JPH0766528A - Method of manufacturing printed-wiring board - Google Patents

Abstract

PURPOSE:To settle the issues on such points as the production of an electrodepositing solution, the stability in storage, etc., by containing surfactants in the electrodepositing solution. CONSTITUTION:An electrodepositing solution contains at least a photoconductive compound, a binding resin and surfactants. At this time, as for the photoconductive compound, either organic or inorganic photoconductive compounds can be used while various pigments, dyestuffs can be used together with one another for enhancing the sensitivity or for developing the sensitivity in specific wavelength regions. Furthermore, the binding resin bears the electrophotographic characteristics including the charging capacity, etc., and an anionic monomer having the solubility in an alkaline solution is copolymerized with a non-ionic monomer to adjust the resin composition while 0.001-10wt.% of non-ionic and anionic surfactants are used for the photoconductive compound. Accordingly, ion exchange water and surfactants are added to the electrodepositing solution containing the binding resin neutralized with a basic compound and the photoconductive compound dispersed in a solvent so that the printed-wiring board having excellent circuit pattern comprising photoconductive layer in thickness of 0.5-10mum may be realized.

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 a printed wiring board, and more specifically, it is obtained by forming a photoconductive layer on a metal conductive layer by an electrodeposition method and forming an etching resist by an electrophotographic method. The present invention relates to a method for producing a printed wiring board, which enables easy and quick production of an electrodeposition solution and has good storage stability of the electrodeposition solution.

[0002]

2. Description of the Related Art Generally, a printed wiring board is manufactured by laminating a photosensitive film on a conductive substrate having a copper foil as a metal conductive layer on an insulating substrate, exposing a photographic negative and exposing and developing the film. The unnecessary copper foil other than the circuit pattern was removed by etching, and the photosensitive film was removed to form a circuit pattern made of copper on the insulating substrate. In the method using this photosensitive film, since the thickness of the photosensitive film is generally as thick as about 50 μm, the formed circuit pattern is not sharp and it is difficult to uniformly laminate the copper foil surface.

Therefore, in order to improve the resolution and the like of the photosensitive film, JP-A-62-262855 and 64-4 are used.
Japanese Patent No. 672, etc. discloses a method for forming a photosensitive resist on a conductive substrate by an electrodeposition method. The electrodeposition method is a type of coating method that has been used for over 20 years. When the photosensitive layer is formed by the electrodeposition method, the photosensitive layer can be formed into a uniform thin film as compared with the laminating method. However, the photosensitive resist for electrodeposition is generally low in sensitivity and a few mJ / cm 2 for exposure. ²
Energy of ˜several hundred mJ / cm ² is required, and it is difficult to obtain a circuit pattern with high resolution.

On the other hand, as a method for producing a printed wiring board other than the above-mentioned photosensitive resist, West German Patent No. 1,117,39
No. 1, 2, 526, 720, 3, 210, 577
No. 52-2437, No. 57-48736,
A manufacturing method using an electrophotographic method is proposed in Japanese Patent Laid-Open No. 59-168462. A printed wiring board by electrophotography is provided with a photoconductive layer made of at least a photoconductive compound and a binder resin on a copper foil of a conductive substrate, and a toner image is formed on the photoconductive layer by a known electrophotographic method. After forming, remove the photoconductive layer in the non-image area other than the toner image area,
Further, the exposed copper foil is etched, and in some cases, the photoconductive layer on the circuit part copper foil is removed to produce the copper foil. JP 63-1
In 29689, the required exposure amount of the photoconductive layer is 1 μJ.
/ Cm ^{2 to} 50 μJ / cm ^{2, which} is low, enabling finer circuit patterns.

Conventionally, at least a photoconductive layer provided on a conductive substrate when a printed wiring board is manufactured is prepared by dissolving a binder resin and a photoconductive compound in a liquid or by sufficiently dispersing the liquid on the conductive substrate. It is applied by a known method, is applied on a temporary substrate once and is transferred onto a copper foil of a conductive substrate by heat and pressure, or by an electrodeposition method. However, in general, the photoconductive compound used in the electrophotographic photoconductive layer requires time to disperse the photoconductive compound if at least a part of the photoconductive compound is insoluble in the binder resin-containing solution. There has been a problem with storage such that the photoconductive compound precipitates and the electrodeposition component changes over time.

