JP6185943B2 - Solder resist composition, coated printed wiring board - Google Patents

Description

  The present invention relates to a solder resist composition and a coated printed wiring board, and in particular, a liquid solder resist composition that is photocurable and developable with an alkaline solution, and a solder resist formed from the solder resist composition The present invention relates to a coated printed wiring board having a layer.

  In recent years, as a method for forming a solder resist layer in a printed wiring board for consumer and industrial use, in order to cope with the higher wiring density of the printed wiring board, it has excellent resolution and can be developed instead of the screen printing method. A method using a liquid solder resist composition has occupied a large position.

  Covering the printed wiring board with a colored solder resist layer, particularly a black solder resist layer, makes it difficult to see the conductor wiring of the printed wiring board. Since this black solder resist layer contains a large amount of a black colorant, there is a problem that the resolution is deteriorated due to light absorption of the black colorant. For example, the black solder resist composition disclosed in Patent Document 1 includes carbon black as a black colorant, and phthalocyanine blue and anthraquinone red as colorants other than black. In the black solder resist composition of Patent Document 1, the use amount of the black colorant is reduced by adding a colorant other than black, whereby the resolution of the solder resist layer formed from the solder resist composition is reduced. We are trying to improve.

JP 2008-257045 A

  However, due to the recent demand for higher wiring density, it is required to achieve both further improvement in resolution and further improvement in concealment of the conductor wiring by the solder resist layer.

  This invention is made | formed in view of said point, and is formed from the soldering resist composition which can form the soldering resist layer provided with required resolution and concealment property, and this soldering resist composition. It aims at providing the covering printed wiring board provided with a soldering resist layer.

The solder resist composition according to the present invention comprises at least one photopolymerizable compound (B) selected from the group consisting of a carboxyl group-containing resin (A), a photopolymerizable monomer and a photopolymerizable prepolymer, a photopolymerization initiator. By containing (C), a thermosetting component (D), a perylene-based black colorant (E1), and a type of colorant (E2) other than black, photocured on a copper plate and then thermally cured. When a film having any thickness dimension included in the range of 18 to 22 μm is formed, the film has an L ^* value of 40 or less and an a ^* value in the range of 5.1 to 55. , B ^* value is in the range of -15-15.

  In the solder resist composition according to the present invention, the colorant (E2) is preferably a red colorant.

  In the solder resist composition according to the present invention, the colorant (E2) is preferably an anthraquinone red colorant.

  In the solder resist composition according to the present invention, it is preferable that the thermosetting component (D) includes a compound having a cyclic ether skeleton.

  In the solder resist composition according to the present invention, the carboxyl group-containing resin (A) is preferably a carboxyl group-containing resin (A2) having a photopolymerizable functional group.

  The coated printed wiring board according to the present invention includes a printed wiring board and a solder resist layer that covers the printed wiring board, and the solder resist layer is formed from the above solder resist composition.

  The coated printed wiring board according to the present invention preferably includes a second resist layer that covers the solder resist layer.

  In the coated printed wiring board according to the present invention, it is preferable that the second resist layer includes a first region and a second region having a light transmittance higher than that of the first region.

  In the coated printed wiring board according to the present invention, it is preferable that the second solder resist layer contains a green colorant.

In the coated printed wiring board according to the present invention, in the second resist layer, the L ^* value of the first region is 35 or more, the a ^* value is −15 or less, and the b ^* value is within the range of −5 to 5. Preferably, the L ^* value of the second region is 32 or less, the a ^* value is in the range of −10 to 10 and the b ^* value is in the range of −5 to 5.

  The solder resist layer formed from the solder resist composition of the present invention has required resolution and concealment.

1A to 1C are cross-sectional views showing an example of the manufacturing process of the coated printed wiring board according to this embodiment. 2A to 2C are cross-sectional views illustrating an example of a manufacturing process of a coated printed wiring board according to another embodiment.

  A mode for carrying out the present invention will be described. In the present specification, acryloyl and / or methacryloyl are represented as (meth) acryloyl. Moreover, acrylate and / or methacrylate are represented as (meth) acrylate. Moreover, acrylic acid and / or methacrylic acid are represented as (meth) acrylic acid.

The solder resist composition comprises one or more photopolymerizable compounds (B) selected from the group consisting of a carboxyl group-containing resin (A), a photopolymerizable monomer and a photopolymerizable prepolymer, a photopolymerization initiator (C), It contains a thermosetting component (D), a perylene-based black colorant (E1), and a kind of colorant (E2) other than black. When a film having any thickness within the range of 18 to 22 μm is formed from this solder resist composition by photocuring on a copper plate and then thermosetting, this film has an L ^* value. Is 40 or less, the a ^* value is in the range of 5.1 to 55, and the b ^* value is in the range of -15 to 15.

Thus, the solder resist composition contains a perylene-based black colorant (E1) and a colorant other than black (E2), and a film formed from this solder resist composition has a specific range of L ^* values, a ^* By having the value and the b ^* value, when the film of the solder resist composition is exposed, the film can be sufficiently cured from the surface layer to the deep part. Thereby, the high resolution and high concealment property of the soldering resist layer formed from a soldering resist composition can be made compatible.

  The solder resist composition according to this embodiment will be described in more detail.

[Carboxyl group-containing resin (A)]
The carboxyl group-containing resin (A) can impart developability with an alkaline solution, that is, alkali developability, to the coating film formed from the solder resist composition.

[Carboxyl group-containing resin (A1) having a carboxyl group and no photopolymerizable functional group]
The carboxyl group-containing resin (A) can contain a carboxyl group-containing resin (A1) (hereinafter also referred to as component (A1)) that has a carboxyl group and does not have a functional group.

  (A1) A component contains the polymer of the ethylenically unsaturated monomer containing the ethylenically unsaturated compound which has a carboxyl group, for example. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group.

  The ethylenically unsaturated compound having a carboxyl group can contain an appropriate polymer and prepolymer, for example, a compound having only one ethylenically unsaturated group. More specifically, ethylenically unsaturated compounds having a carboxyl group are, for example, acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≈2) monoacrylate, crotonic acid, cinnamic acid, 2-acryloyloxyethyl succinate. Acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl phthalic acid, β-carboxyethyl acrylate, acryloyloxyethyl succinate, methacryloyloxyethyl succinate, 2-propenoic acid , 3- (2-Carboxyethoxy) -3-oxypropyl ester, 2-acryloyloxyethyl tetrahydrophthalic acid, 2-methacryloyloxyethyl tetrahydrophthalic acid, 2-acryloyloxyethylhexyl One or more compounds selected from the group consisting of sahydrophthalic acid and 2-methacryloyloxyethyl hexahydrophthalic acid can be contained. The ethylenically unsaturated compound having a carboxyl group can also contain a compound having a plurality of ethylenically unsaturated groups. More specifically, for example, ethylenically unsaturated compounds having a carboxyl group are pentaerythritol triacrylate, pentaerythritol trimethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol. A compound obtained by reacting a dibasic acid anhydride with a polyfunctional (meth) acrylate having a hydroxyl group selected from the group consisting of pentamethacrylate can be contained. These compounds are used individually by 1 type, or multiple types are used together.

  The ethylenically unsaturated compound which does not have a carboxyl group should just be a compound copolymerizable with the ethylenically unsaturated compound which has a carboxyl group. The ethylenically unsaturated compound having no carboxyl group can contain both a compound having an aromatic ring and a compound having no aromatic ring.

  Examples of the compound having an aromatic ring include 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate, 2- (meth) acryloyloxypropyl phthalate, and benzyl (meth). Acrylate, neopentyl glycol benzoate (meth) acrylate, paracumylphenoxyethylene glycol (meth) acrylate, EO-modified cresol (meth) acrylate, ethoxylated phenyl (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate (n = 2 to 2) 17), ECH-modified phenoxy (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxyhexaethylene glycol (meth) Acrylate, phenoxytetraethylene glycol (meth) acrylate, tribromophenyl (meth) acrylate, EO modified tribromophenyl (meth) acrylate, EO modified bisphenol A di (meth) acrylate, PO modified bisphenol A di (meth) acrylate, modified Bisphenol A di (meth) acrylate, EO modified bisphenol F di (meth) acrylate, ECH modified phthalic acid di (meth) acrylate, trimethylolpropane benzoate (meth) acrylate, EO modified phthalic acid (meth) acrylate, EO, PO modified One or more compounds selected from the group consisting of phthalic acid (meth) acrylate, vinyl carbazole, styrene, vinyl naphthalene, and vinyl biphenyl can be contained.

  The compound having no aromatic ring is, for example, a linear or branched aliphatic or alicyclic (however, the ring may partially have an unsaturated bond) (meth) acrylic acid ester, hydroxyalkyl One or more compounds selected from the group consisting of (meth) acrylates, alkoxyalkyl (meth) acrylates, etc .; and N-substituted maleimides such as N-cyclohexylmaleimide can be contained. Compounds that do not have an aromatic ring include ethylene glycol in one molecule such as polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and pentaerythritol tri (meth) acrylate. You may contain the compound which has 2 or more of unsaturated unsaturated groups. These compounds are used individually by 1 type, or multiple types are used together. These compounds are preferable in that the hardness and oiliness of the solder resist layer can be easily adjusted.

  The type, ratio, and the like of the compound used to obtain the component (A1) are appropriately selected so that the acid value of the component (A1) is an appropriate value. The acid value of the component (A1) is preferably in the range of 20 to 180 mgKOH / g, more preferably in the range of 35 to 165 mgKOH / g.

[About carboxyl group-containing resin (A2) having a photopolymerizable functional group]
The carboxyl group-containing resin (A) can also contain a carboxyl group-containing resin (A2) having a photopolymerizable functional group (hereinafter also referred to as component (A2)). The photopolymerizable functional group is, for example, an ethylenically unsaturated group.

  The component (A2) is prepared by reacting, for example, an ethylenically unsaturated compound (a2) having a carboxyl group with at least one of the epoxy groups in the epoxy compound (a1) having two or more epoxy groups in one molecule. And further a resin having a structure to which a compound (a3) selected from the group consisting of at least one selected from polyvalent carboxylic acids and anhydrides is added (hereinafter referred to as first resin (a)). be able to.

  The epoxy compound (a1) is, for example, a cresol novolak type epoxy resin, a phenol novolak type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol A-novolak type epoxy resin, a naphthalene type epoxy resin, a biphenyl type epoxy resin, It may contain at least one compound selected from the group consisting of a polymer of an ethylenically unsaturated compound including a biphenyl aralkyl type epoxy resin, triglycidyl isocyanurate, an alicyclic epoxy resin, and a compound having an epoxy group.

  The epoxy compound (a1) may contain a polymer of an ethylenically unsaturated compound (p) including the compound (p1) having an epoxy group. The ethylenically unsaturated compound (p) used for the synthesis of this polymer may contain only the compound (p1) having an epoxy group, or the compound (p1) having an epoxy group and a compound not having an epoxy group (P2) may be contained.

  The compound (p1) having an epoxy group can contain a compound selected from appropriate polymers and prepolymers. Specifically, the compound (p1) having an epoxy group is an epoxy cyclohexyl derivative of acrylic acid, an epoxy cyclohexyl derivative of methacrylic acid, an alicyclic epoxy derivative of acrylate, an alicyclic epoxy derivative of methacrylate, or β-methylglycidyl acrylate. And one or more compounds selected from the group consisting of β-methylglycidyl methacrylate. In particular, it is preferable that the compound (p1) having an epoxy group contains glycidyl (meth) acrylate which is widely used and easily available.

