JPH08311195A - Photosensitive resin and its composition - Google Patents

Abstract

PURPOSE: To obtain a photosensitive resin having a specific chemical structure, developable with an alkali, having excellent storage stability and heat resistance and useful for the production of printed circuit board, etc. CONSTITUTION: This photosensitive resin is expressed by formula [R1 and R2 are each H, a 1-5C alkyl or a halogen; X is CO, SO2 , CH2 , C(CF3 )2 , etc.; a part of Y is an unsaturated isocyanate residue and a part of the remaining Y is residue of an (un)saturated polybasic acid anhydride; n is an integer of >=1] and has an acid value of 50-200mgKOH/g. The photosensitive resin is produced by reacting a part of hydroxyl groups of a bisphenol-type epoxyacrylate resin with an unsaturated isocyanate compound having one or more ethylenically unsaturated groups (the amount of the isocyanate compound is >=0.2 equivalent based on 1 equivalent of the hydroxyl group of the bisphenol-type epoxyacrylate resin) and reacting a part of the remaining Y with an (un)saturated polybasic acid anhydride (the amount of the anhydride is >=0.2 equivalent based on 1 equivalent of the hydroxyl group of the acrylate resin).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention can be used in the fields of printed wiring board manufacturing and precision metal processing, and is particularly suitable for use in fields requiring heat resistance such as solder resists. TECHNICAL FIELD The present invention relates to a photosensitive resin composition which is possible and has good storage stability, and a photosensitive resin for obtaining the same.

[0002]

2. Description of the Related Art In recent years, progress in the technical field of semiconductors has been remarkable, and along with this, the era of integrated circuits has changed from LSIs to ultra-LSIs, and electronic devices have been rapidly reduced in size, increased in performance, and increased in functionality. . Corresponding to this, the printed wiring boards are becoming higher in density and wiring, and the surface mounting of components is progressing.
Furthermore, higher precision and higher performance than ever before are required.

In order to meet this demand, various studies have been made on a solder resist and a method for forming the solder resist, but they are not always satisfactory. For example, in the conventional screen printing method, which has been widely used for consumer use because of its high processing capacity and easy operation, bleeding, bleeding, dripping during printing, and printing accuracy due to screen expansion and contraction are problems. , It is not possible to deal with the recent manufacturing of high-density printed wiring boards. Therefore, a photo solder resist method for forming a pattern by a photographic method has been developed.

In this photo solder resist method, for example, a film of a developable photosensitive resin composition is formed on a substrate,
It is a method of forming a solder mask having sufficient heat resistance and resolution by performing pattern exposure on this coating and developing it to remove the exposed or unexposed portions.

As a photosensitive resin composition that can be used in the photo solder resist method, conventionally, for example, a composition mainly containing a photosensitive epoxy resin having a chalcone group in the main chain and an epoxy resin curing agent (Japanese Patent Laid-Open No. 58-58). -62636 publication)
And a composition containing a novolac type epoxy acrylate having an epoxy group and a photopolymerization initiator as main components (Japanese Patent Laid-Open Publication No. 6-58242).
No. 1-272) and the like are known. However, since these use an organic solvent as a developing solution, there are problems in environmental pollution and environmental hygiene.

Therefore, a photo solder resist which can be developed with an alkaline aqueous solution has been studied. For example 1-5
No. 4390 discloses a liquid solder resist ink composition containing an oligomer obtained by further reacting a reaction product of a novolac type epoxy resin and acrylic acid with an acid anhydride, a photopolymerization initiator, an epoxy resin and a diluent. Is proposed. Further, JP-A-5-339356 discloses a photopolymerizable unsaturated compound obtained by further reacting an acid anhydride with a reaction product of a bisphenol A type epoxy resin and acrylic acid, an epoxy resin and a photopolymerization initiator. An alkaline developing type photosensitive resin composition containing the same is disclosed.

