrylate resin include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and methylendomethylenetetrahydrophthalic anhydride. , Chlorendic anhydride, methyltetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, biphenyl ether tetracarboxylic dianhydride, and the like. A monoanhydride and a dianhydride may be used in combination, and the molar ratio may be changed in the range of 1/99 to 99/1.

  The acid anhydride adduct of epoxy acrylate reacts with the OH group of the epoxy acrylate resin and acid anhydrides to form an ester bond and has a carboxy group derived from acid anhydrides. Gives solubility. For example, when acid monoanhydride is used, the —OH group is esterified to form —OOC—Ar—COOH group. Here, Ar is a residue of acid monoanhydride. The reaction of the acid anhydrides of the epoxy acrylate resin causes at least a part of the OH groups to form an ester bond with the acid anhydrides to form an acid anhydride adduct, but 10% or more of the OH groups, preferably 50 It is better to react ~ 100%. The modification rate of OH groups is related to the abundance of carboxy groups, whereby alkali solubility can be adjusted and alkali developability can be optimized.

  Next, the epoxy resin (hereinafter also referred to as StPNE or (B) component) represented by the general formula (1) constituting the photosensitive resin composition of the present invention will be described.

In the general formula (1), G represents a glycidyl group, R ₁ is a hydrocarbon group having 1 to 6 carbon hydrogen or carbon. R ₁ is preferably hydrogen, an alkyl group having 1 to 6 carbon atoms, or a phenyl group, more preferably hydrogen or a methyl group. R ₂ represents an aralkyl group represented by the formula (a), and n represents a number of 1 to 20. The number average is preferably in the range of 1-10. R < ₃ > -R < ₅ > shows a hydrogen atom or a C1-C6 hydrocarbon group. p shows the number of 0.1-2.5 as an average. Here, the average means the average of the number of R ₂ present per benzene ring to which the aralkyl group R ₂ of the formula (a) is bonded.

  StPNE is preferably obtained by epoxidizing an aralkyl group-added polyvalent hydroxy resin (also referred to as StPN) represented by the following general formula (3). Typically, it is a styrene-added polyvalent hydroxy resin. In addition, StPN represented by the general formula (3) causes an addition reaction of a polyvalent hydroxy compound (also referred to as a polyvalent hydroxy compound (4)) represented by the following general formula (4) and an aralkyl grouping agent such as styrene. Can be obtained. Since StPNE can be easily epoxidized using a glycidylating agent such as epichlorohydrin, StPN will be described.

StPN is obtained by reacting the polyvalent hydroxy compound (4) with an aralkylating agent. When styrene is used as the aralkylating agent, StPN substituted with R ₂ in which R ₃ and R ₄ in formula (1) are H and R ₅ is methyl is obtained. If benzyl halide is used as the aralkylating agent, StPN in which R ₃ , R ₄ , and R ₅ are H can be obtained. Hereinafter, the aralkylating agent is also referred to as styrene. Aralkylation can use a known reaction method using an acid catalyst.

（一般式（３）及び（４）において、Ｒ₁、Ｒ₂、ｎ、及びｐは一般式（１）と同じ意味を有する。）

(In General Formulas (3) and (4), R ₁ , R ₂ , n, and p have the same meaning as in General Formula (1).)

  In the styrene-added polyvalent hydroxy resin (StPN) represented by the general formula (3), first, a hydroxyl equivalent is arbitrarily adjusted by adding styrenes to the basic structure of the polyvalent hydroxy compound (4). be able to. Here, addition of styrenes means substitution of hydrogen of the benzene ring of the polyvalent hydroxy compound (4) and a substituent represented by the formula (a) (in the case of styrene, α-methylbenzyl group). Say. Addition of styrenes rich in aromaticity is effective in improving moisture resistance, and low water absorption can reduce the occurrence of cracks due to rapid water expansion during solder reflow.

  StPN is obtained by addition reaction of the polyvalent hydroxy compound (4) represented by the general formula (4) and styrenes. At this time, as a ratio of the polyhydroxy compound (4) and the styrenes, considering the balance between the elastic modulus and curability of the obtained cured product, the styrenes with respect to 1 mol of the phenol ring in the polyhydroxy compound. Is preferably in the range of 0.1 to 2.5 mol, more preferably in the range of 0.1 to 1.0 mol, and still more preferably in the range of 0.3 to 0.8 mol. When the amount is less than this range, the properties of the starting polyvalent hydroxy compound are not improved. When the amount is more than this range, the functional group density tends to be too low and the curability tends to decrease. This molar ratio is related to p in the general formula (1).

