JPH03250066A - Positive-type photosensitive anionic electrodeposition coating resin composition, and bath and method for electrodeposition coating using the composition - Google Patents

Abstract

PURPOSE:To prepare the title compsn. having an excellent photosensitivity and giving a resist film excellent in the mechanical properties by compounding a specific compd. into a resin obtd. by neutralizing a (meth)acrylic resin copolymerized with a polymerizable monomer of which a homopolymer has a glass transition point of 0 deg.C or lower. CONSTITUTION:The title compsn. is prepd. by compounding 30-95 pts.wt. resin obtd. by neutralizing, with an acid, a (meth)acrylic resin obtd. by the copolymn. of two essential monomers, i.e., a polymerizable monomer of formula I (wherein R<1> is H or methyl; R<2> and R<3> are each H or alkyl; and (n) is 1-6) [e.g. N,N- dimethylaminoethyl (meth)acrylate] and a polymerizable monomer of which a homopolymer has a glass transition point of 0 deg.C or lower (e.g. n-butyl acrylate) with 5-70 pts.wt. compd. of formula II (wherein R<4> is alkyl; R<5> is H, alkyl, alkoxy, or nitro; R<6> is formula III; and (m) is 0-2, (n) is 1-3, and (m+n) is 1-3).

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a positive photosensitive cationic electrodeposition paint resin composition used for forming resist patterns in the manufacture of printed circuit boards, etc. Concerning coating baths and electrodeposition coating methods.

(Prior Art) Conventionally, as a method for forming a resist pattern on the surface of a substrate, a method is often used in which a photosensitive layer is formed on the surface of the substrate, and then, after being irradiated with actinic rays, the layer is developed. Various methods are employed for forming the photosensitive layer in this step.

For example, a method using a photosensitive resin composition solution (coating liquid) such as dip coating, roll coating, or curtain coating, or a method in which a photosensitive layer is previously formed on a base film (hereinafter referred to as photosensitive film) is applied to the substrate surface. A method of laminating layers using a laminator or the like is known. Among these methods, the method using a photosensitive film is currently available because it can easily form a photosensitive layer with a uniform thickness! ￥
This method has been adopted as the mainstream method in the field of printed circuit board manufacturing.

(Problems to be Solved by the Invention) Recently, as printed circuit boards have become denser and more precise, resist patterns of higher quality have become necessary. That is, it is desired that the resist pattern be free of pinholes and that is in close contact with the surface of the underlying substrate. It is known that the currently mainstream method of laminating photosensitive films has limitations in meeting such demands. This method eliminates dents and uneven polishing during substrate manufacturing.

It is difficult to follow the unevenness of the substrate surface caused by non-uniform copper plating pits on the surface of the glass cloth mesh 9 in the inner layer of the substrate, and it is difficult to obtain sufficient adhesion. This difficulty can be avoided to some extent by laminating the photosensitive films under reduced pressure (see Japanese Patent Publication No. 59-3740), but this requires special and expensive equipment.

For these reasons, solution coating methods such as dip coating, roll coating, and curtain coating have been reconsidered in recent years.

However, with these methods, it is difficult to control the film thickness.

There are problems such as insufficient uniformity of film thickness and occurrence of pinholes.

Recently, a new method of forming a photoresist film by electrodeposition coating has been proposed (Japanese Patent Laid-Open No. 62-23549
(See Publication No. 6). According to this method, α) The adhesion of the resist is improved ■ Good ability to follow irregularities on the substrate surface ■ A photoresist film with a uniform thickness can be formed in a short time C) The coating liquid is an aqueous solution, so it is easy to use in one work environment. It has the advantage of preventing pollution and causing no problems in terms of disaster prevention. Furthermore, if the electrodeposition paint is a cationic type, the coating film (photoresist film) obtained by electrodeposition coating will not contain metal ions, and problems such as residual development can be prevented, which is more desirable.

