JP3186923B2 - Positive photosensitive anion electrodeposition resist composition and pattern forming method using the composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive resist which is excellent in operation stability at the time of electrodeposition, has good coating workability, and has high reliability in conductor image formation, and is particularly suitable as an etching resist for manufacturing printed wiring boards. The present invention relates to a photosensitive anion electrodeposition resist composition and a method for forming a pattern using the resist composition.

[0002]

2. Description of the Related Art Printed wiring boards used for electronic equipment and the like are mainly formed on an insulating substrate having a conductor layer on the surface thereof.
It is manufactured by a subtractive method using a circuit pattern formed by a pattern printing method using screen printing or a photolithography method using a photosensitive dry film. However, recently, with the high density and high precision of printed wiring boards, finer circuit patterns and smaller through-hole diameters have been required. Various methods have been proposed for use.

As a composition for forming a positive photosensitive electrodeposition resist, for example, a resin in which quinonediazidesulfonic acid is bonded to a base resin via a sulfonic ester bond to a base resin such as an acrylic resin having an ion-forming group. (See JP-A-61-206293); hydroxylamine and quinonediazide sulfonic acid bonded to a base resin such as an acrylic resin having an ion-forming group via a urethane bond and a sulfonimide bond. Composition containing resin as a main component (JP-A-1-121
No. 375); an acrylic resin and an epoxy compound obtained by copolymerizing a polymerizable monomer having a relatively long side chain having an acid group such as a carboxyl group at the terminal, and an aromatic compound having a phenolic hydroxyl group. Composition containing as a main component a mixture of a photosensitive agent obtained by reacting an aromatic or heterocyclic carboxylic acid and a quinonediazide sulfonic acid halide (see JP-A-2-42446); A composition in which a compound or resin in which quinonediazidesulfonic acid and quinonediazidesulfonic acid are bonded via a urethane bond and a sulfonimide bond is mixed with a base resin such as an acrylic resin having an ion-forming group (see JP-A-2-289660); In addition, quinonediazide sulfonic acids are introduced through a sulfonic ester bond to form phenolic water. Compositions in which the photosensitive resin having a group and a carboxyl group or an amino group in the same polymer molecule as the main component (see JP-A-61-206293);
A composition comprising a mixture of a polymer having a carboxyl group and a polymer having a phenolic hydroxyl group in which quinonediazide sulfonic acids are introduced via a sulfonic acid ester bond (JP-A-63-141048, JP-A-3-1004)
No. 073); a composition containing as a main component a mixture of an acrylic resin having a carboxyl group, an aromatic carboxylic acid ester having a phenolic hydroxyl group and a sulfonic acid ester of a quinonediazide (Japanese Patent Application Laid-Open No. Hei 3-1000074).
Patent Reference); a block copolymer comprising a polymer segment having no carboxyl group and a polymer segment having a carboxyl group, an electrodeposited positive resist composition comprising an alkali-soluble polyphenol and a positive photosensitive agent, and the composition. A water-soluble or water-dispersible composition such as a resist composition in which a photosensitive agent is combined with other components (see JP-A-3-281671) has been proposed.

[0004]

However, the above-mentioned conventional composition has the following problems, and it is desired to solve the problems.

That is, in a resin system in which a photosensitive group is introduced via a sulfonic acid ester group, a sulfonic acid ester is formed by a dehydrohalogenation reaction between a sulfonic acid halide and a hydroxyl group such as a phenolic hydroxyl group in the resin. Need to introduce a quinonediazide group. This reaction is a polymer reaction, and it is difficult to quantitatively introduce a photosensitive group. In addition, the by-product halogenate is removed after the reaction,
It is difficult to purify, it takes a long time to produce, and the yield is poor.

Further, in order to avoid a polymer reaction that generates by-products, naphthoquinonediazidesulfonic acid halide is reacted with hydroxyamines to form a bond by a sulfonamide bond, and further reacted with a diisocyanate such as toluene diisocyanate. The method of introducing an intermediate having a photosensitive group having an isocyanate residue obtained by reacting it with a resin having a hydroxyl group is preferable in that the yield in the polymer reaction is high and a purification step is unnecessary, but There is a problem that the process for obtaining the body is complicated and takes a long time.

Further, in the case where a photosensitive group is bonded to these resins, since the photosensitive groups are randomly arranged in the resin, when this is used as an aqueous dispersion, the surface of the particles has high hydrophobicity. The portion containing the group is easily exposed. as a result,
Aqueous dispersions have poor stability and are prone to sedimentation, and azide groups tend to come into contact with basic substances such as amines, which are often present in the aqueous layer, resulting in degradation of azide groups and reduced photosensitivity. This is a major drawback for an electrodeposition type resist that requires the stability of the aqueous dispersion during the period.

On the other hand, in a resin system in which a photosensitive group is introduced via a sulfonic acid ester group, the sulfonic acid ester group is easily hydrolyzed, and storage stability as an electrodeposition resist solution and operation stability of a bath are further improved. descend. In the method of introducing a photosensitive group via a sulfonic acid imide bond and a urethane bond, the problem relating to hydrolysis is greatly improved, but the dissolution rate of the exposed portion in a developer is slow, and development is performed at a high temperature. There is a problem that must be.

