JP6783600B2 - Curable resin composition, dry film, printed wiring board, and method for manufacturing printed wiring board - Google Patents

Description

The present invention relates to a curable resin composition, a dry film, a printed wiring board, and a method for manufacturing a printed wiring board.

A curable resin composition is used as a material such as a solder resist used for forming a printed wiring board (for example, Patent Document 1). In recent years, due to the rapid progress of semiconductor components, electronic devices tend to be lighter, thinner, shorter, smaller, have higher performance, and have more functions. Following this tendency, miniaturization and multi-pinning of semiconductor packages have been put into practical use. Specifically, BGA (ball grid array), CSP (chip scale package), etc., instead of IC packages called QFP (quad flat pack package), SOP (small outline package), etc. An IC package called is used. In recent years, FC-BGA (flip chip ball grid array) has also been put into practical use as an IC package with a higher density. In a printed wiring board (also referred to as a package substrate) used for such an IC package, the SRO (Solder Rest Opening) pitch is narrow and formed close to each other, so that short circuits and crosstalk noise occur between the SROs. There is a high risk of crosstalk. Further, the solder resist formed between the SROs is thin and thin, so that cracks are likely to occur. Therefore, a high degree of reliability is required for a permanent coating such as a solder resist used for a package substrate.

In order to improve reliability, a cured product such as a solder resist is required to have heat resistance and strength. Further, from the viewpoint of suppressing cracks and the like, it is also required to impart flexibility such as elongation.

Japanese Unexamined Patent Publication No. 2005-31233

The heat resistance can be improved by increasing the glass transition temperature (Tg) of the cured product. In order to obtain a cured product having excellent glass transition temperature and strength, it is conceivable to increase the crosslink density. However, if the crosslink density of the cured product is increased, the flexibility is lowered, so that it is difficult to obtain a good balance between the glass transition temperature, the strength and the flexibility.

Therefore, an object of the present invention is a curable resin composition capable of obtaining a cured product having a high glass transition temperature and excellent strength and flexibility, a dry film having a resin layer obtained from the composition, and a cured product thereof. , A printed wiring board having the cured product, and a method for manufacturing a printed wiring board using the composition.

As a result of diligent studies in view of the above, the present inventors have found that the above problems can be solved by using a curable resin composition containing two specific types of carboxyl group-containing resins, and have completed the present invention. It was.

That is, the curable resin composition of the present invention comprises (A) a reaction product (A1) of an epoxy resin, a compound containing a phenolic hydroxyl group and an alcoholic hydroxyl group, and an unsaturated carboxylic acid, and a polybasic acid anhydride. Photosensitive carboxyl group-containing resin, which is a reaction product, (B) Reaction product of epoxy resin and unsaturated carboxylic acid (B1), reaction product of polybasic acid anhydride (B2), oxylan ring and ethylene. It is characterized by containing a photosensitive carboxyl group-containing resin which is a reaction product with a compound having a sex unsaturated group, (C) a photopolymerization initiator, and (D) an epoxy resin.

The curable resin composition of the present invention preferably has a compounding ratio (mass ratio) of the (A) carboxyl group-containing resin and the (B) carboxyl group-containing resin of 3: 7 to 7: 3.

The dry film of the present invention is characterized by having a resin layer obtained by applying the curable resin composition on the film and drying it.

The cured product of the present invention is characterized by being obtained by curing the curable resin composition or the resin layer of the dry film.

The printed wiring board of the present invention is characterized by including the cured product.

In the method for producing a printed wiring board of the present invention, the curable resin composition is applied and dried on a base material, or the resin layer of the dry film is laminated to form a resin layer on the base material. A photo-curing step of selectively irradiating the resin layer on the substrate with light to cure the resin, a developing step of removing an unirradiated portion by development after the photo-curing step to obtain a pattern layer, and irradiating the pattern layer with light. It is characterized by including a light irradiation step and a step of heating the light-irradiated pattern layer.

According to the present invention, a curable resin composition capable of obtaining a cured product having a high glass transition temperature and excellent strength and flexibility, a dry film having a resin layer obtained from the composition, a cured product thereof, and the like. It is possible to provide a printed wiring board having a cured product and a method for producing a printed wiring board using the composition.

The curable resin composition of the present invention is a reaction product of (A) an epoxy resin, a reaction product (A1) of a compound containing a phenolic hydroxyl group and an alcoholic hydroxyl group, and an unsaturated carboxylic acid, and a polybasic acid anhydride. Photosensitive carboxyl group-containing resin (hereinafter, also referred to as "(A) carboxyl group-containing resin"), (B) reaction product of epoxy resin and unsaturated carboxylic acid (B1), and polybasic acid anhydride. A photosensitive carboxyl group-containing resin (hereinafter, also referred to as “(B) carboxyl group-containing resin”), which is a reaction product of the reaction product (B2) of (B2) and a compound having an oxylane ring and an ethylenically unsaturated group. It contains (C) a photopolymerization initiator and (D) an epoxy resin. When obtaining a cured product of the curable resin composition of the present invention, it is preferable that after developing to form a pattern layer, the pattern layer is irradiated with light and then heated to be thermoset. By performing the light irradiation step after forming such a pattern layer and before heating, a patterned cured product having a high glass transition temperature and excellent strength and flexibility can be easily obtained. Although the detailed mechanism is not clear, by using (A) a carboxyl group-containing resin and (B) a carboxyl group-containing resin in combination, a photocrosslinking point derived from the reaction of an ethylenically unsaturated group and a carboxyl group and an epoxy group It is considered that this is because the distance balance with the thermal cross-linking point derived from the reaction of

Further, in the technical field of the present invention, it is known that an elastomer is blended as a means for imparting flexibility to a cured product, but when the elastomer is blended, there is a problem that the resolution is lowered. Since the cured product obtained from the curable resin composition of the present invention has excellent flexibility without blending an elastomer, both resolution and flexibility can be achieved at the same time.

The compounding ratio (mass ratio) of the (A) carboxyl group-containing resin and the (B) carboxyl group-containing resin is preferably 3: 7 to 7: 3, and more preferably 4: 6 to 6: 4. preferable.

((A) Photosensitive carboxyl group-containing resin which is a reaction product of (A1) an epoxy resin, a compound containing a phenolic hydroxyl group and an alcoholic hydroxyl group, and an unsaturated carboxylic acid, and a polybasic acid anhydride. )
It is considered that the structure derived from the compound containing the phenolic hydroxyl group and the alcoholic hydroxyl group of the (A) carboxyl group-containing resin particularly contributes to the flexibility.