In general formulas (3), (4) and general formula (1), common symbols have the same meaning. R ₂ represents a group represented by the above formula (a). p shows the number of 0.1-2.5, and this means the average number (number average) of the aralkyl group substituted by one phenol ring (or benzene ring) in a formula. p is preferably in the order of 0.1 to 2, 0.1 to 1.0, 0.3 to 1, and 0.3 to 0.8. In addition, since at most 4 aralkyl groups can be substituted on the phenol ring (or benzene ring) at both ends, and at most 3 aralkyl groups can be substituted on the intermediate phenol ring (or benzene ring), n is 1. In some cases, up to 8 aralkyl groups can be substituted.
From another point of view, the StPNE used in the present invention preferably has a substitution number (number average) of aralkyl groups per molecule of 1 or more, more preferably 2 or more, still more preferably 2.6 to 4.

In formula (a), R ₃ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, preferably hydrogen or an alkyl group having 1 to 3 carbon atoms, more preferably hydrogen or a methyl group. This R ₃ is determined by the styrenes used as reaction raw materials. R ₄ and R ₅ represent hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, preferably hydrogen or an alkyl group having 1 to 6 carbon atoms, more preferably hydrogen or a methyl group. R _{4 to} R ₅ may be the same or different, but when one is a hydrocarbon group, the other is preferably hydrogen.

  In the general formula (1), n represents a number of 1 to 20, preferably 1.5 to 5.0 as an average (number average).

  Reactions in which the StPN is used as the epoxy resin StPNE are known, and these known reactions can be employed. Preference is given to a method in which an excess of epichlorohydrin is used and the reaction is carried out in the presence of an alkali catalyst. For example, a method for producing a novolac type epoxy resin from a novolac type phenol resin can be employed.

  In the resin composition of the present invention, the epoxy resin represented by the above general formula (1) is used as an essential epoxy resin as an epoxy resin component, but other epoxy resins are used in combination as long as the object of the present invention is not impaired. You can also.

  Examples of such other epoxy resins include bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl. Epoxidized products of divalent phenols such as resorcin, naphthalenediols, tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolac, o-cresol Epoxides of trivalent or higher phenols such as novolak, epoxidized products of cocondensation resins obtained from dicyclopentadiene and phenols, epoxidized products of cocondensation resins obtained from cresols, formaldehyde and alkoxy-substituted naphthalenes, phenols And paraxilile Epoxy product of phenol aralkyl resin obtained from dichloride, etc., Epoxy product of biphenyl aralkyl type phenol resin obtained from phenols and bischloromethylbiphenyl, etc., Epoxy of naphthol aralkyl resins synthesized from naphthols and paraxylylene dichloride, etc. And the like. These epoxy resins may be used alone or in combination of two or more. Although these compounding quantities should just be a range which does not impair the objective of this invention, it is less than 50 weight% with respect to the sum total of StPNE and the said resin. Preferably, StPNE is used in an amount of 60% by weight or more, more preferably 75% by weight or more based on the total epoxy resin.

Next, (C) a photopolymerizable monomer or oligomer (hereinafter also referred to as “component (C)”) constituting the photosensitive resin composition of the present invention will be described. As the component (C), a monomer or oligomer copolymerizable with the component (A) is used, but the component corresponding to the component (A) is not the component (C).
Examples of such monomers or oligomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and trimethylolpropane tri (meth). Acrylate, tetramethylolmethane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, N, N'-methylenebis (meth) acrylate, diethylaminoethyl (meth) acrylate, tris (hydroxyethyl) Acryloyl) isocyanurate and the like.

  Next, (D) a photopolymerization initiator or a sensitizer (hereinafter referred to as “component (D)”) constituting the photosensitive resin composition of the present invention will be described. Examples of the component (D) include acetophenones such as acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, and p-tert-butyltrichloroacetophenone. Benzophenone, 2-chlorobenzophenone, p, p'-dichlorobenzophenone, p, p'-bisdimethylaminobenzophenone (also called Michler's ketone), p, p'-bisdiethylaminobenzophenone, 3,3 ', 4,4'-tetra Benzophenones such as (tert-butylperoxycarbonyl) benzophenone, benzoin such as benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin-n-butyl ether Ethers, benzyldimethyl ketal, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, etc. Sulfur compounds, 2-ethylanthraquinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone and other anthraquinones, azobisisobutyronitrile, benzoyl peroxide, di Organic peroxides such as -tert-butyl peroxide and cumene peroxide, 2,4,5-triarylimidazole dimer, riboflavin tetrabutyrate, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercapto Benzothiazo Thiol compounds such as 2,4,6-Bok squirrel (trichloromethyl) -S- Bok triazine, 2,2,2-bromo ethanol, organic halogen compounds such as tribromomethylphenyl sulfone.

