JP3030102B2 - Coating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an etched product, and more particularly to a method for curing a coating film using a visible light laser and removing a non-exposed portion film by a development process. Further, the present invention relates to a method of forming an etching resist excellent in etching resistance, which can obtain a processed product or a circuit pattern which forms a good etching pattern by performing an etching treatment after exposure to visible light and / or ultraviolet light.

[0002]

2. Description of the Related Art A photosensitive composition is a photoresist, a lithographic or letterpress plate-making material, a PS for offset printing.
It is widely used in various applications such as plates, information recording materials, and relief image forming materials. Many of these photosensitive compositions are sensitive to ultraviolet light, and their sensitivity is generally tens to hundreds of mJ /
cm ² , there is a problem that a high-output light source is required, and energy conversion efficiency for recording is poor.
On the other hand, there is a method of forming an image by directly drawing using a high energy density light source such as a laser.
This method has the advantage that not only the energy conversion efficiency is improved but also that the image forming process can be greatly simplified. In this case, it is more advantageous to use a visible laser capable of obtaining a stable oscillation line in terms of life and intensity than using an ultraviolet laser as a scanning exposure light source for direct writing.

[0003] For this reason, it has been desired to develop a visible light-sensitive composition having a sensitivity capable of performing scanning exposure with a visible laser, and Ar ⁺ having a stable oscillation line in the visible region having a wavelength of 488 nm. Many visible light-sensitive compositions having high sensitivity to lasers have been proposed (for example, JP-A-62-318).
No. 48, JP-A-61-233736, JP-A-60-221403, Abstracts of the 1st Annual Conference of the Printed Circuit Society of Japan, 91 pages, Printed Circuit World Conv
ention IV. technical paper 22-2).

[0004] These visible light-sensitive compositions are in the form of a film or liquid, but they have the following disadvantages.

Since the visible light-sensitive film molded into a film has a thickness of several tens of μm, an image formed by light irradiation is not clear, and the film can be uniformly adhered to the conductor surface without gaps. It is difficult to use the film effectively (there is a loss) and the product is expensive.

On the other hand, the liquid visible light-sensitive composition has good adhesion to the conductor surface, but has a high resolution etching resist film excellent in visible light sensitivity to obtain a fine image pattern. What can be formed has not been obtained so far.

[0007] The present inventors have previously solved the problem of the visible light sensitivity of such a liquid photosensitive composition, and have described an etching-processed product, that is, a conductor surface such as a laminated plate or a metal plate on which a metal foil is adhered. A method of forming an etching resist film which can be uniformly coated with a thickness of 30 μm or less, has excellent visible light sensitivity and can form a high-resolution image has been proposed (Japanese Patent Application No. 1-223855). Book). This photocurable etching resist is exposed to actinic rays,
It is developed with a weak alkali or weak acid, washed with water, and dried to form a resist film, and a metal is etched with an acid or alkali to obtain an image pattern.

However, in recent years, the number of cases in which a variety of etching products and circuit patterns are produced in a large variety and in small quantities has increased.
In order to rationalize the manufacturing process, the visible light laser direct drawing method has been receiving more and more attention. However, when performing pattern exposure with this visible light laser, the resist film to be scanned at a high speed is required. Insufficient curing makes it difficult to etch a thick metal plate, and the circuit pattern is poor in accuracy. There are drawbacks such as difficulty in etching a fine pattern having a width of 150 μm or less.

On the other hand, if the scanning speed is reduced to increase the amount of exposure, a fine pattern etching process can be performed. However, the scanning time becomes longer, the productivity is deteriorated, and it is not suitable for industrial use. Also, even if the exposure amount is too large, it is difficult to obtain a fine pattern. Currently available industrially
Due to the capability of the drawing apparatus, for industrial use,
The amount of exposure for forming a resist film that resists etching needs to be about 5 mJ / cm ² or less.

[0010]

DISCLOSURE OF THE INVENTION The present inventors have developed an industrially useful metal plate or metal foil for fine processing by a visible light laser direct drawing method which does not have the above-mentioned problems. As a result of intensive studies on the method of forming an etching resist film on the laminate, a liquid resist was applied to a metal plate or a metal foil-clad laminate, dried, exposed by a visible light laser, developed, washed with water, and dried. Thereafter, it was found that the precision of the etching circuit pattern of a thick metal plate was significantly improved by further short-time exposure with visible light and / or ultraviolet light, and the present invention was completed.

Thus, according to the present invention, a liquid photosensitive composition containing a photocurable resin containing a photosensitive group capable of being crosslinked or polymerized by irradiation with visible light and an ionic group and a photopolymerization initiator was coated. There is provided a method for forming an etching resist film, which comprises exposing a coated plate with a visible light laser, developing the coated plate, and further exposing the coated plate to visible light and / or ultraviolet light.

According to the method of the present invention, a highly productive etching resist film particularly suitable for fine etching of a thick metal plate and forming a fine circuit pattern on a metal foil-clad laminate. Can be obtained.

Hereinafter, the present invention will be described in more detail.

In the present invention, the photocurable resin containing a photosensitive group which can be crosslinked or polymerized by light irradiation and an ionic group includes a polymerizable unsaturated resin containing an anionic or cationic ionic group. Included. There is no particular limitation on these resins, but as typical ones,
For example, an acrylic resin, a polyester resin, a urethane resin, an epoxy resin, a polybutadiene resin, or the like containing a polymerizable unsaturated group in a side chain or a main chain can be used. The content of unsaturated groups in these resins is generally suitable as an unsaturated equivalent in the range of 150 to 3,000, and the resin generally has a number average molecular weight of 300 or more, preferably in the range of 1,000 to 30,000. be able to. Further, the content of the ionic group is an amount necessary for removing an unexposed portion by dissolving or swelling with a developer, and generally 0.2.
程度 5.5 mol / kg resin.

