KR101660583B1 - Photosensitive resin composition, dry film, cured product, and printed wiring board - Google Patents

Abstract

The present invention provides an alkaline developing photosensitive resin composition which is less likely to generate outgas and which has excellent touch-to-dryness and developability, a dry film containing the composition, a cured product thereof, and a printed wiring board having the cured product.
The composition is an alkali developing type photosensitive resin composition containing (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) an epoxy resin and (D) a (meth) acrylic monomer, and (B) an acylphosphine Based photopolymerization initiator, and (C) a bisphenol A novolak type epoxy resin as an epoxy resin.

Description

TECHNICAL FIELD [0001] The present invention relates to a photosensitive resin composition, a dry film, a cured product, and a printed wiring board,

The present invention relates to a photosensitive resin composition, a dry film, a cured product and a printed wiring board.

Description of the Related Art [0002] In a printed wiring board generally used in electronic equipment or the like, in order to prevent solder from adhering to an unnecessary portion, and to prevent a conductor of a circuit from being exposed and being corroded by oxidation or moisture, A solder resist is formed in the region except for the hole.

As a method of forming a solder resist of a desired pattern on a substrate, a forming method using a photolithography technique is used. For example, a photosensitive solder resist containing an alkali development type photosensitive resin composition is exposed through a pattern mask and then subjected to alkali development to form a pattern using a difference in solubility in an alkali developing solution generated in an exposed portion and an unexposed portion can do.

There is a problem of so-called outgas that the components contained in the photopolymerization initiator or the like are volatilized and gasified to contaminate the surroundings during the photopolymerization or after the thermal curing which is carried out if necessary, there was. For example, Patent Document 1 discloses a photosensitive resin composition containing an onium borate complex as a photosensitive composition with little outgassing.

In addition, as the exposure method, a contact exposure which forms a solder resist layer on a substrate having a circuit formed thereon, followed by drying, and then exposing the phototool in a vacuum contact state is the mainstream. At this time, if the dry touching property of the dry coating film is poor, there is a problem that the phototool sticks to the coated film and the phototool can not be peeled off, or the dry film peels off from the substrate. In addition, with the recent trend of shortening the length and width of electronic devices, the photosensitive resin composition is required to have high developing property in order to form a fine pattern.

Japanese Patent Application Laid-Open No. 2005-336314

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an alkali developing photosensitive resin composition which is less prone to outgassing and which is superior in touch-to-dry development and developability, a dry film containing the composition, a cured product thereof, and a printed wiring board having the cured product .

DISCLOSURE OF THE INVENTION The present inventors have intensively studied in view of the above, and as a result, discovered that the above problems can be solved by combining an acylphosphine oxide-based photopolymerization initiator and a bisphenol A novolac-type epoxy resin.

That is, the alkali-developable photosensitive resin composition of the present invention is an alkali-developable photosensitive resin composition containing (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) an epoxy resin, and (D) (B) an acylphosphine oxide-based photopolymerization initiator as a photopolymerization initiator, and (C) a bisphenol A novolak-type epoxy resin as an epoxy resin.

The alkali-developable photosensitive resin composition of the present invention preferably further contains (E) an inorganic filler.

The alkali-developable photosensitive resin composition of the present invention preferably contains spherical silica as the inorganic filler (E).

The dry film of the present invention is characterized by being obtained by applying and drying the above alkali-developable photosensitive resin composition to a film.

The cured product of the present invention is characterized in that the dry film obtained by applying and drying the above alkali-developable photosensitive resin composition or alkali-developable photosensitive resin composition to a film is obtained by performing at least one of photo-curing and thermosetting .

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

According to the present invention, it is possible to provide an alkaline developing photosensitive resin composition which is less likely to generate outgas and which is excellent in terms of touching dryness and developability, a dry film containing the composition, a cured product thereof and a printed wiring board having the cured product have.

Each component of the alkali-developable photosensitive resin composition of the present invention will be described below. In addition, unless otherwise specified, the numerical range expressed by using the symbol " ~ () " in the present specification is intended to include a range including a numerical value of its upper limit and lower limit (i.e., ).

[(A) Resin containing a carboxyl group]

The alkali-developable photosensitive resin composition of the present invention contains (A) a carboxyl group-containing resin. As the carboxyl group-containing resin (A), a resin containing a known carboxyl group can be used. By the presence of a carboxyl group, the resin composition can be rendered alkali-developable. It is preferable that the alkali-developable photosensitive resin composition of the present invention has an ethylenically unsaturated bond in a molecule other than a carboxyl group in view of photocuring property or resistance to development, but only a carboxyl group-containing water having no ethylenically unsaturated double bond is used It is possible. The ethylenically unsaturated double bond is preferably derived from acrylic acid or methacrylic acid or a derivative thereof.

Specific examples of the carboxyl group-containing resin that can be used in the alkali-developable photosensitive resin composition of the present invention include the following compounds (which may be oligomers and polymers).

(1) A carboxyl group-containing resin obtained by copolymerization of an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound such as styrene,? -Methylstyrene, lower alkyl (meth) acrylate or isobutylene.

(2) Diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates and aromatic diisocyanates, carboxyl-containing dialcohol compounds such as dimethylolpropionic acid and dimethylolbutanoic acid, and polycarbonate-based polyols, polyether Containing carboxyl groups in a diol compound such as polyol, polyol, polyester polyol, polyolefin polyol, acrylic polyol, bisphenol A alkylene oxide adduct diol, phenolic hydroxyl group and alcoholic hydroxyl group. Urethane resin.

