TWI403839B - Photohardenability. A thermosetting resin composition and a hardened product thereof - Google Patents

Abstract

The invention provides a light curing and thermal curing resin composition which can not produce the problem of touch drying deterioration, and form curing coating pattern with good chemical tinning resistance, curing material, and printed circuit board formed of solder mask made of the curing material. The light curing and thermal curing resin composition comprises (A) carboxyl containing photosensitive resin obtained from the reaction between the reaction product of phenol phenolic varnish type epoxy resin and unsaturated monocarboxylate and saturated or unsaturated multi-anhydride, (B) other carboxyl containing photosensitive resin except for (A), (C) photopolymerization initiator, (D) diluent, and (E) thermal curing composition, the ratio of (A) and (B) is 50 to 95:50 to 5 (mass ratio). Moreover, (F) curing accelerant is comprised, or barium sulfate and/or silicon dioxide is used as inorganic filler.

Description

Light hardening. Thermosetting resin composition and cured product thereof

The present invention relates to a photocurable ‧ thermosetting resin composition and a cured product thereof, which are suitable for forming a solder resist for a printed circuit board, and more particularly to a photocurable ‧ thermosetting resin composition, and The cured product is excellent in dryness (non-adhesiveness) and electroless tin plating resistance of the coating film, and is excellent in adhesion to various substrates, heat resistance, moisture resistance, chemical resistance, and electrical insulation. A pattern of a hardened film excellent in characteristics. The present invention further relates to a printed circuit board formed by forming a solder resist by a cured product of a related composition.

Now, for some of the printed circuit boards for the people's livelihood and the solder resists for most industrial printed circuit boards, from the viewpoint of high precision and high density, images are formed by ultraviolet light irradiation and development. A liquid developing type solder resist which is hardened (formally hardened) by heat and light irradiation. In addition, liquid-based solder resists using an alkali-developing type using a dilute aqueous alkali solution as a developing liquid have gradually become mainstream because of environmental concerns. In the case of the alkali-developing type solder resist using such a dilute aqueous solution, for example, as described in Patent Document 1, a polybasic acid anhydride is added to a reaction product of a phenolic epoxy compound and an unsaturated monocarboxylic acid, and an active energy ray is added. A liquid photoresist composition comprising a curable resin, a photopolymerization initiator, a diluent, and an epoxy compound is widely used. In the case of using such a composition, by thermally hardening after pattern formation, a three-dimensional mesh structure is formed by an additional reaction of a carboxyl group remaining in the coating film with an epoxy group, whereby adhesion, hardness, and heat resistance can be obtained. A hardened film excellent in properties such as electroless gold plating resistance and electrical insulation.

Incidentally, in the surface treatment of recent printed circuit boards, it is advantageous from the viewpoint of electroless gold plating, safety of a cost surface or a chemical, and the like, and thus electroless tin plating is gradually increasing. However, since electroless tin plating is a substitution plating, there is a problem that copper is hollowed out at the interface between the solder resist and copper, and the solder resist is peeled off. On the other hand, in the case of a solder resist composition excellent in electroless tin plating resistance, in general, there is a problem in the point of dry contact (non-adhesiveness), and after the negative film is exposed to the pseudo-dried coating film and exposed. There is a problem that the negative trace remains on the coating film.

[Patent Document 1] Japanese Patent Publication No. 1-54390 (Scope of Application)

The present invention has been made in view of the problems between the above-described conventional photocurability and thermosetting resin compositions, and its main object is to provide a photocurable ‧ thermosetting resin composition which does not cause finger drying Problems such as deterioration of properties (non-adhesiveness), excellent adhesion to electroless tin plating, adhesion to various substrates similar to conventional solder resist compositions, solder heat resistance, moisture resistance, and chemical resistance A pattern of a cured film excellent in various properties such as electrical insulating properties.

Further, an object of the present invention is to provide a printed circuit board which is obtained by using such a photocurable ‧ thermosetting resin composition, and which has excellent properties as described above, and a solder resist formed by the cured product Made.

In order to achieve the above object, according to the present invention, there is provided a photocurable ‧ thermosetting resin composition comprising (A) a reaction product of a phenol novolak type epoxy resin and an unsaturated monocarboxylic acid, which saturates or does not a carboxyl group-containing photosensitive resin obtained by a reaction of a saturated polybasic acid anhydride, (B) a carboxyl group-containing photosensitive resin other than the carboxyl group-containing photosensitive resin (A), (C) a photopolymerization initiator, (D) a diluent, And (E) a thermosetting compound, wherein the ratio of the component (A) to the component (B) is (A): (B) = 50 to 95: 50 to 5 (mass ratio).

In a suitable aspect, the carboxyl group-containing photosensitive resin (B) other than the carboxyl group-containing photosensitive resin (A) is a reaction product of a cresol novolac type epoxy resin and an unsaturated monocarboxylic acid, and is saturated. Or a carboxyl group-containing photosensitive resin obtained by reacting an unsaturated polybasic acid anhydride.

Further, in a suitable aspect, the photocurable ‧ thermosetting resin composition of the present invention further contains (F) a curing accelerator in addition to the above components, or additionally contains barium sulfate and/or Cerium oxide is used as the (G) inorganic filler.