As the epoxy resin, a known and commonly used compound having one or more epoxy groups can be used, and among them, a compound having two or more epoxy groups is preferable. For example, monoepoxy compounds such as monoepoxy compounds such as butyl glycidyl ether, phenylglycidyl ether, and glycidyl (meth) acrylate, bisphenol A type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, Cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, trisphenol methane type epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, glycidyl ester resin, glycidyl amine resin, trimethylolpropanpolyglycidyl ether, phenyl -1,3-diglycidyl ether, biphenyl-4,4'-diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol or propylene glycol diglycidyl ether, sorbitol polyglycidyl ether, tris (2,3) Examples thereof include compounds having two or more epoxy groups in one molecule, such as −epoxypropyl) isocyanurate and triglycidyltris (2-hydroxyethyl) isocyanurate. One type of the epoxy resin may be used alone, or two or more types may be used in combination.

Specific examples of the compound having two or more epoxy groups include jER828, jER834, jER1001, jER1004 manufactured by Mitsubishi Chemical Corporation, Epicron 840, Epicron 850, Epicron 1050, Epicron 2055 manufactured by DIC Corporation, and Nippon Steel & Sumikin Chemical Co., Ltd. Epoxy YD-011, YD-013, YD-127, YD-128, Dow Chemical Japan Co., Ltd. E. R. 317, D.I. E. R. 331, D. E. R. 661, D.I. E. R. 664, Sumitomo Chemical Co., Ltd. Sumi-Epoxy ESA-011, ESA-014, ELA-115, ELA-128, Asahi Kasei E-Materials Co., Ltd. E. R. 330, A. E. R. 331, A. E. R. 661, A. E. R. Bisphenol A type epoxy resin such as 664; jERYL903 manufactured by Mitsubishi Chemical Corporation, Epicron 152 and Epicron 165 manufactured by DIC, Epototo YDB-400 and YDB-500 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., D.D. E. R. 542, Sumitomo Chemical's Sumi-Epoxy ESB-400, ESB-700, Asahi Kasei E-Materials' A.M. E. R. 711, A. E. R. Brominated epoxy resin such as 714; jER152, jER154 manufactured by Mitsubishi Chemical Corporation, D.D. E. N. 431, D.I. E. N. 438, Epicron N-730, Epicron N-770, Epicron N-865 manufactured by DIC, Epototo YDCN-701, YDCN-704 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., EPPN-201, EOCN-1025 manufactured by Nippon Kayaku Co., Ltd. EOCN-1020, EOCN-104S, RE-306, NC-3000, Sumitomo Chemical's Sumi-Epoxy ESCN-195X, ESCN-220, Asahi Kasei E-Materials' A.M. E. R. ECN-235, ECN-299, YDCN-700-2, YDCN-700-3, YDCN-700-5, YDCN-700-7, YDCN-700-10, YDCN-704, YDCN- manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Novorak type epoxy resins such as 704A and DIC's Epicron N-680, N-690, N-695; DIC's Epicron 830, Mitsubishi Chemical's jER807, Nippon Steel & Sumikin Chemical's Epototo YDF-170, YDF Bisphenol F type epoxy resin such as -175, YDF-2004; Hydrogenated bisphenol A type epoxy resin such as Epototo ST-2004, ST-2007, ST-3000 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd .; jER604, Nippon Steel Co., Ltd. manufactured by Mitsubishi Chemical Co., Ltd. Epototo YH-434 manufactured by Sumikin Chemical Co., Ltd .; Glycidylamine type epoxy resin such as Sumi-epoxy ELM-120 manufactured by Sumitomo Chemical Co., Ltd .; Hydant-in type epoxy resin; Alicyclic epoxy resin such as Celoxide 2021 manufactured by Daicel Co. YL-933 manufactured by Dow Chemical Japan Co., Ltd. E. N. , EPPN-501, EPPN-502 and the like trihydroxyphenylmethane type epoxy resin; Mitsubishi Chemical Co., Ltd. YL-6056, YX-4000, YL-6121 and the like bixilenol type or biphenol type epoxy resin or a mixture thereof; Bisphenol S type epoxy resin such as EBPS-200 manufactured by Kayakusha, EPX-30 manufactured by ADEKA, EXA-1514 manufactured by DIC; Bisphenol A novolac type epoxy resin such as jER157S manufactured by Mitsubishi Chemical Co., Ltd .; Tetraphenylol ethane type epoxy resin such as jERYL-931; heterocyclic epoxy resin such as TEPIC manufactured by Nissan Chemical Industries; diglycidyl phthalate resin such as Blemmer DGT manufactured by Nikko Co., Ltd .; ZX-1063 manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd. Tetraglycidyl xylenoyl ethane resin; Naphthalene group-containing epoxy resin such as ESN-190, ESN-360, DIC HP-4032, EXA-4750, EXA-4700 manufactured by Nippon Steel & Sumitomo Metal Corporation; HP-7200 manufactured by DIC , HP-7200H and other epoxy resins having a dicyclopentadiene skeleton; glycidyl methacrylate copolymerized epoxy resins such as CP-50S and CP-50M manufactured by Nichiyu Co., Ltd .; and cyclohexyl maleimide and glycidyl methacrylate copolymerized epoxy resins; CTBN-modified epoxy resins (for example, YR-102, YR-450 manufactured by Nippon Steel & Sumitomo Metal Corporation); trisphenol methane type epoxy resins and the like can be mentioned, but are not limited thereto. Among these, a bixylenol type epoxy resin, a biphenol type epoxy resin, a novolac type epoxy resin, and a bisphenol A novolak type epoxy resin are preferable.

（式中、ｘは、０〜５までの整数であり、ベンゼン環の水素と置換する置換基Ｒ^１の数を表し、Ｒ^１は、ｘが１のとき、炭素数１〜４の飽和または不飽和アルキル基、フェニル基またはシクロヘキシル基の中から選ばれる一つの置換基を表し、ｘが２以上のとき、前記置換基の中から重複を許してｘ個選ばれる同一または異なる複数の置換基を表す。ｙは１〜５の整数であり、ベンゼン環の水素と置換する置換基Ｒ^２−ＯＨの数を表し、Ｒ^２は、ｙが１のとき、炭素数１〜２０の直鎖、分岐または環状のアルキレン基または

（ここで、Ｒ^３はエチレン基、プロピレン基、ヒドロキシプロピレン基または

（ｎ＝２または３、ｚ＝１または２）である。）の中から選ばれる一つの置換基を表し、ｙが２以上のとき、前記置換基の中から重複を許してｙ個選ばれる同一または異なる複数の置換基を表す。） The compound containing the phenolic hydroxyl group and the alcoholic hydroxyl group is not particularly limited, but is preferably a compound represented by the following general formula (1). As the compound containing the phenolic hydroxyl group and the alcoholic hydroxyl group, one type may be used alone, or two or more types may be used in combination.

