JP2527271B2 - Negative photosensitive electrodeposition coating resin composition and electrodeposition coating bath using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a negative photosensitive electrodeposition coating resin composition and an electrodeposition coating bath using the same.

[Conventional technology]

When manufacturing a printed circuit board, first, a layer of a photocurable resin composition is formed on a substrate, and then an actinic ray is imagewise irradiated to develop and remove an uncured portion to form a resist pattern. . In this step, various methods are adopted for forming the layer of the photocurable resin composition.
For example, a method using a photocurable resin composition solution (coating liquid) such as a day coat, roll coat, or curtain coat, or a method of laminating a film (photosensitive film) of the photocurable resin composition is known. Among these methods, the method of laminating a photosensitive film is currently adopted as the mainstream method because a layer of a photocurable resin composition having a uniform thickness can be easily formed.

[Problems to be Solved by the Invention]

Recently, as the density and precision of printed circuit boards have increased, higher quality resist patterns have been required. That is, it is desired that the resist pattern has no pinhole and is more closely attached to the surface of the underlying substrate. It is known that the method of laminating photosensitive films, which is the mainstream at present, has a limit to meet such demand. This method follows the unevenness of the substrate surface caused by dents during manufacturing of the substrate, non-uniformity of polishing, mesh of glass cloth on the inner layer of the substrate, non-uniformity of pits with copper plating on the surface, etc. Is poor and it is difficult to obtain sufficient adhesion. This difficulty can be avoided by stacking the films under reduced pressure (see Japanese Patent Publication No. 59-3740).
This requires special and expensive equipment.

For this reason, solution coating methods such as deep coating, roll coating, and curtain coating have come to be reviewed again in recent years. However, these coating methods have problems that it is difficult to control the film thickness, the film thickness is not uniform, and pinholes occur.

Therefore, as a new method, a method of forming a photosensitive film by electrodeposition coating has recently been proposed (see JP-A-62-235496). According to this method, the adhesiveness of the resist is improved, the conformability to irregularities on the substrate surface is excellent, a photosensitive film having a uniform film thickness can be formed in a short time, and the coating solution is an aqueous solution, so that the working environment is contaminated. It has the advantage that it can be prevented and there is no problem in disaster prevention. Therefore, some proposals have recently been made regarding the composition of the electrodeposition bath suitable for this.

For example, a composition containing a polymer having an unsaturated bond as a main component has been proposed (see Japanese Patent Application Laid-Open No. 62-262855), which has high photosensitivity but is difficult to synthesize.
Further, there is a problem that the composition is easily cross-linked during storage and the stability of the electrodeposition bath is low.

Further, the composition in which a polymer is mixed with an ethylenically unsaturated compound (see JP-A-61-247090 and JP-A-62-235496) has a high sensitivity and easily suppresses a crosslinking reaction during storage, so that a negative type Although it is a good composition as a photoresist material, unlike the composition having a polymer introduced with an unsaturated bond as the main component, it becomes at least a two-component system containing an ethylenically unsaturated compound, and therefore, that amount However, it is necessary to devise to improve the water dispersibility and the electrodeposition coating property. Considering the photosensitivity of the electrodeposition coating film (photosensitive film) as well as the subsequent developability and etching resistance, The most important technical issue was the optimization of the polymer composition. Generally, in this case, as the polymer, a (meth) acrylic polymer is used because it is easy to synthesize and the raw material can be obtained at low cost. However, the copolymerization composition of various monomers constituting the polymer is as described above. Since it is greatly related to each property, how to use an appropriate amount of copolymerizable monomer is an important point of development.

On the other hand, as a conventional problem of the method of forming a photosensitive film by electrodeposition coating, since the photosensitive film has high adhesiveness, it is easily scratched and sticks when the photosensitive films are stacked. As a countermeasure against this, there has been proposed a method of providing a harder protective film on the surface of a photosensitive film obtained by electrodeposition coating [Method of forming protective film by coating (JP-A-63-60
No. 594), and a method of forming a protective film by electrodeposition coating (see JP-A-2-20873)].

These methods require additional steps, and
If the conditions for providing the protective film are not strictly controlled, there are various problems such as deterioration in sensitivity and resolution during subsequent exposure, and this measure is not necessarily a good measure. After all, it is desirable to provide a hard photosensitive film that is hard to be scratched by one electrodeposition coating and has no adhesion between the photosensitive films.

[Means for solving the problem]

Therefore, there is no problem in terms of stability of the above-mentioned synthesis and electrodeposition coating bath, and as a result of the inventors' diligent examination of a system in which a water-insoluble monomer is mixed with a polymer that is a good resist material, the results show that Glass transition point 65-120 ℃
It was found that a photosensitive film satisfying the above object can be obtained by the above. However, it has been found that when a polymer having such a high glass transition point is used, only a thin film having a thickness of several μm can be obtained under ordinary electrodeposition conditions, and the film may have a poor appearance such as smoothness.