[0006]

The present invention relates to a method for producing a printed wiring board, more specifically, a photoconductive layer is formed on a metal conductive layer by an electrodeposition method, and an etching resist is formed by an electrophotographic method. It is an object of the present invention to provide a method for producing a printed wiring board, which is capable of easily and quickly producing an electrodeposition solution and has good storage stability of the electrodeposition solution.

[0007]

Means for Solving the Problems As a result of intensive investigations by the present inventors, an electrodeposition liquid containing at least a photoconductive compound and a binder resin on a conductive substrate provided with a metal conductive layer on an insulating substrate. To form a photoconductive layer by an electrodeposition method using, to form a toner image on the photoconductive layer by electrophotography, and then elute and remove the photoconductive layer other than the toner adhesion portion,
In the method for producing a printed wiring board in which the photoconductive layer-removed portion metal conductive layer is removed by etching, the electrodeposition solution contains a surfactant in order to solve the problems such as the preparation property and storage stability of the electrodeposition solution. I came to find what I should do. By using the method for producing a printed wiring board of the present invention, an electrodeposition solution can be produced easily and quickly, and a stable electrodeposition solution can be used to obtain a printed wiring board having a good circuit pattern. it can.

The present invention will be described in detail below. The electrodeposition liquid according to the present invention is at least a photoconductive compound, a binder resin,
And a surfactant. Organic and inorganic photoconductive compounds can be used as the photoconductive compound.
Examples of the inorganic photoconductive compound include selenium and selenium alloys, amorphous silicon, cadmium sulfide, zinc oxide, zinc sulfide and titanium oxide. Examples of organic photoconductive compounds include a) US Pat. No. 31.
12197, etc., a triazole derivative,
b) Oxadiazole derivatives described in U.S. Pat. No. 3,189,447, c) Imidazole derivatives described in Japanese Patent Publication No. 37-16096, etc. d) U.S. Pat. No. 35
42544, 3615402 and 3820989.
Specification, Japanese Examined Patent Publication No. 45-555, 51-10983
JP-A-51-93224 and JP-A-55-108667.
Nos. 55-156953, 56-36656 and the like, e) U.S. Pat. Nos. 3,180,729, 4,278,746, JP-A-55-88064, and JP-A-55-88065. , The same 4
9-105537, 55-51086, 56-
80051, 56-88141, 57-455.
No. 45, No. 54-112637, No. 55-74546.
Derivatives of pyrazoline and pyrazolone described in JP-B No. 3615404, f) U.S. Pat. No. 3,615,404
1-10105, 46-3712, 47-28.
336, JP-A-54-83435, and JP-A-54-110.
836, 54-119925, etc., phenylenediamine derivatives, g) US Pat. No. 3,567,450.
No. 3,180,703, 3,240,597, 36.
No. 58520, No. 4232103, No. 4175961.
No. 4012376, West German Patent (DAS)
11010518, Japanese Examined Patent Publication No. 49-35702, 39
-27577, JP-A-55-144250, 56
-119132, 56-22437, etc. arylamine derivatives, h) US Patent 352650.
1, amino substituted chalcone derivatives, i) N, N-bicarbazyl derivatives described in US Pat. No. 3,542,546, j) oxazole derivatives described in US Pat. No. 3,257,203, k) special Kaisho 56-46
Styrylanthracene derivatives described in Japanese Patent No. 234, etc.,
l) Fluorenone derivatives described in JP-A-54-110837, m) US Pat. No. 3,717,462, JP-A-54-59143 (US Pat. No. 4,1509)
No. 87), No. 55-52063, No. 55-52
No. 064, No. 55-46760, No. 55-85495.
No. 57-11350, No. 57-148749,
Hydrazone derivatives described in JP-A-57-104144, n) US Pat.
No. 9, No. 4265990, No. 4273846, No. 4
299897 and 4306008, etc., benzidine derivatives, o) JP-A-58-190953,
59-95540, 59-97148, 59
-195658, 62-36674 and the like stilbene derivatives, p) polyvinylcarbazole and its derivatives described in JP-B-34-10966.
q) Polyvinylpyrene, polyvinylanthracene, poly-2-vinyl-4- (4'-dimethylaminophenyl)-described in JP-B Nos. 43-18674 and 43-19192.
Vinyl polymers such as 5-phenyloxazole and poly-3-vinyl-N-ethylcarbazole, r) JP-B-43-191
Polymers such as polyacenaphthylene, polyindene, and acenaphthylene / styrene copolymers described in JP-A-93,
s) Pyrene described in Japanese Patent Publication No. 56-13940 /
Condensation resins such as formaldehyde resin, ethylcarbazole / formaldehyde resin, t) JP-A-56-9088
3, various triphenylmethane polymers described in JP-A-56-161550 and the like, u) US Pat. No. 3,397,086.
No. 4,666,802, JP-A-51-90827,
No metal or metal (oxide) described in JP-A No. 52-655643, JP-A No. 64-2061 and JP-A No. 64-4389.
Examples include phthalocyanine and naphthalocyanine, and their derivatives. The organic photoconductive compound according to the present invention comprises a)
To u), other organic photoconductive compounds can be used. Two or more kinds of these organic photoconductive compounds can be used in combination, if desired.

