JPS6267895A - Manufacturing circuit board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing single-sided and double-sided circuit boards having no through holes or non-conducting through holes. More specifically, the present invention relates to a method for manufacturing a circuit board having no through holes or having non-conducting through holes, which is capable of producing high-density wiring patterns, and is highly reliable and economical.

(Prior Art and its Problems) Conventionally, various methods have been used to manufacture single-sided and double-sided circuit boards that do not have through holes or have through holes that do not conduct. In particular, techniques using photosensitive resins are used.

On the other hand, recent advances in technology have made it necessary to increase the density of circuits, and circuit boards are also required to accommodate this. Conventional methods cannot meet this demand for higher density. JP-A-50-155964 discloses a method of forming a mesh resist pattern by screen printing, but with this method, it is difficult to form a high-density wiring pattern with a line width of 0.2 mm or less. . Also, JP-A-54-18
The method using a photosensitive film described in Publication No. 732, etc. has disadvantages in that it lacks ability to follow irregularities and scratches on the conductive film of a circuit board, and lacks reliability as a resist due to non-uniform curing due to oxygen. Furthermore, since the circuit pattern is printed through the base film, a line width of 0.15 mm is the limit in forming a high-density wiring pattern. In addition, it requires a base film and a protective film in addition to the photosensitive resin layer, and is extremely expensive.

(Means for solving the problem) What is important for achieving high density is that etching does not erode the parts necessary for the circuit, and for this purpose, uniform application of the photosensitive resin and high adhesiveness are required. is required. The present invention solves this problem by employing electrodeposition coating.

That is, the present invention forms a photosensitive resin composition coating by electrodeposition on a circuit board having a conductive coating on the surface having no through holes or non-conducting through holes, and An etching resist having a circuit pattern is formed by exposing and developing the film through a negative or positive photomask having a circuit pattern on the film, and then the exposed conductive film is removed by etching, and then the photosensitive resin on the circuit pattern is removed. A method for manufacturing a circuit board is provided, the method comprising removing a composition film.

In the present invention, a circuit board having a conductive film on its surface that has no through hole or a through hole with no conduction includes an insulating substrate that has no through hole or a through hole with no conduction. This includes all structures whose surfaces are coated with a conductive film, regardless of their manufacturing method. The circuit board having such a structure may be any conventionally used circuit board. For example, using glass cloth as a base material,
It is obtained by applying copper foil to one or both sides of a laminate using epoxy resin as a binder.

The anionic and cationic negative photosensitive resin compositions used in the present invention are not particularly limited; refers to an anionic and cationic photosensitive resin composition in which the non-exposed portion can be eluted with a phenomenon liquid.

For example, the anionic negative photosensitive resin composition electrodeposition solution is composed of an organic polymer binder having carboxyl groups, an ethylenically unsaturated compound, and a sensitizer, and the carboxyl groups of the organic polymer binder are neutralized with a base. obtained by mixing and dispersing in water. Examples of the organic polymer binder having a carboxyl group include a copolymer of α, β-ethylenically unsaturated carboxylic acid and ethylene, α, β-
Copolymer of ethylenically unsaturated carboxylic acid and acrylic ester or methacrylic ester, α.

Copolymers of β-ethylenically unsaturated carboxylic acid and acrylonitrile and copolymers of α,β-ethylenically unsaturated carboxylic acid and styrene are used.

As other organic polymer binders having carboxyl groups, cellulose derivatives having carboxyl groups, chlorinated polyethylene having carboxyl groups, etc. are used. The ethylenically unsaturated compound is preferably one having 2@ or more unsaturated bonds because it is polymerized by light irradiation to form a crosslinked bond. Ethylenically unsaturated compounds having two or more unsaturated bonds include acrylic esters and methacrylic esters, such as polyethylene glycol diacrylate, methacrylate, trimethylolpropanoacrylate, methacrylate, and trimethylolpropane triacrylate. Examples include acrylate, trimethylolpropane trimethacrylate, and pentaerythritol triacrylate. As the sensitizer, known ones such as benzoin ethers, xanthones, acetophenone derivatives, etc. can be used. Examples of the base that neutralizes the carboxyl group of the organic polymer binder include amines such as ammonia, alkanolamine, and triethylamine.