Several proposals have been made in the past regarding positive type photosensitive cationic electrodeposition paints that are considered to be particularly effective in manufacturing printed circuit boards having through holes. Most of them are of the type in which a photosensitive group of 1,2-naphthoquinonediazide is introduced into the polymer molecule (for example, JP-A-61-20629
No. 3, JP-A-63-221178, 9%, JP-A-64-46
From the viewpoint of electrodeposition coating, these methods have advantages such as easy control of the electrodeposition solution, but on the other hand.

From the standpoint of positive photoresists, there have been problems such as insufficient photosensitivity, low mechanical strength of the resist film, and difficulty in finely adjusting various properties.

On the other hand, when forming a positive photoresist using a solution coating method used in the manufacturing process of semiconductor devices such as ICs and LSIs, most of the composition of the positive photoresist used is novolak resin, vinyl phenol resin, etc. It is a mixture of an alkali-soluble resin and a photosensitizer represented by an ester compound of benzophenone having two or more hydroxyl groups and 1,2-naphthoquinonediazide sulfonic acid (for example, 1%
No. 8, JP-A-63-279246, JP-A-64-11
No. 259, Japanese Unexamined Patent Publication No. 64-17049). These resins have good photosensitivity and mechanical properties of the resist film when viewed from the performance as BON-type photoresists, but it is natural that these resins do not have amino groups, which are essential for cationic electrodeposition paints. However, it cannot be used as an electrodeposition paint as it is.

Furthermore, as the resin that is the main component of the photoresist used in the manufacture of printed circuit boards, which is the main application of the present invention, (meth)acrylic resin has traditionally been commonly used due to its physical properties and ease of handling. The ester compound of benzophenone with two or more hydroxyl groups and 1.2 naphthoquinonediazide sulfonic acid, which is commonly used as a photosensitizer, has extremely poor compatibility with (meth)acrylic resin, so it cannot be used as the main component of photosensitizers. It cannot be used in combination with (meth)acrylic resin.

As described above, the positive photoresist compositions formed by electrodeposition coating that have been proposed to date have problems such as low photosensitivity and mechanical properties of the resist film, and furthermore, it is difficult to finely adjust the properties. Although positive photoresists formed by coating methods using solutions still have good properties, it has been impossible to convert them into electrodeposition paints for various reasons.

(An Unsuccessful Means to Solve the Problem) Therefore, as a result of intensive study, the present inventors have developed an amino group-containing resin for use in a cationic electrodeposition coating.

We selected a (meth)acrylic resin, which is commonly used as the main component of photoresists currently used in the manufacture of printed circuit boards, and in order to make the (meth)acrylic resin an excellent electrodeposition coating, the glass transition point of the homopolymer was It is essential to copolymerize a polymerizable monomer at 0° C. or lower, and there is no conventional compatibility with the (meth)acrylic resin obtained in this way.

A positive photosensitive cationic electrodeposition coating resin composition that can be formed by the desired electrodeposition coating in combination with a good photosensitizer and has excellent photosensitivity and mechanical properties of a resist film, and an electrodeposition coating using the same. The bath and electrodeposition coating methods were discovered.

That is, 2 the present invention provides (a) - a polymerizable monomer 1 represented by the pattern (1);
(,! (In the formula, Ice is hydrogen or a methyl group, R2 and R3 are each independently hydrogen or an alkyl group, and n is an integer of 1 to 6) and the homopolymer has a glass transition point of 0°C or lower. Copolymerized with polymerizable hexamer as an essential component (meth)
Acrylic resin neutralized with acid (a) and (
30 to 95 parts by weight based on 100 parts by weight of the total amount of b) and (b) - a compound represented by Monna (U) (in the formula
1 (, 4 is an alkyl group, P is hydrogen, an alkyl group, an alkoxy group, or a nitro group, Rat: 1, 1m is an integer of 0 to 2, n is an integer of 1 to 3, and the sum of 1m and n is Total amount of (a) and (b) (selected to be an integer from 1 to 3) 1
The present invention relates to a positive photosensitive cationic electrodeposition coating resin composition having a weight of 5 to 70 parts by weight per 00 parts by weight, and an electrodeposition coating bath using the same.