  The compound (p2) not having an epoxy group may be a compound copolymerizable with the compound (p1) having an epoxy group. Examples of the compound (p2) having no epoxy group include 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate, 2- (meth) acryloyloxypropyl phthalate, Benzyl (meth) acrylate, neopentyl glycol benzoate (meth) acrylate, paracumylphenoxyethylene glycol (meth) acrylate, EO-modified cresol (meth) acrylate, ethoxylated phenyl (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate ( Degree of polymerization n = 2 to 17), ECH-modified phenoxy (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxyhexaeth Glycol (meth) acrylate, phenoxytetraethylene glycol (meth) acrylate, tribromophenyl (meth) acrylate, EO-modified tribromophenyl (meth) acrylate, EO-modified bisphenol A di (meth) acrylate, PO-modified bisphenol A di ( (Meth) acrylate, modified bisphenol A di (meth) acrylate, EO modified bisphenol F di (meth) acrylate, ECH modified phthalic acid di (meth) acrylate, trimethylolpropane benzoate (meth) acrylate, EO modified phthalic acid (meth) acrylate , EO, PO modified phthalic acid (meth) acrylate, vinyl carbazole, styrene, N-phenylmaleimide, N-benzylmaleimide, 3-maleimidobenzoic acid N-succinimid , (Meth) acrylic acid ester, hydroxyalkyl (meth) acrylate, alkoxyalkyl (which may have a linear or branched aliphatic or alicyclic group (but may partially have an unsaturated bond in the ring)) One or more compounds selected from the group consisting of (meth) acrylates and N-substituted maleimides (for example, N-cyclohexylmaleimide) can be contained.

  The compound having no epoxy group (p2) may further contain a compound having two or more ethylenically unsaturated groups in one molecule. This compound is used, and the hardness and oiliness of the solder resist layer are easily adjusted by adjusting the amount of the compound. Examples of the compound having two or more ethylenically unsaturated groups in one molecule include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and pentaerythritol tri (meth). One or more compounds selected from the group consisting of acrylates can be contained.

  A polymer is obtained by polymerizing the ethylenically unsaturated compound (p) by a known polymerization method such as a solution polymerization method or an emulsion polymerization method. Specific examples of the solution polymerization method include a method of heating and stirring the ethylenically unsaturated compound (p) in a suitable organic solvent in the presence of a polymerization initiator in a nitrogen atmosphere and an azeotropic polymerization method.

  Examples of the organic solvent used for the polymerization of the ethylenically unsaturated compound (p) include ketones such as methyl ethyl ketone and cyclohexanone, and aromatic hydrocarbons such as toluene and xylene, and ethyl acetate, butyl acetate, and cellosolve acetate. One or more compounds selected from the group consisting of acetate esters such as butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, and propylene glycol monomethyl ether acetate, and dialkyl glycol ethers can be contained.

  The polymerization initiator used for the polymerization of the ethylenically unsaturated compound (p) is, for example, hydroperoxides such as diisopropylbenzene hydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-di Dialkyl peroxides such as-(t-butylperoxy) -hexane, diacyl peroxides such as isobutyryl peroxide, ketone peroxides such as methyl ethyl ketone peroxide, alkyl peroxides such as t-butyl peroxybivalate , Peroxydicarbonates such as diisopropyl peroxydicarbonate, azo compounds such as azobisisobutyronitrile, and one or more compounds selected from the group consisting of redox initiators.

  The ethylenically unsaturated compound (a2) can contain a compound selected from the group consisting of appropriate polymers and prepolymers. The ethylenically unsaturated compound (a2) can contain a compound having only one ethylenically unsaturated group. Examples of the compound having only one ethylenically unsaturated group include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2 -Methacryloyloxyethylphthalic acid, β-carboxyethyl acrylate, acryloyloxyethyl succinate, methacryloyloxyethyl succinate, 2-propenoic acid, 3- (2-carboxyethoxy) -3-oxypropyl ester, 2-acryloyl Consists of oxyethyl tetrahydrophthalic acid, 2-methacryloyloxyethyl tetrahydrophthalic acid, 2-acryloyloxyethyl hexahydrophthalic acid, and 2-methacryloyloxyethyl hexahydrophthalic acid It can contain one or more compounds selected from. The ethylenically unsaturated compound (a2) can further contain a compound having a plurality of ethylenically unsaturated groups. Compounds having a plurality of ethylenically unsaturated groups are, for example, hydroxyl groups such as pentaerythritol triacrylate, pentaerythritol trimethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, etc. One or more compounds selected from the group consisting of compounds obtained by reacting dibasic acid anhydrides with polyfunctional acrylates and polyfunctional methacrylates can be contained.

  In particular, the ethylenically unsaturated compound (a2) preferably contains at least one of acrylic acid and methacrylic acid. In this case, since the ethylenically unsaturated group derived from acrylic acid and methacrylic acid is particularly excellent in photoreactivity, the photoreactivity of the first resin (a) is increased.

  The amount of the ethylenically unsaturated compound (a2) used is such that the carboxyl group of the ethylenically unsaturated compound (a2) is in the range of 0.4 to 1.2 mol with respect to 1 mol of the epoxy group of the epoxy compound (a1). It is preferable that the amount is such that the carboxyl group is in the range of 0.5 to 1.1 mol.

  The compound (a3) selected from the group consisting of polyvalent carboxylic acids and anhydrides thereof is, for example, phthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, methylnadic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, succinic acid. Dicarboxylic acids such as acid, methylsuccinic acid, maleic acid, citraconic acid, glutaric acid, itaconic acid; cyclohexane-1,2,4-tricarboxylic acid, trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, methylcyclohexenetetracarboxylic acid One or more compounds selected from the group consisting of polybasic carboxylic acids such as tribasic acids and the like; and anhydrides of these polyvalent carboxylic acids.

  The compound (a3) is used mainly for imparting redispersion and resolubility with a dilute alkaline aqueous solution to the solder resist composition by giving an acid value to the first resin (a). The amount of the compound (a3) used is adjusted so that the acid value of the first resin (a) is preferably 30 mgKOH / g or more, particularly preferably 60 mgKOH / g or more. The amount of the compound (a3) used is adjusted so that the acid value of the first resin (a) is preferably 160 mgKOH / g or less, particularly preferably 130 mgKOH / g or less.

  When the first resin (a) is synthesized, an addition reaction between the epoxy compound (a1) and the ethylenically unsaturated compound (a2), and a product (addition reaction product) and a compound (a3) obtained by the addition reaction. In the case of proceeding the addition reaction with (), a known method may be employed. For example, in the addition reaction between the epoxy compound (a1) and the ethylenically unsaturated compound (a2), the ethylenically unsaturated compound (a2) is added to the solvent solution of the epoxy compound (a1), and thermal polymerization is prohibited as necessary. A reactive solution is obtained by adding an agent and a catalyst and stirring and mixing. An addition reaction product is obtained by reacting this reactive solution at a reaction temperature of preferably 60 to 150 ° C., particularly preferably 80 to 120 ° C., by a conventional method. Examples of the thermal polymerization inhibitor include hydroquinone or hydroquinone monomethyl ether. Examples of the catalyst include tertiary amines such as benzyldimethylamine and triethylamine, quaternary ammonium salts such as trimethylbenzylammonium chloride and methyltriethylammonium chloride, triphenylphosphine, and triphenylstibine.

  In proceeding the addition reaction between the addition reaction product and the compound (a3), the compound (a3) is added to the solvent solution of the addition reaction product, and a thermal polymerization inhibitor and a catalyst are further added as necessary, followed by stirring and mixing. By doing so, a reactive solution is obtained. The first resin (a) is obtained by reacting this reactive solution by a conventional method. The reaction conditions may be the same as in the addition reaction of the epoxy compound (a1) and the ethylenically unsaturated compound (a2). As the thermal polymerization inhibitor and the catalyst, the compound used in the addition reaction between the epoxy compound (a1) and the ethylenically unsaturated compound (a2) having a carboxyl group can be used as it is.

  The component (A2) is obtained by reacting an ethylenically unsaturated compound having an epoxy group with a part of a carboxyl group in a polymer of ethylenically unsaturated monomers including an ethylenically unsaturated compound having a carboxyl group. You may contain resin (it is called 2nd resin (b)). The ethylenically unsaturated monomer may contain an ethylenically unsaturated compound having no carboxyl group, if necessary.

  The ethylenically unsaturated compound having a carboxyl group for obtaining the second resin (b) can contain an appropriate polymer and prepolymer. For example, an ethylenically unsaturated compound having a carboxyl group can contain a compound having only one ethylenically unsaturated group. More specifically, ethylenically unsaturated compounds having a carboxyl group are, for example, acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≈2) monoacrylate, crotonic acid, cinnamic acid, 2-acryloyloxyethyl succinate. Acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl phthalic acid, β-carboxyethyl acrylate, acryloyloxyethyl succinate, methacryloyloxyethyl succinate, 2-propenoic acid , 3- (2-Carboxyethoxy) -3-oxypropyl ester, 2-acryloyloxyethyl tetrahydrophthalic acid, 2-methacryloyloxyethyl tetrahydrophthalic acid, 2-acryloyloxyethylhexyl One or more compounds selected from the group consisting of sahydrophthalic acid and 2-methacryloyloxyethyl hexahydrophthalic acid can be contained. The ethylenically unsaturated compound having a carboxyl group can also contain a compound having a plurality of ethylenically unsaturated groups. More specifically, for example, ethylenically unsaturated compounds having a carboxyl group are pentaerythritol triacrylate, pentaerythritol trimethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol. A compound obtained by reacting a dibasic acid anhydride with a polyfunctional (meth) acrylate having a hydroxyl group selected from the group consisting of pentamethacrylate can be contained. These compounds are used individually by 1 type, or multiple types are used together.

  The ethylenically unsaturated compound having no carboxyl group for obtaining the second resin (b) may be any compound that can be copolymerized with the ethylenically unsaturated compound having a carboxyl group. The ethylenically unsaturated compound having no carboxyl group can contain both a compound having an aromatic ring and a compound having no aromatic ring.

  Examples of the compound having an aromatic ring include 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate, 2- (meth) acryloyloxypropyl phthalate, and benzyl (meth). Acrylate, neopentyl glycol benzoate (meth) acrylate, paracumylphenoxyethylene glycol (meth) acrylate, EO-modified cresol (meth) acrylate, ethoxylated phenyl (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate (n = 2 to 2) 17), ECH-modified phenoxy (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxyhexaethylene glycol (meth) Acrylate, phenoxytetraethylene glycol (meth) acrylate, tribromophenyl (meth) acrylate, EO modified tribromophenyl (meth) acrylate, EO modified bisphenol A di (meth) acrylate, PO modified bisphenol A di (meth) acrylate, modified Bisphenol A di (meth) acrylate, EO modified bisphenol F di (meth) acrylate, ECH modified phthalic acid di (meth) acrylate, trimethylolpropane benzoate (meth) acrylate, EO modified phthalic acid (meth) acrylate, EO, PO modified One or more compounds selected from the group consisting of phthalic acid (meth) acrylate, vinyl carbazole, styrene, vinyl naphthalene, and vinyl biphenyl can be contained.

  The compound having no aromatic ring is, for example, a linear or branched aliphatic or alicyclic (however, the ring may partially have an unsaturated bond) (meth) acrylic acid ester, hydroxyalkyl One or more compounds selected from the group consisting of (meth) acrylates, alkoxyalkyl (meth) acrylates, etc .; and N-substituted maleimides such as N-cyclohexylmaleimide can be contained. Compounds that do not have an aromatic ring include ethylene glycol in one molecule such as polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and pentaerythritol tri (meth) acrylate. You may contain the compound which has 2 or more of unsaturated unsaturated groups. These compounds are used individually by 1 type, or multiple types are used together. These compounds are preferable in that the hardness and oiliness of the solder resist layer can be easily adjusted.