[0015] These resins are generally volatile solvents and / or
Alternatively, one or more polymerizable unsaturated group-containing compounds are added to the molecule, and a photopolymerization initiator, a polymerizable unsaturated resin other than the above-described polymerizable unsaturated resin, a saturated resin, and if necessary, fluidity control. A liquid photosensitive composition is obtained by mixing with additives such as an agent, an extender, a coloring pigment, and a dye. Furthermore, by neutralizing a part or all of the ionic groups in the photocurable resin with an acid or an alkali, the photosensitive composition of the present invention can be used in the form of an aqueous solution or an aqueous dispersion.

The liquid photosensitive composition according to the present invention comprises a polymerizable unsaturated group-containing compound, for example, a polyester acrylate containing an ethylenically unsaturated group, a polyurethane, in addition to the polymerizable unsaturated resin described above as a resin component. Resins, epoxy resins, acrylic resins, etc .; saturated resins, for example, polyester resins, polyurethane resins, epoxy resins, acrylic resins, etc .; oligomers, for example, diethylene glycol di (meth) acrylate; ethylenically unsaturated compounds, for example, (meth) ) Acrylic esters and the like may be blended in an amount of 100 parts by weight or less, preferably 50 parts by weight or less based on 100 parts by weight of the polymerizable unsaturated resin, so that the coating film performance may be appropriately adjusted. It is possible.

Examples of the volatile solvent include hydrophobic solvents such as petroleum solvents such as toluene and xylene; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate and butyl acetate; 2-ethylhexyl alcohol and the like. Alcohols; and the like. Also, a hydrophilic solvent such as isopropanol, n
-Butanol, t-butanol, methoxyethanol,
Ethoxyethanol, butoxyethanol, diethylene glycol, methyl ether, dioxane, tetrahydrofuran and the like can be used. The type of the solvent is not limited to the examples given here, and can be selected from a wide range as long as the resin additive or the like can be stably dissolved or dispersed.

When an aqueous solution or aqueous dispersion for electrodeposition coating described below is produced, the amount of the hydrophilic solvent is usually 300 parts by weight or less and the hydrophobic solvent is 200 parts by weight or less based on 100 parts by weight of the resin component. It is preferred to use.

In the present invention, a photopolymerization initiator is indispensable for performing visible light curing. A visible light polymerization initiator alone, a combination of a visible light polymerization initiator and a sensitizer, or a photo polymerization initiator obtained by combining a radical generator and a sensitizer can be used. Specific examples thereof include titanocene compounds, combinations of titanocene compounds with coumarin derivatives or ketocoumarin derivatives, combinations of organic peroxides with coumarin derivatives or ketocoumarin derivatives, bisimidazoles and imida N-vinylsuccinate and thiol compounds. A combination of a diphenyliodonium salt with a merocyanine dye or a thioxanthene dye, a combination of N-phenylglycine with a ketocoumarin derivative, imidazo-
Combination of dimer and acridine dye or aryl ketone, 2,4,6-tris (trichloromethyl) -5-
Triazine, 3-phenyl-5-isoxazolone, 2
-Combinations of mercaptobenzimidazole and the like with merocyanine dyes and aromatic ketones.

When the exposure after development is carried out with ultraviolet rays, an ultraviolet polymerization initiator can be used together with the visible light polymerization initiator in order to carry out the post-exposure curing efficiently. Specific examples thereof include benzoin, benzoin methyl ether, benzoin ethyl ether, benzyl, diphenyl disulphide, tetramethylthiuram monosulfide, diacetyl, eosine, thionin,
Michler's ketone, anthraquinone, chloranthraquinone, methylanthraquinone, α-hydroxyisobutylphenone, p-isopropyl-α-hydroxyisobutylphenone, α, α'-dichloro-4-phenoxyacetophenone, 1-hydroxy1- Cyclohexylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, methylbenzoylformate, 2-methyl-
1- [4- (methylthio) phenyl] -2-morpholino-propene, thioxanthone, benzophenone and the like.

The above-mentioned visible light polymerization initiator, radical generator, sensitizer and ultraviolet polymerization initiator are generally used in an amount of 0.1 to 1 based on 100 parts by weight of the resin component (solid content).
A range of 0 parts by weight is suitable. Further, when the photosensitive composition of the present invention is used as a liquid resist for an electrodeposition coating method to be described later, when a water-soluble photopolymerization initiator is used, the mixture is uniformly mixed with the polymerizable unsaturated resin. It is not preferable because electrodeposition becomes difficult.

In order to control the fluidity of the liquid photosensitive composition of the present invention, an extender such as mica, barium sulfate, calcium carbonate, silica, etc. is blended in an amount of 200 parts by weight or less based on 100 parts by weight of the resin component. Further, a coloring agent such as a coloring pigment, a dye or a leuco body thereof may be used in an amount of 30 parts by weight or less based on 100 parts by weight of the resin component for coloring the resist film. Further, for adjusting the dispersibility of the liquid photosensitive composition of the present invention, a surfactant or the like may be appropriately used.

