JPH0694493B2 - Photosensitive polymerization composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a photosensitive polymer composition which is cured by irradiation with light and can be developed with an alkaline aqueous solution. More specifically, it relates to a photosensitive polymer composition having improved resistance to etching, plating and the like after development.

(Prior art and problems) Generally, a photopolymerization cured product is applied to a substrate, for example, a copper clad laminate, a metal surface to be subjected to microfabrication, or the like, is laminated by lamination, and exposed to active light to cure an exposed portion,
The unexposed area is dissolved and removed by a solvent having an appropriate solubility. The solvent is roughly classified into one using an organic solvent such as 1,1,1-trichloroethane and one using an aqueous solvent such as an aqueous sodium carbonate solution.

BACKGROUND ART In recent years, photosensitive polymerization compositions that are developed using an aqueous solvent have been gradually used in terms of work environment, surrounding environment, and manufacturing cost.

However, as compared with the case of using a conventional organic solvent developing type photopolymerization / curing composition, there are many restrictions on the treatment of etching and plating, and this often causes a problem in use.

Particularly in the case of an alkaline processing liquid, the use is basically limited because an acidic thermoplastic polymer binder is basically used.

However, on the contrary, when a thermoplastic polymer binder that can withstand these alkaline treatment liquids is used, it takes a long time or is completely non-existent when the cured film is finally peeled off with the alkaline liquid. It was possible.

(Means for Solving Problems) As a result of intensive studies made by the present inventors in order to solve such a problem, as a result, an addition polymerizable compound obtained by copolymerizing an addition polymerization monomer having a specific structure It has been found that both resistance and releasability can be satisfied by combining a thermoplastic polymer binder of the type with an addition polymerizable compound having a specific structure, and the present invention has been reached.

That is, the present invention includes (1) an addition-polymerized monomer (A) having a carboxyl group as a main component.
Thermoplastic polymer binder obtained by copolymerizing 4 to 40% by weight of the following non-acidic addition-polymerized monomer (B) with at least 5% by weight and the following non-acidic addition-polymerized monomer (C) .

Non-acidic addition-polymerized monomer (B): at least one of acrylic acid ester or methacrylic acid ester monomer represented by the following general formula (I) (R ₁ is a hydrogen atom or a methyl group, R ₂ is an alkylene group having 1 to 5 carbon atoms, R ₃ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom, and n is an integer of 1 to 20. ) Non-acidic addition-polymerizable monomer (C): at least one non-acidic addition-polymerizable monomer having a Q value and an e-value satisfying the following formula (II) (Q _A and e _A are the Q and e values of the addition-polymerized monomer (A), Q _C and e _C
Is the Q value and e value of the addition-polymerizable monomer (C)) (2) At least an addition-polymerizable compound represented by the following formula (III) (R ₄ , R ₅ , R ₆ , R ₉ , R ₁₀ , and R ₁₁ are hydrogen atoms or methyl groups,
R ₇ and R ₈ are hydrogen atoms, halogen atoms n and m are n + m = 2
It is a positive integer such that -20.) (3) A photosensitive polymerization composition comprising at least one photoinitiator.

First, the thermoplastic polymer binder used in the present invention will be described in detail. In the photopolymerizable cured composition of the addition polymerizable compound type according to the present invention, the resistance of the resist film is largely dependent on the properties of the polymer binder. The acidic addition-polymerizable monomer (A) having a carboxyl group in the copolymer forming the polymer binder of the present invention imparts developability to the copolymer, and its proportion in the copolymer composition As 4
In the range of up to 40 weight percent. The appropriate ratio varies depending on the kind of the developing solution. For example, it is 4 to 15% by weight in a so-called semi-aqueous solution developing type containing ethylene glycol monobutyl ether and the like and 15 in a complete aqueous solution developing type.
The range of up to 40% by weight can be used as a rough guide. Of course, the optimum copolymerization rate of the acid addition polymerization monomer of the semi-aqueous solution type or the complete aqueous solution type varies depending on the developing solution and the developing conditions. In the present invention, the addition polymerization monomer (A) having a carboxyl group is preferably methacrylic acid or a mixture of methacrylic acid and acrylic acid.

Since the acidic addition-polymerized monomer is copolymerized, the thermoplastic polymer binder essentially swells and dissolves in an alkaline liquid. Therefore, it is essential to copolymerize a non-acidic addition monomer in order to impart resistance. Particularly, a non-acidic addition-polymerizable monomer (B) which is an acrylic acid ester or a methacrylic acid ester having a specific structure is effective for improving the resistance to an alkaline aqueous solution.

