JP2019174751A - Photosensitive resin composition - Google Patents

Abstract

An object of the present invention is to provide a photosensitive resin composition capable of obtaining a cured product excellent in blind via hole filling property, film thickness uniformity, and covering property. (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a reactive diluent, (D) an epoxy compound, (E) a non-reactive diluent, Wherein the (E) non-reactive diluent contains a plurality of organic compounds which are in a liquid phase at 25 ° C., and the (E) non-reactive diluent contains 25 ° C. A photosensitive resin composition comprising 10% by mass or more and 60% by mass or less of the organic compound having a surface tension of less than 30.0 mM / m. [Selection diagram] None

Description

  The present invention relates to a photosensitive resin composition used as a coating material for forming a protective film on a coating material, for example, a printed wiring board having a conductor circuit pattern formed on a rigid substrate or a flexible substrate.

  A circuit pattern of a conductor (for example, copper foil) is formed on the printed wiring board, and an electronic component is mounted on the soldering land of the circuit pattern by soldering. The circuit portion excluding the soldering land is used as a protective film. It is covered with an insulating coating. The insulation coating is required to have a uniform coating film, and a non-reactive diluent may be added to the curable resin composition in order to adjust the viscosity of the curable resin composition that is the raw material of the insulation coating. is there.

  Therefore, for example, as a curable resin composition in which a non-reactive diluent is blended, for example, (meth) acrylamide urethane oligomer (A) 0.5 to 30.0 mass%, N-substituted (meth) acrylamide ( B) An active energy ray-curable resin composition containing 10.0 to 69.0% by mass and non-reactive diluent (C) 1.0 to 80.0% by mass has been proposed (Patent Document 1). .

  On the other hand, the printed wiring board may have blind via holes that are non-through holes. Even if blind via holes are formed on the printed wiring board, the insulating coating reliably fills the blind via holes, has excellent wettability of the coating, has a uniform film thickness, and excludes soldering lands. It is required that the part is sufficiently covered.

  However, in the conventional photosensitive resin composition such as Patent Document 1, the blind via hole filling property is not sufficiently obtained, the wettability of the coating film is not sufficient, and the coating film thickness uniformity and the soldering land There was room for improvement in sufficiently covering the circuit part except for (covering property).

JP 2016-113518 A

  In view of the above circumstances, an object of the present invention is to provide a photosensitive resin composition capable of obtaining a cured product excellent in blind via hole filling property, film thickness uniformity, and covering property.

  Aspects of the present invention include (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a reactive diluent, (D) an epoxy compound, and (E) a non-reactive diluent. And (E) the non-reactive diluent includes a plurality of organic compounds that are in a liquid phase at 25 ° C., and the (E) non-reactive diluent includes: A photosensitive resin composition comprising 10% by mass or more and 60% by mass or less of the organic compound having a surface tension at 25 ° C. of less than 30.0 mM / m.

  An aspect of the present invention is a photosensitive resin composition comprising 10% by mass or more and 60% by mass or less of the organic compound having a surface tension at 25 ° C. of less than 28.0 mM / m in the non-reactive diluent (E). is there.

  The aspect of this invention is the photosensitive resin composition in which the said organic compound whose surface tension in 25 degreeC is less than 30.0 mM / m contains diethylene glycol diethyl ether and / or dipropylene glycol monomethyl ether.

  The aspect of this invention is the photosensitive resin composition which contains the said (E) non-reactive diluent 20-30 mass%.

  An aspect of the present invention is a photosensitive resin composition containing 80 parts by mass or more and 120 parts by mass or less of the (E) non-reactive diluent with respect to 100 parts by mass of the (A) carboxyl group-containing photosensitive resin.

  According to the aspect of the present invention, (E) the non-reactive diluent contains 10% by mass to 60% by mass of an organic compound having a surface tension at 25 ° C. of less than 30.0 mM / m, thereby filling the blind via hole. It can be set as the photosensitive resin composition which can obtain the hardened | cured material excellent in property, film thickness uniformity, and covering property.