The method of coating the photosensitive composition is not particularly limited, and any of the conventionally used methods, such as spray coating, roll coater coating, knife coater coating, date coating, screen coating, etc. A printing method or the like can be used, or in the case of an aqueous solution or an aqueous dispersion liquid photosensitive composition, an electrodeposition coating method can be applied. Particularly, in the case of electrodeposition coating, since the metal of the object to be coated is chelated at the interface with the deposited resin and the adhesive strength is increased, the resist film for etching punching of a metal plate having a thickness as thick as 100 μm or more is used. Particularly suitable for forming

The polymerizable unsaturated resin containing an anionic group which can be used in the photosensitive composition for electrodeposition coating has a carboxyl group content of 0.35 to 5.5 mol / kg, preferably 0.7. Water-soluble or water-dispersible carboxyl group having an unsaturated equivalent of 150 to 3000 and a number average molecular weight of 300 or more, preferably 1,000 to 30,000. Polymerizable unsaturated resins are preferred. Typical examples thereof include the following, but usable resins are not limited only to these examples.

(I) A polymerizable product obtained by adding a reaction product of a compound having a polymerizable unsaturated bond and a hydroxyl group in one molecule and a diisocyanate compound to a high acid value acrylic resin having a hydroxyl group in a skeleton. Unsaturated resin: Compounds having a polymerizable unsaturated bond and a hydroxyl group in one molecule include, for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, N -Methylolacrylamide, allyl alcohol, methallyl alcohol and the like. Examples of diisocyanate compounds include tolylene diisocyanate, xylylene diisocyanate, and hexamethylene diisocyanate. And lysine diisocyanate.

On the other hand, a high acid value acrylic resin is obtained by preparing a compound having a polymerizable unsaturated bond and a hydroxyl group in one molecule and an acid group-containing unsaturated monomer such as acrylic acid and methacrylic acid in the acrylic resin. It can be obtained by sometimes copolymerizing.

Urethane-forming reaction between a compound having a polymerizable unsaturated bond and a hydroxyl group in one molecule and a diisocyanate-based compound, and urethane-adding reaction between these reactants and a high acid value acrylic resin having a hydroxyl group in a skeleton The reaction can be performed by a usual method. (Ii) A polymerizable unsaturated compound obtained by adding an α, β-ethylenically unsaturated dibasic acid or its anhydride to an unsaturated bond in a fatty acid chain in an esterified product of an epoxy resin having an epoxy group and an unsaturated fatty acid. Resin whose main component is a mixture of a resin and an ethylenically unsaturated compound having at least one polymerizable unsaturated bond in one molecule: Examples of unsaturated fatty acids include oleic acid, linoleic acid, linolenic acid, Examples include rheostearic acid, ricanoic acid, ricinoleic acid, and arachidonic acid. An unsaturated carboxylic acid conjugated with a carbonyl group such as acrylic acid and / or methacrylic acid and / or crotonic acid may be used in combination. . Hereinafter, these may be collectively referred to as an unsaturated carboxylic acid.

Examples of the α, β-ethylenically unsaturated dibasic acid or its anhydride include maleic acid, maleic anhydride, fumaric acid, itaconic acid and the like. In this vehicle component, the acid value can be adjusted by the amount of the α, β-ethylenically unsaturated dibasic acid or anhydride added, and the unsaturated equivalent is determined by the type of unsaturated carboxylic acid and its amount used. Can be adjusted.

(Iii) A mixture mainly composed of a polymerizable unsaturated resin composed of an unsaturated fatty acid-modified high acid alkyd resin and an ethylenically unsaturated compound having at least one polymerizable unsaturated bond in one molecule. Resin: The polymerizable unsaturated resin is a mixture of a dibasic acid having two carboxyl groups in one molecule and a polybasic acid having three or more carboxyl groups in one molecule, and a mixture of two or more in one molecule. It is obtained by subjecting an unsaturated fatty acid to an esterification reaction with a hydroxyl group contained in the skeleton of an esterified product with a polyhydric alcohol having at least one hydroxyl group. In this case, the ratio of the number of moles of the acid component to the number of moles of the alcohol component is preferably in the range of 0.8 to 1.0.

In this reaction, the acid value can be adjusted by the type and amount of the polybasic acid, and the unsaturated equivalent can be adjusted by the amount of the unsaturated fatty acid added. Further, an unsaturated resin acid-modified alkyd resin having a hydroxyl group in excess of a carboxyl group may be half-esterified with a dibasic acid to give an acid value. In this system, examples of dibasic acids include phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, maleic anhydride, fumaric acid, succinic acid, sebacic acid and the like, and examples of polybasic acids include trimellitate Acid, pyromellitic acid, pyromellitic anhydride and the like. Examples of the polyhydric alcohol include ethylene glycol and propylene glycol.
Butylene glycol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, diglycerol, and the like. As the unsaturated fatty acid, the same unsaturated fatty acid as described above as used when the epoxy resin is reacted with the polymerizable unsaturated resin (ii) can be used.

(Iv) A resin mainly composed of a mixture of a polymerizable unsaturated resin comprising a maleated oil and an ethylenically unsaturated compound having at least one polymerizable unsaturated bond in one molecule: Include the reaction products of oils having conjugated or non-conjugated double bonds with maleic anhydride. Further, when styrene, vinyltoluene, cyclopentadiene, acrylic acid ester, methacrylic acid ester and the like are added to the reaction product, the curability of the coating film can be further improved. In these maleated oils, the acid value can be adjusted by the amount of maleic anhydride added, and the unsaturated equivalent can be adjusted by the unsaturated bonds contained in the oil. In this case, examples of the oil include linseed oil, tung oil, soybean oil, castor oil, coconut oil, sardine oil, cottonseed oil, hemp seed oil, and the like.