In order to solve these problems, there has been proposed an electrodeposition type resist in which a composition obtained by mixing a water-soluble or water-dispersible resin and a quinonediazide-based photosensitizer is an aqueous dispersion. For example, a composition obtained by mixing an alkali-soluble resin such as a phenol resin used for LSI production with a naphthoquinonediazidosulfonic acid ester of polyhydroxybenzophenone, and a phenol resin of the composition are used for electrodeposition for printed circuit boards. A composition using an acrylic resin or the like as a water-soluble or water-dispersible resin has been proposed because the type resist is not preferable from the viewpoint of water dispersibility and film properties. However, in these compositions, the stability of the aqueous dispersion is not sufficient and sedimentation is liable to occur.Since the photosensitive agent is partially present on the surface of the dispersed particles, the azide group is decomposed by contact of the basic substance with the azide group. And the photosensitivity decreases. Furthermore, when a sulfonic acid ester type photosensitizer is used,
It is difficult to obtain an electrodeposition resist bath solution having excellent operation stability over a long period of time, for example, the stability of the aqueous dispersion decreases due to hydrolysis of the sulfonic acid ester.

As a method for improving the stability of the aqueous dispersion,
Acrylic resin is obtained by using a comb-shaped acrylic resin obtained by copolymerizing a specific monomer having an acid group at the terminal of a relatively long chain length polyester or polyether and having a polymerizable unsaturated group at another terminal. By dispersing ion-forming groups in the molecule away from the hydrophobic resin skeleton to make it easier for the highly hydrophobic quinonediazide sensitizer to be present inside the resin particles dispersed in water, the stability of the aqueous dispersion is improved. It has been proposed to improve.

According to this method, the standing stability of the aqueous dispersion can be considerably improved, but it is still not enough to operate the bath stably for a long period of time. However, there is a problem that it is necessary to use the above-mentioned special monomer, or the production process is complicated and requires a long time.

Further, the monomer has a relatively high molecular weight, low copolymerizability with general acrylic ester-based monomers, etc., and remains unreacted in the resin, Prone to polymer. These unreacted monomers and homopolymers are apt to become water-soluble components in the aqueous dispersion, and can form a relatively stable aqueous dispersion in a stationary state, but are essential when performing electrodeposition coating. When the bath is circulated by the pump, which is a condition, the dispersed resin particles are liable to fuse with each other, agglomerates are formed in the bath, and adhere to the resist film to cause an abnormality in the coating film or a circulating system. There is still a problem as an electrodeposition resist such that the filter inside is easily clogged.

A mixture of a polymer containing a carboxyl group and a photosensitizer in which a quinonediazide-based photosensitive group is bonded to a polymer containing a phenolic hydroxyl group such as polyvinylphenol via a sulfonic ester bond is dispersed in water. Electrodeposited resists also do not have sufficient operational stability as electrodeposited resists, and the photosensitizer is obtained by using a polymer reaction, which has the above-described manufacturing problems.

Further, a composition using a block copolymer comprising a segment containing an ion-forming group and a segment not containing an ion-forming group as an acrylic resin, and combining this with an alkali-soluble phenol resin and a photosensitizer, can form a resist pattern having a good resolution. However, in order to obtain such an acrylic resin, an expensive polymerization initiator is required, and a complicated production process must be performed, which is economically disadvantageous.

Furthermore, the resist film formed by the electrodeposition coating method using these compositions has a low difference in solubility between exposed and unexposed portions in a developing solution, that is, a low contrast.
The drawback that the applicable developing condition width (temperature, time) is narrow, and the resistance to the etching solution is not enough, and when the copper to be etched on the circuit board is thick, the time may be increased or the temperature may be increased. Since the etching conditions become severe, the resist film is liable to be eroded and defects are likely to occur in circuit patterns and through holes.

[0016]

Means for Solving the Problems Accordingly, the present inventors have:
Excellent storage stability and circulation stability of the electrodeposition resist bath solution, high operation stability of the electrodeposition bath even at low turnover speed, high contrast as a resist film, excellent resistance to etching solution, and Intensive research to develop a positive-type photosensitive electrodeposition resist composition that can be manufactured without complicated and time-consuming reactions and complicated processes, and a highly reliable pattern forming method using the electrodeposition resist composition As a result, this time, a specific water-soluble or water-dispersible acrylic resin, a resin having a hydroxystyrene unit and a composition obtained by mixing a sulfonic ester of quinonediazidesulfonic acid and polyhydroxybenzophenone are mixed with a basic substance. By neutralizing a part or all of the carboxylic acid to form an aqueous dispersion, the above-mentioned problems can be solved at once. Composition that can be obtained, also found that it is possible to form a highly reliable pattern using the composition, and have completed the present invention.

Thus, according to the present invention, (A) a resin having a carboxyl group of 0.7 to 3.5 mol / kg resin and a hydroxyl group of 0.5 to 3.5 mol / kg resin having a number average molecular weight of 1
Acrylic resin of 000 to 100,000, formula (B)

[0018]

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A vinylphenol resin having a number average molecular weight of 1,000 to 25,000 containing 25% by weight or more of units represented by the following formula, and (C) polyhydroxybenzophenone and 1,2-naphthoquinonediazidosulfonic acid or A positive-type photosensitive anion electrodeposition resist comprising, as a main component, a water-dispersible resin composition obtained by neutralizing a mixture containing an esterified product with benzoquinonediazidesulfonic acid with a base and dispersing in water. And (a) a step of electrodepositing the above-described electrodeposition resist composition on the surface of a substrate or a metal having an electrically conductive film to form a positive photosensitive film; (b) the positive photosensitive film Exposing the coating through a pattern mask; (c) heating the exposed photosensitive coating; and (d) coating the exposed portion with an alkaline developer. A resist pattern forming method comprising the steps of: (a) removing a conductive pattern or an exposed conductive coating or metal etching; and (f) photosensitivity on the pattern. There is provided a method for forming a conductor pattern, which comprises a step of removing a coating.

