JP2002099081A - Photosensitive resin composition and printed-wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition which is capable of being developed by exposing to ultraviolet rays and being developed by a dilute aqueous alkaline solution and is excellent in finger touch dryability when a coated film is dried and which has a wide range of heat control and high sensibility and is excellent in colose adhesion, heat-resistance, chemical resistance or the like and is suitable for a soldering resist film for a printed-wiring board, and also provide a printed-wiring board having a cured coated film using the same. SOLUTION: The photosensitive resin composition containing (A) an active energy beam-curable resin having at least two ethylenically unsaturated bonds in one molecule, (B) a compound having at least two allyl groups, (C) a photopolymerization initiator, (D) a reactive diluent and (E) an epoxy-based thermosetting curable compound. For the printed-wiring board, this composition is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is capable of forming an image by exposure to ultraviolet light and development with a dilute aqueous alkaline solution. For example, the dryness of a coating film when the exposure film is brought into contact, that is, the so-called touch dryness is excellent. In addition, the photosensitive resin composition has good sensitivity, has a wide range of heat management, and can provide a coating film excellent in adhesion, heat resistance, chemical resistance and the like. The present invention relates to a printed wiring board using the same.

[0002]

2. Description of the Related Art A printed wiring board is used for mounting a conductive circuit pattern on a substrate by forming a pattern of the conductive circuit on the substrate and soldering the electronic component to a soldering land of the pattern. The remaining circuit portions are covered with a solder resist film as a permanent protective film.
This prevents solder from adhering to unnecessary parts when soldering electronic components to the printed wiring board, and 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-50-144431 and JP-A-51-40451 disclose:
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 having a reaction product obtained by reacting an unsaturated monocarboxylic acid with an epoxy resin and further adding a polybasic acid anhydride as a base polymer. . In addition, Tokiwa 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 resist pattern is formed, usually, for thermosetting, an epoxy resin is generally contained as a thermosetting component, and the carboxyl group of the side chain introduced into the epoxy acrylate is reacted with the epoxy group. In addition, a resist film having excellent adhesion, hardness, heat resistance, electrical insulation and the like is formed.

[0006]

However, in recent years,
In order to improve the productivity of printed wiring boards, it is required to improve the workability in a series of steps for providing a solder resist. After the film is exposed by applying a negative film for exposure, for example, when the negative film is peeled off, the film adheres and does not peel off, and the film does not peel off. It is also required that the so-called thermal management range, which is the control range of the thermal allowable limit of the degree of curing of the coating film that can be removed at the time of development, is wide, but the conventional solder resist composition described above sufficiently satisfies these requirements. Cannot be satisfied, and its improvement is required. The performance of the coating film for the above negative film,
The solder resist composition is applied to a printed circuit board and relates to the surface state after drying to the extent that the solvent is volatilized, and as a measure of dryness that the coating film does not adhere when the exposure film is brought into contact. The so-called touch dryness (the property that the coating does not stick even when pressed lightly with a human finger) has been tested, and in the current situation where the introduction of automatic exposure machines is increasing, it is necessary to improve this touch dryness. Is one of the important issues. When peeling the negative film by hand, it is possible to prevent the adhesion of the coating film while adjusting the peeling force,
When using an automatic exposure machine, the negative film is brought into contact with the coating film of the solder resist composition, and after the exposure, the separation is performed by supporting the negative film on a frame and moving the frame mechanically. In order to prevent damage to the coating film in any state, further improvement in dryness to the touch is required. As described above, recently, the solder resist composition is required to have improved sensitivity and improved touch dryness. It is sufficient to increase the amount of the monomer, but on the contrary, such a coating film is easily tacky before photo-curing and has poor dryness to the touch, so both are reciprocal in terms of the composition of the solder resist composition. It can be said that it is a performance, and not only a device for harmonizing it, but also a device for widening a range of heat management is required.
In addition, when the heat management width is narrow, that is, when the allowable range of temperature rise due to heat is narrow, the liquid solder resist composition is applied to a printed wiring board, and in the drying process of removing the solvent, the allowable range is exceeded. Due to the time or temperature, the resin composition of the coating film begins to cure, and then is exposed and developed.When exposed, the unexposed portion is difficult to be removed by the developing solution. This can cause problems.