  As the ethylenically unsaturated compound having an epoxy group for obtaining the second resin (b), an appropriate polymer or prepolymer may be mentioned. Specific examples of the ethylenically unsaturated compound having an epoxy group include epoxycyclohexyl derivatives of acrylic acid or methacrylic acid; alicyclic epoxy derivatives of acrylate or methacrylate; β-methylglycidyl acrylate, β-methylglycidyl methacrylate, and the like. . These compounds are used individually by 1 type, or multiple types are used together. In particular, it is preferable to use glycidyl (meth) acrylate which is widely used and easily available.

  Component (A2) is an ethylenically unsaturated group in part or all of the hydroxyl group in a polymer of ethylenically unsaturated monomers containing an ethylenically unsaturated compound having a carboxyl group and an ethylenically unsaturated compound having a hydroxyl group. You may contain resin (henceforth 3rd resin (c)) obtained by adding the compound which has a saturated group and an isocyanate group. The ethylenically unsaturated monomer may contain an ethylenically unsaturated compound having no carboxyl group and hydroxyl group, if necessary.

  The ethylenically unsaturated compound having a carboxyl group for obtaining the third resin (c) may be, for example, the same as the ethylenically unsaturated compound having a carboxyl group for obtaining the second resin (b).

  Specific examples of the ethylenically unsaturated compound having a hydroxyl group for obtaining the third resin (c) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meta ) Acrylate, cyclohexanedimethanol mono (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate, caprolactone (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, trimethylol Hydroxyalkyl (meth) acrylates such as propanedi (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, hydroxybutyl vinyl Ether, hydroxyethyl vinyl ether, and N- hydroxyethyl (meth) acrylamide.

  Specific examples of the compound having an ethylenically unsaturated group and an isocyanate group for obtaining the third resin (c) include 2-acryloyloxyethyl isocyanate (as a specific example, Showa Denko KK; product number “Karenz AOI”), 2-Methacryloyloxyethyl isocyanate (specific example Showa Denko KK; product number “Karenz MOI”), methacryloyloxyethoxyethyl isocyanate (specific example Showa Denko KK; product number “Karenz MOI-EG”), Karenz MOI isocyanate block Body (as a specific example Showa Denko KK; product number “Karenz MOI-BM”), Karenz MOI isocyanate block (as a specific example Showa Denko KK; product number “Karenz MOI-BP”), and 1,1- (bis Acryloyloxymethyl) Le isocyanate) (Examples Showa Denko KK; number "Karenz BEI") and the like.

  The weight average molecular weight of the entire component (A2) is preferably in the range of 800 to 100,000. Within this range, particularly excellent photosensitivity and resolution are imparted to the solder resist composition.

  The acid value of the entire component (A2) is preferably 30 mgKOH / g or more. In this case, good developability is imparted to the solder resist composition. The acid value is more preferably 60 mgKOH / g or more. The acid value of the entire component (A2) is preferably 160 mgKOH / g or less. In this case, the residual amount of carboxyl groups in the coating formed from the solder resist composition is reduced, and the coating has good electrical properties. In addition, electric corrosion resistance and water resistance are maintained. The acid value is more preferably 130 mgKOH / g or less.

[About Photopolymerizable Compound (B)]
The photopolymerizable compound (B) imparts photocurability to the solder resist composition. The photopolymerizable compound (B) contains one or more compounds selected from the group consisting of a photopolymerizable monomer and a photopolymerizable prepolymer.

  The photopolymerizable monomer has, for example, an ethylenically unsaturated group. Photopolymerizable monomers include, for example, monofunctional (meth) acrylates such as 2-hydroxyethyl (meth) acrylate; and diethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Multifunctional (meth) such as pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ε-caprolactone modified pentaerythritol hexaacrylate One or more compounds selected from the group consisting of acrylates can be contained.

  It is also preferred that the photopolymerizable monomer contains a phosphorus-containing compound (phosphorus-containing photopolymerizable compound). In this case, the flame retardancy of the cured product of the solder resist composition is improved. Phosphorus-containing photopolymerizable compounds include, for example, 2-methacryloyloxyethyl acid phosphate (as specific examples, product number light ester P-1M and light ester P-2M manufactured by Kyoeisha Chemical Co., Ltd.), 2-acryloyloxyethyl acid phosphate ( As specific examples, Kyoeisha Chemical Co., Ltd. product number light acrylate P-1A), diphenyl-2-methacryloyloxyethyl phosphate (as a specific example, product number MR-260 manufactured by Daihachi Kogyo Co., Ltd.), and Showa Polymer Co., Ltd. HFA series (part number HFA-6003, which is an addition reaction product of dipentaerystol hexaacrylate and HCA as a specific example, and part number HFA which is an addition reaction product of HFA-6007, caprolactone-modified dipentaerystol hexaacrylate and HCA) -30 3, and it can contain one or more compounds selected from the group consisting of HFA-6127, etc.).

  Examples of the photopolymerizable prepolymer include a prepolymer obtained by polymerizing a photopolymerizable monomer, an ethylenically unsaturated group-added prepolymer, an epoxy (meth) acrylate, a polyester (meth) acrylate, and a urethane (meth). Examples thereof include oligo (meth) acrylate prepolymers such as acrylate, alkyd resin (meth) acrylate, silicone resin (meth) acrylate, and spirane resin (meth) acrylate.

[Photopolymerization initiator (C)]
The photopolymerization initiator (C) includes, for example, benzoin and its alkyl ethers; acetophenones such as acetophenone and benzyldimethyl ketal; anthraquinones such as 2-methylanthraquinone; 2,4-dimethylthioxanthone and 2,4-diethylthioxanthone Thioxanthones such as 2-isopropylthioxanthone, 4-isopropylthioxanthone, and 2,4-diisopropylthioxanthone; benzophenones such as benzophenone and 4-benzoyl-4′-methyldiphenyl sulfide; and xanthones such as 2,4-diisopropylxanthone; Compounds containing nitrogen atoms such as 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone; 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy- -Methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- Α-hydroxyalkylphenones such as {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one, phenylglyoxylic acid methyl ester; 2 -Methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino Α-aminoalkylphenones such as) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone; Monoacylphosphine oxide-based photopolymerization initiators such as 2,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4,6-trimethylbenzoyl-ethyl-phenyl-phosphinate; and bis- (2,4,6-trimethylbenzoyl) ) -Phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -4-propylphenylphosphine 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, (2,5,6-trimethylbenzoyl) -2,4,4-trimethylpentyl One or more components selected from the group consisting of acylphosphine photopolymerization initiators such as phosphine oxide can be contained. The photopolymerization initiator (C) includes two or more components selected from the group consisting of α-hydroxyalkylphenones, α-aminoalkylphenones, thioxanthones, and acylphosphine oxide photopolymerization initiators. It is particularly preferable.

[About thermosetting component (D)]
The thermosetting component (D) can impart thermosetting properties to the solder resist composition. In this embodiment, it is preferable that the thermosetting component (D) includes a compound having a cyclic ether skeleton. The compound having a cyclic ether skeleton preferably contains, for example, an epoxy compound.

  The epoxy compound preferably has at least two epoxy groups in one molecule. The epoxy compound may be a poorly solvent-soluble epoxy compound or a general-purpose solvent-soluble epoxy compound. The type of the epoxy compound is not particularly limited. Particularly, the epoxy compound is a phenol novolac type epoxy resin (specifically, product number EPICLON N-775 manufactured by DIC Corporation), or a cresol novolac type epoxy resin (specifically, product number manufactured by DIC Corporation). EPICLON N-695), bisphenol A type epoxy resin (specifically, product number jER1001 manufactured by Mitsubishi Chemical Corporation), bisphenol A-novolak type epoxy resin (specifically, product number EPICLON N-865 manufactured by DIC Corporation), bisphenol F Type epoxy resin (part number jER4004P manufactured by Mitsubishi Chemical Co., Ltd.), bisphenol S type epoxy resin (part number EPICLON EXA-1514 manufactured by DIC Corporation), bisphenol AD type Xi resin, biphenyl type epoxy resin (specifically, product number YX4000 manufactured by Mitsubishi Chemical Corporation), biphenyl novolak type epoxy resin (specifically, product number NC-3000 manufactured by Nippon Kayaku Co., Ltd.), hydrogenated bisphenol A type epoxy resin (Specific examples: Nippon Steel & Sumikin Chemical Co., Ltd. product number ST-4000D), naphthalene type epoxy resins (specific examples: DIC Corporation product numbers EPICLON HP-4032, EPICLON HP-4700, EPICLON HP-4770), hydroquinone type epoxy Resin (part number YDC-1312 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), tertiary butylcatechol type epoxy resin (part number EPICLON HP-820 manufactured by DIC Corporation), dicyclopentadiene type epoxy resin (tool) For example, DIC product number EPICLON HP-7200), adamantane type epoxy resin (specific example: Idemitsu Kosan Co., Ltd. product number ADAMANTATE X-E-201), biphenyl ether type epoxy resin (specific example, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) Product number YSLV-80DE, special bifunctional epoxy resin (as specific examples, product numbers YL7175-500 and YL7175-1000 manufactured by Mitsubishi Chemical Corporation; product numbers EPICLON TSR-960, EPICLON TER-601, EPICLON manufactured by DIC Corporation) TSR-250-80BX, EPICLON 1650-75MPX, EPICLON EXA-4850, EPICLON EXA-4816, EPICLON EXA-4822, and EPICLON EXA-972 6; Nippon Steel & Sumikin Chemical Co., Ltd., product number YSLV-120TE), and preferably one or more components selected from the group consisting of bisphenol-based epoxy resins other than those described above.

  It is also preferred that the epoxy compound contains triglycidyl isocyanurate. The triglycidyl isocyanurate is preferably a β-form having a structure in which three epoxy groups are bonded in the same direction with respect to the S-triazine ring skeleton plane, or 1 for the β-form and the S-triazine ring skeleton plane. A mixture with an α-isomer having a structure in which one epoxy group is bonded to a different direction from the other two epoxy groups is preferable.

[Colorant (E)]
The solder resist composition of this embodiment contains a colorant (E). The colorant (E) contains a perylene black colorant (E1) and a kind of colorant (E2) other than black. Since the solder resist composition contains not only the perylene-based black colorant (E1) but also the colorant (E2), the film is exposed from the surface layer when the film formed from the solder resist composition is exposed. While being able to fully harden to a deep part, the concealability of the conductor wiring by the film formed from this soldering resist composition can fully be ensured.

  In particular, the colorant (E) preferably contains only the perylene-based black colorant (E1) and the colorant (E2). By combining the perylene-based black colorant (E1) and the colorant (E2) in this way, it is possible to suppress a decrease in photocurability of the solder resist composition and to impart high concealability to the coating. Can do.

[Perylene black colorant (E1)]
The perylene-based black colorant (E1) contains, for example, one or more components selected from the group consisting of a color index (CI) pigment black 31 and a color index (CI) pigment black 32. be able to. In addition to the above components, the perylene-based black colorant (E1) does not have a color index number, but BASF's Lumogen Black FK 4280 and Lumogen Black FK are known as perylene-based near-infrared transmitting black colorants. At least one of 4281 can be contained.

[About one kind of colorant (E2) other than black]
The colorant (E2) is, for example, a non-black colorant among known colorants having a color index (CI; issued by The Society of Dyer's and Colorists) number. I just need it. The colorant (E2) is, for example, from the group consisting of a red colorant, a blue colorant, a green colorant, a yellow colorant, a purple colorant, an orange colorant, a brown colorant, and a colorant having a color other than those described above. A kind of colorant selected.