Examples of such compounds include 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, 2-phenoxypropyl acrylate, 3-phenoxypropyl acrylate, phenoxydiethoxy acrylate, phenoxytriethoxy acrylate, and phenoxyacrylate. Dipropoxy, P-chlorphenoxyethyl acrylate, P-methylphenoxyethyl acrylate, methacrylate 2
-Phenoxypropyl, methacrylic acid, 3-phenoxypropyl, phenoxydiethoxy methacrylate, phenoxytriethoxy methacrylate, phenoxydipropoxy methacrylate, P-chlorophenoxyethyl methacrylate, P-methylphenoxyethyl methacrylate and the like. However, the invention is not limited to these. These non-acidic addition-polymerizable monomers (B) must be contained in the copolymer in an amount of at least 5 weight percent or more.

The non-acidic addition-polymerized monomer (C) is the addition-polymerized monomer (B)
It also serves as a component that imparts resistance, but additionally has a role of controlling the glass transition point (Tg) of the copolymer. A suitable copolymer Tg is between 40 ° C. and 120 ° C., and at 40 ° C. or lower, when the photosensitive layer is sandwiched between the support film and the protective film, the photosensitive layer flows out with time when used as a “dry film”. "Cold flow" phenomenon occurs,
On the other hand, when the temperature is 120 ° C. or higher, the adhesion of the photosensitive layer to the substrate is significantly impaired.

Furthermore, the non-acidic addition-polymerizable monomer (C) has a function of forming a copolymer in which the acidic addition-polymerizable monomer (A) is uniformly and intramolecularly polymerized. If the acidic addition-polymerized monomers are not uniformly polymerized, not only will the development of the cured composition be poor, but in the worst case, precipitation of the copolymer during polymerization and precipitation of the copolymer during blending with the coating liquid will occur. Occurs. Such a non-acidic addition-polymerized monomer (C) is determined according to the acidic addition-polymerized monomer (A). For example, as the polymerized monomer (A), methacrylic acid (Q _A = 2.340, e _A = 0.65)
When selecting 0), methyl methacrylate (Q _C = 0.740,
e _C = 0.400, Ethyl methacrylate (Q _C = 0.730, e _C = 0.520, And so on. In this case, n-butyl acrylate (Q _C = 0.500, e _C = 1.060, Then, methacrylic acid is rapidly consumed during the polymerization, resulting in a non-uniform copolymer composition, and in some cases precipitation occurs.

When a plurality of acidic addition-polymerized monomers (A) are used in the present invention, the non-acidic addition-polymerized monomer (C) is at least one acidic addition-polymerized monomer (A) among them. It satisfies the above formula (II).

Examples of the addition-polymerizable compound represented by the formula (III) include 2,2 bis (4-acryloxygetoxyphenyl) propane,
2-bis (4-acryloxypentaethoxyphenyl)
Propane, 2,2-bis (4-methacryloxygetoxyphenyl) propane, 2,2-bis (4-methacryloxypentaethoxyphenyl) propane, 2,2-bis (4-acryloxydipropoxyphenyl) propane, 2,2-bis (4-acryloxypentapropoxyphenyl) propane, 2,2-bis (4-methacryloxydipropoxyphenyl) propane, 2,2-bis (4-methacryloxypentapropoxyphenyl) propane, etc. However, the present invention is not limited to these. These may be used alone or as a mixture of two or more. These are 5 to 100 parts by weight per 100 parts by weight of the thermoplastic polymer binder, particularly preferably 10 to 10 parts by weight.
Use 80 parts by weight. It is also possible to add other addition-polymerizable compounds as needed.

The photoinitiators that can be used in the composition of the present invention include the following.

That is, there are substituted or unsubstituted polynuclear quinones, for example, 2
-Ethyl anthraquinone, 2-tert-butyl anthraquinone, octamethyl anthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone,
1-chloroanthraquinone, 2-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthaquinone,
9,10-phenanthraquinone, 2-methyl-1,4-naphthaquinone, 2,3-dichloronaphthaquinone, 1,4-dimethylanthraquinone, 2,3-dimethylanthraquinone, 3-chloro-2-methylanthraquinone, Examples include 7,8,9,10-tetrahydrophthalcenequinone. Other aromatic ketones such as benzophenone, Michler's ketone [4,4 '
-Bis (dimethylamino) benzophenone], 4,4'-
Bis (diethylamino) benzophenone], 4-methoxy-4′-dimethylaminobenzophenone and the like.
Other examples include benzoin and benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether, methylbenzoin and ethylbenzoin. Further, a combination of 2,4,5-triarylimidazole dimer with 2-mercaptobenzoxazole, leuco crystal violet, tris (4-diethylamino-2-methylphenyl) methane and the like can also be used.

