JPS6318692A - Manufacture of printed wiring board - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a printed wiring board. More specifically, the present invention relates to a method of manufacturing a printed wiring board in which a wiring pattern is formed by electroless plating using a photoresist.

(Prior art) Conventionally, the main method for manufacturing printed wiring boards has been to use a copper-clad laminate and remove copper from areas other than the wiring pattern by etching (referred to as the etched foil method). However, the method of directly forming wiring patterns on an insulating laminate by electroless plating without using a copper-clad laminate (called the additive method) is uneconomical due to the removal of unnecessary copper. It has recently attracted attention due to its low manufacturing cost. However, since the deposition rate of electroless steel plating is very slow, it takes a long time (usually 5 to 60 hours).

High temperature (usually 60-80℃), high alkalinity (usually pH
11-13.5) Plating generally requires immersion, and a resist for electroless plating that can withstand such severe conditions is required.

Traditionally, resists for this purpose are screen-printed with an ink containing epoxy resin and a hardener as the main ingredients.

Although it is formed by thermal curing, printing limits the dimensional accuracy of lines, so it has been difficult to produce printed wiring boards with high-density patterns using the additive method. Photoresists are suitable for forming high-density patterns, and a proposal for a photoresist for additive methods was published in 1973-
43468 Publication, tVf Publication No. 54-770, Japanese Patent Publication No. 58-199341, Japanese Patent Publication No. 59-1243
This is disclosed in Japanese Patent Publication No. 4, Japanese Unexamined Patent Publication No. 101532/1980, and the like. However, when mass-producing printed wiring boards using the photoadditive method using conventionally proposed photoresists or photoresists already on the market, a portion of the photoresist composition gradually disappears into the electroless plating bath. There was a problem in that the plating bath was gradually contaminated during the melting process and the physical properties of the electroless plated steel to be deposited were deteriorated.

Since the deterioration of the physical properties of copper is fatal to the reliability of printed wiring boards, - the tamping bath used in cars cannot be reused continuously;
It was not suitable for mass production.

(Purpose of the invention) The object of the invention is based on a photoadditive method.

It is an object of the present invention to provide a method for manufacturing a highly accurate printed wiring board with good physical properties of plated steel. Another purpose is to provide a manufacturing method that is suitable for mass production.

(Structure of the Invention) The present invention provides (1) on the surface of a substrate on which electroless plated copper is to be deposited, (a) (b) at least one terminal methacryloyl group and a hydrogen atom in one molecule; One or more unsaturated compounds 5 to 9 that do not have a directly covalently bonded nitrogen atom
A photopolymerizable compound consisting of 9% by weight and 1% by weight and (b) an unsaturated compound with at least 1 stroke having at least one terminal acryloyl group and no nitrogen atom directly covalently bonded to a hydrogen atom in the 9 molecule. (b) 0 to 400 parts by weight of a linear polymer compound that does not have a nitrogen atom directly covalently bonded to a hydrogen atom in the molecule; and fc) a sensitizer that generates free radicals by active light. or (and) step (2) of forming a layer of a photosensitive resin composition containing 0.5 to 20 parts by weight of a sensitizer system.
(3) forming a negative pattern of the photosensitive resin composition on the surface of the substrate by imagewise active light irradiation and development; and (3) using the negative pattern of the photosensitive resin composition on the surface of the substrate as a plating resist. The present invention relates to a method for manufacturing a printed wiring board, which includes a step of forming a wiring pattern by electroless steel plating.

The method of manufacturing a printed wiring board proposed by the present invention will be described in detail below.

The method of manufacturing a printed wiring board proposed by the present invention includes the step of forming a layer of a photosensitive resin composition on the surface of a substrate on which electroless plated steel is to be deposited on the required portions.

As the substrate, a laminated board of paper phenol, glass epoxy, etc., an iron enamel board, a board with a metal core such as a board with an epoxy resin insulating layer formed on both sides of an aluminum board, etc. can be used. These substrates can also be immersed in a solution containing a plating catalyst after drilling the holes to apply the plating catalyst to the inner walls of the through holes. As such a plating catalyst solution, 1 Hitachi Chemical's ■M Sensitizer H8-101B or the like can be used. To ensure good adhesion of the catalyst to the surface of the substrate.