In the electrodeposition resist composition of the present invention, the acrylic resin (A) is neutralized with a base to disperse the mixture of the above components (A), (B) and (C) in water, whereby the dispersion stabilizer is dispersed. And the hydrophobic component (B) and the more hydrophobic component (C) become the core components of the water-dispersed particles. The component (B) has an affinity for the components (A) and (C) and acts very effectively to form stable dispersed particles. When heated after exposure, it reacts with naphthoquinonediazide in the unexposed area, insolubilizes in a developing solution, and has the effect of dramatically increasing the resist pattern contrast and etching solution resistance.

Hereinafter, the electrodeposition resist composition of the present invention and a method of forming a pattern using the same will be described in more detail.

Acrylic resin (A) : The acrylic resin (A) used in the electrodeposition resist composition of the present invention has a carboxyl group content of 0.7 to 3.5 mol, preferably 1 to 2.2 mol per kg of the resin. 5 moles and 0.5 to 3.5 moles of hydroxyl groups,
Preferably it is 0.75 to 3.2 mol, more preferably 0.7 to 3.2 mol.
The number average molecular weight contained in the range of 8 to 3.0 mol is 10,
000-100,000, preferably 20,000-7
0000, more preferably 20,000-60,00
Acrylic resin in the range of 0.

The acrylic resin (A) can be prepared by, for example, polymerizing a carboxyl group-containing unsaturated monomer and a hydroxyl group-containing unsaturated monomer together with other copolymerizable monomers in a manner known per se, for example. It can be obtained by copolymerization in the presence of a catalyst and preferably in the presence of an organic solvent.

Examples of the carboxyl group-containing unsaturated monomer that can be used in this polymerization include (meth) acrylic acid,
Unsaturated carboxylic acids such as crotonic acid, itaconic acid, and maleic acid; polycarboxylic anhydrides such as the following hydroxyl-containing unsaturated monomers and phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and trimellitic anhydride; And a half esterified product thereof. Here, as the hydroxyl group-containing unsaturated monomer, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth)
C ₁ -C ₁₂ hydroxyalkyl esters of (meth) acrylic acid such as acrylates; unsaturated alcohols such as allyl alcohol;

Further, other copolymerizable monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n
-Butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate,
(Meth) such as 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate
C ₁ -C ₁₈ alkyl or cycloalkyl esters of acrylic acid; vinyl aromatic compounds such as styrene, α-methylstyrene, vinyltoluene, p-chlorostyrene, p-tert-butylstyrene; acrylamide, methacrylamide, N-methyl Polymerizable amides such as (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide; polymerizable nitriles such as acrylonitrile and methacrylonitrile; vinyl acetate, vinyl propionate, vinyl lactate; Vinyl butyrate,
Vinyl esters such as vinyl isobutyrate, vinyl caproate, vinyl isocaproate, vinyl pivalate, vinyl caprate, and veova monomer (manufactured by Ciel Chemical); propenyl esters such as isopropenyl acetate and isopropenyl propionate;

[0026]

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[0027] (wherein, n is an integer of 1 to 9, R ₁ and R ₂ each represents a hydrogen atom or a methyl group, R ₃
To R ₇ each represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a benzyl group or a halogen atom).

On the other hand, the organic solvent used in the polymerization reaction is not particularly limited as long as it can dissolve the acrylic resin to be produced. For example, a C ₁ -C ₈ linear or branched alkyl alcohol; C ₁ -C ₈ alkyl alcohols containing aromatic rings such as alcohols; mono- or diethers of C ₁ -C ₈ linear or branched alcohols with glycols such as ethylene glycol, propylene glycol, butylene glycol or dimers thereof ; esters of carboxylic acids of the monohydroxy compound and the C ₁ -C _4; ethylene glycol, propylene glycol, glycols or mono or diether of its dimer and phenol or alkyl-substituted phenols of C ₁ -C _12, such as butylene glycol The above glycols or dimers thereof; Ketones such as ton, methyl ethyl ketone, methyl butyl ketone, dibutyl ketone, cyclohexanone, isophorone; carbonates such as ethylene carbonate and propylene carbonate; pyrrolidones such as N-methylpyrrolidone; aromatic hydrocarbons such as toluene, xylene and ethylene benzene Compounds and the like can be used alone or as a mixture. Among these organic solvents, an organic solvent system which is water-soluble in itself or which is 50% by weight or more in the organic solvent is particularly preferable.

The proportion of the monomer used is adjusted so that the resulting acrylic resin (A) has a carboxyl group content and a hydroxyl group content within the above ranges.

