JP2002293815A - Photosensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin film whereby the adhesion to a base material and a conductor of a printed circuit is improved, the resistance to gold plating, acid resistance and moisture resistance are excellent and the thermal stability and a copper foil with little discoloration are obtained, especially the suitability as a solder resist for producing the circuit is given. SOLUTION: It is characterized by containing (A) an active energy ray- curable resin having at least two ethylenically unsaturated bonds in a molecule, (B) a compound in which a heterocyclic compound having a thiol group is potentialized by a protecting group, (C) a photopolymerization initiator and (D) a heat curing compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder for printed wiring boards, which has high adhesion to copper, has excellent gold plating resistance, acid resistance, and moisture resistance, and has low thermal stability and little discoloration of copper foil. The present invention relates to a photosensitive resin composition suitable as a resist.

[0002]

2. Description of the Related Art A printed wiring board is for mounting a pattern of a conductive circuit on a board by mounting an electronic component on a soldering land of the pattern by soldering. The remaining circuit portions are covered with a solder resist film as a permanent protective film. This prevents the solder from adhering to unnecessary parts when soldering electronic components to the printed wiring board, and also prevents the circuit conductors from being directly exposed to air and corroded by oxidation or humidity. . Conventionally, it has been the mainstream that a solder resist film is formed by patterning a solution composition on a substrate by a screen printing method, drying after removing a solvent, and then hardening by ultraviolet light or heat.

However, recently, with the demand for improvement (miniaturization) of the wiring density of a printed wiring board, a solder resist composition (also referred to as a solder resist ink composition) has been required to have high resolution and high precision. A liquid photo solder resist method (photo developing method) which is excellent in positional accuracy and covering property of a conductor edge portion has been proposed from a screen printing method regardless of a substrate for use or a substrate for industrial use. For example, JP-A-50-
No. 144431 and JP-A-51-40451,
A solder resist composition comprising a bisphenol type epoxy acrylate, a sensitizer, an epoxy compound, an epoxy curing agent and the like is disclosed. These solder resist compositions are applied to the entire surface of the liquid composition, which is a photosensitive resin composition, on a printed wiring board, and after evaporating the solvent, the exposed and unexposed portions are removed using an organic solvent. To be developed. However, the removal (development) of the unexposed portion with the organic solvent involves the use of a large amount of the organic solvent, so that not only there is a risk of environmental pollution and fire, but also there is a problem of environmental pollution, and particularly, it is given to the human body. At present, it is difficult to take countermeasures, as the impact has been greatly increased recently.

In order to solve these problems, an alkali developing type photo solder resist composition which can be developed with a dilute aqueous alkali solution has been proposed. For example, JP-A-56-4
No. 0329 and JP-A-57-45785 disclose a material in which a reaction product obtained by reacting an unsaturated monocarboxylic acid with an epoxy resin and further adding a polybasic acid anhydride is used as a base polymer. . In addition, 1-5439
Japanese Patent Publication No. JP-A No. 0-204, discloses an active energy ray-curable resin obtained by reacting a reaction product of a novolak type epoxy resin with an unsaturated monocarboxylic acid, and a saturated or unsaturated polybasic acid anhydride, and a photopolymerization initiator. A photocurable liquid resist ink composition that can be developed with a dilute aqueous alkali solution containing is disclosed.

[0005] These liquid solder resist compositions include:
By introducing a carboxyl group into the epoxy acrylate, photosensitivity and developability in a dilute alkaline aqueous solution are imparted, but the composition is further exposed to light and developed to give the desired composition. After the formation of the resist pattern, usually, for thermosetting, generally contains an epoxy resin as a thermosetting component, and reacts the carboxyl group of the side chain introduced into the above epoxy acrylate with the epoxy group to form an adhesive. A resist film having excellent hardness, heat resistance, chemical resistance, electrical insulation and the like is formed. In this case, a curing agent for epoxy resin is generally used together with the epoxy resin.