The photocurable ‧ thermosetting resin composition may be any of a liquid form and a dry film form.

Further, according to the present invention, there is provided a cured product obtained by exposing and developing a film of the photocurable ‧ thermosetting resin composition formed on a substrate, followed by heat treatment after irradiation with active energy rays, or after heat treatment The active energy ray irradiation step or the heat treatment is completed to obtain a printed circuit board by forming a solder resist by the cured material.

The photocurable ‧ thermosetting resin composition of the present invention has a carboxyl group-containing photosensitive resin formulated in combination with (C) a photopolymerization initiator, (D) a diluent, (E) a thermosetting compound, or the like And a carboxyl group-containing photosensitive resin obtained by reacting (A) a reaction product of a phenol novolak type epoxy resin and an unsaturated monocarboxylic acid with a saturated or unsaturated polybasic acid anhydride, and (B) the above-mentioned carboxyl group-containing photosensitive resin Other carboxyl group-containing photosensitive resin other than the resin (A) (in the ratio of (A): (B) = 50 to 95: 50 to 5 (mass ratio)), so that dryness does not occur (non-adhesiveness) The problem of deterioration of electroless tin plating, such as adhesion to various substrates similar to the conventional solder resist composition, solder heat resistance, moisture resistance, chemical resistance, electrical insulation, etc. A hardened material with excellent properties. Therefore, such a photocurability ‧ thermosetting resin composition is most suitable for formation of a solder resist of a printed circuit board.

In order to solve the problem that the conventional photocurability and thermosetting resin composition have poor electroless tin plating resistance, the inventors of the present invention have reviewed the use of a cresol novolak type epoxy resin which is generally used as a photosensitive resin in the past. A reaction product of a saturated monocarboxylic acid, a carboxyl group-containing photosensitive resin obtained by a reaction of a saturated or unsaturated polybasic acid anhydride (hereinafter referred to as a carboxyl group-containing photosensitive resin having a cresol novolac type skeleton), and a phenol having a lower softening point A carboxyl group-containing photosensitive resin (A) obtained by reacting a reaction product of a phenolic epoxy resin and an unsaturated monocarboxylic acid with a saturated or unsaturated polybasic acid anhydride (hereinafter, a carboxyl group-containing photosensitive resin called a phenol novolak type skeleton) ).

As a result, it was confirmed that the electroless tin plating resistance was improved, and the dryness (non-adhesiveness) of the pseudo-dried coating film was deteriorated. Then, the inventors of the present invention have further studied the results, and found that the carboxyl group-containing photosensitive resin (A) of the phenol novolak type skeleton and other carboxyl group-containing photosensitive resin (B), in particular, the cresol novolac type skeleton When the carboxyl group-containing photosensitive resin is used in combination at a ratio of (A):(B)=50 to 95:50 to 5 (mass ratio), the problem of deterioration in dryness of the touch is not caused, and electroless tin plating can be obtained. The hardened film excellent in durability is such that the present invention has been completed.

In other words, the photocurable ○ thermosetting resin composition of the present invention is characterized in that the carboxyl group-containing photosensitive resin (A) containing a phenol novolak type skeleton is 50% of the carboxyl group-containing photosensitive resin (A+B). The ratio of % or more is excellent in electroless tin plating resistance, and on the other hand, the problem of deterioration of adhesion is caused by using other carboxyl group-containing photosensitive resin (B) in combination with a cresol novolac type skeleton. Solved by a carboxyl photosensitive resin. When the carboxyl group-containing photosensitive resin (A) of the phenol novolak type skeleton exceeds 95% of the total carboxyl group-containing photosensitive resin (A+B), the touch drying property (non-adhesive property) is as shown in the examples and the like described later. Getting worse. On the other hand, when the carboxyl group-containing photosensitive resin (A) of the phenol novolak type skeleton is 50% of the total (A+B) of the carboxyl group-containing photosensitive resin, the electroless tin plating resistance is inferior. It is preferable to use a carboxyl group-containing photosensitive resin (A) containing a phenol novolak type skeleton and a carboxyl group-containing photosensitive resin (B) other than the carboxyl group-containing photosensitive resin (B), particularly a cresol novolak type skeleton ( By (A): (B) = 70 to 92: 30 to 8 (mass ratio), it is possible to more reliably obtain both electroless tin plating resistance and finger touch drying property.

Hereinafter, the photocurability ‧ thermosetting resin composition of the present invention will be described in detail.

First, the carboxyl group-containing photosensitive compound (A) of the phenol novolak type skeleton is an epoxy group of the phenol novolac type epoxy resin (a), and the carboxyl group of the unsaturated monocarboxylic acid (b) is subjected to an esterification reaction (full esterification or Partially esterified, preferably fully esterified), the resulting hydroxyl group is further obtained by subjecting a saturated or unsaturated polybasic acid anhydride (c) to an additional reaction, and each reaction system uses a catalyst as described later, and is easily used in a solvent. get on.

