JP2000284477A - Photosensitive thermosetting resin composition and soldering resist pattern forming method using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photosensitive thermosetting resin composition excellent in non-adhesivity to fingers during handling, photosetting, development and thermosetting after drying, being applicable to a horizontal drying process as a thin sheet and useful as a liquid photoresist adaptable to SMT(surface mounting technique) and capable of forming a soldering resist film excellent in resistance to the heat of soldering, chemical resistance, adhesion, electric insulating properties, electrical characteristics under humidification, plating resistance, hot tack resistance particularly after drying and resistance to electroless gold plating. SOLUTION: The photosensitive thermosetting resin composition contains (A) a resin curable with an active energy radiation and obtained by allowing (a) a carboxyl-containing (meth)acrylic copolymer resin to react with (b) an alicyclic epoxy-containing unsaturated compound, (B) a resin curable with an active energy radiation having two or more unsaturated groups in one molecule and also having a cyclic skeleton, (C) a diluent, (D) a photopolymerization initiator, (E) a potential set adhesion imparting agent and (F) an epoxy compound as essential components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel photosensitive thermosetting resin composition and a method for forming a solder resist pattern using the same, and more particularly, to the manufacture of printed wiring boards, precision metal working, glass and stone. The present invention relates to a photosensitive thermosetting resin composition which is used for etching of plastics, a material for plastic relief, a member for flat panel display (hereinafter referred to as FPD), a coating protective film and the like, and particularly useful as a solder resist for printed wiring boards.

[0002]

2. Description of the Related Art Printed wiring boards have been used to incorporate electronic components in a compact manner. Printed wiring boards
Generally, copper foil bonded to a laminate is etched according to circuit wiring, and electronic components are arranged at predetermined locations and soldered. The solder resist is used as a protective film of a circuit when soldering an electronic component to such a printed wiring board, and is formed on the entire surface of the circuit conductor except for a portion to be soldered. Such a coating prevents solder from adhering to unnecessary parts during soldering and also prevents the circuit conductors from being directly exposed to air and corroded by oxidation or moisture. Further, it functions as a permanent protective film of the circuit board. Therefore, various properties such as adhesion, electrical insulation, solder heat resistance, solvent resistance, alkali resistance, acid resistance, and plating resistance are required.

Conventionally, such a solder resist has been formed by pattern printing on a substrate by screen printing and curing by ultraviolet light or heat. These solder resists are, for example, a composition cured by heat in JP-B-51-14044, and cured with an active energy ray such as ultraviolet rays in JP-B-61-48800, assuming that productivity is emphasized. A composition is disclosed. However, in recent years, printed wiring boards have become finer (finer) to achieve higher densities,
As the number of layers is increased and the number of boards is increased, the tempo is improved at a remarkable tempo, and the mounting method is further shifted to the surface mounting technology (SMT). Solder resists also have high resolution, high precision,
The demand for high reliability has increased, and the screen printing method has been shifted to the liquid photoresist method for both commercial and industrial substrates. For example, JP-A-61-243869, JP-A-7-50473, and JP-B-7-17737 disclose:
A liquid solder that can be developed with a dilute alkaline aqueous solution that has excellent heat and chemical resistance, using a reaction product obtained by reacting a novolak type epoxy resin with an unsaturated monocarboxylic acid and further adding a polybasic acid anhydride as a base polymer. A resist composition is shown.

[0004]

However, in order to make the above solder resist composition soluble in an alkali developer, a polybasic anhydride is reacted with a reaction product of a novolak type epoxy resin and an unsaturated monocarboxylic acid. Let me. As a result, depending on the combination with the epoxy resin or epoxy resin curing agent, which is a thermosetting component used to obtain the characteristics as a solder resist, as well as lowering the electrical characteristics due to the effect of the generated carboxyl group, the resist Thermal curing proceeds during drying after coating, which may cause development failure, electric corrosion, and discoloration of the copper foil surface. If the amount of the epoxy resin or epoxy curing agent is reduced in order to suppress this effect, there are problems such as inferior heat resistance and adhesion of the cured coating film. Furthermore, the curability by ultraviolet rays is slow, the exposure time is long, and sufficient heat resistance has not yet been obtained.

[0005] In view of the impact on environmental pollution today,
Also for a printed wiring board, a method of cleaning a flux residue after soldering is required. In order to solve this problem, the flux used is changed from solvent cleaning type to water cleaning type.
Furthermore, it has shifted to a non-cleaning type. Many of these water-washing and non-washing fluxes have strong activity,
A problem has arisen in the solder heat resistance of the solder resist. . Furthermore, with the shift of technology to surface mounting in recent years, anti-rust treatment and electroless gold plating are performed to prevent oxidation of printed wiring boards, and thick electroless gold plating is used for bonding and the like. For example, the adhesion between the solder resist and the substrate is reduced, and the solder resist is peeled off.

In order to solve the above problems, JP-A-10-20493 discloses a reaction product of an acid group-containing acrylic copolymer resin and an alicyclic epoxy group-containing unsaturated compound, a novolak type epoxy resin. Discloses a solder resist composition comprising an acid adduct to an esterified product of No. 1, a diluent, a photopolymerization initiator, a curing adhesion promoter, and the like. However, since this solder resist has an acid group in both an acid group-containing acrylic copolymer resin and an acid adduct to an esterified product of a novolak type epoxy resin, it causes a decrease in development resistance and resistance to a plating solution, Insufficient resistance to electroless gold plating. Further, in the above composition,
There were problems such as warpage during pre-drying due to thinning of the printed wiring board, sticking between substrates due to the wind of the dryer, and sticking to the bars of a horizontal rack, and were not suitable for batch-type mass production.