A first object of the present invention is to form an image by exposure to ultraviolet light and development with a dilute aqueous alkaline solution, to have good dryness to the touch, to have good sensitivity, to have a wide range of heat management, and to further improve adhesion, An object of the present invention is to provide a photosensitive resin composition capable of giving a pattern excellent in heat resistance and chemical resistance. A second object of the present invention is to provide a printed wiring board having a cured film of a solder resist film of the photosensitive resin composition before or after mounting electronic components.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, (A) an active energy ray-curable resin having at least two ethylenically unsaturated bonds in one molecule. Resin, (C) photopolymerization initiator, (D) reactive diluent and (E) epoxy-based thermosetting compound,
(B) A photosensitive resin composition to which a compound having at least two allyl groups is added has excellent dryness to the touch, good sensitivity, a wide range of heat management, and furthermore excellent adhesion, heat resistance and chemical resistance. The present invention has been found to provide an excellent photosensitive resin film particularly suitable for a solder resist for producing a printed wiring board, and has accomplished the present invention. 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 compound having at least two allyl groups, (C)
An object of the present invention is to provide a photosensitive resin composition containing a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy-based thermosetting compound. In the present invention, (2) and (B) the compound having at least two allyl groups are at least one of triallyl isocyanurate, a homopolymer of triallyl isocyanurate, and a copolymer of triallyl isocyanurate. Before or after mounting an electronic component coated with a solder resist film having a cured film of the photosensitive resin composition of the above (1), (3) or (1) or (2). A printed wiring board is provided.

In the present invention, “(A) an active energy ray-curable resin having at least two ethylenically unsaturated bonds in one molecule” refers to, for example, a polyfunctional epoxy having two or more epoxy groups in the 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, the resulting hydroxyl group may be reacted with a polybasic acid or an anhydride thereof. Can be.

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, phenol novolak type epoxy resins such as bisphenol A type, bisphenol F type and bisphenol AD type, cresol novolak type epoxy resins such as o-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 resin, polyfunctional modified novolak type epoxy resin, phenols and aromatic aldehyde having phenolic hydroxyl group And condensate type epoxy resins. 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, 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 the polybasic acids without isolation, as a solution of the 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 0.2 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. The reaction is preferably performed at a ratio of 0.3 to 0.9 mol, more preferably 0.4 to 0.8 mol, from the viewpoint that a highly sensitive resin film is obtained at the time of exposure. If the amount is less than 0.2 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 same applies when a polybasic acid anhydride is used. The acid value of the polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin, which is a reaction product of the above polybasic acid or its anhydride with the unsaturated monocarboxylic oxide epoxy resin, is preferably from 60 to 300 mgKOH / g. The acid value of the reaction product can be adjusted depending on the amount of the polybasic acid or its anhydride 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. By reacting a glycidyl compound having one or more radically polymerizable unsaturated groups with an epoxy group, a radically polymerizable unsaturated group may be further introduced to obtain 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. High photosensitivity and excellent photosensitivity. Examples of the compound having one or more radically polymerizable unsaturated groups and an epoxy group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, and pentaerythritol triacrylate monoglycidyl ether. 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 thus-obtained photosensitive resin comprising the glycidyl compound-added polybasic acid-modified unsaturated monocarboxylic epoxy resin preferably has an acid value of 45 to 250 mgKOH / g.

