JP2001026624A - Photosensitive resin, photosensitive resin composition and printed-wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin which is developable by ultraviolet irradiation or dilute aqueous alkaline solution, shows a wide range of heat control, i.e., a control of the thermal tolerance limit of the degree of cure of the unexposed part removable at development of a coated film when dried, shows a high sensitivity and is suitable for a solder resist in a printed-wiring board having an excellent heat resistance, electrical insulting property and chemical resistance, a photosensitive resin composition and a printed-wiring board. SOLUTION: A photosensitive resin is obtained by allowing a carboxy group, obtained by allowing at least a portion of epoxy groups in a polyfunctional epoxy resin to react with at least one chosen from an acrylic acid and a methacrylic acid and subsequently with at least one chosen from a polybasic acid and its anhydride, to react with a glycidyl compound (except for glycidyl acrylate and glycidyl methacrylate) having at least one unsaturated group within a molecule. A photosensitive resin composition contains this photosensitive resin. A printed-wiring board is prepared using this composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of forming an image by exposure to ultraviolet light and development with a dilute alkaline aqueous solution, and has a thermal allowable limit of the degree of curing of a coating film that can be removed during development of an unexposed portion when the coating film is dried. The so-called heat management range is wide, high sensitivity, and can provide a coating film excellent in heat resistance and chemical resistance, for example, a photosensitive resin suitable for a solder resist film for a printed wiring board, The present invention relates to a photosensitive resin composition and a printed wiring board using the same.

[0002]

2. Description of the Related Art Acrylate oligomers, including epoxy acrylate resins, are widely used in the industry because of their excellent photocuring properties. Among them, epoxy acrylate resins are widely used as a main component of metal coatings and solder resist coatings on printed wiring boards because epoxy acrylate resins have excellent adhesion, heat resistance, and chemical resistance as well as photocurability compared to other acrylate oligomers. Has been used. For example, a printed wiring board is for mounting a circuit pattern on a substrate by forming a pattern of a conductive circuit thereon and soldering electronic components to the soldering lands of the pattern. It is 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, solder resist films
It has been the mainstream to pattern the solution composition on a substrate by a screen printing method, dry the solvent composition after removing the solvent, and then cure it with 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:
The introduction of carboxyl groups into epoxy acrylates provides photosensitivity and developability in dilute aqueous alkaline solutions. Although workability and productivity are improved, demands for higher sensitivity Cannot be fully satisfied. As an improvement measure, Japanese Patent Laid-Open No. 11-242
No. 54 discloses a reaction product obtained by reacting polyfunctional epoxy resin with acrylic acid or methacrylic acid, and further adding glycidyl acrylate or glycidyl methacrylate to a carboxyl group generated by reacting polybasic acid anhydride. A liquid solder resist composition containing as a base polymer is disclosed.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
No. 254, the liquid solder resist composition,
A photosensitive resin composition that is highly sensitive and has excellent heat resistance, electrical insulation, and chemical resistance, and is suitable for a solder resist film for printed wiring boards. There is no direct description of the so-called thermal management width, which is the management of the allowable thermal limit of the degree of cure of the coating film that can be removed during development of the corresponding portion. If such a heat management width is narrow, that is, if the allowable range of temperature rise due to heat is narrow, the liquid solder resist composition is applied to a printed wiring board, and the drying process of removing the solvent exceeds the allowable range. When the resin composition of the coating film begins to cure due to the time or temperature, and then exposed and developed, the unexposed portion is difficult to be removed by the developing solution. May cause problems. The present invention clarifies that it is possible to widen the heat management range particularly for portions not explicitly described in Japanese Patent Application Laid-Open No. H11-24254, a photosensitive resin that clarifies its selectivity, Another object of the present invention is to provide a photosensitive resin having a novel structure which is not described in a gazette, a photosensitive resin composition as an application thereof, and a cured film adherend using the same.