  The colorant (E2) is preferably a red colorant. When the solder resist composition contains a perylene-based black colorant (E1) and a red colorant, when the film formed from this solder resist composition is exposed, the film is sufficiently cured from the surface layer to the deep part. In addition, the concealability of the conductor wiring by the film formed from the solder resist composition can be more easily ensured. The red colorant can contain, for example, one or more components selected from the group consisting of an anthraquinone red pigment, an azo red pigment, a lake red pigment, a quinacridone red pigment, and a diketopyrrole red pigment.

  The red colorant is particularly preferably an anthraquinone red pigment. Anthraquinone red pigments include, for example, Color Index (CI) Pigment Red 83, Color Index (CI) Pigment Red 168, Color Index (CI) Pigment Red 177, and Color Index (C.I.). I.) What is represented by pigment red 216 is mentioned. When the red colorant is an anthraquinone-based red colorant, it is particularly easy to ensure the concealability of the conductor wiring by the film formed from the solder resist composition. Moreover, it is excellent in dispersibility and weather resistance.

[About Colorant (E3)]
The colorant (E) may further contain a colorant (E3) other than the colorant (E1) and the colorant (E2). That is, the colorant (E3) may be contained in the solder resist composition.

  The colorant (E3) is, for example, from the group consisting of a red colorant, a blue colorant, a green colorant, a yellow colorant, a purple colorant, an orange colorant, a brown colorant, and a colorant of a color other than those described above. One or more colorants selected. The colorant (E3) is particularly preferably at least one colorant selected from the group consisting of a red colorant, a purple colorant, an orange colorant, and a brown colorant.

[Other ingredients]
The solder resist composition may contain an organic solvent. The organic solvent is used for the purpose of liquefaction or varnishing of the solder resist composition, viscosity adjustment, application property adjustment, film formation property adjustment, and the like.

  Organic solvents include, for example, linear, branched, secondary or polyhydric alcohols such as ethanol, propyl alcohol, isopropyl alcohol, hexanol and ethylene glycol; ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene Petroleum aromatic mixed solvents such as Swazol series (manufactured by Maruzen Petrochemical Co., Ltd.) and Solvesso series (manufactured by Exxon Chemical Co.); cellosolves such as cellosolve and butylcellosolve; Tolls; propylene glycol alkyl ethers such as propylene glycol methyl ether; polypropylene glycol alkyl ethers such as dipropylene glycol methyl ether; ethyl acetate, butyl acetate, cellosolve acetate, carb Ru 0 may contain as well one or more compounds selected from the group consisting of dialkyl glycol ethers; Lumpur acid esters such as acetate.

  The ratio of the organic solvent in the solder resist composition is adjusted so that when the coating film formed from the solder resist composition is dried, the organic solvent is volatilized quickly, that is, the organic solvent does not remain in the dry film. It is preferred that In particular, the organic solvent is preferably in the range of 5 to 99.5% by mass and more preferably in the range of 15 to 80% by mass with respect to the entire solder resist composition. In addition, since the suitable ratio of an organic solvent changes with application methods etc., it is preferable that a ratio is suitably adjusted according to the application method.

  Unless it deviates from the main point of this invention, the soldering resist composition may further contain components other than the said component.

  For example, the solder resist composition includes tolylene diisocyanate, morpholine diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate blocked isocyanates blocked with caprolactam, oxime, malonic acid ester, etc .; melamine resin, n-butylated melamine Resins, isobutylated melamine resins, butylated urea resins, butylated melamine urea cocondensation resins, benzoguanamine-based cocondensation resins, and other amino resins; various other thermosetting resins; ultraviolet curable epoxy (meth) acrylates; bisphenol A , Phenol novolac, cresol novolac, alicyclic and other epoxy resins obtained by adding (meth) acrylic acid; diallyl phthalate resin, phenoxy resin, urethane resin It may contain one or more resins that are selected from the group consisting of a polymer compound such as a fluorine resin.

  When the solder resist composition contains an epoxy compound, the solder resist composition may further contain a curing agent for curing the epoxy compound. Examples of the curing agent include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- (2 Imidazole derivatives such as -cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, Amine compounds such as 4-methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic hydrazide and sebacic acid hydrazide; phosphorus compounds such as triphenylphosphine; acid anhydrides; phenols; mercaptans; Lewis acid amine complexes; Oni It can contain one or more components selected from the group consisting of unsalted. Examples of commercially available products of these components include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Co., Ltd., U-CAT3503N, U manufactured by San Apro Co., Ltd. -CAT3502T (all are trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof).

  The solder resist composition may contain an adhesion promoter. Examples of the adhesion-imparting agent include guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S-triazine, 2- Examples thereof include S-triazine derivatives such as vinyl-4,6-diamino-S-triazine / isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct.

  Solder resist composition includes curing accelerator; copolymer such as silicone and acrylate; leveling agent; adhesion imparting agent such as silane coupling agent; thixotropic agent; polymerization inhibitor; antihalation agent; flame retardant; An antioxidant; a surfactant; a polymer dispersant; and an inorganic filler such as barium sulfate, crystalline silica, nanosilica, carbon nanotube, talc, bentonite, aluminum hydroxide, magnesium hydroxide, magnesium oxide, and calcium carbonate. You may contain the 1 or more types of component selected from a group.

  The solder resist composition may further contain a known photopolymerization accelerator, sensitizer and the like. For example, the solder resist composition may contain p-dimethylbenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ester, 2-dimethylaminoethylbenzoate and the like.

[About the compounding quantity and preparation method of each component contained in a soldering resist composition]
The amount of the components in the solder resist composition is appropriately adjusted so that the solder resist composition has photocurability and can be developed with an alkaline solution.

  The carboxyl group-containing resin (A) is the sum of the carboxyl group-containing resin (A), the photopolymerizable compound (B), the photopolymerization initiator (C), and the thermosetting component (D) contained in the solder resist composition. On the other hand, it is preferably in the range of 40 to 80% by mass, more preferably in the range of 45 to 75% by mass, and still more preferably in the range of 50 to 70% by mass.

  The photopolymerizable compound (B) is preferably within a range of 5 to 60% by mass and within a range of 10 to 50% by mass with respect to the carboxyl group-containing resin (A) contained in the solder resist composition. More preferably, it is more preferably in the range of 15 to 40% by mass.

  The photopolymerization initiator (C) is preferably in the range of 1 to 50% by mass and in the range of 3 to 40% by mass with respect to the carboxyl group-containing resin (A) contained in the solder resist composition. If it exists, it is more preferable, and if it exists in the range of 5-25 mass%, it is still more preferable.

  The thermosetting component (D) is preferably in the range of 5 to 85% by mass and in the range of 10 to 60% by mass with respect to the carboxyl group-containing resin (A) contained in the solder resist composition. If it exists, it is more preferable if it exists in the range of 15-45 mass%.

  The colorant (E) is preferably in the range of 0.2 to 15% by mass, and in the range of 0.5 to 10% by mass with respect to the carboxyl group-containing resin (A) contained in the solder resist composition. It is more preferable if it is in the range, and it is more preferable if it is in the range of 1 to 8% by mass. When the colorant (E) contained in the solder resist composition is within this range, it is easy to ensure the resolution of the solder resist layer formed from the solder resist composition. When there is too much content of the coloring agent (E) contained in a soldering resist composition, the resolution of the soldering resist layer formed from a soldering resist composition will fall.

  In particular, the perylene-based black colorant (E1) is preferably within a range of 0.1 to 14% by mass with respect to the carboxyl group-containing resin (A) contained in the solder resist composition, and 0.5 to 7 It is more preferable if it is within the range of mass%.

  One type of colorant (E2) other than black is preferably within a range of 0.1 to 12% by mass relative to the carboxyl group-containing resin (A) contained in the solder resist composition, and 0.5 to 7 It is more preferable if it is within the range of mass%. In particular, when the colorant (E2) is a red colorant, it is preferably within a range of 0.5 to 7% by mass with respect to the carboxyl group-containing resin (A) contained in the solder resist composition.

  When the content of the perylene-based black colorant (E1) and the colorant (E2) contained in the solder resist composition is within the above range, when the film of the solder resist composition is cured, from the surface layer of the film It is particularly easy to cure to the deep part, and the concealability of the conductor wiring of the solder resist layer formed from the solder resist composition can be particularly improved.

  Moreover, when a coloring agent (E3) is contained in a soldering resist composition, content of a coloring agent (E3) is 7 mass% or less with respect to carboxyl group-containing resin (A) contained in a soldering resist composition. It is preferable that it is 0.1 mass% or more.

  The raw material which becomes a component of the above solder resist composition is mix | blended and a solder resist composition can be prepared by knead | mixing by the well-known kneading | mixing method using a three roll, a ball mill, a sand mill etc., for example.

When this solder resist composition is photocured on a copper plate and then thermally cured to form a film having any thickness within the range of 18 to 22 μm, the L ^* value of this film is 40 or less, a ^* value is in the range of 5.1 to 55, and b ^* value is in the range of -15 to 15. In addition, if the L ^* value, a ^* value, and b ^* value of a coating having a thickness within a range of 18 to 22 μm satisfy the above conditions, the coating having other thicknesses does not have the above conditions. Also good. For example, if a 20 μm-thick film has the above conditions, an 18 μm film may not have the above conditions. In this case, the concealability of the conductor wiring by the solder resist layer formed from the solder resist composition is sufficiently ensured. The L ^* value, a ^* value, and b ^* value of the coating can be measured by, for example, a spectrocolorimeter. As this spectrocolorimeter, for example, model number CM-600d manufactured by Konica Minolta Sensing Co., Ltd. may be mentioned.

  From the viewpoint of storage stability and the like, the first agent may be prepared by mixing a part of the raw material of the solder resist composition, and the second agent may be prepared by mixing the rest of the raw material. That is, the solder resist composition may include a first agent and a second agent. For example, the first agent is prepared by previously mixing and dispersing the photopolymerizable compound (B), a part of the organic solvent, and the thermosetting component (D) among the raw materials, and the remaining part of the raw materials is mixed. The second agent may be prepared by dispersing it. In this case, the required amount of the first agent and the second agent can be mixed to prepare a mixed solution, and the solder resist layer can be formed from this mixed solution.

[About coated printed wiring boards]
The solder resist composition according to the present embodiment is applied, for example, to form a solder resist layer on a printed wiring board. Thereby, a covering printed wiring board is manufactured.

  Below, an example of the method of forming a soldering resist layer on a printed wiring board using the soldering resist composition by this embodiment is demonstrated, referring FIG. 1A-FIG. 1C. In this example, a solder resist layer is formed from a solder resist composition having both photocurability and thermosetting properties.

  First, a printed wiring board 100 is prepared, and a coating film 1 is formed on the printed wiring board from a solder resist composition. For example, a solder resist composition is applied on the surface of the printed wiring board 100 to form a wet paint film (wet paint film). The method for applying the solder resist composition is selected from the group consisting of known methods such as dipping, spraying, spin coating, roll coating, curtain coating, and screen printing. Subsequently, in order to volatilize the organic solvent in the solder resist composition as necessary, the wet coating film is dried at a temperature in the range of 60 to 120 ° C., for example, and after drying, as shown in FIG. 1A. The coating film 1 (dry coating film) is obtained.

  In forming the coating film 1 on the printed wiring board, the coating film 1 is formed by applying a solder resist composition on an appropriate support in advance and then drying the coating film 1. The coating film 1 may be provided on the printed wiring board 100 by applying pressure to the coating film 1 and the printed wiring board 100 after being stacked on the board 100 (dry film method).

  Subsequently, as shown in FIG. 1B, the mask 3 is applied directly or indirectly to the coating film 1, and then the active energy ray is irradiated toward the mask 3, whereby the coating film 1 is passed through the mask 3. To expose.