(Wherein, x is an integer from 0 to 5, represents the number of substituents R ^1, which replaces the hydrogen of the benzene ring, R ^1, when x is 1, 1 to 4 carbon atoms, saturated or Represents one substituent selected from an unsaturated alkyl group, a phenyl group or a cyclohexyl group, and when x is 2 or more, the same or different plurality of substituents are selected by allowing duplication from the above substituents. .y representing a is an integer from 1 to 5, represents the number of substituents ^R 2 -OH replacing the hydrogen of the benzene ring, ^{R 2,} when y is 1, a straight-chain having 1 to 20 carbon atoms, Branched or cyclic alkylene group or

(Here, R ³ is an ethylene group, a propylene group, a hydroxypropylene group or

(N = 2 or 3, z = 1 or 2). ), And when y is 2 or more, it represents the same or different plurality of substituents selected from y by allowing duplication. )

The unsaturated carboxylic acid is not particularly limited, and is, for example, acrylic acid, methacrylic acid, crotonic acid, vinylacetic acid, sorbic acid, cinnamic acid; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl. Unsaturated dibasic acid in hydroxyl group-containing acrylates such as (meth) acrylate, trimethylolpropandi (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and caprolactone (meth) acrylate adduct. Examples thereof include those to which an anhydride is added. Here, acrylic acid and methacrylic acid are particularly preferable. The unsaturated carboxylic acid may be used alone or in combination of two or more. In addition, in this specification, (meth) acrylate is a generic term for acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

The reaction of an epoxy resin, a compound containing a phenolic hydroxyl group and an alcoholic hydroxyl group, and an unsaturated carboxylic acid is a method of simultaneously reacting an epoxy resin with a compound containing a phenolic hydroxyl group and an alcoholic hydroxyl group and an unsaturated carboxylic acid. Alternatively, the epoxy resin is first reacted with a compound containing a phenolic hydroxyl group and an alcoholic hydroxyl group, and then an unsaturated carboxylic acid is reacted, or the epoxy resin is reacted with an unsaturated carboxylic acid, and then the phenolic hydroxyl group and the alcoholic hydroxyl group are reacted. There are methods for reacting the containing compounds, and any of them can be adopted. Such a reaction is carried out in the presence or absence of an organic solvent described later, using a polymerization inhibitor such as hydroquinone or oxygen, a tertiary amine such as triethylamine, a quaternary ammonium salt such as triethylbenzylammonium chloride, or 2-ethyl. It can be easily carried out at 80 to 130 ° C. in the coexistence of a reaction catalyst such as an imidazole compound such as -4-methylimidazole and a phosphorus compound such as triphenylphosphine.

The ratio of each component in the reaction is such that the phenolic hydroxyl group of the compound containing the phenolic hydroxyl group and the alcoholic hydroxyl group is 0.2 to 0.6 equivalent with respect to 1 equivalent of the epoxy group of the epoxy resin, and the phenol is phenol. The ratio of the phenolic hydroxyl group of the compound containing the acidic hydroxyl group and the alcoholic hydroxyl group and the carboxyl group of the unsaturated carboxylic acid to a total of 0.8 to 1.3 equivalents is preferable. Increasing the proportion of compounds containing phenolic and alcoholic hydroxyl groups improves hygroscopicity and PCT resistance, increasing resolution and reproducibility of surface and bottom line widths of cured products. It is preferable that the proportion of unsaturated carboxylic acid does not decrease too much, and as a result, the photoreactivity and the development resistance of the surface of the cured film after light irradiation are improved, the decrease in sensitivity is suppressed, and the workability is improved. It is also preferable in terms of surface.

The polybasic acid anhydride is not particularly limited, and for example, methyltetrahydroanhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrohydride, nadicic anhydride, 3,6-endomethylenetetrahydro. Alicyclic dibasic anhydrides such as phthalic anhydride, methylendomethylenetetrahydrohydride, methylbutenyltetrahydrophthalic anhydride, tetrabromophthalic anhydride, chlorendic anhydride; succinic anhydride, maleic anhydride, itaconic anhydride. , Octenyl succinic anhydride, pentadodecenyl succinic anhydride, phthalic anhydride, trimellitic anhydride and other aliphatic or aromatic dibasic acid anhydrides, or biphenyltetracarboxylic acid dianhydride, diphenyl ether tetracarboxylic acid dianhydride, butane. Examples thereof include aliphatic or aromatic tetrabasic acid dianhydrides such as tetracarboxylic acid dianhydride, cyclopentanetetracarboxylic acid dianhydride, pyromellitic anhydride, and benzophenone tetracarboxylic acid dianhydride. Among these, alicyclic dibasic acid anhydride is particularly preferable. The polybasic acid anhydride may be used alone or in combination of two or more.

The polybasic acid anhydride is preferably reacted with the alcoholic hydroxyl group of the reaction product (A1) of the epoxy resin, the compound containing the phenolic hydroxyl group and the alcoholic hydroxyl group, and the unsaturated carboxylic acid. In this reaction, the ratio of the anhydride group to the alcoholic hydroxyl group in the reaction product is preferably 99: 1 to 1:99, and the amount of the polybasic acid anhydride used is preferably 99: 1 to 1:99 (A). ) The addition amount is such that the acid value of the carboxyl group-containing resin is 50 to 120 mgKOH / g. The reaction is usually carried out at 50 to 130 ° C. in the presence or absence of an organic solvent described later and in the presence of a polymerization inhibitor such as hydroquinone or oxygen. At this time, if necessary, a tertiary amine such as triethylamine, a quaternary ammonium salt such as triethylbenzylammonium chloride, an imidazole compound such as 2-ethyl-4-methylimidazole, a phosphorus compound such as triphenylphosphine, etc. are added as catalysts. You may.

（式中、Ｒ^１、Ｒ^２、ｘは、上記一般式（１）と同じであり、ｙ１は０〜４の整数を表す。） The carboxyl group-containing resin (A) preferably has the following structure based on the reaction between the epoxy group of the epoxy resin and the compound containing a phenolic hydroxyl group and an alcoholic hydroxyl group.

(In the formula, R ¹ , R ² , and x are the same as the above general formula (1), and y1 represents an integer of 0 to 4.)

The weight average molecular weight of the carboxyl group-containing resin (A) varies depending on the resin skeleton, but is preferably in the range of 2,000 to 150,000, more preferably 5,000 to 100,000. When the weight average molecular weight is 2,000 or more, the tack-free performance is good, the moisture resistance of the coating film after exposure is good, film loss can be suppressed during development, and resolution deterioration can be suppressed. On the other hand, when the weight average molecular weight is 150,000 or less, the developability is good and the storage stability is also excellent.

((B) Reaction product of epoxy resin and unsaturated carboxylic acid (B1) and reaction product of polybasic acid anhydride (B2), and reaction production of a compound having an oxylane ring and an ethylenically unsaturated group Photosensitive carboxyl group-containing resin)
It is considered that the structure derived from the compound having an oxylane ring and an ethylenically unsaturated group (B) of the carboxyl group-containing resin particularly contributes to the glass transition temperature and strength.

The epoxy resin is not particularly limited, and examples thereof include the same epoxy resins as those mentioned as the component for synthesizing the (A) carboxyl group-containing resin. Among them, phenol novolac type epoxy resin, cresol novolac type epoxy resin and bisphenol A novolac type epoxy resin can be particularly preferably used. The epoxy resin preferably has a softening point of 60 ° C. or higher. One type of the epoxy resin may be used alone, or two or more types may be used in combination.