Examples of the above-mentioned unsaturated monocarboxylic acid (b) include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, α-cyanocinnamic acid, β-styrylacrylic acid, β-mercaptoacrylic acid, and the like. . Among these, it is preferable that acrylic acid and/or methacrylic acid is preferable in view of the influence on the photoreactivity and the physical properties of the cured product, particularly heat resistance, electrical properties, and moisture absorption resistance. These unsaturated monocarboxylic acids may be used alone or in combination of two or more.

The phenol novolak type epoxy resin (a) is obtained by reacting a reaction product obtained by reacting an unsaturated monocarboxylic acid (b) with a saturated or unsaturated polybasic acid anhydride (c) to obtain a phenol used in the present invention. In the reaction, the polybasic acid anhydride (c) is used in an amount of 20 to 200 mgKOH/g. It is preferably an additional amount of 50 to 120 mgKOH/g). When the acid value of the carboxyl group-containing photosensitive resin is less than 20 mgKOH/g, the solubility in an aqueous alkali solution is deteriorated, and development of the formed coating film with an aqueous alkali solution becomes difficult. On the other hand, when the acid value is higher than 200 mgKOH/g, it is not affected by the conditions of exposure, and development occurs on the surface of the exposed portion, which is not preferable.

The phenol novolak type epoxy resin (a) and the unsaturated group contain an esterification reaction of a monocarboxylic acid (b) and an additional reaction of a polybasic acid anhydride (c), and the presence of an organic solvent to be described later and polymerization of hydroquinone or oxygen In the presence of a inhibiting agent, it is usually carried out at about 50 to 150 °C. In this case, a tertiary amine such as triethylamine or a tertiary ammonium salt such as triethylbenzylammonium chloride or an imidazole compound such as 2-ethyl-4-methylimidazole or a phosphorus compound such as triphenylphosphine may be added as necessary. As a catalyst.

Examples of the polybasic acid anhydride (c) include methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, nadic anhydride, and 3. 6-endo-methylenetetrahydrophthalic anhydride, methyl endomethylenetetrahydrophthalic anhydride, tetrabromophthalic anhydride and other alicyclic dibasic anhydride; succinic anhydride, maleic anhydride, itaconic anhydride An aliphatic or aromatic dibasic anhydride such as octenyl succinic anhydride, penta (dodecenyl) succinic anhydride, phthalic anhydride or trimellitic anhydride; or biphenyltetracarboxylic dianhydride or diphenyl ether tetracarboxylate An aliphatic or aromatic tetrabasic acid dianhydride such as acid dianhydride, butane tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, pyrogallanic anhydride or diphenyl ketone tetracarboxylic dianhydride can be used. One or two or more of these. In particular, alicyclic dibasic anhydrides are particularly preferred.

The carboxyl group-containing photosensitive resin (B) other than the carboxyl group-containing photosensitive resin (A) of the phenol novolak type skeleton has at least one (preferably two or more) carboxyl groups in one molecule. A compound having an ethylenically unsaturated double bond can be used without being limited by a specific one, and a photosensitive resin (any of an oligomer and a polymer) as exemplified below can be suitably used.

(1) an epoxy group of a polyfunctional epoxy compound (a) having at least two epoxy groups in one molecule other than a phenol novolak type epoxy resin, and an unsaturated monocarboxylic acid as described above The carboxyl group of (b) is subjected to an esterification reaction (full esterification or partial esterification, preferably full esterification), and the carboxyl group formed by further reacting the generated hydroxyl group with a saturated or unsaturated polybasic acid anhydride (c) Resin,

(2) A copolymer of an unsaturated carboxylic acid such as (meth)acrylic acid and a compound having an unsaturated double bond such as α-methylstyrene, lower alkyl (meth) acrylate or isobutylene a compound having an ethylenically unsaturated group such as a vinyl group, a propylene group or a (meth) acrylonitrile group, and a reactive group such as an epoxy group or an acid chloride, for example, glycidyl (meth)acrylate, and a carboxyl group-containing photosensitive resin obtained by adding an ethylenically unsaturated group as a side chain,

(3) a copolymer of an epoxy group such as glycidyl (meth)acrylate or α-methylglycidyl (meth)acrylate with a compound having an unsaturated double bond and a compound having an unsaturated double bond, a carboxyl group-containing photosensitive resin obtained by reacting an unsaturated carboxylic acid with a secondary hydroxyl group formed by reacting a saturated or unsaturated polybasic acid anhydride as described above, and

(4) a copolymer of an acid anhydride having an unsaturated double bond such as maleic anhydride or itaconic anhydride and a compound having an unsaturated double bond, and a hydroxyl group such as a hydroxyalkyl (meth)acrylate having an unsaturated double bond The carboxyl group-containing photosensitive resin obtained by the reaction of the compound is not limited by the above.

These carboxyl group-containing photosensitive resins (B) may be used alone or in combination of two or more.