A first object of the present invention is to provide a pattern which can form an image by exposure to ultraviolet light and development with a dilute aqueous alkaline solution, has high sensitivity, and is excellent in heat resistance, electrical insulation and chemical resistance. Japanese Unexamined Patent Application Publication No.
An object of the present invention is to provide a photosensitive resin having a novel structure which is not described in JP-A-1-24254. A second object of the present invention is to form an image by ultraviolet exposure and development with a dilute alkaline aqueous solution, to have a wide range of heat management, high sensitivity, and excellent heat resistance, electrical insulation and chemical resistance. Another object of the present invention is to provide a photosensitive resin capable of giving a patterned pattern. A third object of the present invention is to provide a photosensitive resin composition suitable as a solder resist for a printed wiring board, for example. A fourth object of the present invention is to provide a printed wiring board having a cured film of the solder resist film before or after mounting electronic components.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that a resin having a radical polymerizable unsaturated group and a carboxyl group has at least one unsaturated compound per molecule. A photosensitive resin obtained by reacting a glycidyl compound having a saturated group (one or more unsaturated groups) is excellent in developability with a dilute alkaline aqueous solution, has a wide range of heat management, has good photosensitive characteristics, and has development resistance. The present invention has been found to provide a photosensitive resin having excellent heat resistance and chemical resistance. That is, the present invention provides (1) reacting at least a part of the epoxy group of the polyfunctional epoxy resin with a radically polymerizable unsaturated monocarboxylic acid, and further reacting at least one of a polybasic acid and a polybasic anhydride. A glycidyl compound having at least one unsaturated group in one molecule (excluding glycidyl acrylate or glycidyl methacrylate) is reacted with the carboxyl group of the polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin produced by the reaction. Another object of the present invention is to provide a photosensitive resin to be obtained or another photosensitive resin having the same high molecular structure in the main part as the photosensitive resin. The present invention also provides (2) reacting at least a part of the epoxy group of the polyfunctional epoxy resin with a radically polymerizable unsaturated monocarboxylic acid, and further reacting at least one of a polybasic acid and a polybasic acid anhydride. A photosensitive resin obtained by reacting a glycidyl compound having at least one unsaturated group in one molecule with a carboxyl group of a polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin produced by the reaction,
0.05 to 0.9 mol of a glycidyl compound having at least one unsaturated group in one molecule (0.05 to 0.9 mol in the case of glycidyl acrylate or glycidyl methacrylate) per mol of carboxyl group of the polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin. 0.3 mol), or another photosensitive resin having the same high molecular structure in the main part as the photosensitive resin obtained from the reaction, (3), polybasic acid-modified unsaturated monocarboxylic acid. The epoxy resin reacts 0.7 to 1.2 equivalents of a radical polymerizable unsaturated monocarboxylic acid with respect to 1 equivalent of the epoxy group of the polyfunctional epoxy resin, and further reacts a polybasic acid and a polybasic acid with respect to 1 mol of the hydroxyl group of the reaction product. The photosensitive resin according to the above (1) or (2), which is a resin obtained by reacting at least one of basic acid anhydrides in a ratio of 0.3 to 1.0 mol; 4), any one of photosensitive resin, of from the acid value of the photosensitive resin is the above (1) to a 45~140 mgKOH / g (3) (5), (1) to (4)
A photosensitive resin composition containing any of the photosensitive resins,
(6) An object of the present invention is to provide 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 of the above (5).

In the present invention, the radical polymerizable unsaturated monocarboxylic acid is allowed to react with at least a part of the epoxy group of the polyfunctional epoxy resin in the above (1), and at least a polybasic acid and a polybasic acid anhydride are further reacted. A glycidyl compound (excluding glycidyl acrylate or glycidyl methacrylate) having at least one unsaturated group in one molecule to a carboxyl group of a polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin produced by reacting one of them. The "photosensitive resin obtained by the reaction" refers to a photosensitive resin obtained by using an example of the reaction mode, and "the other photosensitive resin having the same polymer structure in the main part as the photosensitive resin." The term “resin” means that if the polymer structure of the photosensitive resin obtained as a result is the same in the main part, the reaction of the raw material Order, regardless of the reaction form of the kind of raw material, is an indication that the technical scope of the present invention. The term “same in the main part” includes a case where the product has a common polymer structure which can be said to be substantially the same as the product involving all the raw materials specified in the above (1). The same applies to the relevant part of the invention (2). The “photosensitive resin or the photosensitive resin and the main part” may be referred to as the “photosensitive resin and the main part”, and the subsequent “other” may be deleted.