[0006]

Basically, an epoxy compound is known as a material having a high adhesiveness. However, when used as a thermosetting component of a solder resist, other photosensitive resins and reactive compounds are used. It is used in combination with a diluent or the like, and after photo-curing, it is heat-cured and used, so that it cannot be said that the adhesiveness to the circuit portion made of the substrate or the conductor of the printed wiring board is sufficient. In order to improve this adhesiveness, for example, Japanese Patent No. 2792298 discloses a photo solder resist composition containing a triazine thiol compound together with, for example, a carboxyl group-introduced epoxy acrylate of a photopolymerizable resin, a photopolymerization initiator and an epoxy compound. When this is used for a printed wiring board, the action of the triazine thiol compound to form a chelate with a metal and the action of reacting with the carboxyl group-introduced epoxy acrylate of the photopolymerizable resin and the unsaturated double bond of the unsaturated compound Accordingly, there is a description that the adhesion between the metal and the photo solder resist film can be remarkably improved. Therefore, gold plating resistance, acid resistance, moisture resistance, and the like can be significantly improved. However, a compound having a thiol group (—SH) such as a triazine thiol compound reacts with an unsaturated double bond such as a photopolymerizable resin,
This degrades the thermal stability of the solder resist, causing a reduction in the thermal sensitivity range and poor development (remaining development).
Further, since a complex is formed on the developed portion of the copper foil and remains as attached, there is a problem that not only discoloration of the copper foil occurs but also soldering failure occurs at the time of subsequent component mounting.

An object of the present invention is to solve the above-mentioned problems, and has high adhesion to copper, gold plating resistance, acid resistance,
It is an object of the present invention to provide a photosensitive resin composition which has excellent moisture resistance, further has low thermal stability and little discoloration of a copper foil, and is suitable as, for example, a solder resist for a printed wiring board.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, by modifying the thiol group of triazine thiols, the reactivity was reduced, and the thermal stability was reduced. By maintaining and further preventing the formation of the complex, adhesion to the copper foil can be prevented, and the adhesion to the substrate and conductor of the printed wiring board is improved, and the gold plating resistance, acid resistance, and moisture resistance are excellent. Further, the inventors have found that a photosensitive resin film having low thermal stability and little discoloration of a copper foil and particularly suitable as a solder resist for producing a printed wiring board is provided, and the present invention has been accomplished. That is, the present invention
(1) (A) an active energy ray-curable resin having at least two ethylenically unsaturated bonds in one molecule, (B)
A photosensitive resin composition comprising: a compound obtained by making a heterocyclic compound having a thiol group latent by a protecting group; (C) a photopolymerization initiator; and (D) a thermosetting compound.
(2) The photosensitive resin composition according to the above (1), wherein the compound in which a heterocyclic compound having a thiol group is latentized by a protecting group is a triazine thiol represented by the following chemical formula (1). ,

Embedded image (Wherein R represents an alkyl group having 1 to 10 carbon atoms, or an aromatic group, or an alkoxyl group, an amino group, or a thiol group). (3) A heterocyclic compound having a thiol group is 2,5. -A thiazole represented by dimercapto-1,3,4-thiadiazole; (1) a photosensitive resin composition according to (2), (4) having two or more thiol groups; Wherein the protecting group used in obtaining the compound obtained by latentifying the compound with a protecting group is a vinyl ether compound, wherein the photosensitive resin composition according to any one of the above (1) to (3), Group 2
The photosensitive resin composition according to any one of (1) to (4), wherein the protecting group used in obtaining the compound obtained by latentifying the compound having two or more compounds with a protecting group is an isocyanate compound. provide.

In the present invention, “(A) an active energy ray-curable resin having at least two ethylenically unsaturated bonds in one molecule” includes, for example, a polyfunctional epoxy having two or more epoxy groups in a molecule. After reacting a radically polymerizable unsaturated monocarboxylic acid such as acrylic acid or methacrylic acid with at least a part of the epoxy group of the resin, there may be mentioned those obtained by reacting a polybasic anhydride with a generated hydroxyl group. .

As the polyfunctional epoxy resin, any epoxy resin having two or more functionalities can be used, and there is no particular limitation on the epoxy equivalent.
Hereinafter, those having 100 to 500 are preferably used. For example, bisphenol type epoxy resins such as bisphenol A type, bisphenol F type, bisphenol AD type, o-
Novolak type epoxy resin such as cresol novolak type, bisphenol A novolak type epoxy resin, cycloaliphatic polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, glycidylamine type polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol Modified novolak type epoxy resins, polyfunctional modified novolak type epoxy resins, condensate type epoxy resins of phenols and aromatic aldehydes having a phenolic hydroxyl group, and the like can be given. Further, resins obtained by introducing halogen atoms such as Br and Cl into these resins may also be used. Of these, novolak type epoxy resins are preferable in consideration of heat resistance. These epoxy resins may be used alone or in combination of two or more.