The acrylic resin (A) has a carboxyl group content of less than 0.7 mol / kg resin and / or a hydroxyl group content of 0.7 mol / kg resin.
If the amount is less than 5 mol / kg resin, the water dispersion stabilizing ability of the resin is insufficient, and the stability of the resulting dispersion is likely to be reduced. On the other hand, when the carboxyl group content exceeds 3.5 mol / kg resin, on the contrary, the water solubility of the resin itself becomes too high,
The ability to hold the components (B) and (C) as the core component of the dispersed particles is reduced, and the amount of the water-soluble component in the dispersion is increased. is there. On the other hand, when the hydroxyl group content exceeds 3.5 mol / kg resin, the swelling property of the unexposed portion becomes high when developing the resist film, so that the resolution is reduced, and the etching solution resistance of the formed resist pattern is reduced. Easy to do. Further, when the molecular weight of the acrylic resin (A) is lower than 10,000, the stability of the dispersion to be formed is reduced, or the physical properties of the formed resist film are reduced, so that the resist film is easily damaged during etching. . On the other hand, when the molecular weight exceeds 100,000, the viscosity becomes high, and it becomes difficult to synthesize the resin and disperse it in water, which is not preferable.

Vinylphenol resin (B) : The vinylphenol resin (B) used in the electrodeposition resist composition of the present invention has the formula

[0032]

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25% by weight or more, preferably 30 to 100% by weight, of the hydroxystyrene unit represented by
More preferably, it contains 40 to 100% by weight and has a number average molecular weight of 1,000 to 25,000, preferably 2,500.
0-20,000, more preferably 3,500-17,
000.

The resin (B) includes, for example, a homopolymer of hydroxystyrene such as p-hydroxystyrene, and a copolymer of hydroxystyrene and another copolymerizable monomer. As other copolymerizable monomers that can be used here, other copolymerizable monomers similar to those exemplified for the production of the acrylic resin (A) can be used.

In the case where the above copolymer is used as the resin (B), if the content of hydroxystyrene units in the resin is less than 25% by weight, generally, the resist film to be formed is exposed to unexposed portions by heating after exposure. The desired effect is difficult to obtain due to insufficient insolubilization reaction. Further, when the number average molecular weight of the resin (B) is lower than 1,000, the physical properties of the formed resist film are reduced, the adhesion to the substrate is reduced, and the resist film is liable to be damaged during etching. When the average molecular weight exceeds 25,000, solubility in a solvent and compatibility with other components tend to decrease.

[0036]Quinonediazidesulfonic acid ester
(C): Photosensitive composition in the electrodeposition resist composition of the present invention
Quinonediazide sulfonic acid ester used as a component
(C) is polyhydroxybenzophenone and 1,2-na
Futoquinone diazide sulfonic acid or benzoquinone diazi
It is an esterified product with dosulfonic acid.

The polyhydroxybenzophenone used to form this ester has the following formula

[0038]

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In the formula, m and n are each an integer of 0 to 3, provided that the sum of m + n is 1 to 6, and specifically includes, for example, 2,3,4- Trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone and the like.

On the other hand, 1,2-naphthoquinonediazidesulfonic acid and benzoquinonediazidesulfonic acid which are esterified with polyhydroxybenzophenone have the following formulas, respectively.

[0041]

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The following are included. Specifically,
1,2-naphthoquinonediazide-5-sulfonic acid, 1,2
-Naphthoquinonediazide-4-sulfonic acid, 1,2-benzoquinonediazide-4-sulfonic acid, and the like.

The above polyhydroxybenzophenone and 1,1
The esterification reaction with 2-quinonediazidesulfonic acid can be carried out by a method known per se, for example, by reacting polyhydroxybenzophenone with 1,2-quinonediazidesulfonic acid or a halide thereof (eg, chloride). The reaction ratio of the two is not particularly limited, but generally, it is preferable to react 1,2-quinonediazidesulfonic acids at a ratio of 1 to q molecules with respect to the number q of hydroxyl groups in the polyhydroxybenzophenone. It is. These polyhydroxybenzophenones and quinonediazide compounds may be used alone or in combination of two or more.

Electrodeposited resist composition : The electrodeposited resist composition of the present invention comprises the above-mentioned three components of the acrylic resin (A), vinylphenol resin (B) and quinonediazide sulfonic acid ester (C) as essential components. It contains.

The mixing ratio of these three components in the composition of the present invention is not strictly limited, and can be changed according to the use of the composition, the type of these three components, and the like.

The vinylphenol resin (B) comprises (A)
The quinonediazide sulfone is preferably present in an amount of 5 to 550 parts by weight, particularly 5 to 450 parts by weight, more preferably 25 to 350 parts by weight, per 1000 parts by weight of the total of the three components (B) and (C). The acid ester (C)
It is preferably present in the range of 15 to 450 parts by weight, particularly 15 to 350 parts by weight, more preferably 25 to 250 parts by weight, per 1000 parts by weight of the total of the three components (A), (B) and (C). .

In the composition of the present invention, if the content of the carboxyl group is too small, the aqueous dispersion tends to be unstable. On the other hand, if the content is too large, the coulomb yield when the composition is electrodeposited. , And abnormalities such as pinholes are likely to occur on the painted surface. Therefore, the content of the carboxyl group in the composition of the present invention is 3 (A), (B) and (C).
Generally, from 0.33 to 3.3 per 1000 g of the total amount of the components
Conveniently it is in the range of from 0.5 to 2.5 mol, more preferably from 0.6 to 2.0 mol.