In the present invention, any polyfunctional epoxy resin can be used as long as it is a difunctional or higher functional epoxy resin, and there is no particular limitation on the epoxy equivalent, but it is usually 1,000 or less, preferably 100 to 100. Use the one with 500. For example, bisphenol A type, bisphenol F
Type, bisphenol AD type, phenol novolak type,
о-Cresol novolak type epoxy resin such as cresol novolak type, bisphenol A novolak type
Cycloaliphatic epoxy resin, glycidyl ester resin,
Glycidylamine resins, heterocyclic epoxy resins and the like can be mentioned. 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.

Next, 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. If the epoxy group is excessive, gelation may occur during the synthesis reaction in the subsequent step, or the stability of the resin may be reduced. In addition, if the radical polymerizable unsaturated monocarboxylic acid is excessive, a large amount of unreacted carboxylic acid remains, so that various properties of the cured product (for example, water resistance, etc.)
May be reduced. 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.

Further, at least one of a polybasic acid and an anhydride of a polybasic acid (hereinafter referred to as polybasic acid) is added to the unsaturated monocarboxylic oxide epoxy resin which is a reaction product of the above epoxy resin and a radical polymerizable unsaturated monocarboxylic acid. Basic acids). There is no particular limitation on the polybasic acid, and any of saturated and unsaturated acids can be used. Examples of such polybasic acids include succinic acid, maleic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid , Trimellitic acid, pyromellitic acid, etc., and the anhydrides of polybasic acids include these anhydrides. These compounds can be used alone or in combination of two or more. The polybasic acids react with the hydroxyl groups 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 acids to be reacted is desirably 0.3 to 1.0 mol with respect to 1 mol of the hydroxyl group of the reaction product of the epoxy resin and the radically polymerizable unsaturated monocarboxylic acid. In order to obtain a highly sensitive resin film at the time of exposure, the reaction is preferably performed at a ratio of 0.4 to 1.0, 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. Polybasic acids are added to the above unsaturated monocarboxylic oxide epoxy resin and reacted, and the reaction is preferably performed in a heated state.
The temperature is preferably from 0 to 130 ° C. Reaction temperature 130 ° C
When it exceeds, the one bonded to the epoxy resin and the radical polymerizable unsaturated group of the unreacted monomer may easily cause thermal polymerization and synthesis may be difficult, and at 70 ° C. or lower, the reaction rate becomes slow, It is not 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 acids and the unsaturated monocarboxylic oxide epoxy resin, is preferably from 60 to 160 mgKOH / g. The acid value of the reaction product can be adjusted by the amount of the polybasic acids to be reacted.

In the present invention, a glycidyl compound having one or more radically polymerizable unsaturated groups and an epoxy group is reacted with a carboxyl group of the above polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin, A radically polymerizable unsaturated group is further introduced to obtain the photosensitive resin of the present invention. The photosensitive resin of the present invention has a high photopolymerization reactivity because the radical polymerizable unsaturated group is bonded to the side chain of the polymer skeleton of the photosensitive resin by the reaction of the last glycidyl compound, and has excellent photosensitive characteristics. Can have. 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-mentioned polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin and allowed to react. Usually, the amount of the glycidyl compound is 0.05 to 0.1 mol per 1 mol of carboxyl groups introduced into the resin.
The reaction is carried out at a ratio of 9 mol. 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 width of heat management and the electrical insulation, preferably 0.05 to 0.5. It is advantageous to carry out the reaction in a molar proportion, more preferably in a proportion of 0.1 to 0.5 mol. However, in the case of glycidyl acrylate or glycidyl methacrylate, the amount is 0.05 mol or more and less than 0.3 mol. The reaction temperature is preferably from 80 to 120C. The thus-obtained photosensitive resin comprising the glycidyl compound-added polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin preferably has an acid value of 45 to 140 mgKOH / g.