Further, in the present invention, various pigments, dyes and the like can be used in combination for the purpose of improving the sensitivity of the photoconductive layer and imparting sensitivity to a desired wavelength range. Examples of these are: 1) U.S. Pat. Nos. 4,436,800 and 4,439,506; JP-A-47-37543;
58-123541, 58-192042, 58-219263, 59-78356, 60.
-179746, 61-148453, 61-
238063, Japanese Patent Publication No. 60-5941, No. 60-4
Monoazo, bisazo, and trisazo pigments described in Japanese Patent No. 5664, 2) Perylene pigments described in US Pat. No. 3,371,884, and 3) British Patent No. 2237680.
Indigo, thioindigo derivative, etc.
4) Quinacridone pigments described in British Patent No. 2237679, etc., 5) British Patent No. 2237678, Japanese Patent Laid-Open Nos. 59-184348 and 62-28738.
Polycyclic quinone-based pigments described in JP-A No. 6-63, 6) JP-A-47-
Bisbenzimidazole pigments described in, for example, 30331, 7) U.S. Pat. Nos. 4,396,610 and 46,440.
No. 82 and the like, 8) Squalium salt-based pigments, 8) Azurenium salt-based pigments, such as those described in JP-A-59-53850 and JP-A-61-212542. In addition, as the sensitizing dyes, "electrophotographic" 12 9 (1973), "Synthetic Organic Chemistry" 24 No. Known compounds described in 11 1010 (1966) and the like can be used. For example, 9) U.S. Pat. Nos. 3,141,770 and 42,834.
No. 75, Japanese Patent Publication No. 48-25658, Japanese Patent Laid-Open No. 61
Pyrylium dyes described in JP-A-71965, 1
0) Applied Optics Supplement 3 50 ( 196
9), triarylmethane dyes described in JP-A No. 50-39548, 11) U.S. Pat. No. 3,597,196.
Cyanine dyes described in JP-A No. 9-96, 12) JP-A-59
No. 164588, No. 60-163047, No. 60-
Examples thereof include styryl dyes described in Japanese Patent No. 252517. These sensitizing dyes may be used alone or in combination of two or more.

In order to improve the sensitivity of the photoconductive layer according to the present invention, compounds such as trinitrofluorenone, chloranil, tetracyanoethylene and the like, JP-A-58-65439,
The compounds described in JP-A-58-102239, JP-A-58-129439 and JP-A-60-71965 can be used in combination.

The binder resin according to the present invention must satisfy the electrophotographic characteristics including chargeability and the like and be soluble in an alkaline solution. In producing a printed wiring board, it is necessary to etch the metal conductive layer in the non-image area with an acid solution, so that a resin having an anionic functional group is particularly used in order to develop etching resistance. When the composition ratio of the anionic monomer in the binder resin in the formed photoconductive layer is high, it is easily redissolved in water, the resin film becomes brittle, and the ionic conductivity becomes high, resulting in dark chargeability and the like. Since the electrophotographic properties deteriorate, the binder resin according to the present invention is prepared by copolymerizing an anionic monomer with a nonionic monomer to appropriately adjust the resin composition.

Among the resins having an anionic functional group, the monomer-containing copolymer having a carboxylic acid group and the phenol resin have high charge retention and can be advantageously used. Examples of the monomer-containing copolymer having a carboxylic acid group include a copolymer of styrene and a maleic acid monoester, a copolymer of acrylic acid or methacrylic acid and an alkyl ester, aryl ester or aralkyl ester of two or more thereof. Polymers are preferred. Further, a copolymer of vinyl acetate and crotonic acid is also preferable. Particularly preferred phenolic resins include novolak resins obtained by condensing phenol, o-cresol, m-cresol, or p-cresol with formaldehyde or acetaldehyde under acidic conditions.

