JPH1140945A - Manufacture of multilayered printed board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a multilayered printed board using a photosensitive additive adhesive, which has high resolution, excels in plating solution resistance in a highly alkaline condition, has high bonding strength with plating copper, and has heat resistance. SOLUTION: In this manufacture, a double-sided copper-plated board is etched to form an inner layer circuit, and the surface of the inner layer circuit is roughened. After laminating a photosensitive additive adhesive film on both the planes or one plane of the inner layer circuit board, light is applied to harden the film. Then, the adhesive film irradiated with light is removed, and the board is heated and dried. The board is developed with alkaline aqueous solution to form a surface is viahole, and the surface of the photosensitive additive adhesive resin is smoothed by polishing. Then, an acid soluble filler exposed from the surface is dissolved by acid aqueous solution, and the photosensitive additive adhesive resin is chemically dissolved and roughened by an oxidizer. After performing electroless plating, electrolytic plating is performed, then etching a resist is applied, and a circuit is formed by etching.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer printed wiring board using a photocurable additive adhesive film for a printed wiring board.

[0002]

2. Description of the Related Art As a conventional method of manufacturing a multilayer printed wiring board, a circuit is first formed on a double-sided copper-clad board by etching, the circuit surface is roughened, and a glass cloth base material is impregnated with epoxy resin. In this process, one or more prepreg sheets that had been semi-cured were laminated, and a copper foil or a single-sided copper-clad board was further laminated thereon, followed by heat integration by a hot press. In this process, a glass cloth base material must be impregnated with epoxy resin and semi-cured once to make a prepreg sheet. there were. In addition, since the copper foil residual ratio of the patterned inner layer material differs, it is necessary to prepare various types of prepregs with different amounts of resin and melting behavior in order to adjust the interlayer thickness. Since a substrate is used, it is difficult and extremely costly to reduce the thickness of the interlayer.

[0003] In order to solve these problems, various techniques have been reported in which a glass cloth substrate is not used for an interlayer insulating layer. For example, there is a method using a thermosetting epoxy resin coating or film, a polyimide resin coating or film, a thermoplastic heat-resistant resin film, or a photocurable epoxy interlayer insulating film. In recent years, in order to increase the density, reduce the size, and reduce the weight of a multilayer printed wiring board, it has become necessary to provide not only fine circuit patterns but also surface via holes for conducting layers. When the surface via hole is machined with a mechanical drill, the hole machining with a diameter of about 300 μm is the limit, and when it is less than that, problems such as hole position accuracy and drill life will arise. When processed with excimer laser or carbon dioxide laser, about 50
Drilling of μm is possible, but the overlapping process cannot be performed as in the case of through through holes, so that the number of steps increases. Therefore, each material maker is energetically developing a photosensitive additive adhesive that can be developed.

[0004]

As in the conventional method, a prepreg is prepared by impregnating a glass cloth base material with an epoxy resin, hardening by heating and pressurizing by a press, and forming a surface via hole by a mechanical drill. However, there are problems that the cost is high due to the use of glass cloth, that the thickness cannot be made extremely thin, and that a fine pattern cannot be formed because a surface via hole is formed by a subtractive method and a mechanical drill is used. For this reason, the circuit formation by the additive method is advantageous for making the circuit finer.However, in the additive method for manufacturing substrates for consumer use, generally, a thermosetting additive adhesive is often used. JP-B-63-10752, JP-A-63-297571, JP-A-64-107571
No. 47095, JP-A-3-18096, etc., those which roughen the adhesive layer with an oxidizing agent are mentioned. The contents include a rubber component such as acrylonitrile-butadiene rubber, and a chromium-sulfuric acid aqueous solution as the oxidizing agent. To elute the rubber component and roughen the adhesive surface.