Therefore, as a result of further studies to improve the electrodeposition property, when 60 to 85 parts by weight of methyl methacrylate was used as a copolymerization monomer constituting a polymer other than acrylic acid and / or methacrylic acid, the electrodeposition property was It is easy to obtain a thick film with a good appearance and a good coating appearance, and because the mechanical strength of the photosensitive film is high, scratches are less likely to occur compared to the photosensitive film obtained by conventional electrodeposition coating, and the photosensitive films are It was found that even if they are stacked, they can be stacked without sticking.

Further, the glass transition point of the polymer according to the present invention is 75 to 12
It was also found that by setting the temperature to 0 ° C., the resist shape becomes more rectangular than in the conventional case and a pattern with a narrow line width can be sufficiently resolved. Further, it is preferable to add a film forming agent having 1 to 2 hydroxyl groups in the molecule to the electrodeposition bath,
The electrodeposition properties such as appearance and film thickness can be improved.

That is, the present invention provides (a) an acid value of 20 to 300 obtained by copolymerizing a polymerizable monomer containing acrylic acid and / or methacrylic acid, and a glass transition point of 7
A polymer obtained by neutralizing a polymer at 5 to 120 ° C. with a basic organic compound, (b) a water-insoluble monomer having two or more photopolymerizable unsaturated bonds in the molecule, and (c) a water-insoluble photoinitiator. Negative-type photosensitive electrodeposition coating resin composition containing the same, an electrodeposition coating bath using the same, and a conductive substrate as an anode immersed in the electrodeposition coating bath, and electrodeposition coating by energization Then, an electrodeposition coating film is formed on the electrodeposited film, and then an actinic ray is imagewise irradiated to the electrodeposition coating film to photo-cure the exposed part and remove the unexposed part by development to form a photo-cured resist pattern. The present invention relates to a method for manufacturing a resist pattern.

 The present invention will be described in detail below.

The polymer as the component (a) has an acid value of 20 to 300 obtained by copolymerizing acrylic acid and / or methacrylic acid as an essential component.
It is a polymer obtained by neutralizing a polymer having a glass transition point of 75 to 120 ° C with a basic organic compound. Acrylic acid and methacrylic acid can be used alone or in combination of both, and the amount used is appropriately selected so that the acid value of the polymer is in the range of 20 to 300. When the acid value of the polymer is less than 20, the water dispersion stability is poor when a basic organic compound is added to the photosensitive electrodeposition coating resin composition and then water is added to disperse the composition, and the composition tends to settle. Also, the acid value of the polymer is 30
When it exceeds 0, the appearance of the electrodeposition film is inferior.

The polymer before neutralization includes, for example, methyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n, in addition to acrylic acid and / or methacrylic acid.
-Hexyl acrylate, n-octyl acrylate, n-
It can be obtained by copolymerizing one or more kinds of general polymerizable monomers such as octyl methacrylate, n-decyl methacrylate, cyclohexyl methacrylate, 2-hydroxyethyl acrylate, cyclohexyl methacrylate, acrylonitrile, styrene and vinyl chloride. These general polymerizable monomers are appropriately selected so that the glass transition point, which is one of the features of the present invention, is in the range of 75 to 120 ° C.,
You can decide the usage ratio of them. The glass transition point of the polymer before neutralization referred to in the present invention is proposed by Fox [TG Fox, Jr, Bull. Am. Phys. Soc., 1 , 123.
(1956)] It is a value calculated based on the following formula.

Tg: glass transition temperature of copolymer W ₁ , W ₂ … W _n : weight fraction of each monomer constituting the copolymer Tg ₁ , Tg ₂ … Tg _n : glass transition of homopolymer of each monomer In the case of acrylic acid, the glass transition point of the homopolymer of each monomer used in the calculation of the formula is 130 ° C [A. Odaji
ma, AEWoodward, JASauer, J.Polym, Sci., 55,181 (196
1)], 185 ° C for methacrylic acid (HL Greenberg,
“Handbook of Water Solukle Gums and Posins" Mc Gra
w-Hill, New York, 1980, Chapter, 17, PP1-19), Herm in the case of acrylic acid esters and methacrylic acid esters
an Mark, Norbert M Bikales, Charles G Overkerger, Geo
rg Menges “ENCYCLOPEDIA OF POLYMER SCIENCE AND ENG
INEERING "SECOND EDITION, John Wiley & Sons, 1985, Vo
11. Values described in Takle 13 and 14 of PP257 to 258, for example, ethyl acrylate is -24 ° C, n-butyl acrylate is -55 ° C, methyl methacrylate is 105 ° C, n-
Butyl methacrylate is 20 ℃, and in the case of acrylonitrile, it is 85 ℃ (CRBohn, JRSchaffgen, WSStati
on, J.Polym.Sci., 55,531 (196)], in the case of styrene, 1
00 ℃ (Kyozo Kitaoka “Introduction to Synthetic Resins for Paints” PP17, Polymer Publishing Association, 1982), in the case of vinyl chloride 87 ° C (Kyozo Kitaoka, “Introduction to Synthetic Resins for Paints” PP17, Polymer Publishing Association, 1982) ).
When a monomer other than those mentioned above is copolymerized, a homopolymer of the monomer is obtained by solution polymerization (weight average molecular weight of about 40,000) described below, and the glass transition point value measured by differential scanning calorimetry (DSC). Was used.