[0007]

The above-mentioned alkali-developable photosensitive resin composition can be developed with an aqueous alkali solution and has excellent performance as a solder mask, such as resolution, heat resistance, electrical properties and mechanical properties. ing. However, for example, after adding an epoxy resin, which is a thermosetting component, to this composition, when it is stored at 40 ° C., it gels and becomes unusable in about one day, and there is a problem in storage stability, and practical use occurs. There was an inconvenience. Therefore, improvement of this storage stability has been strongly demanded.

The present invention has been made to solve the above-mentioned problems, and therefore the object thereof is excellent in heat resistance, adhesion to a substrate, resolution, electric characteristics, mechanical characteristics, and development with an alkaline aqueous solution. The present invention provides a photosensitive resin composition having excellent storage stability, and a novel photosensitive resin used for the photosensitive resin composition.

[0009]

The above-mentioned problems are solved by the following general formula (1)

[0010]

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(Wherein R ₁ and R ₂ are hydrogen atoms and have 1 to 1 carbon atoms)
An alkyl group of 5, or a halogen atom, X is —CO—,
_{-SO 2 -, - CH 2 -} , - C (CF 3) 2 -, - Si (C
_{H 3) 2 -, - C} (CH 3) 2 -, - O- or indicates direct, Y is partially unsaturated isocyanate residue,
It is possible to solve the problem by providing a photosensitive resin represented by the above formula (n is an integer of 1 or more), at least a part of which is a residue of a saturated or unsaturated polybasic acid anhydride.

In this photosensitive resin, for example, a part of hydroxyl groups of a bisphenol type epoxy acrylate resin is reacted with an unsaturated isocyanate compound having at least one ethylenically unsaturated group, and at least another part thereof is saturated or saturated. It can be produced by reacting with an unsaturated polybasic acid anhydride. The above-mentioned unsaturated isocyanate residue is 0. 0 per hydroxyl group of the bisphenol type epoxy acrylate resin.
It is preferably 2 equivalents or more, and the saturated or unsaturated polybasic acid anhydride residue is preferably 0.2 equivalents or more per hydroxyl group of the bisphenol epoxy acrylate resin. This photosensitive resin has an acid value of 50 mgKOH / g to 20.
It is preferably within the range of 0 mgKOH / g.

The present invention also provides the above-mentioned photosensitive resin (hereinafter,
An alkali-developable photosensitive resin composition (hereinafter referred to as “photosensitive resin A”) and an epoxy compound having at least one epoxy group in the molecule (hereinafter referred to as “epoxy compound B”) The present composition "). The composition preferably contains a photopolymerization initiator or sensitizer sufficient to cause photopolymerization. The composition preferably also contains a compound having at least one ethylenically unsaturated group in the molecule (hereinafter referred to as “unsaturated compound C”).

Next, the photosensitive resin A of the present invention will be described in detail. The photosensitive resin A represented by the above general formula (1) is a novel compound, and has a bisphenol type epoxy acrylate resin as a skeleton, and an unsaturated isocyanate residue is bonded to a part of the hydroxyl group, and the balance of the hydroxyl group remains. The structural feature is that a residue of a saturated or unsaturated polybasic acid anhydride is bonded to at least a part of the above.

In the unexposed state, the photosensitive resin A is alkali-soluble and photopolymerizable. And it can be photopolymerized or photocopolymerized alone or with the unsaturated compound C, which makes it alkali-insoluble. The photosensitive resin A and its photopolymerized product react with the epoxy compound B under heating to give a cured product. It was found that this cured product had high heat resistance and was excellent in adhesion to a substrate, electrical properties, and mechanical properties. In addition, the present invention containing the photosensitive resin A and the epoxy compound B (and the unsaturated compound C) was found to have extremely good storage stability without gelation even after long-term storage, and arrived at the present invention. .