Further, the present invention relates to an electrodeposition coating method characterized in that a substrate whose surface is covered with metal is immersed in the electrodeposition coating bath, and a DC voltage is applied using the substrate as a cathode.

According to the present invention, it is possible to provide a positive photoresist that is more suitable for electrodeposition coating than ever before and has excellent photosensitive properties and resist mechanical properties. It can take full advantage of many advantages.

The present invention will be described in detail below.

For the (meth)acrylic resin which is the component (a), it is essential to first use a polymerizable monomer represented by the general formula (I).

As the polymerizable monomer represented by general formula (1).

For example, aminoethyl (meth)acrylate, Nter
t-butylaminoethyl (meth)acrylate), N, N
-dimethylaminoethyl (meth)acrylate, N, N
-diethylaminoethyl (meth)acrylate, N, N
-dimethylaminopropyl (meth)acrylate, N,
Examples include N-dimethylaminobutyl (meth)acrylate. These can be used alone or in combination with Class 211 or higher.

The amount of the polymerizable monomer represented by the general formula +1) is preferably 4 to 60 parts by weight, based on 100 parts by weight of the total amount of copolymerizable monomers forming the polymer (a). It is more preferable that the amount is 40 parts by weight. When the amount used is less than 4 parts by weight, the acid is added to the positive photosensitive cationic electrodeposition coating resin composition of the present invention as described below.

When water is added and dispersed, the water dispersibility and water dispersion stability are poor and the composition tends to settle, and if the amount used exceeds 60 parts by weight, the appearance of the coating after electrodeposition may be poor.

Another essential component of the (meth)acrylic resin, which is component (a), is a polymerizable monomer whose homopolymer glass transition point is 0° C. or lower. A polymerizable monomer whose homopolymer glass transition point is 0°C or lower means that the glass transition point of a polymer obtained by homopolymerizing the monomer is 0°C or lower. The glass transition point is measured by a conventional thermal analysis method, but preferably by differential scanning calorimetry (D
SC). Here, the homopolymer has a glass transition point of 0° C. or lower.

Ethyl acrylate, isopropyl acrylate.

n-globyl acrylate, inbutyl acrylate,
There are n-hexyl methacrylate, n-octyl methacrylate, n-decyl methacrylate, etc. Among them, n-
-Butyl acrylate and 2-ethylhexyl acrylate are preferred. These polymerizable monomers may be used alone or in combination of two or more, and the amount used is 100% of the total amount of copolymerizable monomers forming the polymer that is the component la).
It is preferably 5 to 75 J [parts by weight].

More preferably, the amount is 20 to 60 parts by weight.

When the amount used is less than 5 polymerized parts, the glass transition point of the polymer becomes high, and there is a possibility that a film cannot be formed when the electrodeposition paint combined with the photosensitive agent (component (b)) is electrodeposited. Moreover, if it exceeds 75 parts by weight, the glass transition point of the polymer will be too low and the coating film after electrodeposition will tend to be sticky.

The (meth)acrylic resin which is the component (a) includes K other than the above polymerizable monomers, such as methyl acrylate.

Methyl methacrylate, ethyl methacrylate.

Butyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate.

2.42 - One or more monopolymerizable motumers such as trifluoroethyl methacrylate, diacetone acrylamide, acrylonitrile, styrene, and vinyltoluene can be used in combination for copolymerization. The lid used is (a)
A total of 110 copolymerized monomers forming the resin that is a component of
0] It can be used in an amount of 911 parts or less relative to parts iii.

Synthesis of (meth)acrylic resin, which is a component of la).

The polymerizable monomer was dissolved in an organic solvent to form azobisisobutyronitrile, azobisdimethylvaleronitrile/', peroxy[
It can be obtained by general solution polymerization using a polymerization initiator such as benzoyl compound. In this case, the organic solvent to be used is preferably a hydrophilic organic solvent such as dioxane, methoxyethanol, ethoxyethanol, diethylene glycol, etc., considering that it will be used in an electrodeposition coating.