Alternatively, it is preferable to apply an adhesive layer to improve the adhesion of the deposited electroless plated copper to the substrate.

As the adhesive, those known as additive adhesives such as phenol-modified nitrile rubber adhesives can be used. A compound that serves as a plating catalyst can also be included in the adhesive. In order to improve the adhesion of the plating catalyst or the adhesion of the deposited electroless plated steel, it is preferable to roughen the surface of the adhesive layer before the electroless plating treatment. As a roughening method, there is a method of immersion in an acidic solution containing sodium dichromate, chromium chloride, etc., but as is known, if the roughening process is performed before the electroless copper plating process, the photosensitivity described in the arrow will be reduced. It may be done before forming the resin composition layer or after forming the resist pattern.

In addition, as a board, there are two-paper phenol, glass epoxy, etc. laminated boards, iron enamel boards, boards with epoxy resin insulating layers formed on both sides of aluminum boards, boards with metal cores, etc., with copper foil pasted on both sides. A stretched substrate may also be used.

After drilling, these substrates can be immersed in a solution containing a plating catalyst to apply the plating catalyst to the inner walls of the through holes.

In addition, to improve the adhesion between the plating resist and copper,
The surface of the copper foil can be etched using an acidic aqueous solution containing an oxidizing agent such as cupric chloride.

When using a copper-clad substrate, a negative pattern of the photosensitive resin composition described below is formed on the copper foil.

A wiring pattern is formed on this pattern-free area by electroless copper plating, the resist is removed, and then the copper foil between the circuits is removed by etching to obtain a printed wiring board. In addition, after forming a wiring pattern by etching the copper foil in advance, a negative pattern of the photosensitive resin composition described in the arrow is formed, excluding through holes and necessary land areas, and electroless copper plating is applied to the areas without this pattern. A printed wiring board can be obtained by forming a wiring pattern.

The photosensitive resin composition used in the present invention includes (a) one or more unsaturated compounds having at least one terminal methacryloyl group and having no nitrogen atom directly covalently bonded to a hydrogen atom within the molecule; % and (b) one or more unsaturated compounds having at least one terminal acryloyl group and no nitrogen atom directly covalently bonded to a hydrogen atom in one molecule 95-1
% by weight of a photopolymerizable component as an essential component. It has at least one terminal methacryloyl group of (a).

Examples of unsaturated compounds that do not have a nitrogen atom directly covalently bonded to a hydrogen atom in the molecule include trimethylolpropane, trimethylolethane, pentaerythritol, dipentaerythritol, 1,6-hexanediol, propylene glycol, and tetraethylene glycol. , methacrylic acid esters of polyhydric alcohols such as dibrome neopentyl glycol, dicyclopentenyloxyethyl methacrylate, tetrahydrofurfuryl methacrylate, benzyl methacrylate, and the like.

(b) It has at least one terminal acryloyl group.

Examples of unsaturated compounds that do not have a nitrogen atom directly covalently bonded to a hydrogen atom in the molecule include trimethylolpropane, trimethylolethane, pentaerythritol, dipentaerythritol, 1,6-hexanediol, propylene glycol, and tetraethylene glycol. , acrylic esters of polyhydric alcohols such as dibrome neopentyl glycol, dicyclopentenyloxyethyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, and the like.

Detailed studies by the present inventors have revealed that the inclusion of nitrogen atoms often leads to a decrease in the physical properties of copper, and in particular, the presence of nitrogen atoms directly covalently bonded to hydrogen atoms such as -class and secondary amino groups, amide groups, urethane groups, etc. It has been revealed that the inclusion of a group containing a nitrogen atom causes a significant deterioration in the physical properties of copper. The inclusion of groups containing an oxygen atom directly covalently bonded to a hydrogen atom, such as a hydroxyl group or a carboxyl group, is also often undesirable;
Particularly preferred examples of the unsaturated compound include trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate, and 1,6-hexanethiol dimethacrylate. Also.