  The active energy ray is selected according to the composition of the solder resist composition, but in the present embodiment, it is ultraviolet light. The ultraviolet light source is selected from the group consisting of, for example, a chemical lamp, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, and a metal halide lamp.

  The mask 3 includes an exposure part 31 that transmits active energy rays and a non-exposure part 32 that shields active energy rays. The exposed portion 31 has a shape that matches the pattern shape of the solder resist layer. As this mask, for example, a photo tool such as a mask film or a dry plate is used. When the coating film 1 is exposed through the mask 3, light is irradiated to a portion corresponding to the exposed portion 31 in the coating film 1, and light is irradiated to a portion corresponding to the non-exposed portion 32 in the coating film 1. Not.

  Note that a method other than a method using a mask may be employed as the exposure method. For example, a direct drawing method such as laser exposure may be employed.

  In this embodiment, when the coating film 1 is exposed in this manner, as described above, the photocuring reaction proceeds efficiently from the surface layer to the deep part of the coating film 1.

  After the coating film 1 is exposed, the mask 3 is removed from the printed wiring board 100, and then the coating film 1 is subjected to a development process to remove the unexposed portion of the coating film 1. Then, as shown in FIG. 1C, the exposed portion of the coating film 1 remains as the solder resist layer 10 on the surface of the printed wiring board 100.

  In the development process, an appropriate developer according to the composition of the solder resist composition can be used. Specific examples of the developer include sodium carbonate aqueous solution, potassium carbonate aqueous solution, ammonium carbonate aqueous solution, sodium hydrogen carbonate aqueous solution, potassium hydrogen carbonate aqueous solution, ammonium hydrogen carbonate aqueous solution, sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, ammonium hydroxide aqueous solution, water Examples include alkaline solutions such as tetramethylammonium oxide aqueous solution and lithium hydroxide aqueous solution. As the developer, organic amines such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine can be used. Among these developing solutions, only one type may be used or a plurality of types may be used in combination. When the developer is an alkaline solution, the solvent may be water alone or a mixture of water and a hydrophilic organic solvent such as lower alcohols.

  Since the solder resist composition contains the thermosetting component (D), the solder resist layer can be thermally cured by subjecting the solder resist layer to a heat treatment. The conditions for the heat treatment are, for example, within the range of the heating temperature of 120 to 180 ° C. and within the range of the heating time of 30 to 90 minutes. Thereby, the performance of the solder resist layer such as strength, hardness and chemical resistance is improved.

  Further, after the solder resist layer is subjected to heat treatment, the solder resist layer may be further irradiated with active energy rays. In this case, the photocuring reaction of the solder resist layer can be further advanced. This further improves the migration resistance of the solder resist layer.

  By the above method, a coated printed wiring board including a printed wiring board and a solder resist layer that partially covers the printed wiring board is obtained. The solder resist layer in the coated printed wiring board is sufficiently cured from the surface layer to the deep part.

  The thickness of the solder resist layer is preferably in the range of 5 to 60 μm, for example, and more preferably in the range of 10 to 40 μm. In this case, the concealability of the conductor wiring by the solder resist layer can be improved.

  It is also preferable that this solder resist layer is covered with another solder resist layer (second resist layer). The solder resist layer on the printed wiring board can be protected by this second resist layer.

  Furthermore, it is preferable that the second resist layer includes a first region and a second region having a higher light transmittance than the first region. When the second resist layer includes a plurality of regions having different light transmittances, regions having different colors can be formed. In this case, it is possible to easily mark the second resist layer. For example, the first area is formed into an appropriate figure, character, or the like, whereby the marking by the first area is formed. Moreover, the marking by a 2nd area | region may be formed by forming a 2nd area | region in shapes, such as a suitable figure and a character. For this reason, marking can be performed simultaneously with the formation of the second resist layer.

  Hereinafter, a solder resist composition (hereinafter referred to as a second resist composition) for forming the second resist layer will be described.

  The second resist composition includes a carboxyl group-containing resin (F), a photopolymerizable compound (G), a photopolymerization initiator (H), a colorant (I), and an organic material having a melting point and not having photopolymerizability. Contains compound (J) (hereinafter also referred to as specific organic compound (J)).

  In producing a coated printed wiring board comprising the above solder resist layer and the second resist layer, a second resist composition is applied onto a dried coating film (hereinafter referred to as a first coating film) of the solder resist composition. And drying to form a second coating film, exposing the second coating film, subsequently developing the exposed first coating film and the second coating film with an alkaline solution, and further developing the first coating film And the second coating is heated. Thereby, the covering printed wiring board provided with the soldering resist layer and the 2nd resist layer is manufactured.

  In particular, when exposing the second coating film, the first part of the second coating film is irradiated with active energy rays, and the second part different from the first part of the second coating film is exposed to the first part. The active energy ray is irradiated so that the exposure amount is lower than that of the first portion, and the first region and the third region different from the second portion in the second coating film are not irradiated with the active energy ray.

  The exposure amount in the first portion may be uniform, and a plurality of portions having different exposure amounts may exist in the first portion. Moreover, when irradiating an active energy ray to a 2nd part, the exposure amount in a 2nd part may be uniform, and the some part from which an exposure amount mutually differs may exist in a 2nd part. .

In particular, in order to heat the second coating, the heating temperature of the second coating film, T _h ≧ T _m -30 (where, T _h (° C.) is the heating temperature of the second coating film, T _m is Which is the melting point of the specific organic compound (J). That is, the heating temperature at the time of heating a 2nd coating film is more than the temperature which reduced 30 degreeC from melting | fusing point of the specific organic compound (J). In other words, the melting point of the specific organic compound (J) is equal to or lower than the temperature obtained by adding 30 ° C. to the heating temperature when heating the second coating film.

  When the above conditions are applied when forming the second resist layer, bubbles are formed in the first portion. On the other hand, in the second portion, no bubbles are formed even when heated, or bubbles are formed, but the ratio of the bubbles is lower than that in the first portion. For this reason, the light transmittance of the hardened | cured material (1st area | region) of the 1st part in a 2nd coating film becomes lower than the hardened | cured material (2nd area | region) of a 2nd part. Also, light scattering is more likely to occur in the first region than in the second region.

  For this reason, the appearance color of the first region is the color of the colorant (I) contained in the second resist composition. On the other hand, the appearance color of the second region is a color obtained by mixing the color of the colorant (I) contained in the second resist composition and the color of the surface of the solder resist layer. This effect is presumed to occur for the following reason.

  Since the active energy ray is irradiated at the time of exposure of the 2nd coating film, the 1st part contains the polymer produced | generated by the photopolymerization reaction of the photopolymerizable compound (G). When the second coating film is heated in this state, the specific organic compound (J) in the second coating film is melted so that the second coating film tends to deform, but the first part contains a polymer. Therefore, it is difficult to deform following the melting of the specific organic compound (J). For this reason, it is considered that bubbles are generated in the first portion. On the other hand, the second part does not contain the polymer of the photopolymerizable compound (G), or the ratio of this polymer is lower than that of the first part. For this reason, when a 2nd coating film is heated, compared with a 1st part, a 2nd part tends to deform | transform following a melting | fusing of a specific organic compound (J). For this reason, it is considered that bubbles are not generated in the second portion, or the ratio of bubbles in the second portion is lower than that of the first portion.

  In addition, in this embodiment, even if the heating temperature at the time of heating a 2nd coating film is lower than melting | fusing point of specific organic compound (J), it is more than the temperature which subtracted 30 degreeC from melting | fusing point of specific organic compound (J). If so, bubbles are generated in the first portion. The reason for this is not clearly understood, but the melting point drop (freezing point depression) of the specific organic compound (J) occurs when another compound is mixed into the specific organic compound (J) in the second coating film. Is one of the reasons.

More preferably, the heating temperature of the second coating film after exposure and development satisfies the relationship of T _m + 100 ≧ T _h ≧ T _m −30. In this case, deterioration of the components in the second resist composition due to heat is suppressed.

  The temperature of the second coating film is lower than the melting point of the specific organic compound (J) from the time when the second coating film is formed on the first coating film to the time when the exposure of the second coating film is completed. Is preferably maintained. In this case, the ratio of bubbles in the first region is higher. For this reason, the difference in appearance color between the first region and the second region becomes more prominent. This is because when the specific organic compound (J) melts in the first portion before the photopolymerizable compound (G) in the first portion is polymerized, the specific organic compound (J) For this reason, even if the first part is heated after the exposure of the second coating film, it is assumed that the first part is not easily deformed. More preferably, the temperature of the second coating film is determined from the melting point of the specific organic compound (J) between the time when the second resist composition is placed on the wiring board and the time when the exposure of the second coating film is completed. Maintain a temperature lower than the temperature reduced by 30 ° C.

  This second resist composition will be described in more detail.

[Carboxyl group-containing resin (F)]
The carboxyl group-containing resin (F) can impart developability with an alkaline solution to a coating film formed from the second resist composition. As the carboxyl group-containing resin (F), for example, the same resin as the carboxyl group-containing resin (A) contained in the solder resist composition can be used.

[About Photopolymerizable Compound (G)]
The photopolymerizable compound (G) can impart photocurability to the second resist composition. As the photopolymerizable compound (G), for example, the same photopolymerizable compound (B) as that contained in the solder resist composition can be used.

[About Photoinitiator (H)]
As the photopolymerization initiator (H), for example, the same photopolymerization initiator (C) as that contained in the solder resist composition can be used. In particular, the photopolymerization initiator (H) contained in the second resist composition is selected from the group consisting of α-hydroxyalkylphenones, α-aminoalkylphenones, thioxanthones, and acylphosphine oxide photopolymerization initiators. It is preferable that two or more kinds of components are included.

[Colorant (I)]
The colorant (I) includes, for example, one or more materials selected from the group consisting of pigments, dyes, and pigments. In addition, a coloring agent is a substance which colors the film formed from the composition for film formation. The colorant can include both pigments and dyes. However, a substance which is colored but becomes colorless when heated in the process of producing a film from the film-forming composition is not included in the colorant (I) because it does not color the film.

  The colorant (I) is selected from the group consisting of, for example, a red colorant, a blue colorant, a green colorant, a yellow colorant, a purple colorant, an orange colorant, a brown colorant, and a colorant having a color other than those described above. One or more materials can be included.

  In particular, the colorant (I) preferably contains a green colorant or a mixture of a blue colorant and a yellow colorant. Thereby, the appearance color of the first region in the second resist layer is mainly green, and the appearance color of the second region is a mixed color of the color of the green colorant and the color of the surface of the solder resist layer. Since the first region and the second region have distinctly different appearance colors, the marking formed by the first region and the second region is easy to distinguish. In particular, when the colorant (E2) contained in the solder resist composition is a red pigment and the surface color of the solder resist layer is reddish black, the appearance color of the second region is deep black. In this case, the first region and the second region of the second resist layer have distinctly different appearance colors, so that the marking formed by the first region and the second region is particularly easy to distinguish.

  The green colorant contains, for example, one or more colorants selected from the group consisting of phthalocyanine green colorants, anthraquinone green colorants, perylene green colorants, and metal-substituted or unsubstituted phthalocyanine compounds. Can do. More specific examples of the green colorant include pigment green 7; and a colorant represented by pigment green 36.

[Specific organic compound (J)]
The specific organic compound (J) has a clear melting point and is preferably a low-viscosity liquid above the melting point. It is preferable that melting | fusing point of a specific organic compound (J) exists in the range of 100-230 degreeC. In this case, when the second resist composition is sufficiently exposed and then heated, bubbles are particularly likely to be generated in the cured product of the second resist composition, and bubbles relative to the entire cured product of the second resist composition. The ratio of tends to be high. The specific organic compound (J) can contain, for example, one or more compounds selected from the group consisting of a crystalline epoxy compound and a dicarboxylic acid.