The unsaturated carboxylic acid is not particularly limited, and examples thereof include the same unsaturated carboxylic acid as the component for synthesizing the (A) carboxyl group-containing resin. Among them, acrylic acid has good reactivity with an epoxy group and has excellent photocurability of the produced resin, so that it can be used particularly preferably. The unsaturated carboxylic acid may be used alone or in combination of two or more. When the unsaturated monocarboxylic acid reacts with the epoxy resin, the oxylan ring is cleaved by the reaction between the epoxy group and the carboxyl group, and an ester bond is formed with the hydroxyl group.

The reaction between the epoxy resin and the unsaturated carboxylic acid can be carried out by heating in a suitable reaction diluent.

As the diluent for the reaction between the epoxy resin and the unsaturated carboxylic acid, a photopolymerizable monomer or an organic solvent can be used. The photopolymerizable monomer that can be used as the reaction diluent is not particularly limited, and examples thereof include the same photopolymerizable monomers as the compounds having an ethylenically unsaturated group described later. The organic solvent that can be used as the diluent is not particularly limited, and examples thereof include the same organic solvents as those described later. One type of reaction diluent may be used alone, or two or more types may be used in combination. The reaction diluent is preferably added so as to be 20 to 50% by mass with respect to the total mass of the reaction system.

In the reaction between the epoxy resin and the unsaturated carboxylic acid, the amount of the epoxy group of the epoxy resin and the amount of the unsaturated carboxylic acid to be reacted are preferably substantially the same amount. By setting the amount to approximately the same amount, it is possible to reduce unintended reactions during the subsequent synthetic reaction, and suppress gelation of the resin and deterioration of the storage stability of the curable resin composition. In addition, unreacted carboxyl groups are reduced, low molecular weight compounds in the resin are reduced, and the characteristics of the cured film are improved. The reaction temperature of the epoxy resin and the unsaturated carboxylic acid is preferably 100 to 120 ° C. When the reaction temperature is 100 ° C. or higher, the reaction rate is good and the reaction does not take a long time. When the reaction temperature is 120 ° C. or lower, thermal polymerization of the unsaturated carboxylic acid is prevented, and gelation is less likely to occur during the reaction.

The reaction product (B1) of the epoxy resin and the unsaturated carboxylic acid is further reacted with the polybasic acid anhydride. The reaction product (B1) of the epoxy resin and the unsaturated carboxylic acid can be subjected to the reaction with the dibasic acid anhydride as it is in the reaction diluent solution without isolation. The polybasic acid anhydride is not particularly limited, and examples thereof include the same polybasic acid anhydrides mentioned as the components for synthesizing the (A) carboxyl group-containing resin. Among them, succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride can be particularly preferably used. In the present invention, one type of polybasic acid anhydride may be used alone, or two or more types may be used in combination. The polybasic acid anhydride reacts with the hydroxyl group generated by the reaction of the epoxy resin and the unsaturated carboxylic acid to generate an ester bond and a free carboxyl group.

The amount of the polybasic acid anhydride to be reacted is preferably 0.4 to 1.0 mol times that of the unsaturated carboxylic acid reacted with the epoxy resin. In the epoxy resin, in addition to generating an equivalent number of hydroxyl groups equal to the number of moles of the reacted unsaturated carboxylic acid, there are hydroxyl groups that the epoxy resin had from the beginning. By reacting a polybasic acid anhydride 0.4 to 1.0 mol times as much as the unsaturated carboxylic acid reacted with the epoxy resin, some of the hydroxyl groups of the resin are left as they are, and the remaining hydroxyl groups are esterified. be able to. When the amount of the polybasic acid anhydride to be reacted is 0.4 mol times or more the amount of the unsaturated carboxylic acid reacted with the epoxy resin, the dilute alkali developability of the curable resin composition becomes good. When the amount of the polybasic acid anhydride to be reacted is 1.0 mol times or less of the unsaturated carboxylic acid reacted with the epoxy resin, the storage stability of the curable resin composition is good.

The polybasic acid anhydride can be added to and reacted with the reaction product (B1) of the epoxy resin and the unsaturated carboxylic acid. When the reaction product (B1) is present as a solution of the reaction diluent, the reaction can proceed satisfactorily by adding a polybasic acid anhydride to this solution, dissolving the reaction product (B1), and heating the solution. The reaction temperature is preferably 70 to 100 ° C. The carboxyl group-containing resin, which is a reaction product (B2) obtained by reacting a reaction product (B1) of an epoxy resin and an unsaturated carboxylic acid with a polybasic acid anhydride, has an acid value of 60 to 170 mgKOH / g. It is preferably 60 to 160 mgKOH / g, and more preferably 60 to 160 mgKOH / g. The acid value of the carboxyl group-containing resin can be easily adjusted by selecting the amount of the polybasic anhydride to be reacted. When the acid value is 60 mgKOH / g or more, the dilute alkali developability of the curable resin composition becomes good. When the acid value is 170 mgKOH / g or less, the storage stability of the curable resin composition is good.

The carboxyl group-containing resin, which is a reaction product (B2) obtained by reacting a reaction product (B1) of an epoxy resin and an unsaturated carboxylic acid with a polybasic acid anhydride, has an ethylenically unsaturated group and a carboxyl group. Has. A compound having an oxylane ring and an ethylenically unsaturated group is reacted with the carboxyl group of the carboxyl group-containing resin. The carboxyl group reacts with the oxylan ring to form an ester bond, whereby the ethylenically unsaturated group is bonded to the main chain of the resin. Since the ethylenically unsaturated group bonded by this reaction is bonded to the outermost part of the (B) carboxyl group-containing resin, the reactivity of the resin during the photopolymerization reaction by light irradiation is stereochemically high. Therefore, this (B) carboxyl group-containing resin has good photocurability.

The reaction ratio of the carboxyl group-containing resin to the compound having an oxylan ring and an ethylenically unsaturated group is such that the compound having an oxylan ring and an ethylenically unsaturated group is 0.05 to 1 equivalent of the carboxyl group of the carboxyl group-containing resin. It is preferably 0.4 mol. When it is 0.05 mol or more, the photocurability of the (B) carboxyl group-containing resin becomes good. When it is 0.4 mol or less, the dilute alkali developability of the curable resin composition and the chemical resistance of the cured film are good. Examples of the compound having an oxylane ring and an ethylenically unsaturated group include glycidyl acrylate, glycidyl methacrylate, pentaerythritol glycidyl ether triacrylate, and a compound represented by the following general formula (3). As the compound having an oxylan ring and an ethylenically unsaturated group, one type may be used alone, or two or more types may be used in combination.