In any case, it is important in the present invention to use a polymer before neutralization having a glass transition point in the range of 75 to 120 ° C. calculated using the above formula. Above all, 60 to 85 parts by weight of methyl methacrylate are copolymerized to 100 parts by weight of the total amount of copolymerized monomers, and the glass transition point is 75 to 120 ° C.
When the polymer before neutralization in the range of is used, both the electrodeposition property and the mechanical strength of the photosensitive film are good, and the features of the present invention can be most exerted. If the glass transition point of the polymer before neutralization is less than 75 ° C, the mechanical strength of the photosensitive film tends to be low, and if it exceeds 120 ° C, the electrodeposition property tends to be lowered.

The synthesis of the polymer before neutralization is obtained by a general solution polymerization of the above-mentioned monomer in an organic solvent using a polymerization initiator such as azobisisobutyronitrile, azobisdimethylvaleronitrile and benzoyl peroxide. The polymer as the component (a) can be obtained by neutralizing the polymer with a basic organic compound described below. In this case, considering that the organic solvent to be used is for electrodeposition coating, dioxane,
It is preferable to mainly use a hydrophilic organic solvent such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoacetate, and diethylene glycol monoethyl ether acetate. If a hydrophobic organic solvent such as toluene, xylene, or benzene is mainly used, it is necessary to distill off the solvent after the polymer synthesis and replace it with the hydrophilic solvent. The weight average molecular weight (converted to standard polystyrene) of the polymer is preferably 5,000 to 150,000. If it is less than 5,000, the mechanical strength of the resist tends to be weak, and if it exceeds 150,000, the electrocoating property tends to be poor and the appearance of the coating film tends to be poor.

The amount of the polymer used as the component (a) is preferably 50 to 85 parts by weight, more preferably 60 to 75 parts by weight, based on 100 parts by weight of the total amount of (a) and (b). preferable. If the amount used is less than 50 parts by weight, the mechanical strength of the resist tends to be weak and the toughness tends to be inferior. If the amount used exceeds 85 parts by weight, the proportion of the photopolymerizable monomer as the component (b) decreases and the optical strength is reduced. The sensitivity to is likely to decrease.

Examples of the water-insoluble monomer having two or more photopolymerizable unsaturated bonds in the molecule which is the component (b) include, for example, α, β- in polyhydric alcohols other than polyethylene glycol condensed with one or more ethylene glycol. Compounds obtained by adding unsaturated carboxylic acids, such as trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, dimethy Compounds obtained by adding α, β-unsaturated carboxylic acid to a glycidyl group-containing compound, such as pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate,
For example, trimethylolpropane triglycidyl ether triacrylate, bisphenol A glycidyl ether di (meth) acrylate, and other polycarboxylic acids such as phthalic anhydride and a substance having a hydroxyl group and an ethylenically unsaturated group, such as β-hydroxyethyl. An esterified product such as (meth) acrylate can be used, and a urethane diacrylate compound having a urethane skeleton can also be used. In any case, it is water-insoluble and can be cured by light irradiation. . In that sense, hydrophilic monomers such as (poly) ethylene glycol diacrylate are outside the scope of the present invention. These can be used alone or in combination of two or more. The amount of the component (b) used is preferably in the range of 15 to 50 parts by weight, preferably 25 to 40 parts by weight, based on 100 parts by weight of the total amount of the components (a) and (b). If the amount used is less than 15 parts by weight, the sensitivity to light tends to decrease, and if it exceeds 50 parts by weight, the resist tends to become brittle.

Examples of the water-insoluble photoinitiator or photoinitiator system as the component (c) include benzophenone, N, N'-tetramethyl-4,4'-diaminobenzophenone, and 4-methoxy-.
Aromatic ketones such as 4'-dimethylaminobenzophenone, 2-ethylanthraquinone, phenanthrenequinone,
Benzoyl ethers such as benzoyl methyl ether, benzoin ethyl ether and benzoinphenyl ether, benzoins such as methylbenzoin and ethylbenzoin, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o- Chlorophenyl) -4,5
-Di (m-methoxyphenyl) imidazole dimer, 2,
4-di (p-methoxyphenyl) -5-phenylimidazole dimer and the like can be mentioned. These can be used alone or in combination of two or more.
The amount of the component (c) used is preferably 0.1 to 15 parts by weight based on 100 parts by weight of the total amount of (a) and (b), and is 0.2.
More preferably, it is from 10 to 10 parts by weight. If the amount used is less than 0.1 parts by weight, the sensitivity to light tends to decrease.
If the amount is more than parts by weight, light absorption on the surface of the composition during exposure tends to increase, and internal photocuring tends to be insufficient.

All components (b) and (c) must be water insoluble. If it is water-soluble, it becomes difficult to perform electrodeposition coating in a state of being uniformly mixed with other components.

The photosensitive electrodeposition coating resin composition of the present invention contains a dye,
A colorant such as a pigment may be contained. As a colorant,
For example, fuchsin, auramine base, crystal violet, Victoria piurea blue, malachite green, methyl orange, acitivity oleut RRH and the like are used.