Accordingly, an object of the present invention is to provide a photosensitive thermosetting resin composition which does not have the above-mentioned various problems and is excellent in workability and coating film properties. More specific objects of the present invention are required for the solder resist, coating properties, drying properties, dryness to the touch after drying, hot tack free properties, photocurability, developability, thermosetting properties, pot life A photosensitive thermosetting resin composition that excels in shelf life and other properties, can be dried horizontally on thin plates, can produce solder resist on printed wiring boards in a short time, and is useful as a liquid photoresist that can be developed with a weak alkaline aqueous solution. To provide things. More specific objects of the present invention are solder heat resistance, solvent resistance, chemical resistance, adhesion, electric insulation, electric corrosion resistance, electric properties under humidification, plating resistance, and adhesion on rust-proof substrates. In particular, it is intended to provide a photosensitive thermosetting resin composition useful as a liquid photoresist capable of forming a solder resist film excellent in hot tack-free property after drying and electroless gold plating resistance and capable of coping with SMT. is there.

[0008]

According to the present invention, there is provided, according to the present invention, (A) a (a) carboxyl group-containing (meth) acrylic copolymer resin and (b) an alicyclic epoxy group-containing resin. Active energy ray-curable resin obtained by reaction with unsaturated compound, (B) Active energy ray-curable resin having two or more unsaturated groups in one molecule and having a cyclic skeleton, (C) diluent , (D) a photopolymerization initiator, (E) a latent curing adhesion-imparting agent, and (F) an epoxy compound, which are essential components, have high sensitivity and high resolution, and further have dryness to the touch after drying. Also provided is a photosensitive thermosetting resin composition which is excellent in hot tack-free property and can provide a solder resist film excellent in electroless gold plating resistance.

In a preferred embodiment, the active energy ray-curable resin (A) has an acid value of 50 to 150 mg KOH.
/ G, and the active energy ray-curable resin (B) comprises (c) a novolak type epoxy compound and (d)
A photosensitive prepolymer (B-1), which is an all-esterified epoxy group formed by an esterification reaction with an unsaturated carboxylic acid, and (e) a diisocyanate and (f) 1
From a photosensitive prepolymer (B-2) obtained by reacting a reaction product with a (meth) acrylate having one hydroxyl group in the molecule with a secondary hydroxyl group of the photosensitive prepolymer (B-1). At least one selected from the group consisting of the components (A) and (B) in a mixing ratio of 100: 2
100: 50 (by weight).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The photosensitive thermosetting resin composition according to the present invention comprises (A) (a) a (meth) acrylic copolymer resin containing a carboxyl group and (b) an unsaturated alicyclic epoxy group-containing unsaturated resin. An active energy ray-curable resin obtained by a reaction with a compound and (B) an active energy ray-curable resin having two or more unsaturated groups in one molecule and having a cyclic skeleton are contained in combination. Features. In the active energy ray-curable resin (A), a chemical bond generated by a chemical reaction between an acid group of the (meth) acrylic copolymer resin and an alicyclic epoxy group is a bond having a relatively large steric hindrance. Since a film formed from the composition of the present invention containing such an active energy ray-curable resin (A) is chemically stable to a hydrolysis promoting substance (for example, water, seawater, etc.), A remarkable effect of excellent durability such as water resistance can be obtained. Further, since such an active energy ray-curable resin (A) contains a large number of hydrophobic groups, an effect that the active energy ray-curable resin composition containing the resin is less likely to absorb moisture can be obtained.

More specifically, the active energy ray-curable resin (A) used in the composition of the present invention has a higher Tg than that of a novolak-type epoxy-modified resin, and the resulting coating film has a dry-to-touch property. It has the advantage of excellent workability due to its good properties, but on the other hand, the coating film obtained by radical polymerization of the unsaturated groups of the resin is rigid, and is considered to contain the stress in the coating film. However, when the active energy ray-curable resin (A) is used alone, there is a problem that adhesion such as electroless gold plating resistance is poor. Therefore, the composition of the present invention comprises an active energy ray-curable resin (a) obtained by reacting (a) a carboxyl group-containing (meth) acrylic copolymer resin with (b) an alicyclic epoxy group-containing unsaturated compound ( The active energy ray-curable resin (B) having a cyclic skeleton having no acid group is used in combination with the active energy ray-curable resin (B) having a cyclic skeleton having no acid group. The combined use of (1) and (2) alleviates the rigidity of the coating film and makes it possible to improve the adhesion of the coating film such as electroless gold plating resistance. That is, the photosensitive thermosetting resin composition of the present invention uses the specific active energy ray-curable resins (A) and (B) described above in combination, and combines the active energy ray-curable resins (B). Is a resin containing an unsaturated group having a cyclic skeleton and further containing no acid group, and is completely cured by heat and / or light after coating, drying, exposing and developing the composition. Thus, it is possible to form a solder resist pattern for a printed wiring board which is excellent in various desired properties.