(V) A polymerizable unsaturated resin obtained by adding a compound having a polymerizable unsaturated bond and a glycidyl group in a molecule to a high acid value acrylic resin, or a polymerizable unsaturated bond and a polymerizable unsaturated bond in one molecule Resin based on a combination of an ethylenically unsaturated compound having at least one of the following: The polymerizable unsaturated resin is obtained by copolymerizing acrylic acid, methacrylic acid, or the like with another monomer. It can be produced by adding a compound having a polymerizable unsaturated bond and a glycidyl group in one molecule such as glycidyl acrylate and glycidyl methacrylate to an acid value acrylic resin.

(Vi) Photocurable resin containing a cinnamoyl group as a photosensitive group: The photocurable resin is, for example, a high acid value acrylic resin containing a hydroxyl group and a substituted or unsubstituted halide of cinnamic acid. Is reacted in the presence of a base, for example, in a pyridine solvent. The hydroxyl group-containing high acid value acrylic resin used at that time is, for example, α, β-ethylenically unsaturated acid such as acrylic acid and methacrylic acid and 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, methacrylic acid. A hydroxyalkyl ester of an ethylenically unsaturated acid such as hydroxypropyl acid is used as an essential component, and can be obtained by copolymerizing these with at least one unsaturated monomer.

In the production of such a hydroxyl group-containing high acid value acrylic resin, the α, β-ethylenically unsaturated acid generally has a photocurable resin having an acid value of 20 to 300,
Preferably, it can be used in an amount such that it falls within the range of 30 to 100. The hydroxyalkyl ester of the ethylenically unsaturated acid is generally used in an amount of 5 to 97 parts by weight per 100 parts by weight of the high acid value acrylic resin. , Preferably 20-7
It can be used in an amount such that it is within the range of 5 parts by weight.

On the other hand, the substituted or unsubstituted cinnamic halide is generally in the range of 6 to 180 parts by weight, preferably 30 to 140 parts by weight, per 100 parts by weight of the hydroxyl group-containing high acid value acrylic resin. Can be used in any amount.

Examples of the substituted or unsubstituted cinnamic halides which may be used include cinnamic halides which may have 1 to 3 substituents selected from a nitro group and a lower alkoxy group on the benzene ring. And more specifically cinnamic acid chloride, p-nitrocinnamic acid chloride, p
-Methoxycinnamic acid chloride, p-ethoxycinnamic acid chloride and the like.

The reaction between these substituted or unsubstituted cinnamic acid halides and the above-mentioned hydroxyl group-containing acrylic resin is carried out, for example, by adding 20 to 100 ml of pyridine to 100 parts by weight of an acrylic resin solution and adding 20 to 100 ml of dimethylformamide.
The purified product obtained by dropping cinnamic acid chloride dissolved in 100 ml at a temperature of 10 ° C. or less and then stirring at 30 to 70 ° C. for 3 to 8 hours gives a large excess of the reaction solution (150 to 150 ° C.).
(400 ml) of methanol to precipitate the polymer, reprecipitate with a mixture of tetrahydrofuran and water, and reprecipitate with a mixture of tetrahydrofuran and methanol.

In the polymerizable unsaturated resin described above,
In general, when the carboxyl group content is lower than 0.35 mol / kg resin, the water dispersibility decreases, and when the acid value is higher than 5.5 mol / kg resin, electrodeposition coating tends to be difficult. When the unsaturated equivalent is less than 150, the ability to form a coating film is reduced, and when it is more than 3000, the curability tends to be reduced. Further, when the number average molecular weight is less than about 300, the ability to form a coating film decreases, which is not preferred.

As the polymerizable unsaturated resin containing a cationic group that can be used in the liquid photosensitive composition for electrodeposition coating, the content of a cationic group (for example, a tertiary amino group or an onium base) is usually 0.2 to 0.2. 5 mol / kg resin, preferably 0.3
~ 2.0 mol / kg resin, the unsaturated equivalent is 150 ~ 30000 and the number average molecular weight is 300 or more,
Preferably, a water-soluble or water-dispersible polymerizable unsaturated resin in the range of 1,000 to 3,000 is used. Typical examples thereof include the following, but usable resins are not limited to these examples.

(A) a resin obtained by adding a reactant of a hydroxyl group-containing polymerizable unsaturated compound and a diisocyanate compound to an acrylic resin having a hydroxyl group and a tertiary amino group; (b) an epoxy resin A tertiary amino group-containing resin obtained by reacting the remaining epoxy group with a polymerizable unsaturated monocarboxylic acid or a hydroxy group-containing unsaturated compound after reacting with a secondary amine; (c) a glycidyl group-containing unsaturated compound And a resin obtained by copolymerizing a tertiary amino group-containing unsaturated compound with another polymerizable unsaturated monomer, and reacting with a polymerizable unsaturated monocarboxylic acid or a hydroxyl group-containing polymerizable unsaturated compound. (D) reacting an epoxy resin with a polymerizable unsaturated monocarboxylic acid or a hydroxyl group-containing unsaturated compound to obtain a residual epoxy resin; An onium base-containing resin obtained by onium salification of a tertiary amino group with a tertiary amino compound, thioether, phosphine or the like and a carboxylic acid. These resins can be used alone or in combination of two or more.