Furthermore, a thermal polymerization inhibitor, a plasticizer, an adhesion promoter, an inorganic filler, etc. may be added to the photosensitive resin composition of the present invention.

The negative electrodeposition coating resin composition is, for example, (a), (b)
And a hydrophilic organic solvent used when synthesizing a solution in which the component (c) is uniformly dissolved in the above-mentioned hydrophilic organic solvent (in this case, the polymer before neutralization (polymer precursor of the component (a)) is synthesized) May be used as it is, or another hydrophilic organic solvent may be added after the synthetic solvent is distilled off. Moreover, two or more kinds of hydrophilic organic solvents may be used. The amount of the hydrophilic organic solvent used is the solid content 10 including the components (a), (b) and (c).
It is preferably in the range of 300 parts by weight or less relative to 0 parts by weight], by adding a basic organic compound to the solution to neutralize the carboxyl groups contained in the polymer before neutralization The polymer can be adjusted by making it water-soluble or water-dispersible. The basic organic compound used here is not particularly limited, and examples thereof include triethylamine, monoethanolamine, diethanolamine, diisopropylamine, dimethylaminoethanol, and morpholine. These are used alone or in combination of two or more. be able to. The amount of these basic organic compounds used is preferably 0.2 to 1.0 equivalent relative to 1 equivalent of the carboxyl group in the polymer before neutralization. If it is less than 0.2 equivalent, the water dispersion stability of the electrodeposition coating bath tends to decrease, and if it exceeds 1.0 equivalent, the coating film thickness after electrodeposition coating tends to be thin and the appearance tends to deteriorate.

Further, basic inorganic compounds such as sodium hydroxide and potassium hydroxide are liable to be hydrolyzed in the negative photosensitive electrodeposition coating resin composition, and therefore should not be used.

In the case of using a polymer having a high glass transition point in the present invention, when the electrodeposition property is lowered, from the viewpoint of maintaining good electrodeposition property, the negative electrodeposition coating resin composition contains a hydroxyl group in the molecule. It is preferable to contain a film forming agent composed of one or two hydrophilic organic solvents. The film-forming agent used in synthesizing the polymer is a hydrophilic organic solvent contained in the electrodeposition coating bath as it is, for example, ethylene glycol,
Solvents such as monomethyl ether, propylene glycol, and monomethyl ether are also included, but an organic solvent having 1 to 2 hydroxyl groups in the molecule is used during the synthesis of the polymer, and the solvent is directly included in the electrodeposition coating bath. In that case, it is particularly preferable to use a solvent having a structure different from that of the solvent as the film-forming agent. Examples of the film-forming agent in the present invention include n-propanol and n-propanol.
Monohydric and dihydric alcohols such as butanol, isobutanol, n-octyl alcohol, acyl alcohol, ethylene glycol, propylene glycol and butylene glycol, and ethylene glycol monomethyl ether and ethylene glycol in which one end of the dihydric alcohol is an ether. Examples include monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether. Among them, n-butanol, propylene glycol monopropyl ether, ethylene glycol monobutyl ether and the like are extremely effective film forming agents for the component (a) having a high glass transition point in the present invention. The amount of these film-forming agents added is preferably 0.1 to 15 parts by weight per 100 parts by weight of the components (a), (b) and (c). If the addition amount is less than 0.1 parts by weight, the effect is low, and if it exceeds 15 parts by weight, the amount of residual solvent in the photosensitive film becomes too large and the photosensitive film tends to be sticky.

The film-forming agent may be added before the neutralization with the basic organic compound or after the neutralization. Further, when the electrodeposition coating bath is prepared, the negative photosensitive electrodeposition coating composition may be added after being dissolved or dispersed in water.

Further, a surfactant may be appropriately added to improve the water dispersibility and dispersion stability of the negative photosensitive electrodeposition coating resin composition.

The electrodeposition coating bath can be usually prepared by adding water to a negative photosensitive electrodeposition coating resin composition and dissolving or dispersing it in water. It is preferable that the solid content of the electrodeposition coating bath is in the range of 5 to 20% by weight and the pH is in the range of 6.0 to 9.0 from the viewpoints of bath management and electrodeposition property.

In order to perform electrodeposition coating on a conductive substrate using the electrodeposition coating bath thus obtained, the conductive substrate is immersed as an anode in the electrodeposition coating bath, and usually in the case of the constant current method, 10-100m
DC current of A / dm ² or 50 to 400 V for constant voltage method
Is applied for 10 seconds to 5 minutes. The thickness of the obtained coating film is preferably 5 to 50 μm. At this time, it is desirable to control the temperature in the electrodeposition coating bath to 15 to 30 ° C.

After electrodeposition coating, lift the object to be coated from the electrodeposition coating bath and wash with water,
After draining, it is dried with hot air or the like. At this time, if the drying temperature is high, the coating film is heat-cured and a part of the film is left undeveloped in the developing step after exposure.

Then, the coating film is irradiated with an actinic ray imagewise to photo-cur the exposed portion of the coating film, and the unexposed portion is removed by development to obtain a photo-cured resist pattern. As the light source of the actinic ray, one that emits a ray having a wavelength of 300 to 450 nm, for example, a mercury vapor arc, a carbon arc, a xenon arc or the like is preferably used.