（式中、ｍは０、１または２であり、Ｒ^４は水素又はメチル基であり、Ａは６−オキサビシクロ［３．１．０］ヘキシル基、７−オキサビシクロ［４．１．０］ヘプチル基又は８−オキサビシクロ［５．１．０］オクチル基である。）

(In the formula, m is 0, 1 or 2, R ⁴ is a hydrogen or methyl group, A is a 6-oxabicyclo [3.1.0] hexyl group, 7-oxabicyclo [4.1.0]. ] Heptyl group or 8-oxabicyclo [5.1.0] octyl group.)

When the carboxyl group-containing resin exists as a solution of a reaction diluent, the reaction can be suitably proceeded by adding and dissolving a compound having an oxylan ring and an ethylenically unsaturated group to this solution. In addition, a reaction diluent can be further added in order to effectively perform stirring during the reaction. The reaction temperature is preferably 80 to 120 ° C.

The weight average molecular weight of the carboxyl group-containing resin (B) varies depending on the resin skeleton, but is preferably in the range of 2,000 to 150,000, more preferably 5,000 to 100,000. When the weight average molecular weight is 2,000 or more, the tack-free performance is good, the moisture resistance of the coating film after exposure is good, film loss can be suppressed during development, and resolution deterioration can be suppressed. On the other hand, when the weight average molecular weight is 150,000 or less, the developability is good and the storage stability is also excellent.

The curable resin composition of the present invention may contain an alkali-soluble resin such as another carboxyl group-containing resin as long as the curing of the present invention is not impaired.

((C) Photopolymerization Initiator)
As the photopolymerization initiator (C), any known photopolymerization initiator or photoradical generator can be used.

Examples of the photopolymerization initiator (C) include bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, and bis-. (2,6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphine oxide, Bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,4) , 6-trimethylbenzoyl) -bisacylphosphine oxides such as phenylphosphine oxide; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyl Monoacyls such as phenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (IRGACURE TPO manufactured by BASF Japan) Phosphine oxides; 1-hydroxy-cyclohexylphenylketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1- {4- [4- (2-Hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, etc. Hydroxyacetophenones; Benzoyls such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, benzoin n-butyl ether; benzoin alkyl ethers; benzophenone, p-methylbenzophenone, Michelers ketone, Benzoyls such as methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2 -Diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2 -Dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl) -1- [4- (4-morpholinyl) phenyl]- Acetphenones such as 1-butanone, N, N-dimethylaminoacetophenone; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4 -Thioxanthons such as diisopropylthioxanthone; anthracinones such as anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylantraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone; acetophenone Ketals such as dimethyl ketal, benzyl dimethyl ketal; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2- (dimethylamino) ethyl benzoate, p-dimethylbenzoic acid ethyl ester; 1,2-octanedione, 1 -[4- (Phenylthio)-, 2- (O-benzoyloxime)], Etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1-( Oxime esters such as O-acetyloxime); bis (η5-2,4-cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-1-yl) phenyl) titanium, Bis (cyclopentadienyl) -bis [2,6-difluoro-3- (2- (1-pyr-1-yl) ethyl) phenyl] Titanosenes such as titanium; phenyldisulfide 2-nitrofluorene, butyroine, aniso Examples thereof include inethyl ether, azobisisobutyronitrile, tetramethylthium disulfide and the like. Of these, monoacylphosphine oxides and oxime esters are preferable, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole) −3-Il] −, 1- (O-acetyloxime) is more preferable. As the photopolymerization initiator (C), one type may be used alone, or two or more types may be used in combination.

The blending amount of the (C) photopolymerization initiator is preferably 0.01 to 30 parts by mass, more preferably 0, based on 100 parts by mass of the total of the (A) carboxyl group-containing resin and (B) carboxyl group-containing resin. It is 0.01 to 20 parts by mass. (C) When the blending amount of the photopolymerization initiator is 0.01 parts by mass or more, the photocurability on copper is good, the coating film is hard to peel off, and the coating film characteristics such as chemical resistance are good. Become. On the other hand, when the blending amount of the (C) photopolymerization initiator is 30 parts by mass or less, the light absorption of the (C) photopolymerization initiator is good and the deep curability is improved.

((D) Epoxy resin)
Examples of the (D) epoxy resin include the same epoxy resins as those mentioned as the components for synthesizing the (A) carboxyl group-containing resin. As the epoxy resin (D), one type may be used alone, or two or more types may be used in combination.

The blending amount of the (D) epoxy resin is the ratio of the equivalent amount of the epoxy group contained in the (D) epoxy resin to the total equivalent amount of the carboxyl groups contained in the (A) carboxyl group-containing resin and (B) the carboxyl group-containing resin. , 1.0 to 2.4, more preferably 1.2 to 2.2. When the ratio of the equivalents is 1.0 or more, the residual amount of carboxyl groups is low, and when the ratio of the equivalents is 2.4 or less, the residual amount of epoxy groups is low, so that chemical resistance, etc. Is improved.

The curable resin composition of the present invention may contain a thermosetting component other than the (D) epoxy resin such as an oxetane compound, a melamine resin, and a silicone resin as long as the effects of the present invention are not impaired.

(Compound with ethylenically unsaturated group)
The curable resin composition of the present invention can contain a compound having an ethylenically unsaturated group. As the compound having an ethylenically unsaturated group, a photopolymerizable oligomer, a photopolymerizable vinyl monomer, or the like, which are known and commonly used photocurable monomers, can be used. As the compound having an ethylenically unsaturated group, one type may be used alone, or two or more types may be used in combination.

Examples of the photopolymerizable oligomer include unsaturated polyester-based oligomers and (meth) acrylate-based oligomers. Examples of the (meth) acrylate-based oligomer include epoxy (meth) acrylates such as phenol novolac epoxy (meth) acrylate, cresol novolac epoxy (meth) acrylate, and bisphenol type epoxy (meth) acrylate, urethane (meth) acrylate, and epoxy urethane (meth). ) Acrylic, polyester (meth) acrylate, polyether (meth) acrylate, polybutadiene-modified (meth) acrylate and the like.

As the photopolymerizable vinyl monomer, known and commonly used ones, for example, styrene derivatives such as styrene, chlorostyrene, α-methylstyrene; vinyl esters such as vinyl acetate, vinyl butyrate or vinyl benzoate; vinyl isobutyl ether, vinyl- Vinyl ethers such as n-butyl ether, vinyl-t-butyl ether, vinyl-n-amyl ether, vinyl isoamyl ether, vinyl-n-octadecyl ether, vinyl cyclohexyl ether, ethylene glycol monobutyl vinyl ether, triethylene glycol monomethyl vinyl ether; acrylamide, (Meta) acrylamides such as methacrylicamide, N-hydroxymethylacrylamide, N-hydroxymethylmethacrylicamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-butoxymethylacrylamide; triallyl isocyanurate, diallyl phthalate, Allyl compounds such as diallyl isophthalate; 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tetrahydrofurfreel (meth) acrylate, isobolonyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, etc. (Meta) acrylic acid esters; hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate; methoxyethyl (meth) acrylate, ethoxyethyl Alkoxyalkylene glycol mono (meth) acrylates such as (meth) acrylate; ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di ( Alkylene polyol poly (meth) acrylates such as meta) acrylate, trimethylolpropantri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate; diethylene glycol di (meth) acrylate, triethylene glycol di Polyoxyalkylene glycol poly (meth) acrylates, ethoxylated trimetylolpropan triacrylates, propoxylated trimethylol propantri (meth) acrylates, etc. Ta) Acrylate; Poly (meth) acrylates such as neopentyl glycol hydroxypylate di (meth) acrylate; Isocyanurate-type poly (meth) acrylates such as tris [(meth) acryloxyethyl] isocyanurate Can be mentioned.