Further, an inorganic fine powder such as silica or calcium carbonate is dispersed in a resin matrix having excellent heat resistance such as an epoxy resin, a phenol resin or a melamine resin to form an adhesive, and the inorganic fine powder is used as a specific chemical. And a method of roughening the adhesive layer by selectively eluting the cured epoxy resin, as described in JP-A-1-29479. There is a method of dispersing resin fine powder and selectively eluting the epoxy resin fine powder with an oxidizing agent. However, when using these thermosetting additive adhesives, the surface via holes for further refinement must be machined with a mechanical drill, excimer laser, or carbon dioxide laser, making the hole diameter smaller and reducing man-hours. Can not be compatible.

On the other hand, as means for forming surface via holes by photoimaging, a method using an epoxy resin as a matrix and a cationic photoinitiator as a curing agent, a method using a phenol novolak type epoxy resin or a cresol novolak type epoxy as a matrix. Although there is a method using an acrylate-modified resin, etc., an organic solvent must be used for the developer, which is not preferable in terms of working environment. In addition, as an additive adhesive that can be developed with an aqueous alkali solution, one containing a carboxyl group-modified epoxy acrylate or a carboxyl group-modified phenol novolak type epoxy acrylate as a matrix and containing an inorganic or organic filler soluble in an acid or an oxidizing agent is used. is there. However, these have a problem that they are inferior in thick film processability and simultaneous processability on both sides because many liquid photosensitive resists are used.

Accordingly, an object of the present invention is to form a via hole with high accuracy by photoimaging by development using an alkaline aqueous solution, and to have a sufficient adhesive strength between the roughened surface of the adhesive and the plated copper. Yes, multi-layer printing by build-up using a photosensitive additive adhesive film that is sufficiently resistant to the electroless copper plating solution of the full additive method and has the heat resistance to withstand the temperature around 260 ° C of the soldering process It is an object of the present invention to provide a method for manufacturing a wiring board.

[0008]

In order to achieve the above object, a method for manufacturing a multilayer printed wiring board using a photosensitive additive adhesive film according to the present invention has excellent characteristics. And manufacturing a multilayer printed wiring board by a method having a specific process using the additive adhesive film. That is, in the present invention, first, the photosensitive additive adhesive film comprises the following components (a), (b),
(C), (d), (e) and (f). (A) a polyfunctional epoxy resin having an epoxy equivalent of 120 to 500, and (b) a phenol novolak obtained by condensing bisphenol A or F with formaldehyde under an acidic catalyst, wherein the phenolic novolak has a phenolic hydroxyl group content of 20 to 60.
% Modified bisphenol novolak, which has been reacted with glycidyl acrylate or glycidyl methacrylate,
(C) an epoxy acrylate or epoxy methacrylate compound, (d) a diluent comprising a polyfunctional photopolymerizable monomer, (e) a photopolymerization initiator, and (f) an acid-soluble filler.

The epoxy resin of component (a) used in the present invention is preferably a bisphenol A type (or F type) epoxy resin, and if the average molecular weight is more than 1,000, it is preferable in terms of developability using an aqueous alkali solution. Absent. The phenol novolak of the component (b) is obtained by reacting phenol novolak obtained by condensing bisphenol A or F with formaldehyde under an acidic catalyst, and acrylate or methacrylate having a glycidyl group. In order to obtain a highly accurate photosensitive additive adhesive which is photopolymerized and excellent in alkali developability, an epoxy group of an acrylate or methacrylate having a glycidyl group with respect to 1 equivalent of a hydroxyl group of phenol novolak is used.
2 to 0.6 equivalents are suitable. Glycidyl acrylate and glycidyl methacrylate are preferred due to their reactivity, availability and the like.

(C) The epoxy acrylate or epoxy methacrylate compound is not particularly limited, but is a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, a phenol novolak type epoxy compound, a cresol novolak. It is obtained by reacting an epoxy compound such as a type epoxy compound or an aliphatic epoxy compound with acrylic acid or methacrylic acid.

(D) Examples of the diluent comprising a polyfunctional photopolymerizable monomer include compounds having two or more acryloyl groups or methacryloyl groups in one molecule. For example, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate,
1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6
-Hexanediol dimethacrylate, glycerol diacrylate, neopentyl glycol diacrylate, bisphenol A diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate and the like. Preferred monomers are tri- or 4-functional trimethylolpropane triacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate having good developer resistance after photocuring.