In the photosensitive resin A represented by the general formula (1),
Examples of bisphenol residues in which X is -CO- include:
Examples thereof include bis (4-hydroxyphenyl) ketone, bis (4-hydroxy-3,5-dimethylphenyl) ketone, and bis (4-hydroxy-3,5-dichlorophenyl) ketone. X is -SO ₂ -
Examples of the bisphenol residue are bis (4-hydroxyphenyl) sulfone, bis (4-hydroxy-3,5-dimethylphenyl) sulfone, bis (4-hydroxy-3,5-dichlorophenyl) sulfone, etc. Can be mentioned. Examples of the bisphenol residue in which X is —CH ₂ — include, for example, bis (4-hydroxyphenyl) methane and bis (4-hydroxy-).
Examples include 3,5-dimethylphenyl) methane and bis (4-hydroxy-3,5-dichlorophenyl) methane. Examples of the bisphenol residue in which X is —C (CF ₃ ) ₂ — include, for example, bis (4-hydroxyphenyl) hexafluoropropane, bis (4-hydroxy-3,5-dimethylphenyl) hexafluoropropane, Examples thereof include bis (4-hydroxy-3,5-dichlorophenyl) hexafluoropropane. X is -Si (CH _{3) 2} - Examples of bisphenol residues are, for example, bis (4-hydroxyphenyl) dimethylsilane, bis (4-hydroxy-3,5
Examples thereof include dimethylphenyl) dimethylsilane and bis (4-hydroxy-3,5-dichlorophenyl) dimethylsilane. X is -C (CH _{3) 2} - Examples of bisphenol residues are, for example, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethyl Phenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-)
Examples thereof include 3-methylphenyl) propane and 2,2-bis (4-hydroxy-3-chlorophenyl) propane. Examples of the bisphenol residue in which X is -O- include, for example, bis (4-hydroxyphenyl).
Ether, bis (4-hydroxy-3,5-dimethylphenyl) ether, bis (4-hydroxy-3,5-dichlorophenyl) ether and the like can be mentioned.
Further, as an example of a bisphenol residue in which X represents a direct bond,
For example, 4,4'-biphenol, 3,3'-biphenol, etc. can be mentioned. Of course, the bisphenol residue contained in the photosensitive resin A of the present invention is not limited to the above examples. Further, these bisphenol residues may be mixed in the molecule or intermolecularly.

In the photosensitive resin A represented by the general formula (1), a part of Y is an unsaturated isocyanate residue, and at least another part thereof is a residue of a saturated or unsaturated polybasic acid anhydride. Is. Therefore, the molecule always contains both an unsaturated isocyanate residue and the above acid anhydride residue. However, it does not necessarily have to be constituted by both of them, and it is not excluded that a part of Y is, for example, a hydrogen atom. Among them, the unsaturated isocyanate residue is generated by the reaction between the hydroxyl group of the bisphenol type epoxy acrylate resin and the unsaturated isocyanate, and the unsaturated isocyanate that can be used in this reaction is at least 1 in the molecule. A compound having one isocyanate group and at least one ethylenically unsaturated group. This unsaturated isocyanate can generally be prepared by reacting an amine compound having at least one ethylenically unsaturated group in the molecule with phosgene.

Examples of unsaturated isocyanates that can be used in this reaction include (meth) acryloyl isocyanate, (meth) acryloyloxyethyl isocyanate and (meth) acryloyloxypropyl isocyanate.

In the photosensitive resin A represented by the general formula (1), examples of the acid anhydride which can be used for forming the residue of the saturated or unsaturated polybasic acid anhydride which is a part of Y are: , Maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, Dibasic acid anhydrides such as chlorendic anhydride and methyltetrahydrophthalic anhydride; aromatic polyvalent carboxylic anhydrides such as trimellitic anhydride, pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride; and others such as 5 -(2
5-dioxotetrahydrofuryl) -3-methyl-3-
Examples thereof include polyvalent carboxylic acid anhydride derivatives such as cyclohexene-1,2-dicarboxylic acid anhydride.