(3) A process for producing a polyisocyanate compound, which comprises reacting a diisocyanate compound such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate or an aromatic diisocyanate with a polycarbonate-based polyol, a polyether- , A terminal carboxyl group-containing urethane resin obtained by reacting an acid anhydride at the terminal of a urethane resin by a heavy-chain reaction of a diol compound such as a bisphenol A-based alkylene oxide adduct diol, a phenolic hydroxyl group and a compound having an alcoholic hydroxyl group .

(4) a bifunctional epoxy resin such as a bisphenol A type epoxy resin, a hydrogenated bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a beacilene type epoxy resin and a biphenol type epoxy resin (Meth) acrylate or a partial acid anhydride thereof, a carboxyl group-containing dialcohol compound and a diol compound.

(5) A compound having one hydroxyl group and at least one (meth) acryloyl group in the molecule such as hydroxyalkyl (meth) acrylate is added during the synthesis of the resin of the above (2) or (4) ) Urethane resin containing an acrylated carboxyl group.

(6) A compound having one isocyanate group and at least one (meth) acryloyl group in the molecule, such as a conformal reaction product of isophorone diisocyanate and pentaerythritol triacrylate during the synthesis of the resin of the above (2) or (4) (Meth) acrylate having a carboxyl group.

(7) A photosensitive resin containing a photosensitive carboxyl group-containing resin obtained by reacting a polyfunctional (solid) epoxy resin with (meth) acrylic acid and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride or hexahydrophthalic anhydride to the hydroxyl groups present in the side chain .

(8) A photosensitive carboxyl group-containing resin obtained by reacting a polyfunctional epoxy resin obtained by further epoxidizing a hydroxyl group of a bifunctional (epoxy) epoxy resin with epichlorohydrin, and reacting (meth) acrylic acid with the resulting hydroxyl group added with a dibasic acid anhydride.

(9) A carboxyl group-containing polyester resin in which a dicarboxylic acid is reacted with a polyfunctional oxetane resin, and a dibasic acid anhydride is added to the resulting primary hydroxyl group.

(10) A process for producing a polyoxyalkylene compound, which comprises reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in a molecule with an alkylene oxide such as ethylene oxide or propylene oxide with a monocarboxylic acid containing an unsaturated group, A carboxyl group-containing photosensitive resin obtained by reacting an anhydride.

(11) reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in a molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate to react the unsaturated group-containing monocarboxylic acid with the resulting product A photosensitive resin containing a carboxyl group obtained by reacting a reaction product with a polybasic acid anhydride.

(12) A process for producing an epoxy compound having a plurality of epoxy groups in a molecule, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule such as p-hydroxyphenethyl alcohol, and a compound having an unsaturated (meth) Containing carboxylic acid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, or adipic anhydride is reacted with an alcoholic hydroxyl group of the obtained reaction product, Containing photosensitive resin.

(13) The resin composition according to any one of (1) to (12) above, wherein one epoxy group in the molecule such as glycidyl (meth) acrylate and? -Methyl glycidyl (meth) ) A photosensitive carboxyl group-containing resin obtained by further adding a compound having an acryloyl group.

Since the carboxyl group-containing resin has a large number of carboxyl groups in the side chain of the backbone polymer, development with a dilute aqueous alkali solution becomes possible.

The acid value of the carboxyl group-containing resin is preferably in the range of 20 to 200 mg KOH / g, and more preferably in the range of 40 to 150 mg KOH / g. When the concentration is in the range of 20 to 200 mgKOH / g, the adhesion of the coating film is obtained, the alkali development is facilitated, the dissolution of the exposed portion by the developer is suppressed, the line is not unnecessarily narrowed, Dissolution and peeling of the resist pattern are suppressed and the normal resist pattern is easily drawn.

The weight average molecular weight of the carboxyl group-containing resin used in the present invention varies depending on the resin skeleton, but is preferably in the range of 2,000 to 150,000. Within this range, the non-sticking performance is good, the moisture resistance of the coated film after exposure is good, the film is hardly reduced during development, the resolution is improved, the developing property is good, and the storage stability is good. More preferably from 5,000 to 100,000. The weight average molecular weight can be measured by gel permeation chromatography.

Among the above carboxyl group-containing resins, the carboxyl group-containing resins of the above (7) and (8) are preferable from the balance of respective characteristics such as touch dryness, developability, outgas and undercut.

In the present specification, (meth) acrylate is generically referred to as acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

[(B) Photopolymerization initiator]

The alkali-developable photosensitive resin composition of the present invention contains (B) an acylphosphine oxide-based photopolymerization initiator as a photopolymerization initiator. The acylphosphine oxide-based photopolymerization initiator may be any photopolymerization initiator or an acylphosphine oxide-based photopolymerization initiator known as a photoradical generator. Specific examples include (2,6-dimethoxybenzoyl) -2,4,4-pentylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2-methylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylphosphinic acid Methyl ester, bis (2,6-dimethoxybenzoyl) phenylphosphine oxide, ethyl-2,4,6-trimethylbenzoyl phenylphosphinate, and the like. Commercially available products include lucylline TPO, lucylline TPO-L, LR8953X, Irgacure 819 and Irgacure 1700 manufactured by BASF Japan.