If a hydrophobic organic solvent such as toluene, xylene, or benzene is mainly used, it is necessary to distill off the solvent after resin synthesis and replace it with the hydrophilic organic solvent. The average molecule t of the resin (in terms of standard polystyrene) is s, o o
A range of o to 150,000 is preferred.

If it is less than 5,000, the mechanical strength of the resist is weak.

If it exceeds 150,000, the electrodeposition coating properties tend to be poor and the appearance of the coating film tends to be poor.

The (meth)acrylic resin used as component (a) is (
30 parts per 100 parts by weight of the total of a) and (b)
~95 parts by weight. The amount is preferably 50 to 90 parts by weight. If the amount used is less than 30 parts by weight, the water dispersibility and water dispersion stability in the electrodeposition bath will be poor, and if it exceeds 95 parts by weight, the proportion of the photosensitizer, which is the component tb), will decrease and the sensitivity to light will decrease. .

Next, the compound represented by the general formula (■), which is the component (b), will be explained.

R4 in Ichimonana+IIl is an alkyl group, preferably an alkyl group having 1 to 18 carbon atoms, particularly 1 to 18 carbon atoms.
The alkyl group 9 of 12 is preferably a methyl, n-propyl, inglovir, n-octyl, 2-ethylhexyl, n-dodecyl group, or the like.

Bs is hydrogen, methyl, ethyl, and n-propyl.

Inglovir, n-butyl, isobutyl, t-phthyl,
Alkyl groups such as n-hexyl, methoxy.

Any one is selected from alkoxy groups such as ethoxy, propoxy, butoxy groups, and nitro groups.

And m is an integer from 0 to 2, and n is an integer from 1 to 3.
The sum of and n is chosen to be an integer between 1 and 3.

The method for synthesizing the compound of general formula (II) is not particularly limited, but preferably trihydroxybenzoic acid ester (e.g. gallic acid ester), dihydroxybenzoic acid ester, hydroxybenzoic acid ester (e.g. salicylic acid ester)
It can be obtained by condensing benzoic acid ester derivatives having a hydroxyl group on the benzene ring with 1,2-benzoquinonediazide-4-sulfonic acid chloride or 1,27naphthoquinonediazide-4-sulfonic acid chloride. To give a specific example, a benzoic acid ester conductor having a hydroxyl group on the benzene ring and 1,2-benzoquinonediazide-4-sulfonic acid chloride or Vi
l. Add an organic solvent to the mixture of 2-naphthoquinonediazide-4-sulfonic acid chloride and dissolve, stirring while stirring.
This includes triethylamine, pyridine, and sodium carbonate (
- For boat fishing, a base such as an aqueous solution is added dropwise, and after 2 drops, the mixture is further stirred for 10 minutes to 8 hours to react.

During this time, the temperature is preferably kept in the range of 30 to 50°C, with 9% of room temperature to 80°C.

In this way, benzoquinonediazide sulfonic acid chloride or naphthoquinonediazide sulfonic acid chloride may be entirely condensed to the hydroxyl group, or some of the hydroxyl groups may be left and the rest may be condensed. SaraKh
As can be seen from the above-mentioned synthesis examples, there is a possibility that a mixture of compounds having different amounts of unreacted hydroxyl groups in one molecule may be obtained, but it is not necessary to isolate them.

In any case, it is a compound of general formula (II) selected such that m is an integer of 0 to 2, n is an integer of 1 to 3, and the sum of 2m and n is an integer of 1 to 3. For example, both single products and mixtures fall within the scope of the present invention.

(Usage amount F of the compound of general formula (II) which is a component of bl
5 to 100 parts by weight of i (al and (b))
It is said to be 70 parts by weight. More preferably, the amount is 10 to 50 parts by weight. If the amount used is less than 1 part by weight, the sensitivity to light will decrease, and if it exceeds 70 parts by weight, water dispersibility and water dispersion stability in an electrodeposition bath will deteriorate.

In addition to the above-mentioned components (a) and (b), the positive-working photosensitive cationic electrodeposition paint resin composition of the present invention may contain a small amount of a quinonediazide compound used in two ordinary positive-working photosensitive resin compositions. can.