  According to the aspect of the present invention, when the organic compound having a surface tension at 25 ° C. of less than 30.0 mM / m contains diethylene glycol diethyl ether and / or dipropylene glycol monomethyl ether, blind via hole filling property and uniform film thickness are achieved. The cured product of the photosensitive resin composition that is further excellent in the properties and covering properties can be obtained.

  Next, the photosensitive resin composition of the present invention will be described in detail. The photosensitive resin composition of the present invention comprises (A) a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a reactive diluent, (D) an epoxy compound, and (E) non-photosensitive material. And (E) non-reactive diluent, wherein the (E) non-reactive diluent includes a plurality of organic compounds that are in a liquid phase at 25 ° C. 10 mass% or more and 60 mass% or less of the said organic compound whose surface tension in 25 degreeC is less than 30.0 mM / m is contained in an agent.

(A) Carboxyl group-containing photosensitive resin The chemical structure of the carboxyl group-containing photosensitive resin is not particularly limited as long as it is a photosensitive resin having a free carboxyl group. A resin having one or more bonds is exemplified. As a carboxyl group-containing photosensitive resin, for example, at least part of the epoxy group of a polyfunctional epoxy resin having two or more epoxy groups in one molecule, acrylic acid or methacrylic acid (hereinafter referred to as “(meth) acrylic acid”) A radical polymerizable unsaturated monocarboxylic acid such as epoxy (meth) acrylate to obtain a radical polymerizable unsaturated monocarboxylic oxide epoxy resin, and a polybasic acid or Mention may be made of polybasic acid-modified radical-polymerizable unsaturated monocarboxylic oxide epoxy resins such as polybasic acid-modified epoxy (meth) acrylates obtained by reacting basic acid anhydrides.

  As long as the polyfunctional epoxy resin is a bifunctional or higher functional epoxy resin, its chemical structure is not particularly limited. The epoxy equivalent of the polyfunctional epoxy resin is not particularly limited, but the upper limit is preferably 3000 g / eq, more preferably 1000 g / eq, and particularly preferably 500 g / eq. On the other hand, the lower limit of the epoxy equivalent of the polyfunctional epoxy resin is preferably 100 g / eq, particularly preferably 200 g / eq.

  Examples of multifunctional epoxy resins include biphenyl aralkyl type epoxy resins, phenyl aralkyl type epoxy resins, biphenyl type epoxy resins, naphthalene type epoxy resins, dicyclopentadiene type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins. , Phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, cycloaliphatic polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, glycidylamine type polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin Examples thereof include a resin, a bisphenol-modified novolac epoxy resin, and a polyfunctional modified novolac epoxy resin. These epoxy resins may be used alone or in combination of two or more.

  The radically polymerizable unsaturated monocarboxylic acid is not particularly limited, and examples thereof include (meth) acrylic acid, crotonic acid, cinnamic acid and the like. These radically polymerizable unsaturated monocarboxylic acids may be used alone or in combination of two or more.

  The reaction method of the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid is not particularly limited. For example, the reaction can be performed by heat-treating the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid in an appropriate organic solvent. Can be made.

  The polybasic acid or polybasic acid anhydride is for introducing a free carboxyl group into the photosensitive resin by reacting with the hydroxyl group generated by the reaction of the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid. It is. By introducing a free carboxyl group into the photosensitive resin, alkali developability is imparted to the photosensitive resin. The polybasic acid or polybasic acid anhydride is not particularly limited, and examples of the polybasic acid include succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, trimellitic acid, pyromellitic acid, diglycolic acid, etc. Examples of acid anhydrides include these anhydridesThese compounds may be used alone or in combination of two or more. The reaction method of the radically polymerizable unsaturated monocarboxylic oxide epoxy resin and the polybasic acid or polybasic acid anhydride is not particularly limited. For example, the radical polymerizable unsaturated monocarboxylic oxide epoxy resin and the polybasic acid or polybasic The acid anhydride can be reacted by heat treatment in a suitable organic solvent.