Specific examples of the binder resin according to the present invention include styrene / maleic acid monoalkyl ester copolymer, methacrylic acid / methacrylic acid ester copolymer, and styrene /
Methacrylic acid / methacrylic acid ester copolymer, acrylic acid / methacrylic acid ester copolymer, methacrylic acid /
Methacrylic acid ester / acrylic acid ester copolymer,
Styrene / methacrylic acid / acrylic acid ester copolymer, styrene / acrylic acid / methacrylic acid ester copolymer, vinyl acetate / crotonic acid copolymer, vinyl acetate /
Styrene such as crotonic acid / methacrylic acid ester copolymer, vinyl benzoate / acrylic acid / methacrylic acid ester copolymer, etc., and carboxylic acid-containing monomers such as vinyl benzoate, vinyl benzoate, etc. And a copolymer containing a methacrylic acid amide, a phenolic hydroxyl group, a sulfonic acid group, a sulfonamide group, a sulfonimide group, a phosphonic acid group-containing monomer, a phenol resin, a xylene resin, and the like. To be These binder resins may be used alone or in combination of two or more.

The binder resin according to the present invention preferably has a weight average molecular weight of 5,000 to 200,000, more preferably 15,000 to 100,000. If the molecular weight is less than 5,000, the mechanical strength of the photoconductive layer provided on the conductive metal substrate is poor, and if it exceeds 200,000, the non-image area photoconductive layer after toner development is eluted into the eluent. Remarkably low in sex.

The mixing ratio of the photoconductive compound according to the present invention to the binder resin varies depending on the electrophotographic characteristics of the photoconductive layer, but is preferably in the range of about 1 to 100% by weight of the resin amount, more preferably 5%. ~ 40% by weight is good.

As the surfactant according to the present invention, a nonionic surfactant and an anionic surfactant are particularly preferable in view of miscibility with the binder resin. In particular, the nonionic surfactant lowers the surface tension, improves the wettability of the photoconductive compound, and further suppresses the bubbles that are the cause of the unevenness of the photoconductive layer during electrodeposition due to its foam suppression effect. Therefore, it is more preferably used. For example, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyryl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, pentaerythritol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, glycerin fatty acid ester, Nonionic surfactants such as acetylene diol and polyoxyethylene-added acetylene diol, fatty acid salts, abietic acid salts, alkane sulfonates, hydroxyalkane sulfonates, dialkylsulfosuccinates, alkylbenzene sulfonates, alkylnaphthalene sulfones Acid salts, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfo Phenyl ether salts, N-alkyl sulfosuccinic acid monoamide salts, petroleum sulfonates, fatty acid alkyl ester sulfate ester salts, alkyl sulfate ester salts, polyoxyethylene alkyl ether sulfate ester salts, polyoxyethylene alkylphenyl ether sulfate ester salts, Fatty acid monoglyceride sulfate ester salt, alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphate ester salt, polyoxyethylene alkylphenyl ether phosphate ester salt, partially saponified styrene / maleic anhydride copolymer, olefin / maleic anhydride Examples include anionic surfactants such as partially saponified acid copolymers and naphthalene sulfonate formalin condensates.

The above surfactants may be used alone or in combination of two or more. When two or more kinds are used, it is preferable that one has a foam suppressing effect. The surfactant is used in the range of 0.001 to 10% by weight, more preferably 0.01 to 5% by weight, based on the photoconductive compound. If the amount of the surfactant is less than 0.001% by weight, the dispersion of the photoconductive compound, the binder resin and the solvent is poor, the dispersion time becomes long and the storage stability deteriorates. On the other hand, if it exceeds 10% by weight, the electrophotographic characteristics such as the charging property of the formed photoconductive layer are deteriorated.

In order to carry out electrodeposition of the photoconductive layer, it is necessary to uniformly disperse the binder resin and the photoconductive compound in the electrodeposition liquid, or preferably to dissolve them. Therefore, it is preferable to neutralize a part or all of the anionic groups in the binder resin with a basic compound in advance. Examples of the basic compound include alkanolamines such as monoethanolamine, diethanolamine and triethanolamine as organic basic compounds, alkylamines such as triethylamine, diethylamine, monoethylamine, diisopropylamine, trimethylamine and diisobutylamine, and dimethylaminoethanol. Alkyl alkanolamines such as etc., alicyclic amines such as cyclohexylamine, morpholine and the like, and inorganic basic compounds such as alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, sodium carbonate, potassium carbonate and the like. Alkali metal carbonate, ammonia, etc. can be used.