The cationically or anionic polymerizable unsaturated resin capable of being electrodeposited as described above is made water-soluble or water-soluble when an anionic group such as a carboxyl group is introduced into the resin. The reaction is carried out by neutralizing with an alkali (neutralizing agent) or, if a cationic group such as an amino group is introduced, with an acid (neutralizing agent). Will be Examples of the alkali neutralizing agent used at that time include monoethanolamine, diethanol-
Alkanolamines such as triamine, triethanolamine and the like; triethylamine, diethylamine, monoethylamine, diisopropylamine, trimethylamine,
Alkylamines such as diisobutylamine; alkylalkanolamines such as dimethylaminoethanol; alicyclic amines such as cyclohexylamine; alkali metal hydroxides such as caseiso-da and kaseikari; ammonia; Also, as an acid neutralizer,
For example, monocarboxylic acids such as formic acid, acetic acid, lactic acid, and butyric acid can be mentioned. These neutralizing agents can be used alone or in combination. The amount of the neutralizing agent to be used is generally 0.2 to 1.0 equivalent, preferably 0.3 to 0.3, per mole of the ionic group contained in the resin.
It is preferably within the range of 8 equivalents.

The preparation of the photosensitive composition for an electrodeposition coating composition can be carried out by a method known per se, for example, a resin which is water-dispersed or made water-soluble by the neutralization treatment, a photopolymerization initiator, If necessary, a solvent and other components can be mixed well and water can be added. The composition thus prepared is diluted with water in a usual manner at the time of use. For example, the pH is in the range of 4 to 9, the bath concentration (solids concentration) is 3 to 25% by weight, preferably 5 to 15%. It can be an electrodeposition paint (or coating bath) in the range of weight%.

The photosensitive electrodeposition paint thus prepared can be applied to the surface of a conductor to be coated, for example, as follows. As a conductor that can be used at that time, for example, a metal or alloy plate such as copper, nickel, chromium, aluminum, and iron, a metal plate coated with such a metal or alloy, or a foil of such a metal or alloy was applied Laminated plates, or laminated plates obtained by plating the above-mentioned metals or alloys on them are exemplified.

The temperature of the electrodeposition bath can generally be between 15 and 40 ° C., preferably between 15 and 30 ° C., and the pH and bath concentration are controlled within the stated ranges. Then, the conductor to be coated is immersed in the electrodeposition coating bath controlled as described above as an anode when the electrodeposition coating is an anion type and as a cathode when the electrodeposition coating is a cation type, and a voltage of 5 to 400 V is applied. Apply a DC voltage. The application time is suitably from 30 seconds to 5 minutes, and the obtained film thickness is generally from 2 to 30 μm, preferably from 5 to 25 μm in dry film thickness. After the electrodeposition coating, the object to be coated is pulled up from the electrodeposition bath, washed with water, and then the moisture and the like contained in the electrodeposition coating film are dried and removed with hot air or the like.

The preferred film thickness ranges for other coating methods are the same as described above. The wet film obtained by various coating methods removes the contained solvent, moisture and the like by hot air drying or the like. Generally, drying conditions are preferably 120 ° C. or lower and about 1 to 30 minutes.

In order to prevent curing of the applied resist film due to oxygen in the atmosphere, a resist or a solution containing a polymer having a high oxygen-blocking ability such as polyvinyl alcohol and polyvinylidene chloride as a main component can be obtained. 1 on the membrane
It is preferable to apply about 5 μm, whereby the surface curability of the resist film can be improved.

The resulting visible light-sensitive resist film is selectively cured by scanning exposure using a visible light laser in accordance with an image, and then the unexposed portion film is removed by a developing process. Can form an image. Visible light ray
As the light source, 458 nm, 488 nm or 51
Argon laser with oscillation line at 4.5 nm, 442n
A helium-cadmium laser having an oscillation line at m can be used. In the case of an anionic composition, the developing treatment is performed using an aqueous alkali solution such as sodium carbonate, caseisoda, caustic potash, aqueous ammonia, and in the case of a cationic composition, for example, acetic acid, formic acid, It can be performed using lactic acid or the like.

For the reasons described above, the exposure amount by a visible light laser is generally preferably 5 mJ / cm ² or less. However, the thickness of a thick metal plate was punched out by etching, and the image width was 150 μm or less. Highly detailed pattern
When etching is performed, the degree of cross-linking of the resist film is not sufficient for such processing even if the pattern at the time of development is good. It is difficult to withstand etching that is removed using an iron aqueous solution, a cupric chloride aqueous solution, or a mixed solution of ammonium chloride and ammonia water. As a result, defects such as no sharpness of the image, a reduction in the thickness of the copper, and a loss of part or all of the image occur.

The present invention prevents the above-mentioned defects from occurring by exposing the resist image by a visible light laser to a visible light and / or ultraviolet ray for a short time after the development processing, thereby easily preventing This makes it possible to obtain an etching resist film which has been sufficiently cross-linked and polymerized. The resist film formed by the method of the present invention is not affected by a ferric chloride aqueous solution, a cupric chloride aqueous solution or a mixed solution of ammonium chloride and ammonia water, and is subjected to a post-etching shear.
This has the surprising effect that an image without any defective elements can be obtained.