The total of the carboxyl group and the non-phenolic hydroxyl group is generally from 0.6 to 6 mol, particularly preferably from 0.6 to 6 mol per 1,000 g of the total of the three components (A), (B) and (C).
The presence in the range of 6 to 4.5 moles, more particularly 0.6 to 3.0 moles, depends on the dissolution rate of the exposed portion of the resist film in the developing solution, the contrast and resolution of the formed image, and the like. Is preferred.

Here, the term "non-phenolic hydroxyl group" refers to a hydroxyl group not directly bonded to an aromatic ring.

The electrodeposition resist composition of the present invention is obtained by neutralizing a mixture containing the above-mentioned acrylic resin (A), vinylphenol resin (B) and quinonediazidesulfonic acid ester (C) in the above ratio with a base. It can be prepared by dispersing in water. The base that can be used for the neutralization is not particularly limited as long as it does not adversely affect the electrodeposition operation, and can be selected from a wide range of bases, for example, triethylamine, monoethanol, diethanolamine, diisopropylamine, and dimethylamine. Examples include aminoethanol, morpholine, ammonia, sodium hydroxide and the like. The degree of neutralization is usually 25-100%, especially 35-95% of the carboxyl groups present in the mixture.
Is preferably neutralized.

As a method of dispersing in water, for example,
A method of dispersing a mixed neutralized product of the components (A), (B) and (C) in water; a method of adding water to the mixed neutralized product and dispersing the same; the components (A), (B) and (C) A method of adding and dispersing the mixture of the above in water containing a base for neutralization; and a method of adding and dispersing water containing a base to the mixture. The aqueous dispersion thus obtained has a solids content of 0.5.
Stability stability within a wide solids content range of 5-40% by weight,
It has an excellent property of good circulation stability.

The composition of the present invention may contain an organic solvent and a solvent as necessary to dissolve the resin and the photosensitive agent, or to adjust the film thickness and flowability of a film obtained by electrodeposition coating. Can be blended. The organic solvent used is not particularly limited, but lower alcohols such as ethanol, propanol and butanol; (di) ethylene glycol,
(Di) Monoethers of glycols such as propylene glycol with methanol, ethanol, propanol, butanol and the like; diethers of the glycols and the alcohols; hydrophilic organic solvents such as methyl ethyl ketone, tetrahydrofuran and dimethylformamide, or hexyl alcohol Octyl alcohol, higher alcohols such as benzyl alcohol, etc .; monoethers of the glycols with hexanol, octanol, phenol; diethers of the glycols with hexyl alcohol, octyl alcohol, benzyl alcohol; methyl isobutyl ketone, cyclohexanone, isophorone, etc. Ketones; and hydrophobic organic solvents such as aromatic hydrocarbons such as toluene, xylene and ethylbenzene. The hydrophilic organic solvent is particularly effective for dissolving the resin and the photosensitive agent and adjusting the flowability, and is usually 200 parts by weight or less based on 100 parts by weight of the total of the three components (A), (B) and (C). , Especially 1
It is preferable to use within a range of 25 parts by weight or less. Hydrophobic organic solvents are particularly effective in adjusting the film thickness.
It is preferable to use 50 parts by weight or less, especially 30 parts by weight or less based on 100 parts by weight of the total of the three components (A), (B) and (C).

The electrodeposition resist composition of the present invention may further contain, if necessary, a surfactant, a flow control agent, an additive such as a chelating agent, and a coloring agent such as a pigment or a dye. Can be.

The solid concentration of the electrodeposition resist composition of the present invention is not particularly limited, but is usually in the range of 3 to 40% by weight. As the electrodeposition coating bath, those having a solid content of 3 to 20% are generally used. However, in order to keep the electrodeposition coating bath at a constant concentration, the solid content of the electrodeposition coating bath is usually 1.5 times. It is necessary to prepare an aqueous dispersion having a solid content of about 2.0 times higher, and it is important that the stability of the aqueous dispersion is good in the above range in order to obtain excellent operation stability.

The thus obtained electrodeposition resist composition of the present invention provides an electrodeposition coating bath which is easy to produce, is economically excellent, and has excellent operation stability.

The positive photosensitive electrodeposition resist composition of the present invention is extremely useful for forming a resist pattern or a conductor pattern, and the pattern can be formed, for example, as follows.

Pattern formation : First, an electrodeposition coating bath prepared using the composition of the present invention (bath solid concentration: 3 to 20)
%), A circuit board having a conductive coating such as copper foil or a metal board such as copper foil, copper alloy foil, or stainless steel foil is immersed as an anode, and a constant voltage direct current or constant An electrodeposition resist composition is electrodeposited by applying a direct current having a current density. As a method for applying a DC current, a method combining the above-described application methods, a method combining a method for controlling an increase in voltage or current density at the beginning of energization, or the like can be used.

In the constant voltage method, the applied voltage is usually 10 to 300
v, and the applied current density can be usually in the range of 10 to 200 mA / dm ^{2 in} the constant current method. The energization time is usually about 20 seconds to about 10 minutes, whereby a positive photosensitive film is formed on the substrate. The film thickness can be generally in the range of 2 to 50 μm, preferably 3 to 20 μm in dry film thickness.

Next, after the electrodeposition coating, the object to be coated is pulled up from the electrodeposition bath, washed with water, drained and dried with hot air or the like. The surface of the positive-type photosensitive electrodeposited film formed as described above is exposed to active light such as ultraviolet rays through a pattern mask (for example, a photo positive).