These basic compounds can be used alone or as a mixture. The neutralization amount of the binder resin with the basic compound is preferably in the range of 0.3 to 1.3 equivalents with respect to one ion equivalent of the ionic group such as carboxylic acid in the binder resin. If the neutralization amount is less than 0.3 equivalent, the dispersibility of the photoconductive composition in water is reduced, making it difficult to form a uniform electrodeposition film. Stability decreases.

The electrodeposition liquid according to the present invention can be obtained by dispersing a binder resin neutralized with a basic compound and a photoconductive compound in a suitable solvent and then adding ion-exchanged water. The surfactant according to the present invention may be added at appropriate times such as when the binder resin and the photoconductive compound are dispersed, when ion-exchanged water is added, and after addition. The surfactant may be added as it is or after being dissolved in a suitable solvent.

As the solvent for the electrodeposition liquid used in the present invention, a general organic solvent can be used, but a water-miscible solvent is preferable because water is added to the electrodeposition liquid, and its specific example is methyl cellosolve, Ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, 2-hydroxyethyl acetate, monoglyme, diglyme,
Tetrahydrofuran, dioxolane, dioxane, dimethylformamide, dimethylacetamide, methyl ethyl ketone, furfural and the like can be used.

The solid content concentration in the electrodeposition liquid used in the present invention is preferably in the range of 1% by weight to 30% by weight, more preferably 5% by weight to 20% by weight. By keeping the solid content concentration constant, the film thickness can be easily controlled by the amount of electricity supplied.

A typical example of the conductive substrate having a metal conductive layer provided on the electrically insulating substrate used in the present invention is a laminate of a phenol resin-impregnated laminated plate, an epoxy resin-impregnated laminated plate and the like with a copper foil laminated thereon. It is a thing. Examples of these conductive substrates are described in "Printed Circuit Technology Handbook" (edited by Japan Printed Circuit Industry Association, published in 1987, published by Nikkan Kogyo Shimbun), and any desired conductive substrate can be used. .

Various thicknesses of copper foil can be used, and generally 5 μm to 35 μm is used, but thicker and thinner ones can also be used. As the wiring density becomes higher and the conductor line width becomes narrower, it is better to use thin copper foil.

The photoconductive layer is formed on the conductive substrate by the electrodeposition method. The electrodeposition method is performed by immersing a conductive substrate for a printed wiring board and a metal plate serving as a counter electrode in an electrodeposition liquid, and applying an appropriate potential between them. The ionic binder resin that has migrated to the surface of the conductive substrate electrochemically reacts with it, loses its ionicity, becomes insoluble, and is deposited on the surface of the conductive substrate.

The electrodeposition method can use the same device as the conventional electrodeposition coating. The formed photoconductive layer is generally porous as it is, and becomes a uniform layer by heat drying. In addition, a stable dark charging property can be obtained by this drying process.

If the photoconductive layer provided on the conductive substrate is thin, the necessary electric charges cannot be charged by the electrophotographic method. On the contrary, if the photoconductive layer is thick, the alkali eluate is deteriorated when the photoconductive layer in the non-image area is removed. In addition to the acceleration, line thinning of the image occurs, and an image with good reproducibility cannot be obtained. Photoconductive layer is 0.5
The thickness is preferably 10 μm to 10 μm, and it is preferable to set the photoconductive layer manufacturing conditions so as to achieve this thickness.

In the method for producing a printed wiring board of the present invention, a toner image is formed on the photoconductive layer provided on the conductive substrate metal conductive layer by electrophotography. That is, the photoconductive layer used in the present invention is charged substantially uniformly in a dark place, the charge in the exposed portion is eliminated by imagewise exposure to form an electrostatic latent image, and then toner development is performed. Examples of the exposure method include reflection image exposure using a xenon lamp, tungsten lamp, fluorescent lamp, or the like as a light source, contact exposure through a transparent positive film, and scanning exposure with laser light, a light emitting diode, or the like. For scanning exposure, He-Ne laser, H
e-Cd laser, argon ion laser, krypton ion laser, ruby laser, YAG laser,
Nitrogen laser, dye laser, excimer laser,
Scanning exposure with a semiconductor laser such as GaAs / GaAlAs or InGaAsP, laser light source such as alexandrite laser, copper vapor laser, or scanning exposure using a light emitting diode or liquid crystal shutter (line using a light emitting diode array, liquid crystal shutter array, etc. (Including a printer-type light source).