As the acylphosphine oxide-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator having a group represented by the following general formula (I) is preferable.

(Wherein R ¹ and R ² are each independently a halogen atom, a straight or branched alkyl group having 1 to 6 carbon atoms, a straight or branched alkoxy group having 1 to 6 carbon atoms, An aryl group having 6 to 20 carbon atoms which may be substituted with at least one of a cycloalkyl group having 5 to 20 carbon atoms, an alkyl group and an alkoxy group, or an aryl group having 6 to 20 carbon atoms which may be substituted with at least one of an alkyl group and an alkoxy group, An arylcarbonyl group having 7 to 20 carbon atoms)

Examples of the halogen atom include fluorine, chlorine, bromine, and iodine. Examples of the linear or branched alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl and hexyl. Examples of the straight chain or branched alkoxy group having 1 to 6 carbon atoms include a methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group and hexyloxy group. Examples of the cycloalkyl group having 5 to 20 carbon atoms include a cyclopentyl group, a cyclohexyl group, and those wherein the cycloalkyl group is substituted with an alkyl group, an alkoxy group, or the like. Examples of the aryl group having 6 to 20 carbon atoms which may be substituted with at least one of the alkyl group and the alkoxy group include a phenyl group and a naphthyl group which may be substituted with at least one of an alkyl group and an alkoxy group, . The arylcarbonyl group having 7 to 20 carbon atoms which may be substituted with at least any one of the alkyl group and the alkoxy group is A- (C = O) - (wherein A is substituted with at least any one of the alkyl group and the alkoxy group, Or an aryl group which may be present). Specific examples thereof include a benzoyl group and a trimethylbenzoyl group.

Among the above-mentioned acylphosphine oxide-based photopolymerization initiators, a bisacylphosphine oxide-based photopolymerization initiator is preferable because it improves the adhesion to the atmosphere and suppresses outgassing. As the bisacylphosphine oxide photopolymerization initiator, bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphine oxide, Bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- , 4,6-trimethylbenzoyl) phenylphosphine oxide, (2,5,6-trimethylbenzoyl) -2,4,4-trimethylpentylphosphine oxide, and the like. Among them, bis- (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure 819 manufactured by BASF Japan Co., Ltd., as a commercially available product) is preferable because it has excellent deep-part curability and, as a result, undercut is less likely to occur.

The acylphosphine oxide-based photopolymerization initiator may be used alone, or two or more acylphosphine oxide photopolymerization initiators may be used in combination. The blending amount of the acylphosphine oxide-based photopolymerization initiator is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the carboxyl-containing resin (A) in terms of solid content. In this range, the photocurability on copper is sufficient, the curability of the coating film is improved, the coating film properties such as chemical resistance are improved, and the deep curing property is also improved. More preferably 0.5 to 15 parts by mass based on 100 parts by mass of the carboxyl-containing resin (A).

[(C) Epoxy resin]

The alkali-developable photosensitive resin composition of the present invention contains bisphenol A novolak type epoxy resin (C) as an epoxy resin. In the present invention, by using the bisphenol A novolak type epoxy resin and the acylphosphine oxide-based photopolymerization initiator in combination, it is possible to suppress the generation of outgas synergistically and to improve the on- Can be obtained. The bisphenol A novolak type epoxy resin is not particularly limited as long as it is a conventionally known one. Commercially available products of the bisphenol A novolak type epoxy resin include jER157S manufactured by Mitsubishi Chemical Corporation.

The blending amount of the bisphenol A novolak type epoxy resin is preferably 1 to 100 parts by mass relative to 100 parts by mass of the carboxyl group-containing resin (A) in terms of solid content. In this range, the developability is improved, the curability is improved, and various general characteristics such as solder heat resistance are improved. Further, sufficient toughness is obtained, and storage stability is not lowered. More preferably 2 to 70 parts by mass. The alkali-developable photosensitive resin composition of the present invention may contain other epoxy resin within the range not impairing the effect of the present invention.

[(D) (Meth) acrylic monomer]

The alkali-developable photosensitive resin composition of the present invention contains (D) a (meth) acrylic monomer. (Meth) acryl monomer is a compound having a (meth) acryloyl group in the molecule. The (meth) acryl monomer is to assist the photo-curing of the carboxyl group-containing resin by irradiation with active energy rays.

As the (D) (meth) acrylic monomer, a known (meth) acrylic monomer may be used. Examples thereof include polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate and epoxy (meth) acrylate. Specific examples thereof include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; Diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol and propylene glycol; Acrylamides such as N, N-dimethyl acrylamide, N-methylol acrylamide and N, N-dimethylaminopropylacrylamide; Aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate and N, N-dimethylaminopropyl acrylate; Polyhydric alcohols such as hexanediol, trimethylol propane, pentaerythritol, dipentaerythritol and tris-hydroxyethylisocyanurate, or ethylene oxide adducts thereof, propylene oxide adducts, or? -Caprolactone adducts Polyhydric acrylates; Polyfunctional acrylates such as phenoxy acrylate, bisphenol A diacrylate and ethylene oxide adducts or propylene oxide adducts of these phenols; Polyhydric acrylates of glycidyl ethers such as glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylol propane triglycidyl ether and triglycidyl isocyanurate; But are not limited to, the polyols such as polyether polyol, polycarbonate diol, hydroxyl-terminated polybutadiene, and polyester polyol, which are directly acrylated or urethane-acrylated through diisocyanate, and melamine acrylate And the respective methacrylates corresponding to the acrylate.