  These compounds can also be used in combination. In addition, a compound that does not act as a photopolymerization initiator itself, but that can increase the ability of the photopolymerization initiator by using it in combination with the above-mentioned compound can also be added. Examples of such compounds include tertiary amines such as triethanolamine which are effective when used in combination with benzophenone.

  The resin composition of the present invention contains the above component (A), component (B), component (C), and component (D) as essential components. The ratio is 10 to 200 parts by weight of the component (B), 5 to 50 parts by weight of the component (C), and 1 to 30 parts by weight of the component (D) with respect to 100 parts by weight of the component (A).

  A carboxyl group capable of alkali development, when present as a carboxyl group after development, causes deterioration of physical properties such as moisture resistance and electrical insulation, and thus it is desirable to react with the epoxy resin of component (B). The suitable range of the amount of component (B) used is usually preferably such a ratio that the epoxy group of the epoxy resin is 0.2 to 3.0 equivalents per equivalent of carboxyl groups in the epoxy acrylate resin. Among these, a ratio of 1.0 to 2.0 equivalents is preferable from the viewpoint of excellent electrical characteristics when a printed wiring board is used.

  When the blending ratio of the component (B) is too small, the heat resistance is insufficient, and when used as a solder resist or an insulating film, not only peeling occurs on the copper circuit during the soldering process, but also electroless gold plating resistance and coating It is not preferable because the film hardness is insufficient. On the other hand, when the amount is too large, the alkali developability after exposure deteriorates, which is not preferable. In addition, when the blending ratio of the component (C) is too small, the photocuring speed is lowered and the crosslinking density is also lowered, so that the film-forming property and the film properties are not sufficient. Since it is too high and thermal shrinkage occurs during the soldering process, peeling of the film occurs and at the same time the surface drying property is lowered, it is not preferable. Furthermore, when the proportion of the component (D) is too small, sufficient crosslinking by light irradiation cannot be performed. On the other hand, when the amount is too large, it becomes difficult for light to reach the substrate. This is not preferable because of the fact that the confidentiality of the product deteriorates.

  In addition to the components (A) to (D), the resin composition of the present invention includes an epoxy curing accelerator, a polymerization inhibitor, a filler, a paint, a pigment, a plasticizer, a leveling agent, an adhesion improver, and an antifoaming agent. Further, additives such as flame retardants, compounding agents such as organic solvents, and additives can be blended. The types and amounts of such compounding agents and additives are appropriately selected within a range that does not impair the properties of the resin composition of the present invention.

  Examples of the epoxy curing accelerator include amine compounds, imidazole compounds, carboxylic acids, phenols, quaternary ammonium salts, or methylol group-containing compounds, which are used in combination with a small amount to post-heat the coating film. Thus, various properties such as heat resistance, solvent resistance, acid resistance, plating resistance, adhesion, electrical properties and hardness of the resulting resist film can be improved, and it is particularly suitable as a solder resist.

  Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, phenothiazine and the like. Examples of the filler include alumina, clay, talc, fine powder silica, barium sulfate, barium carbonate, magnesium oxide, and titanium oxide.

  Examples of the dyes and pigments include phthalocyanine green, phthalocyanine blue, phthalocyanine yellow, benzidine yellow, permanentole R, brilliant carmine 6B, and the like. As a plasticizer, dibutyl phthalate. Examples include dioctyl phthalate and tricresyl.

  Examples of the antifoaming agent and leveling agent include silicon-based, fluorine-based, and acrylic compounds. Examples of the flame retardant include inorganic flame retardants such as aluminum hydroxide and zinc borate, and halogenated phosphates such as tris- (β-chloroethyl) -phosphate and pentachlorophenol methacrylate. Flame retardants.

  The photosensitive resin composition of the present invention can be suitably used as a solder resist of a printed wiring board or an insulating film of a build-up substrate, and can sufficiently withstand electroless gold plating, and forms a solder resist film Thereafter, electroless gold plating can be performed.