These epoxy resins are reacted with a radically polymerizable unsaturated monocarboxylic acid. The epoxy group is cleaved by the reaction between the epoxy group and the carboxyl group to form a hydroxyl group and an ester bond. The radically polymerizable unsaturated monocarboxylic acid to be used is not particularly limited and includes, for example, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, etc., and at least one of acrylic acid and methacrylic acid (hereinafter, (meth) acrylic acid). Acid). Acrylic acid is particularly preferred. There is no particular limitation on the reaction method between the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid. For example, the reaction can be performed by heating the epoxy resin and acrylic acid in a suitable diluent. Examples of the diluent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol, isopropanol and cyclohexanol; and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane. Petroleum solvents such as petroleum ether, petroleum naphtha, cellosolves such as cellosolve and butyl cellosolve, carbitols such as carbitol and butyl carbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate and butyl Acetates such as carbitol acetate can be exemplified. Examples of the catalyst include amines such as triethylamine and tributylamine, and phosphorus compounds such as triphenylphosphine and triphenylphosphate.

In the reaction between the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid, it is possible to react 0.7 to 1.2 equivalents of the radically polymerizable unsaturated monocarboxylic acid per equivalent of the epoxy group of the epoxy resin. preferable. When at least one of acrylic acid and methacrylic acid is used, the reaction is more preferably performed by adding 0.8 to 1.0 equivalent. When the amount of the radically polymerizable unsaturated monocarboxylic acid is less than 0.7 equivalent, gelation may occur at the time of the synthesis reaction in the subsequent step, or the stability of the resin is reduced. If the amount of the radically polymerizable unsaturated monocarboxylic acid is excessive, a large amount of unreacted carboxylic acid remains, which may lower various properties (for example, water resistance) of the cured product. The reaction between the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid is preferably performed in a heated state, and the reaction temperature is preferably 80 to 140 ° C. When the reaction temperature is higher than 140 ° C., the radical polymerizable unsaturated monocarboxylic acid is liable to cause thermal polymerization and the synthesis may be difficult. When the reaction temperature is lower than 80 ° C., the reaction rate is slow, which is not preferable in actual production. There is. In the reaction of the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid in a diluent, the amount of the diluent is preferably 20 to 50% based on the total weight of the reaction system. The reaction product of the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid can be subjected to the next reaction with a polybasic acid without isolation as a solution of a diluent.

A polybasic acid or an anhydride thereof is reacted with an unsaturated monocarboxylic oxidized epoxy resin which is a reaction product of the above epoxy resin and a radical polymerizable unsaturated monocarboxylic acid. The polybasic acid or its anhydride is not particularly limited, and any of saturated and unsaturated acids can be used. Such polybasic acids include succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid,
Methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid, hexahydrophthalic acid, 3-
Methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendmethylene Examples thereof include tetrahydrophthalic acid, trimellitic acid, pyromellitic acid, and diglycolic acid, and the polybasic acid anhydride includes these anhydrides. These compounds can be used alone or in combination of two or more. The polybasic acid or polybasic acid anhydride reacts with a hydroxyl group generated by the reaction between the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid to give the resin a free carboxyl group.
The amount of the polybasic acid to be reacted is desirably 0.3 to 1.0 mol per 1 mol of the hydroxyl group of the reaction product of the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid. From the viewpoint that a highly sensitive resin film can be obtained at the time of exposure, the reaction is preferably performed in a ratio of 0.4 to 1.0 mol, more preferably 0.6 to 1.0 mol. If the amount is less than 0.3 mol, the diluted alkali developability of the obtained resin may decrease. If the amount exceeds 1.0 mol, various properties (for example, water resistance) of the finally obtained cured coating film may be reduced. May lower. The polybasic acid is added to the unsaturated monocarboxylic oxide epoxy resin, is subjected to a dehydration condensation reaction, and water generated during the reaction is preferably continuously removed from the reaction system, but the reaction is preferably performed in a heated state. Preferably, the reaction temperature is 70-130 ° C. When the reaction temperature is higher than 130 ° C., the compound bonded to the epoxy resin and the radically polymerizable unsaturated group of the unreacted monomer are liable to cause thermal polymerization, making the synthesis difficult. The speed is reduced, which may not be preferable in actual production. The acid value of the polybasic acid-modified unsaturated monocarboxylic epoxy resin, which is a reaction product of the above polybasic acid and the unsaturated monocarboxylic epoxy resin, is 60
~ 300 mgKOH / g is preferred. The acid value of the reaction product can be adjusted by the amount of the polybasic acid to be reacted.