In addition, epoxy acrylate resins obtained by reacting polyfunctional epoxy resins such as cresol novolak type epoxy resins with acrylic acid, and epoxy acrylate resins obtained by reacting hydroxyacrylates such as pentaerythritol triacrylate and isophorone di An epoxy urethane acrylate compound obtained by reacting a half urethane compound of a diisocyanate such as isocyanate may be used as the (meth) acrylic monomer. Such an epoxy acrylate resin can improve photo-curability without deteriorating the touch-dry composition.

The blending amount of the (D) (meth) acrylic monomer is preferably 5 to 100 parts by mass based on 100 parts by mass of the carboxyl group-containing resin (A) in terms of solid content. In this range, the photocurability is improved, the pattern formation is facilitated by the alkali development after the irradiation with the active energy ray, and the strength of the coating film is improved. More preferably 5 to 70 parts by mass.

((E) inorganic filler)

The alkali-developable photosensitive resin composition of the present invention preferably contains (E) an inorganic filler. Examples of the inorganic filler (E) include calcium carbonate, magnesium carbonate, fly ash, dehydrated sludge, natural silica, synthetic silica, kaolin, clay, calcium oxide, magnesium oxide, titanium oxide, zinc oxide, barium sulfate, , Magnesium hydroxide, talc, mica, hydrotalcite, aluminum silicate, magnesium silicate, calcium silicate, calcined talc, wollastonite, potassium titanate, magnesium sulfate, calcium sulfate, magnesium phosphate, hemihalite, zonolite, boron nitride, A glass powder, a neuburger diatomaceous earth, a diatomaceous earth, a soda lime glass, a silica glass, a steel ball, a balloon, a glass flake, a glass balloon, silica, steel slag, copper, iron, iron oxide, carbon black, Antimony trioxide, magnesium oxysulfate, aluminum hydrate, hydrated gypsum, and alum. These inorganic fillers may be used singly or in combination of two or more kinds.

As the inorganic filler (E), spherical silica is particularly preferable in that the undercut is particularly reduced. The spherical silica is preferably any spherical silica usable as a filler for electronic materials. The average particle diameter (D50) of the spherical silica may be 0.01 to 5 mu m, preferably 0.1 to 3 mu m. The average particle diameter is measured by laser diffraction. The spherical silica may be a surface treated with a silane coupling agent.

The shape of the spherical silica may be spherical, and is not limited to spherical silica. Suitable spherical silicas include, for example, those having a sphericity of not less than 0.8 as measured in the following manner, but are not limited thereto.

The sphericity is measured as follows. A photograph is taken with an SEM and is calculated as a value calculated from the area and the circumference of the observed particle (sphericity) = {4 pi x (area) / (circumferential length) ² }. Specifically, an average value measured for 100 particles is adopted by using an image processing apparatus.

The method for producing spherical silica is not particularly limited, and a method known to those skilled in the art can be applied. For example, it can be produced by burning silicon powder by VMC (Vaporized Metal Combustion) method. The VMC method is a method in which a chemical salt is formed by a burner in an atmosphere containing oxygen and a metal powder constituting a part of a target oxide particle is charged into the chemical salt to such an extent that dust cloud is formed, To obtain oxide particles.

Examples of the commercially available spherical silica include SO series (Admafine SO-E2, Admapine SO-E5, etc.) manufactured by Admatech, HPS series (HPS-0500, HPS-1000 and HPS3500 manufactured by Doago Kosei Co., Ltd.) .

The spherical silica may be used singly or in combination of two or more kinds. The blending amount of the spherical silica is preferably 30 to 70 parts by mass, more preferably 40 to 60 parts by mass, based on 100 parts by mass of the carboxyl-containing resin (A) in terms of solid content. When the amount is in the range of 30 to 70 parts by mass, when the substrate is laminated on the substrate as a dry film, embedding in a substrate or a circuit and good cooling / heating cycle characteristics are obtained.

(Other photopolymerization initiator)

The alkali-developable photosensitive resin composition of the present invention may contain a known photopolymerization initiator other than the acylphosphine oxide-based photopolymerization initiator. Examples thereof include benzoin such as benzoin, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isopropyl ether and benzoin n-butyl ether; Benzoin alkyl ethers; Benzophenones such as benzophenone, p-methylbenzophenone, Michler's ketone, methylbenzophenone, 4,4'-dichlorobenzophenone, and 4,4'-bisdiethylaminobenzophenone; Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, N, N-dimethylaniline, N, N-diethylamino-1- (4- Acetophenones such as N-dimethylaminoacetophenone; Thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-di Thioxanthones such as isopropylthioxanthone; Anthraquinones such as anthraquinone, chloroanthraquinone, 2-methyl anthraquinone, 2-ethyl anthraquinone, 2-tert-butyl anthraquinone, 1-chloro anthraquinone, 2-amylanthraquinone and 2-aminoanthraquinone; Ketal such as acetophenone dimethyl ketal and benzyl dimethyl ketal; Benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2- (dimethylamino) ethylbenzoate and p-dimethylbenzoic acid ethyl ester; (9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-2-yl) Oxime esters such as 3-yl] -, 1- (O-acetyloxime); Bis (η ⁵ -2,4- cyclopentadiene-1-yl) -bis (2,6-difluoro -3- (1H- pyrrol-1-yl) phenyl) titanium, bis (cyclopentadienyl) Titanocenes such as bis [2,6-difluoro-3- (2- (1-phenyl-1-yl) ethyl) phenyl] titanium; Phenyl disulfide, 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, tetramethylthiuram disulfide, and the like. These photopolymerization initiators may be used singly or in combination of two or more.