The actinic rays for exposure are usually 3,0
Those having a wavelength of 00 to 4,500 ° can be used. These light sources include, for example, sunlight, mercury lamps, xenon lamps, arc lamps and the like.

After exposure to actinic light, the photosensitive coating is usually treated at about 100 ° C. or higher, preferably about 120 ° C. to about 180 ° C.
Heat at the above temperature for about 1 to 60 minutes. As a result, the degree of insolubilization of the unexposed portion with respect to the developing solution is increased, and the contrast with the exposed portion is increased. As a result, the range of conditions for development can be widened, and the etching solution resistance can be increased.
Next, a developing process for forming a resist pattern by removing the photosensitive film on the exposed portion is performed. The development treatment can be performed using an alkaline developer, for example, by spraying dilute alkaline water onto the coating film surface to wash (remove) the exposed portion of the coating film. As the diluted alkaline water, for example, alkaline substances such as sodium hydroxide, potassium hydroxide, sodium metasilicate, potassium metasilicate, sodium carbonate, ammonia, and tetraethylammonium hydroxide are dissolved in water to adjust the pH to 9 to 13.
An aqueous solution adjusted within the range described above can be used.

By this developing treatment, a resist pattern can be formed on the surface of the substrate or metal.

The resist pattern thus formed can be used for forming a conductor pattern. That is, a conductive pattern can also be formed by removing the conductive film or metal exposed by the above-mentioned development processing by etching, and removing the photosensitive film on the pattern.

The exposed conductive film (non-circuit portion), which is an etching pattern formed on the substrate by the above-mentioned development processing, is formed of, for example, an acidic etching solution such as a ferric chloride solution or an ammonia / ammonium chloride system. It can be removed by a normal etching process using an alkali etching solution or the like. Thereafter, a conductive pattern, for example, a printed wiring board can be manufactured by removing the photosensitive film which is an unexposed film on the circuit pattern. The unexposed coating film is, for example, a cellosolve-based solvent such as ethyl cellosolve or ethyl cellosolve acetate; an aromatic hydrocarbon-based solvent such as toluene or xylene;
It can be removed by a ketone-based solvent such as methyl ethyl ketone or methyl isobutyl ketone; an acetate-based solvent such as ethyl acetate or butyl acetate; or a strong alkaline aqueous solution such as sodium hydroxide.

In the resist pattern thus formed, the unexposed portion of the resist film has a crosslinked structure.
Compared to conventional positive electrodeposited photoresist, the unexposed area has higher resistance to developing solution and etching solution, so that a wide range of allowable conditions in developing operation and a high-contrast resist pattern can be obtained. Sometimes, the resist film is hardly damaged, and the accuracy of the formed pattern is excellent. Therefore, in the manufacture of a printed circuit board having a fine pattern, metal fine processing, and the like, an image forming process can be easily controlled and an image with extremely high accuracy can be obtained.

Further, the electrodeposition solution and the high-concentration solution used for replenishing the electrodeposition solution have extremely high stability, and therefore are industrially extremely useful in that excellent operation stability of the electrodeposition bath can be obtained.

[0067]

The present invention will be described more specifically with reference to the following examples.

Production Example 1 : Production of acrylic resin (A) -1 n-butyl methacrylate 223 parts by weight n-butyl acrylate 241 parts by weight 2-hydroxyethyl acrylate 207 parts by weight Styrene 200 parts by weight Acrylic acid 129 parts by weight t-butyl 10 parts by weight of peroxy-2-ethylhexanoate 1010 parts by weight of the above mixture was dropped into 502 parts by weight of propylene glycol monomethyl ether which had been heated and stirred at 120 ° C. under a nitrogen stream in a reaction vessel over 4 hours. Then, it was kept at the same temperature for 1 hour. Then, t-butyl peroxy-2-ethylhexanoate 5
Parts by weight of propylene glycol monomethyl ether 15
20 parts by weight of the solution dissolved in parts by weight was added dropwise over 1 hour, and further kept at 120 ° C. for 1 hour and then cooled to obtain a resin solution (A) -1 having a solid content of about 66% by weight. The obtained resin (solid content) had a number average molecular weight (by gel permeation chromatography, hereinafter the same) of about 40,000.
0, a carboxyl group content of 1.80 mol / kg resin and a hydroxyl group content of 1.80 mol / kg resin.

Production Example 2 : Production of acrylic resin (A) -2 150 parts by weight of methyl methacrylate 365 parts by weight of n-butyl acrylate 255 parts by weight of styrene 155 parts by weight of styrene 75 parts by weight of acrylic acid Azobisisobuty 7.5 parts by weight of lonitrile 1007.5 parts by weight of the above mixture were heated to 90 ° C. in a reaction vessel under a nitrogen stream at 90 ° C. and stirred and stirred for propylene glycol monomethyl ether / ethylene glycol monobutyl ether 1/1/1 (weight ratio) 651. The mixture was added dropwise over 3 hours in the weight part, and was kept at the same temperature for 2 hours. Then
18 parts by weight of a solution obtained by dissolving 3 parts by weight of azobisisobutyronitrile in 15 parts by weight of propylene glycol monomethyl ether were added dropwise thereto over 1 hour, and 90 parts of
After holding at 2 ° C. for 2 hours, the mixture was cooled to obtain a resin solution (A) -2 having a solid content of about 60% by weight. Obtained resin (solid content)
Was a number average molecular weight of about 53,000, a carboxyl group content of 1.04 mol / kg resin and a hydroxyl group content of 2.20 mol / kg resin.