In the present invention, the above polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin can also be used as the photosensitive resin. It is also preferable that a glycidyl compound having one or more radically polymerizable unsaturated groups and an epoxy group is reacted to further introduce a radically polymerizable unsaturated group, thereby obtaining a photosensitive resin having further improved photosensitivity. In the photosensitive resin with improved photosensitivity, the radical polymerizable unsaturated group is bonded to the side chain of the polymer skeleton of the precursor photosensitive resin by the reaction of the last glycidyl compound, so that the photopolymerization reaction is performed. Nature,
It can have excellent photosensitive characteristics. Compounds having one or more radically polymerizable unsaturated groups and epoxy groups include:
For example, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, pentaerythritol triacrylate monoglycidyl ether and the like can be mentioned. Note that a plurality of glycidyl groups may be present in one molecule. These compounds may be used alone or as a mixture. The glycidyl compound is added to the solution of the above polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin and allowed to react, and usually 0.05 to 0.5 mol per 1 mol of carboxyl groups introduced into the resin. React in proportions. In consideration of the photosensitivity (sensitivity) of the photosensitive resin composition containing the obtained photosensitive resin, and the above-described electrical characteristics such as the heat management width and the electrical insulation, preferably 0.1 to 0.5. It is advantageous to react in molar proportions. The reaction temperature is preferably from 80 to 120C. The photosensitive resin comprising the glycidyl compound-added polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin thus obtained preferably has an acid value of 45 to 250 mgKOH / g.

In the present invention, “(B) a compound obtained by rendering a heterocyclic compound having a thiol group latent by a protecting group”
Is typically a triazine thiol represented by the following [Chemical Formula 1].

Embedded image (Wherein R represents an alkyl group having 1 to 10 carbon atoms, or an aromatic group, or an alkoxyl group, an amino group, or a thiol group) Specifically, 2,4,6-trithiol-1, 3,5-triazine, 2-dimethylamino-4,
6-dithiol-1,3,5-triazine, 2-dibutylamino-4,6-dithiol-1,3,5-triazine, 2-phenylamino-4,6-dithiol-1,
3,5-triazine and the like. Alternatively, thiazoles represented by 2,5-dimercapto-1,3,4-thiadiazole. Examples of the protective group used for obtaining a compound in which a compound having two or more thiol groups is latentized by a protective group include vinyl ether compounds and isocyanate compounds. Examples of the vinyl ether compounds include ethyl vinyl ether, butyl vinyl ether, 2,3-dihydrofuran, and 2,3-dihydropyran. As isocyanate compounds, phenyl isocyanate, ethyl isocyanate,
Butyl isocyanate and toluene diisocyanate. A triazine thiol represented by the following formula:
To obtain a compound in which a compound having two or more thiol groups, such as thiazoles, is latentified by a protecting group, a vinyl ether or an isocyanate is used for one equivalent of the thiol group of the compound having two or more thiol groups. Is 1 to
React 1.5 equivalents. The reaction temperature is preferably from room temperature to 60 ° C. Compounds in which a heterocyclic compound having a thiol group is latentized by a protecting group include 2,4,6-
Tris- (1-ethoxyethylsulfanyl) -1,
3,5-triazine, 2,4,6-tris- (1-butoxyethylsulfanyl) -1,3,5-triazine,
2,4,6-tris- (tetrahydrofuran-2-ylsulfanyl) -1,3,5-triazine, 2,4,6
-Tris- (phenylthiocarbamiolsulfanyl)
Examples thereof include -1,3,5-triazine and the like. The amount of the heterocyclic compound having a thiol group latentified by a protecting group is usually 0.1 to 100 g per 100 g of the photosensitive resin.
5 g. If the amount is less than 0.1 g, it is difficult to improve the adhesion of the cured coating film, and it is not possible to expect the improvement in gold plating resistance, acid resistance, and moisture resistance. On the other hand, if it exceeds 5 g, not only the thermal stability decreases, but also the properties of the cured coating film deteriorate due to the influence of unreacted substances. From the viewpoints of photocurability, economy, and mechanical properties of the cured coating film, the amount used is preferably 1 to 3 g.