Hereinafter, each component of the photosensitive thermosetting resin composition of the present invention will be described. The active energy ray-curable resin (A) used in the present invention is obtained by reacting (a) a carboxyl group-containing (meth) acrylic copolymer resin with (b) an alicyclic epoxy group-containing unsaturated compound. .
The carboxyl group-containing (meth) acrylic copolymer resin (a) is composed of (meth) acrylic acid ester and 1
And a compound having at least one carboxyl group. Examples of the (meth) acrylate constituting the copolymer resin (a) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, and hexyl. (Meth) acrylic acid alkyl esters such as (meth) acrylate, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate,
Hydroxy group-containing (meth) acrylates such as hydroxybutyl (meth) acrylate and caprolactone-modified 2-hydroxyethyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, isooctyloxydiethylene glycol (meth) Acrylate,
Glycol-modified (meth) acrylates such as phenoxytriethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, and methoxypolyethylene glycol (meth) acrylate. In this specification, the term “(meth) acrylate” is a general term for acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

Compounds having one unsaturated group and at least one carboxyl group in one molecule include acrylic acid, methacrylic acid, and modified unsaturated compounds having a chain extended between the unsaturated group and the carboxylic acid. Monocarboxylic acids, for example, β-carboxyethyl (meth) acrylate, 2-acryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2-acryloyloxyethyl hexahydrophthalic acid, lactone-modified unsaturated esters having an ester bond Monocarboxylic acids, modified unsaturated monocarboxylic acids having an ether bond, and those containing two or more carboxyl groups in the molecule, such as maleic acid, may be mentioned. These may be used alone or as a mixture of two or more.

Alicyclic epoxy group-containing unsaturated compound (b)
May be a compound having one radically polymerizable unsaturated group and an alicyclic epoxy group in one molecule, and examples thereof include compounds represented by the following general formulas (1) to (13). .

Embedded image In each formula, R ¹ is a hydrogen atom or a methyl group, and R ² has 1 to 1 carbon atoms.
An alkylene group of 10, R ³ represents a hydrocarbon group having 1 to 10 carbon atoms, and k represents 0 or an integer of 1 to 10. Even if these alicyclic epoxy group-containing unsaturated compounds (b) are used alone,
Mixtures of more than one species may be used. Of these,
3,4-Epoxycyclohexylmethyl (meth) acrylate is preferred. The addition amount of the alicyclic epoxy group-containing unsaturated compound to the carboxyl group-containing (meth) acrylic copolymer resin (a) is 5 to 50 with respect to the carboxylic acid equivalent of the active energy ray-curable resin (A). It is desirable to be in the range of equivalent%. If the addition amount is less than 5%, the resulting composition has poor light (ultraviolet) curability, and the physical properties of the cured film are undesirably reduced. On the other hand, if the added amount exceeds 50%, the storage stability of the resin is undesirably deteriorated.

The active energy ray-curable resin (A) thus obtained has an acid value of 50 to 150 mg KOH.
/ G. This acid value is 50m
If it is less than gKOH / g, it is difficult to remove unexposed portions with a weak alkaline aqueous solution, while if it exceeds 150 mgKOH / g, there are problems such as poor water resistance and electrical properties of the cured film. Also, active energy ray-curable resin (A)
Is preferably a compound having a weight average molecular weight in the range of 5,000 to 100,000. 5,000 weight average molecular weight
When the weight average molecular weight is less than 100,000, the developing property and the storage stability are remarkably deteriorated.

The preferred active energy ray-curable resin (A) used in the present invention is commercially available from Daicel Chemical Industries, Ltd. under the trade name of Cyclomer PCA series, and is used in the present invention. be able to. For example, ACA-200 has a molecular weight of 15,000, a resin acid value of 118 mg KOH / g, and an ACA-25.
0 is molecular weight 18,000, resin acid value 60 mgKOH / g
It is.

The photosensitive prepolymer (B-1) used as the active energy ray-curable resin (B) is an epoxy group formed by an esterification reaction between (c) a novolak type epoxy compound and (d) an unsaturated carboxylic acid. Are all esterified products. Examples of the novolak type epoxy compound (c) include YDCN-701 and YDCN manufactured by Toto Kasei Co., Ltd.
-704; N-66 manufactured by Dainippon Ink and Chemicals, Inc.
5, N-680, N-695; EO manufactured by Nippon Kayaku Co., Ltd.
CN-102, EOCN-104; ECN-265, ECN-293, ECN-285, manufactured by Asahi Kasei Corporation
Cresol novolak type epoxy resin such as ECN-299, YDPN-638, YDP manufactured by Toto Kasei Co., Ltd.
N-602; DEN-4 manufactured by Dow Chemical Japan Co., Ltd.
31, DEN-438, DEN-439; EPN-1138, E manufactured by Ciba Specialty Chemicals Co., Ltd.
PN-1235, EPN-1299; phenol novolak type epoxy resins such as N-730 and N-770 manufactured by Dainippon Ink and Chemicals, Inc .; Further, a part of the novolak type epoxy resin is, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin,
It can be replaced with epoxy compounds such as bisphenol S type epoxy resin, biphenyl type epoxy resin, bixylenol type epoxy resin, trishydroxyphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, alicyclic epoxy resin, etc. It is particularly preferable to use a phenol novolak type epoxy compound as a solder resist for a wiring board.