  In the present invention, the above-mentioned polybasic acid-modified radical polymerizable unsaturated monocarboxylic oxide epoxy resin can also be used as a carboxyl group-containing photosensitive resin, but if necessary, the polybasic acid-modified radical polymerizable unsaturated monocarboxylic acid is used. A radically polymerizable unsaturated group is further introduced into the carboxyl group-containing photosensitive resin by addition reaction of a glycidyl compound having one or more radically polymerizable unsaturated groups and an epoxy group to the carboxyl group of the oxidized epoxy resin. Alternatively, a carboxyl group-containing photosensitive resin with improved photosensitivity may be used.

  In this carboxyl group-containing photosensitive resin with improved photosensitivity, the radical polymerizable unsaturated group is added to the side chain of the polybasic acid-modified radical polymerizable unsaturated monocarboxylic oxide epoxy resin skeleton by the reaction of the glycidyl compound. Since they are bonded, the photopolymerization reactivity is high, and more excellent photosensitive characteristics can be exhibited. Examples of the compound having one or more radically polymerizable unsaturated groups and an epoxy group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, pentaerythritol triacrylate monoglycidyl ether, pentaerythritol trimethacrylate monoglycidyl ether, and the like. Can be mentioned. The above-mentioned compound having one or more radically polymerizable unsaturated groups and an epoxy group may be used alone or in combination of two or more.

  The acid value of the carboxyl group-containing photosensitive resin is not particularly limited, but the lower limit is preferably 30 mgKOH / g, particularly preferably 40 mgKOH / g, from the viewpoint of obtaining reliable alkali developability. On the other hand, the upper limit of the acid value of the carboxyl group-containing photosensitive resin is preferably 200 mgKOH / g from the viewpoint of preventing dissolution of the exposed portion with an alkaline developer, and the moisture resistance and insulation of the cured product of the carboxyl group-containing photosensitive resin. 150 mgKOH / g is particularly preferable from the viewpoint of preventing the decrease in the temperature.

  The mass average molecular weight of the carboxyl group-containing photosensitive resin is not particularly limited, but the lower limit is preferably 6000, particularly preferably 7000, from the viewpoint of toughness, mechanical strength, and dryness to touch of the cured product. On the other hand, the upper limit value of the weight average molecular weight of the carboxyl group-containing photosensitive resin is preferably 200000, more preferably 100000, and particularly preferably 50000 from the viewpoint of reliably obtaining alkali developability.

  The carboxyl group-containing photosensitive resin may be synthesized in the reaction step using the above raw materials, or a commercially available carboxyl group-containing photosensitive resin may be used. Examples of commercially available carboxyl group-containing photosensitive resins include “SP-4621” (Showa Denko KK), “ZAR-2000”, “ZFR-1122”, “FLX-2089”, “ZCR-1569H”. (Nippon Kayaku Co., Ltd.), “Cyclomer P (ACA) Z-250” (Daicel Ornex Co., Ltd.), and the like. These resins may be used alone or in combination of two or more.

(B) Photoinitiator A photoinitiator is not specifically limited, A well-known thing can be used. Examples of the photopolymerization initiator include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, Benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-methyl-4 '-(methylthio) -2 -Morpholinopropiophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl-1- (4-methylthiophenyl) -2-morpholine Propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone Benzophenone, p-phenylbenzophenone, 4,4'-bis (diethylamino) benzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, P-dimethylaminobenzoic acid ethyl And luster. 1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime)], ethanone 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3 An oxime ester photopolymerization initiator such as -yl] -1- (0-acetyloxime) may be used. These may be used alone or in combination of two or more.

  Content of a photoinitiator is not specifically limited, 5 mass parts-50 mass parts are preferable with respect to 100 mass parts (solid content, hereafter the same) of carboxyl group-containing photosensitive resin, and 10 mass parts-30. Part by mass is particularly preferred.