In the present invention, “(B) a compound having at least two allyl groups” includes a monomer having at least two (two or more) allyl groups, and a monomer unit having at least two allyl groups. (Two or more) homopolymer or copolymer. For example, monomers such as diallyl ester dicarboxylic acid such as diallyl orthophthalate, diallyl isophthalate and diallyl terephthalate, triallyl cyanurate, tetramethylol methane tetraagrate and triallyl trimellitate, and homopolymers thereof (for example, A polymer of many monomers in which only one double bond is polymerized),
For example, a polymer of triallyl trimellitate (weight average molecular weight (Mw) is 2 × 10 ⁴ , ratio of weight average molecular weight to number average molecular weight (Mw / Mn = 1.8 (dispersion degree)),
Triallyl cyanurate polymer (Mw = 2.8 × 10
⁴ , Mw / Mn = 1.5). Further, at least two copolymers of these monomers, for example, triallyl cyanurate or triallyl isocyanurate and diallyl phthalate (diallyl of ortho, iso, terephthalic acid) Copolymer (at least one kind of ester) (weight average molecular weight: 15,000 to 18,000, Mw / Mn =
1.5 to 1.6, an iodine value of 65 to 70, a copolymerization molar ratio of 0: 1 to 1: 1, etc.), and a copolymer of triallyl cyanurate or triallyl isocyanurate with diallyl dicarboxylate. No. The weight average molecular weight of the homopolymer and the copolymer is 2,000 to
100,000 is preferred. If it is less than 2,000, the degree of improvement in dryness to the touch becomes low, and if it exceeds 100,000, the dilute alkali developability may decrease. Of these, triallyl isocyanurate or its homopolymer or copolymer is preferred.

The component (B) has at least two allyl groups.
May be used alone or at least two
Species (two or more) may be used in combination, and by using this component, especially the dryness to the touch and the adhesion of the coating film are improved. The content is generally selected in the range of 1 to 40 g per 100 g of the component (A). If the content is less than 1 g, the dryness to the touch may not be sufficiently exhibited, and if it exceeds 40 g, the developability may be deteriorated. Dryness to the touch, adhesion, thermosetting properties,
Considering the properties of the solder resist film and the like, the content of the component (B) is particularly preferably in the range of 10 to 20 g.

In the present invention, the component (A)
In addition to the component (B), by mixing with (C) a photopolymerization initiator, and (D) a reactive diluent, and further with (E) an epoxy-based thermosetting compound, The photosensitive resin composition of the present invention can be used, and can be suitably used, for example, as a solder resist composition for producing a printed wiring board. The “(C) photopolymerization initiator” is not particularly limited, and any conventionally known one can be used. Specifically, as typical examples, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether,
Benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane- 1-one, 1-hydroxycyclohexylphenyl ketone, 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,
-Ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone,
2,4 diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, ethyl P-dimethylaminobenzoate, and the like. These can be used alone or in combination of two or more. The amount of the photopolymerization initiator to be used is usually 0.5 to 0.5 g per 100 g of the active energy ray-curable resin of the component (A).
50 g. If the amount is less than 0.5 g, the photo-curing reaction of the active energy ray-curable resin of the component (A) becomes difficult to proceed. If the amount exceeds 50 g, the effect is not improved in spite of the added amount. It may be disadvantageous or the mechanical properties of the cured coating may be reduced. From the viewpoints of photocurability, economy, and mechanical properties of the cured coating film, the amount used is preferably 2.0 to 30 g.

The "(D) reactive diluent" is used in order to further enhance the photocuring of the photosensitive resin of the component (A) and 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 (Meth) acrylate, propionic acid-modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid-modified Reactive diluents such as pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and caprolactone-modified dipentaerythritol hexa (meth) acrylate.