The blending amount of the compound having an ethylenically unsaturated group is appropriately in the range of 0.1 to 40 parts by mass with respect to 100 parts by mass in total of the (A) carboxyl group-containing resin and (B) carboxyl group-containing resin. When the compounding amount of the compound having an ethylenically unsaturated group is 0.1 parts by mass or more, the photocurable effect becomes good. On the other hand, when it is 40 parts by mass or less, the dryness to the touch of the coating film becomes good.

(Thermosetting catalyst)
The curable resin composition of the present invention can contain a thermosetting catalyst. Examples of the thermosetting catalyst include imidazole, 2-methylimidazole, 2-ethyl imidazole, 2-ethyl-4-methyl imidazole, 2-phenyl imidazole, 4-phenyl imidazole, 1-cyanoethyl-2-phenyl imidazole, 1-. Imidazole derivatives such as (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzyl Examples thereof include amine compounds such as amines, 4-methyl-N and N-dimethylbenzylamine, hydrazine compounds such as adipic acid dihydrazide and sebasic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. In addition, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine-isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine-isocyanulic acid adduct can also be used, preferably as these adhesion-imparting agents. A compound that also functions is used in combination with a thermosetting catalyst. One type of thermosetting catalyst may be used alone, or two or more types may be used in combination.

The blending amount of the thermosetting catalyst is preferably 0.01 to 25 parts by mass, and more preferably 0.1 to 15 parts by mass with respect to 100 parts by mass of the epoxy resin (D).

(Inorganic filler)
The curable resin composition of the present invention can contain an inorganic filler. Examples of the inorganic filler include barium sulfate, barium titanate, silicon oxide powder, finely divided silicon oxide, silica, talcite, hydrotalcite, Neuburg silica soil, clay, magnesium carbonate, calcium carbonate, aluminum oxide, and aluminum hydroxide. Known and commonly used fillers such as mica powder can be used. Among these, barium sulfate and silica are preferable. As the inorganic filler, one type may be used alone, or two or more types may be used in combination.

The inorganic filler is preferably surface-treated. Here, the surface treatment of the inorganic filler refers to a treatment for improving the compatibility with the resin component. The surface treatment of the inorganic filler may be either a surface treatment in which a curable reactive group can be introduced into the surface of the inorganic filler or a surface treatment in which a curable reactive group is not introduced. Here, the curable reactive group is not particularly limited as long as it is a group that cures with a curable compound such as (A), (B) carboxyl group-containing resin or (D) epoxy resin, and is a photocurable reactive group. However, it may be a thermosetting reactive group. Examples of the photocurable reactive group include a methacryl group, an acrylic group, a vinyl group, a styryl group and the like, and examples of the thermosetting reactive group include an epoxy group, an amino group, a hydroxyl group, a carboxyl group, an isocyanate group, an imino group and an oxetanyl. Examples thereof include a group, a mercapto group, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, an oxazoline group and the like. The method for introducing the curable reactive group onto the surface of the inorganic filler is not particularly limited, and it may be introduced by using a known and commonly used method, and a surface treatment agent having a curable reactive group, for example, a curable reactive group is introduced as an organic group. The surface of the inorganic filler may be treated with a coupling agent or the like having the above. As the coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, an aluminum coupling agent and the like can be used. Examples of the surface-treated inorganic filler having no curable reactive group include silica-alumina surface treatment, titanate-based coupling agent treatment, aluminate-based coupling agent treatment, and organically treated inorganic filler. Can be mentioned.

The blending amount of the inorganic filler is preferably 10 to 500 parts by mass, more preferably 20 to 200 parts by mass, based on 100 parts by mass of the total of the (A) carboxyl group-containing resin and (B) carboxyl group-containing resin. When the mixing ratio of the inorganic filler is 10 to 500 parts by mass, the viscosity of the composition does not become too high, the coatability is good, and a cured product having excellent properties as a solder resist can be obtained.

(Colorant)
The curable resin composition of the present invention can contain a colorant. As the colorant, known colorants such as red, blue, green, yellow, black, and white can be used, and any of pigments, dyes, and pigments may be used. However, it is preferable that it does not contain halogen from the viewpoint of reducing the environmental load and affecting the human body. As the colorant, one type may be used alone, or two or more types may be used in combination.

(Organic solvent)
The curable resin composition of the present invention may contain an organic solvent for the purpose of synthesizing a carboxyl group-containing resin, preparing the composition, adjusting the viscosity when applied to a base material or a carrier film, and the like. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; alcohols such as ethanol, methanol, propanol, isopropanol, cyclohexanol, ethylene glycol and propylene glycol: cyclohexane. , Alicyclic hydrocarbons such as methylcyclohexane; cellosolve, methylcellosolve, butylcellosolve, carbitol, methylcarbitol, butylcarbitol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol Glycol ethers such as diethyl ether, diethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether, tripropylene glycol monomethyl ether; ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, Esters such as propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. , Known and commonly used organic solvents can be used. One of these organic solvents may be used alone, or two or more thereof may be used in combination.

(Other ingredients)
The curable resin composition of the present invention may contain other additives known and commonly used in the field of electronic materials. Other additives include thermal polymerization inhibitors, UV absorbers, silane coupling agents, plasticizers, flame retardants, antistatic agents, anti-aging agents, antibacterial / antifungal agents, antifoaming agents, leveling agents, thickening agents. Agent, adhesion imparting agent, thixo property imparting agent, photoinitiator aid, sensitizer, photobase generator, thermoplastic resin, organic filler, mold release agent, surface treatment agent, dispersant, dispersion aid, surface modification Examples include pledge agents, stabilizers, and phosphors.

The curable resin composition of the present invention can contain an elastomer, but from the viewpoint of resolution, it is preferable not to blend the elastomer, and even if it is blended, the (A) carboxyl group is preferable. It is 0.1 to 5 parts by mass with respect to 100 parts by mass of the total of the containing resin and the (B) carboxyl group-containing resin.