Next, as the unsaturated monocarboxylic acid (d), acrylic acid, methacrylic acid, β-styrylacrylic acid, β-furfurylacrylic acid, crotonic acid, α-
Half-esters of cyanocinnamic acid, cinnamic acid, etc., and saturated or unsaturated dibasic anhydrides and (meth) acrylates having one hydroxyl group in one molecule, or unsaturated esters of saturated or unsaturated dibasic acids. Half esters with saturated monoglycidyl compounds such as phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, maleic acid, succinic acid, itaconic acid, chlorendic acid, methylhexahydrophthalic acid, methylendomethylenetetrahydrophthalic acid and methyltetrahydro Saturated or unsaturated dibasic acid anhydrides such as phthalic acid and hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, polyethylene glycol monoacrylate, glycerin acrylate, trimethylolpropane diacrylate, pentaerythrene Litol triacrylate, dipentaerythritol pentaacrylate and triglycidyl isocyanurate diacrylate or methacrylates corresponding to the above acrylates, or the above-mentioned saturated or unsaturated dibasic acid and glycidyl (meth) acrylate in an equimolar ratio by a conventional method. The half-ester or the like obtained by the reaction is used alone or in combination of two or more. Among them, acrylic acid is preferred from the viewpoint of photoreactivity.

The photosensitive prepolymer (B-2) used as the active energy ray-curable resin (B) includes (e) a diisocyanate and (f) a (meth) acrylate having one hydroxyl group in one molecule. Is a reaction product obtained by reacting the reaction product of the above with the secondary hydroxyl group of the photosensitive prepolymer (B-1). (E) Diisocyanates include tolylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate,
Diphenylmethane diisocyanate, toluidine diisocyanate, lysine diisocyanate and the like are used.

Next, (meth) acrylates having one hydroxyl group in one molecule (f) include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, polyethylene glycol monoacrylate, glycerin diacrylate, and the like.
Trimethylolpropane diacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, diacrylate of tris (hydroxyethyl) isocyanate or methacrylate corresponding to the above acrylate is used, and hydroxyethyl acrylate or pentaerythritol triacrylate is particularly preferred.

The compounding ratio of the components (A) and (B) used in the present invention is 100: 2 to 100: 50.
(By weight). If the compounding ratio of the component (B) is less than the above range, the rigidity of the component (A) cannot be sufficiently reduced, and the electroless gold plating resistance is not sufficient. On the other hand, if the compounding ratio of the component (B) exceeds the above range, the dryness of the coating film after drying becomes poor, which is not preferable.

The diluent (C) used in the present invention includes a photopolymerizable monomer and / or an organic solvent. Representative photopolymerizable monomers include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxybutyl acrylate;
Mono- or diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol and propylene glycol; N, N-
Acrylamides such as dimethylacrylamide and N-methylolacrylamide; aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate; hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, tris-
Polyhydric alcohols such as hydroxyethyl isocyanurate or polyhydric acrylates of these ethylene oxide or propylene oxide adducts; phenoxy acrylates, bisphenol A diacrylates, and acrylates of these phenols such as ethylene oxide or propylene oxide adducts Acrylates of glycidyl ethers such as glycerin diglycidyl ether and trimethylolpropane triglycidyl ether; melamine acrylate; and / or methacrylates corresponding to the above acrylates.

On the other hand, organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene Glycol ethers such as glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monoethyl ether, and triethylene glycol monoethyl ether; ethyl acetate;
Esters such as butyl acetate, cellosolve acetate, diethylene glycol monoethyl ether acetate and esterified products of the above glycol ethers; alcohols such as ethanol, propanol, ethylene glycol and propylene glycol; aliphatic hydrocarbons such as octane and decane; Examples include petroleum solvents such as ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

The diluent (C) as described above is used alone or as a mixture of two or more kinds, and a preferable range of the amount is based on 100 parts by weight of the active energy ray-curable resin (A). 20 to 300 parts by weight. The purpose of use of the diluent is, in the case of a photopolymerizable monomer, not only to make it easy to apply, but also to dilute the active energy ray-curable resin to enhance photopolymerizability, while using an organic solvent. This is because in the case of (1), the film is formed by drying. Therefore, depending on the diluent to be used, either a contact type or a non-contact type in which a photomask is brought into contact with a coating film is used.

Representative examples of the photopolymerization initiator (D) used in the present invention include benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether, and benzoin n-butyl ether. Benzoins such as benzoins; benzoin alkyl ethers; benzophenones such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone and 4,4'-bisdiethylaminobenzophenone; acetophenone and 2,2-dimethoxy -2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl - [4- (methylthio) phenyl]
Acetophenones such as -2-morpholino-1-propanone and N, N-dimethylaminoacetophenone;
Thioxanthones such as 4-dimethylthiosanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylthioxanthone; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone , 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone and other anthraquinones; acetophenone dimethyl ketal, benzyl dimethyl ketal and other ketals; ethyl-4
Benzoic acid esters such as dimethylaminobenzoate, 2- (dimethylamino) ethylbenzoate, and p-dimethylbenzoic acid ethyl ester; phenyldisulfide 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, tetra Methylthiuram disulfide and the like. These photopolymerization initiators can be used alone or in combination of two or more.

The preferred range of the amount of the photopolymerization initiator (D) used is 0.05 to 30 parts by weight based on 100 parts by weight of the active energy ray-curable resins (A) and (B). Further, a photo-promoter can be used in combination for the purpose of accelerating the photo-polymerization reaction by the photo-polymerization initiator described above. For example, known photosensitizations such as tertiary amines such as triethylamine, triethanolamine and 2-dimethylaminoethanol, alkylphosphines represented by triphenylphosphine, and thiols represented by β-thioglycol. Agents can be mentioned.