Examples of the quinonediazide compound include 9, for example, 3,4-
1-lihydroxybenzophenone-1,2-naphthoquinone diazide-5-sulfonic acid ester.

2,3.4.4'-Tetrahydroxybenzophenone-
Examples include 1,2-naphthoquinonediazide-5-sulfonic acid esters of polyhydroxybenzophenone such as 1.2-naphthoquinonediazide-5-sulfonic acid ester. The amount of these quinonediazide compounds used is preferably 10 parts by weight or less based on 100 parts by weight of the total amount of components (a) and (b). If it exceeds 10 parts by weight, the compatibility of the Al component with the (meth)acrylic resin tends to decrease, and the water dispersion stability tends to decrease.

Furthermore, a sensitizer can also be blended into the positive photosensitive cationic electrodeposition coating resin composition of the present invention.

Examples of the sensitizer include virol, imidazole,
Nitrogen-containing compounds having active hydrogen such as triazole, indole, benzimidazole, oxazolidone, piperidone, hydantoin, glycine, barbylic acid and derivatives thereof can be mentioned. The amount of these sensitizers used is preferably 30 parts by weight or less based on 100 parts by weight of the total amount of components (a) and lb). If it exceeds 30 parts by weight, the solubility of the resist increases during development and the residual film rate tends to decrease.

In the positive photosensitive cationic electrodeposition coating resin composition of the present invention, dyes, pigments, plasticizers, adhesion promoters, inorganic fillers, etc. can also be used as appropriate.

In order to convert the positive photosensitive cationic electrodeposition paint resin composition of the present invention, which mainly contains the above-mentioned +8) and fbl components, into an electrodeposition paint, components (a) and (b) are first prepared.

Furthermore, it is desirable that the other components mentioned above, which are used as necessary, are uniformly dissolved in the hydrophilic organic solvent, but it is not necessary to be particular about this. The hydrophilic organic solvent mentioned here includes dioxane, methoxyethanol, ethoxyethanol, diethylene glycol, and the like. These solvents may be used alone or in combination of two or more, and the amount used is preferably 300 parts by weight or less per 100 parts by weight of the total solid content.

Next, acid is added to this solution to form the (meta) component of fa).
By neutralizing the amine groups contained in the acrylic resin, the two compositions can be easily water-solubilized or water-dispersed. The acid used here includes, for example, acetic acid, lactic acid, phosphoric acid, etc., although there is no limit to the percentage.

These can be used alone or in combination of two or more. The amount of these acids used is 0.4 to 1.0 per equivalent of the amino group in the (meth)acrylic resin, which is the Al component.
Equivalent amounts are preferred. If the amount is less than 0.4 equivalent, the water dispersion stability in the electrodeposition coating bath will decrease, and if the amount exceeds 0, the thickness of the coating film (photosensitive layer) after electrodeposition will not be thin, and storage stability will also decrease. The tendency to do this is undesirable.

Next, water is added to dissolve or disperse the positive photosensitive cationic electrodeposition coating resin composition in water to prepare an electrodeposition coating bath. The solid content of the electrodeposition coating bath is usually 5 to 20% by weight, and the pH
is preferably in the range of 3 to 9.

If the pH is less than 3, the electrodeposited film may be redissolved and no film will be formed as a result, while if the pH is more than 9, dispersion may deteriorate and electrophoresis may become difficult.

In order to adjust the pH to the above-mentioned preferred range, the above-mentioned acid may be added later to adjust the pH.

In addition, nonionic additives are used to improve the water dispersibility and dispersion stability of positive photosensitive cationic electrodeposition paint resin compositions.

Positive io? , surfactants such as anions can also be added as appropriate.

Furthermore, a hydrophobic solvent such as toluene, xylene, 2-ethylhexyl alcohol, etc. can be added as appropriate to increase the amount of coating during electrodeposition coating.

The electrodeposition coating bath thus obtained was used to coat the substrate surface (
In this case, the substrate surface is iron or aluminum.