The development can be carried out by spraying alkaline water such as sodium hydroxide, sodium carbonate, potassium hydroxide or the like, or by immersing in alkaline water.

〔Example〕

 The present invention will be described below with reference to examples.

Example 1 1130 g of dioxane was added to a flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel and a nitrogen gas introducing tube, and the mixture was heated to a temperature of 90 ° C. while blowing nitrogen gas while stirring. Methacrylic acid 16 at a constant temperature of 90 ℃
9 g, methyl methacrylate 688 g, ethyl acrylate 83 g,
A liquid prepared by mixing 60 g of n-butyl acrylate and 10 g of azobisisobutyronitrile was dropped into the flask over 2.5 hours, and then the mixture was kept warm at 90 ° C. for 3 hours with stirring. After 3 hours, 3 g of azobisdimethylvaleronitrile was added to dioxane 10
The solution dissolved in 0 g was added dropwise into the flask over 10 minutes, and then the temperature was again kept at 90 ° C. for 4 hours with stirring.

The polymer as the precursor of the component (a) thus obtained had a weight average molecular weight of 39,000, an acid value of 111, and a solid content of the polymer solution of 45.7% by weight. The glass transition point of this polymer was 85 ° C.

Next, in 650 g of this polymer solution, 150 g of EO-modified bisphenol A dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., high-quality product NK ester BPE-200) as component (b), 30 g of benzophenone as component (c) and N, N ' -Tetraethyl-4,
1 g of 4'diaminobenzophenone was added and dissolved. Triethylamine 20 as a basic organic compound was added to this solution.
g was added and dissolved to neutralize the polymer as the precursor of the component (a) in the solution.

Then, while stirring this solution, 4,200 g of ion-exchanged water
Was slowly added dropwise to obtain an electrodeposition coating bath. The pH of this electrodeposition coating bath was 7.7 at 25 ° C.

A glass epoxy copper clad laminate (MCL-E-61 manufactured by Hitachi Chemical Co., Ltd.) (200 mm x 75 mm) was used as an anode in the above electrodeposition coating bath, and a stainless steel plate (SUS304, shape 200 mm x 75 mm x 1 m) was used.
m) was immersed as a cathode, and a DC voltage of 150 V was applied at a temperature of 25 ° C. for 3 minutes to form an electrodeposition coating film (photosensitive film) on the surface of the copper clad laminate. After that, wash with water and drain at 100 ° C for 1
It was dried for 0 minutes (film thickness after drying 10 μm).

To this thing, with a 3KW ultra high pressure mercury lamp through a negative mask 1
After imagewise exposure with a light amount of 00 mJ / cm ^2, the image was developed with a 1 wt% sodium carbonate aqueous solution, and as a result, a step plate (optical density of 0.05 was used as the first step and the optical density of each step was 0.
Using a negative mask that increases by 15) 6 steps of photosensitivity,
Also, a good resist pattern having a high resolution of 50 μm could be formed.

Example 2 1,130 g of propylene glycol monomethyl ether was added to a flask equipped with the same apparatus as in Example 1 and stirred, and the temperature was raised to 100 ° C. while blowing nitrogen gas. When the temperature became constant at 100 ° C, a mixture of 192 g of methacrylic acid, 780 g of methyl methacrylate, 28 g of ethyl acrylate and 20 g of azobisisobutyronitrile was added dropwise to the flask over 3 hours, then 3.5 hours at 100 ° C. It was kept warm with stirring. After 3.5 hours, 8 g of azobisdimethylvaleronitrile was added to propylene glycol monomethyl ether.
A solution dissolved in 100 g was dropped into the flask over 10 minutes,
After that, the temperature was kept at 4 ° C. for 4 hours with stirring again.

The polymer as a precursor of the component (a) thus obtained had a weight average molecular weight of 21,000, an acid value of 126, and the solid content of the polymer solution was 45.8% by weight. The glass transition point of this polymer is 112 ° C.

Next, dipentaerythritol hexaacrylate as a component (b) (manufactured by Nippon Kayaku,
80 g of trade name Kayarad DPHA), 30 g of benzophenone as component (c) and 1 g of N, N'-tetraethyl-4,4'-diaminobenzophenone were added and dissolved.

To this solution, 15 g of propylene glycol monopropyl ether as a film forming agent was added and dissolved, and then 22 g of triethylamine as a basic organic compound was added and further dissolved to obtain a polymer as a precursor of the component (a) in the solution. Neutralized. While stirring this solution, deionized water 3,70
0 g was gradually added dropwise to obtain an electrodeposition coating bath. The pH of this electrodeposition coating bath was 7.5 at 25 ° C.

A glass epoxy copper clad laminate (MCL-E-61 manufactured by Hitachi Chemical Co., Ltd.) was used as an anode in the above electrodeposition coating bath to perform electrodeposition coating in the same manner as in Example 1 to form an electrodeposition coating film. (Photosensitive film) was formed. After that, it was washed with water, drained and dried at 105 ° C. for 10 minutes (film thickness after drying 15 μm).