Next, as the latent curing adhesion promoter (E), melamine, ethyldiamino-S-triazine, 2,2
4-diamino-S-triazine, 2,4-diamino-6
S- such as -tolyl-S-triazine, 2,4-diamino-6-xylyl-S-triazine and derivatives thereof
Triazine compounds; guanamine, acetoguanamine, benzoguanamine, 3,9-bis [2- (3,5-diamino-2,4,6-triazaphenyl) ethyl] -2,
Guanamines such as 4,8,10-tetraoxaspiro [5.5] undecane; 2M manufactured by Shikoku Chemical Industry Co., Ltd.
Z, 2E4MZ, C11Z, C17Z, 2PZ, 1B2
HZ, 2MZ-CN, 2E4MZ-CN, C11Z-C
N, 2PZ-CN, 2P11Z-CN, 2MZ-CN
S, 2E4MZ-CNS, 2PZ-CNS, 2MZ-A
ZINE, 2E4MZ-AZINE, C11Z-AZI
NE, 2MA-OK, 2P4MHZ, 2PHZ, 2P4
Imidazole such as BHZ and derivatives thereof; diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, cyclohexylamine, m-xylylenediamine, 4,4′-diamino-3,3′diethyldiphenylmethane, diethylenetriamine, tetraethylenepentamine, Polyamines such as N-aminoethylpiverazine, isophoronediamine, dicyandiamide, urea, urea derivatives, polybasic hydrazides, their organic acid salts and / or epoxy adducts; boron trifluoride amine complexes; trimethylamine, triethanolamine , N, N-dimethyloctylamine, N, N-dimethylaniline, N-benzyldimethylamine, pyridine,
Tertiary amines such as N-methylpyridine, N-methylmorpholine, hexamethoxymethylmelamine, 2,4,6-tris (dimethylaminophenol), N-cyclohexyldimethylamine, tetramethylguanidine, m-aminophenol; tributyl Organic phosphines such as phosphine, triphenylphosphine and tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide and hexadecyltributylphosphonium chloride; benzyltrimethylammonium chloride and phenyl Quaternary ammonium salts such as tributylammonium chloride and benzyltrimethylammonium bromide; diphenyliodonium tetrafluoroboroate, trif Photocationic polymerization catalysts such as nilsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyrylium hexafluorophosphate, Irgacure 261 manufactured by Ciba Specialty Chemicals Co., Ltd .; styrene-maleic acid resin, silane coupling agent In particular, an S-triazine compound is preferably used from the viewpoint of improving adhesion, adhesion, and electroless gold plating resistance. The curing adhesion imparting agent (E) as described above can be used alone or in combination of two or more. A preferable range of the amount is 0.05 to 100 parts by weight of the active energy ray-curable resin (A).
１５15 parts by weight.

Next, as the epoxy compound (F), a known epoxy compound can be used regardless of whether it is solid or liquid. Specific epoxy compounds include the novolak type epoxy compounds mentioned as the component (c);
Bisphenol S-type epoxy compounds such as BPS-200 manufactured by Nippon Kayaku Co., Ltd., EPX-30 manufactured by AC R Co., Ltd., and Epicron EXA-1514 manufactured by Dainippon Ink & Chemicals, Inc .; Nippon Oil & Fats Co., Ltd. Diglycidyl phthalate resin such as Blemmer DGT; heterocyclic epoxy compounds such as TEPIC manufactured by Nissan Chemical Co., Ltd., and Araldite PT810 manufactured by Ciba Specialty Chemicals; YX-4000 manufactured by Yuka Shell Epoxy Co., Ltd. Bixylenol type epoxy compound; YL-60 manufactured by Yuka Shell Epoxy Co., Ltd.
Biphenol type epoxy compound such as 56; Tetraglycidyl xylenoylethane compound such as ZX-1063 manufactured by Toto Kasei Co., Ltd .; EPX- manufactured by Asahi Kasei Kogyo Co., Ltd.
8001, EPX-8002, EPPX-8060, E
Novolak type epoxy compound of bisphenol A such as PPX-8061, Epicron N-880 manufactured by Dainippon Ink and Chemicals, Inc .; EPX-4 manufactured by Asahi Denka Kogyo KK
Chelate type epoxy compounds such as 9-69 and EPX-49-30; glyoxal type epoxy compounds such as YDG-414 manufactured by Toto Kasei Co., Ltd .; Y manufactured by Toto Kasei Co., Ltd.
Amino group-containing epoxy compounds such as H-1402, ST-110, and YL-931 and YL-933 manufactured by Yuka Shell Epoxy Co., Ltd .; manufactured by Dainippon Ink and Chemicals, Inc.
Epicron TSR-601, EP made by Asahi Denka Kogyo Co., Ltd.
Rubber-modified epoxy compounds such as X-84-2 and EPX-4061; dicyclopentadiene phenolic epoxy compounds such as DCE-400 manufactured by Sanyo Kokusaku Pulp Co., Ltd .; silicone-modified epoxy compounds such as X-1359 manufactured by Asahi Denka Kogyo KK Epoxy compounds; ε-caprolactone-modified epoxy compounds such as PLACSEL G-402 and G-710 manufactured by Daicel Chemical Industries, Ltd .; Further, these epoxy compounds may also be partially esterified with (meth) acrylic acid or the like.