Examples of the elastomer include polyester-based elastomers, polyurethane-based elastomers, polyester-urethane-based elastomers, polyamide-based elastomers, polyesteramide-based elastomers, acrylic-based elastomers, and olefin-based elastomers. Further, a resin obtained by modifying a part or all of the epoxy groups of the epoxy resin having various skeletons with both-terminal carboxylic acid-modified butadiene-acrylonitrile rubber and the like can be mentioned. Examples thereof include epoxy-containing polybutadiene-based elastomers, acrylic-containing polybutadiene-based elastomers, hydroxyl group-containing polybutadiene-based elastomers, and hydroxyl group-containing isoprene-based elastomers.

The curable resin composition of the present invention may be used as a dry film or as a liquid. When used as a liquid, it may be one-component or two-component or more, but it is preferably two-component or more from the viewpoint of storage stability.

Next, the dry film of the present invention has a resin layer obtained by applying the curable resin composition of the present invention on a carrier film and drying it. When forming a dry film, first, the curable resin composition of the present invention is diluted with the above organic solvent to adjust the viscosity to an appropriate level, and then a comma coater, a blade coater, a lip coater, a rod coater, and a squeeze coater. , Reverse coater, transfer coater, gravure coater, spray coater, etc., and apply to a uniform thickness on the carrier film. Then, the applied composition is usually dried at a temperature of 40 to 130 ° C. for 1 to 30 minutes to form a resin layer. The coating film thickness is not particularly limited, but is generally selected as appropriate in the range of 3 to 150 μm, preferably 5 to 60 μm after drying.

As the carrier film, a plastic film is used, and for example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film and the like can be used. The thickness of the carrier film is not particularly limited, but is generally selected as appropriate in the range of 10 to 150 μm. More preferably, it is in the range of 15 to 130 μm.

After forming the resin layer made of the curable resin composition of the present invention on the carrier film, a peelable cover is further applied to the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer. It is preferable to stack the films. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, surface-treated paper, or the like can be used. The cover film may be smaller than the adhesive force between the resin layer and the carrier film when the cover film is peeled off.

In the present invention, the curable resin composition of the present invention may be applied onto the cover film and dried to form a resin layer, and a carrier film may be laminated on the surface thereof. That is, either a carrier film or a cover film may be used as the film to which the curable resin composition of the present invention is applied when producing the dry film in the present invention.

The printed wiring board of the present invention has a cured product obtained from the curable resin composition of the present invention or the resin layer of a dry film. Further, in the method for producing a printed wiring board of the present invention, the curable resin composition is applied and dried on a base material, or the resin layer of the dry film is laminated and the resin layer is formed on the base material. The step of forming the resin layer, the photocuring step of selectively irradiating the resin layer on the base material with light to cure the resin, the developing step of removing the unirradiated portion by development after the photocuring step to obtain the pattern layer, and the light It includes a light irradiation step of irradiating and a step of heating the light-irradiated pattern layer. For example, the curable resin composition of the present invention is adjusted to a viscosity suitable for the coating method using the above organic solvent, and the dip coating method, the flow coating method, the roll coating method, the bar coater method, etc. After coating by a method such as a screen printing method or a curtain coating method, the organic solvent contained in the composition is volatilized and dried (temporarily dried) at a temperature of 60 to 100 ° C. to form a tack-free resin layer on the substrate. To form. Further, in the case of a dry film, the resin layer is formed on the base material by sticking it on the base material so that the resin layer comes into contact with the base material by a laminator or the like, and then peeling off the carrier film.

The base material includes a printed wiring board and a flexible printed wiring board whose circuit is formed of copper or the like in advance, as well as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, and glass cloth / paper epoxy. , Synthetic fiber epoxy, fluororesin / polyethylene / polyimideene ether, polyphenylene oxide / cyanate, etc. are used for high frequency circuit copper-clad laminates, etc., and all grades (FR-4, etc.) of copper-clad laminates are used. Plates, other metal substrates, polyimide films, PET films, polyethylene naphthalate (PEN) films, glass substrates, ceramic substrates, wafer plates and the like can be mentioned.

The drying performed after applying the curable resin composition of the present invention is performed by using a hot air circulation type drying furnace, an IR furnace, a hot plate, a convection oven, or the like (using a steam-based air heating type heat source) and hot air in the dryer. Can be carried out by using a method of countercurrent contact and a method of spraying from a nozzle onto a base material having a resin layer).

After forming the resin layer on the base material, it is selectively irradiated with light through a photomask having a predetermined pattern formed, and the unirradiated portion is subjected to, for example, a dilute alkaline aqueous solution (for example, 0.3 to 3 mass% sodium carbonate aqueous solution). It is removed by development to form a pattern layer of the cured product. Further, by irradiating the cured product with light and then heat-curing (for example, 100 to 220 ° C.), the final finish curing (main curing) is performed, so that the effects of the present invention can be obtained in addition to various properties such as adhesion and hardness. A working cured film can be easily formed.

The exposure machine used for the above light irradiation may be a device equipped with a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc., and irradiates light in the range of 300 to 450 nm. A drawing device (for example, a laser direct imaging device that directly draws an image with a laser based on CAD data from a computer) can also be used. The lamp light source or the laser light source of the direct drawing machine may have a maximum wavelength in the range of 300 to 450 nm. The exposure amount for image formation varies depending on the film thickness and the like, but can be generally in the range of 10 to 1000 mJ / cm ² , preferably 20 to 800 mJ / cm ² . Further, the light irradiation condition after obtaining the pattern layer is preferably an exposure amount of 500 to 3000 mJ / cm ² .

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

The curable resin composition of the present invention is suitably used for forming a cured film on a printed wiring board such as a package substrate, more preferably used for forming a permanent film, and more preferably. , Solder resists, interlayer insulating layers, coverlays, and more preferably used to form solder resists. Further, it can be suitably used for forming a permanent coating such as a solder resist of a printed wiring board exposed to a high temperature state for in-vehicle use.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples. In the following, "part" and "%" are all based on mass unless otherwise specified.

[Synthesis of alkali-soluble resin]
(Synthesis Example 1: Synthesis of Carboxylic Group-Containing Resin A-1)
Put 220 parts (1 equivalent) of cresol novolac type epoxy resin ECON-104S (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent = 220) into a four-necked flask equipped with a stirrer and a reflux condenser, and add 218 parts of carbitol acetate. In addition, it was melted by heating. Next, 0.46 parts of methyl hydroquinone was added as a polymerization inhibitor, and 1.38 parts of triphenylphosphine was added as a reaction catalyst. The mixture was heated to 95-105 ° C., 50.4 parts (0.7 equivalents) of acrylic acid and 41.5 parts (0.3 equivalents) of p-hydroxyphenethyl alcohol were gradually added dropwise, and the mixture was reacted for 16 hours. .. This reaction product (hydroxyl group: 1.3 equivalents) was cooled to 80 to 90 ° C., 91.2 parts (0.6 equivalents) of tetrahydrophthalic anhydride was added, reacted for 8 hours, cooled, and then taken out. .. The solution of the photosensitive carboxyl group-containing resin thus obtained had a non-volatile content of 65% by mass and a solid acid value of 83 mgKOH / g. Hereinafter, this solution will be referred to as (A) carboxyl group-containing resin A-1.