In the case of using a photopolymerization initiator including an acylphosphine oxide system, since sensitivity to light at the time of exposure can be improved, thioacetic acid (hereinafter also referred to as " thioxanthone photopolymerization initiator ") is used . As the thioxanthene photopolymerization initiator, 2,4-diethylthioxanthone is more preferably used. The blending amount of the thioxanthene photopolymerization initiator is preferably 0.05 to 2 parts by mass, more preferably 0.1 to 1.6 parts by mass based on 100 parts by mass of the carboxyl group-containing resin (A) in terms of solid content. When the amount is in the range of 0.05 to 2 parts by mass, the effect of improving the sensitivity is large, and as a result, the undercut is easily suppressed and out gas is hardly generated.

(Thermosetting component)

The alkali-developable photosensitive resin composition of the present invention may contain a thermosetting component other than the bisphenol A novolac-type epoxy resin. The thermosetting component may be one which reacts with a carboxyl group-containing resin, and examples thereof include an epoxy compound other than the bisphenol A novolak type epoxy resin, a compound having an amino group, an oxetane compound, and an isocyanate compound.

Examples of the epoxy compound include epoxidized vegetable oil; Bisphenol A type epoxy resin; Hydroquinone type epoxy resins; Bisphenol-type epoxy resins; Thioether type epoxy resin; Brominated epoxy resin; Novolak type epoxy resins; Biphenol novolak type epoxy resins; Bisphenol F type epoxy resin; Hydrogenated bisphenol A type epoxy resin; Glycidylamine type epoxy resins; Hidanto dolphin epoxy resin; Alicyclic epoxy resins; Trihydroxyphenylmethane type epoxy resin; Biscylenol type or biphenol type epoxy resins or mixtures thereof; Bisphenol S type epoxy resin; Tetraphenylol ethane type epoxy resin; Heterocyclic epoxy resins; Diglycidyl phthalate resin; Tetraglycidylsilanoy ethane resin; A naphthalene group-containing epoxy resin; An epoxy resin having a dicyclopentadiene skeleton; Glycidyl methacrylate copolymer epoxy resin; A copolymerized epoxy resin of cyclohexylmaleimide and glycidyl methacrylate; Epoxy-modified polybutadiene rubber derivatives; CTBN-modified epoxy resin, and the like, but are not limited thereto. From the viewpoint of reactivity, an epoxy compound having two or more functional groups is preferable.

Examples of the compound having an amino group include amino resins such as melamine derivatives and benzoguanamine derivatives. For example, methylolmelamine compounds, methylolbenzoguanamine compounds, methylol glycoluril compounds, and methylol urea compounds. The alkoxymethylated melamine compound, the alkoxymethylated benzoguanamine compound, the alkoxymethylated glycoluril compound, and the alkoxymethylated urea compound may be prepared by reacting the respective methylolmelamine compound, methylolbenzoguanamine compound, methylolglycoluril compound, and methylol urea compound Is converted into an alkoxymethyl group. The kind of the alkoxymethyl group is not particularly limited, and examples thereof include a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, and a butoxymethyl group. Particularly, a melamine derivative having a formalin concentration of 0.2% or less which is friendly to human body and environment is preferable.

Examples of the oxetane compound include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [ Methyl-3-oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) (3-ethyl-3-oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, In addition to polyfunctional oxetanes such as oligomers and copolymers, oxetane alcohol and novolak resins, poly (p-hydroxystyrene), cardo type bisphenols, calixarene, calix resorcinarene or silsesquioxane And etherified with a resin having a hydroxyl group such as oxalic acid. In addition to these, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate may also be used.

As the isocyanate compound, a polyisocyanate compound having a plurality of isocyanate groups in the molecule can be used. As the polyisocyanate compound, for example, aromatic polyisocyanate, aliphatic polyisocyanate or alicyclic polyisocyanate is used. Specific examples of the aromatic polyisocyanate include 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylene diisocyanate, m -Xylene diisocyanate and 2,4-tolylene diisocyanate dimer. Specific examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylene bis (cyclohexyl isocyanate) and isophorone diisocyanate. Specific examples of the alicyclic polyisocyanate include bicycloheptane triisocyanate, and adducts, burettes and isocyanurates of the isocyanate compounds exemplified above. The isocyanate compound may be a block isocyanate compound in which the isocyanate group is protected by a blocking agent to temporarily inactivate it.

Other thermosetting components may be used, or known thermosetting components such as maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, and episulfide resins may be used.

(solvent)

The alkali-developable photosensitive resin composition of the present invention may contain a known organic solvent for adjusting the viscosity of the composition or adjusting viscosity for application to a substrate or a carrier film. Examples of the solvent include toluene, xylene, ethyl acetate, butyl acetate, methanol, ethanol, isopropyl alcohol, isobutyl alcohol, 1-butanol, diacetone alcohol, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, Ether acetate, terpineol, methyl ethyl ketone, carbitol, carbitol acetate, butyl carbitol, butyl carbitol acetate and the like. The solvent may be used alone, or two or more solvents may be used in combination.