The above-mentioned difunctional or polyfunctional reactive diluents of 2 to 6 functional groups can be used either individually or in a mixture of a plurality of diluents. The amount of the reactive diluent to be added is generally selected from the range of 2.0 to 40 g per 100 g of the active energy ray-curable resin of the component (A). The addition amount is 2.0
When the amount is less than g, sufficient photocuring cannot be obtained, and sufficient properties such as acid resistance and heat resistance of the cured coating film cannot be obtained.
If the addition amount exceeds 40 g, the tack becomes severe, the adhesion of the artwork film to the substrate is likely to occur at the time of exposure, and it becomes difficult to obtain the 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.

The above-mentioned "(E) epoxy thermosetting compound"
Is added in the photosensitive resin composition of the present invention in order to obtain a sufficiently tough coating film after post cure. Typical examples of this epoxy-based thermosetting compound include:
At least one epoxy group per molecule, preferably 2
Epoxy resins (including epoxy oligomers) having at least two epoxy groups are preferred. For example, bisphenol A type epoxy resin obtained by reacting bisphenol A and epichlorohydrin in the presence of alkali, epoxidized resin obtained by subjecting bisphenol A to formalin condensation reaction, and in these resins, bisphenol A Novolak type epoxy resin obtained by reacting epichlorohydrin with a novolak resin instead of a brominated bisphenol A (phenol novolak type epoxy resin, o-cresol novolak type epoxy resin, p-tert-butylphenol novolak type, etc.) ), Bisphenol F or bisphenol S epoxy resin obtained by reacting bisphenol F or bisphenol S with epochlorohydrin, cyclohexene oxide group, tricyclode N'okishido group, an alicyclic epoxy resin having such cyclopentene oxide group, phthalic acid diglycidyl ester,
Diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, diglycidyl-p
Glycidyl ester resins such as hygioxybenzoic acid and glycidyl dimer acid; glycidylamine resins such as tetraglycidyldiaminodiphenylmethane and triglycidyl-p-aminophenol; (propylene, polypropylene) glycol diglycidyl ether; polytetramethylene glycol diglycidyl Ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, resorcin diglycidyl ether, 1.6 hexanediol diglycidyl ether, (ethylene, propylene) glycol diglycidyl ether, sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, pentaerythritol Glycidyl ether resin such as polyglycidyl ether, Tris (2 3-epoxypropyl) isocyanurate, triglycidyl tris (2-hydroxyethyl) such as triglycidyl isocyanurate having a triazine ring such as a isocyanurate. These thermosetting compounds may be used alone or in combination of two or more.

The above-mentioned epoxy-based thermosetting compound further comprises a melamine compound, an imidazole compound,
A post-curing of the coating film can be promoted by using a known epoxy curing accelerator such as a phenol compound in combination. Dicyandiamide, derivatives thereof (N-substituted dicyandiamide derivatives (general formulas and specific examples described in JP-A-11-119429)) and their organic acid salts (organic acids such as polybasic carboxylic acids, phosphoric acid, and sulfuric acid) At least one kind of acid salt). By using this thermosetting compound together, various properties such as heat resistance, moisture resistance, electrical insulation, chemical resistance, acid resistance, solvent resistance, adhesion, flexibility, and hardness of the obtained resist film are improved. It is useful as a solder resist for printed wiring boards. This epoxy-based thermosetting compound is usually added at a ratio of 5 to 100 g with respect to 100 g of the active energy ray-curable resin of the component (A). If the addition amount is less than 5 g, a coated film having desired physical properties may not be obtained after post-curing, and if it exceeds 100 g, the photocurability of the component (A) may decrease. The amount of the thermosetting compound to be added is preferably 15 from the viewpoint of the properties of the coating film after the posuki cure and the photocurability of the component (A).
６０60 g.