(C) Reactive Diluent The reactive diluent is, for example, a photopolymerizable monomer and is a compound having at least one polymerizable double bond per molecule, preferably at least two polymerizable double bonds per molecule. The reactive diluent is used for obtaining a cured product having sufficient acid resistance, heat resistance, alkali resistance, etc., by sufficiently photo-curing the photosensitive resin composition. It differs from a non-reactive diluent that does not have photopolymerizability at least in terms of the presence or absence of photopolymerizability.

  A reactive diluent will not be specifically limited if it is the said compound, For example, mono (meth) acrylate monomers, bifunctional or more polyfunctional (meth) acrylate monomers, etc. can be mentioned. Specifically, for example, 2-hydroxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 1,4 -Butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalic acid Neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (Meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate , Tris (acryloxyethyl) isocyanurate, dipentaerythritol hexa (meth) acrylate, urethane (meth) acrylates and the like. These may be used alone or in combination of two or more.

  Content of a reactive diluent is not specifically limited, For example, 5 mass parts-100 mass parts are preferable with respect to 100 mass parts of carboxyl group-containing photosensitive resin, and 10 mass parts-50 mass parts are especially preferable.

(D) Epoxy Compound The epoxy compound is for obtaining a cured coating film having sufficient strength by increasing the crosslinking density of the cured coating film. As an epoxy compound, an epoxy resin can be mentioned, for example. Examples of the epoxy resin include an epoxy resin used for the preparation of the above-described carboxyl group-containing photosensitive resin. Specifically, a biphenyl aralkyl type epoxy resin, a phenyl aralkyl type epoxy resin, a biphenyl type epoxy resin, Naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, cyclic aliphatic polyfunctional epoxy resin Glycidyl ester type polyfunctional epoxy resin, glycidyl amine type polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol-modified novolac type epoxy resin, polyfunctional modified novolak type Carboxymethyl resins and the like. These epoxy resins may be used alone or in combination of two or more.

  Although content of an epoxy compound is not specifically limited, 10-70 mass with respect to 100 mass parts of carboxyl group-containing photosensitive resin from the point which prevents a photosensitive fall, obtaining the coating film of sufficient intensity | strength after hardening. Part is preferable, and 20 to 60 parts by mass is particularly preferable.

(E) Non-reactive diluent A non-reactive diluent is a mixture containing a plurality of non-reactive diluents that are in a liquid phase at 25 ° C, and the non-reactive diluent has a surface tension at 25 ° C. A non-reactive diluent of less than 30.0 mM / m is contained in an amount of 10% by mass to 60% by mass. The non-reactive diluent contains 10% by mass or more and 60% by mass or less of a reactive diluent having a surface tension at 25 ° C. of less than 30.0 mM / m, so that blind via hole filling property, film thickness uniformity, cover It can be set as the photosensitive resin composition which can obtain the hardened | cured material excellent in ring property.

  The surface tension at 25 ° C. is not particularly limited as long as the surface tension at 25 ° C. of the non-reactive diluent contained in the non-reactive diluent is 10% by mass or more and 60% by mass or less is less than 30.0 mM / m. The tension is preferably less than 29.0 mM / m, and the surface tension at 25 ° C. is particularly preferably less than 28.0 mM / m. For the non-reactive diluent having a surface tension at 25 ° C. of less than 30.0 mM / m, the lower limit of the surface tension is not particularly limited, but is preferably 10.0 mM / m from the viewpoint of coatability. Examples of non-reactive diluents include organic compounds such as organic solvents.

Examples of the organic solvent having a surface tension at 25 ° C. of less than 30.0 mM / m include the following formula (1):
R ¹ —O—R ² —O—R ³ —O—R ⁴ (1)
(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represents an alkyl group having 1 to 3 carbon atoms), and the surface tension is 30.0 mM / Organic compounds less than m, the following formula (2)
HO—R ⁵ —O—R ⁶ —O—R ⁷ (2)
(Wherein R ⁵ , R ⁶ and R ⁷ each independently represents an alkyl group having 1 to 3 carbon atoms), and the surface tension is less than 30.0 mM / m. Compounds are preferred. Of these, diethylene glycol diethyl ether (surface tension 25 mM / m at 25 ° C.) is particularly preferred as the organic compound represented by the formula (1), and dipropylene glycol is preferred as the organic compound represented by the formula (2). Monomethyl ether (surface tension 27.9 mM / m at 25 ° C.) is particularly preferred.