The photosensitive resin of the present invention can be used by mixing it with a photopolymerization initiator and a reactive diluent and, if necessary, a thermosetting compound such as an epoxy compound. The composition can be used as a solder resist composition for producing a printed wiring board. The photopolymerization initiator is not particularly limited, and any conventionally known photopolymerization initiator 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-phenylpropan-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, 2-ethylanthraquinone, 2-tert-butylanthraquinone,
2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4 diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, ethyl P-dimethylaminobenzoate, etc. Is mentioned. These can be used alone or in combination. The amount of the photopolymerization initiator used is usually 0.1 to 100 parts by weight of the photosensitive resin.
5 to 50 parts by weight. If the amount is less than 0.5 part by weight, the photo-curing reaction of the photosensitive resin hardly proceeds. The mechanical properties of the cured coating may decrease. From the viewpoint of photocurability, economy, mechanical properties of the cured coating film, the amount used is preferably 2.0 to
30 parts by weight.

The reactive diluent is used to further enhance the photocuring of the photosensitive resin to obtain a coating film having acid resistance, heat resistance, alkali resistance, etc. Compounds having at least two heavy bonds are 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
Acrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, ethylene oxide-modified phosphate di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dimethyl Pentaerythritol tri (meth) acrylate, propionic acid-modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propion Acid-modified dipentaerythritol penta (meth) acrylate,
Dipentaerythritol hexa (meth) acrylate,
And reactive diluents such as caprolactone-modified dipentaerythritol hexa (meth) acrylate.

The above difunctional or hexafunctional or other polyfunctional reactive 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 parts by weight with respect to 00 parts by weight.
If the addition amount is less than 2.0 parts by weight, sufficient photocuring cannot be obtained, sufficient characteristics such as acid resistance and heat resistance of the cured coating film cannot be obtained, and the addition amount exceeds 40 parts by weight. In addition, the artwork film tends to adhere to the substrate during exposure, and it becomes difficult to obtain a desired cured coating film. 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 addition amount of the reactive diluent is preferably 4.0 to 20 parts by weight.

In the photosensitive resin composition of the present invention, it is also preferable to add a thermosetting compound in order to obtain a sufficiently tough coating film after post-curing. Representative examples of the thermosetting compound include, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin,
Bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, alicyclic epoxy resin, (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,
Two or more epoxies in one molecule such as sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, pentaerythritol polyglycidyl ether, tris (2,3-epoxypropyl) isocyanurate, triglycidyl tris (2-hydroxyethyl) isocyanurate, etc. Epoxy compounds having a group are preferred. These thermosetting compounds may be used alone or in combination of two or more.

The thermosetting compound can be used in combination with a known epoxy curing accelerator such as a melamine compound, an imidazole compound or a phenol compound as a reaction accelerator to promote post-curing of the coating film. The combined use of this thermosetting compound can improve various properties such as heat resistance, acid resistance, solvent resistance, adhesion, and hardness of the obtained resist film, and is useful as a solder resist for a printed wiring board. . The thermosetting compound is usually added at a ratio of 2 to 40 parts by weight based on 100 parts by weight of the photosensitive resin. If the amount is less than 2 parts by weight, a coated film having desired physical properties may not be obtained after post-curing, and if it exceeds 40 parts by weight, the photocurability of the photosensitive resin may be reduced. The amount of the thermosetting compound to be added is preferably 4 to 20 parts by weight from the viewpoints of physical properties of the coated film after photo sclerosis and photocurability of the photosensitive resin.

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 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-transmitting 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. In this case, a 0.5 to 5% by weight aqueous solution of sodium carbonate is generally used as a dilute aqueous alkali solution, but other alkalis can also 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 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. In addition, specific examples, mixing amounts, usage methods, etc. of the respective components used by mixing are described in Japanese Patent Application No. 11-6795.
No. 3 can be applied.

[0022]

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, 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, phthalic anhydrides as a polybasic acid (anhydride), and an ethylenic compound as a glycidyl compound A glycidyl compound having 1 to 3 vinyl groups and one glycidyl group as a bond can be exemplified.