Although the reason is unknown, compared to when the photopolymerizable component is only an acrylate unsaturated compound, the contamination of the plating bath is reduced by using a methacrylate unsaturated compound in combination or alone, and the physical properties of copper are significantly improved. It became clear.

From the viewpoint of the photosensitivity of the photosensitive resin composition and the physical properties of the plated steel, the component (a) is 5 to 99% by weight, and the component (b) is 95 to 99% by weight.
It is said to be in the range of 1% f%, but the more preferable range is (a)
The content of the component is in the range of 20 to 95% by weight, and the content of the component in the middle is in the range of 80 to 5% by weight.

1 Photosensitive resin composition used in the present invention has a linear polymer that does not have any of the hydrogen atoms and directly covalently bonded hydrogen atoms in 9 molecules for a total of 100 parts of the above components (a) and (b). Contains 0 to 400 parts of a molecular compound.

If the content of the linear polymer compound exceeds 400 parts by weight, the photosensitivity will be low and it will not be practical. An example of a linear polymer compound that does not have a nitrogen atom directly covalently bonded to a hydrogen atom in its molecule is methyl methacrylate.

Vinyl polymers obtained by polymerizing or copolymerizing vinyl monomers such as ethyl acrylate, tetrahydrofurfuryl methacrylate, methacrylic acid, 2-hydroxyethyl methacrylate, benzyl methacrylate, styrene, vinyltoluene, vinyl acetate, and butadiene. compound, ethylene glycol.

Examples include polyester-based polymer compounds obtained by condensing dihydric alcohols such as cyfurobylene glycol and 1,6-hexanediol with divalent acids such as maleic acid and phthalic acid. It is preferable to use a linear polymer compound having a tetrahydrofurfuryl group in its side chain since it improves the physical properties of plated copper.

In the case where the formation of a layer of a photosensitive resin composition described later is a method of laminating photosensitive elements.

In terms of film-forming properties, linear polymer compounds that do not have a nitrogen atom directly covalently bonded to a hydrogen atom in the molecule are
) Based on 100 parts by weight of photopolymerizable component.

It is preferably contained in an amount of 20 to 400 parts by weight.

The photosensitive resin composition used in the present invention contains 0.5 parts by weight of a sensitizer or (and) a sensitizer system that generates free radicals by actinic light per 100 parts by weight of the photopolymerizable component (a). ~
Contains 20 parts by weight. Sensitizer or (and) sensitizer system is 0
If it is less than 65 parts by weight, the photosensitivity will be low, and if it exceeds 20 parts by weight, the shape of the negative pattern formed will be poor.

Sensitizers that can be used include substituted or unsubstituted polynuclear quinones 2, such as 2-ethylanthraquinone, 2-1-
Butylanthraquinone, octamethylanthraquinone,
Ketoaldonyl compounds such as diacetyl and benzyl, such as 1,2-benzanthraquinone and 2,3-diphenylanthraquinone.

α-ketaldonyl alcohols and ethers such as benzoin and biparone, α-hydrohydrocarbon-substituted aromatic acyloins such as α-phenyl-benzoin, α, α-jethoxyacetophenone, etc., benzophenone, 4.4'-
All aromatic ketones such as bisdialkylaminobenzophenone can be mentioned, and these may be used alone or in combination. Sensitizer systems that can be used include 2.4.5-) Realyl imidazole dimer and 2-mercaptobenzoquinazole;
Examples include combinations with leuco crystal violet, tris(4-diethylamino-2-methylphenyl)methane, and the like. Additionally, additives can be used which do not have photoinitiating properties by themselves, but which, when used in combination with the above-mentioned substances, result in a sensitizer system with better photoinitiating performance as a whole. For example, there are tertiary amines such as triethanolamine for benzophenone.

The photosensitive resin composition used in the present invention may further contain other subsidiary components. Vi as a bicomponent
These include thermal polymerization inhibitors, dyes, pigments, coating property improvers, etc., and selection thereof is made based on the same considerations as those for ordinary photosensitive resin compositions.