To this thing, with a 3KW ultra high pressure mercury lamp through a negative mask, 7
After imagewise exposure with a light amount of 0 mJ / cm ² , development with a 1 wt% sodium carbonate aqueous solution resulted in 7 steps of photosensitivity and a good resist pattern with high resolution of 50 μm. Could be formed.

Example 3 To a flask equipped with the same apparatus as in Example 1, 1,130 g of propylene glycol monomethyl ether was added and stirred, and the temperature was raised to 95 ° C while blowing nitrogen gas. temperature
When it reached a constant temperature of 95 ° C, a mixture of 215 g of methacrylic acid, 325 g of methyl methacrylate, 200 g of n-butyl methacrylate, 100 g of styrene, 160 g of methyl acrylate and 5 g of azobisisobutyronitrile was dropped into the flask over 2.5 hours. Then, the mixture was kept warm with stirring at 95 ° C. for 3 hours. After 3 hours, a solution prepared by dissolving 2.5 g of azobisdimethylvaleronitrile in 100 g of propylene glycol monomethyl ether was dropped into the flask over 15 minutes, and then the solution was added again to 4
The mixture was kept warm with stirring at 95 ° C for an hour.

The polymer as a precursor of the component (a) thus obtained had a weight average molecular weight of 47,000, an acid value of 139, and a solid content of the polymer solution of 44.9% by weight. The glass transition point of this polymer was 77 ° C.

Next, in 700 g of this polymer solution, 130 g of ditrimethylolpropane tetraacrylate (trade name, SR-355 manufactured by Sartomer Co.) as the component (b), 30 g of benzophenone as the component (c) and N, N'-tetraethyl-4, 1 g of 4'-diaminobenzophenone was added and dissolved.

To this solution, 26 g of triethylamine as a basic organic compound was added and dissolved to neutralize the polymer as the precursor of the component (a). While stirring this solution, deionize water
3,800 g was gradually added dropwise to obtain an electrodeposition coating bath.
The pH of this electrodeposition coating bath was 7.2 at 25 ° C.

A glass epoxy copper clad laminate (MCL-E-61 manufactured by Hitachi Chemical Co., Ltd.) was used as an anode in the above electrodeposition coating bath to perform electrodeposition coating in the same manner as in Example 1 to form an electrodeposition coating film. (Photosensitive film) was formed. After that, it was washed with water, drained and dried at 105 ° C. for 10 minutes (film thickness after drying 12 μm).

To this one, 8K with a 3KW ultra high pressure mercury lamp through a negative mask
After imagewise exposure with a light amount of 0 mJ / cm ² , development with a 1 wt% sodium carbonate aqueous solution resulted in 7 steps of photosensitivity and a good resist pattern with high resolution of 50 μm. Could be formed.

Example 4 1,130 g of propylene glycol monomethyl ether was added to a flask equipped with the same apparatus as in Example 1 and stirred, and the temperature was raised to 90 ° C. while blowing nitrogen gas. temperature
When the temperature reached 90 ° C, 192 g of methacrylic acid, 714 g of methyl methacrylate, 21 g of methyl acrylate, 73 g of n-butyl acrylate and 10 g of azobisisobutyronitrile were dropped into the flask over 2.5 hours, and then 3 The mixture was kept warm with stirring at 90 ° C. for an hour. After 3 hours, a solution prepared by dissolving 3 g of azobisdimethylvaleronitrile in 100 g of propylene glycol monomethyl ether was added dropwise into the flask over 10 minutes, and then the temperature was again maintained at 90 ° C. for 4 hours with stirring.

The polymer as a precursor of the component (a) thus obtained had a weight average molecular weight of 34,000, an acid value of 125, and a solid content of the polymer solution of 45.1% by weight. The glass transition point of this polymer is 95 ° C.

Next, in 700 g of this polymer solution, 170 g of pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name NK ester A-TMM-3) as component (b), 30 g of benzophenone as component (c) and N, N'- Tetraethyl-4,
1 g of 4'-diaminobenzophenone was added and dissolved.

To this solution, 22 g of triethylamine as a basic organic compound was added and dissolved to neutralize the polymer as the precursor of the component (a), and further 12 g of propylene glycol monopropyl ether as a film forming agent was added and dissolved. .
While stirring this solution, 4,000 g of ion-exchanged water was gradually added dropwise to obtain an electrodeposition coating bath. Of this electrodeposition coating bath
The pH was 7.5 at 25 ° C.

A glass epoxy copper clad laminate (MCL-E-61 manufactured by Hitachi Chemical Co., Ltd.) was used as an anode in the above electrodeposition coating bath to perform electrodeposition coating in the same manner as in Example 1 to form an electrodeposition coating film. (Photosensitive film) was formed. After that, it was washed with water, drained and dried at 105 ° C. for 10 minutes (film thickness after drying 17 μm).

60m with a 3KW ultra-high pressure mercury lamp through a negative mask
After imagewise exposure with a light amount of J / cm ^2, the image was developed with a 1 wt% sodium carbonate aqueous solution.
It was possible to obtain a stepwise photosensitivity and to form a good resist pattern having a high resolution of 50 μm.