The light source used for exposing the charged photoconductive layer varies depending on the type of the photoconductive compound used. For example, a semiconductor laser can be used when χ-type metal-free phthalocyanine is used, and an argon laser can be used when ε-type copper phthalocyanine and an anzanthrone compound having a spectral absorption around 500 nm are used.

Next, the formed electrostatic latent image is developed with toner. As a toner developing method, a dry developing method (cascade developing, magnetic brush developing, powder cloud developing)
Alternatively, a developing method using liquid toner in which toner particles are dispersed in a suitable insulating liquid can be used. Among them, the liquid developing method can stably make the toner particles smaller than the dry developing method, and thus a finer toner image can be formed. Therefore, the liquid developing method is preferably used in the invention. .

The toner used in the present invention may be a wet type toner used in electrophotographic printing plates.
It must have resist properties for the subsequent step of removing the photoconductive layer in the non-image area and etching the metal conductive layer exposed thereby. For this purpose, as the resin component, for example, acrylic resin composed of methacrylic acid, methacrylic acid ester, etc., vinyl acetate resin, a copolymer of vinyl acetate and ethylene or vinyl chloride, vinyl chloride resin, vinylidene chloride resin, polyvinyl butyral Such vinyl acetal resins, polystyrene, copolymers of styrene and butadiene, methacrylic acid ester, etc., polyethylene, polypropylene and chlorides thereof,
Polyester resins such as polyethylene terephthalate and polyethylene isophthalate, polyamide resins such as polycapramide and polyhexamethylene adipamide, phenol resins, xylene resins, alkyd resins, vinyl-modified alkyd resins, cellulose ester derivatives such as gelatin and carboxymethyl cellulose, and other waxes. , Wax and the like are preferably contained. Further, the toner may contain a dye or a charge control agent as long as it does not adversely affect development or fixing. Furthermore, it is necessary to use positive or negative charging depending on the photoconductive compound used and the charging polarity at the time of corona charging.

As a developing method, a positive developing method of developing a non-exposed portion by using a toner having a charge having a polarity opposite to that of the electrostatic latent image, a suitable bias using a toner having a same polarity as the electrostatic latent image are used. There is a reversal development method in which an exposed portion is developed under application of a voltage. The formed toner image is heated and fixed, for example.
It can be fixed by a known method such as pressure fixing or solvent fixing.
The toner image thus formed is used as a resist to remove the non-image area photoconductive layer with an eluent to form an image area consisting of the photoconductive layer and toner on the metal conductive layer.

As a method for eluting and removing the toner-developed portion of the photoconductive layer on which the toner image is not formed, basically, an elution treatment for a non-image area elution type printing plate using an alkali eluent is carried out. Can be used. The alkaline eluent used in the present invention contains a basic compound. Examples of the basic compound include inorganic basic compounds such as alkali metal silicates, alkali metal hydroxides, phosphoric acid and alkali metal carbonates and ammonium salts, ethanolamines, ethylenediamine, propanediamines, triethylenetetramine, morpholine. An organic basic compound or the like can be used. The above basic compounds can be used alone or as a mixture. Water can be advantageously used as a solvent for the alkaline eluate.

The etching removal is a step of removing the exposed copper foil by removing the photoconductive layer by the above-mentioned elution removal. The above-mentioned "Printed Circuit Technical Handbook" (edited by Japan Printed Circuit Industry Association, published in 1987, published daily) The method described in Kogyo Shimbun) can be used. Also,
The etching solution is also one that can dissolve and remove the copper foil, and if the photoconductive layer has acid resistance, it is sufficient to use ferric chloride solution, cupric chloride solution, etc. with general printed board etching solutions. Can be used.

Basically, a copper foil pattern necessary for a circuit can be obtained through the etching process, but the photoconductive layer and toner are present in the unetched portion. These may exist as they are, but they may become unnecessary when connecting circuit components, chips, and the like. At this time, these can be removed by treating with a solution having a stronger alkalinity as in the case of manufacturing a printed wiring board using a general photosensitive polymer. If necessary, an organic solvent capable of dissolving the photoconductive layer binder resin such as methyl ethyl ketone, dioxane, methanol, ethanol, propanol, butanol can be used.