The cationic negative photosensitive resin composition electrodeposition solution is composed of an organic polymer binder having a cationic group such as an amino group or an onium base, an ethylenically unsaturated compound, and a sensitizer. It is obtained by neutralizing the amino group with acid and dispersing it in water.

As the organic polymer binder having an amino group, a copolymer of acrylate or methacrylate having an amino group and one or more polymerizable monopolymers such as acrylic ester, methacrylic ester, styrene, butadiene, acrylonitrile, etc. is used. As the ethylenically unsaturated compound and the sensitizer, the same ones as those used in the anionic negative photosensitive resin composition can be used. Examples of acids that neutralize the amino groups of the cationic organic polymer binder include acetic acid, crotonic acid, and itaconic acid.

Further, although anionic and cationic positive photosensitive resin compositions are not particularly limited, they can be used to form a continuous film on the conductive film of a circuit board by electrodeposition, and the exposed portion of the film is Refers to anionic and cationic photosensitive resin compositions that can be eluted with a developer.

For example, an anionic positive photosensitive resin composition electrodeposition solution is produced by copolymerizing α,β-ethylenically unsaturated carboxylic acid and a polymerizable monomer having a hydroxyl group or an amino group, and then copolymerizing the hydroxyl group of the polymer, Or, after adding a quinonediazide compound to the amino group by an esterification reaction, the carboxyl group of the α,β-ethylenically unsaturated carboxylic acid is neutralized with an alkali,
Obtained by dispersing in water. In addition, the cationic positive photosensitive resin composition electrodeposition solution is prepared by copolymerizing a polymerizable monomer having an amino group and a polymerizable monomer having a hydroxyl group, and then copolymerizing the hydroxyl group and/or the hydroxyl group of the copolymer. After partially adding a quinonediazide compound to the amino groups through an esterification reaction, the remaining amino groups in the copolymer are neutralized with acid,
Obtained by dispersing in water.

α used in the synthesis of anionic positive photosensitive resin composition
, β-ethylenically unsaturated carboxylic acids include maleic acid, fumaric acid (meth)acrylic acid, etc., and polymerizable monomers having a hydroxyl group or an amino group include:
Quinonediazide compounds used for esterification include 0-naphthoquinone diandosulfonyl chloride and 0-benzo Examples include, but are not limited to, quinonediazide sulfonyl chloride. Polymerizable monopolymers having amino groups used in the synthesis of cationic positive photosensitive resin compositions include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, diethylaminopropyl (meth)acrylamide, and γ-aminopropyl (meth)acrylate. Polymerizable monomers with hydroxyl groups include γ-hydroxystyrene, and quinonediazide compounds used for esterification include 0-naphthoquinonediazide sulfonyl chloride and 0-benzoquinonediazide sulfonyl chloride. Examples include, but are not particularly limited to.

In the anionic positive photosensitive resin composition, α, β-
The copolymerization ratio of ethylenically unsaturated carboxylic acid and a polymerizable monomer having a hydroxyl group or an amino group must be adjusted depending on the copolymerization components and the molecular weight of the copolymer, and the water dispersibility after alkali neutralization and Selection is made taking into account elution properties and resolution during development. Usually, the molar ratio is preferably in the range of 1/9 to 9/1.

If the copolymerization ratio is greater than 9 moles of α,β-ethylenically unsaturated carboxylic acid to 1 mole of polymerizable monomer having a hydroxyl group or an amino group, the carboxyl in the exposed area and the non-exposed area If the molar ratios of the groups are too close, a problem may arise in that unexposed areas are eluted during development, resulting in a decrease in resolution.