The preferred amount of the epoxy compound (F) used is
The amount is 5 to 75 parts by weight based on 100 parts by weight of the active energy ray-curable resin (A). If the proportion of the epoxy compound (F) exceeds the above range, in the case of the alkali developing type, the solubility of the unexposed portion in the developing solution is reduced, and the development residue tends to occur. In the case of the solvent developing type, The film is easily attacked by the developer, and the coating film easily falls off and blisters are generated, which makes practical use difficult. On the other hand, when the amount is less than the above range, the carboxyl group of the active energy ray-curable resin (A) remains in an unreacted state, so that the cured coating film has electrical properties (insulation resistance, electrolytic corrosion resistance), alkali resistance, solder heat resistance. sex,
It becomes difficult to sufficiently obtain electroless gold plating resistance. The carboxyl group of the active energy ray-curable resin (A) and the epoxy group of the epoxy compound (F) react by ring-opening polymerization, but the epoxy resin is easily soluble in the diluent (C) and other substances in the composition. When is used, the crosslinking is likely to proceed due to the heat at the time of drying. Therefore, when it is desired to suppress this and increase the drying time, it is desirable to use a hardly soluble epoxy resin alone or with an easily soluble epoxy resin. However, since a hardly soluble epoxy resin has low reactivity, it is preferable to use a curing accelerator together.

The photosensitive thermosetting resin composition of the present invention includes:
Barium sulfate, barium titanate, silicon oxide, amorphous silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, mica, etc., as required, to improve properties such as adhesion and hardness Known inorganic powders can be used, and the compounding ratio is 0 to 60% by weight of the photosensitive thermosetting resin composition, and preferably 5 to 40% by weight.

If necessary, known coloring agents such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black and naphthalene black, hydroquinone, hydroquinone monomethyl ether, tert-butyl Catechol, pyrogallol, known thermal polymerization inhibitors such as phenothiazine, orben, benton, known thickeners such as montmorillonite,
Known additives such as mineral oils such as silicones, fluorines and liquid paraffin, and defoamers such as acrylic copolymers, and / or leveling agents and antioxidants can be used.

Further, by adding a diallyl phthalate prepolymer or a diallyl isophthalate prepolymer as an organic filler, chemical resistance can be improved.
The amount of addition of the active energy ray-curable resin (A) 10
Up to 30 parts by weight, preferably up to 20 parts by weight, per 0 parts by weight can be used. If the amount exceeds 30 parts by weight, there is a problem that developability is remarkably deteriorated. As the above prepolymer, Daiso Dap, Daiso
There are isodap etc., average molecular weight 2,000-30,
000 are used. In particular, the average molecular weight is 5,000
0 to 20,000 diallyl isophthalate prepolymer is preferred.

For the purpose of enhancing the impact resistance of the cured coating film, copolymers of ethylenically unsaturated compounds such as acrylates or polyhydric alcohols and saturated or unsaturated polybasic acid compounds are used. Known binder resins such as synthesized polyester resins, and polyester (meth) synthesized from polyhydric alcohols, saturated or unsaturated polybasic acid compounds, and glycidyl (meth) acrylate
Known photosensitive oligomers such as acrylates and urethane (meth) acrylates synthesized from polyhydric alcohols, diisocyanates, and hydroxyl-containing (meth) acrylates do not affect various properties as a solder mask. Can be used in a range. However, among the above components, for binder materials such as copolymers of ethylenically unsaturated compounds such as acrylates and polyester resins, the amount of copolymers containing no photosensitive group and known binder resins is used. If the amount is too high, problems such as poor developability and sensitivity may occur. Therefore, the amount used is 10% by weight or less based on the active energy ray-curable resins (A) and (B), and 5% by weight or less based on the total composition. Is desirable.

The developer for forming the solder resist pattern after the photosensitive thermosetting resin composition of the present invention is selectively exposed through a photomask varies depending on the selection of the active energy ray-curable resin. , Cyclohexanone, xylene, tetramethylbenzene, butyl cellosolve, butyl carbitol, propylene glycol monomethyl ether, cellosolve acetate, propanol, propylene glycol, trichloroethane, trichloroethylene, modified trichloroethane (Eterna IR manufactured by Asahi Kasei Kogyo Co., Ltd. ) Made
Scowan EX-R, Kanden Triethane SR-A manufactured by Kanto Denka Kogyo Co., Ltd., Resisolve V- manufactured by Asahi Glass Co., Ltd.
5)), an aqueous alkali solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, and a surfactant aqueous solution.

The general method of using the photocurable thermosetting resin composition of the present invention is as follows:
After heating at 0 to 80 ° C. for 15 to 60 minutes to volatilize the organic solvent, a photomask of a desired pattern with a transparent image portion is placed on the coating film of the substrate, and irradiated with active energy rays, preferably ultraviolet rays. Is selectively exposed. This causes the composition in the exposed portions of the coating to crosslink and become insoluble. Next, the coating film is developed by removing unexposed portions with a dilute alkaline aqueous solution. As the dilute alkaline aqueous solution used here, a 0.5 to 5% by weight aqueous sodium carbonate solution is generally used. Of course, other alkaline aqueous solutions can be used. The pattern obtained in this manner is treated with ultraviolet light or 100 to 200 ° C. in order to improve heat resistance later.
It is desirable to perform secondary curing by heat or far infrared rays.

[0036]

EXAMPLES The present invention will be specifically described below with reference to Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited thereto. Note that “parts” and “%” are all based on weight unless otherwise specified.