Example 5 1,130 g of propylene glycol monomethyl ether was added to a flask equipped with the same apparatus as in Example 1 and stirred, and heated to a temperature of 90 ° C. while blowing nitrogen gas. temperature
When the temperature became constant at 90 ° C, a mixture of 128 g of methacrylic acid, 550 g of methyl methacrylate, 150 g of styrene, 172 g of ethyl methacrylate and 5 g of azobisisobutyronitrile was dropped into the flask over 2.5 hours, and then for 3 hours, 9 hours.
The mixture was kept warm with stirring at 0 ° C. After 3 hours, a solution prepared by dissolving 2.5 g of azobisdimethylvaleronitrile in 100 g of propylene glycol monomethyl ether was added dropwise into the flask over 10 minutes, and then the temperature was again maintained at 90 ° C. for 4 hours while stirring.

The polymer as a precursor of the component (a) thus obtained had a weight average molecular weight of 55,000, an acid value of 101, and a solid content of the polymer solution of 45.3% by weight. The glass transition point of this polymer was 100 ° C.

Next, in 700 g of this polymer solution, 120 g of trimethylolpropane triacrylate (manufactured by Osaka Organic Chemical Industry, trade name biscoat 295) as component (b), and 30 g of urethane acrylate (manufactured by Sartomer Co., trade name C-9501),
30 g of benzophenone as the component (c) and 1 g of N, N'-tetraethyl-4,4'-diaminobenzophenone were added and dissolved.

To this solution, 23 g of triethylamine as a basic organic compound was added and dissolved to neutralize the polymer as the precursor of the component (a), and 15 g of n-butanol as a film forming agent was further added and dissolved. While stirring this solution, 4,100 g of ion-exchanged water was gradually added dropwise. After that, 5 g of n-butanol as a cosolvent was further added and well stirred to obtain an electrodeposition coating bath. The pH of this electrodeposition coating bath is 25 ° C 7.
It was 9.

A glass epoxy copper clad laminate (MCL-E-61 manufactured by Hitachi Chemical Co., Ltd.) was used as an anode in the above electrodeposition coating bath to perform electrodeposition coating in the same manner as in Example 1 to form an electrodeposition coating film. (Photosensitive film) was formed. After that, it was washed with water, drained and dried at 105 ° C. for 10 minutes (film thickness after drying 14 μm).

70m with a 3KW ultra-high pressure mercury lamp through a negative mask
After imagewise exposure with a light amount of J / cm ^2, the image was developed with a 1 wt% sodium carbonate aqueous solution.
It was possible to obtain a stepwise photosensitivity and to form a good resist pattern having a high resolution of 50 μm.

Comparative Example 1 1,130 g of propylene glycol monomethyl ether was added to a flask equipped with the same apparatus as in Example 1 and stirred, and heated to a temperature of 90 ° C. while blowing nitrogen gas. temperature
When the temperature was kept constant at 90 ° C, 169 g of methacrylic acid, 430 g of methyl methacrylate, 247 g of ethyl acrylate, 153 g of n-butyl acrylate and azobisisobutyronitrile 10
The liquid in which g was mixed was dropped into the flask over 2.5 hours, and then the mixture was kept at 90 ° C. for 3 hours while stirring. After 3 hours, a solution prepared by dissolving 3 g of azobisdimethylvaleronitrile in 100 g of propylene glycol monomethyl ether was added dropwise into the flask over 10 minutes, and then the temperature was again maintained at 90 ° C. for 4 hours with stirring.

The weight average molecular weight of the polymer thus obtained is
The acid content was 38,000, the acid value was 109, and the solid content of the polymer solution was 45.1% by weight. However, the glass transition point of this polymer is 39
It was ℃.

Next, 659 g of this polymer solution was added with 150 g of EO-modified bisphenol A dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name NK ester BPE-200), 30 g of benzophenone and N, N'-tetraethyl-4,4'-diaminobenzophene. Non-1 g was added and dissolved.

To this solution, 20 g of triethylamine as a basic organic compound was added and dissolved.

While stirring this solution, 4,200 g of ion-exchanged water was gradually added dropwise to obtain an electrodeposition coating bath. The pH of this electrodeposition coating bath was 7.7 at 25 ° C.

A glass epoxy copper clad laminate (MCL-E-61 manufactured by Hitachi Chemical Co., Ltd.) was used as an anode in the above electrodeposition coating bath, and an electrodeposition coating film (photosensitive film) was prepared by the same method and conditions as in Example 1. Was formed. After washing with water and draining, it was dried at 100 ° C. for 10 minutes (film thickness after drying 15 μm).

To this thing, with a 3KW ultra high pressure mercury lamp through a negative mask 1
After imagewise exposure with a light amount of 00 mJ / cm ² , development with a 1 wt% sodium carbonate aqueous solution resulted in 7 steps of photosensitivity, but the resist shape was round and the resist shape was poor. Atsuta

Further, the negative mask adhered to the photosensitive film during the exposure, and when the negative mask was forcibly peeled off after the exposure, a part of the resist was scratched.