Among the other carboxyl group-containing photosensitive resins (B) other than the carboxyl group-containing photosensitive resin (A) of the phenol novolak type skeleton, the carboxyl group-containing photosensitive resin of the above (1) is particularly preferable. Examples of the polyfunctional epoxy compound (a) having at least two epoxy groups in one molecule other than the phenol novolak type epoxy resin include a cresol novolac type epoxy resin and a bisphenol A type epoxy resin. , brominated epoxy resin, hydrogenated bisphenol A epoxy resin, glycidyl amine epoxy resin, alicyclic epoxy resin, trishydroxyphenylmethane epoxy resin, bisphenol or biphenol Type epoxy resin or such mixtures, bisphenol S type epoxy resin, tetrahydroxyphenylethane type epoxy resin, heterocyclic epoxy resin, diglycidyl diglycolate resin, tetraglycidyl group B Alkane resin, naphthyl group-containing epoxy resin, epoxy resin having dicyclopentadiene skeleton, glycidyl methacrylate copolymerized epoxy resin, cyclohexylmaleimide and glycidyl methacrylate Copolymerized epoxy resin and the like.

Among the carboxyl group-containing photosensitive resins (1), in particular, in the epoxy group of the cresol novolac type epoxy resin, the carboxyl group of the above unsaturated monocarboxylic acid (b) is subjected to esterification reaction (all a carboxyl group-containing photosensitive resin having a cresol novolac type skeleton obtained by reacting a hydroxyl group or a partially esterified group, which is preferably a fully esterified product, and a saturated or unsaturated polybasic acid anhydride (c) It is excellent in drying property, heat resistance, and the like.

The acid value of the carboxyl group-containing photosensitive resin (B) is preferably from 20 to 200 mgKOH/g, preferably from 50 to 120 mgKOH/g. When the acid value is less than 20 mgKOH/g, the solubility in the aqueous alkali solution is deteriorated, and the alkali aqueous solution of the formed coating film causes development to become difficult. On the other hand, when it is more than 200 mgKOH/g, it will not be affected by the conditions of exposure, and development will occur until the surface of the exposed portion, which is not preferable.

As the photopolymerization initiator (C), various conventional photopolymerization initiators which are conventionally known to generate radicals by light irradiation can be used, and examples thereof include benzoin, benzoin methyl ether, and benzoin. Benzoin and benzoin alkyl ethers such as ethyl ether and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylethyl benzene, 2,2-di Ethylidene benzene such as ethoxy-2-phenylethyl benzene or 1,1-dichloroacetamidine; 2-methyl-1-[4-(methylthio)phenyl]-2-? Oleinoaminoacetone-1,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, N,N-dimethylamino B Amino phthalic acid such as benzene; 2-methyl hydrazine, 2-ethyl hydrazine, 2-tert-butyl fluorene, 1-chloroindole and the like; 2,4-dimethyl Thioxanthone such as thioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; acetophenone ketal, benzyl a ketal such as dimethyl ketal; an organic peroxide such as benzammonium peroxide or anisole peroxide; a 2,4,5-triaryl imidazole dimer, riboflavin tetrabutyrate 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzoene a thiol compound such as azole; an organohalogen compound such as 2,4,6-tris-triazine, 2,2,2-tribromoethanol or tribromomethylphenylhydrazine; diphenyl ketone, 4, 4' a diphenyl ketone such as bis diethylaminodiphenyl ketone or a xanthone; a 2,4,6-trimethylbenzimidyldiphenylphosphine oxide. These well-known photopolymerization initiators may be used singly or in the form of a mixture of two or more, and further, N,N-dimethylamino benzoic acid ethyl ester, N,N-dimethylamine may be further added. A photoinitiator such as a tertiary amine such as isoamyl acetyl ester, amyl-4-dimethylamino benzoate, triethylamine or triethanolamine. Further, in order to promote the photoreaction, a titanocene compound such as CGI-784 (manufactured by CIBA-GEIGY Co., Ltd.) which absorbs in the visible light region may be added. Particularly suitable photopolymerization initiators are 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinoaminoacetone-1, 2-benzyl-2-dimethyl Aminoamino-1-(4-morpholinophenyl)-butan-1-one, etc., and not particularly limited by these, as long as it absorbs light in the ultraviolet or visible region, making (meth) propylene The radical polymerization of an unsaturated group such as a mercapto group is not limited to a photopolymerization initiator or a photoinitiator, and may be used singly or in combination. The amount of use is 100 parts by mass (solid content, the same applies hereinafter), and is preferably from 1 to 20 parts by mass, based on 100 parts by mass of the total of the carboxyl group-containing photosensitive resins (A) and (B). appropriate.

As the diluent (D), a photopolymerizable monomer or an organic solvent which is liquid at room temperature (about 20 to 30 ° C) can be used. The purpose of using these diluents is to dissolve the above-described carboxyl group-containing photosensitive resins (A) and (B), and to adjust the composition to a viscosity suitable for various coating methods. Further, the liquid photopolymerizable monomer at room temperature has the purpose of improving the photoreactivity of the composition or the solubility of the aqueous alkali solution. However, when a photopolymerizable monomer which is liquid at room temperature is used in a large amount, the touch drying property of the coating film cannot be obtained, and the characteristics of the coating film tend to deteriorate, so that the carboxyl group-containing photosensitive resin is used. 100 parts by mass or less and 100 parts by mass or less of the total amount of A) and (B) is preferably 50 parts by mass or less, and 10 parts by mass or more is suitable. The organic solvent is not limited by the coating method as long as it can be dried under a predetermined drying condition, that is, it does not adversely affect the dry coating film, and generally, relative to the above-mentioned carboxyl group-containing photosensitive resin. 100 parts by mass of the total amount of (A) and (B) is preferably 200 parts by mass or less, and more preferably 10 parts by mass or more.