The photosensitive resin A can be manufactured, for example, as follows. First, for example, the following formula (2),

[0021]

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A bisphenol A type epoxy acrylate resin represented by the formula (1) is used as a starting material and reacted with an unsaturated isocyanate such as (meth) acryloyloxyethyl isocyanate in an amount smaller than its hydroxyl equivalent, to obtain a compound. The above acid anhydride is heated and reacted in a ketone or cellosolve solvent. In this case, the unsaturated isocyanate residue is 0.2 equivalent or more per hydroxyl group of the bisphenol epoxy acrylate resin, and the saturated or unsaturated polybasic acid anhydride residue is 0 per hydroxyl group of the bisphenol epoxy acrylate resin. ．
It is preferable to use the unsaturated isocyanate and the acid anhydride in an amount ratio so as to be 2 equivalents or more. If the unsaturated isocyanate residue is less than 0.2 equivalent per hydroxyl group of the bisphenol type epoxy acrylate resin, the physical properties of the cured film, such as heat resistance and solvent resistance, are insufficient, which is not preferable. On the other hand, if the saturated or unsaturated polybasic acid anhydride residue is less than 0.2 equivalent, it is not preferable because the alkali developability, which is the object of the present invention, is insufficient.

The acid value of the photosensitive resin A of the present invention is preferably in the range of 50 mgKOH / g to 200 mgKOH / g. Acid value is 50mgKOH
If it is less than 100 g / g, it is insufficient to develop the high resolution which is the object of the present invention, and the acid value is 200 mgKOH /
If it exceeds g, the photo-cured film is likely to swell due to the development treatment after exposure. From this viewpoint, the acid value is 70 mgKOH /
More preferably, it is in the range of g to 180 mg KOH / g.

Next, the photosensitive resin composition (present composition) containing the photosensitive resin A and the epoxy compound B will be described. This composition basically contains a photosensitive resin A and an epoxy compound B having at least one epoxy group in the molecule, but in practice, a photopolymerization initiator and / or a sensitizer (hereinafter , Collectively referred to as “initiator”). Still further, the composition may contain an unsaturated compound C having at least one ethylenically unsaturated group in the molecule.

The epoxy compound B constituting the present composition in combination with the photosensitive resin A may be a polymer or a monomer as long as it has at least one epoxy group in the molecule. Epoxy compound B which is a polymer
Examples of the epoxy resin include phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, and alicyclic epoxy resin. Can be mentioned. Examples of the epoxy compound B that is a monomer include phenyl glycidyl ether, p-butylphenol glycidyl ether, triglycidyl isocyanurate, diglycidyl isocyanurate, allyl glycidyl ether, and glycidyl methacrylate.

When this epoxy compound B is incorporated into the present composition, it reacts with the photosensitive resin A or the photopolymerization product of the photosensitive resin A at the time of heating to give a cured product which is tough, heat resistant and chemical resistant. give. This cured product also has the property of strongly adhering to a glass epoxy resin substrate or a copper plate.

The epoxy compound B is a photosensitive resin A100.
It is preferable that the composition is blended in the composition in an amount of 10 to 75 parts by weight based on parts by weight. If it is less than 10 parts by weight, the properties of the composition of the present invention after curing, particularly alkali resistance, will be insufficient, and if it exceeds 75 parts by weight, cracks will occur during curing or the adhesiveness will deteriorate, which is inconvenient. is there. From this viewpoint, a particularly preferable blending ratio is within a range of 20 parts by weight to 55 parts by weight with respect to 100 parts by weight of the photosensitive resin A.

The photosensitive resin composition of the present invention may contain an unsaturated compound C. The unsaturated compound C is photopolymerizable in the presence of an initiator, and is photopolymerized with the photosensitive resin A to adjust the physical properties of the resulting polymerized film, such as flexibility and hardness, and to develop the film. It is useful for adjusting sex and resolution. From this viewpoint, the unsaturated compound C is also preferably alkali developable.

Examples of the unsaturated compound C include a carboxylic acid anhydride adduct of bisphenol type epoxy acrylate, a novolac type epoxy acrylate, and a carboxylic acid anhydride adduct of hydroxylethyl (meth) acrylate. Can be mentioned.

When the unsaturated compound C is used, its amount is preferably in the range of 10 to 50 parts by weight per 100 parts by weight of the photosensitive resin A. If it is less than 10 parts by weight, the effect of the compounding is not recognized, and if it exceeds 50 parts by weight, the storage stability of the composition may be impaired.