  Examples of the developer suitable for alkali development of the photosensitive resin composition of the present invention include an aqueous solution of an alkali metal or alkaline earth metal carbonate, an aqueous solution of an alkali metal hydroxide, and the like. In particular, a fine image can be precisely developed even when using a weakly alkaline solution of 1 to 3% by weight of a carbonate such as sodium carbonate, potassium carbonate or lithium carbonate. The alkali development of the resin composition of the present invention can be carried out at a temperature of 10 to 50 ° C., preferably 20 to 40 ° C., using a commercially available developing machine or ultrasonic cleaner.

  The photosensitive resin composition of the present invention is cured not only by light but also by heat. As a light source suitable for curing by light, an ultra-high pressure water root lamp, a high pressure water root lamp, a metal halide lamp, etc. The light oscillated from the lamp of the above and the like.

  The photosensitive resin composition of the present invention can be suitably used as a solder resist for a printed wiring board as described above, but when used as a solder resist, first, the surface of the printed wiring board of the present invention is used. The resin composition is applied as a solution, or a film is formed by a method such as attaching a dry film comprising the resin composition of the present invention to the surface of a printed wiring board, and then the film thus obtained A negative film is applied on the surface, irradiated with actinic rays to cure the exposed portion, and further, the unexposed portion is eluted with a weak alkaline aqueous solution.

  In order to improve the corrosion resistance after alkali development, it is desirable to apply a curing treatment by heating. In the resin composition of the present invention, by performing heat treatment, not only the durability against strong alkaline water is remarkably improved, but also required for solder resists such as adhesion to metals such as copper, heat durability, surface hardness, etc. Improved properties. Examples of the heating temperature and the heating time under the heat curing conditions include 80 to 200 ° C. and 10 minutes to 2 hours, respectively.

  Solvents suitable for preparing the solution of the resin composition of the present invention include, for example, ketones such as methyl ethyl ketone and methyl isobutyl ketone, cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve acetate, and carbitol acetate. Examples include carbitols.

  As a method for applying the solution of the resin composition of the present invention to a printed wiring board, any method such as a method using a roller coater or a spinner applicator can be adopted in addition to a solution dipping method and a spray method. . By applying the resin composition solution to a thickness of, for example, 20 to 30 μm by these methods and then removing the solvent, a film is formed.

  A dry film made of the resin composition of the present invention is prepared by applying a solution of the above resin composition to a flexible support film such as a polyethylene terephthalate film and drying it. The dry film may be covered with a polyethylene film for protection.

  Hereinafter, the present invention will be described more specifically with reference to examples.

(Synthesis of polyvalent hydroxy resin)
Synthesis example 1
105 g of phenol novolak (manufactured by Showa Denko; BRG-555, hydroxyl group equivalent 105 g / eq., Softening point 67 ° C., melt viscosity 0.050 Pa · s at 150 ° C.) as a polyvalent hydroxy compound component in a 1 L 4-neck flask Then, 0.055 g (300 ppm) of p-toluenesulfonic acid was charged as an acid catalyst, and the temperature was raised to 120 ° C. Next, with stirring at 120 ° C., 73 g (0.7 mol) of styrene was dropped over 3 hours to be reacted. Furthermore, after reacting at 120 ° C. for 1 hour, 170 g of a styrene-modified polyvalent hydroxy resin was obtained (StPN). Its hydroxyl equivalent is 178 g / eq. The softening point was 78 ° C., and the melt viscosity at 150 ° C. was 0.13 Pa · s.

Synthesis example 2
(Synthesis of epoxy resin)
In a four-necked separable flask, 150 g of StPN obtained in Synthesis Example 1, 468 g of epichlorohydrin, and 70 g of diethylene glycol dimethyl ether were stirred and dissolved. After uniformly dissolving, maintaining at 65 ° C. under a reduced pressure of 130 mmHg, 70.3 g of 48% aqueous sodium hydroxide solution was added dropwise over 4 hours, and the water and epichlorohydrin distilled off during the addition were separated in a separation tank, and epichlorohydrin was The mixture was returned to the reaction vessel, and water was removed from the system to react. After completion of the reaction, the salt produced by filtration was removed, and after further washing with water, epichlorohydrin was distilled off to obtain 185 g of epoxy resin (epoxy resin A). The epoxy equivalent of the obtained resin was 246 g / eq. The softening point was 56 ° C. and the melt viscosity at 150 ° C. was 0.10 Pa · s.