In the present invention, "(C) photopolymerization initiator"
There is no particular limitation, and any conventionally known one can be used. Specifically, typical examples include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, and 2,2-dimethoxy-2. -Phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (methylthio ) Phenyl] -2-morpholino-propan-1-one, 4
-(2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, -Tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenonedimethylketal, P- And dimethylaminobenzoic acid ethyl ester. These can be used alone or in combination. The amount of the photopolymerization initiator used depends on the amount of the photosensitive resin 1
It is usually 0.5 to 50 g with respect to 00 g. 0.5g
If it is less, the photocuring reaction of the photosensitive resin does not easily proceed,
If it exceeds 50 g, the effect is not improved for the added amount, but it may be disadvantageous economically or the mechanical properties of the cured coating film may be deteriorated. From the viewpoints of photocurability, economy, and mechanical properties of the cured coating film, the amount used is preferably 2.0 to 30 g.

In the present invention, as the “(D) thermosetting compound”, for example, a curing agent for epoxy resin and / or a curing accelerator can be used. As the curing agent, dicyandiamide organic acid salt and its derivative N-
At least one kind of organic acid salts of substituted dicyandiamides is included. Examples of the substituent of the N-substituted dicyandiamide include a linear or branched alkyl group having 1 to 12 carbon atoms, an aryl group which may have a nuclear substituent such as an alkyl group, aralkyl, and the like. Examples thereof include organic carboxylic acids, organic phosphoric acids, and organic sulfuric acids. These compounds may be used in combination of at least two kinds (two or more kinds), and the content thereof is generally selected in the range of 0.1 to 10 g per 100 g of the component (A).
If the content is less than 0.1 g, the thermosetting properties may not be sufficiently exhibited. If the content exceeds 10 g, the pot life of the photosensitive resin composition of the present invention is likely to be short, and the solder resist film of the coating film is easily formed. It may cause deterioration of characteristics. In consideration of the thermosetting properties, the pot life of the composition, the properties of the solder resist film, and the like, the content of the compound as a curing agent is particularly preferably in the range of 1 to 8 g. The details are described in the specification of Japanese Patent Application No. 2000-277430, and points other than the above can be applied. As the curing agent, N-substituted dicyandiamide and dicyandiamide having the above substituents can also be used, and at least two of these may be used in combination, including the above compounds. Known epoxy curing accelerators such as melamine compounds, imidazole compounds, phenol compounds and the like can be used as the curing accelerator. These promote post-curing of the component (B) and the like.

The photosensitive resin composition of the present invention comprises the above (A)
By mixing and using a reactive diluent in addition to the component, the component (B), the component (C) and the component (D), it is possible to suitably use the composition as a solder resist composition for producing a printed wiring board, for example. it can.

The reactive diluent is used to further enhance the photo-curing of the photosensitive resin to obtain a coating film having acid resistance, heat resistance, alkali resistance and the like.
A compound having at least two double bonds in one molecule is preferably used. Typical examples of the reactive diluent include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and polyethylene glycol. Di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, neopentyl glycol di (meth) acrylate hydroxypivalate, dicyclopentanyl di (meth) acrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, ethylene Oxide-modified phosphate di (meth) acrylate, allylated cyclohexyldi (meth) acrylate, isocyanurate di (meth)
Acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid-modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) Reactive diluents such as acrylate, tris (acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and caprolactone-modified dipentaerythritol hexa (meth) acrylate Can be

The above difunctional difunctional or hexafunctional diluents can be used either individually or in a mixture of a plurality of diluents. The addition amount of the reactive diluent is
It is usually 2.0 to 40 g with respect to 00 g. If the added amount is less than 2.0 g, sufficient photocuring cannot be obtained, and the cured coating film cannot have sufficient properties in terms of acid resistance, heat resistance, and the like, and if the added amount exceeds 40 g, the tack becomes severe. ,
At the time of exposure, the artwork film easily adheres to the substrate, and it becomes difficult to obtain a desired cured coating film. The amount of the reactive diluent to be added is preferably 4.0 to 20 g from the viewpoint of preventing the artwork film from adhering to the substrate, such as photocurability, acid resistance and heat resistance of the cured coating film.

In the photosensitive resin composition of the present invention, in addition to the above-mentioned components, if necessary, various additives such as a filler comprising an inorganic pigment such as silica, alumina, talc, calcium carbonate, barium sulfate, etc. And known color pigments such as phthalocyanine-based and azo-based organic pigments such as phthalocyanine green and phthalocyanine blue, and inorganic pigments such as titanium dioxide, and coating additives such as an antifoaming agent and a leveling agent.