(Other optional components)

The alkali-developable photosensitive resin composition of the present invention may contain known additives in the field of electronic materials. Examples of additives include thermosetting catalysts, thermal polymerization inhibitors, ultraviolet absorbers, silane coupling agents, plasticizers, flame retardants, antistatic agents, antioxidants, antibacterial and antifungal agents, antifoaming agents, leveling agents, fillers other than the above, thickeners, A tropic imparting agent, a coloring agent, a photoinitiator, and a sensitizer.

The alkali-developable photosensitive resin composition of the present invention may be in the form of a dry film comprising a carrier film (support) and a layer containing the alkali-developable photosensitive resin composition formed on the carrier film.

In the case of dry film formation, the alkali-developable photosensitive resin composition of the present invention is diluted with the above-mentioned organic solvent, adjusted to an appropriate viscosity, and then applied in a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, A gravure coater, a spray coater or the like to a uniform thickness on a carrier film and dried at a temperature of usually 50 to 130 ° C for 1 to 30 minutes to obtain a film. The thickness of the coating film is not particularly limited, but is generally appropriately selected in the range of 10 to 150 占 퐉, preferably 20 to 60 占 퐉 in the film thickness after drying.

As the carrier film, a plastic film is used, and it is preferable to use a plastic film such as a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, and a polystyrene film. The thickness of the carrier film is not particularly limited, but is generally appropriately selected in the range of 10 to 150 mu m.

It is preferable to further laminate a peelable cover film on the surface of the film for the purpose of preventing dust from adhering to the surface of the film after forming the alkali-developable photosensitive resin composition of the present invention on the carrier film.

As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used. When the cover film is peeled off, It is preferable that the adhesive force with the film is smaller.

The alkali-developable photosensitive resin composition of the present invention can be prepared, for example, by adjusting the viscosity with a suitable viscosity for the application method with the organic solvent described above, and applying the coating solution onto the substrate by a dip coating method, a flow coating method, a roll coating method, a bar coater method, Curtain coating method and the like, and then the organic solvent contained in the composition is volatilized and dried (dried) at a temperature of about 60 to 100 DEG C, whereby a non-stick coating film can be formed. Further, in the case of a dry film obtained by applying the above composition onto a carrier film and drying the same, the alkali developing type photosensitive resin composition layer is bonded to the base material by a laminator or the like so as to be in contact with the base material, A resin insulating layer can be formed.

As the above substrate, in addition to a printed wiring board or a flexible printed wiring board which has been previously formed on a circuit, it is possible to use a substrate such as paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / nonwoven epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, (FR-4 and the like), other polyimide films, PET films, glass substrates, glass substrates, and the like. A ceramic substrate, a wafer plate, and the like.

The volatile drying after application of the alkali-developable photosensitive resin composition of the present invention can be carried out by a hot-air circulating drying furnace, a hot plate, a convection oven or the like (a dryer equipped with a heat source of air- A method in which hot air in the nozzle is countercurrently contacted, and a method in which hot air in the nozzle is jetted onto the support).

The alkali-developable photosensitive resin composition of the present invention is heated at a temperature of, for example, about 140 to 180 占 폚 to thermally cure, whereby the carboxyl group of the carboxyl-containing resin (A) and the epoxy resin (C) It is possible to form a cured coating film excellent in various properties such as chemical resistance, hygroscopicity, adhesion, electrical characteristics and the like.

The exposed portions (portions irradiated with active energy rays) are cured by performing exposure (irradiation with active energy rays) on the coating film obtained by applying the alkali-developable photosensitive resin composition of the present invention and volatilizing and drying the solvent. Alternatively, the resist pattern may be directly pattern-exposed by an exposure light or a laser direct exposure machine through a photomask having a pattern formed by a contact (or noncontact) method, and the unexposed portion may be exposed to an alkali solution (for example, 3 wt% aqueous sodium carbonate solution) to form a resist pattern.

The exposure apparatus used for the active energy beam irradiation may be a device for mounting a high-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, etc. and irradiating ultraviolet rays in the range of 350 to 450 nm, (For example, a laser direct imaging apparatus that draws images with a laser directly by CAD data from a computer) can also be used. As the laser light source of the direct shot type, either a gas laser or a solid laser may be used if laser light having a maximum wavelength in the range of 350 to 410 nm is used. Light exposure for image formation film varies, depending upon the thickness, but in general may be set within 20 to 800mJ / cm ^2, preferably in the range of 20 to a range of 600mJ / cm ^2.

Examples of the developing method include a dipping method, a shower method, a spraying method, a brushing method and the like. As the developing solution, an aqueous alkali solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, .

The alkali-developable photosensitive resin composition of the present invention is suitable for forming a cured coating film such as a solder resist or an interlayer insulating layer of a printed wiring board or a flexible printed wiring board.

[Example]

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is by no means limited by these examples and comparative examples. Unless otherwise stated, " part " means mass part and "% " means mass%.

(Preparation of carboxyl group-containing resin)

[Production Example 1]

220 parts (1 equivalent) of cresol novolac epoxy resin (EOCN-104S, epoxy equivalent 220 g / eq, manufactured by Nippon Kayaku Co., Ltd.), 140.1 parts of carbitol acetate and 60.3 parts of solvent naphtha were charged into a flask, Respectively. The obtained solution was once cooled to 60 占 폚, and 72 parts (1 mole) of acrylic acid, 0.5 part of methylhydroquinone and 2 parts of triphenylphosphine were added and heated to 100 占 폚 for about 12 hours to give an acid value of 0.2 mgKOH / g Was obtained. Thereto was added 80.6 parts (0.53 mol) of tetrahydrophthalic anhydride, heated to 90 占 폚, and reacted for about 6 hours to obtain a resin solution having a solid acid value of 80 mgKOH / g and a solid content concentration of 65%. Hereinafter, it is referred to as a varnish A-1.