[0023]

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 In 250 parts by weight of carbitol acetate, 220 parts by weight of a cresol novolak type epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., ESCN-220, epoxy equivalent 220) and 64.8 parts by weight of acrylic acid were dissolved and reacted under reflux to produce cresol. A novolak type epoxy acrylate was obtained. Next, 123.2 parts by weight of hexahydrophthalic anhydride was added to the epoxy acrylate, and the mixture was reacted under reflux until the acid value reached the theoretical value.After that, 57.6 parts by weight of pentaerythritol triacrylate monoglycidyl ether was added, and further reacted. Solids 65
By weight, a photosensitive resin was obtained.

Production Example 2 In 250 parts by weight of carbitol acetate, 220 parts by weight of a cresol novolak type epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., ESCN-220, epoxy equivalent: 220) and 64.8 parts by weight of acrylic acid were dissolved and reacted under reflux. Thus, a cresol novolak type epoxy acrylate was obtained. Next, 92.4 parts by weight of hexahydrophthalic anhydride was added to the epoxy acrylate, and the mixture was reacted under reflux until the acid value reached the theoretical value.After that, 19.2 parts by weight of pentaerythritol triacrylate monoglycidyl ether was added, and further reacted. Solids 61
By weight, a photosensitive resin was obtained.

Production Example 3 In 250 parts by weight of carbitol acetate, 220 parts by weight of a cresol novolak type epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., ESCN-220, epoxy equivalent: 220) and 64.8 parts by weight of acrylic acid were dissolved and reacted under reflux. Thus, a cresol novolak type epoxy acrylate was obtained. Next, 92.4 parts by weight of hexahydrophthalic anhydride was added to the epoxy acrylate, and the mixture was reacted under reflux until the acid value reached the theoretical value. Then, 14.2 parts by weight of glycidyl methacrylate was added, and further reacted to obtain a solid content of 61% by weight. Was obtained.

Production Example 4 In 250 parts by weight of carbitol acetate, 220 parts by weight of a cresol novolak type epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., ESCN-220, epoxy equivalent: 220) and 64.8 parts by weight of acrylic acid were dissolved and reacted under reflux. Thus, a cresol novolak type epoxy acrylate was obtained. Next, 138.6 parts by weight of hexahydrophthalic anhydride was added to the epoxy acrylate, and the mixture was reacted under reflux until the acid value reached the theoretical value. Then, 56.8 parts by weight of glycidyl methacrylate was added, and further reacted to obtain a solid content of 66% by weight. Was obtained.

Production Example 5 In 250 parts by weight of carbitol acetate, 220 parts by weight of a cresol novolac type epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., ESCN-220, epoxy equivalent: 220) and 72 parts by weight of acrylic acid were dissolved and reacted under reflux. Thus, a cresol novolak type epoxy acrylate was obtained. Then, 15.2 parts by weight of hexahydrophthalic anhydride was added to the epoxy acrylate,
The reaction was carried out under reflux until the acid value reached the theoretical value.
By weight, a photosensitive resin was obtained.

Production Example 6 In 250 parts by weight of carbitol acetate, 220 parts by weight of a cresol novolak type epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., ESCN-220, epoxy equivalent: 220) and 72 parts by weight of acrylic acid were dissolved and reacted under reflux. Thus, a cresol novolak type epoxy acrylate was obtained. Next, 136.8 parts by weight of hexahydrophthalic anhydride was added to the epoxy acrylate, and the mixture was reacted under reflux until the acid value reached the theoretical value to obtain a photosensitive resin having a solid content of 63% by weight.

Example 1 2- 100 parts by weight of the photosensitive resin obtained in Production Example 1
8.0 parts by weight of methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 8.0 parts by weight of trimethylolpropane triacrylate, and triglycidyl tris (2-hydroxyethyl) isocyanurate
8.0 parts by weight, 0.5 part by weight of phthalocyanine green and 8.0 parts by weight of talc were blended, and these were mixed and dispersed with three rolls to prepare a solution of the photosensitive resin composition. Table 1 shows the results obtained by examining the sensitivity and the coating film performance of this photosensitive resin composition by the test methods described below.