The method of manufacturing a printed wiring board proposed by the present invention necessarily includes the step of forming a layer of the photosensitive resin composition described in detail above on the surface of the substrate on which electroless plated copper is to be deposited on the required portions. The step of forming a layer of a photosensitive resin composition on the surface of an insulating substrate on which electroless plated copper is to be deposited can be carried out by a conventional method. For example, methyl ethyl ketone photosensitive resin composition.

KEl! is uniformly dissolved or dispersed in a solvent such as toluene or methylene chloride, and then applied to the surface of an insulating substrate on which electroless plated copper is to be deposited using a dip coating method, a flow coating method, etc. This is done by wiping and drying with a solvent. without directly applying a solution of the photosensitive resin composition onto the substrate.

Knife coat this solution onto the support film.

After coating and drying by a known method such as a roll coating method to produce a photosensitive element having a layer of a photosensitive resin composition on a support film, the photosensitive element is coated on an insulating substrate on which electroless plated steel is to be deposited. A layer of the photosensitive resin composition can also be formed on the surface of the substrate by heating and pressurizing the layer by a known method. As the support film, known films such as polyester film, polypropylene film, polyimide film, polystyrene film, etc. can be used. The method using a photosensitive element is preferable because it is easy to make the coating thickness uniform and adhesives with low solvent resistance can also be used.

The method of manufacturing a printed wiring board proposed by the present invention is to apply a negative pattern of a photosensitive resin composition on the surface of an insulating substrate, which is to be irradiated with imagewise active light and then developed to deposit electroless plated copper on the required areas. It always includes the step of forming. Irradiation of imagewise active light can be carried out by using a light source such as an ultra-high-pressure mercury lamp or a high-pressure mercury lamp, and by emitting imagewise KB light through a negative mask.

This can also be done by image-wise scanning a laser beam focused on a minute cross-sectional area of the trench. Development can be carried out by immersing a substrate having a layer of a photosensitive resin composition imagewise irradiated with actinic light in a developer such as 1.1.1-) dichloroethane or by spraying the developer.

It is preferable to further re-irradiate the photosensitive resin composition with active light after development, as this further advances photocuring of the photosensitive resin composition, improves plating resistance, and further reduces contamination of the plating bath. Re-irradiation of the activation light can be performed by irradiating the entire surface of the substrate using a light source such as an ultra-high pressure mercury lamp or a high-pressure mercury lamp.

The method for manufacturing a printed wiring board proposed by the present invention necessarily includes the step of forming a wiring pattern by electroless copper plating using the negative pattern of the photosensitive resin composition obtained by the above method as a plating resist.

Electroless plating solution includes copper salt, complexing agent, reducing agent and pH
A plating solution containing 100% of plating agent can be used.

Examples of copper salts include copper sulfate, copper nitrate, and copper formate.

Cupric chloride or the like can be used. As the complexing agent, for example, ethylenediaminetetraacetic acid, N-hydroxyethylethylenediaminetriacetic acid, N, N, N', N'-tetrakis-2-hydroxyglobylethylenediamine, Rochelle salt, etc. can be used. Formalin is preferred as the reducing agent. Further, as the pH adjuster, alkali hydroxide is usually used, and examples thereof include sodium hydroxide and potassium hydroxide. Furthermore, various additives may be added for the purpose of increasing the stability of the plating bath or improving the properties of the deposited copper metal. The plating bath conditions are based on the stability of the plating bath, the characteristics of the deposited copper metal, etc., and the copper concentration is 1 to 1.
159/1. pH 10-13.5. Bath temperature 50-90
°C is preferred. In electroless copper plating, it goes without saying that a plating catalyst may be attached and/or activated if necessary.

After wiring pattern formation by electroless steel plating.

The negative pattern of the photosensitive resin composition used as a plating resist may be peeled off and removed.

This may be left as is as a permanent resist.

After wiring pattern formation, the purpose is to protect the copper surface from oxidation, or to reduce contact resistance when that part becomes an electrical connection part.