In the photosensitive resin composition of the present invention, in addition to the above-mentioned components, if necessary, various additives, for example, a filler comprising an inorganic pigment such as silica, alumina, talc, calcium carbonate, barium sulfate, etc. And known coloring 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 lands of the circuit pattern, and ultraviolet light is irradiated thereon, and then the negative film is applied. The coating is developed by removing and removing the unexposed areas corresponding to the soldering lands with a dilute alkaline aqueous solution. As the dilute aqueous alkali solution used at this time, a 0.5 to 5% by mass aqueous sodium carbonate solution is generally used, but other alkalis can also be used. Then, the target solder resist film can be formed by performing post-curing for 10 to 60 minutes with a hot air circulation type dryer at 140 to 160 ° C. In this way, a printed wiring board covered 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.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to each component and its component ratio used in the examples described later, similar compounds selected from the above-mentioned compounds of each component, and the above-mentioned preferable ranges of each component ratio will be described later. The invention of the broader concept encompassing the embodiments described above can be configured. For example, as a component for obtaining the resin of the component (A), at least one of acrylic acid and methacrylic acid as a radical polymerizable unsaturated monocarboxylic acid, a novolak type epoxy resin as a polyfunctional epoxy resin, and a polybasic acid as a polyfunctional epoxy resin Phthalic acids can be mentioned. As the component (B), at least one of triallyl isocyanurate, a homopolymer thereof, and a copolymer thereof is used. This (B)
By using the component, it is possible to improve the dryness to the touch,
In addition, the film has good sensitivity, has a wide range of heat management, and can improve other coating properties such as adhesion.

[0025]

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. Production Example 1 of Resin (Photosensitive Resin as Component (A)) In ethyl carbitol acetate, the epoxy equivalent is 220, and has an average of 7 phenol residues and an epoxy group in one molecule. A reaction product obtained by reacting acrylic acid at a ratio of 1 mol with respect to 1 mol of an epoxy group of the cresol novolac type epoxy resin is reacted with tetrahydrophthalic anhydride at a ratio of 0.6 mol to obtain a photosensitive resin solution. Was manufactured. This photosensitive resin solution was a viscous liquid containing 50 parts by mass of ethyl carbitol acetate with respect to 100 parts by mass of the solid resin component, and the acid value of the resin component was 88 mgKOH / g.

Example 1 A homopolymer of triallyl isocyanurate (TAIC prepolymer (manufactured by Nippon Kasei Co., Ltd., weight average molecular weight: 5,000 to 500 g) was added to 100 g of the photosensitive resin solution obtained in Resin Production Example 1. 30,000)) 2 g, dipentaerythritol hexaacrylate (DPHA) 8 g,
2-Methyl-1- [4- (methylthio) phenyl] -2-
Morpholino-1-propan-1-one (trade name IC-
907) 5 g, silica 3 g, barium sulfate 30 g, triglycidyl isocyanurate 10 g, melamine 1 g, phthalocyanine green 1 g were mixed and dispersed with three rolls,
A photosensitive resin composition was prepared. Table 2 shows the results of examining the dryness of the coating of the photosensitive resin composition to the touch, sensitivity, heat control width, and coating film performance by the test methods described below.

Examples 2 to 4 As shown in Table 1, a photosensitive resin composition was prepared in the same manner as in Example 1 except that the amount of the TAIC prepolymer was changed. Table 2 shows the results of examining the dryness of the film to the touch, the sensitivity, the heat control width, and the coating film performance.

Comparative Examples 1-3 As shown in Table 1, in Example 1, no TAIC prepolymer was blended (Comparative Example 1), and instead of the TAIC prepolymer, 4 g of dipentaerythritol hexaacrylate (DPHA) was blended. (Comparative Example 2),
DPHA 8g and triglycidyl isocyanurate 15g
A photosensitive resin composition was prepared in the same manner except for the compound (Comparative Example 3), and the results of examining the dryness of the coating to the touch, sensitivity, thermal control width, and coating performance in the same manner as in Example 1 were shown. It is shown in FIG.