Synthesis Example 1 (Synthesis of photosensitive prepolymer) 190 parts of a phenol novolak type epoxy compound (Epiclon N-770, manufactured by Dainippon Ink and Chemicals, Inc., epoxy equivalent = 190) was added to a thermometer, a dropping funnel and a stirrer. The mixture was placed in a four-necked flask equipped with a reflux condenser, and 141 parts of carbitol acetate was added, followed by heating and dissolving. Next, 0.1 part of hydroquinone as a polymerization inhibitor and 2.0 parts of triphenylphosphine as a reaction catalyst were added. The mixture was heated to 85 to 95 ° C., 72 parts of acrylic acid was gradually added dropwise, and the mixture was reacted with stirring for 16 hours.
An active energy ray-curable resin (R), which is a total esterified product of a 5% novolak epoxy compound with acrylic acid
-1) was obtained.

Examples 1 and 2 and Comparative Examples 1 and 2 The main components and the curing agent components of Examples 1 and 2 and Comparative Examples 1 and 2 shown in Table 1 were blended.
The mixture was kneaded twice to prepare a photosensitive thermosetting resin composition. Next, when the particle size was measured with a grind meter manufactured by Erichsen, it was 15 μm or less. The main component and the curing agent were mixed, and the obtained photosensitive thermosetting resin composition was applied to the entire surface of the copper through-hole printed wiring board by a screen printing method. Put in a hot air circulating oven, dry at 80 ° C for 20 minutes,
After cooling, the amount of irradiation of ultraviolet light having a wavelength of 365 nm was passed through a photomask and measured using an integrating light meter manufactured by Oak Manufacturing Co., Ltd.
Exposure was performed by adjusting the irradiation to 50 mJ / cm ² . After developing with a developing solution of 1% by weight of sodium carbonate at a spray pressure of ² kg / cm ² for 60 seconds, the temperature of the hot-air circulation type curing furnace was raised to 1%.
The temperature was set to 50 ° C., and the composition was thermally cured for 60 minutes to form a solder resist pattern.

[Table 1]

Table 2 shows the results of tests on various characteristics of the solder resist resin composition and solder resist pattern obtained in Examples 1 and 2 and Comparative Examples 1 and 2.
Shown in

[Table 2]

The characteristics shown in Table 2 above were tested and evaluated as follows. (1) Touch dryness A copper through-etched circuit board is applied by screen printing, dried at 80 ° C. for 10 minutes or 20 minutes in a hot-air circulation type drying furnace, and allowed to cool to room temperature (25 ° C.). The coated surface was strongly pressed with to examine the adhesiveness, and the state of the coating film was determined according to the following evaluation criteria. A: No stickiness or fingerprint mark was observed at all. : Slight stickiness and fingerprint marks on the surface. Δ: Remarkable stickiness and fingerprint marks are observed on the surface. X: The surface is completely tacky.

(2) Hot tack-free property The composition is coated on a copper through-etched circuit board by screen printing, dried in a hot-air circulation drying oven at 80 ° C. for 15 minutes, and allowed to cool. After being dried horizontally for 20 minutes, the state of the coating film was visually judged. ：: No scratches or dents were observed. ：: The surface is slightly scratched or dented. Δ: Notable scratches and dents are observed on the surface. ×: The surface is completely damaged.

(3) Developability test A copper through-etched circuit board was applied by screen printing, dried in a hot-air circulation drying oven at 80 ° C. for 20 minutes, allowed to cool, and then sprayed with a developer at a spray pressure of ² kg / cm ² . After the development for 60 seconds, the removed state was visually determined. A: Completely developed. ：: There is a part which is not developed easily on the surface. Δ: Development residual as a whole. X: Hardly developed.

(4) Photosensitivity test A copper through-etched circuit board was applied by screen printing, dried in a hot-air circulation drying oven at 80 ° C. for 20 minutes, allowed to cool, and irradiated with an ultraviolet light having a wavelength of 365 nm by an Oak Manufacturing Co., Ltd. 150 mJ / cm ² , 2
Irradiation was carried out by adjusting to 50 mJ / cm ² or 350 mJ / cm ^2, and developed with a developing solution at a spray pressure of ² kg / cm ² for 60 seconds, and the state of the coating film was visually judged. No change is observed. ：: The surface is slightly changed. Δ: The surface is significantly changed. ×: The coating film comes off.

(5) Adhesion test A copper-through-etched circuit board was applied by screen printing, dried at 80 ° C. for 20 minutes in a hot air circulating drying oven, allowed to cool, passed through a photomask, and irradiated with ultraviolet light having a wavelength of 365 nm. Is irradiated at 350 mJ / cm ² using an integrating light meter manufactured by Oak Manufacturing Co., Ltd.
g / cm ² for 60 seconds, and
What was post-cured at 50 ° C for 60 minutes was subjected to JISD02
According to the test method of No. 02, a grid-like cross cut was made, and then the state of peeling after the peeling test with a cellophane adhesive tape was visually judged. A: 100/100 without any peeling. ：: The cross cut portion was slightly peeled off at 100/100. Δ: Peeled in the range of 50/100 to 90/100. ×: Peeled in the range of 0/100 to 50/100.

(6) Pencil hardness test Each test piece produced in the same manner as in the adhesion test (5) was measured for hardness under a load of 1 kg in accordance with the test method of JIS K5400.

(7) Acid Resistance Test Each test piece prepared in the same manner as in the adhesion test (5) was immersed in a 10% by volume aqueous sulfuric acid solution at 20 ° C. for 30 minutes and taken out. Judgment comprehensively,
evaluated. A: No change was observed. ：: slightly changed. Δ: Notably changed. X: The coating film has blisters or swelling and falling off.

(8) Alkali Resistance Test An acid resistance test was carried out in the same manner as in the acid resistance test (7) except that the 10% by volume aqueous sulfuric acid solution was replaced with a 10% by weight aqueous sodium hydroxide solution.
evaluated.