The entire wiring pattern or a desired portion can be coated with solder using a solder leveler or the like, or gold plating, tin plating, etc. can be performed. Solder the copper surface.

A solder mask can be formed on the required portions of the substrate temporarily covered with metal such as gold or tin, or with the copper surface intact. This solder mask can also be used as a resist for coating only desired portions of the wiring pattern with solder or the like. The solder mask can be formed by printing and curing epoxy resin ink by screen printing or the like, or the entire solder mask can be formed with high precision using a photographic method. The printed wiring board manufactured in this way can be used in various ways using known methods, 9 for example, by soldering all electronic components.

The printed wiring board after electroless copper plating can also be used as an inner layer board of a multilayer printed wiring board.

(Example) Next, an example of the present invention will be shown. The present invention is not limited to the examples shown here. "Parts" in Examples and Comparative Examples indicate parts by weight.

Example 1-G 4
Part Benzophenone Part 3 Part 4.
4'-bis(diethylamino)benzophenone
0.1 part Victoria Pure Blue 0.01 part Methyl ethyl ketone 100 parts Using the apparatus shown in FIG. ~100℃ hot air convection dryer 11
Dry for 0 minutes. The thickness of the layer of the photosensitive resin composition after drying was about 35 μm. On the layer of the photosensitive resin composition, a polyethylene film 17 having a thickness of about 25 μm was further laminated as a cover film as shown in FIG. 1 to obtain a photosensitive element.

In FIG. 1, 5 is a polyethylene terephthalate film roll, 6, 7.8 Vi rolls, 9 is a knife, 12 is a polyethylene film roll, 13
．． 14 is a roll, and 15 is a photosensitive element winding roll.

On the other hand, adhesive whose main component is acrylonitrile butadiene rubber-modified phenolic resin (9 product number 777, manufactured by ACI Japan ■) was applied to both sides of a phenolic resin laminate (manufactured by Hitachi Chemical ■, LP-461F) with a thickness of 1.6 mm. After applying,
The adhesive is cured by heating at 160℃ for 110 minutes to a thickness of approximately 3.
A laminate with a 0 μm adhesive layer was obtained. Next, holes were drilled at required locations, and the surface of the adhesive layer was roughened by immersing it in a roughening solution containing chromic anhydride and sulfuric acid. Next, we use Hitachi Chemical Co., Ltd. as a catalyst for chemical plating.

It was immersed in an acidic aqueous solution containing sensitizer H8l0IB for 10 minutes, washed with water, treated with 3.6% by weight diluted hydrochloric acid for 5 minutes, washed with water, and then dried at 120° C. for 20 minutes.

Next, this was cut into 16 cm x 10 cm to prepare a test board.

The photosensitive elements obtained above were laminated on both sides of the 30 test substrates according to a conventional method, and exposed to 400 mJ/C using an ultra-high pressure mercury lamp through a test negative mask shown in Fig. 2.
21 is the opaque part of the negative mask, 22 is the transparent part of the negative mask, and the units of numbers are units of exposure. After heating at 80°C for 5 minutes and leaving at room temperature for 20 minutes, the support was removed. Peel off the polyester film that is the body film.

1,1.1-) Spray development was carried out using dichloroethane for 70 seconds, and the film was dried at 80°C for 10 minutes. after that.

The entire surface of the test substrate was reirradiated with ultraviolet light in an amount of 3 J/cII+2 using a high-pressure small silver lamp.

Thirty test substrates on which negative patterns of the photosensitive resin composition were formed in this way were immersed in a chemical steel plating solution with the following composition at 70°C for 12 hours to perform electroless steel plating, and the areas without negative patterns were Copper was deposited to a thickness of about 30 μm. At this time, a 16 cm x 10 stainless steel plate polished with No. 500 abrasive paper was sensitized with a commercially available catalyst solution (manufactured by Hitachi Chemical Co., Ltd., H8101B) and electroless steel plated at the same time. Gently peel off the copper foil from the stainless steel plate.