  The crystalline epoxy compound can contain one or more compounds selected from the group consisting of monomers, prepolymers and polymers having an epoxy group and crystallinity. Such compounds are commercially available and are readily available. For example, the crystalline epoxy compound is 1,3,5-tris (2,3-epoxypropyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione (high melting type) Product name YDC-1312 (hydroquinone type crystalline epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Product name YSLV-120TE (thioether type crystalline epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Product name GTR manufactured by Nippon Kayaku Co., Ltd. -1800 (tetrakisphenolethane type crystalline epoxy resin), bisphenolfluorene type crystalline epoxy resin, product name YX-4000 (biphenyl type crystalline epoxy resin) manufactured by Mitsubishi Chemical Corporation, and 1,3,5-tris (2 , 3-epoxypropyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione (low It can contain least one compound selected from the group consisting of a point type).

  The dicarboxylic acid is, for example, one or more selected from the group consisting of malonic acid, succinic acid, adipic acid, oxalic acid, pimelic acid, suberic acid, sebacic acid, phthalic acid, and 4-cyclohexene-1,2-dicarboxylic acid Compounds can be included.

  The specific organic compound (J) may be a compound contained in the photopolymerization initiator (H). Examples of such a compound include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, and ethanone. , 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (0-acetyloxime).

[Other components contained in the second resist composition]
The second resist composition may contain an epoxy compound. The epoxy compound can contain, for example, one or more components selected from the group consisting of a crystalline epoxy compound contained in the specific organic compound (J) and an amorphous epoxy compound.

  Non-crystalline epoxy compounds include, for example, non-crystalline cresol novolac epoxy resin (specifically, product name EPICLON N-695 manufactured by DIC Corporation), non-crystalline phenol novolac epoxy resin (specifically, DIC Corporation). Product name EPICLON N-775), non-crystalline bisphenol A novolac type epoxy resin (specifically, product name EPICLON N-865 manufactured by DIC Corporation), non-crystalline bisphenol A type epoxy resin (specifically Mitsubishi Chemical) Product name jER1001), non-crystalline bisphenol F type epoxy resin (specifically, product name jER4004P manufactured by Mitsubishi Chemical Corporation), non-crystalline bisphenol S type epoxy resin (specifically, product name manufactured by DIC Corporation) EPICLON EXA-15 4) Non-crystalline bisphenol AD type epoxy resin, non-crystalline hydrogenated bisphenol A type epoxy resin, non-crystalline biphenyl novolac type epoxy resin, and non-crystalline special bifunctional type epoxy resin (specific examples) , Mitsubishi Chemical Corporation product numbers YL7175-500 and YL7175-1000; DIC Corporation product names EPICLON TSR-960, EPICLON TER-601, EPICLON TSR-250-80BX, EPICLON 1650-75MPX, EPICLON EXA-4850, EPICLON EXA-4816, EPICLON EXA-4822, and EPICLON EXA-9726; product name YSLV-120T manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and other amorphous bisphenol-based esters It can contain one or more compounds selected from the group consisting of carboxymethyl resin.

  When the second resist composition contains an epoxy compound, the second resist composition preferably contains a curing agent for curing the epoxy compound. Examples of the curing agent include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- (2 Imidazole derivatives such as -cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, Amine compounds such as 4-methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic hydrazide and sebacic acid hydrazide; phosphorus compounds such as triphenylphosphine; acid anhydrides; phenols; mercaptans; Lewis acid amine complexes; Oni It can contain one or more compounds selected from the group consisting of unsalted. Examples of commercially available products of these compounds include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Co., Ltd., U-CAT3503N, U manufactured by San Apro Co., Ltd. -CAT3502T (all are trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof). In addition, the curing agent is guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S, which also functions as an adhesion promoter. -Contains S-triazine derivatives such as triazine, 2-vinyl-4,6-diamino-S-triazine / isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct You can also

  The second resist composition is a known benzoic acid-based or tertiary amine-based photopolymerization accelerator such as p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ester, 2-dimethylaminoethylbenzoate, etc. An agent, a sensitizer and the like may be contained. The second resist composition is a sensitizer for laser exposure, such as 7-diethylamino-4-methylcoumarin, coumarin derivatives such as 4,6-diethyl-7-ethylaminocoumarin, other carbocyanine dyes, xanthene dyes. A system or the like may be contained.

  The second resist composition may contain a filler. In this case, the curing shrinkage of the second coating film is reduced. The filler can contain, for example, one or more materials selected from the group consisting of silica, barium sulfate, carbon nanotubes, aluminum hydroxide, and magnesium hydroxide.

  The second resist composition may further contain an appropriate additive as necessary. For example, the second resist composition includes a copolymer such as silicone and acrylate; a leveling agent; an adhesion-imparting agent such as a silane coupling agent; a thixotropic agent; a polymerization inhibitor; an antihalation agent; a flame retardant; One or more compounds selected from the group consisting of an inhibitor; a surfactant; and a polymer dispersant may be contained.

  The second resist composition may contain an organic solvent. The organic solvent is used for the purpose of liquefaction or varnishing of the second resist composition, viscosity adjustment, coating property adjustment, film forming property adjustment, and the like. As this organic solvent, for example, the same organic solvent as that contained in the above solder resist composition can be used.

  The ratio of the organic solvent in the second resist composition is adjusted so that the organic solvent is volatilized quickly during the preliminary drying of the second coating film, that is, the organic solvent does not remain in the dried second coating film. It is preferable. In particular, the proportion of the organic solvent in the second resist composition is preferably in the range of 5 to 99.5% by mass. In this case, good applicability of the second resist composition can be obtained. In addition, since the suitable ratio of an organic solvent changes with application methods etc., it is preferable that a ratio is suitably adjusted according to the application method.

[About the amount and preparation method of each component contained in the second resist composition]
The amount of the component in the second resist composition is appropriately adjusted so that the second resist composition has photocurability and can be developed with an alkaline solution.

  The carboxyl group-containing resin (F) is preferably in the range of 15 to 55% by mass, more preferably in the range of 20 to 50% by mass, and more preferably in the range of 25 to 45% with respect to the solid content of the second resist composition. If it is in the range of mass%, it is still more preferable.

  The photopolymerizable compound (G) is preferably in the range of 5 to 60% by mass and preferably in the range of 10 to 50% by mass with respect to the carboxyl group-containing resin (F) contained in the second resist composition. More preferably, it is more preferably in the range of 15 to 40% by mass.

  The photopolymerization initiator (H) is preferably in the range of 1 to 50% by mass, and in the range of 3 to 40% by mass with respect to the carboxyl group-containing resin (F) contained in the second resist composition. If it exists, it is more preferable, and if it exists in the range of 5-25 mass%, it is still more preferable.

  The colorant (I) is preferably in the range of 0.2 to 15% by mass, and in the range of 0.5 to 10% by mass with respect to the carboxyl group-containing resin (F) contained in the second resist composition. If it is in, it is more preferable. The green colorant is preferably in the range of 0.2 to 15% by mass and more preferably in the range of 0.5 to 10% by mass with respect to the solid content of the second resist composition.

  The specific organic compound (J) is preferably in the range of 15 to 200% by mass, preferably in the range of 20 to 100% by mass, with respect to the carboxyl group-containing resin (F) contained in the second resist composition. More preferably, it is more preferably in the range of 25 to 80% by mass, and particularly preferably in the range of 30 to 60% by mass.

  The solid content here is the total amount of all components excluding components such as a solvent that volatilizes in the process of forming the second resist layer from the second resist composition.

  The second resist composition can be prepared by blending the above-mentioned raw materials of the second resist composition and kneading by a known kneading method using, for example, a three-roll, ball mill, sand mill or the like.

  In consideration of storage stability and the like, the first agent may be prepared by mixing a part of the raw material of the second resist composition, and the second agent may be prepared by mixing the remainder of the raw material. For example, among the raw materials of the second resist composition, the first agent is prepared by previously mixing and dispersing the photopolymerizable compound (G), a part of the organic solvent, and the specific organic compound (J). The second agent may be prepared by mixing and dispersing the remainder of the raw material of the second resist composition. In this case, the second resist composition can be prepared by mixing the necessary amount of the first agent and the second agent in a timely manner.

  Below, the method to form a 2nd resist layer on a soldering resist layer using the 2nd resist composition of this embodiment is demonstrated with reference to FIG. 2A-FIG. 2C.

  First, a printed wiring board 100 is prepared, and after forming the first coating film 1 from the solder resist composition on the printed wiring board 100 by the above-described method, an organic solvent in the solder resist composition as necessary. In order to volatilize, the wet coating film is dried to obtain a dried first coating film 1 (dry coating film).

  Next, a 2nd resist composition is apply | coated on the 1st coating film 1, and the 2nd coating film 2 is formed as shown to FIG. 2A. The coating method of the second resist composition is selected from the group consisting of known methods such as dipping, spraying, spin coating, roll coating, curtain coating, and screen printing.

  Then, in order to volatilize the organic solvent in a 2nd resist composition as needed, the 2nd coating film 2 is heated (preliminary drying). The heating temperature in this case is preferably a temperature lower than the melting point of the specific organic compound (J) in the second resist composition, and in particular 30 from the melting point of the specific organic compound (J) in the second resist composition. It is preferable that the temperature is lower than the temperature reduced by ° C. This heating temperature is, for example, in the range of 60 to 100 ° C.

  In forming the second coating film 2 on the first coating film 1, a second coating film 2 (dry film) is formed by applying a second resist composition on an appropriate support in advance and then drying. The dry film may be transferred onto the first coating film 1 by applying pressure to the dry film and the first coating film 1 after the dry film is overlaid on the first coating film 1. (Dry film method). In this case, preliminary drying may be omitted.

  Alternatively, after the second resist composition is applied on an appropriate support in advance, the first resist composition is applied and then dried to form a coating comprising two layers of the second coating film 2 and the first coating film 1. A film (dry film) is formed, and this dry film is stacked on the printed wiring board 100, and then the dry film is transferred onto the printed wiring board 100 by applying pressure to the dry film and the printed wiring board 100. Good (dry film method). In this case, preliminary drying may be omitted.

  Subsequently, as shown in FIG. 2B, the mask 4 is applied directly or indirectly to the second coating film 2, and then the active energy ray is irradiated toward the mask 4, thereby allowing the second coating to pass through the mask 4. The film 2 and the first coating film 1 are exposed.

  The active energy ray is selected according to the composition of the solder resist composition and the second resist composition, but in the present embodiment, it is ultraviolet light. The ultraviolet light source is selected from the group consisting of, for example, a chemical lamp, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, and a metal halide lamp.

  The mask 4 includes three types of portions having different degrees of light transmission. For example, the mask 4 includes a light transmissive portion (hereinafter referred to as a transmissive portion 41), a light transmissive portion lower than the transmissive portion 41 (hereinafter referred to as a low transmissive portion 42), and a light transmissive property. A portion (hereinafter referred to as a non-permeable portion 43).

  When the second coating film 2 is exposed through this mask 4, the portion corresponding to the transmissive part 41 (first portion 21) in the second coating film 2 is irradiated with light, and the second coating film 2 is exposed. The portion corresponding to the low-permeability portion 42 (second portion 22) is irradiated with light at an exposure amount lower than that of the first portion 21, and corresponds to the non-permeable portion 43 in the second coating film 2. The portion (third portion 23) is not irradiated with light. The first portion 21 is a portion irradiated with light at the time of exposure, and the second portion 22 is a portion irradiated with light at an exposure amount lower than that of the first portion 21 at the time of exposure. It can also be said that the portion 23 is a portion that is not irradiated with light during exposure. The mask 4 is designed so that the first portion 21, the second portion 22, and the third portion 23 are located at predetermined positions in the second coating film 2.