The photosensitive resin composition of the present invention obtained as described above is applied in a desired thickness to a printed wiring board having a circuit pattern formed by etching a copper foil of a copper-clad laminate, for example. And at a temperature of about 60 to 80 ° C for 15 to
After heating for about 60 minutes to evaporate the solvent, a negative film of a light-transmissive pattern is adhered to the circuit pattern except for the soldering land of the circuit pattern, and ultraviolet light is irradiated on the negative film. The coating film is developed by removing the non-exposed area corresponding to the above with a diluted alkaline aqueous solution. The diluted alkaline aqueous solution used at this time is 0.5
A ~ 5% aqueous sodium carbonate solution is common, but other alkalis can be used. Then, when the composition contains a thermosetting compound, the desired solder resist film can be formed by performing post-curing for 20 to 80 minutes using a hot-air circulation type dryer at 130 to 170 ° C. In this way, a printed wiring board coated with a solder resist film is obtained, and electronic components are connected, fixed, and mounted by being soldered by a jet soldering method or a reflow soldering method. A circuit unit is formed. In the present invention, both the printed wiring board coated with the solder resist film before mounting the electronic component and the printed wiring board after mounting the electronic component on the printed wiring board are included in the scope of the present invention.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

[0024]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. (Synthesis example of a compound in which a heterocyclic compound having a thiol group as the component (B) is latentized by a protecting group)

Synthesis Example 1 2, 4 and 6 were placed in a 2 L flask equipped with a reflux tube and a stirrer.
-Charge 177 g of trithiol-1,3,5-triazine, 400 g of ethyl vinyl ether and 1000 mL of acetone. The mixture was heated and refluxed for 12 hours while stirring, and then acetone and excess ethyl vinyl ether were removed by distillation under reduced pressure, and 350 g of 2,4,6-tris- (1-ethoxyethylsulfanyl) -1,3,5-triazine was removed.
I got

Synthesis Example 2 2, 4 and 6 were placed in a 2 L flask equipped with a reflux tube and a stirrer.
-Charge 177 g of trithiol-1,3,5-triazine, 450 g of butyl vinyl ether and 1000 mL of acetone. The mixture was heated and refluxed for 12 hours while stirring, and then acetone and excess butyl vinyl ether were removed by distillation under reduced pressure, and 430 g of 2,4,6-tris- (1-butoxyethylsulfanyl) -1,3,5-triazine was removed.
I got

Synthesis Example 3 2, 4 and 6 were placed in a 2 L flask equipped with a reflux tube and a stirrer.
-177 g of trithiol-1,3,5-triazine, 400 g of 2,3-dihydrofuran and 1000 m of acetone
Input L. Heat and reflux for 12 hours while stirring,
Thereafter, acetone and excess 2,3-dihydrofuran were removed by distillation under reduced pressure to obtain 360 g of 2,4,6-tris- (tetrahydrofuran-2-ylsulfanyl) -1,3,5-triazine.

Synthesis Example 4 2, 4 and 6 were placed in a 2 L flask equipped with a reflux tube and a stirrer.
-177 g of trithiol-1,3,5-triazine, 380 g of phenylisocyanate and 1000 mL of acetone
Input. The mixture was heated under reflux with stirring for 12 hours, and then acetone and excess phenylisocyanate were removed by distillation under reduced pressure to give 2,4,6-tris- (phenylthiocarbamiolsulfanyl) -1,3,5-triazine. 480 g were obtained.

Method for Producing Photosensitive Resin (A) In 206 g of ethyl carbitol acetate, acrylic acid is reacted at a ratio of 1 mol with respect to 1 mol of epoxy group of a cresol novolak type epoxy resin having an epoxy equivalent of 220. The reaction product was reacted with tetrahydrophthalic anhydride at a ratio of 0.6 mol to produce a photosensitive resin. This was a viscous liquid with an acid value of 57 mgKOH / g.

Example 1 To 100 g of the photosensitive resin (A) obtained in the resin production example, 2,4,6-tris- (1-ethoxyethylsulfanyl) -1,3,5-triazine obtained in synthesis example 1 was added. 2 g, dipentaerythritol hexaacrylate 8 g, 2-methyl-
1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one 5 g, 2,4-diethylthioxanthone 1 g, silica 10 g, barium sulfate 13 g, triglycidyl isocyanurate 10 g, phthalocyanine green 1 g 3 rolls To prepare a photosensitive resin composition. Table 1 shows the evaluation results of the developability and coating film performance of this composition.