For the exposure to visible light and / or ultraviolet light after the development treatment according to the present invention, light having a wavelength in the range of usually 250 to 700 nm is suitable. Light sources containing light having these wavelengths include, for example, ultrahigh pressure, high pressure, medium pressure, and low pressure mercury lamps, chemical lamps, carbon arc lamps, xenon lamps, metal halide lamps, fluorescent lamps, tungsten lamps, laser lamps, and the like. Light, sunlight or the like can be used. Of these, an ultrahigh pressure, mercury lamp, high pressure mercury lamp, xenon lamp, and metal halide lamp are preferred. The above-mentioned irradiation with actinic rays is performed within several minutes, usually within one minute.

The metal portion (non-image portion) exposed by the developing process, for example, copper, is subjected to a normal etching process using an aqueous ferric chloride solution, an aqueous cupric chloride solution or a mixed solution of ammonium chloride and aqueous ammonia. Can be removed. Thereafter, the resist film on the image is formed with a strong alkali such as casei-oda in the case of a film of an anionic composition, or an organic acid or an inorganic acid in the case of a film of a cationic composition. By dissolving or swelling and removing with an organic solvent such as an aqueous solution or a chlorinated hydrocarbon, an etched product or a circuit pattern can be obtained.

[0052]

According to the above-described method of the present invention, the photocurable composition is coated on a metal plate, dried, exposed and cured according to an image using a visible light laser, and developed. After drying, exposure to visible light and / or ultraviolet light for a short period of time can form an image of a sufficiently cured etching resist film. The resist film formed by the method of the present invention exhibits excellent resist properties when etching a thick metal plate or when obtaining a fine circuit pattern by the etching method. After etching, even a fine image can be obtained with a sharp and defect-free image. According to the method of the present invention, the capacity of the visible light source can be reduced, and the time required for exposure can be greatly reduced. Image or punch pattern
The present invention can provide a method for producing a metal-etched product having metal.

[0053]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. In Examples, "parts" and "%" all indicate "parts by weight" and "% by weight" unless otherwise specified. Production Example 1 A mixture of 48 parts of methyl methacrylate, 12 parts of n-butyl acrylate, 40 parts of acrylic acid and 3 parts of azobisisobutyronitrile was kept in a nitrogen gas atmosphere at 110 ° C. in propylene glycol. The mixture was added dropwise to 90 parts of monomethyl ether in 3 hours. After dropping, the mixture was aged for 1 hour, and 1 part of azobisdimethylvaleronitrile and 10 parts of propylene glycol monomethyl ether 10
Was added dropwise over 1 hour and aged for 5 hours to obtain a high acid value acrylic resin (acid value 300) solution. Next, glycidyl methacrylate 50 was added to this solution.
Hydroquinone monomethyl ether (0.08 part) and tetraethylammonium bromide (0.6 part) were added and reacted at 110 ° C. for 5 hours while blowing air into the polymerizable unsaturated resin (acid value: 72, unsaturated equivalent: about 230, A solution having an average molecular weight of 15,000 and a Tg of 13 ° C.) was obtained.

After neutralizing the polymerizable unsaturated resin with 0.6 equivalents of triethylamine, 5 parts of a visible light polymerization initiator (titanocene compound) represented by the following chemical formula 1 and α-hydroxyisobutylphenone as an ultraviolet polymerization initiator After adding 6 parts, water was added so that the solid content became 10% to prepare an electrodeposition coating bath (PH 7.0).

[0055]

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Preparation Example 2 43 parts of methyl methacrylate, 22 parts of n-butyl acrylate, 20 parts of 2-hydroxyethyl methacrylate,
15 parts of acrylic acid and azobisisobutyronitrile 2
Part of the mixed system under nitrogen atmosphere.
It was dropped into 100 parts of dioxane (hydrophilic solvent) maintained at 5 ° C. over 2 hours, and aged at the same temperature for 1 hour to obtain a high acid value acrylic resin (acid value 113) solution. Next, 40 parts of an equimolar adduct of 2-hydroxyethyl methacrylate and tolylene diisocyanate and 0.07 part of hydroquinone monomethyl ether were added to 200 parts of the solution, and the mixture was heated to 80 ° C. while blowing air. The polymerizable unsaturated resin (acid value: about 80, unsaturated equivalent: about 1,000, number average molecular weight: about 2)
000, Tg of about 12 ° C.).

To this polymerizable unsaturated resin was added 3,3 ', 4,4'-tetra (tert-butyl perfluoro) as a radical generator.
6 parts of oxycarbonyl) benzophenone and the following chemical formula 2
3 parts of benzyl dimethyl ketal, a visible light polymerization initiator in combination with 1 part of the photosensitizer shown in the following , and ethyl acetate so that the solid content becomes 30% by weight. After dilution, a liquid resist was prepared.

[0058]

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Production Example 3 A mixture comprising 25 parts of methyl methacrylate, 15 parts of n-butyl acrylate, 15 parts of acrylic acid, 45 parts of 2-hydroxyethyl methacrylate and 2 parts of azobisisobutyronitrile was mixed with nitrogen. The mixture was dropped into 100 parts of DMF maintained at 80 ° C. in a gas atmosphere over 3 hours. After the dropwise addition, the mixture was aged for 1 hour, and a mixed solution composed of 1 part of azobisdimethylvaleronitrile and 5 parts of DMF (dimethylformamide) was added dropwise for 1 hour and further aged for 5 hours to obtain an acrylic resin (acid value 115) solution. Was.