Production Example 3 : Production of acrylic resin (A) -3 150 parts by weight of ethyl acrylate 350 parts by weight of n-butyl acrylate 115 parts by weight of 2-hydroxyethyl methacrylate 185 parts by weight of styrene 200 parts by weight of methacrylic acid t-butyl 15 parts by weight of peroxy-2-ethylhexanoate 1015 parts by weight of the above mixture was dropped into 646 parts by weight of ethylene glycol monobutyl ether, which was heated and stirred at 120 ° C. under a nitrogen stream in a reaction vessel over 3 hours. Then, it was kept at the same temperature for 1 hour. Then, 20 parts by weight of a solution obtained by dissolving 5 parts by weight of t-butylperoxy-2-ethylhexanoate in 15 parts by weight of propylene glycol monomethyl ether was added dropwise over 1 hour, and further added at 120 ° C. for 2 hours. After holding, the mixture was cooled to obtain a resin solution (A) -3 having a solid content of about 60% by weight. The resulting resin (solid content) had a number average molecular weight of about 28,000, a carboxyl group content of 2.33 mol / kg resin and a hydroxyl group content of 0.88 mol / kg resin.

Production Example 4 : Production of Acrylic Resin (A) -4 100 parts by weight of methyl methacrylate 200 parts by weight of n-butyl acrylate 330 parts by weight of 2-hydroxyethyl acrylate 170 parts by weight of styrene 200 parts by weight of acrylic acid t-butyl par Oxy-2-ethylhexanoate 15 parts by weight

1015 parts by weight of the above mixture was added dropwise over 3 hours to 646 parts by weight of ethylene glycol monobutyl ether which had been heated and stirred at 120 ° C. under a nitrogen stream in a reaction vessel, and further maintained at the same temperature for 1 hour. did. Then, 20 parts by weight of a solution obtained by dissolving 5 parts by weight of t-butylperoxy-2-ethylhexanoate in 15 parts by weight of propylene glycol monomethyl ether was added dropwise over 1 hour, and further added at 120 ° C. for 2 hours. After holding, the mixture was cooled to obtain a resin solution (A) -4 having a solid content of about 60% by weight. The obtained resin (solid content) has a number average molecular weight of about 32,
000, a carboxyl group content of 2.78 mol / kg resin and a hydroxyl group content of 2.84 mol / kg resin.

Examples 1 to 12 and Comparative Example 1 Based on the formulations shown in Table 1 below, raw materials other than deionized water were mixed, neutralized with a base, and dissolved uniformly. Put deionized water in a container
The mixture was gradually added to water stirred at 2,000 to 3,000 rpm, and after the addition was completed, the mixture was further stirred at 500 rpm for 20 minutes to obtain an aqueous dispersion.

[0074]

[Table 1]

[0075]

[Table 2]

[0076]

[Table 3]

Test Example 1 The aqueous dispersions of Examples 1 to 12 and Comparative Example 1 were placed in a closed container, left at 35 ° C. for 1 hour and 90 days, and the state of the contents was observed. Table 2 shows the results.

[0078]

[Table 4]

Test Example 2 The aqueous dispersions of Examples 1 to 12 and Comparative Example 1 were diluted with deionized water to a solid content of 8% to prepare an electrodeposition bath solution. Each was compared in the same manner as in Test Example 1. Table 3 shows the results.

[0080]

[Table 5]

Further, each of the electrodeposition bath solutions was
of a centrifugal pump with a mechanical seal and a cartridge filter having a pore size of 10 μm, and keeping the bath solution at 30 ° C. at a circulation rate of 10 turns / hr.
Stirred for 0 days.

No abnormality was observed in the bath liquids of Examples 1 to 12, but in Comparative Example 1, clogging of the filter became noticeable from around 15 days after the start of stirring, and circulation became impossible in 60 days.

Test Example 3 Copper-plated through-holes having a diameter of 1.0 to 0.3 mmφ and a copper thickness of 45 μm and 7 mm respectively
Electrodeposition coating was performed under the following conditions in an electrodeposition bath having the composition shown in Table 1 above using two 5 μm glass fiber reinforced epoxy resin copper-clad laminates as anodes. Table 4 shows the results.

[0084]

[Table 6]

Bath temperature: 27 ° C. Stirring: 5 turns over / hr The substrate was washed with water after electrodeposition coating, drained and dried at 80 ° C. for 10 minutes.

Abnormal precipitation: bumps and pinholes are observed on the coated surface.

Test Example 4 Regarding Examples 1 to 12 and Comparative Example 1 obtained in Test Example 3, the through-hole portions were shielded from light, and the line / space was changed from 30/30 μm to 10 μm in portions other than the through-hole portions.
100/100 μm in m increments, 25 or more
After a photomask having a test pattern made of a polyethylene terephthalate film having a line pattern of 200/200 μm in increments of μm was brought into close contact with each substrate, irradiation was performed with an ultrahigh pressure mercury lamp. Development etching and the like were performed under the conditions shown in Table 5, and the performance comparison results are shown in Table 5.