  As described above, the organic compound having a surface tension at 25 ° C. of less than 30.0 mM / m is 10% by mass or more and 60% by mass or less in the total non-reactive diluent (in the total of 100% by mass of the non-reactive diluent). include. When the organic compound having a surface tension at 25 ° C. of less than 30.0 mM / m is less than 10% by mass in the total non-reactive diluent, the blind via hole filling property cannot be obtained, and when it exceeds 60% by mass, the covering property is obtained. Absent. The blending ratio of the organic compound having a surface tension of less than 30.0 mM / m at 25 ° C. is not particularly limited as long as it is 10% by mass or more and 60% by mass or less in the total non-reactive diluent. From the point of improving the film thickness uniformity and covering property in a more balanced manner, the content is preferably 15% by mass to 55% by mass in the total non-reactive diluent, and 20% by mass to 50% by mass in the total non-reactive diluent. % Or less is particularly preferable.

  The blending ratio of the total non-reactive diluent in the photosensitive resin composition is not particularly limited, but the photosensitive resin composition is obtained while obtaining a cured product excellent in blind via hole filling property, film thickness uniformity, and covering property. 10 mass% or more and 100 mass% or less are preferable, 15 mass% or more and 50 mass% or less are more preferable, and 20 mass% or more and 30 mass% or less are especially preferable.

  The content of the total non-reactive diluent is not particularly limited, but the viscosity and drying property of the photosensitive resin composition are appropriately adjusted while obtaining a cured product excellent in blind via hole filling property, film thickness uniformity, and covering property. 40 parts by mass or more and 400 parts by mass or less are preferable, 60 parts by mass or more and 200 parts by mass or less are more preferable, and 80 parts by mass or more and 120 parts by mass or less with respect to 100 parts by mass of the carboxyl group-containing photosensitive resin. Is particularly preferred.

  The balance in the non-reactive diluent is a non-reactive diluent having a surface tension at 25 ° C. of 30.0 mM / m or more. Therefore, the non-reactive diluent contains 40 mass% or more and 90 mass% or less of the non-reactive diluent having a surface tension at 25 ° C. of 30.0 mM / m or more. The non-reactive diluent having a surface tension at 25 ° C. of 30.0 mM / m or more is not particularly limited, and examples thereof include organic compounds such as organic solvents having a surface tension at 25 ° C. of 30.0 mM / m or more. Examples of the organic solvent having a surface tension at 25 ° C. of 30.0 mM / m or more include diethylene glycol monoethyl ether acetate (surface tension 31 mM / m at 25 ° C.) and propylene glycol diacetate (surface tension 31 mM / m at 25 ° C.). And diethylene glycol monoethyl ether (surface tension at 25 ° C., 31 mM / m).

  In the photosensitive resin composition of the present invention, in addition to the above-described components (A) to (E), various components, for example, a colorant, an extender pigment, various additives (for example, curing) Catalyst, organic filler, thixotropic agent, etc.), flame retardant and the like can be appropriately contained.

  The colorant is not particularly limited, such as a pigment, a pigment, and the like, and any color such as a white colorant, a blue colorant, a green colorant, a yellow colorant, a purple colorant, a black colorant, and an orange colorant. Agents can also be used. Examples of the colorant include inorganic colorants such as titanium oxide which is a white colorant, carbon black which is a black colorant, phthalocyanine green which is a green colorant, and phthalocyanine blue and lionol blue which are blue colorants. And phthalocyanine-based organic colorants such as anthraquinone-based colorants such as chromophthal yellow which is a yellow colorant.