Synthesis example 3
(Synthesis of epoxy acrylate resin)
160 g of the epoxy resin obtained in Synthesis Example 2 is dissolved in 40 g of carbitol acetate, and 46.9 g of acrylic acid, 3.2 g of triphenylphosphine and 0.1 g of hydroquinone are added, and air is blown at 110 ° C. for 8 hours. An epoxy acrylate resin was obtained by reaction. The epoxy equivalent of the epoxy acrylate resin after the reaction was 10875 g / eq. The viscosity of the solution was 52.5 Pa · s (25 ° C.). Moreover, when titration was performed with a 0.1 N KOH / MeOH solution, the acid value was 3.2 (mg KOH / g).

Synthesis example 4
(Synthesis of acid anhydride adduct of epoxy acrylate)
Tetrahydrophthalic anhydride (74.2 g) and carbitol acetate (146.6 g) were added to the epoxy acrylate resin obtained in Synthesis Example 3 and reacted at 110 ° C. for 1.5 hours to obtain an acid anhydride adduct of epoxy acrylate (acid). Anhydride adduct A). The epoxy equivalent of the acid anhydride adduct of epoxy acrylate after the reaction was 19022 g / eq. The viscosity of the resin solution was 3.5 Pa · s (25 ° C.). Moreover, when titration was performed with a 0.1 N KOH / MeOH solution, the acid value was 55.2 (mg KOH / g).

Synthesis example 5
(Synthesis of epoxy acrylate resin)
160 g of phenol novolac epoxy resin (YDPN-638 epoxy equivalent of 177 g / eq. Manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) is dissolved in 40 g of carbitol acetate, and further 65.1 g of acrylic acid, 3.2 g of triphenylphosphine, and 0.1 g of hydroquinone are added. In addition, an epoxy acrylate resin was obtained by reacting at 110 ° C. for 8 hours while blowing air. The epoxy equivalent of the epoxy acrylate resin after the reaction is 12000 g / eq. The viscosity of the solution was 58.0 Pa · s (25 ° C.). Moreover, when titration was performed with a 0.1 N KOH / MeOH solution, the acid value was 2.5 (mg KOH / g).

Synthesis Example 6
(Synthesis of acid anhydride adduct of epoxy acrylate)
To the epoxy acrylate resin obtained in Synthesis Example 5, 74.2 g of tetrahydrophthalic anhydride and 146.6 g of carbitol acetate were added and reacted at 110 ° C. for 1.5 hours to obtain an acid anhydride adduct of epoxy acrylate (acid). Anhydride adduct B). The epoxy equivalent of the acid anhydride adduct of epoxy acrylate after the reaction was 20990 g / eq. The viscosity of the resin solution was 4.0 Pa · s (25 ° C.). Moreover, when titration was performed with a 0.1 N KOH / MeOH solution, the acid value was 55.0 (mg KOH / g).

Examples 1-2 and Comparative Examples 1-2
The acid anhydride adducts A and B obtained in Synthesis Examples 4 and 6 were used as the acid anhydride adduct component of epoxy acrylate, and the epoxy resin A obtained in Synthesis Example 2 and the phenol novolac type were used as the epoxy resin component. Epoxy resin (epoxy resin B; YDPN-638 epoxy equivalent of 177 g / eq. Manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) was used. Dipentaerythritol hexaacrylate (DPHA: manufactured by Daicel Cytec) as the acrylate component, Irgacure 907 (manufactured by BASF) as the photopolymerization initiator, and spherical fused silica FB-60 (manufactured by Denki Kagaku Kogyo Co., Ltd.) as the silica component It was used.

  Each said component was mix | blended in the ratio (weight part) shown in Table 1, the roll mill kneading was performed, and the photosensitive resin composition of each Example 1-2 and Comparative Examples 1-2 was prepared. About the obtained photosensitive resin composition of each Examples 1-2 and Comparative Examples 1-2, the performance evaluation was performed as follows.

About the drying property of a coating film, and the developability with respect to alkaline aqueous solution, apply | coat the photosensitive resin composition with a thickness of 20-30 micrometers on a copper clad laminated board, and dry for 30 minutes at 70 degreeC using a matured air dryer. The obtained coating film was evaluated. In addition, with respect to adhesion to the substrate, solder heat resistance, hardness, chemical resistance and solvent resistance, a high pressure mercury lamp was used, and after exposure for 20 seconds to UV light having a wavelength of 365 nm and an illuminance of 25 mW / cm ² , 1% by weight The film was developed at 25 ° C. for 60 seconds using an aqueous sodium carbonate solution and then heated at 150 ° C. for 30 minutes to evaluate the coating film as a solder resist after complete curing. The results are shown in Table 1.

