JP3434584B2 - Resin composition, permanent resist resin composition and cured product thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition useful as a permanent resist for printed wiring boards and a cured product thereof.

[0002]

2. Description of the Related Art Conventionally, a printed wiring board has been manufactured by a subtractive method in which a copper clad laminate is used and an unnecessary portion of a circuit of a copper foil is removed by etching. This subtractive method is a fine pattern, It is difficult to form a high-density wiring board, and there are drawbacks such as small diameter through holes and via holes that cannot be uniformly formed by electroplating. It is the current situation.

On the other hand, recently, a full additive method has been attracting attention, in which an adhesive layer is formed on a laminated plate made of an insulating base material, and a circuit and a through hole are formed thereon by electroless plating. In this method, the accuracy of the conductor pattern is determined only by the transfer accuracy of the plating resist, and since the conductor part is formed only by electroless plating, even through-holes with high throwing power and even through-holes can be formed even on substrates with high aspect ratio through-holes. It is possible to perform plating. The additive method, which has been considered to be suitable for general consumers until now, has begun to be put into practical use as an industrial, high-density, high-multilayer substrate manufacturing process.

[0004]

Generally, in the additive method for manufacturing a substrate for consumer use, the plating resist pattern is transferred by the screen printing method. However, in order to manufacture a printed wiring board having high-density wiring, ,
It becomes necessary to form a plating resist pattern by photolithography, that is, to adopt a photoadditive method using a photoresist. Photoresist suitable for photoadditive method has sensitivity, resolution,
In addition to the original characteristics of photoresist such as developability, the following characteristics are required. Development is limited to 1,1,1-trichloroethane organic solvent or alkaline aqueous solution. Withstands electroless plating that is performed under high temperature and high alkaline conditions for a long time, has excellent solder resist characteristics as a permanent resist after plating, 260 in the soldering process
It has heat resistance that can withstand temperatures around ℃ and solvent resistance to organic solvents that clean the flux used during soldering, and that it does not reduce the thermal reliability of the entire substrate even when laminated. . At present, photoresists that can be used in this additive method are also on the market, but it is still insufficient.

Therefore, it is an object of the present invention that a resist having a high pattern accuracy can be formed by a photographic method by development using an alkaline aqueous solution, and the resist can sufficiently withstand the electroless copper plating solution of the full additive method, and A permanent resist resin composition having heat resistance that can withstand temperatures around 260 ° C during the soldering process and solvent resistance to organic solvents that wash the flux used during soldering, and that can be used without removing the final product. The present invention is to provide a cured product and a cured product thereof.

[0006]

In order to achieve the above object, a resin composition, a permanent resist resin composition for a printed wiring board and a cured product thereof according to the present invention have the following composition and are used as a permanent resist. And the ability to produce a printed wiring board using this resist resin composition.

That is, the present invention comprises the following components (a),
The present invention relates to a resin composition comprising (b), (c), (d) and (e), a permanent resist resin composition for a printed wiring board, and a cured product thereof. (A) Polyfunctional epoxy resin having an epoxy equivalent of 120 to 500, (b) obtained by reacting an alkylphenol novolac and an acrylate or methacrylate having a glycidyl group, and one or more acryloyl group or methacryloyl group and one in one molecule. Alkylphenol novolac type photothermosetting agent having the above phenolic hydroxyl group, (c) epoxy acrylate or epoxy methacrylate compound having a carboxyl group having an acid value of 5 to 100 , (d) photopolymerization and thermoreactive monomer (E) A photopolymerization initiator.

The epoxy resin of the component (a) used in the present invention is preferably a bisphenol A type (or F type) epoxy resin, and when the average molecular weight is more than 1000, it is preferable in terms of developability using an alkaline aqueous solution. Absent.

The alkylphenol novolac-type photothermosetting agent having at least one acryloyl group or methacryloyl group as the component (b) is usually obtained by reacting an alkylphenol novolac with an acrylate or methacrylate having a glycidyl group. In order to obtain a permanent resist having good pattern accuracy and excellent in alkali developability by photopolymerization, 0.2 to 0.6 equivalent of epoxy group of acrylate or methacrylate having glycidyl group is equivalent to 1 equivalent of hydroxyl group of alkylphenol novolac. Appropriate. As the acrylate or methacrylate having a glycidyl group, for example, glycidyl acrylate and glycidyl methacrylate are preferable because of their reactivity and availability. The alkyl group of the alkylphenol novolac preferably has about 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-butyl group, a sec-butyl group, and t.
An ert-butyl group, an allyl group and the like are not preferred because the lipophilicity is increased and the alkali developability is increased when the carbon number is 5 or more.