In addition, there are substituted or unsubstituted thioxanthones, such as 2-chlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-dimethylthioxanthone. Further, a combination of these thioxanthones with an aliphatic or aromatic tertiary amine such as N-methyldiethanolamine, P-dimethylaminobenzoic acid ethyl ester and the like can also be used, and thioxanthones and alkylaminobenzophenes such as Michler's ketone can be used. Or a combination of thioxanthones and an oxime ester such as benzophenone oxime acetate. These addition-polymerizable initiators that can be activated by light may be used alone or in combination of two or more. The present invention is not limited to these.

These are 0.01 per 100 parts by weight of the thermoplastic polymer binder.
-30 parts by weight, preferably 0.1-15 parts by weight.

In the present invention, in addition to the above essential elements, stabilizers, dyes and the like can be added if necessary. Examples of the stabilizer include hydroquinone, hydroquinone monomethyl ether, t-butylcatechol and the like. These can be added within a range that does not inhibit the photopolymerization reaction. Also, a plasticizer for imparting appropriate flexibility can be added. For example, phthalic acid esters such as diethyl phthalate, dibutyl phthalate, diheptyl phthalate and dioctyl phthalate, fatty acid esters such as dioctyl adipate and dibutyl diglycol adipate, phosphoric acid esters such as trimethylphosphine, sulfone such as triene sulfonic acid amide. Examples thereof include acid amides.

Further, a dye may be added to facilitate the visual discrimination of the photosensitive layer. Examples thereof include crystal violet, malachite green, Victoria blue, methylene blue and the like.

In the present invention, when the photopolymerization curable composition is solvent-free, it is usually coated by a printing method or a coating method, and when it is dissolved or dispersed in a solvent, it is coated on a suitable support, and then the solvent is added. A photopolymer layer can be obtained by evaporation. In particular, when used as a "dry film", various plastic films, of which polyester film is preferable.

(Effects of the Invention) According to the present invention, a photo-cured film that is easier to peel with an alkaline liquid than in the past can be obtained. Details will be described with reference to examples.

Such a photopolymer layer is cured by light from a suitable light source such as a low pressure mercury lamp or an ultrahigh pressure mercury lamp. The composition of the present invention can be used as a photopolymer or a photoresist when producing a metal relief image or a printed wiring board.

(Examples) Next, the present invention will be specifically described with reference to Examples. The present invention is not limited to the embodiment.

Example 1 The following components were mixed to obtain a photosensitive polymerization composition.

Methacrylic acid 12 wt%, acrylic acid 8 wt%, methyl methacrylate 45 wt%, 2-phenoxyethyl acrylate 35 wt%
Copolymer of 50g 2,2 Bis (4-acryloxygetoxyphenyl) propane 30g 2-Chlorthioxanthone 1g N-Methyldiethanolamine 0.1g Victoria blue 0.05g Methyl ethyl ketone 70g Tetrahydrofuran 10g It was applied on the body and dried at 75 ° C to obtain a photosensitive film. The thickness of the photosensitive layer was 50 μm. This was laminated on a polished copper clad laminate with a rubber roller heated to 100 ° C. Place a wiring circuit pattern mask on it and irradiate it from a distance of 50 cm with a 2 kW ultra-high pressure mercury lamp for 10 seconds to cure it, and then develop with a 1% sodium carbonate aqueous solution at 30 ° C. to obtain a resin relief image on the copper clad laminate. Was given.

Next, this was subjected to copper etching with an alkaline etchant to obtain a good printed wiring board.

Next, the cured film was immersed in a 3% aqueous sodium hydroxide solution at 50 ° C. to peel it off completely in about 1 minute 30 seconds.

Example 2 The following components were mixed to obtain a photosensitive polymerization composition.