  Examples of extender pigments include talc, barium sulfate, hydrophobic silica, alumina, aluminum hydroxide, mica, and urethane beads. Various additives include mercaptobenzoxazal and its derivatives, dicyandiamide (DICY) and its derivatives, melamine and its derivatives, boron trifluoride-amine complex, organic acid hydrazide, diaminomaleonitrile (DAMN) and its derivatives, guanamine And derivatives thereof, amine imide (AI), and curing catalysts such as polyamines. Examples of antifoaming agents include silicones, hydrocarbons, and acrylics.

  The flame retardant is for imparting flame retardancy to the photocured product of the photosensitive resin composition. Examples of the flame retardant include a phosphorus-based flame retardant. Specifically, tris (chloroethyl) phosphate, tris (2,3-dichloropropyl) phosphate, tris (2-chloropropyl) phosphate, tris (2,3-bromopropyl) phosphate, tris (bromochloropropyl) phosphate, Halogen-containing phosphates such as 2,3-dibromopropyl-2,3-chloropropyl phosphate, tris (tribromophenyl) phosphate, tris (dibromophenyl) phosphate, tris (tribromoneopentyl) phosphate; trimethyl phosphate; Non-halogen aliphatic phosphates such as triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate; triphenyl phosphate, cresyl diphenyl phosphate Fate, dicresyl phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, xylenyl diphenyl phosphate, tris (isopropylphenyl) phosphate, isopropylphenyl diphenyl phosphate, diisopropylphenylphenyl phosphate, tris (trimethylphenyl) phosphate, tris (t Non-halogen aromatic phosphates such as -butylphenyl) phosphate, hydroxyphenyldiphenylphosphate, octyldiphenylphosphate; aluminum trisdiethylphosphinate, aluminum trismethylethylphosphinate, aluminum trisdiphenylphosphinate, zinc bisdiethylphosphinate, bis Zinc methylethylphosphinate, bisdiphenyl Metal salts of phosphinic acid such as zinc sphinate, titanyl bisdiethylphosphinate, titanium tetrakisdiethylphosphinate, titanyl bismethylethylphosphinate, titanium tetrakismethylethylphosphinate, titanyl bisdiphenylphosphinate, titanium tetrakisdiphenylphosphinate, 9 , 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylvinylphosphine oxide, triphenylphosphine oxide, trialkylphosphine oxide, phosphine oxide compounds such as tris (hydroxyalkyl) phosphine oxide, etc. It is done. Of these, organophosphates are preferred.

  The method for producing the photosensitive resin composition of the present invention described above is not limited to a specific method. For example, after blending the above components at a predetermined ratio, at room temperature, a kneading means such as a three roll, ball mill, sand mill, or the like. Alternatively, it can be produced by kneading or mixing by a stirring means such as a super mixer or a planetary mixer. Further, prior to the kneading or mixing, if necessary, preliminary kneading or premixing may be performed. Alternatively, (E) after blending at a predetermined ratio other than the non-reactive diluent, kneading or mixing to obtain a resin composition, (E) adding the non-reactive diluent and further kneading or mixing Good.

  Next, an example of how to use the above-described photosensitive resin composition of the present invention will be described. Here, a solder resist film is formed by first coating a photosensitive resin composition of the present invention on a printed wiring board having a circuit pattern formed by etching a copper foil and provided with a blind via hole. This method will be described as an example.

  On the printed wiring board having a circuit pattern formed by etching a copper foil and provided with a blind via hole, the photosensitive resin composition produced as described above is screen printed, spray coater, bar coater, applicator, Using a known method such as a blade coater, knife coater, roll coater, gravure coater, etc., it is applied to a desired thickness and the photosensitive resin composition is filled into the blind via hole. Next, in order to volatilize the non-reactive diluent (for example, organic solvent) in the photosensitive resin composition, preliminary drying is performed by heating at a temperature of about 60 to 90 ° C. for about 15 to 60 minutes. The non-reactive diluent is volatilized from the product to make the surface of the coating film tack-free. On the applied photosensitive resin composition, a negative film having a light-transmitting pattern other than the land of the circuit pattern is brought into close contact, and ultraviolet rays (for example, in a wavelength range of 300 to 400 nm) are irradiated from above. Then, the coating film is developed by removing a non-exposed area corresponding to the land with a dilute alkaline aqueous solution. As the developing method, a spray method, a shower method, or the like is used, and examples of the diluted alkaline aqueous solution used include 0.5 to 5% by mass of an aqueous sodium carbonate solution. Next, it is a cured coating film having a target pattern on a printed wiring board by performing post-cure for 20 to 80 minutes with a hot air circulation dryer at 130 to 170 ° C., and the blind via hole is also a cured coating film. A filled solder resist film can be formed.