The liquid photopolymerizable monomer at room temperature may, for example, be a hydroxyl group-containing acrylate such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, pentaerythritol triacrylate or dipentaerythritol pentaacrylate; Acrylate derivatives such as decylamine acrylate and N-hydroxymethyl methacrylate; water-soluble acrylates such as polyethylene glycol diacrylate and polypropylene glycol diacrylate; trimethylolpropane triacrylate, pentaerythritol IV Polyfunctional polyester acrylates of polyfunctional alcohols such as acrylate and dipentaerythritol hexaacrylate; polyfunctional alcohols such as trimethylolpropane and hydrogenated bisphenol A; or ethylene oxidation of polyfunctional phenols such as bisphenol A and biphenol An acrylate of an additive or a propylene oxide addition; a polyfunctional or monofunctional polyurethane acrylate which is a hydroxy acrylate-containing isocyanate conversion; bisphenol A diglycidyl ether, plus Epoxy acrylates of (meth)acrylic acid addenda of hydrogen bisphenol A diglycidyl ether or phenol novolac epoxy resin, and methacrylates corresponding to the above acrylates, etc. Alone or in combination of two or more.

Further, examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; cellosolve, methyl cellosolve, and butyl cellosolve; Glycol ethers such as carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; Ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol Acetate such as methyl ether acetate; alcohol such as ethanol, propanol, ethylene glycol or propylene glycol; aliphatic hydrocarbon such as octane or decane; petroleum ether, petroleum brain, hydrogenated petroleum brain, solvent oil, etc. The solvent and the like may be used singly or in the form of a mixture of two or more. Such an organic solvent can be used not only in the preparation of the composition, but also in the synthesis of the carboxyl group-containing photosensitive resin (A) and (B), or in order to dilute the reaction solution after the synthesis. Further, in order to adjust the viscosity for coating on the substrate or the carrier film, an organic solvent can be used.

In the photocurable ‧ thermosetting resin composition of the present invention, the thermosetting compound (E) to be blended with the carboxyl group-containing photosensitive resin (A) and (B) is cured by itself. Or by reacting with the carboxyl group of the carboxyl group-containing photosensitive resin (A) and (B) by heat, and reacting with the carboxyl group of the carboxyl group-containing photosensitive resin (A) and (B) An epoxy resin or an oxetane compound having two or more epoxy groups or oxetane groups in one molecule, particularly preferably an epoxy resin.

Specific examples of the epoxy resin include bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol F type epoxy resin, and double Phenol S type epoxy resin, phenolic epoxy resin, phenol novolak type epoxy resin, cresol novolac type epoxy resin, N-glycidyl type epoxy resin, phenolic epoxy resin of bisphenol A, 茬Phenolic epoxy resin, biphenol epoxy resin, chelating epoxy resin, glyoxal epoxy resin, amine based epoxy resin, rubber modified epoxy resin, dicyclopentadiene phenol epoxy Resin, diglycidyl phthalate resin, heterocyclic epoxy resin, tetraglycidyl decyl ethane resin, polyoxyn modified epoxy resin, ε-caprolactone modified epoxy resin, and the like. Further, in order to impart flame retardancy, it is also possible to use an atom such as a halogen or a ruthenium such as chlorine or bromine introduced into the structure. These epoxy resins are thermally cured to improve properties such as adhesion of the cured film, solder heat resistance, and electroless plating resistance. Moreover, it is preferable that the epoxy resin is mixed immediately before the photocurable ‧ thermosetting resin composition is applied to the object to be coated. The light-curing property of the thermosetting resin composition can be prevented from being viscous by mixing immediately before the application of the epoxy resin.

Further, in the photocurable ‧ thermosetting resin composition of the present invention, the epoxy resin is preferably used in a solid or semi-solid state at room temperature, and is preferably insoluble or poorly soluble in the above diluent (D). Epoxy resin is preferred. By using such an epoxy resin, the solid or semi-solid epoxy resin is dispersed in the form of fine particles in the photocurable ‧ thermosetting resin composition before curing. The particle size is preferably such that it does not cause an obstacle to screen printing or the like. In this way, the solid or semi-solid epoxy resin is dispersed in the form of fine particles in the photocurable ‧ thermosetting resin composition before curing, and the photocurable ‧ thermosetting resin composition can be used for a long period of time. good. Examples of the epoxy resin suitable for solid or semi-solid at room temperature include bisphenol S type epoxy resin, phenol novolak type epoxy resin, decanoic acid diglycidyl ester resin, heterocyclic epoxy resin, and the like. A phenol type epoxy resin, a biphenyl type epoxy resin, a tetraglycidyl decyl ethane resin, or the like.