[Production Example 2]

313 parts of bisphenol A and 987 parts of bisphenol A type epoxy resin (Epiclon 840, manufactured by DIC, epoxy equivalent: 180) were fed into a flask equipped with a stirrer, a stirrer, a cooling tube and a thermometer, And dissolved at 120 ° C. Thereafter, 0.65 part of triphenylphosphine was added, the temperature in the flask was raised to 150 ° C, and the reaction was carried out for about 90 minutes while maintaining the temperature at 150 ° C to obtain an epoxy compound having an epoxy equivalent of 475 g / eq. Subsequently, the temperature in the flask was lowered to 70 DEG C or lower, 1851 parts of epichlorohydrin and 1690 parts of dimethyl sulfoxide were added, and the mixture was heated to 70 DEG C with stirring to be maintained. Thereafter, 110 parts of 96% sodium hydroxide was added in portions over 90 minutes, and the mixture was further reacted for 3 hours. After completion of the reaction, most of the excess epichlorohydrin and dimethyl sulfoxide were distilled at 120 DEG C under a reduced pressure of 50 mmHg, and the reaction product containing the by-product salt and dimethylsulfoxide was dissolved in methyl isobutyl ketone and washed with water.

Thereafter, methyl isobutyl ketone was distilled and collected from the oil layer to obtain a polynuclear epoxy compound having an epoxy equivalent of 336 g / eq. Subsequently, 336 parts of the above polycyclic epoxy compound was placed in a flask equipped with a stirrer, a cooling tube and a thermometer, 300 parts of carbitol acetate was added and heated to dissolve. Then, 0.46 part of methylhydroquinone and 1.38 parts of triphenylphosphine were added, Deg.] C, and 72 parts of acrylic acid was slowly added dropwise, followed by reaction for 16 hours. The reaction product was cooled to 80 to 90 占 폚, and 152 parts of tetrahydrophthalic anhydride was added. The reaction product was reacted for 8 hours, cooled, and then taken out. The carboxyl group-containing photosensitive resin varnish thus obtained had a nonvolatile content of 64.9% and an acid value of 98 mgKOH / g. Hereinafter, the obtained resin varnish is referred to as varnish A-2.

[Examples 1 to 9, Comparative Examples 1 to 4]

The above varnish was compounded with various components shown in Table 1 in the ratio shown in Table 1 (parts by mass), preliminarily mixed with a stirrer, and kneaded by a three-roll mill to prepare an alkali developing photosensitive resin composition.

≪ Preparation of evaluation substrate &

Each of the alkali-developable photosensitive resin compositions obtained in the above-mentioned Examples and Comparative Examples was applied on the entire surface of the substrate so as to have a thickness of 20 mu m after being dried by screen printing, and dried in a hot-air circulation type drying furnace at 80 DEG C for 30 minutes Thereafter, it was left to cool to room temperature. The substrate was exposed at an optimum exposure dose using a high-pressure mercury lamp mounted exposure apparatus (mercury short arc lamp exposure apparatus, Oak Seascusa Co., Ltd.)) at a temperature of 30 占 폚, spray pressure of 0.2 MPa, developer: 1 mass% And developed for 60 seconds under the conditions to obtain a pattern. The substrate was irradiated with ultraviolet rays under the conditions of an integrated exposure dose of 1000 mJ / cm ² in a UV conveyer, and then heated at 160 캜 for 60 minutes to be cured to obtain a printed substrate (evaluation substrate). The optimum exposure amount was exposed through a step tablet (T4105C, manufactured by Stouffer Co., Ltd.) at the time of exposure, and when the number of step tablets remaining after development was eight, the optimum exposure amount was obtained.

<Touch-up Drying>

Each of the alkali-developable photosensitive resin compositions obtained in the above-mentioned Examples and Comparative Examples was coated on the entire surface by screen printing on the patterned copper-clad substrate, and dried in a hot-air circulation type drying furnace at 80 캜 for 30 minutes. The PET film was pressed on the substrate, and then the film was peeled off when the negative film was peeled off. The results are shown in Table 1 below.

○: There is no resistance when peeling off the film, and no marks are left on the film.

△: There is a little resistance when peeling off the film, and a few marks are left on the film.

X: There is resistance when peeling off the film, and marks are clearly left on the film.

<Developability>

In the preparation of the evaluation substrate, the drying condition after the formation of the coating film was changed to 80 캜 for 90 minutes and dried, and the film thickness condition after drying was 20 탆, and the state of removal of the coating film on the unexposed portion after development was visually confirmed . The evaluation criteria are as follows. The results are shown in Table 1 below.

○: No residue at all.

B: Some filler residue is visible on the surface.

X: Entirely with development residue.