  When the second coating film 2 is thus exposed, the photopolymerization reaction of the photopolymerizable compound (G) proceeds in the first portion 21 of the second coating film 2, and even in the second portion 22, the first portion Although the degree is lower than 21, the photopolymerization reaction of the photopolymerizable compound (G) proceeds. On the other hand, in the third portion 23, the photopolymerization reaction of the photopolymerizable compound (G) does not proceed.

  Note that the mask 4 as described above may not be used as long as the exposure amounts in the first portion 21, the second portion 22, and the third portion 23 can be controlled to desired values. For example, the second coating 2 is irradiated with light through a mask (first mask) that shields the third portion 23 and does not shield the first portion 21 and the second portion 22, and subsequently A mask (second mask) that shields the second portion 22 and does not shield the first portion 21 is superimposed on the first mask, and further light is transmitted through the first mask and the second mask. It may be irradiated. Even in this case, the first portion 21 is irradiated with light, the second portion 22 is irradiated with light at a lower exposure amount than the first portion 21, and the third portion 23 is irradiated with light. Not irradiated.

The ratio of the exposure amount of the second portion 22 to the exposure amount of the first portion 21 is, for example, in the range of 1 to 75%, and particularly preferably in the range of 1.2 to 60%. Moreover, the exposure amount of the 1st part 21 is in the range of 100-5000 mJ / cm < ² >, for example, and the exposure amount of the 2nd part 22 is in the range of 20-500 mJ / cm < ² >, for example.

  Simultaneously with the exposure of the second coating film 2, the first coating film 1 is also exposed. The portions corresponding to the permeable portion 41 and the low permeable portion 42 in the first coating film 1 are irradiated with light, and this portion is cured. On the other hand, the portion corresponding to the non-permeable portion 43 in the first coating film 1 is not irradiated with light.

  After the exposure of the second coating film 2 and the first coating film 1, the second coating film 2 and the first coating film 1 are developed with an alkaline developer. Then, the third portion 23 of the second coating film 2 is removed from the printed wiring board 100, and the portion corresponding to the non-permeable portion 43 in the first coating film 1 is also removed from the printed wiring board 100. The The first portion 21 and the second portion 22 of the second coating film 2 remain on the printed wiring board 100.

After the exposure of the second coating film 2 and the first coating film 1, the second coating film 2 (the first portion 21 and the second portion 22) is heated. Heating temperature _{T h} of the second paint film 2 in this case, satisfy the relation T _h ≧ T _m -30, preferably satisfies the relation _{T m + 100 ≧ T h ≧} T m -30. In this formula, T _h (° C.) is the heating temperature of the second coating film 2, and T _m (° C.) is the melting point of the specific organic compound (J). The heating temperature is, for example, in the range of 100 to 200 ° C. The heating time is in the range of 20 minutes to 5 hours.

Thus was heated second coating at a heating temperature T _h, further in the range of 0.99 ° C. to 300 ° C., it may be heated under the condition in the range of 1 to 10 minutes. Furthermore, since the heated second coating at a heating temperature _{T h,} it may be irradiated with ultraviolet rays under the condition of the range of 100~5000mJ / cm ^2.

  When the second coating film 2 is heated in this way, bubbles are generated in the first portion 21. On the other hand, bubbles are not generated in the second portion 22 or bubbles are generated, but the ratio is lower than that of the first portion 21. Moreover, when the second resist composition contains an epoxy compound, when the second coating film 2 is heated in this way, a thermosetting reaction of the epoxy compound proceeds.

  After the first portion 21 and the second portion 22 are heated, the entire first portion 21 and the second portion 22 may be irradiated with light. In this case, the photopolymerization reaction of the photopolymerizable compound (G) remaining unreacted in the first portion 21 and the second portion 22 proceeds.

  As a result, as shown in FIG. 2C, a solder resist layer 10 made of a cured product of the first coating film 1 is formed on the printed wiring board 100, and the second coating film 2 is cured on the solder resist layer 10. A second resist layer 20 made of a material is formed. Thereby, a covering printed wiring board is obtained.

  The second resist layer 20 of the coated printed wiring board includes a first region 24 that is a cured product of the first portion 21 and a second region 25 that is a cured product of the second portion 22. The first region 24 contains bubbles. On the other hand, the second region 25 does not contain bubbles or contains bubbles at a lower density than the first region 24. For this reason, there is a difference in light transmittance between the first region 24 and the second region 25, and the second region 25 has a light transmittance higher than that of the first region 24.

  The ratio of bubbles contained in the first region 24 is preferably in the range of 3 to 70%, and more preferably in the range of 5 to 60%. Moreover, it is preferable that the ratio of the bubble contained in the 2nd area | region 25 with respect to the ratio of the bubble contained in the 1st area | region 24 exists in the range of 0-5%.

The ratio of the bubbles is 0.5 μm or more in the major axis on the surface appearing by polishing the surface of the second resist layer 20 (that is, the cross section of the second resist layer 20 along the surface of the second resist layer 20). The area ratio of bubbles. This area ratio is derived based on the area of bubbles having a major axis of 0.5 μm or more on the surface of the second resist layer 20 having a surface area of 20 μm ² , for example.

  The ratio of these bubbles can be controlled by appropriately adjusting the exposure amount for the first portion 21 and the exposure amount for the second portion 22.

  It is preferable that the thickness dimension of the 2nd resist layer 20 exists in the range of 10-40 micrometers, for example. In this case, the marking formed by the first region 24 and the second region 25 is further easily distinguished. When the thickness dimension of the second resist layer 20 is within this range, the ratio of bubbles in the first region 24 is preferably in the range of 5 to 70%, and the ratio of the ratio of bubbles in the second region 25 is Is preferably in the range of 0 to 5%.

In the second resist layer 20 formed on the solder resist layer 10, the L ^* value of the first region 24 is 35 or more, the a ^* value is -15 or less, and the b ^* value is in the range of -5 to 5. It is preferable that the L ^* value of the second region 25 is 32 or less, the a ^* value is in the range of −10 to 10 and the b ^* value is in the range of −5 to 5. In this case, the marking formed by the first region 24 and the second region 25 is particularly easy to distinguish.

L ^* value of the first region 24 of the second resist layer 20 on the solder resist layer 10 is 35 or more, a ^* value is −15 or less, b ^* value is in the range of −5 to 5, and In order for the L ^* value of the second region 25 to be 32 or less, the a ^* value to be in the range of −10 to 10 and the b ^* value to be in the range of −5 to 5, the colorant in the solder resist composition It is preferable that (E2) is a red colorant and the colorant (I) in the second resist composition is a green colorant. In this case, since the color of the colorant (E2) and the colorant (I) have a complementary relationship, it is easy to make the color of the second region 25 deep black. In particular, when only the solder resist layer 10 is provided on a copper plate, the L ^* value of the solder resist layer 10 is 40 or less, the a ^* value is in the range of 5.1 to 55, and the b ^* value is in the range of -15 to 15. It is preferable to be within. Further, when only the second resist layer 20 is provided on the copper plate, the L ^* value of the second region 25 in the second resist layer 20 is 35 or more, the a ^* value is in the range of −100 to −15, b ^* The value is preferably in the range of -20 to 20.

[Coated printed wiring board with solder resist layer]
The carboxyl group-containing unsaturated resin solutions used in Examples 1 to 5 and Comparative Examples 1 to 3 were prepared as follows.

  First, a cresol novolak type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., product number YDCN-700-5, epoxy equivalent 203) is placed in a four-necked flask equipped with a reflux condenser, a thermometer, an air blowing tube and a stirrer. A mixture was prepared by adding 203 parts by mass, 160.1 parts by mass of diethylene glycol monoethyl ether acetate, 0.2 parts by mass of methylhydroquinone, 72.7 parts by mass of acrylic acid, and 0.6 parts by mass of dimethylbenzylamine. This mixture was heated in a flask under the conditions of a heating temperature of 110 ° C. and a heating time of 10 hours, thereby causing the addition reaction to proceed.

  Subsequently, 60.8 parts by mass of tetrahydrophthalic anhydride and 78.9 parts by mass of diethylene glycol monoethyl ether acetate were added to the mixture in the flask and heated under the conditions of a heating temperature of 115 ° C. and a heating time of 3 hours. Thereby, a 65 mass% concentration solution of the carboxyl group-containing resin was obtained.

Details of raw materials other than the carboxyl group-containing unsaturated resin solutions used in Examples 1 to 5 and Comparative Examples 1 to 3 shown in Table 1 are as follows.
Epoxy resin: 1,3,5-triglycidyl isocyanurate (manufactured by Nissan Chemical Industries, TEPIC-HP).
Epoxy resin solution: A solution obtained by dissolving a cresol novolac type epoxy resin (manufactured by DIC Corporation, product name EPICLON N-695) in diethylene glycol monoethyl ether acetate at a solid content of 70%.
Photopolymerization initiator A: 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (manufactured by BASF, product name Irgacure 907).
Photopolymerization initiator B: 2,4-diethylthioxanthen-9-one (DETX).
Photopolymerization initiator C: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, product name Irgacure TPO manufactured by BASF.
Photopolymerization initiator D: 1-hydroxy-cyclohexyl-phenyl-ketone, product name Irgacure 184 manufactured by BASF.
Photopolymerizable monomer: dipentaerythritol hexaacrylate (DPHA).
Melamine: Fine melamine manufactured by Nissan Chemical Industries, Ltd.
Barium sulfate: Product name Variace B30 manufactured by Sakai Chemical Industry Co., Ltd.
・ Fine silica: Product name Leolosil MT-10 manufactured by Tokuyama Corporation.
Antifoaming agent: Product name KS-66 manufactured by Shin-Etsu Chemical Co., Ltd.
Perylene Black A: Product name Palogen Black S 0084 manufactured by BASF.
Perylene Black B: Product name Lumogen Black FK 4280 manufactured by BASF.
Carbon black: Product name MA7 manufactured by Mitsubishi Chemical Corporation.
Anthraquinone red pigment A: product name HOSTAPERSM SCARLET GO manufactured by Clariant Japan Ltd. (color index is Pigment Red 168).
Anthraquinone red pigment B: Product name Palogen Red L 4045 (Color Index Pigment Red 177) manufactured by BASF Corporation.
-Azo-based red pigment: Product name Seika First Red 1531B manufactured by Dainichi Seika Co., Ltd.
Solvent: diethylene glycol monoethyl ether acetate.
(Examples 1-5, Comparative Examples 1-3)
A solder resist composition was prepared by mixing these components at a ratio shown in Table 1.

  A wiring board provided with copper conductor wiring having a line width / line spacing of 0.2 mm / 0.3 mm and a thickness of 35 μm was prepared. A wet coating film was formed on the surface of the wiring board by applying the solder resist composition by screen printing. This wet coating film was pre-dried by heating at 80 ° C. for 20 minutes to form a dry coating film having a thickness of 20 μm.

The dried coating film is applied with a mask on which solder dams having a width of 25 μm, 50 μm, 75 μm, and 100 μm are formed and irradiated with ultraviolet rays under a condition of an irradiation energy density of 400 mJ / cm ² to dry the wiring substrate. The coating was selectively exposed.

  The dried coating film after the exposure was developed with an aqueous sodium carbonate solution to leave the portion cured by the exposure in the dried coating film on the wiring board, and the uncured portion was removed.

  Subsequently, the remaining dry coating film on the wiring board was cured by heating at 150 ° C. for 60 minutes. As a result, a solder resist layer including a solder dam having a thickness of 40 μm was formed on the wiring board.