(9) Solvent resistance test An acid resistance test (7) was conducted and evaluated in the same manner as in the acid resistance test (7), except that the 10% by volume aqueous sulfuric acid solution was replaced with acetone.

(10) Electroless Gold Plating Resistance Test Each of the test pieces prepared in the same manner as in the adhesion test (5) was subjected to a test using “Ourlectroless UP” (a plating solution manufactured by Meltex Co., Ltd.) for 85%. The state of the coating film after plating at a solution temperature of 30 ° C. for 30 minutes to deposit gold having a thickness of 0.05 μm was evaluated in the same manner as in the acid resistance test (7).

(11) Solder heat resistance test The same test pieces as those in the adhesion test (5) were used, respectively.
According to the test method of SC6481, the state of the coating film after immersion once and three times in a 260 ° C. solder bath for 10 seconds was evaluated in the same manner as in the acid resistance test (7).

(12) Insulation Resistance Measurement Using the comb test pattern B of IPC-B-25, test pieces were prepared under the same conditions as in the adhesion test (5), and the initial and relative temperatures were 85 ° C. and relative humidity. The insulation resistance was measured after applying humidification for 500 hours under the conditions of 85% DC 50V application.

(13) Electrocorrosion resistance test Using a comb type test pattern B of IPC-B-25, test pieces were prepared under the same conditions as in the adhesion test (5), and the relative temperature was 85 ° C. and the relative humidity was 85%. , DC 50V
The discoloration of the copper foil after the application of humidification for 500 hours under the application conditions was examined. A: No change was observed. ：: slightly changed. Δ: Notably changed. X: The coating film has blisters or swelling and falling off.

(14) Measurement of Resolution A copper through-etched circuit board was applied by screen printing, dried at 80 ° C. in a hot-air circulation drying oven, allowed to cool, and then subjected to a photomask (each having a line of 30 μm to 100 μm). Using an integrated light meter manufactured by Oak Manufacturing Co., Ltd. at 350 m
After irradiating with a J / cm ² adjustment, and developing with a developing solution at a spray pressure of ² kg / cm ² for 60 seconds, the state of the remaining lines in the exposed area and the state of space escape were visually determined. did.

(15) Sensitivity measurement The copper through etching circuit board is applied by screen printing,
The test pieces were dried at 80 ° C. in a hot-air circulation drying oven and allowed to cool, and passed through a photomask (Step Tablet No. 2 manufactured by Eastman Kodak Co., Ltd.). Irradiation was carried out using an integrating light meter manufactured by Oak Manufacturing Co., Ltd. so as to be adjusted to 350 mJ / cm ^2.
After developing for 60 seconds at a spray pressure of m ² , the number of steps of the remaining coating film was visually determined.

[0055]

As described above, the photosensitive thermosetting resin composition of the present invention can be developed with a dilute alkali aqueous solution, and has the photocurability, developability, solder heat resistance, Solvent resistance, chemical resistance, adhesion, electrical insulation,
It has excellent properties such as corrosion resistance, especially the dryness to the touch, hot tack-free properties, resolution, and electroless gold plating resistance have been dramatically improved. It can also cope with the SMT accompanying the development.

Continued on the front page F-term (reference) 2H025 AA00 AA04 AA06 AA07 AA08 AA10 AA20 AB15 AB20 AC01 AD01 BC12 BC14 BC31 BC34 BC43 BC53 BC62 BC73 BC82 BC83 BC85 BC86 CA00 CC03 CC08 CC17 DA18 EA04 EA10 FA17 FA29 5E314 AA33 BB01 GG03 GG10 GG11 GG14

Claims (6)

[Claims] 1. An active energy ray-curable resin obtained by reacting (A) (a) a carboxyl group-containing (meth) acrylic copolymer resin with (b) an alicyclic epoxy group-containing unsaturated compound, An) active energy ray-curable resin having two or more unsaturated groups in one molecule and having a cyclic skeleton;
A photosensitive thermosetting resin composition comprising (C) a diluent, (D) a photopolymerization initiator, (E) a latent curing adhesion promoter, and (F) an epoxy compound as essential components. 2. The photosensitive thermosetting resin composition according to claim 1, wherein the active energy ray-curable resin (A) has an acid value in the range of 50 to 150 mgKOH / g. 3. The active energy ray-curable resin (B) comprises:
(C) a photosensitive prepolymer (B-1), which is a total esterified product of an epoxy group generated by an esterification reaction between a novolak type epoxy compound and (d) an unsaturated carboxylic acid;
And a reaction product of (e) a diisocyanate and (f) a (meth) acrylate having one hydroxyl group in one molecule is reacted with a secondary hydroxyl group of the photosensitive prepolymer (B-1). At least one selected from the group consisting of the photosensitive prepolymers (B-2) to be prepared, wherein the mixing ratio of the components (A) and (B) is 100: 2 to 100: 50.
3. The photosensitive thermosetting resin composition according to claim 1, wherein the composition is (weight basis). 4. The photosensitive thermosetting resin composition according to claim 1, further comprising an inorganic filler. 5. The photosensitive thermosetting resin composition according to claim 1, which is used as a solder resist. 6. The photosensitive thermosetting resin composition according to claim 1, applied to a printed wiring board, preliminarily dried, and then selectively exposed to active energy rays through a photomask. A method for forming a solder resist pattern, comprising exposing and photopolymerizing, developing an unexposed portion with a developer to form a resist pattern, and then heating and thermosetting.