The composition preferably contains an initiator so that cross-linking polymerization takes place by exposure to low energy for a relatively short time. As the initiator, any compound generally used to initiate photopolymerization of the photosensitive resin and accelerate the photopolymerization reaction can be used. Examples thereof include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone and p-.
Acetophenones such as dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, pt-butylacetophenone; benzophenone,
Benzophenones such as 2-chlorobenzophenone and p, p′-bisdimethylaminobenzophenone; Benzoin ethers such as benzyl, benzoin, benzoin methyl ether, benzoin isopropyl ether and benzoin isobutyl ether; benzyl dimethyl ketal; thioxanthone, 2-chlorothioxanthone ,
Sulfur-containing compounds such as 2,4-diethylthioxanthone, 2-methylthioxanthone, and 2-isopropylthioxanthone; 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,
Anthraquinones such as 3-diphenylanthraquinone; Azobisisobutyronitrile; Organic peroxides such as benzoyl peroxide and cumene peroxide;
Examples thereof include thiols such as 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, and 2-mercaptobenzothiazole. These compounds may be used in combination of two or more kinds.

A compound which does not act as a photopolymerization initiator by itself but can increase the efficacy of the photopolymerization initiator when used in combination with the above compound may be added. Examples of this type of compound include, for example, tertiary amines such as triethanolamine, which are effective when used in combination with benzophenones.

The initiator is preferably added to the composition in an amount of 0.5 to 30 parts by weight per 100 parts by weight of the photosensitive resin A. If it is less than 0.5 part by weight, the photopolymerization rate of the composition is too slow to be practical. If it exceeds 30 parts by weight, it becomes difficult for light to reach the substrate, and the adhesion between the substrate and the resin film may be impaired. From this viewpoint, a particularly preferable blending ratio is within a range of 1 to 20 parts by weight with respect to 100 parts by weight of the photosensitive resin A.

The composition of the present invention may optionally contain additives generally used in this field, such as an epoxy group curing accelerator, a thermal polymerization inhibitor, a plasticizer, a leveling agent and an antifoaming agent. Good. Among these, as the epoxy group curing accelerator, for example, amine compounds, imidazole compounds,
Examples thereof include carboxylic acids, phenols, quaternary ammonium salts, and methylol-containing compounds. If a small amount of these epoxy group curing accelerators is added alone or in combination to the present composition, then the coating film is heated to obtain heat resistance, solvent resistance,
It is possible to improve various properties such as acid resistance, plating resistance, adhesion, electrical characteristics, and hardness.

Examples of the thermal polymerization inhibitor that can be added to the present composition include hydroquinone, hydroquinone monomethyl ether, pyrogallol, t-butylcatechol, phenothiazine and the like. As the plasticizer, dibutyl phthalate, dioctyl phthalate, tricresyl phosphoric acid, etc. can be used. Examples of the defoaming agent and leveling agent include silicone type, fluorine type,
An acrylic compound or the like is used.

The composition may further contain silicon oxide,
Known fillers such as talc, clay, calcium carbonate and barium sulfate, and known coloring materials such as phthalocyanine blue, phthalocyanine green, titanium oxide and carbon black may be contained.

The present composition can be produced by uniformly mixing the above-mentioned components in the presence or absence of a solvent. When a solvent is used, ketones such as methyl ethyl ketone and methyl isobutyl ketone, cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve and cellosolve acetate, or a mixture thereof can be preferably used. It goes without saying that when the composition is used as a coating liquid, and when it is formed into a dry film, it is preferable to once use the above solvent to form a solution or a viscous liquid.

Next, a method for forming a resist film on a substrate using the present composition will be described. In the following description, an example in which the present composition is used in the form of a solution will be described, but when it is used as a dry film, it can be treated essentially in the same manner according to a conventional dry film treatment method.