(Need to be covered with metals such as copper, zinc, other metals and alloys), the substrate is immersed in an electrodeposition coating bath with the substrate as a cathode, and a DC voltage of usually 50 to 400V is applied for 10 minutes. The application is carried out for a period of seconds to 5 minutes. At this time, it is desirable to control the temperature of the electrodeposition coating bath at 15 to 30°C.

After electrodeposition coating, the object to be coated is taken out of the electrodeposition coating bath, washed with water, drained, and then dried with hot air. At this time, if the drying temperature is high, there is a risk that the quinonediazide group in the positive photosensitive cationic electrodeposition paint resin composition will decompose.
It is preferable to dry it below.

The thickness of the coating film (photosensitive layer) obtained in this way is 2 to 50 μm.
is preferred. If the film thickness is less than 2 μm, developer resistance is low;
Furthermore, when used in the manufacture of printed circuit boards, for example, when a resist pattern is formed and then etched, the resistance to etching liquid and etch factor tend to be poor, and if the film thickness exceeds 50 μm, the resolution of the resist pattern decreases. There are things to do.

Next, the coating film is imagewise irradiated with actinic rays to photodecompose the exposed areas, and then the exposed areas are removed by development to obtain a resist pattern.

Examples of active light sources include those that emit light with a wavelength of 300 to 450 nm2, such as a mercury vapor arc.

Carbon arc, xenon arc, metal halide arc, etc. are preferably used.

Development is usually carried out by spraying alkaline water such as sodium hydroxide, sodium carbonate, or potassium hydroxide, or by immersing the film in alkaline water.

(Example) The present invention will be explained below with reference to Examples.

First, a method for synthesizing component (a) and component (b) used in Examples will be described.

Synthesis of (meth)acrylic resin as component (a) (a-1) Add 900 g of dioxane to a flask equipped with a stirrer, a reflux condenser, a thermometer, two dropping funnels, and a nitrogen gas introduction tube,
While stirring, nitrogen gas was blown into the mixture and the mixture was heated to a temperature of 90°C. When the temperature became constant at 90°C, N,N-dimethylaminoethyl acrylate 1509. A mixture of methyl methacrylate 3009, 2-ethylhexyl acrylate 5509 and azobisin butyronitrile 109 was added dropwise into the flask over 25 hours, and then kept at 90° C. with stirring for 3 hours. After 3 hours, a solution of 3 g of azobisisobutyronitrile dissolved in 100 g of dioxane was added dropwise to the flask over 10 minutes under internal pressure, and then kept at 90° C. for 4 hours with stirring.

The weight average molecular weight of the resin (al component) thus obtained was 49,000. The amine value was 59. The solid content of the resin solution was 50.5% by weight.

(a-2) Add dioxane 11309 to a flask equipped with the same equipment as in (a-1), and blow in nitrogen gas while stirring.
It was heated to a temperature of 0°C. When the temperature became constant at 90°C, N,N-diethylaminoethyl methacrylate 1
309. 330 g of methyl methacrylate, 4609 of n-butyl acrylate, 809 of 2-hydroxyethyl acrylate and 10 g of azobisisobutyronitrile,
2. ．． The mixture was added dropwise into the flask over a period of 5 hours, and the mixture was kept at a temperature of 90° C. for 3 hours while stirring. After 3 hours, add 3g of azobisisobutyronitrile to 10% of dioxane.
A solution dissolved in 0 g was added dropwise into the flask over 10 minutes, and then kept at 90° C. for 4 hours while stirring.

The weight average molecular weight of the resin, component (a), thus obtained was 61,000. The amine value was 40. The solid content of the resin solution was 45.1% by weight.

(b) Synthesis of photosensitive agent (b-1) 2-ethylhexyl gallate 28.29 (0.1 mo
A solution of 80.4 g (0.3 mo/) of e) and 1,2-naphthoquinonediazide-4-sulfonic acid chloride dissolved in 800 g of dioxane was heated to 40°C with stirring, and 32 g of triethylamine was added to 30 g of dioxane. It was dripped over several minutes. After the dropwise addition, the reaction was further carried out at 40°C for 3 hours, and then 1 reactant was reduced to 0. The mixture was poured into an aqueous solution of IN hydrochloric acid, and the resulting precipitate was purified and treated with F to give ester compound 919 of 2-ethylhexyl gallate and 1,2-naphthoquinonediazide-4-sulfonic acid.