To 200 parts of this polymerization solution, 120 parts of pyridine was added and 150 parts of DMF was dissolved in cinnamic acid chloride 57.
The mixture was added dropwise at 10 ° C. or lower, and then stirred at 50 ° C. for 4 hours. The reaction solution was poured into 500 parts of methanol to precipitate a polymer, reprecipitated with THF (tetrahydrofuran) -water, further precipitated with THF-methanol, purified and dried at room temperature under reduced pressure. The resulting photocurable resin having a cinnamoyl group as a photosensitive group had an acid value of 81, a Tg point of 51 ° C., and a number average molecular weight of about 20,000. The amount of cinnamoyl groups is 3.6
It was 9 mol / kg.

A solution prepared by dissolving 100 parts of the present resin in a mixed solvent of 50 parts of propylene glycol methyl ether and 50 parts of n-butanol was used.

To the polymerizable unsaturated resin, 1 part of a visible light polymerization initiator (titanocene compound) represented by the above chemical formula 1, 0.5 part of a photosensitizer represented by the following chemical formula 3, and benzyl methyl 3 parts of ketal was added and diluted with methyl ethyl ketone to a solid content of 30% to obtain a liquid resist.

[0063]

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Production Example 4 30 parts of glycidyl methacrylate, 5 parts of styrene, n-
24 parts of butyl methacrylate, 23 parts of methyl acrylate
, A mixed solution consisting of 18 parts of dimethylaminoethyl methacrylate and 5 parts of azobisisovaleronitrile was maintained at 80 ° C. in a nitrogen gas atmosphere.
It took 3 hours to add the solution dropwise. After the dropwise addition, the mixture was aged for 1 hour, and a mixed solution composed of 1 part of azobisdimethylvaleronitrile and 10 parts of cellosolve was added dropwise over 1 hour, and further added for 5 hours.
After aging for a time, an acrylic resin solution was obtained. Next, 15 parts of acrylic acid and 0.13 parts of hydroquinone were added to this solution, and the mixture was reacted at 110 ° C. for 5 hours while blowing air into the photocurable resin (amino group content: about 1.0 mol / kg,
Unsaturated equivalent weight 545, Tg 20 ° C, number average molecular weight about 15,
000) A solution was obtained.

After neutralizing the polymerizable unsaturated resin with 0.6 equivalents of formic acid, 4 parts of a visible light polymerization initiator (titanocene compound) represented by the above formula 1 and α-hydroxyisobutyl phenyl as an ultraviolet polymerization initiator After adding 6 parts of non,
Water was added so that the solid content became 10% to prepare an electrodeposition coating bath (PH 6.5).

[0066]

Example 1 Using the electrodeposition coating bath of Production Example 1 , copper thickness of 75 μm
The copper-clad laminate was used as an anode, and a DC current of 60 mA / dm ² was applied to the copper-clad laminate at a bath temperature of 25 ° C. for 3 minutes to perform electrodeposition coating. The maximum voltage at this time was 100V. This coating film was washed with water and air-dried to obtain a smooth photosensitive film having a thickness of 20 μm. Next, scanning exposure was performed at an intensity of ³ mJ / cm ² using an argon laser so as to draw an image having a line width of 60 μm, and then developed with 1% sodium carbonate, washed with water, dried, and dried at 80 watts.
/ Cm high pressure mercury lamp (distance between laminate and lamp 250m
After exposure for 2 seconds in step m), the copper in the exposed portion of the resist film by development was removed by etching treatment with a ferric chloride solution to obtain an image pattern. Next, the cured coating film on the exposed portion was peeled off and removed at 50 ° C. with a 3% aqueous solution of caseide soda, and the state of the image pattern was examined. The state of the pattern after peeling was such that there was no defect in the image and the thickness of the copper foil did not decrease. The accuracy of the line width of the obtained image is the specified line width (60 μm).
m) within ± 3%.

[0067]

EXAMPLE 2 The liquid resist of Production Example 2 was coated on a copper-clad laminate having a copper thickness of 75 μm with a bar coater so as to have a dry film thickness of 15 μm, dried at 80 ° C. for 10 minutes, and then dried with polyvinyl alcohol. A 5% aqueous solution of phenol was applied on the resist film to a dry film thickness of 2 μm and air-dried. Then, line width 50
After scanning and exposing with an intensity of 1 mJ / cm ² using an argon ion laser so as to draw an image of μm, development was carried out in the same manner as in Production Example 1. Exposure after development was performed using 8
Instead of a 0 w / cm high pressure mercury lamp, a 1 kW xenon lamp (250 mm distance between the laminate and the lamp) was used.
Go for 0 seconds. After the exposure, the copper foil exposed by the development was etched and removed using a cupric chloride solution to obtain an image pattern. Next, the cured coating film on the exposed portion was peeled off and removed at 50 ° C. with a 3% aqueous solution of caseide soda, and the state of the image pattern was examined. The state of the pattern after peeling was such that there was no defect in the image and the thickness of the copper foil did not decrease. The accuracy of the line width of the obtained image was within ± 3% of the specified line width (50 μm).

[0068]

Example 3 Using the liquid resist of Production Example 3, exposure after development was 80 w / cm instead of a 80 w / cm high pressure mercury lamp.
An image pattern was obtained on a copper-clad laminate in the same manner as in Example 2 except that a metal halide lamp (distance between the laminate and the lamp of 250 mm) was used for 2 seconds. Next, the cured coating film in the exposed area was washed with a 3% aqueous solution of caseidos for 50 hours.
After peeling and removal at ℃, the state of the image pattern was examined. The state of the pattern after peeling was not defective in the image, and the thickness of the copper foil did not decrease. The accuracy of the line width of the obtained image was within ± 3% of the specified line width (50 μm).