The composition in the form of a solution is adjusted in concentration with a solvent so as to have a concentration suitable for forming a film before being applied to a substrate, and if necessary, an additional photopolymerization initiator, a photopolymerization initiation auxiliary agent or a coupling agent is added. A resist solution is prepared by adding agents, antioxidants and the like. Next, this resist solution is applied to the substrate. As a coating method, in addition to the screen printing method, any coating method conventionally used in this field such as dip coating, spray coating, knife coating, roller coating, bar coating and spin coating can be used. The coating thickness of the resist solution is 1 μm to 5
The thickness is preferably 0 μm.

The resist solution coating film applied to the substrate is pre-baked to evaporate the solvent. This prebaking is preferably performed within a temperature range of 40 ° C to 110 ° C. Next, a photomask is closely adhered on the coating film, and UV exposure is performed. Examples of the light source suitable for ultraviolet exposure include an ultrahigh pressure mercury lamp, a high pressure mercury lamp, and a metal halide lamp.

The exposed coating film is brought into contact with an alkaline aqueous solution to carry out alkali development. Examples of the developer suitable for the alkali development include an aqueous solution of an alkali metal or alkaline earth metal carbonate, an aqueous solution of an alkali metal hydroxide, and the like. Particularly preferred are carbonates such as sodium carbonate, potassium carbonate and lithium carbonate. When a weak alkaline aqueous solution containing 1% to 3% by weight of these carbonates is used, a fine image can be developed precisely. In addition, ethanolamine, diethanolamine,
It is also possible to use a 1% by weight to 3% by weight aqueous solution of a basic organic compound such as triethanolamine or tetramethylammonium hydroxide.

The developing temperature is 10 ° C to 50 ° C, especially 20 ° C to
The temperature is preferably 40 ° C. This development can be performed by using a commercially available developing machine or an ultrasonic cleaning machine. As a result, a resist pattern formed by the coating film of the present composition is formed on the substrate. After the alkali development, the substrate on which the resist pattern is formed is thoroughly washed with water.

The resist pattern obtained here is preferably post-baked. This post-baking completely dry the coating, and at this stage, the free epoxy groups still remaining are reacted by heating to complete the curing, and the coating has alkali resistance, solvent resistance, heat resistance, glass and To improve various properties such as adhesion to metal such as copper, surface hardness, transparency, etc. to the high level required for solder resist, for example. This post-baking is preferably performed at a temperature of 80 ° C. to 200 ° C. for 10 minutes to 120 minutes, for example.

[0044]

Examples of the present invention will be described below. In the following description, “part” means part by weight unless otherwise specified. (Production of photosensitive resin A)

(Example 1) In a 300 ml four-necked flask, a bisphenol A type epoxy acrylate resin having a molecular weight of about 900 (90 g), di-n-butyltin diacetate (1 g) and dried and dehydrated propylene glycol monomethyl ether acetate. (Hereinafter referred to as “PGMEA”) (90 g) was charged and heated and stirred at 70 ° C. in a nitrogen stream to dissolve the resin. Next, methacryloyloxyethyl isocyanate (44.5 g) was added dropwise with the same amount of dry dehydrated PGMEA over 1 hour. Then, heating and stirring are continued until the absorption derived from the isocyanate disappears in the IR spectrum, and a photosensitive epoxy acrylate resin in which a part of the hydrogen atoms of the hydroxyl group in the formula (2) is replaced with a methacryloyloxyethylcarbamoyl group (hereinafter, "intermediate" A 50% PGMEA solution of "body a") was obtained.

A 50% PGMEA solution (269 g) of the above intermediate a was placed in a 300 ml four-necked flask and heated to 110 ° C. with stirring, and tetrahydrophthalic anhydride (30.4 g) was maintained while maintaining this temperature. ) Same amount of PGM
EA was added, and the stirring was stopped when the acid value of the reaction system dropped to about 63 mgKOH / g. Accordingly, in the general formula (1), R ₁ and R ₂ are both hydrogen atoms, X is —C (CH ₃ ) ₂ —, and a part of Y is a methacryloyloxyethylcarbamoyl group (unsaturated isocyanate residue). A 50% PGMEA solution of photosensitive resin A in which at least a part of Y is a residue of tetrahydrophthalic acid was obtained. The acid value of this photosensitive resin A is 68 mgKOH /
g.