(1) Gel permeation chromatography (GPC) measurement Tosoh Corporation TSKgelG4000HXL, TSKgelG3000HXL, TSKgelG2000HXL were used in series, and the column temperature was 40 ° C. Tetrahydrofuran was used as the eluent, the flow rate was 1 ml / min, and an RI (differential refractometer) detector was used as the detector. 0.1 g of sample was dissolved in 10 ml of THF. The weight average molecular weight (Mw) and the number average molecular weight (Mn) were determined by a calibration curve using standard polystyrene.

(2) Softening point It measured by the ring and ball method according to JIS-K-2207 using the automatic softening point apparatus (Myohosha make, ASP-M4SP).

(3) Viscosity Viscosity was measured using an E-type rotational viscometer manufactured by BROOKFIELD.

(4) Measurement of epoxy equivalent Using a potentiometric titrator, methyl ethyl ketone was used as a solvent, a brominated tetraethylammonium acetic acid solution was added, and measurement was performed using a 0.1 mol / L perchloric acid-acetic acid solution.

(5) Measurement of acid value Using a potentiometric titrator, dioxane was used as a solvent, and measurement was performed using a 0.1 N KOH methanol solution.

In addition, the evaluation criteria of each physical property are as follows.
(1) Drying property of coating film The drying property of the coating film was evaluated according to JIS K-5400. The evaluation was performed in three stages: ◎: no tack was found, ◯: a slight tack was found, and x: a marked tack was found.

(2) Developability Using a 1% by weight aqueous sodium carbonate solution, development was carried out at 25 ° C. for 60 seconds, and the resin remaining after being magnified 40 times was visually evaluated. The evaluation was performed in three stages: ◎: no resist left on the copper surface, ◯: only a little resist left on the copper surface, and x: a resist clearly left on the copper surface.

(3) Coating film hardness After the exposure and development, the hardness of the coating film heated at 145 ° C for 50 minutes was evaluated according to the test method of JIS K-5400.

(4) Adhesive exposure, developed, and then cross-cut into a coating film heated at 145 ° C. for 50 minutes so as to make at least 100 gobangs, and then subjected to a peeling test using an adhesive tape. The state of eye peeling was visually evaluated. Evaluation: ◎: no peeling was observed at all measurement points, ○: peeling was observed at 1 to 20 measurement points out of 100 measurement points, x: 21 or more out of 100 measurement points This was performed in three stages, i.e., where peeling was observed at the measurement point.

(5) Solder heat resistance After exposure and development, the coating film heated at 145 ° C. for 50 minutes is immersed in a solder bath at 260 ° C. for 20 seconds in accordance with JIS D-0202. evaluated. The evaluation was made in three stages: ◎: no abnormality in the appearance of the coating film, ○: a slight bulge in the appearance of the coating film, ×: swelled in the appearance of the coating film, melting, and peeling. went.

(6) Chemical resistance After exposure and development, the coating film heated at 145 ° C. for 50 minutes was immersed in the following chemicals at 25 ° C. for 1 hour, respectively, and the appearance and adhesion after immersion were evaluated.
Acid resistance; 10% by weight hydrochloric acid aqueous solution alkali resistance; 10% by weight caustic soda aqueous solution solvent resistance; trichloroethane, isopropanol alcohol Evaluation is no abnormality in the acid resistance, alkali resistance, and solvent resistance tests. Slightly swollen, Δ, and dissolved or swollen, x.

Claims (3)

(A) an acid anhydride adduct of epoxy acrylate,
(B) an epoxy resin represented by the following general formula (1),

(Here, G represents a glycidyl group, R ₁ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, R ₂ represents an aralkyl group represented by the following formula (a), and n represents 1 to 20) In addition, p represents a number of 0.1 to 2.5.)

(Here, R _{3 to} R ₅ represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.)
(C) A photopolymerizable monomer or oligomer, and (D) a photopolymerization initiator or a sensitizer, and an alkali development type photosensitive resin composition.   The alkali-developable photosensitive resin composition according to claim 1, wherein the aralkyl group is an aralkyl group derived from styrene.   A cured product obtained by curing the alkali-developable photosensitive resin composition according to claim 1.