Conversely, if the molar ratio of carboxylic acid is less than 1 mole of α,β-ethylenically unsaturated carboxylic acid to 9 moles of a polymerizable monomer having a hydroxyl group or an amino group, water dispersion after alkali neutralization There may be problems with the properties and electrodepositivity. The weight average molecular weight of the copolymer varies depending on the components of each monomer to be copolymerized and the copolymerization ratio, and depends on the water dispersibility after alkali neutralization, the tackiness of the electrodeposited film, the elution property during development, and the resolution. , 1000 to 2, taking into account the acid resistance of the resist film during conductive film etching.
Preferably, a range of 00,000 is selected. In the cationic positive photosensitive resin composition, the copolymerization ratio of the polymerizable monomer having an amino group and the polymerizable monomer having a hydroxyl group needs to be adjusted depending on the copolymerization components and the molecular weight of the copolymer. The selection is made taking into consideration the acid resistance of the resist film, especially when etching the conductive film. Usually, the molar ratio is preferably in the range of 1/9 to 9/l. If the molar ratio of the polymerizable monomer having an amino group exceeds this range, problems such as swelling and dissolution of the resist film may occur during etching of the conductive film. If the amount is less than this range, problems may arise in water dispersibility and electrodepositivity after acid neutralization. The molecular weight of the copolymer varies depending on the components of each monomer to be copolymerized and the copolymerization ratio, and depends on the water dispersibility after acid neutralization, the adhesion of the electrodeposited film, the dissolution during development, resolution, and conductivity. 1,000 to 20, taking into account the acid resistance of the resist film during etching of the resist film.
Preferably, a range of 0,000 is selected.

Coloring agents such as waxes, fillers, and dyes may be added to these photosensitive resin compositions as necessary. A general method may be used for electrodeposition on the circuit board.

For example, a circuit board having a conductive coating on a surface having no through holes or having through holes with no conduction is placed in an electrodeposition bath made of an aqueous dispersion of an anionic photosensitive resin composition. The anionic photosensitive resin composition is deposited on the circuit board by immersing the circuit board in the bath, connecting the positive electrode to the circuit board and the negative electrode to the bath wall, and applying a direct current.
Once dry, a continuous film is formed. In the case of an aqueous dispersion of a cationic photosensitive resin composition, the connection of the positive and negative electrodes may be reversed from that in the case of an anionic composition. In the case of the negative photosensitive resin composition of the thus obtained electrodeposited film, it is applied through a negative photomask having a circuit pattern, and in the case of the positive photosensitive resin composition, it is applied through a positive photomask having a circuit pattern. each exposed to ultraviolet light. For a negative photosensitive resin composition, after cross-linking and curing the photosensitive resin composition in the exposed areas of the mask, if it is developed with an alkali or an appropriate solvent, the unreacted composition in the non-exposed areas will be eluted. An etching resist having an etching resist is formed on a circuit board. On the other hand, in the positive photosensitive resin composition, the quinone diazide group in the exposed area is photodecomposed and changes to indenecarboxylic acid via a ketene compound. Therefore, when this is developed with an alkaline aqueous solution, salts are formed in the exposed areas and eluted. The unexposed area does not change if it is anionic, but if it is cationic,
Undecomposed quinone diazide groups undergo an azo coupling reaction between cationic copolymer molecules through the intervention of an alkaline developer, and an etching resist with a circuit pattern with significantly improved acid resistance and alkali resistance is formed on a circuit board. Ru.

Next, the circuit board on which the etching resist having a circuit pattern has been formed is treated with an etching solution such as ferric chloride or cupric chloride, and after the exposed conductive film is etched away, the etching resist remaining on the conductive circuit pattern film is removed. The electrodeposited film is removed using an alkali or an appropriate solvent. The method of manufacturing a circuit board according to the present invention that does not have through holes or has through holes that are not conductive is a conventional method using screen printing or a method using a photosensitive film. Compared to the conventional method, it is possible to form a high-density wiring pattern with a line width of about 0.1 m+n, and the manufacturing method is simple, highly reliable, and highly economical.

Embodiments of the method of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 shows a circuit board consisting of an insulating substrate 1 whose surface is coated with a conductive film 2 and has through holes 3 with no conduction.

80 parts by weight of an organic polymer binder made by copolymerizing methacrylic acid, styrene, and ethyl acrylate at a molar ratio of 3:2:5 and a weight average molecular weight of 150.000, 5 parts by weight of microcrystalline wax, 2.2-dimethoxy-2 - An anionic negative photosensitive resin composition consisting of 0.5 parts by weight of phenylacetone phenone and 14.5 parts by weight of trimethylolpropane triacrylate was diluted with ethylene glycol monobutyl ether to a nonvolatile content of 80%, and 0.6 equivalents were obtained. It was neutralized with monoethanolamine, and an electrodeposition solution with a non-volatile content of 10% was prepared with pure water.