(Color evaluation)
For the solder resist layers of Examples 1 to 5 and Comparative Examples 1 to 3, using a spectrocolorimeter (manufactured by Konica Minolta Sensing Co., Ltd., model number CM-600d), L in the L ^* a ^* b ^* color system ^{The *} value, a ^* value, and b ^* value were measured and judged as follows.
A: L ^* value is 40 or less, a ^* value is in the range of 5.1 to 55, and b ^* value is in the range of -15 to 15. B: L ^* value, a ^* value, and b ^* value When any one of the above is out of the range of “A” C: When two or more of the L ^* value, a ^* value, and b ^* value are out of the range of “A”.

(Peel test)
After attaching cellophane adhesive tape to the solder dams of Examples 1 to 5 and Comparative Examples 1 to 3, a peel test (tape test) was performed to peel the cellophane adhesive tape. As a result of the peeling test, the width of the narrowest solder dam among the remaining solder dams was measured and determined as follows.
A: The line width of the thinnest solder dam is 25 μm.
B: The narrowest solder dam has a line width of 50 μm.

  The results of these evaluations are shown in Table 1 below.

  According to Table 1, in Examples 1 to 5 where perylene black is used as a black pigment, the peel test is evaluated as “A”. On the other hand, in Comparative Example 3 in which carbon black is contained as a black pigment in the solder resist composition, the peel test is evaluated as “B”. This is considered to be because, in Examples 1 to 5, the solder resist layer is sufficiently cured to a deeper portion than Comparative Example 3.

According to Table 1, in Examples 1-5 in which a perylene-based black pigment and a pigment other than black are contained in the solder resist composition, the color evaluation is determined as “A”. On the other hand, in Comparative Example 1 in which only the perylene black is contained in the solder resist composition and no pigment other than black is contained, the color evaluation is determined as “B”, and the anthraquinone type is contained in the solder resist composition. In Comparative Example 2 that contains only a red pigment and no perylene black, the black color development in the low-exposure region is determined as “C”. This is because Comparative Example 1 does not contain a pigment other than black, and Comparative Example 2 does not contain a black pigment such as perylene black in the first place. Therefore, in the solder resist layers of Comparative Examples 1 and 2, the required L It is considered that the ^* value, a ^* value, and b ^* value could not be satisfied.

[About a coated printed wiring board provided with a solder resist layer and a second resist layer]
The carboxyl group-containing unsaturated resin solutions used in Examples 6 to 10 and Comparative Examples 4 to 6 were prepared as follows.

  First, a cresol novolak type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., product number YDCN-700-5, epoxy equivalent 203) is placed in a four-necked flask equipped with a reflux condenser, a thermometer, an air blowing tube and a stirrer. A mixture was prepared by adding 203 parts by mass, 103 parts by mass of diethylene glycol monoethyl ether acetate, 0.2 parts by mass of methylhydroquinone, 72 parts by mass of acrylic acid, and 1.5 parts by mass of triphenylphosphine. This mixture was heated under the conditions of a heating temperature of 110 ° C. and a heating time of 10 hours, thereby allowing the addition reaction to proceed. Subsequently, 60.8 parts by mass of tetrahydrophthalic anhydride and 78.9 parts by mass of diethylene glycol monoethyl ether acetate were added to the mixture, and the mixture was further heated under the conditions of a heating temperature of 80 ° C. and a heating time of 3 hours. Thereby, a 65 mass% concentration solution of the carboxyl group-containing unsaturated resin was obtained.

Details of the raw materials other than the carboxyl group-containing unsaturated resin solution used in Examples 6 to 10 and Comparative Examples 4 to 6 are as follows.
Photopolymerizable monomer: dipentaerythritol hexaacrylate (DPHA).
Crystalline epoxy compound: 1,3,5-triglycidyl isocyanurate (manufactured by Nissan Chemical Industries, TEPIC-HP).
Photopolymerization initiator A: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, product name Irgacure TPO manufactured by BASF.
Photopolymerization initiator B: 1-hydroxy-cyclohexyl-phenyl-ketone, product name Irgacure 184 manufactured by BASF.
Barium sulfate: Product name Variace B30 manufactured by Sakai Chemical Industry Co., Ltd.
・ Fine silica: Product name Leolosil MT-10 manufactured by Tokuyama Corporation.
Melamine: Fine melamine manufactured by Nissan Chemical Industries, Ltd.
Green colorant: phthalocyanine green.
Antifoaming agent: Product name KS-66 manufactured by Shin-Etsu Chemical Co., Ltd.
Solvent: diethylene glycol monoethyl ether acetate.
(Examples 6 to 10, Comparative Examples 4 to 6)
The second resist composition was prepared by mixing these components in the proportions shown in Table 2 below.

  A wiring board provided with copper conductor wiring having a line width / line spacing of 0.2 mm / 0.3 mm and a thickness of 35 μm was prepared. On the surface of this wiring board, the 1st coating film was formed by apply | coating the soldering resist composition used in Examples 1-5 and Comparative Examples 1-3 by the screen printing method. This first coating film was pre-dried by heating at 80 ° C. for 20 minutes, and the thickness was 20 μm.

  On this 1st coating film, the 2nd resist composition was apply | coated by the screen printing method, and the 2nd coating film was formed on the 1st coating film. This second coating film was pre-dried by heating at 80 ° C. for 20 minutes. The thickness of the second coating film after drying was 40 μm.

The second coating film is applied with a mask on which solder dams having a width of 25 μm, 50 μm, 75 μm, and 100 μm are formed, and the first coating film and the second coating film are irradiated with ultraviolet rays through the mask. Selective exposure. In this ultraviolet irradiation, a first portion and a second portion were set, and two types of ultraviolet rays having different irradiation energy densities were irradiated. The irradiation energy density of the ultraviolet rays irradiated to the first portion is 600 mJ / cm ² , and the irradiation energy density of the ultraviolet rays irradiated to the second portion is 70 mJ / cm ² .

  After the exposure, development treatment was performed with an aqueous sodium carbonate solution to leave the portions cured by the exposure in the first coating film and the second coating film on the wiring board, and the uncured portions were removed.

  Subsequently, the first coating film and the second coating film remaining on the wiring board were cured by heating at 150 ° C. for 60 minutes. Thereby, a solder resist layer and a second resist layer were formed. The total thickness of the solder resist layer and the second resist layer was 60 μm.

Of the formed second resist layer, the region corresponding to the second portion with the low irradiation energy density of the irradiated ultraviolet light is set as the low exposure region, and the first portion with the high irradiation energy density of the irradiated ultraviolet light is supported. The area to be used was the high exposure area.
(Peel test)
After the cellophane adhesive tape was affixed to the solder dams of Examples 6 to 10 and Comparative Examples 4 to 6, a peel test (tape test) was performed to peel the cellophane adhesive tape. As a result of this peeling test, the remaining solder dam having the narrowest line width (dam remaining) was measured and determined as follows.
A: The line width of the thinnest solder dam is 50 μm or more.
B: All the solder dams have been peeled off.

(About color evaluation in low exposure areas)
About the part corresponding to the low exposure area | region in the 2nd resist layer of Examples 6-10 and Comparative Examples 4-6, using a spectrocolorimeter (Konica Minolta Sensing Co., Ltd. make, model number CM-600d), L ^* a The L ^* value, a ^* value, and b ^* value in the ^* b ^* color system were measured and judged as follows.
A: When the L ^* value is 32 or less, the a ^* value is in the range of −10 to 10 and the b ^* value is in the range of −5 to 5.
B: ^{L *} value, ^{a *} value, and one of the ^{b *} value, when departing from the scope of the "A" C: ^{L *} value, ^{a *} value, and two or more of the ^{b *} values, When out of the range of “A”.

(About color evaluation in high exposure areas)
About the part corresponding to the high exposure area | region in the 2nd resist layer of Examples 6-10 and Comparative Examples 4-6, using a spectrocolorimeter (the Konica Minolta Sensing Co., Ltd. make, model number CM-600d), L ^* The L ^* value, a ^* value, and b ^* value in the a ^* b ^* color system were measured and judged as follows.
A: When the L ^* value is 35 or more, the a ^* value is −15 or less, and the b ^* value is in the range of −5 to 5.
B: ^{L *} value, ^{a *} value, and one of the ^{b *} value, when departing from the scope of the "A" C: ^{L *} value, ^{a *} value, and two or more of the ^{b *} values, When out of the range of “A”.

  The results of these evaluations are shown in Table 3 below.

  According to Table 3, in Examples 6 to 10 where perylene black is used as the black pigment, the peel test is evaluated as “A”. On the other hand, in Comparative Example 6 in which carbon black is included as a black pigment in the solder resist composition, the peel test is evaluated as “B”.

  This is considered to be because when the solder resist layer and the second resist layer are formed by one exposure, in Comparative Example 6, the solder resist layer cannot be sufficiently cured from the surface layer to the deep part.

  According to Table 3, in Examples 6 to 10 in which the solder resist composition contains a pigment other than perylene black and black, the black color development in the low exposure region and the green color development in the high exposure region were evaluated as “A”. Has been. On the other hand, in the comparative example 4 in which only the perylene black is contained in the solder resist composition and no pigment other than black is contained, the black color development in the low exposure region is evaluated as “B”. Further, in Comparative Example 5 in which only the anthraquinone red pigment is contained in the solder resist composition and no perylene black is contained, the black color development in the low exposure region is “C”, and the green color development in the high exposure region is “B”. It is evaluated.

This is because the appearance color of the second resist layer is green in the high-exposure area, and mixed color of green and the surface color of the solder resist layer in the low-exposure area. In Comparative Example 4, the solder resist composition is other than black. In Comparative Example 5, since the solder resist composition does not contain a black colorant, the first region having the required L ^* value, a ^* value, and b ^* value This is probably because the second resist layer including the second region could not be formed.

Claims (10)

Carboxyl group-containing resin (A),
One or more photopolymerizable compounds (B) selected from the group consisting of photopolymerizable monomers and photopolymerizable prepolymers,
Photopolymerization initiator (C),
Thermosetting component (D),
A perylene-based black colorant (E1) and a kind of colorant other than black (E2),
Containing
When a film having any thickness within a range of 18 to 22 μm is formed by photocuring on a copper plate and then thermosetting, the film has an L ^* value of 40 or less, and a ^* Solder resist composition whose value is in the range of 5.1-55 and whose b ^* value is in the range of -15-15. The solder resist composition according to claim 1, wherein the colorant (E2) is a red colorant. The solder resist composition according to claim 1, wherein the colorant (E2) is an anthraquinone red colorant. The solder resist composition according to any one of claims 1 to 3, wherein the thermosetting component (D) includes a compound having a cyclic ether skeleton. The solder resist composition according to any one of claims 1 to 4, wherein the carboxyl group-containing resin (A) includes a carboxyl group-containing resin (A2) having a photopolymerizable functional group. A printed wiring board;
A solder resist layer covering the printed wiring board;
With
A coated printed wiring board, wherein the solder resist layer is formed from the solder resist composition according to any one of claims 1 to 5. The coated printed wiring board according to claim 6, further comprising a second resist layer that covers the solder resist layer. The coated printed wiring board according to claim 7, wherein the second resist layer includes a first region and a second region having a light transmittance higher than that of the first region. The coated printed wiring board according to claim 7 or 8, wherein the second resist layer contains a green colorant. L ^* value of the first region is 35 or more, a ^* value is −15 or less, and b ^* value is in the range of −5 to 5,
10. The coated printed wiring board according to claim 8, wherein the L ^* value of the second region is 32 or less, the a ^* value is in the range of −10 to 10 and the b ^* value is in the range of −5 to 5. .

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