[0036]

EXAMPLES The present invention will be described more specifically by way of examples. The present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Example 1 Synthesis of Binder Resin 90 parts by weight of dioxane was added to methacrylic acid 20 in a nitrogen atmosphere.
By weight, a mixed liquid of 35 parts by weight of methacrylic acid benzyl ester, 45 parts by weight of acrylic acid n-butyl ester, and 2.0 parts by weight of azobisisobutyronitrile was added dropwise over 4.5 hours. To this, 0.25 parts by weight of azobisisobutyronitrile and 10 parts by weight of dioxane were added dropwise,
It was further heated for 1.5 hours to obtain a binder resin solution. The weight average molecular weight of the obtained binder resin was 30,000.

Preparation of electrodeposition liquid and 50 parts by weight of the binder resin solution neutralized with electrodeposition triethylamine was added to χ type metal-free phthalocyanine (Dainippon Ink and Chemicals, Inc.).
Product name: Fastogen blue # 8120) 10 parts by weight, acetylene alcohol surfactant (Nisshin Chemical Co., Ltd., product name Surfynol 104) is 0.001 parts by weight per 1 part by weight of the photoconductive compound. After the addition of 1 part, the mixture was dispersed with a paint shaker for 10 minutes, and ion-exchanged water was added so that the solid content concentration was 10% to obtain an electrodeposition solution A. The electrodeposition liquid A is uniform,
It was stable for 10 weeks and no sedimentation of photoconductive compounds was observed. Conductive substrate for printed wiring board using this electrodeposition liquid A (300 × 3000 × 1.6 mm, copper foil thickness: 18 μm)
Was used as an anode, and a direct current of 50 mA / dm ² was applied for 1 minute at a bath temperature of 25 ° C. to perform electrodeposition. The obtained photoconductive layer is 9
It was dried at 0 ° C. for 20 minutes to obtain a conductive substrate having a uniform photoconductive layer with a thickness of about 5 μm. When a photoconductive layer was prepared using the electrodeposition liquid A even after 10 weeks, no coating unevenness was confirmed.

Evaluation of Photoconductive Layer The formed photoconductive layer had good adhesion to the copper surface and was able to follow irregularities on the copper surface due to scratches.
The electrophotographic characteristics of this copper clad laminate were measured with an electrostatic field measuring instrument SP-4.
When evaluated with 28 (manufactured by Kawaguchi Electric Co., Ltd.), V
₀ (initial potential) +300 V, DD ₁₀ (dark decay potential retention after 10 seconds) were 95%. The electrophotographic characteristics of the photoconductive layer prepared by using the electrodeposition liquid after standing for 10 weeks were V ₀ +297 V and DD ₁₀ 95%, and no deterioration was confirmed.

Formation of toner image A conductive substrate on which a photoconductive layer is formed is +300 V in a dark place.
After charging to, an electrostatic latent image having a line width of 40 μm was formed on the photoconductive layers on both sides by a laser plotter having a wavelength of 780 nm. This latent image was formed using a toner "ODP-TW" for Mitsubishi OPC printing system (manufactured by Mitsubishi Paper Mills Ltd.)
The copper portion of the conductive substrate was grounded, and a bias voltage of +100 V was applied to the developing electrode for reverse development. The toner image was fixed by drying with hot air at 70 ° C. for 1 minute.

Elution removal of non-image area photoconductive layer Elution solution "ODP-" for Mitsubishi OPC printing system
DF _II "(manufactured by Mitsubishi Paper Mills Ltd.) is used to elute and remove the photoconductive layer in the area where the toner is not adhered to form a circuit pattern with the toner image and the undissolved photoconductive layer underneath as the image portion. Formed.

Etching The wiring image consisting of the toner and the undissolved photoconductive layer formed on the conductive substrate by elution of the non-image area photoconductive layer is used as an etching resist, and the substrate is heated to 40 ° C. with 42 ° Baume. The ferric chloride etching solution was sprayed at a spraying pressure of 2.5 kg / cm ² for 1 minute to remove the etching resist uncoated metal conductive layer. After that, when the etching resist composed of the toner and the photoconductive layer was removed with a 3.0% sodium hydroxide solution, a copper circuit having a line width of about 40 μm was formed in the etching resist portion.