Next, the entire circuit board shown in Figure 1 is immersed in this electrodeposition solution, the positive electrode is connected to this circuit board, the negative electrode is connected to the electrodeposition solution container, and a DC voltage of 300V is applied to The photosensitive resin composition was applied for 1 minute to deposit about 15μ of the photosensitive resin composition on the conductive film of the circuit board, and then washed with water and dried in an oven at 100°C for 5 minutes to form the photosensitive resin composition film 4. (Figure 2). Next, a negative type photomask 5 having a circuit pattern is brought into close contact with the photosensitive resin composition film 4, and exposed to light using a high-pressure mercury lamp (FIG. 3). Then pH 11
The photosensitive composition film in the non-exposed area was eluted with an aqueous sodium carbonate solution and developed (FIG. 5). Next, the exposed conductive film 2 was removed by etching with a ferric chloride solution (Figure 6).
. Finally, the photosensitive resin composition film 4 on the circuit pattern is removed with trichloroethane to obtain the desired line width of 0 and 1 m.
A circuit board of m was obtained (Fig. 7).

Example 2 The electrodeposition solution in Example 1 was prepared using a molar ratio of N,N-diethylaminoethyl methacrylate to styrene and ethyl acrylate of 3:2:5, and a weight average molecular weight of ioo, ooo.
Organic polymer binder copolymerized with 80 parts by weight, microcrystalline wax 5 parts by weight, 2.2-dimethoxy-2-phenylacetonephenone 0.5 parts by weight, trimethylolpropane triacrylate 14.5 parts by weight.
A cationic negative photosensitive resin composition consisting of parts by weight is diluted with ethylene glycol monobutyl ether to reduce the non-volatile content to 80%.
%, neutralized with 0.5 equivalents of acetic acid, and adjusted to a non-volatile content of 10% with pure water.The entire circuit board shown in Figure 1 was immersed in this circuit board. The negative electrode was connected to the positive electrode to the electrodeposition liquid container, and a DC voltage of 300 V was applied for 2 minutes to deposit about 20 μ of the photosensitive resin composition on the conductive film of the circuit board, and then washed with water. It was dried in an oven at 100° C. for 5 minutes to form a photosensitive resin composition film 4 (FIG. 2). Next, this photosensitive resin composition coating 4
A negative photomask 5 having a circuit pattern is placed on top and exposed using a high pressure mercury lamp (FIG. 3). Next, the photosensitive composition film in the non-exposed area was eluted with trichloroethane and developed (FIG. 5). The exposed conductive film 2 was removed by etching with a ferric chloride solution (FIG. 6). Finally, the photosensitive resin composition coating 4 on the circuit pattern was removed with methylene chloride to obtain a circuit board with the desired line width of 0.08+nm (No. 7
figure).

Example 3 The electrodeposition solution in Example 1 was prepared using methacrylic acid and parahydroxystyrene in a molar ratio of 1:2 with a weight average molecular weight of 115.0.
After copolymerizing 0-naphthoquinone-(1,
2)-Diazido-(2)-sulfonyl chloride (5
) was reacted in an amount sufficient to esterify 100% of the hydroxyl groups of parahydroxystyrene, and the resulting anionic positive photosensitive resin composition was diluted with ethylene glycol monobutyl ether to a nonvolatile content of 75%. Neutralize with 7 equivalents of monoethanolamine and reduce the non-volatile content to 10% with pure water.
Instead of the one prepared in Figure 1, the entire circuit board shown in Figure 1 was immersed, the positive electrode was connected to the circuit board, the negative electrode was connected to the metal container of the electrodeposition solution, and a DC voltage of 300 V was applied for 1 minute. After depositing about 20μ of an anionic positive photosensitive resin composition on the conductive coating 2 of the circuit board, washing with water,
A positive photosensitive resin composition film 4 was formed by drying in an oven at 0° C. for 5 minutes (FIG. 2). Next, a positive photomask 6 having a circuit pattern was brought into close contact with the positive photosensitive resin composition film 4, and exposed to light using a high-pressure mercury lamp (fourth
figure). Next, the positive photosensitive resin composition coating on the exposed area was eluted in an aqueous sodium carbonate solution adjusted to a pH of 10 at a temperature of 20° C. or lower (FIG. 5).