  Next, examples of the present invention will be described. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.

Examples 1-6, Comparative Examples 1-3
Each component shown in the following Table 1 other than the non-reactive diluent was blended at the blending ratio shown in the following Table 1, and mixed and dispersed at room temperature using three rolls to prepare a resin composition. Then, the photosensitive resin composition used in Examples 1-6 and Comparative Examples 1-3 is prepared by adding a non-reactive diluent to the obtained resin composition and mixing and dispersing in the same manner as described above. did. Unless otherwise indicated, the compounding quantity of each component shown in following Table 1 shows a mass part. In addition, the blank part of the compounding amount in the following Table 1 means no compounding.

The details of each component in Tables 1 and 2 are as follows.
(A) Carboxyl group-containing photosensitive resin. FLX-2089: solid content (resin content) 65 mass%, diethylene glycol monoethyl ether acetate (surface tension at 25 ° C. is 31 mM / m) 35 mass%. A polybasic acid-modified epoxy acrylate having a structure obtained by reacting acrylic acid with at least a part of the epoxy group of an epoxy resin to obtain an epoxy acrylate, and reacting the produced hydroxyl group with a polybasic acid. Nippon Kayaku Co., Ltd.
(B) Photopolymerization initiator Chemchem DETX: Nippon Siber Hegner Co., Ltd.
・ Irgacure 907: BASF Corporation
(C) Reactive Diluent ・ KRM 8296: Daicel Ornex Co., Ltd.
(D) Epoxy compound EPICRON 860: DIC Corporation

Colorant LIONOL BLUE FG7351: Toyocolor Co., Ltd.
・ Chromophthal Yellow: Ciba Specialty Chemicals Co., Ltd.
Extender pigment, RHC-730 Clear: Dainichi Seika Co., Ltd.
・ Heidilite H-42STV: Showa Denko K.K.
Additive / DICY-7: Mitsubishi Chemical Corporation
・ Melamine: Nissan Chemical Industries, Ltd.
Antifoaming agent, KS-66: Shin-Etsu Chemical Co., Ltd.
Flame Retardant Exolit OP-935: Clariant Japan Co., Ltd.

(E) Non-reactive diluent, Hisolv EDE: Surface tension at 25 ° C is 25 mM / m, Toho Chemical Co., Ltd.
Highsolve DPM: surface tension at 25 ° C is 28 mM / m, Toho Chemical Co., Ltd.
・ EDGAC: Surface tension at 25 ° C is 31 mM / m, Sanyo Chemicals Co., Ltd.

Test piece preparation process Substrate: Substrate provided with a blind via hole portion having a diameter of 100 μm and a depth of 70 μm and a wiring pattern having a conductor thickness of 18 μm Surface treatment: Acid treatment (5 mass% sulfuric acid solution)
Printing method: Screen printing DRY film thickness: 20-23 μm
Pre-drying: 80 ° C., 20 minutes Exposure: 250 mJ / cm ² on the coating film (Oak Manufacturing Co., Ltd., HMW-680GW)
Development: 1% by weight sodium carbonate aqueous solution, development time 60 seconds, spray pressure 0.2 MPa
Post cure: 150 ° C, 30 minutes

Evaluation item (1) Blind via hole filling property Whether or not the photosensitive resin composition is buried in 100 blind via hole portions of the test piece obtained as described above was observed with an optical microscope (× 40 times) and buried. The blind via hole part which is present was calculated and evaluated as follows.
(Double-circle): The blind via hole part is filled in 100 places.
A: 90 to 99 blind via hole portions are filled.
Δ: 80 to 89 blind via hole portions are filled.
X: 79 or less blind via holes are buried.