[0088]

[Table 7]

[0089]

[Table 8]

Further, the results of the same treatments as in Examples 1 to 12 except that the heat treatment after exposure was not performed are shown in Table 6 as Comparative Examples 2 to 13.

[0091]

[Table 9]

[0092]

[Table 10]

In Tables 5 and 6, exposure amount: 200 mj / cm ² Developing solution 1: Using 0.7% aqueous sodium carbonate solution 2: Using 1.5% aqueous sodium metasilicate solution Resolution: Resist pattern Narrowest L / S with L / S reproducibility of 5% or less Developing conditions: Examples 1 to 12 30 ° C. for 75 seconds and 40 ° C. for 180 seconds Comparative Example 1 30 ° C. for 75 seconds 2 to 13 30 ° C. 75 seconds and 35 ° C for 120 seconds

The development conditions in Tables 5 and 6 indicate the range of development conditions that do not cause defects (cuts, distortions, and peelings) in the resist pattern.

Sensitivity: The development conditions are the same as for the resolution. Exposure amount (mj / c) required to obtain 5 steps of step tablets (21 steps manufactured by Eastman Kodak Company)
m ² ).

Etching property: Exposure amount: 200 mj / cm ² Etching solution: Using cupric chloride-based etching solution Etching condition: Temperature: 50 ° C. Time 1.5 times of the shortest time required for completely etching a substrate without a resist film Double pattern: 100 μm pattern etching reduced width μm Through hole: O No abnormality in copper plating inside through hole VS There is conduction that copper plating inside through hole is slightly affected S Copper is partially plated inside through hole Corrosion, non-conducting through-holes occur within 3% P Copper plating inside through-holes is corroded, non-conducting through-holes occur 10% or more. In each of the samples of Examples and Comparative Examples, 50 ° C.
By spraying 1% aqueous sodium hydroxide solution
Within 0 seconds, the resist film including the inside of the through hole could be peeled off.

Test Example 5 Using the electrodeposition bath solution of Example 5, a resist film was formed on both sides of a 200 μm-thick conductive foil under exactly the same conditions as in Test Example 3, and a line was formed on the surface so as to be a mirror surface. / Space 60 /
A photomask made of a polyethylene terephthalate film having a pattern of 60 microns was brought into close contact with it and exposed to 200 mj / cm ^{2 with} an ultra-high pressure mercury lamp. After that, development, etching, and resist film peeling were performed in exactly the same manner as in the etching test of Test Example 4. A good punching pattern having a line width reduction rate of an image within 10% was obtained.

[0098]

The electrodeposition resist composition of the present invention comprises:
By mixing the components (A), (B) and (C) at a specific ratio, a positive photosensitive anion electrodeposition resist having excellent performance can be easily produced at a low production cost.

Further, according to the pattern forming method of the present invention, it is possible to form a resist film pattern having extremely excellent resistance to an etching solution without deteriorating the resolution.
An etching pattern can be obtained without damaging the shape of the conductive circuit formed on the circuit board having a large copper thickness and the copper plating in the through hole.

Further, the electrodeposition resist composition of the present invention comprises:
Utilizing this extremely high etchant resistance, it can be used as a metal punching resist for TAB or lead frame having a high-density pattern.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI H01L 21/027 H05K 3/06 H H05K 3/06 H01L 21/30 502R (72) Inventor Hideo Kogure 4-chome Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture No. 17-1 Kansai Paint Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) C09D 133/00

Claims (3)

(57) [Claims] (A) A resin having a carboxyl group of 0.7 to 3.5 mol / kg resin and a hydroxyl group of 0.5 to 3.5 mol / kg and having a number average molecular weight of 10,000 to 100,000. Acrylic resin, formula (B) A vinylphenol resin having a number average molecular weight of 1,000 to 25,000 containing 25% by weight or more of units represented by the following formula: and (C) polyhydroxybenzophenone and 1,2-naphthoquinonediazidesulfonic acid or benzoquinonediazidesulfonic acid Containing an ester with an acid, and (A) +
Component (B) is contained in an amount of 5 to 550 parts by weight, component (C) is added in an amount of 15 to 450 parts by weight, and component (A) + (B) + ( A mixture containing 0.33-3.3 mol of carboxyl groups and 0.6-6.0 mol of carboxyl groups and non-phenolic hydroxyl groups in total per 1,000 g of the total of C) is neutralized with a base and dispersed in water. A positive photosensitive anion electrodeposition resist composition comprising a water-dispersible resin composition obtained as a main component. 2. (a) a step of electrodepositing the electrodeposition resist composition according to claim 1 on a surface of a substrate or a metal having an electrically conductive film to form a positive photosensitive film; Exposing the positive photosensitive film through a pattern mask; (c) heating the exposed photosensitive film; and (d) forming a pattern by removing the exposed portion of the film with an alkaline developer. A method for forming a resist pattern, comprising: 3. A step of (a) electrodepositing the electrodeposition resist composition of claim 1 on a surface of a substrate or a metal having an electrically conductive film to form a positive photosensitive film; Exposing the positive photosensitive film through a pattern mask; (c) heating the exposed photosensitive film; and (d) forming a pattern by removing the exposed portion of the film with an alkaline developer. (E) a step of removing the exposed conductive film or metal by etching; and (f) a step of removing the photosensitive film on the pattern.