A specimen for a tensile test was prepared by cutting into a 1 cm width.

(Chemical steel plating solution composition) Copper sulfate pentahydrate 10 g/l Ethylenediaminetetraacetic acid 30 g/V37 thiformin
3ml/1pH (sodium hydroxide adjustment)
IZ5 polyethylene glycol (molecule 160
0) 20rnl/1 2.2'-dipyridyl 30111g/1
On all 30 test boards, a patterned copper pattern was obtained that reproduced with high precision the pattern of the negative film used. In addition, using copper foil plated on a stainless steel plate, ■ Autograph DSS-5000 manufactured by Shimadzu Corporation was used with a chuck interval of 50 mm.

A tensile test was conducted at a tensile speed of 2 mm/min, and the mechanical properties of the copper were measured, and the elongation rate was 9.2%, and the number of bends possible was 6 times, which were good.

Example 2 46 parts of trimethylolpropane trimethacrylate and 4 parts of trimethylolpropane triacrylate of Example 1
Example 1 was repeated, except that 25 parts of trimethylolpropane trimethacrylate and 25 parts of trimethylolpropane were used instead of 25 parts of acrylate. A highly accurate plated copper pattern is obtained, and the elongation rate of copper is 7.5.
H. The bendable opening e was 1.5 times, which was good.

Example 3 46 parts of trimethylolpropane trimethacrylate of Example 1 and 4 parts of trimethylolpropane triacrylate
1 part of trimethylolpropane trimethacrylate 2(1,2,2'-bis(4-methacryloΦsidiethoxyphenyl)propane and 10 parts of KAYARAD"R-
The same procedure as in Example 1 was conducted except that 20 parts of 604 (acrylate monomer, manufactured by Nippon Kakei ■) was used. A highly accurate pattern of plated copper was obtained, and the copper elongation rate was 10.1%, and the number of bends possible was 6, which was good.

Example 4 46 parts of trimethylolpropane trimethacrylate of Example 1 and 4 parts of trimethylolpropane triacrylate
30 parts of dipentaerythritol hexamethacrylate, 10 parts of tetrahydrofurfuryl methacrylate
The same procedure as in Example 1 was conducted except that 10 parts of trimethylolethane triacrylate and 10 parts of trimethylolethane triacrylate were used. A highly accurate plated steel pattern was obtained, and the copper elongation rate was 9.5%, and the number of bends possible was 6 times, which was good.

Example 5 Benzophenone 3 parts Victoria Pure Blue 0. OJ part Toluene 50 parts Methyl ethyl ketone 50 parts The same procedure as in Example 1 was carried out except that a solution of the photosensitive resin composition having the above formulation was used. A highly accurate plated copper pattern was obtained, and the copper elongation rate was 87 inches, and the number of bends possible was 6, which was good.

Example 6 In place of 55 parts of methyl methacrylate/styrene/butadiene copolymer of Example 5, methyl methacrylate/tetrahydrofurfuryl methacrylate/methacrylic acid/2-
Hydroxyethyl methacrylate (82/15/l/2
Example 1 was repeated except that 55 parts of the copolymer (fi amount ratio) was used.

A highly accurate plated copper pattern was obtained, and the copper elongation rate was 8.
2% and could be bent 6 times, which was good.

Comparative Example 1 Trimethylolpropane trimethaf IJ L of Example 1
Example 1 was repeated except that 46 parts of trimethylolpropane triacrylate and 46 parts of trimethylolpropane triacrylate were used instead of 46 parts of trimethylolpropane triacrylate.

The physical properties of copper were not good, with an elongation rate of 3.2% and a bendable number of times of 3.

Comparative Example 2 46 parts of trimethylolpropane trimethacrylate of Example 1 and 4 parts of trimethylolpropane triacrylate
The same procedure as in Example 1 was carried out, except that 50 parts of urethane diacrylate obtained by reacting 1 mole of isophorone diisocyanate with 2 moles of 2-hydroxyethyl acrylate was used instead of 1 mole of isophorone diisocyanate.