The methods for evaluating the dryness to the touch, sensitivity, thermal control width and coating film performance (adhesion, pencil hardness, acid resistance, solvent resistance, heat resistance) of the coating film of the photosensitive resin composition are as follows. It is as follows. (1) Dryness to the touch To the copper foil surface of the copper foil-laminated substrate, the above Examples 1-4,
Each photosensitive resin composition of Comparative Examples 1 to 3 was applied over the entire surface, dried at 80 ° C. for 20 minutes, and a finger was lightly pressed against the surface of the coating film, and the degree of sticking to the finger was evaluated according to the following criteria. ◎: No sticking at all ○: Almost no sticking Δ: Slightly sticking ×: Sticking (2) Sensitivity A substrate (copper-clad laminate), which has been subjected to surface treatment in advance, is screen-printed and used in Examples 1-4. Each of the photosensitive resin compositions of Comparative Examples 1 to 3 was applied to a thickness of 35 μm (before drying) to prepare each coated substrate, and each coated substrate was dried at 80 ° C. for 20 minutes. . A sensitivity measurement step tablet (21 steps Kodak) is set on the coated substrate, and the main peak is 365 n through the step tablet.
A test piece was obtained by irradiating an irradiation light amount of 300 mJ / cm ² with an irradiation light amount of ultraviolet light having a wavelength of m using an Oak Lighting Co., Ltd., using a 1% by weight aqueous solution of sodium carbonate.
After developing for 60 seconds at a spray pressure of 2.0 kg / cm ^2, the unremoved portion of the exposed portion was measured by a method (numerical step number). The sensitivity was represented by the obtained number. (3) Thermal Management Width The photosensitive resin compositions of Examples 1 to 7 and Comparative Examples 1 to 3 each having a thickness of 35 μm were applied to a substrate (copper-clad laminate) that had been surface-treated in advance by screen printing. (Before drying) to prepare each coated substrate, each coated substrate was 80 ° C., and the pre-drying time was extended every 10 minutes to 120 minutes as a test piece. % Of sodium carbonate aqueous solution and a spray pressure of 2.0 kg / cm ² for 60 seconds, and the longest pre-drying time (min) required to completely remove the coating film was measured. .

(4) Performance of coating film The photosensitive resin compositions of Examples 1 to 7 and Comparative Examples 1 to 3 were coated on a substrate (copper-clad laminate) which had been surface-treated in advance by a screen printing method. (Before drying) to prepare each coated substrate, and each coated substrate was dried at 80 ° C. for 20 minutes. A negative film was brought into close contact with the substrate, and after exposure, developed with a 1% by mass aqueous solution of sodium carbonate to form a pattern. Next, this substrate was thermally cured at 150 ° C. for 60 minutes to prepare a test piece having a cured coating film, and the coating film performance was evaluated.

(A) Adhesion The adhesion was measured by a grid test according to JIS D-0202. (B) Pencil hardness Measured in accordance with JIS K-5400 6.14. (C) Acid resistance A test piece having a cured coating film was immersed in a 10% by mass aqueous sulfuric acid solution at room temperature for 30 minutes, washed with water, and then subjected to a peeling test with a cellophane adhesive tape to observe peeling and discoloration of the coating film. The acid resistance was evaluated visually. ◎: No change observed ○: Slight change △: Notable change ×: Film swelled and peeled

(D) Solvent resistance A test piece having a cured coating film was immersed in methylene chloride at room temperature for 30 minutes, washed with water, and then subjected to a peeling test with a cellophane adhesive tape to observe peeling and discoloration of the coating film. The solvent resistance was evaluated visually. ◎: No change observed ○: Slight change △: Notable change ×: Coating swelled and peeled (e) Heat resistance Test piece having cured coating Was immersed in a solder bath at 260 ° C. for 30 seconds in accordance with the test method of JIS C 6481,
The peeling test using a cellophane tape was defined as one cycle, and the state of the coating film after performing a total of 1 to 3 cycles was visually evaluated. ◎: No change in coating film after 3 cycles. ○: Slight change after 3 cycles. ：: Change after 2 cycles. ×: Peeling after 1 cycle.