(C) The epoxy acrylate or epoxy methacrylate compound is not particularly limited, but includes bisphenol A type epoxy compound, bisphenol F type epoxy compound, bisphenol S type epoxy compound, phenol novolac type epoxy compound,
It is obtained by reacting an epoxy compound such as a cresol novolac type epoxy compound or an aliphatic epoxy compound with acrylic acid or methacrylic acid. When the purpose is to improve the water solubility in alkalis and the adhesion to an insulating substrate or a metal, the following method is preferred.
(1) After the reaction (reaction of an epoxy compound with acrylic acid or methacrylic acid), further oxalic acid, malonic acid, succinic acid, glutamic acid, adipic acid, maleic acid, fumaric acid, phthalic acid or terephthalic acid, Acid number 5 to 1
And a carboxylic acid compound having a carboxyl group of 00 or an anhydride thereof. Alternatively, (2) in the reaction, the epoxy group of the epoxy compound is allowed to remain by a subsequent carboxylic acid modification amount, and then oxalic acid, malonic acid, succinic acid, glutamic acid, adipic acid, maleic acid, fumaric acid, phthalic acid. It may be reacted with an acid or a dicarboxylic acid such as terephthalic acid or its anhydride. At this time, if the oxidation number is small, the alkali water solubility is poor, and if it is too large, it becomes a factor that deteriorates the properties as a resist such as chemical resistance at the time of curing and electrical properties.

(D) Examples of the diluent comprising a photopolymerizable and thermoreactive monomer include acrylate or methacrylate compounds having at least one hydroxyl group in one molecule. For example, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, butanediol monoacrylate glycerol methacrylate, phenoxy hydroxypropyl acrylate, polyethylene glycol acrylate, polyethylene glycol methacrylate, or glycerol dimethacrylate. Etc. Alternatively, a photopolymerizable monomer such as glycidyl acrylate or glycidyl methacrylate having a glycidyl group is used. Preferred monomers are glycidyl acrylate and glycidyl methacrylate, which can react with carboxylic acid and phenolic hydroxyl group for chemical resistance after thermosetting. Usually, the amount of the diluent as the component (d) is preferably 1 to 5 times the equivalent of the residual phenolic hydroxyl group or carboxylic acid group after the thermosetting reaction of the epoxy resin as the component (a).

(E) As the photopolymerization initiator, benzophenone, benzoylbenzoic acid, 4-phenylbenzophenone, benzophenones such as hydroxybenzophenone, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether,
Benzoin alkyl ethers such as benzoin isobutyl ether, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t
-Butyl-trichloroacetophenone, acetophenones such as diethoxyacetophenone, thioxanthone,
2-chlorothioxanthone, 2-methylthioxanthone,
Examples thereof include thioxanthones such as 2,4-dimethylthioxanthone and alkylanthraquinones such as ethylanthraquinone and butylanthraquinone. These may be used alone or as a mixture of two or more kinds. The addition amount of this photopolymerization initiator is usually 0.1 to
Used in the range of 10% by weight.

In addition, an ultraviolet ray inhibitor, a thermal polymerization inhibitor, a plasticizer, etc. may be added to the permanent resist of the present invention, if necessary, for storage stability. Further, an acrylate monomer, a methacrylate monomer, a vinyl monomer or the like may be added to adjust the viscosity.

The permanent resist resin composition of the present invention comprising these components has high resolution and excellent developability with an aqueous alkaline solution. In particular, regarding the solubility in an alkaline aqueous solution, the phenolic hydroxyl group of the alkylphenol novolac photothermosetting agent having at least one acryloyl group or methacryloyl group of the component (b) and the epoxy acrylate or epoxy methacrylate compound of the component (c) Is due to the carboxylic acid group of the water-soluble functional group contained in. And as described above, the photo-cured product having these functional groups remaining is a resist having poor alkali resistance, chemical resistance, electrical properties, etc., but the permanent resist resin composition of the present invention is photo-cured and after development. Is a resin composition mainly composed of a thermosetting reaction, and after the post-heat treatment, the epoxy resin of the component (a) and the glycidyl group of the component (d) are converted into the phenolic hydroxyl group of the component (b) and the glycidyl group of the component (c). It undergoes thermosetting reaction with carboxylic acid groups to form a main skeleton with excellent required properties. Therefore, it becomes a permanent resist cured product that can withstand electroless plating performed for a long time under high temperature and highly alkaline conditions.

The permanent resist resin composition according to the present invention comprises
It is applied to the adhesive for full additive in a thickness of 20 to 60 μm, and is subjected to heat treatment at 60 to 100 ° C. for about 5 to 10 minutes to be solvent-removed and solidified or prepolymerized to form a resist layer. Alternatively, a film-like material which is previously applied onto a carrier film and prepolymerized under the same conditions as above may be laminated on the adhesive layer.