Example 2 100 g of the photosensitive resin (A) obtained in Resin Production Example was added to 2,4,6-tris- (1-butoxyethylsulfanyl) -1,3,5-triazine obtained in Synthesis Example 2. 2 g, dipentaerythritol hexaacrylate 8 g, 2-methyl-
1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one 5 g, 2,4-diethylthioxanthone 1 g, silica 10 g, barium sulfate 13 g, triglycidyl isocyanurate 10 g, phthalocyanine green 1 g 3 rolls To prepare a photosensitive resin composition. Table 1 shows the evaluation results of the developability and coating film performance of this composition.

Example 3 100 g of the photosensitive resin (A) obtained in the resin production example was added to the 2,4,6-tris- (tetrahydrofuran-
2-ylsulfanyl) -1,3,5-triazine2
g, dipentaerythritol hexaacrylate 8 g,
2-methyl-1- [4- (methylthio) phenyl] -2
5 g of morpholino-propan-1-one, 1 g of 2,4-diethylthioxanthone, 10 g of silica, 13 g of barium sulfate, 10 g of triglycidyl isocyanurate, and 1 g of phthalocyanine green were mixed and dispersed with three rolls to prepare a photosensitive resin composition. Prepared. Table 1 shows the evaluation results of the developability and coating film performance of this composition.

Example 4 100 g of the photosensitive resin (A) obtained in Resin Production Example was added to 2,4,6-tris- (phenylthiocarbamiolsulfanyl) -1,3,5- obtained in Synthesis Example 4. Triazine 2 g, dipentaerythritol hexaacrylate 8 g, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one 5 g, 2,4-diethylthioxanthone 1 g, silica 10 g, barium sulfate 13
g, triglycidyl isocyanurate 10 g, and phthalocyanine green 1 g were mixed and dispersed with a three-roll mill to prepare a photosensitive resin composition. Table 1 shows the evaluation results of the developability and coating film performance of this composition.

Comparative Example 1 To 100 g of the photosensitive resin (A) obtained in the resin production example, 2
4,6-trithiol-1,3,5-triazine 1 g,
8 g of dipentaerythritol hexaacrylate, 2-
Methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one 5 g, 2,4-diethylthioxanthone 1 g, silica 10 g, barium sulfate 1
3 g, triglycidyl isocyanurate 10 g, and phthalocyanine green 1 g were mixed and dispersed with three rolls,
A photosensitive resin composition was prepared. Table 1 shows the evaluation results of the developability and coating film performance of this composition.

Comparative Example 2 8 g of dipentaerythritol hexaacrylate, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane-1 were added to 100 g of the photosensitive resin (A) obtained in the resin production example. -One 5 g, 2,4-diethylthioxanthone 1 g, silica 10 g, barium sulfate 13 g,
10 g of triglycidyl isocyanurate and 1 g of phthalocyanine green were mixed and dispersed with a three-roll mill to prepare a photosensitive resin composition. Table 1 shows the evaluation results of the developability and coating film performance of this composition.