(2) Film thickness uniformity After sealing and polishing the cross section of the cured coating film between the wiring patterns of the test piece obtained as described above, N = 9 was observed with an optical microscope (× 40 times), The film thickness was measured and evaluated as follows.
○: The maximum and minimum difference in film thickness is less than 3 μm.
Δ: Maximum and minimum difference in film thickness is 3 μm or more and less than 5 μm.
X: The maximum and minimum difference in film thickness is 5 μm or more.

(3) Covering property After sealing and polishing the cross section of the cured coating on the single wiring pattern of the test piece obtained as described above, N = 9 was observed with an optical microscope (× 40 times), The film thickness was measured and evaluated as follows.
○: The film thickness of the cured coating film at the edge portion on the wiring is 15 μm or more.
(Triangle | delta): The film thickness of 10 micrometers or more and less than 15 micrometers of the cured coating film of an edge part on wiring.
X: The film thickness of the cured coating film on the edge portion on the wiring is less than 10 μm.

  The evaluation results are shown in Table 1 below.

  As shown in Table 1, in Examples 1 to 6, in which a non-reactive diluent having a surface tension at 25 ° C. of less than 30 mM / m is contained in 15% to 50% by mass in the total non-reactive diluent, blinds A cured coating film excellent in via hole filling property, film thickness uniformity and covering property could be obtained. In particular, from Examples 4 and 5, when a non-reactive diluent having a surface tension of 25 mM / m at 25 ° C. is blended, it is excellent in blind via hole filling, film thickness uniformity, and covering properties even in a small blending ratio. A cured coating film could be obtained.

  On the other hand, in Comparative Examples 1 and 2 in which the non-reactive diluent having a surface tension at 25 ° C. of less than 30 mM / m is contained in 0 to 8% by mass in the total non-reactive diluent, the blind via hole filling property is increased. In Comparative Example 3 in which the non-reactive diluent having a surface tension at 25 ° C. of less than 30 mM / m was contained in 61% by mass in the total non-reactive diluent, the covering property was not obtained.

  Since the photosensitive resin composition of the present invention can provide a cured product excellent in blind via hole filling property, film thickness uniformity, and covering property, for example, an insulating coating is applied to a printed wiring board having a desired circuit pattern. High utility value in the field to be formed.

Claims (5)

(A) Photosensitive resin containing a carboxyl group-containing photosensitive resin, (B) a photopolymerization initiator, (C) a reactive diluent, (D) an epoxy compound, and (E) a non-reactive diluent. A resin composition comprising:
The (E) non-reactive diluent contains a plurality of organic compounds that are in a liquid phase at 25 ° C., and the surface tension at 25 ° C. is less than 30.0 mM / m in the (E) non-reactive diluent. The photosensitive resin composition which contains the said organic compound 10 mass% or more and 60 mass% or less.   The photosensitive resin composition of Claim 1 which contains the said organic compound whose surface tension in 25 degreeC is less than 28.0 mM / m in the said (E) non-reactive diluent 10 mass% or more and 60 mass% or less.   The photosensitive resin composition according to claim 1 or 2, wherein the organic compound having a surface tension at 25 ° C of less than 30.0 mM / m contains diethylene glycol diethyl ether and / or dipropylene glycol monomethyl ether.   The photosensitive resin composition of any one of Claims 1 thru | or 3 which contains the said (E) non-reactive diluent 20 mass% or more and 30 mass% or less.   The photosensitivity of any one of Claims 1 thru | or 3 which contains 80 to 120 mass parts of said (E) non-reactive diluent with respect to 100 mass parts of said (A) carboxyl group-containing photosensitive resin. Resin composition.