Example 1 80g of resin solution (a-1) (solid content 40.491K (
Photosensitizer 129 (b-1) and 1.4 g of acetic acid were dissolved and then 400 g of water was slowly added dropwise to disperse the solution in water to obtain an electrodeposition bath (pH 6.1).

Example 2 To the resin solution 909 (solid content 40.6 g) of (a-2) was added (
The photosensitizer 59 of b-1) and 0.9 g of acetic acid were dissolved and then dispersed in water while slowly dropping water + OOGL to obtain an electrodeposition bath (pH 6.0).

A stainless steel plate (SUS304) (shape 200 mm
A 75 mm x 1 mm 1 piece was immersed as an anode, and a DC voltage of 150 V was applied for 3 minutes at a temperature of 25° C. to form an electrodeposition coating film (photoresist film) on the surface of the copper clad laminate. Thereafter, it was washed with water, drained, and dried at 80° C. for 15 minutes. The film thickness after drying was about 8 μm in all Examples 1 to 4.

Next, these coating films were imagewise exposed to a 3 kW ultra-high pressure water lamp through a photomask, and then developed with a 1 liter aqueous sodium carbonate solution. In order to evaluate the photosensitivity at this time, a step tablet (with an optical density of 0.05 as the first step,
As a result of measuring the exposure amount to obtain three stages (using a photomask in which the optical density increases by 0.15 for each stage), the sensitivity was as high as 100 mJ/am'' in all examples. The resist patterns obtained are all 50μ
It was confirmed that the resolution was as high as m.

(Effect of the invention) A resist pattern with high sensitivity and high resolution is formed by applying the electrodeposition coating method of the present invention to an electrodeposition coating bath using the positive photosensitive cationic electrodeposition paint resin composition of the present invention. can do.

By using the present invention, the obtained resist can be used as a relief, or a photoresist for etching or plating using a copper-clad laminate as a base can be formed.

Claims (1)

[Claims] 1. (a) Polymerizable monomer represented by the general formula (I) ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ (I) (In the formula, R^1 is hydrogen or a methyl group, R^ 2 and R^3
are each independently hydrogen or an alkyl group, n is an integer of 1 to 6) and a polymerizable monomer whose homopolymer glass transition point is 0°C or lower are copolymerized as essential components (
meth) Acrylic resin neutralized with acid (a)
30 to 95 parts by weight based on 100 parts by weight of the total amount of (b) and (b) a compound represented by general formula (II) ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ (II) (in the formula, R^ 4 is an alkyl group, R^5 is hydrogen, an alkyl group, an alkoxy group, or a nitro group, R^6 is a numerical formula, a chemical formula, a table, etc., m is an integer from 0 to 2, and n is 1 to 3. is an integer of
The sum of m and n is selected to be an integer from 1 to 3) (a
A positive type photosensitive cationic electrodeposition coating resin composition containing 5 to 70 parts by weight based on 100 parts by weight of the total amount of (a) and (b). 2. The positive-working photosensitive cationic electrodeposition coating resin composition according to claim 1, wherein the polymerizable monomer whose homopolymer has a glass transition point of 0 DEG C. or lower is n-butyl acrylate and/or 2-ethylhexyl acrylate. 3. The positive-working photosensitive cationic electrodeposition coating resin composition according to claim 1 or 2, wherein R^4 in the compound represented by general formula (II) is an alkyl group having 1 to 12 carbon atoms. 4. An electrodeposition coating bath comprising the positive photosensitive cationic electrodeposition coating resin composition according to claim 1, 2 or 3. 5. An electrodeposition coating method, characterized in that a substrate whose surface is covered with metal is immersed in the electrodeposition coating bath according to claim 4, and a DC voltage is applied using the substrate as a cathode.