[0069]

Example 4 Using the electrodeposition coating bath of Production Example 4, a copper
μm copper-clad laminate for printed wiring (300 × 500 ×
(1.6 mm) as a cathode, a DC current of 50 mA / dm ² was applied to the copper-clad laminate at a bath temperature of 25 ° C. for 3 minutes to perform electrodeposition coating. The maximum voltage at this time was 80V. This coating film was washed with water and air-dried to obtain a smooth photosensitive film having a thickness of 20 μm. Next, after forming a polyvinyl alcohol film (2 μm) on the photosensitive film in the same manner as in Example 2, ² mJ / cm ² using an argon laser so as to draw an image having a line width of 60 μm.
And then developed with 1% acetic acid, washed with water and dried. Exposure after development was performed for 3 seconds with a 120 w / cm ultra-high pressure mercury lamp (lamps and lamp distance 250 mm).
The copper portion exposed by the development was subjected to an etching treatment with a mixed aqueous solution of ammonium chloride and aqueous ammonia. Next, the cured coating film on the exposed portion was peeled off and removed with a 1% aqueous acetic acid solution at 50 ° C., and the state of the image pattern was examined. The pattern after peeling did not show any defects in the image, and the thickness of the copper foil did not decrease. The accuracy of the line width of the obtained image is the specified line width (60 μm).
m) within ± 3%.

Comparative Example 1 An image pattern was obtained in exactly the same manner as in Example 1 except that an etching treatment was performed without performing exposure with a high-pressure mercury lamp after development. Etching and patterning after peeling of the cured coating on the exposed area
In this state, the image was partially lost and the copper foil was thinned. The line width of the obtained image was reduced by 30% or more with respect to the specified line width (60 μm).

Comparative Example 2 An image pattern was obtained in exactly the same manner as in Example 2 except that an etching treatment was performed without exposing with a xenon lamp after development. In the patterning state after the etching treatment and the peeling of the cured coating film in the exposed area, a part of the image was lost and the copper foil became thin. The line width of the obtained image is the specified line width (50 μm)
By more than 30%.

Comparative Example 3 An image pattern was obtained in exactly the same manner as in Example 3 except that an etching treatment was performed without performing exposure with a metal halide lamp after development. In the patterning state after the etching treatment and the peeling of the cured coating film in the exposed area, a part of the image was lost and the copper foil became thin. The line width of the obtained image is the specified line width (50 μm).
m) was reduced by 30% or more. Comparative Example 4 An image pattern was obtained in exactly the same manner as in Example 4 except that an etching treatment was performed without performing exposure with an ultrahigh pressure mercury lamp after development. Etching and patterning after peeling of the cured coating on the exposed area
In this state, the image was partially missing and the copper foil was thinned. The line width of the obtained image was reduced by 30% or more with respect to the specified line width (60 μm).

Comparative Example 5 In Example 1, exposure was performed at an intensity of 15 mJ / cm ² at a reduced scanning speed of the argon laser. Thereafter, the film was subjected to a development process, and an etching process was performed without performing exposure with a high-pressure mercury lamp after the development. In the pattern state after the cured coating film was peeled off in the exposed area, the image was not defective, but the line width of the obtained image was 20% or more larger than the specified line width (60 μm). A shot was seen in the part.

Example 5 A 300 μm thick copper plate was used as an anode using the electrodeposition coating bath of Production Example 1, and a DC current of 60 mA / dm ² was applied to the copper plate at a bath temperature of 25 ° C. for 4 minutes to perform electrodeposition coating. . The maximum voltage at this time was 120V. This coating film is washed with water and air-dried for 20 minutes.
A smooth photosensitive film having a thickness of μm was obtained. Next, a polyvinyl alcohol film was formed on the photosensitive film in a dry film thickness of 2
It was formed to have a thickness of μm. Next, the front and back surfaces are scanned and exposed at an intensity of 12 mJ / cm ² using an argon laser so as to draw an image having a line width of 60 μm, and then developed with a 1% aqueous sodium carbonate solution and washed with water. And dried. Next, the front and back surfaces were exposed for 3 seconds with an ultra-high pressure mercury lamp. After the copper exposed by the development was removed by etching using cupric chloride, the cured film was dissolved and removed at 50 ° C. using a 3% aqueous solution of sodium hydroxide. As a result, a good punch relief image was obtained. .

Comparative Example 6 In Example 5, when the front and back surfaces after the development processing were subjected to an etching treatment without being exposed by an ultra-high pressure mercury lamp, the resist film swelled or partially dissolved during the etching. Etching was performed, and the copper thickness of the image portion was reduced, and a part of the relief image was broken, so that a good punched image could not be obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kenji Seko 4-171-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Paints Kansai Paint Co., Ltd. (56) References JP-A-62-288826 (JP, A) 1-279251 (JP, A) JP-A-62-69613 (JP, A) JP-A-1-137634 (JP, A) JP-A-61-48922 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F ^7/ 00-7/42

Claims (1)

(57) [Claims] 1. A liquid photosensitive composition containing a photocurable resin containing a photosensitive group and an ionic group which can be crosslinked or polymerized by irradiation with visible light, a visible light polymerization initiator and an ultraviolet polymerization initiator. A method for forming an etching resist film, comprising exposing the coated plate with a visible light laser, developing the coated plate, and further exposing the coated plate to ultraviolet light.