Methacrylic acid 12 wt%, acrylic acid 8 wt%, methyl methacrylate 45 wt%, 2-phenoxyethyl acrylate 35 wt%
Copolymer of 50g Trimethylolpropane acrylate 15g 2,2 Bis (4-acryloxydiethoxyphenyl) propane 15g 2-Chlorthioxanthone 1g N-Ethyldiethanolamine 0.1g Victoria blue 0.05g Methylethylketone 70g Tetrahydrofuran 10g It was coated on a polyethylene glycol terephthalate film support and dried at 75 ° C. to obtain a photosensitive film. The thickness of the photosensitive layer was 50 μm. This was laminated on a polished copper clad laminate with a rubber roller heated to 100 ° C. After placing a wiring circuit pattern mask on it and irradiating it from a distance of 50 cm with a 2 KW ultra-high pressure mercury lamp for 10 seconds to cure it, develop it with a 1% sodium carbonate aqueous solution at 30 ° C. to obtain a resin relief image on the copper clad laminate. Was obtained.

Next, copper was etched with an alkaline etchant to obtain a good printed wiring board.

Next, in order to peel off the cured film, it was immersed in a 3% aqueous sodium hydroxide solution at 50 ° C., and it was completely peeled off in about 2 minutes.

Example 3 The following components were mixed to obtain a photosensitive polymerization composition.

Methacrylic acid 10wt%, acrylic acid 10wt%, methyl methacrylate 50wt%, 2-phenoxyethyl acrylate 30wt%
Copolymer of 50g Trimethylolpropane triacrylate 15g 2,2 Bis (4-methacrylocypentaethoxyphenyl)
Propane 15 g Benzophenone 1.5 g Michler's Ketone 0.15 g Victoria Blue 0.05 g Methyl ethyl ketone 70 g Tetrahydrofuran 10 g Evaluation was made in the same manner as in Example 1, but a good printed wiring board was obtained and the cured film was completely peeled off in about 2 minutes.

Comparative Example 1 The following components were mixed to obtain a photosensitive polymerization composition.

Copolymer of acrylic acid 20 wt% and methyl methacrylate 80 wt% 50 g trimethylolpropane triacrylate 15 g 2,2 bis (4-acryloxydiethoxyphenyl) propane 15 g 2-chlorothioxanthone 1 g N-methyldiethanolamine 0.1 g Victoria blue 0.05 g Methyl ethyl ketone 70 g Tetrahydrofuran 10 g Evaluation was made in the same manner as in Example 1, but the cured film could not withstand an alkaline etchant and a good printed wiring board could not be obtained.

Comparative Example 2 The following components were mixed to obtain a photosensitive polymerization composition.

Methacrylic acid 12 wt%, acrylic acid 8 wt%, methyl methacrylate 45 wt%, 2-phenoxyethyl acrylate 35 wt%
50 g trimethylolpropane triacrylate 30 g 2-chlorothioxanthone 1 g N-methyldiethanolamine 0.1 g Victoria blue 0.05 g Methyl ethyl ketone 70 g Tetrahydrofuran 10 g Evaluation was carried out in the same manner as in Example 1. Although it withstood the alkaline etchant, it took about 4 minutes to peel off the cured film.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C08F 265/02 MQM 7308-4J

Claims (3)

[Claims] 1. A main component (1) 4 to 40% by weight of an addition polymerization monomer (A) having a carboxyl group and at least 5% by weight or more of the following non-acidic addition polymerization monomer (B): A thermoplastic polymer binder obtained by copolymerizing a non-acidic addition-polymerized monomer (C). Non-acidic addition-polymerized monomer (B): at least one of acrylic acid ester or methacrylic acid ester monomer represented by the following general formula (I) (R ₁ is a hydrogen atom or a methyl group, R ₂ is an alkylene group having 1 to 5 carbon atoms, R ₃ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom, and n is an integer of 1 to 20. ) Non-acidic addition-polymerizable monomer (C): at least one non-acidic addition-polymerizable monomer having a Q value and an e-value satisfying the following formula (II) (Q _A and e _A are Q values and e values of the addition polymerization monomer (A), and Q _C and e _C are Q values and e values of the addition polymerization monomer (C)) (2) At least the following formula (III ) Addition-polymerizable compound (R ₄ , R ₅ , R ₆ , R ₉ , R ₁₀ , and R ₁₁ are hydrogen atoms or methyl groups,
R ₇ and R ₈ are hydrogen atoms, halogen atoms, and n and m are n + m =
A positive integer such as 2 to 20) (3) A photosensitive polymerization composition comprising at least one photoinitiator. 2. A thermoplastic polymer binder as a main component 100 parts by weight, an addition polymerizable compound 10 to 200 parts by weight, and a photoinitiator 0.01.
The photopolymerizable composition according to claim 1, which comprises -30 parts by weight. 3. The photosensitive polymerization composition according to claim 2, wherein the addition-polymerizable monomer (A) having a carboxyl group is methacrylic acid alone or a mixture of methacrylic acid and acrylic acid.