Table 1 shows the results of evaluating the electrodeposition properties and the tackiness between the photosensitive films of Examples 1 to 5 and Comparative Example 1. In addition, as shown in FIG. 1, the evaluation of the adhesiveness between the photosensitive films is performed by stacking the photosensitive films on a glass epoxy copper clad laminate (50 mm × 50 mm) and applying a load of 1.0 kg from the top. After being left in an atmosphere of ° C for 1 hour and then returning to room temperature, it was observed that the photosensitive films were easily peeled off from each other. (◯: The photosensitive films were easily peeled off without sticking, Δ: Slightly sticking, x: Completely sticking and the photosensitive film was not peeled.) It is apparent from Table 1 that in Examples 1 to 5, It can be seen that a uniform photosensitive film having a film thickness of 10 to 17 μm was obtained with a good appearance, and it was a hard film that did not flicker and stick even when the photosensitive films were stacked. Of course, as described in each of the embodiments, the photosensitivity is good, and the resist pattern is rectangular, so that a high-resolution resist pattern can be obtained.

On the other hand, in Comparative Example 1 (the glass transition point of the polymer used is as low as 39 ° C., which is outside the range of the present invention), the electrodeposition property is as good as that of the Example, but the feeling There is a problem that the light films are soft, and when the photosensitive films are stacked on each other, they easily stick to each other and cannot be peeled off. Also, the resist shape is round and poor.

On the other hand, in Examples 1 to 5, when a polymer in which a large amount of methyl methacrylate was copolymerized was used (Examples 1, 2,
The appearance of 4) was better than that of gloss.
It is also shown that when the film-forming agent is used (Examples 2, 4, and 5), the film thickness of the electrodeposition coating film (photosensitive film) can be increased.

As described above, as shown in Examples, by using a polymer having a high glass transition point, and by using a film forming agent suitable for it as needed, a thick film having a good appearance, and stacking photosensitive films with each other. It is possible to easily obtain a photosensitive film having a high hardness that does not stick even by a single electrodeposition coating, and it is possible to obtain a good resist pattern having a high sensitivity of the photosensitive film and a high resolution.

〔The invention's effect〕

By using an electrodeposition coating bath containing the negative photosensitive electrodeposition coating resin composition of the present invention, the electrodeposition property is good, hard,
A photosensitive film that does not stick to each other can be easily obtained, and a high-resolution resist pattern can be obtained with good workability by exposing and developing the photosensitive film.

The resist obtained by utilizing the present invention can be used as a relief, or can be applied to the formation of a photoresist for etching or plating by using a copper clad laminate as a basis.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a method for evaluating tackiness in Examples. 1 ... Photosensitive film, 2 ... Glass epoxy copper clad laminate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Akahori 4-13-1, Higashimachi, Hitachi City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Ibaraki Laboratory (72) Inventor Takuro Kato 4-13-1, Higashimachi, Hitachi City, Ibaraki Prefecture No. Hitachi Chemical Industry Co., Ltd.Yamasaki Plant (72) Inventor Yuji Yamazaki 1382-12 Shimoishigami, Otawara-shi, Tochigi Dainihon Paint Co., Ltd.Nasu Plant (72) Toshiya Takahashi 1382 Shimoishi, Otawara, Tochigi Prefecture No. 12 Dainichi Paint Co., Ltd. in Nasu Factory (72) Inventor Toshihiko Shiotani 1382-12 Shimoishigami, Otawara-shi, Tochigi Prefecture Dainichi Paint Co., Ltd. in Nasu Factory (72) Yoshihisa Nagashima Shimoishigami, Otawara City, Tochigi Prefecture 1382-12 12 Dainichihon Paint Co., Ltd. Nasu factory (56) Reference JP-A-2-20873 (JP, A)

Claims (5)

(57) [Claims] 1. A polymer obtained by copolymerizing (a) a polymerizable monomer containing acrylic acid and / or methacrylic acid with an acid value of 20 to 300 and a glass transition point of 75 to 120 ° C. is neutralized with a basic organic compound. A negative type photosensitive electrodeposition coating resin composition containing the above polymer, (b) a water-insoluble monomer having two or more photopolymerizable unsaturated bonds in the molecule, and (c) a water-insoluble photoinitiator. 2. The negative type as claimed in claim 1, wherein the polymer as the component (a) is a copolymer obtained by copolymerizing methyl methacrylate in an amount of 60 to 85 parts by weight based on 100 parts by weight of the total amount of the polymerizable monomers constituting the polymer. Photosensitive electrodeposition coating resin composition. 3. Further, 1 to 2 hydroxyl groups are contained in the molecule.
The negative photosensitive electrodeposition coating resin composition according to claim 1 or 2, further comprising a film-forming agent composed of a hydrophilic organic solvent. 4. A film forming agent comprising a hydrophilic organic solvent having 1 to 2 hydroxyl groups in the molecule is at least one selected from the group consisting of n-butanol, propylene glycol monopropyl ether and ethylene glycol monobutyl ether. 4. The negative photosensitive electrodeposition coating resin composition according to claim 3. 5. An electrodeposition coating bath containing the negative-type photosensitive electrodeposition coating resin composition according to any one of claims 1 to 4.