Example 2 2- 100 parts by weight of the photosensitive resin obtained in Production Example 1
8.0 parts by weight of methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 0.8 parts by weight of diethylthioxanthone, 8.0 parts by weight of trimethylolpropane triacrylate, 8.0 parts by weight of triglycidyl tris (2-
8.0 parts by weight of (hydroxyethyl) isocyanurate, 0.5 parts by weight of phthalocyanine green and 8.0 parts by weight of talc were mixed, and these were mixed and dispersed with three rolls to prepare a solution of a photosensitive resin composition. Table 1 shows the results obtained by examining the sensitivity and the coating film performance of this photosensitive resin composition in the same manner as in Example 1.

Example 3 2- 100 parts by weight of the photosensitive resin obtained in Production Example 2
8.0 parts by weight of methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 0.8 parts by weight of diethylthioxanthone, 8.0 parts by weight of trimethylolpropane triacrylate, 8.0 parts by weight of triglycidyl tris (2-
8.0 parts by weight of (hydroxyethyl) isocyanurate, 0.5 parts by weight of phthalocyanine green and 8.0 parts by weight of talc were mixed, and these were mixed and dispersed with three rolls to prepare a solution of a photosensitive resin composition. The sensitivity and coating film performance of this photosensitive resin composition were examined in the same manner as in Example 1, and the results are shown in Table 1.

Example 4 2- 100 parts by weight of the photosensitive resin obtained in Production Example 3
8.0 parts by weight of methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 0.8 parts by weight of diethylthioxanthone, 8.0 parts by weight of trimethylolpropane triacrylate, 8.0 parts by weight of triglycidyl tris (2-
8.0 parts by weight of (hydroxyethyl) isocyanurate, 0.5 parts by weight of phthalocyanine green and 8.0 parts by weight of talc were mixed, and these were mixed and dispersed with three rolls to prepare a solution of a photosensitive resin composition. The sensitivity and coating film performance of this photosensitive resin composition were examined in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 100 parts by weight of the photosensitive resin obtained in Production Example 4 was
8.0 parts by weight of methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 0.8 parts by weight of diethylthioxanthone, 8.0 parts by weight of trimethylolpropane triacrylate, 8.0 parts by weight of triglycidyl tris (2-
8.0 parts by weight of (hydroxyethyl) isocyanurate, 0.5 parts by weight of phthalocyanine green and 8.0 parts by weight of talc were mixed, and these were mixed and dispersed with three rolls to prepare a solution of a photosensitive resin composition. The sensitivity and coating film performance of this photosensitive resin composition were examined in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2 100 parts by weight of the photosensitive resin obtained in Production Example 5 was
8.0 parts by weight of methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 8.0 parts by weight of trimethylolpropane triacrylate, and triglycidyl tris (2-hydroxyethyl) isocyanurate
8.0 parts by weight, 0.5 part by weight of phthalocyanine green and 8.0 parts by weight of talc were blended, and these were mixed and dispersed with three rolls to prepare a solution of the photosensitive resin composition. The sensitivity and coating film performance of this photosensitive resin composition were examined in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 3 2- 100 parts by weight of the photosensitive resin obtained in Production Example 6
8.0 parts by weight of methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 0.8 parts by weight of diethylthioxanthone, 8.0 parts by weight of trimethylolpropane triacrylate, 8.0 parts by weight of triglycidyl tris (2-
8.0 parts by weight of (hydroxyethyl) isocyanurate, 0.5 parts by weight of phthalocyanine green and 8.0 parts by weight of talc were mixed, and these were mixed and dispersed with three rolls to prepare a solution of a photosensitive resin composition. The sensitivity and coating film performance of this photosensitive resin composition were examined in the same manner as in Example 1, and the results are shown in Table 1.

The method of evaluating the photosensitive resin composition and coating film performance (solder heat resistance, chemical resistance, solvent resistance, and electrical characteristics) is as follows.
It is as follows. The coating film performance was determined by applying the photosensitive resin composition of each of Examples 1 to 4 and Comparative Examples 1 to 3 to a substrate (copper-clad laminate) that had been surface-treated in advance by a screen printing method to a thickness of 35 μm ( (Before drying) to prepare each coated substrate.
After pre-drying for 1 minute, irradiate with ultraviolet light at an exposure of 600 mJ / cm ² , develop with 1% aqueous solution of sodium carbonate for 60 seconds, and cure the coating by post-curing at 150 ° C. for 30 minutes. Make a piece,
The coating film of each test piece was evaluated.