(Synthesis Example 2: Synthesis of Carboxylic Acid Group-Containing Resin B-1)
In a 2 liter separable flask, 411.4 g of ethylcarbitol acetate, o-cresol novolac type epoxy resin [manufactured by Nippon Kayaku Co., Ltd., EOCN-103S, epoxy equivalent 215, softening point 83 ° C.] 430 g and 144 g of acrylic acid ( 2 mol) was charged. The mixture was heated to 120 ° C. with stirring, and the reaction was continued for 10 hours while maintaining 120 ° C. Once the reaction product was cooled to room temperature, 190 g (1.9 mol) of succinic anhydride was added, and the mixture was heated to 80 ° C. and reacted for 4 hours. Once again, the reaction product was cooled to room temperature. The acid value of this reaction product as a solution was 91 mgKOH / g, and the acid value of the resin was 140 mgKOH / g. 85.2 g (0.6 mol) of glycidyl methacrylate and 45.9 g of propylene glycol methyl ether acetate were added to this reaction product, and the mixture was heated to 110 ° C. with stirring, and the reaction was continued for 6 hours while maintaining 110 ° C. When the reaction product was cooled to room temperature, a viscous solution was obtained. The non-volatile content of the solution of the photosensitive carboxyl group-containing resin thus obtained was 65% by mass, and the solution showed an acid value of 56 mgKOH / g. This solution is referred to as (B) carboxyl group-containing resin B-1.

(Examples 1 to 3, Comparative Examples 1 and 2)
According to the formulation shown in Table 1 below, each component was compounded, stirred, and dispersed in three rolls to prepare a curable resin composition. The blending amount in Table 1 indicates a part by mass.

(Measurement of glass transition temperature (Tg))
The curable resin composition was applied to the entire surface on a copper foil, dried at 80 ° C. for 30 minutes, irradiated with light at 600 mJ / cm ² on a mylar film with a high-pressure mercury lamp, developed with a 1 wt% sodium carbonate aqueous solution at 30 ° C., and 1000 mJ. / cm ² and light irradiation by a high pressure mercury lamp gave the cured film by thermal curing at 0.99 ° C. 60 minutes. The obtained cured film was peeled off from the copper foil.
The glass transition point of the cured film was determined by dynamic viscoelasticity measurement (DMA) under the following conditions.
Measurement temperature: -30 to 300 ° C
Heating rate: 5 ° C / min

(Measurement of breaking point strength and breaking point elongation)
The curable resin composition was spread over the entire surface on a copper foil, dried at 80 ° C. 30 min, then exposed Mylar film on 600 mJ / cm ^2, developed with 1 wt% sodium carbonate aqueous solution of 30 ° C., at 1000 mJ / cm ² The cured film obtained by irradiating light with a high-pressure mercury lamp and thermosetting at 150 ° C. for 60 minutes was peeled off from the copper foil.
The cured film was cut into test pieces having a width of about 5 mm and a length of about 80 mm, and the strength at the breaking point and the elongation at the breaking point were measured using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-100N). .. The measurement conditions were a sample width of about 10 mm, a distance between fulcrums of about 40 mm, a tensile speed of 1.0 mm / min, a tensile elastic modulus at the breaking point as the breaking point strength, and an elongation to the breaking point as the breaking point elongation. did.

(Evaluation of resolution)
In the same manner as in the measurement of the glass transition temperature, a cured product pattern of the curable resin composition having an opening of 100 μm was formed on copper and observed by an SEM (scanning electron microscope). The obtained opening shape was confirmed and evaluated according to the following criteria.
◯: Good opening can be performed without unevenness on the wall surface of the opening of the cured product.
Δ: It is possible to form an opening in the cured product, but unevenness is generated on the wall surface of the opening.
X: The opening could not be performed.

＊１：合成例１で合成したカルボキシル基含有樹脂Ａ−１（固形分０．６５質量％）
＊２：合成例２で合成したカルボキシル基含有樹脂Ｂ−１（固形分０．６５質量％）
＊３：日本化薬社製ＥＰＰＮ−２０１
＊４：三菱化学社製ｊＥＲ ＹＸ−４０００
＊５：日本化薬社製ＫＡＹＡＲＡＤ ＤＰＨＡ
＊６：信越シリコーン社製
＊７：ＢＡＳＦジャパン社製イルガキュアＴＰＯ（２，４，６−トリメチルベンゾイル−ジフェニル−フォスフィンオキサイド）
＊８：堺化学社製
＊９：有機溶剤

* 1: Carboxylic acid group-containing resin A-1 synthesized in Synthesis Example 1 (solid content 0.65% by mass)
* 2: Carboxylic acid group-containing resin B-1 synthesized in Synthesis Example 2 (solid content 0.65% by mass)
* 3: EPPN-201 manufactured by Nippon Kayaku Co., Ltd.
* 4: Mitsubishi Chemical jER YX-4000
* 5: KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.
* 6: Made by Shinetsu Silicone Co., Ltd. * 7: Irgacure TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide) manufactured by BASF Japan Ltd.
* 8: Made by Sakai Chemical Co., Ltd. * 9: Organic solvent

From the results shown in the above table, it can be seen that the cured product obtained from the curable resin composition of the present invention has a high glass transition temperature and is excellent in strength and flexibility.

Claims (6)

(A) A photosensitive carboxyl group-containing resin, which is a reaction product of an epoxy resin, a compound containing a phenolic hydroxyl group and an alcoholic hydroxyl group, an unsaturated carboxylic acid (A1), and a polybasic acid anhydride.
(B) A reaction product of an epoxy resin and an unsaturated carboxylic acid (B1), a reaction product of a polybasic acid anhydride (B2), and a reaction product of a compound having an oxylane ring and an ethylenically unsaturated group. Photosensitive carboxyl group-containing resin,
(C) Photopolymerization initiator and
(D) A curable resin composition containing an epoxy resin. The curable resin according to claim 1, wherein the compounding ratio (mass ratio) of the (A) carboxyl group-containing resin and the (B) carboxyl group-containing resin is 3: 7 to 7: 3. Composition. A dry film characterized by having a resin layer obtained by applying the curable resin composition according to claim 1 or 2 onto a film and drying the film. A cured product obtained by curing the curable resin composition according to claim 1 or 2 or the resin layer of the dry film according to claim 3. A printed wiring board comprising the cured product according to claim 4. The curable resin composition according to claim 1 or 2 is applied and dried on the base material, or the resin layer of the dry film according to claim 3 is laminated to form a resin layer on the base material. The process of forming,
A photo-curing step of selectively irradiating the resin layer on a substrate with light to photo-curing the resin layer.
A development process that removes unirradiated parts by development after the photo-curing process to obtain a pattern layer.
A light irradiation process that irradiates the pattern layer with light, and
A method for manufacturing a printed wiring board, which comprises a step of heating the light-irradiated pattern layer.