(Example 2) Instead of tetrahydrophthalic anhydride in Example 1, pyromellitic dianhydride (42.
In the same manner as in Example 1 except that 6 g) was used, in the general formula (1), R ₁ and R ₂ are both hydrogen atoms, X is —C (CH ₃ ) ₂ —, and a part of Y is used. Is a methacryloyloxyethylcarbamoyl group, and 50 of the photosensitive resin A in which at least a part of Y is a residue of pyromellitic acid.
% PGMEA solution was obtained. The acid value of this photosensitive resin A is 1
It was 90 mgKOH / g.

Example 3 Instead of tetrahydrophthalic anhydride in Example 1, trimellitic anhydride (38.
4g) was used in the same manner as in Example 1 except that in the general formula (1), R ₁ and R ₂ are both hydrogen atoms, X is —C (CH ₃ ) ₂ —, and a part of Y is used. Is a methacryloyloxyethylcarbamoyl group, and at least other part of Y is a residue of trimellitic acid.
% PGMEA solution was obtained. The acid value of this photosensitive resin A is 1
It was 30 mg KOH / g.

(Preparation of the Composition) The PGMEA solutions of the photosensitive resin A obtained in Examples 1 to 3 and the epoxy compound B having at least one epoxy group in the molecule.
In some cases, the unsaturated compound C, the initiator, and the organic solvent for adjusting the concentration were mixed in the following proportions to prepare a solder resist solution.

(Example 4) 50% PGMEA solution of Example 1 45 parts Novolac type epoxy resin EOCN-4400 (manufactured by Nippon Kayaku Co., Ltd.) 5 parts Initiator Darocur 4265 (manufactured by Ciba Geigy) 1 part Methyl isobutyl ketone 5 parts

(Example 5) 50% PGMEA solution of Example 2 15 parts Novolac type epoxy resin EOCN-4400 (manufactured by Nippon Kayaku Co., Ltd.) 5 parts Initiator Darocur 4265 (manufactured by Ciba Geigy) 1 part Methyl isobutyl ketone 5 parts

(Example 6) 50% PGMEA solution of Example 3 22 parts Novolac type epoxy resin EOCN-4400 (manufactured by Nippon Kayaku Co., Ltd.) 5 parts Initiator Darocur 4265 (manufactured by Ciba Geigy) 1 part Methyl isobutyl ketone 5 parts

(Example 7) 50% PGMEA solution of Example 1 45 parts Novolac type epoxy resin EOCN-4400 (manufactured by Nippon Kayaku Co., Ltd.) 5 parts Monohydroxyethyl acrylate phthalate (Aronix M- as unsaturated compound C) 5400, manufactured by Toagosei Co., Ltd.) 5 parts Initiator Darocur 4265 (manufactured by Ciba Geigy) 1 part Methyl isobutyl ketone 5 parts

Comparative Example For comparison, the following photosensitive resin composition was prepared using a photosensitive resin conventionally known for alkaline development. The photosensitive resin D used in this comparative example is a photopolymerizable unsaturated compound obtained by reacting an acrylate of a bisphenol A type epoxy resin with an acid anhydride (see JP-A-5-339356). 50% methyl isobutyl ketone solution of photosensitive resin D 20 parts Novolac type epoxy resin EOCN-4400 (manufactured by Nippon Kayaku Co., Ltd.) 5 parts Initiator Darocur 4265 (manufactured by Ciba Geigy) 1 part Methyl isobutyl ketone 5 parts

(Test Example) Each composition of Examples 4 to 7 and the composition of Comparative Example were evaluated as a solder resist. Approximately 50μ of each of the above compositions on a copper-clad glass epoxy board that has been degreased
500 mJ / cm ² through a photomask on which a pattern with a line width of 50 μm is formed by applying a film having a thickness of m and drying.
And the contact exposure. Next, it was developed with a 1% aqueous solution of sodium carbonate at 30 ° C. for 1 minute to remove the unexposed portion. Then put in a drying oven at 150 ° C for 1
Post-baked for a time.