Sensitivity A step tablet for sensitivity measurement (Kodak 21-stage) is placed on the pre-dried coated substrate, and the main peak is passed through the step tablet to reduce the amount of irradiation of ultraviolet light having a wavelength of 365 nm manufactured by Oak Manufacturing Co., Ltd. 300mJ / c using integrated light meter
After irradiation with m ² , the test piece was used as a test piece, and a 1% by weight aqueous solution of sodium carbonate was used for development for 60 seconds at a spray pressure of 2.0 kg / cm ^2. Number). The larger the number of steps, the better the photosensitive characteristics.

Solder heat resistance A coated substrate having a cured coating film is immersed in a solder bath at 260 ° C. for 30 seconds in accordance with the test method of JIS C 6481, and then a peeling test with a cellophane tape is performed in one cycle, for a total of 1 to 3 cycles After performing the above, the state of the coating film was visually evaluated. ◎: No change in the coating film after 3 cycles. ：: Only slight change after 3 cycles. Δ: Change after 2 cycles. ×: Peeling after 1 cycle.

The coated substrate having the acid-resistant cured coating film was immersed in a 10% by weight 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 the peeling and discoloration of the coating film. The acid resistance was evaluated. ◎: No change is observed ○: Slight change Δ: Notable change ×: Coating swells and peels

Solvent Resistance A coated substrate having a cured coating film is treated with methylene chloride at room temperature for 30 minutes.
After immersion for a minute, after washing with water, a peeling test was carried out with a cellophane adhesive tape, and the peeling and discoloration of the coating film were observed to evaluate the solvent resistance. ◎: No change observed ○: Slight change △: Notable change ×: Film swelled and peeled

Electrical Characteristics (Insulation Resistance and Discoloration) A comb-shaped electrode of an IPC-SM-840B B-25 test coupon is placed on the cured coating film, and the voltage is set to 100 V in a constant temperature and humidity chamber at 60 ° C. and 90% RH (relative humidity). DC voltage of
The insulation resistance and discoloration after 500 hours were evaluated. ◎: Not discolored at all ：: Thinly discolored △: Notably discolored ×: Black scorched

Thermal management width In the step of preparing a coated substrate for preparing a test piece for examining the coating film performance described above, the coated substrate obtained by extending the predrying time to 120 minutes at intervals of 10 minutes is used. And 1
2.0 kg / c using an aqueous solution of sodium carbonate
Development was performed at a spray pressure of m ² for 60 seconds, and the longest pre-drying time (min) required to completely remove the coating film was measured.

[0043]

[Table 1]

From the results in Table 1, it can be seen that Examples 1 to 3 using the photosensitive prepolymers of Production Examples 1 and 2 using a glycidyl compound having three unsaturated groups, and glycidylyl having one unsaturated group. The product of Example 4 using the photosensitive resin of Production Example 3 using the compound is excellent in any performance. In particular, the heat management width of Example 3 using the same glycidyl compound and Comparative Example 1 using the photosensitive resin of Production Example 4 showed that the amount of the carboxyl group of the polybasic acid (anhydride) -modified epoxy acrylate was 1 The former is 0.1
By using 7 mol and using 0.44 mol of the latter, the former is about 1.8 times better and the selective effect of the amount used can be seen. Production Example 5 using no glycidyl compound,
Comparative Examples 2 and 3 using the photosensitive resin of No. 6 showed poor development in Comparative Example 2 in which the amount of the polybasic anhydride used was small, and the amount used was the same as that in Production Example 4. Even
In Comparative Example 3 in which the glycidyl compound was not used, it can be seen that those of Examples 1 to 4 were excellent in electrical characteristics by nearly three orders of magnitude, and 10 to 20% in thermal management width. In the above-described invention, the “photosensitive resin (composition)” may be referred to as “photosensitive resin for solder resist (composition)”,
In addition, "It is possible to remove the unexposed portions when developing the coating film during development (or to have excellent developability (in terms of resolution and accuracy)).
A wide range of thermal management, which is the management of the thermal allowable limit of the degree of cure of the coating film, may be added, or a “printed wiring board coated with a solder resist film and a method of manufacturing the same” may be added. The invention may be added with the above-mentioned numerical values and other limitations, and further, a limitation in which an arbitrary plurality of these is combined.