<Outgas>

The alkali-developable photosensitive resin compositions of each of the above-mentioned Examples and Comparative Examples obtained above were coated on the entire surface of the copper-clad board with pattern printing by screen printing and dried at 80 ° C for 20 minutes. Subsequently, the substrate was exposed through a photomask using an exposure apparatus equipped with a metal halide lamp, and developed with a 1 mass% Na ₂ CO ₃ aqueous solution having a spray pressure of 0.2 MPa at 30 ° C to form a resist pattern. A powder sample was taken from the prepared resist into a heating / desorizing device (TDU) manufactured by Gerstel. Thereafter, the outgas component was collected at -60 캜 using liquid nitrogen at a heat extraction temperature of 150 캜 for 10 minutes. The captured outgas components were separated and analyzed by a gas chromatography mass spectrometer (6890N / 5973N) manufactured by Agilent Technologies, quantified as n-dodecane conversion, and evaluated by the following criteria.

○: There is almost no outgass component.

△: Out gas component is confirmed a little.

X: Large amount of outgas components.

<Undercut>

In the preparation of the evaluation substrate, a line pattern of each of the alkali-developable photosensitive resin compositions obtained in each of the above-described Examples and Comparative Examples was prepared using a negative pattern having a line width of 100 mu m as a negative mask for evaluation. The sectional shapes of the obtained lines were observed with an optical microscope and evaluated. The results are shown in Table 1 below.

A: The cross-sectional shape is substantially rectangular.

△: Some protrusion and undercut were confirmed.

X: Large protrusions and undercuts, apparently reverse trapezoidal.

* 1: Photosensitive carboxyl group-containing resin having cresol novolak skeleton (CN (cresol novolak type epoxy resin / AA (acrylic acid) / THPA (tetrahydrophthalic anhydride))

* 2: Photosensitive carboxyl group-containing resin having bisphenol A type skeleton (BISA (Bisphenol A type epoxy resin / AA (acrylic acid) / THPA (tetrahydrophthalic anhydride))

* 3: Bisacylphosphine oxide photopolymerization initiator, Irgacure 819 (bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide) manufactured by BASF Japan Co.,

* 4: Monoacyl phosphine oxide photopolymerization initiator, Lucifer TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide) manufactured by BASF Japan Co.,

* 5:? -Aminoalkylphenon-based photopolymerization initiator, Irgacure 907 (2-methyl-1- (4-methylthiophenyl)

* 6: Thioxanthene photopolymerization initiator, DETX-S (2,4-diethylthioxanthone) manufactured by Nippon Kayaku Co.,

* 7: Admatech SO-E2 manufactured by Adma Tech Co., Ltd.

* 8: B-30 manufactured by Sakai Chemical Industry Co., Ltd.

* 9: Diethylene glycol monoethyl ether acetate

* 10: Aromatic hydrocarbons (Solvesso 150)

* 11: bisphenol A novolak type epoxy resin, jER157S (epoxy equivalent: 200 to 220) manufactured by Mitsubishi Chemical Corporation,

* 12: biphenyl-type epoxy resin, YX-4000 manufactured by Mitsubishi Chemical Corporation

* 13: Bisphenol A type epoxy resin, jER828 manufactured by Mitsubishi Chemical Corporation

* 14: Cresol novolak type epoxy resin, RN695 manufactured by DIC Corporation

* 15: Dipentaerythritol hexaacrylate

From the results shown in the above Table 1, it was found that the occurrence of outgas was small in the alkali-developable photosensitive resin compositions of Examples 1 to 9, and it also had touch-dryness and developability. On the other hand, Comparative Example 1, which did not contain an acylphosphine oxide-based photopolymerization initiator, produced a large amount of outgas. Further, Comparative Examples 2 to 4, which did not contain a bisphenol A novolak type epoxy resin, produced a large amount of outgas, a poor touch-to-dry composition, and poor developability.

Claims (6)

An alkali developing photosensitive resin composition comprising (A) a carboxyl group-containing resin, (B) a photopolymerization initiator, (C) an epoxy resin, (D) a (meth) acrylic monomer, and (E)
(B) an acylphosphine oxide-based photopolymerization initiator as a photopolymerization initiator, (C) a bisphenol A novolak type epoxy resin as an epoxy resin, (E) a spherical silica in an amount of 100 parts by mass per 100 parts by mass of the carboxyl- (E) the spherical silica has an average particle diameter (D50) of 0.1 to 5 占 퐉,
As the carboxyl group-containing resin (A)
(1) a photosensitive carboxyl group-containing resin obtained by reacting a (meth) acrylic acid with a cresol novolak type epoxy resin and adding a dibasic acid anhydride to the hydroxyl group present in the side chain,
(2) a photosensitive carboxyl-containing resin obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in a molecule with an alkylene oxide, with a monocarboxylic acid containing an unsaturated group, and reacting the resulting reaction product with a polybasic acid anhydride ,
(3) a photosensitive carboxyl group obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in a molecule with a cyclic carbonate compound, with a monocarboxylic acid containing an unsaturated group, and reacting the obtained reaction product with a polybasic acid anhydride Containing resin
Wherein the alkali-developing photosensitive resin composition contains at least one member selected from the group consisting of alkali metal, alkaline earth metal and alkaline earth metal. delete A dry film obtained by applying and drying the alkali-developable photosensitive resin composition according to claim 1 to a film. The alkali-developable photosensitive resin composition according to claim 1, or a dry film obtained by applying and drying the alkali-developable photosensitive resin composition according to claim 1 to a film and then performing at least one of photo-curing and thermosetting A cured product that features. A printed wiring board having the cured product according to claim 4. delete