The physical properties of the pot were not good, with an elongation rate of copper of 1.5% and the number of bends possible.

Comparative Example 3 46 parts of trimethylolpropane trimethacrylate of Example 1 and 4 parts of trimethylolpropane triacrylate
The same procedure as in Example 1 was carried out, except that 50 parts of urethane dimethacrylate obtained by reacting 1 mole of tolylene diisocyanate with 2 moles of 2-hydroxyethyl methacrylate was used instead of 1 mole of tolylene diisocyanate. The physical properties of copper were not good, with an elongation rate of 2.1% and a bendability of 1 time.

Example 7 20 parts of methyl ethyl ketone A solution of the above photosensitive resin composition was coated on 30 test substrates, the same as those used in Example 1, by dip coating and heated at 80°C.
and dried for 10 minutes. The thickness of the layer of the photosensitive resin composition after drying was approximately 20 μm. A 25 μm thick polyethylene terephthalate film was laminated thereon. The same procedure as in Example 1 was carried out except that the layer of the photosensitive resin composition was formed in this manner. A highly accurate plated steel pattern was obtained, and the copper elongation rate was 7.4%, and the number of bends possible was 5, which was good.

(Effects of the Invention) As shown in the Examples, by the method for manufacturing a printed wiring board according to the present invention, a highly accurate printed wiring board with good physical properties of plated copper can be obtained by an additive method.

In addition, since there is almost no contamination of the plating bath, mass production becomes possible.

It should be noted that the above are merely examples of the present invention, and various modifications and usage methods are naturally possible without departing from the spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a photosensitive element manufacturing apparatus used in Examples, and FIG. 2 is a diagram showing a test negative mask used in Examples. Explanation of symbols 5...Polyethylene terephthalate film Film < Extrusion L roll 13
．． 14... Roll 15... lle element winding roll 16...
- Polyethylene terephthalate film 17... Polyethylene film 21... Opaque part of negative mask 22... Transparent part of negative mask l Eyes Tz mouth

Claims (1)

[Claims] 1. (1) The surface of the substrate on which the electroless plated copper is to be deposited on the required portions has (a) (b) at least one terminal methacryloyl group, and hydrogen atoms in the molecule. one or more unsaturated compounds that do not have a nitrogen atom directly covalently bonded to
99% by weight and (b) at least 1 terminal acryloyl group.
(b) for 100 parts by weight of a photopolymerizable component consisting of 95 to 1% by weight of one or more unsaturated compounds having no nitrogen atom directly covalently bonded to a hydrogen atom in the molecule; 0 to 400 parts by weight of a linear polymer compound that does not have a nitrogen atom directly covalently bonded to a hydrogen atom; and (c) 0.5 to 20 parts by weight of a sensitizer or (and) a sensitizer system that generates free radicals by actinic light. Step (2) of forming a layer of a photosensitive resin composition containing parts by weight
forming a negative pattern of the photosensitive resin composition on the surface of the substrate by imagewise active light irradiation and development; and (3) plating the negative pattern of the photosensitive resin composition on the surface of the substrate with a resist. 1. A method for manufacturing a printed wiring board, comprising the step of forming a wiring pattern by electroless copper plating. 2. Claim 1, wherein the linear polymer compound (b) that does not have a nitrogen atom directly covalently bonded to a hydrogen atom in the molecule is a linear polymer compound that has a tetrahydrofurfuryl group in its side chain. A method for manufacturing a printed wiring board as described in Section 1. 3. The method for manufacturing a printed wiring board according to claim 1 or 2, wherein the step of forming a layer of the photosensitive resin composition is a method of laminating photosensitive elements. 4. The method for manufacturing a printed wiring board according to claim 1, 2, or 3, which includes the step of further irradiating with active light after development. 5. (a) An unsaturated compound having at least one terminal methacryloyl group and having no nitrogen atom directly covalently bonded to a hydrogen atom in the molecule is a compound that also does not have an oxygen atom directly covalently bonded to a hydrogen atom. Claim 1,
The method for manufacturing a printed wiring board according to item 2, 3, or 4.