[0045]

According to the present invention, it is possible to provide a pattern which is capable of forming an image by ultraviolet exposure and development with a dilute alkaline aqueous solution, has high sensitivity, and is excellent in heat resistance, electrical insulation and chemical resistance. JP-A-11-2
It is possible to provide a photosensitive resin having a novel structure not described in JP-A-4254 and a composition thereof. Further, the present invention can form an image by ultraviolet exposure and development with a dilute alkaline aqueous solution, has a wide range of heat management, is highly sensitive, and has a pattern excellent in heat resistance, electrical insulation and chemical resistance. A photosensitive resin and a composition thereof that can be provided can be provided. Further, the present invention can provide a photosensitive resin composition having the above-mentioned performance and suitable as, for example, a solder resist for a printed wiring board. Further, the present invention can provide a printed wiring board before or after mounting electronic components, having the cured film of the solder resist film for the printed wiring board.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ichiro Miura 16-2 Oyama Sayamagahara, Iruma City, Saitama Prefecture Inside Tamra Kaken Co., Ltd. (72) Inventor Naoya Kakiuchi 16-2 Oyama Sayamahara, Iruma City, Saitama Prefecture F-term in Tamura Kaken Corporation (reference) 2H025 AA01 AA06 AA07 AA08 AA10 AA20 AB15 AC01 AD01 BC42 BC43 BC74 BC81 BC85 CA01 CA27 CC17 CC20 FA03 FA17 4J002 CD003 CD201 CH052 EE026 EE056 EH077 EJ016 EN006 EU236 EV316 FD 146 AE01 AE02 AE03 AE04 AE05 AE07 AJ05 AJ08 BA19 BA23 BA24 BA26 CA10 CA11 CA36 CB10 CC02 CC05 CD10 4J100 AL08P AL66P AL67P BA02P BA03P BA15P BA16P BC04P JA37 JA38 5E314 AA27 AA32 AA42 GG03 GG01 DD06

Claims (6)

[Claims] 1. A polyfunctional epoxy resin produced by reacting at least a part of epoxy groups of a polyfunctional epoxy resin with a radically polymerizable unsaturated monocarboxylic acid, and further reacting at least one of a polybasic acid and a polybasic anhydride. Photosensitive resin obtained by reacting a glycidyl compound having at least one unsaturated group in one molecule (excluding glycidyl acrylate or glycidyl methacrylate) with a carboxyl group of a polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin Or another photosensitive resin having the same high molecular structure in the main part as the photosensitive resin. 2. A polyfunctional epoxy resin produced by reacting at least a part of epoxy groups of a polyfunctional epoxy resin with a radically polymerizable unsaturated monocarboxylic acid, and further reacting at least one of a polybasic acid and a polybasic acid anhydride. A photosensitive resin obtained by reacting a glycidyl compound having at least one unsaturated group in one molecule with a carboxyl group of a polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin,
0.05 to 0.9 mol of a glycidyl compound having at least one unsaturated group in one molecule (0.05 to 0.9 mol in the case of glycidyl acrylate or glycidyl methacrylate) per mol of carboxyl group of the polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin. 0.3 mol), or another photosensitive resin having the same high molecular structure in the main part as the photosensitive resin obtained by the reaction. 3. The polybasic acid-modified unsaturated monocarboxylic oxide epoxy resin is used in an amount of from 0.7 to 0.7 equivalents of the radical polymerizable unsaturated monocarboxylic acid to 1 equivalent of the epoxy group of the polyfunctional epoxy resin.
3. A resin obtained by reacting 1.2 equivalents and further reacting at least one of a polybasic acid and a polybasic acid anhydride in a ratio of 0.3 to 1.0 mol per mol of hydroxyl group of the reaction product. The photosensitive resin according to the above. 4. The photosensitive resin according to claim 1, wherein the photosensitive resin has an acid value of 45 to 140 mgKOH / g. 5. A photosensitive resin composition containing the photosensitive resin according to claim 1. 6. 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 5.