In the photocurable ‧ thermosetting resin composition of the present invention, the thermosetting compound (E) may be used singly or in the form of a mixture of two or more. The amount thereof is preferably from 5 to 80 parts by mass, preferably from 10 to 50 parts by mass, per 100 parts by mass of the total of the carboxyl group-containing photosensitive resins (A) and (B). When the amount is less than 5 parts by mass, the solder heat resistance or the electroless tin plating resistance of the cured product of the thermosetting resin composition may be insufficient. On the other hand, if it exceeds 80 parts by mass, it is used. The characteristics, particularly the electrical insulating properties, in the case of an insulating protective film of a printed circuit board tend to deteriorate.

The photocuring ‧ thermosetting resin composition of the present invention may contain a curing accelerator (F) in order to promote the thermosetting reaction and further improve properties such as adhesion, chemical resistance, and heat resistance.

Specific examples of the hardening accelerator (F) include imidazole and derivatives thereof (for example, manufactured by Shikoku Kasei Kogyo Co., Ltd., 2MZ, 2E4MZ, C11Z, C17Z, 2PZ, 1B2MZ, 2MZ-CN, 2E4MZ- CN, C11Z-CN, 2PZ-CN, 2PHZ-CN, 2MZ-CNS, 2E4MZ-CNS, 2PZ-CNS, 2MZ-AZINE, 2E4MZ-AZINE, C11Z-AZINE, 2MA-OK, 2P4MHZ, 2PHZ, 2P4BHZ, etc.); Amidoxime such as acetamide or benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenyl hydrazine, dicyanodicimide, urea, Polyamines such as urea derivatives, melamine, polybasic hydrazine; such organic acid salts and/or epoxy adducts; amine complexes of boron trifluoride; ethyldiamine-S-triazine, Triazine derivatives such as 2,4-diamino-S-triazine, 2,4-diamino-6-mercapto-S-triazine; trimethylamine, triethanolamine, N,N-di Methyl octylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa(N-methyl)melamine, 2,4,6-tris(dimethylaminophenol), Amines such as tetramethylguanidine and m-aminophenol; polyvinylphenol, polyvinylphenol bromide, phenol novolac, alkylphenol novolac Polyphenols; organic phosphines such as tributylphosphine, triphenylphosphine, tri-2-cyanoethylphosphine; tri-n-butyl (2,5-dihydroxyphenyl)phosphonium bromide, hexamethylenetriazine a sulfonium salt such as ruthenium chloride; a quaternary ammonium salt such as benzyltrimethylammonium chloride or phenyltributylammonium chloride; the above polybasic acid anhydride; diphenylphosphonium tetrafluoroborate, triphenylsulfonium Hexafluoroantimonate, 2,4,6-triphenylthiopyranium hexafluorophosphate, CIBA‧GEIGY, IRGACURE-261, Asahi Chemical Co., Ltd., OPTOMA-SP-170, etc. Catalyst; styrene-maleic anhydride resin; molar reaction of phenyl isocyanate with dimethylamine, or organic polyisocyanate such as toluene diisocyanate, isophorone diisocyanate and dimethyl A hardening accelerator or a curing agent which is conventionally used, such as a molar reaction such as an amine.

These hardening accelerators (F) may be used alone or in combination of two or more. The use of the hardening accelerator (F) is not essential, and it is preferably used in an amount of 0.1 to 25 parts by mass based on 100 parts by mass of the thermosetting compound (E), particularly in the case of promoting the curing. When the amount is more than 25 parts by mass, the sublimation component derived from the cured product is increased, which is not preferable.

In the photocurable ‧ thermosetting resin composition of the present invention, barium sulfate, barium titanate, cerium oxide, fine powdered cerium oxide, amorphous cerium oxide, crystalline cerium oxide, and the like may be further required. The conventional inorganic filler (G) such as molten cerium oxide, spheroidal cerium oxide, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide or mica is used alone or in combination of two or more. These are used for the purpose of suppressing the hardening shrinkage of the coating film, improving the adhesion, hardness, and the like. Among these, it is apparent from the examples described later that it is preferable to use barium sulfate and/or cerium oxide, especially from the viewpoint of electroless tin plating resistance.

The photocurable ‧ thermosetting resin composition of the present invention can be further suitably used in combination with phthalocyanine blue, phthalocyanine green, iodine green, bisazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, etc. Well-known thermal polymerization inhibitors such as coloring agents, hydroquinone, hydroquinone monomethyl ether, tert-butylcatechol, gallic phenol, phenothiazine, fine powder of cerium oxide, organic bentonite, montmorillonite, etc. Conventional tackifiers, polyfluorene-based, fluorine-based, polymer-based antifoaming agents and/or homogenizers, imidazole imparting agents such as imidazoles, thiazoles, and triazoles, and antioxidants, antioxidants, A well-known additive such as a rust preventive agent.

The photocurable ‧ thermosetting resin composition of the present invention having the composition described above is adjusted to a viscosity suitable for the coating method by, for example, dilution with the above organic solvent, as necessary, by screen printing A method such as a curtain coating method, a spray coating method, or a roll coating method is applied to a substrate (for example, a printed circuit board on which a circuit is formed), and is contained in the composition at a temperature of, for example, about 60 to 100 ° C. The organic solvent is volatilized and dried (false drying) to form a non-adhesive coating film.