[0016]

EXAMPLES The present invention will be described below based on examples. (Synthesis Example 1) Synthesis of a methacryloyl group-containing alkylphenol novolac-type photothermal curing agent 1080 g (10 mol) of cresol, formalin (37
%) 1220 g (15 mol) and oxalic acid 10 g were charged in a pressure reaction vessel and reacted at 120 ° C. (pressure 2.5 kg / cm ² ) for 4 hours. After completion of the reaction, dehydration was performed under reduced pressure and the resin temperature was 1%.
Heated to 40 ° C. After cooling, the mixture was pulverized, and the resin content was adjusted to 60% with a methyl ethyl ketone solvent to obtain an alkylphenol novolak. 800 g (about 4 equivalents of OH) of the above alkylphenol novolac was placed in a 2 l flask, 1 g of tributylamine and 0.2 g of hydroquinone were added, and the mixture was heated to 110 ° C. After 284 g (2 mol) of glycidyl methacrylate was dropped therein, the mixture was stirred and reacted at 110 ° C. for 5 hours.

(Synthesis Example 2) Synthesis of carboxyl group-containing epoxy acrylate Bisphenol A type epoxy resin
After adding 760 g (4 equivalents) of Epicoat 828 (made by Yuka Shell Epoxy: epoxy equivalent 190) and 1 g of methoxyphenol as a polymerization inhibitor, acrylic acid 288 g
(4 mol), 1 g of benzyldimethylamine was added to give 10
The mixture was reacted at 0 ° C. for 6 hours with stirring. Then succinic anhydride 1
60 g (1.6 mol) was added, and the mixture was reacted with stirring at 80 ° C. for 3 hours.

Synthesis Example 3 Synthesis of Carboxyl Group-Containing Epoxy Acrylate In a 2 l flask, 760 g (4 equivalents) of Epicoat 828 and 1 g of methoxyphenol and 1 g of benzyldimethylamine as polymerization inhibitors were added and heated to 100 ° C. Then, 180 g (2.5 mol) of acrylic acid was added dropwise over 1 hour, and the mixture was reacted with stirring at 100 ° C. for 6 hours. Then, 234 g (1.6 mol) of adipic acid was added, and the mixture was stirred and reacted for 2 hours.

Example 1 20 g of Epicoat 828,
50 g of a methacryloyl group-containing alkylphenol novolak-type photothermosetting agent of Synthesis Example 1, 15 g of a carboxyl group-containing epoxy acrylate of Synthesis Example 2 and 15 g of glycidyl methacrylate were mixed, and Irgacure 6 was used as a photoinitiator.
3 g of 51 (manufactured by Ciba Geigy) and 0.2 g of triphenylphosphine as a thermosetting accelerator were added to obtain a permanent resist resin composition.

Example 2 20 g of Epicoat 828,
50 g of a methacryloyl group-containing alkylphenol novolac-type photothermosetting agent of Synthesis Example 1, 15 g of a carboxyl group-containing epoxy acrylate of Synthesis Example 3 and 15 g of glycidyl methacrylate were mixed, and Irgacure 6 was used as a photoinitiator.
513 g and triphenylphosphine 0.2 g as a thermosetting accelerator were added to obtain a permanent resist resin composition.

Example 3 20 g of Epicoat 828,
50 g of a methacryloyl group-containing alkylphenol novolac-type photothermal curing agent of Synthesis Example 1, epoxy acrylate V
-5510 (manufactured by Dainippon Ink and Chemicals, Inc.) and 15 g of glycidyl methacrylate were mixed, and 3 g of Irgacure 651 as a photoinitiator and 0.2 g of triphenylphosphine as a heat curing accelerator were added to obtain a permanent resist. It was a resin composition.

Example 4 15 g of Epicoat 828,
Methacryloyl group-containing alkylphenol novolac-type photothermographic agent of Synthesis Example 1 (50 g), epoxy acrylate
V-5510 15g and glycidyl methacrylate 15g
Was mixed and 6513 g of Irgacure as a photoinitiator and 0.2 g of triphenylphosphine as a thermosetting accelerator were added to obtain a permanent resist resin composition.

Example 5 20 g of Epicoat 828,
50 g of a methacryloyl group-containing alkylphenol novolac type photothermosetting agent of Synthesis Example 1, epoxy acrylate S
15 g of P-4010 (manufactured by Sankyo Kasei Co., Ltd.) and 15 g of glycidyl methacrylate were mixed, and 3 g of Irgacure 651 as a photoinitiator and 0.2 g of triphenylphosphine as a thermal curing accelerator were added to obtain a permanent resist. It was a resin composition.