The electrical characteristics (insulation resistance and discoloration)
IPC-SM-840B B-25
Place a comb electrode B coubon at 60 ° C, 90% RH
When a DC voltage of 100 V was applied in a constant temperature and humidity chamber (relative humidity), the insulation resistance after 500 hours was measured, the discoloration was visually observed, and the electrical characteristics were evaluated. There was no discoloration or only slight discoloration, and the resistance value showed a value of 10 ¹¹ (Ω), which was inferior to those usually used.

[0034]

[Table 1]

[0035]

[Table 2]

From the results shown in Table 1, the dryness to the touch of the example is equivalent to that of Comparative Examples 1 to 3 regardless of whether it is superior or worse. Particularly, the TAIC prepolymer is 5 g or more. When used in a large amount, it is superior to any of the comparative examples. The heat management width, sensitivity, and adhesion are the same as those of the comparative examples 1 to 3 even if they are superior or worse, and the hardness, acid resistance, solvent resistance, and heat resistance are the same. Although there is no difference between the examples and the comparative examples, when all these items are comprehensively evaluated, it can be said that any of the examples is superior to any of the comparative examples. In the above-described invention, the “photosensitive resin composition” may be referred to as a “photosensitive resin composition for solder resist”, and further a use limitation of “excellent in touch dryness when drying a coating film” may be added. Well, it may be a "printed wiring board coated with a solder resist film and a method for manufacturing the same", or may be an invention to which the above-mentioned other numerical values and other limitations, and further a limitation combining any plural of these are added. .

[0037]

According to the present invention, an image can be formed by exposure to ultraviolet light and development with a dilute aqueous alkaline solution, the dryness to the touch is good, the sensitivity is good, and the heat management range is wide.
Further, it is possible to provide a photosensitive resin composition capable of providing a pattern excellent in heat resistance, electric insulation, chemical resistance and the like. And it is possible to provide a printed wiring board before or after mounting electronic components having a cured film of the solder resist film of the photosensitive resin composition, and has high resolution, high precision, and excellent cured coating film performance. Printed wiring board can be provided.

Continued on the front page (72) Inventor Hiromitsu Nogoku 16-2, Oaza Sayamagahara, Iruma-shi, Saitama F-term (reference) in Tamra Kaken Corporation 2H025 AA07 AA08 AA10 AA14 AA15 AB15 AC01 AD01 BC13 BC42 BC48 BC85 BC86 BD23 BD53 CA00 4J011 QA13 QA20 QA23 QA25 QA27 QB01 QB16 QB20 QB22 RA11 SA02 SA06 SA12 SA14 SA15 SA24 SA25 SA32 SA36 SA54 SA63 SA64 SA78 UA01 VA01 WA01 4J027 AA07 AA08 AE02 AE03 BA08 BA20 BA21 BA23 BA30 BA23 BA23 BA23 BA23 BA30 AB09 AB16 AB17 AD08 AD09 AD21 AF06 AG06 AG07 AH07 AJ09 DA02 DC31 DC41 DC45 FB01 JA09 5E314 AA27 AA32 CC01 CC07 DD07 FF19 FF21 GG17

Claims (3)

[Claims] 1. An active energy ray-curable resin having at least two ethylenically unsaturated bonds in one molecule, (B) a compound having at least two allyl groups,
A photosensitive resin composition containing (C) a photopolymerization initiator, (D) a reactive diluent, and (E) an epoxy-based thermosetting compound. 2. The compound according to claim 1, wherein the compound (B) having at least two allyl groups is at least one of triallyl isocyanurate, a homopolymer of triallyl isocyanurate, and a copolymer of triallyl isocyanurate. Photosensitive resin composition. 3. A printed wiring board before or after mounting an electronic component coated with a solder resist film having a cured film of the photosensitive resin composition according to claim 1 or 2.