Thereafter, the obtained coating film (photocurability ‧ thermosetting resin composition layer) is exposed (irradiation of active energy ray). Exposure is by contact (or non-contact), through a patterned mask (negative), selectively by active energy ray exposure, or by direct exposure of a laser direct exposure machine Any of the methods is acceptable.

Further, in the case of exposure by irradiation with an active energy ray, the contact type which is directly in contact with the coating film which is pseudo-dried to the mask is considered to be non-contact type from the viewpoint of handleability, resolution, and the like. The photocurable ‧ thermosetting resin composition of the present invention is excellent in finger-drying property (non-adhesiveness), and therefore, a contact type can be suitably used.

By the above exposure, the exposed portion of the coating film (the portion irradiated with the active energy ray) is hardened. Next, the unexposed portion is developed by a dilute aqueous alkali solution (for example, 0.3 to 3% aqueous sodium carbonate solution) to form a photoresist pattern. Further, it is thermally cured by heating to a temperature of, for example, about 140 to 180 ° C, or irradiated with an active energy ray, and then heated and hardened or heat-hardened, and then irradiated with an active energy ray to be finally hardened (formally hardened) to form an electroless tin plating resistance. A cured film (cured material) excellent in electrical insulating properties, adhesion, solder heat resistance, and chemical resistance.

As the aqueous alkali solution, an aqueous alkali solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium citrate, ammonia or an amine can be used.

Further, as the irradiation light source for performing photohardening, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp or a metal halide lamp is suitably used. In addition, laser light or the like can also be utilized as an active energy ray.

[Examples]

The present invention and the comparative examples are specifically described below, but the present invention is not specifically limited by the following examples. In addition, the so-called "parts" below are all based on quality unless otherwise specified.

Example 1

In the composition shown in Table 1, each component was mixed in a dissolver and uniformly dispersed to obtain a photocurable ‧ thermosetting resin composition. This was applied to the copper through-hole printed wiring board on which the pattern was formed by a screen printing method using a 100-mesh polyester screen so as to have a thickness of 20 to 30 μm. Next, the coating film was dried using a hot air circulating drying oven at 80 ° C for 30 minutes, and the test methods and evaluation methods described later were carried out to test the dryness and developability of the touch.

Then, the negative film having the photoresist pattern was adhered to the coating film, and an ultraviolet ray exposure apparatus (manufactured by ORC Co., Ltd., type HMW-680GW) was irradiated with ultraviolet rays (exposure amount: 300 mJ/cm ² ), and then at 1 wt% of sodium carbonate. The aqueous solution was developed with a spray pressure of 60 seconds and 0.2 MPa. Thereafter, the film was heat-cured in a hot air circulating drying oven at 150 ° C for 60 minutes, and then allowed to cool to room temperature, and then post-exposure with a high-pressure mercury lamp at 1000 mJ/cm ² to prepare a test substrate.

For the obtained test substrate, the test method and the evaluation method described later were tested for solder heat resistance and electroless tin plating resistance. The results are shown in Table 2.

As shown in the above Table 2, when the carboxyl group-containing photosensitive resin containing only the phenol novolak type skeleton was used as the sample No. 1 of the carboxyl group-containing photosensitive resin, the dryness to the touch was poor. On the other hand, in the case of Sample Nos. 5 to 8 in which the content ratio of the carboxyl group-containing photosensitive resin of the phenol novolak type skeleton is less than 50% with respect to the entire carboxyl group-containing photosensitive resin, the electroless tin plating resistance is inferior.

In addition, each test method and evaluation method are as follows.

(1) Dry touch:

The dryness of the touch of the surface of the coated film after drying was evaluated by the following criteria.

○: There is no sticky at all.

△: Slightly sticky.

╳: There is a sticky person.

(2) Imaging

The drying conditions after the formation of the coating film were changed to dry at 80 ° C for 40 minutes to 70 minutes, and the state of removal of the coating film in the unexposed portion after development was visually confirmed. The evaluation criteria are as follows.

○: There is no imaging residue at all.

△: A small amount of filler residue was found on the surface.

╳: There are residual images in the whole area

(3) Solder heat resistance:

A rosin-based flux was applied onto the test substrate, and immersed in a solder bath set at 260 ° C for 30 seconds. After the test substrate was washed with an organic solvent, the test piece was subjected to a peeling test using a cellophane adhesive tape, and was judged by the following criteria.

○: There is no change in appearance.

△: It is considered that there is a discoloration of the hardened coating film.

╳: It is thought that there is a floating coating of the hardened film and a solder intrusion.

(4) Electroless tin plating resistance:

Electroless tin plating was performed on the test substrate according to the procedure described later, and the test substrate was subjected to a change in appearance and a peeling test using a cellophane adhesive tape, and the peeling state of the resist film was evaluated by the following criteria.

○: The appearance did not change, and there was no peeling of the photoresist film at all.

△: There was no change in appearance, and the photoresist film was slightly peeled off.

╳: It was found that the photoresist film floated, and it was considered that there was plating sneak in, and the photoresist film was peeled off in the peeling test.