Each of the obtained samples was evaluated for heat resistance, substrate adhesion, developability and storage stability as follows. Heat resistance: The post-baked sample was put in an oven at 250 ° C. for 2 hours, and the state of the film was observed. The evaluation results are indicated by ◯ when there is no abnormality, by Δ when slightly deformed, and by x when cracked, peeled or colored. Substrate adhesion: at least 10 for post-baked samples
A cross-cut was inserted so as to make 0 grids, and a peeling test using a cellophane tape was performed. The evaluation results are shown by ◯ when there is no peeling at all and by x when peeling is observed even a little. Developability: After exposure, the sample was developed with the above-mentioned developing solution and was developed satisfactorily. When the unexposed part was not dissolved or the exposed part was dissolved, it was evaluated as x. Storage stability: The samples of each Example and Comparative Example were stored as a solvent solution at 40 ° C. Those that could form a film without gelation for 1 week or more were evaluated as ◯, and those that gelled within 1 week were evaluated as x. The results are shown in Table 1.

[0057]

[Table 1]

As is clear from Table 1 above, Example 4
Each of the samples of Example 7 satisfied the evaluation criteria in terms of heat resistance, substrate adhesion, developability and storage stability. On the other hand, the sample of Comparative Example using a photosensitive resin containing no unsaturated isocyanate residue had good substrate adhesion and developability, but had a problem in storage stability, and also in heat resistance. It was a little inferior.

[0059]

The photosensitive resin A of the present invention comprises a bisphenol type epoxy resin as a skeleton, an unsaturated isocyanate residue, a photopolymerizable ethylenically unsaturated group, and a polybasic acid anhydride residue. Therefore, it is photopolymerizable, the unexposed portion is alkali-soluble, and the photopolymerized product has high heat resistance. The composition containing the photosensitive resin A, the epoxy compound B, and optionally the unsaturated compound C has good storage stability,
Moreover, the coating film obtained by exposing and heating this is excellent in heat resistance, substrate adhesion, developability, and electrical insulation.
Therefore, the photosensitive resin A of the present invention, and the present composition,
It can be used in a wide range of fields such as solder resists for printed wiring boards, etching resists, interlayer insulating materials, photosensitive adhesives, photosensitive paints, photosensitive materials for screen printing, photosensitive film forming materials, resist inks and the like. In particular, since the composition has good storage stability, it does not need to be prepared each time it is used, and it has an advantage that workability is significantly improved.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03F 7/038 501 G03F 7/038 501

Claims (5)

[Claims] 1. The following general formula (1): (In the formula, R ₁ and R ₂ are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom, and X is —CO—, —SO ₂ —,
_{-CH 2 -, - C (CF} 3) 2 -, - Si (CH 3) 2 -,
_{-C (CH 3) 2 -,} - O- or indicates direct, Y is the residue of a portion of an unsaturated isocyanate residue, other at least partially saturated or unsaturated polybasic acid anhydride And n is an integer of 1 or more). 2. The photosensitive resin described above, wherein a part of the hydroxyl groups of the bisphenol type epoxy acrylate resin is reacted with an unsaturated isocyanate compound having at least one ethylenically unsaturated group, and at least another part thereof is reacted. It is obtained by reacting with a saturated or unsaturated polybasic acid anhydride, wherein the unsaturated isocyanate residue is 0.2 equivalent or more per hydroxyl group of the bisphenol type epoxy acrylate resin, and saturated or unsaturated. The photosensitive resin according to claim 1, wherein the polybasic acid anhydride residue is 0.2 equivalent or more per hydroxyl group of the bisphenol type epoxy acrylate resin. 3. An acid value of 50 mg KOH / g to 200.
Claim 1 or claim 2 within the range of mgKOH / g.
The photosensitive resin according to 1. 4. An alkali-developable photosensitive resin composition containing the photosensitive resin according to any one of claims 1 to 3 and an epoxy compound having at least one epoxy group in a molecule. . 5. The photosensitive resin composition according to claim 4, which contains a compound having at least one ethylenically unsaturated group in the molecule.