Evaluation Test Method (1) Thermal Management Width A substrate obtained by extending the predrying time at intervals of 10 minutes was used as an evaluation substrate, and a 1% aqueous sodium carbonate solution was used at 2.0 kg / c.
Developing was performed at a spray pressure of m ² for 60 seconds to evaluate how many minutes the predrying time could be completely removed. (2) Performance of coating film The photosensitive resin composition was applied on the entire surface of the copper foil substrate on which the pattern was formed, and dried at 80 ° C for 20 minutes. Next, a negative film was brought into close contact with the substrate, and after exposure, developed with a 1% by weight aqueous solution of sodium carbonate to form a pattern. Next, the substrate was thermally cured at 150 ° C. for 60 minutes to prepare an evaluation substrate having a cured coating film, and the coating film performance was evaluated. (A) Gold plating resistance Gold plating was performed on an evaluation substrate having a cured coating film, and a peeling test was performed with a cellophane adhesive tape. Peeling of the resist layer and discoloration were observed, and gold plating property was evaluated. ◎: No change was observed, 全 く: Slight change Δ: Notable change, ×: Coating swelled and peeled (b) Adhesion JIS D-0202 In accordance with this, it was measured by a grid test. (C) Pencil hardness Measured according to JIS K-5400.6.14. (D) Acid resistance The evaluation substrate having the cured coating film was immersed in a 10% by weight sulfuric acid aqueous solution at room temperature for 30 minutes, washed with water, and subjected to a peeling test with a cellophane adhesive tape to observe the peeling and discoloration of the resist layer. The acid resistance was evaluated. ◎: No change was observed, ：: Slight change Δ: Notable change, X: Coating swelled and peeled (e) Solvent resistance Evaluate the substrate with methylene chloride at room temperature for 30 minutes.
After immersion for a minute, after washing with water, a peeling test was carried out using a cellophane adhesive tape, and peeling and discoloration of the resist layer were observed to evaluate solvent resistance. ◎: No change was observed at all, ○: Slight change was observed △: Notable change was observed, ×: Film was swollen and peeled (f) Heat resistance Having cured film According to the test method of JIS C 6481, the evaluation board was immersed in a solder bath at 260 ° C. for 30 seconds, and the peeling test using cellophane tape was defined as one cycle, and the state of the coating film after performing a total of 1 to 3 cycles was observed. The heat resistance was evaluated. ◎: no change in coating film after 3 cycles, ○: slight change after 3 cycles, Δ: change after 2 cycles, x: peeling after 1 cycle ( G) Electrical characteristics Using an IPC SM-840B B-25 comb-shaped electrode B coubon, an evaluation substrate was prepared under the above conditions,
A DC voltage of 100 V was applied in a constant temperature and humidity chamber of 90% RH, the insulation resistance after 500 hours was measured, and the discoloration was observed to evaluate the electrical characteristics. ◎: No discoloration at all, ：: Thinly discolored Δ: Notable discoloration, ×: Black and scorched (H) Discoloration of copper foil Heat curing at 150 ° C. for 60 minutes was completed. Check the degree of discoloration of the copper foil on the board. ：: No discoloration at all, ○: Thinly discolored Δ: Notable discoloration, ×: Discolored up to the part protected by the resist

[0037]

[Table 1]

As can be seen from Table 1, the system using thiols latentized by using a protecting group has excellent thermal stability,
There is no discoloration of the copper foil, and the properties of the cured coating film are comparable to those using a thiol compound. The present invention improves the adhesion of the printed wiring board to the base material and the conductor, and is excellent in gold plating resistance, acid resistance, and moisture resistance.
It is clear that there is an effect that the heat stability and the discoloration of the copper foil are small.

[0039]

According to the present invention, the adhesion of the printed wiring board to the base material and the conductor is improved, the gold plating resistance, the acid resistance, and the moisture resistance are excellent, and the thermal stability and the discoloration of the copper foil are improved. And a photosensitive resin composition having a small amount of the resin can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/085 G03F 7/085 F-term (Reference) 2H025 AA02 AA04 AA07 AA11 AA14 AB15 AC01 AD01 BC13 BC74 BC85 BC86 CC06 CC17 CC20 4J011 PA43 PA45 PB24 PB40 QA03 QA37 QB20 QB22 SA02 SA05 SA06 SA15 SA16 SA22 SA23 SA25 SA27 SA28 SA29 SA32 SA34 SA54 SA63 SA64 TA03 TA04 TA08 TA10 UA00 UA01 UA06 WA01 WA02 4J027 AC03 BA21 BA03 BA21 BA03 BA03 CA25 CA26 CB10 CC04 CC05 CD10

Claims (5)

[Claims] (A) an active energy ray-curable resin having at least two ethylenically unsaturated bonds in one molecule, (B) a compound in which a heterocyclic compound having a thiol group is latentized by a protecting group, A photosensitive resin composition comprising (C) a photopolymerization initiator and (D) a thermosetting compound. 2. A compound in which a heterocyclic compound having a thiol group is latentized by a protecting group is a triazine thiol represented by the following chemical formula (1).
The photosensitive resin composition as described in the above. Embedded image (Wherein R represents an alkyl group having 1 to 10 carbon atoms, or an aromatic group, or an alkoxyl group, an amino group, or a thiol group) 3. The heterocyclic compound having a thiol group is 2,2.
3. Thiazoles represented by 5-dimercapto-1,3,4-thiadiazole.
The photosensitive resin composition according to claim 2. 4. The protecting group according to claim 1, wherein the protecting group used for obtaining a compound in which a compound having two or more thiol groups is latentized by the protecting group is a vinyl ether compound. Photosensitive resin composition. 5. The protecting group according to claim 1, wherein the protecting group used in obtaining a compound in which a compound having two or more thiol groups is latentized by the protecting group is an isocyanate compound. Photosensitive resin composition.