Electroless tin plating step:

1. Degreasing: The test substrate was immersed in an acidic degreasing liquid (manufactured by Mac Dermid Co., Ltd., Metex L-5B, 20% by volume aqueous solution) at 30 ° C for 3 minutes.

2. Water washing: The test substrate was immersed in running water for 3 minutes.

3. Soft etching: The test substrate was immersed in a 14.3 wt% aqueous ammonium persulfate solution at room temperature for 1 minute.

4. Water washing: The test substrate was immersed in running water for 3 minutes.

5. Acid impregnation: The test substrate was immersed in a 10% by volume aqueous sulfuric acid solution at room temperature for 1 minute.

6. Water washing: The test substrate was immersed in running water for 30 seconds to 1 minute.

7. Electroless tin plating: The test substrate was immersed in a tin plating solution (manufactured by ATOTECH Co., Ltd., Stannatech H plus 73% by volume, SF special acid 6% by volume, SF Tin Solution C5.5% by volume, 70 ° C, pH=1). Stannatech SN correction solution 15.5 vol%, Stannatech additive C 0.125 vol% solution) for 12 minutes.

8. Water washing: The test substrate was immersed in running water for 3 minutes.

Examples 2 to 7 and Comparative Examples 1, 2

The photocurable ‧ thermosetting resin composition was prepared in the same manner as in Example 1 except that the composition shown in Table 3 was used, and the touch drying property, developing property, and solder heat resistance were performed by the above method. Electroless tin plating resistance test. The results are shown in Table 4.

From the results shown in the above Table 4, it is apparent that the cured film formed of the photocurable ‧ thermosetting resin composition of the present invention is characterized by contact drying property, developing property, solder heat resistance, and electroless tin plating resistance. Excellent. On the other hand, in the case of Comparative Examples 1, 2, and 4 in which the carboxyl group-containing photosensitive resin is a carboxyl group-containing photosensitive resin containing no phenol novolak type skeleton, the developing property or the electroless tin plating resistance is inferior, and the carboxyl group-containing photosensitive property is also poor. In the case of Comparative Example 3 in which the resin was a carboxyl group-containing photosensitive resin containing only a phenol novolak type skeleton, the dryness to the touch was poor. Further, when Examples 3 and 4 are compared with Example 5, it is apparent that in Examples 3 and 4 using barium sulfate or cerium oxide, electroless tin plating was used as compared with Example 5 using talc as the inorganic filler. Since the resistance is excellent, it is understood that the inorganic filler is preferably barium sulfate or cerium oxide.

Claims (7)

A photohardenability. A thermosetting resin composition characterized by containing the following components (A) to (E), and (A) a reaction product of a phenol novolak type epoxy resin and an unsaturated monocarboxylic acid to make a saturated or unsaturated polybasic base a carboxyl group-containing photosensitive resin obtained by an acid anhydride reaction; (B) a carboxyl group-containing photosensitive resin having at least one or more carboxyl groups and an ethylenically unsaturated double bond in one molecule, and the carboxyl group-containing photosensitive resin is selected from the group consisting of In the group consisting of the following (1) and (2), (1) a part of a copolymer of an unsaturated carboxylic acid and a compound having an unsaturated double bond, having an ethylenically unsaturated group and a carboxyl group Reaction of a compound having a reactive reactive group, and a carboxyl group-containing photosensitive resin obtained by adding an ethylenically unsaturated group as a side chain, (2) an acid anhydride having an unsaturated double bond and having an unsaturated double a copolymer of a bond compound, a carboxyl group-containing photosensitive resin obtained by reacting a compound having a hydroxyl group and an unsaturated double bond; (C) a photopolymerization initiator; (D) a diluent; and (E) a thermosetting compound And the ratio of the component (A) to the component (B) is (A): (B) = 70 to 92: 30 to 8 (mass ratio) And an acid value of the component (A) and the component (B) are both in the range of 50 ~ 120mgKOH / g of. Such as the application of patent scope 1 of the light hardenability. Thermosetting resin In the composition, the photopolymerization initiator (C) is added in an amount of from 0.5 to 30 parts by mass based on 100 parts by mass of the total of the carboxyl group-containing photosensitive resins (A) and (B). The compounding amount of the agent (D) is 100 parts by mass or less, and the amount of the thermosetting compound (E) is 5 to 80 parts by mass. Such as the application of patent scope 1 of the light hardenability. The thermosetting resin composition further contains (F) a curing accelerator. Such as the application of patent scope 1 of the light hardenability. The thermosetting resin composition further contains barium sulfate and/or cerium oxide as the (G) inorganic filler. Photocuring properties as claimed in any of claims 1 to 4. A thermosetting resin composition which can be used for a solder resist for electroless tin plating. A cured product characterized by photohardenability of any one of claims 1 to 5 which will be formed on a substrate. After the film of the thermosetting resin composition is exposed and developed, it is obtained by heat treatment after irradiation with active energy rays, or active energy ray irradiation step after heat treatment, or heat treatment. A printed circuit board characterized by the photohardenability of any one of claims 1 to 5. The cured product of the thermosetting resin composition is formed into a solder resist.