Comparative Example 1 Preparation of Electrodeposition Solution An electrodeposition solution B was prepared in the same manner as the electrodeposition solution A prepared in Example 1 except that no surfactant was added. However, the dispersion time was 25 minutes. The electrodeposition liquid B was uniform immediately after preparation, but after one week, precipitation of the photoconductive compound was confirmed.

Evaluation of photoconductive layer and production of printed wiring board
When manufacturing the conductive prepare a photoconductive layer in the same manner as conductive substrate as in Example 1 by using the Chakueki B, it was evaluated photoconductive layer,
The photoconductive layer was uniform and had V ₀ +300 V and DD ₁₀ 94%. When a printed wiring board was produced using this photoconductive layer, a clear circuit pattern was obtained. However, when the electrodeposition solution B after storage for 1 week was used for electrodeposition, the evaluation of the photoconductive layer and the production of a printed wiring board were performed in the same manner, the photoconductive layer obtained on the conductive substrate was partially It was non-uniform, and its electrophotographic characteristics were V ₀ +290 V and DD ₁₀ 93%, and the charge retention was lowered. In addition, it was confirmed that the printed circuit board produced was partially broken.

Example 2 In the electrodeposition solution A prepared in Example 1, the same conditions as in Example 1 were used except that the surfactant, the addition amount thereof and the dispersion time were as shown in Table 1. H was produced.

[0046]

[Table 1] Note 1] What is Surfactant I? Acetylene alcohol surfactants (Nisshin Chemical Co., Ltd., trade name Surfynol 10
4) and surfactant II are decaglycerin fatty acid ester (manufactured by Nippon Surfactant Industry Co., Ltd., trade name NIKK
OL Decaglyn 1-L) and surfactant III are N-acyl amino acid salts (manufactured by Nippon Surfactant Industry Co., Ltd., trade name NIKKOL sarcosinate LK-).
30). Note 2] The amount of surfactant added is expressed in parts by weight relative to 1 part by weight of the photoconductive compound.

When the content of the surfactant is 0.01 to 5% by weight relative to 1 part by weight of the photoconductive compound (electrodeposition liquids D to G), the dispersibility of the electrodeposition liquid is good, and the long term of about 3 months is maintained. It showed storage stability. Moreover, when a photoconductive layer was prepared on a conductive substrate during the preparation of the electrodeposition solution and after storage for 3 months using these electrodeposition solutions, a uniform layer was obtained, and the electrophotographic characteristics of the electrodeposition solution were It was almost the same as when A was used. No change in the components of the electrodeposition layer with time was observed. When a printed wiring board was produced using a conductive substrate provided with a photoconductive layer, a clear circuit pattern was obtained.

In the electrodeposition liquid C in which the content of the surfactant was 0.001 part by weight to 1 part by weight of the photoconductive compound, the dispersion time of the photoconductive compound in the binder resin was prolonged, but The photographic characteristics and storage stability were good, with no difference from the electrodeposition liquid A, and good fine line images could be obtained on the printed wiring board prepared using the electrodeposition liquid C.

With the electrodeposition liquid H in which the content of the surfactant is 10 parts by weight relative to 1 part by weight of the photoconductive compound, there is no problem in dispersibility, and an electrophotograph of the photoconductive layer formed on the conductive substrate. The characteristics were the same as those when the electrodeposition liquid A was used, and the printed wiring board using this had a good wiring pattern. However, with this electrodeposition solution H, the storage stability was slightly lowered, and after 8 weeks, the precipitation of the photoconductive compound was confirmed, the photoconductive layer formed using this solution was uneven, and its electrophotographic characteristics were It was V ₀ +290 V and DD ₁₀ 91%. A disconnection was confirmed in the circuit pattern of the printed wiring board manufactured using this photoconductive layer.

[0050]

As described above, according to the method for producing a printed wiring board of the present invention, an electrodeposition solution can be produced easily and quickly, and by using a stable electrodeposition solution for long-term storage. A printed wiring board having a good circuit pattern can be obtained.

Claims (1)

[Claims] 1. A photoconductive layer is formed by an electrodeposition method using an electrodeposition liquid containing at least a photoconductive compound and a binder resin on a conductive substrate provided with a metal conductive layer on an insulating substrate,
Further, a toner image is formed on the photoconductive layer by an electrophotographic method, and then the photoconductive layer other than the toner-adhered portion is eluted and removed, and the photoconductive layer-removed portion metal conductive layer is removed by etching. A method for producing a printed wiring board, characterized in that the electrodeposition liquid contains a surfactant.