Example 6 10 g of Epicoat 828,
50 g of a methacryloyl group-containing alkylphenol novolac type photothermosetting agent of Synthesis Example 1, epoxy acrylate S
10 g of P-4010 and 15 g of glycidyl methacrylate were mixed, and 6513 g of Irgacure as a photoinitiator and 0.2 g of triphenylphosphine as a thermosetting accelerator were added to obtain a permanent resist resin composition.

Comparative Example 1 Epoxy acrylate SP
-4010 50 g and glycidyl methacrylate 15 g were mixed, and Irgacure 651 3 g was added as a photoinitiator to obtain a resist resin composition.

Comparative Example 2 Epoxy acrylate V-
5510 50 g and glycidyl methacrylate 15 g were mixed, and Irgacure 651 3 g was added as a photoinitiator to obtain a resist resin composition.

[Preparation of Additive Process Multilayer Printed Wiring Board] The resin compositions obtained in Examples 1 to 9 and Comparative Example were placed on a catalyst-activated adhesive-bonded laminate with catalyst activation treatment.
It was applied to a thickness of 0 μm and heat-treated at 100 ° C. for 10 minutes. However, in the comparative example, since the liquid was tacky even after the heat treatment, the cover film was brought into contact with the resist. A predetermined pattern was placed on this laminated plate and exposed with a high-pressure mercury lamp exposure device at an irradiation dose of 300 mJ / cm ² . Then, with an aqueous solution of sodium hydroxide, 2 Kg / m
Developed with a spray pressure of ² . After washing and drying, 1 J /
Cm ² was post-exposed and heat-treated at 150 ° C. for 30 minutes. This was immersed in an electroless copper plating solution at 70 ° C. for 10 hours to form an electroless copper plating film of about 20 μm, and an additive method multilayer printed wiring board was produced.

Table 1 shows the results of evaluation of resist characteristics in the process of obtaining the additive-type multilayer printed wiring board in this manner. Table 1 ──────────────────────────── Developability Solvent resistance Plating liquid resistance Solder heat resistance ──────── ──────────────────── Example 1 ○ ○ ○ ○ Example 2 ○ ○ ○ ○ Example 3 △ ○ ○ ○ Example 4 ○ ○ △ △ Example 5 △ ○ ○ ○ Example 6 ○ ○ ○ ○ ───────────────────────────── Comparative Example 1 × Peeling × × Comparative Example 2 × △ △ ○ ─────────────────────────────

(Measurement method) 1. Developability ◯: Development is possible, Δ: There is some development residue, X: Development residue 2. Solvent resistance: No change was observed after 20 minutes of immersion in acetone. 3. Resistance to plating solution: No change was observed in the electroless copper plating process. 4. Solder heat resistance n = 5, 260 ° C for all test pieces,
The case where no change was observed after 20 seconds was marked with “◯”.

[0030]

As described above, the permanent resist resin composition for a printed wiring board of the present invention and the cured product thereof have high resolution and are easy to develop with an aqueous alkaline solution, but they are isopropyl alcohol and trichloroethylene. Resistance to methylene chloride, acetone, etc.,
We also manufacture printed wiring boards with excellent resistance to electroless plating that is performed under high temperature and high alkaline conditions for a long time, as well as heat resistance that can withstand temperatures around 260 ° C during the soldering process. Made possible

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H05K 3/18 H05K 3/18 D 3/28 3/28 D

Claims (5)

(57) [Claims] 1. The following components (a), (b), (c),
A resin composition comprising (d) and (e). (A) Polyfunctional epoxy resin having an epoxy equivalent of 120 to 500, (b) obtained by reacting an alkylphenol novolac and an acrylate or methacrylate having a glycidyl group, and one or more acryloyl group or methacryloyl group and one in one molecule. Alkylphenol novolac type photothermosetting agent having the above phenolic hydroxyl group, (c) epoxy acrylate or epoxy methacrylate compound having a carboxyl group having an acid value of 5 to 100 , (d) photopolymerization and thermoreactive monomer (E) A photopolymerization initiator. 2. A permanent resist resin composition for a printed wiring board, which comprises using the resin composition according to claim 1 in a printed wiring board. 3. The permanent resist resin composition for a printed wiring board according to claim 2, wherein the component (a) is a liquid bisphenol A type epoxy resin or a liquid bisphenol F type epoxy resin. 4. A component according to claim 2 or 3 (d) is a diluent consisting of photopolymerization and thermal reactive monomer having one or more acryloyl groups or methacryloyl groups and one or more glycidyl groups in one molecule The permanent resist resin composition for printed wiring boards according to. 5. A cured product of the resin composition according to claim 1 .