Next, the exposed conductive film 2 was removed by etching with a ferric chloride solution (FIG. 6). pH 1 containing 20% ethylene glycol monobutyl ether, finally adjusted to 55°C.
The positive photosensitive resin composition coating 4 on the circuit pattern is removed in an aqueous sodium carbonate solution of 0.1 to a desired line width of 0.
A circuit board of 0.08+nm was obtained (FIG. 7).

Example 4 The electrodeposition solution in Example I was copolymerized with N,N-diethylaminoethyl methacrylate and parahydroxystyrene at a molar ratio of 3:7 to a weight average molecular weight of 20,000, and then O-naphthoquinone-(1 ,2)-Diazide-(2)-
Sulfonyl chloride (5) is reacted with an amount sufficient to esterify 60% of the hydroxyl groups of rose hydroxystyrene, and the resulting cationic positive photosensitive resin composition is diluted with ethylene glycol monobutyl ether to reduce the non-volatile content to 75%.
%, neutralized with 0.5 equivalent of acetic acid, and prepared with pure water to a non-volatile content of 10%.The entire circuit board shown in Figure 1 was immersed, and the negative electrode was placed on the circuit board. After connecting a positive electrode to a metal container and applying a DC voltage of 300 V for 2 minutes, a cationic positive photosensitive resin composition of about 15 μm was deposited on the conductive coating 2 of the circuit board. , washing with water 1
It was dried in an oven at 20° C. for 5 minutes to form a positive photosensitive resin composition film 4 (FIG. 2). Next, a positive photomask 6 having a circuit pattern was brought into close contact with the positive photosensitive resin composition membrane 4 and exposed to light using a high-pressure mercury lamp (FIG. 4). Next, the positive photosensitive resin composition film in the exposed area was eluted in an aqueous sodium hydroxide solution adjusted to a temperature of 40°C and a pH of 13, and then developed (FIG. 5). Next, the exposed conductive film 2 was removed with a cupric chloride aqueous solution (6th
figure). Finally, remove the positive photosensitive resin composition film 4 on the circuit pattern with trichloroethane to obtain the desired line width of 0.
．． A circuit board of 0.09 mm was obtained (Figure 7).

[Brief Description of the Drawings] Figures 1 to 6 are cross-sectional views of intermediate products in each step for explaining the circuit board manufacturing method of the present invention, and Figure 7 is a cross-sectional view of the circuit board obtained by the method of the present invention. FIG. October 28, 1985 Patent Application No. 209294 of 1985 2. Name of the invention Method for manufacturing a circuit board 3. Relationship with the case of the person making the amendment Patent applicant 4. Agent 6. Subject of amendment Column 7 of “Detailed Description of the Invention” of the specification
Contents of the amendment (1) In the first line of page 13 of the specification, the phrase "unreacted composition" is corrected to "unreacted composition." (2) On page 14, the last line 4 to the last line 3, "phenylacetonephenone" is corrected to "phenolacetophenone." (3) On page 16, line 8, "acetonephenone" is corrected to "acetophenone."that's all

Claims (1)

[Scope of Claims] 1. A photosensitive resin composition coating is formed by electrodeposition on a circuit board having a conductive coating on the surface and having no through holes or non-conductive through holes, and The conductive resin composition film is exposed to light through a photomask having a circuit pattern, and developed to form an etching resist having a circuit pattern.Then, the exposed conductive film is removed by etching, and the photosensitive resin on the circuit pattern is removed. A method for manufacturing a circuit board, comprising removing a composition film. 2. The method according to item 1, wherein the photosensitive resin composition is an anionic negative photosensitive resin composition. 3. The method according to item 1, wherein the photosensitive resin composition is a cationic negative photosensitive resin composition. 4. The method according to item 1, wherein the photosensitive resin composition is an anionic positive photosensitive resin composition. 5. The method according to item 1, wherein the photosensitive resin composition is a cationic positive photosensitive resin composition.