(E) Photopolymerization initiators include benzophenones such as benzophenone, benzoylbenzoic acid, 4-phenylbenzophenone and hydroxybenzophenone, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether,
Benzoin alkyl ethers such as benzoin isobutyl ether, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t
-Butyl-trichloroacetophenone, acetophenones such as diethoxyacetophenone, thioxanthone,
Examples thereof include thioxanthones such as 2-chlorothioxanthone, 2-methylthioxanthone and 2,4-dimethylthioxanthone, and alkylanthraquinones such as ethylanthraquinone and butylanthraquinone. These may be used alone or as a mixture of two or more. The addition amount of this photopolymerization initiator is usually 0.1
It is used in the range of 10 to 10% by weight.

As the (f) acid-soluble filler, calcium carbonate is preferable, and 20 to 100% by weight of the resin.
It is used in the range of 50% by weight. When the content is less than 20% by weight, even if calcium carbonate on the surface of the adhesive after curing is dissolved by an acid, the concave portions are small and the roughened shape is not good, so that the adhesive strength with plated copper is reduced. In addition, if necessary, an ultraviolet inhibitor, a thermal polymerization inhibitor, a plasticizer, etc. can be added for storage stability.

The photosensitive additive adhesive film comprising these components has high resolution and excellent developability with an aqueous alkali solution. In particular, the solubility in an aqueous alkali solution depends on the phenolic hydroxyl group of the component (b). As described above, the photo-cured product in which the phenolic hydroxyl group remains becomes a cured product having poor alkali resistance, chemical resistance, and electrical properties, but the photosensitive additive adhesive film is cured after photo-curing and development. Is a resin composition mainly composed of a thermosetting reaction, and the post-heat treatment causes the epoxy resin of the component (a) to undergo a thermosetting reaction with the phenolic hydroxyl group in the component (b) to form a main skeleton excellent in required characteristics. To form. Therefore, the additive adhesive cured product can withstand electroless plating performed for a long time under high temperature and high alkaline conditions.

The present invention provides a method for manufacturing a multilayer printed wiring board comprising the following steps using the above-described photosensitive additive adhesive. (A) Etching a double-sided copper-clad board to form an inner layer circuit (B) a step of roughening the surface of the inner layer circuit, (C) a step of laminating the photosensitive additive adhesive film on both or one side of the inner layer circuit board, setting a negative mask, and irradiating with light to cure. ,
(D) After peeling off the carrier film of the photosensitive additive adhesive film irradiated with light,
Heating and drying for 30 minutes, (E) developing with an aqueous alkali solution to form a surface via hole, (F) thermally curing, (G) light and thermally cured photosensitive additive adhesive resin surface. Polishing (H), dissolving the acid-soluble filler exposed on the surface with an acidic aqueous solution, (I) chemically dissolving and roughening the photosensitive additive adhesive resin with an oxidizing agent, (J) plating After applying the catalyst, electroless plating is performed, followed by electrolytic plating, and (K) an etching resist is applied, and a circuit is formed by etching.

Further, the present invention relates to a method for manufacturing a multilayer printed wiring board comprising the following steps. (A) a step of forming an inner layer circuit by etching a double-sided roughened copper clad board obtained by laminating and molding using a copper foil that has been roughened on both sides in advance; After laminating the photosensitive additive adhesive film, a step of setting a negative mask and curing by light irradiation,
(C) After peeling off the carrier film of the photosensitive additive adhesive film irradiated with light,
Heating and drying for 30 minutes, (D) developing with an aqueous alkali solution to form a surface via hole, (E) thermally curing, (F) light and thermally cured photosensitive additive adhesive resin surface. Polishing (G), dissolving the acid-soluble filler exposed on the surface with an acidic aqueous solution, (H) chemically dissolving and roughening the photosensitive additive adhesive resin with an oxidizing agent, (I) plating After applying the catalyst, electroless plating is performed, followed by electrolytic plating, and (J) an etching resist is applied and a circuit is formed by etching.

A characteristic feature of these manufacturing processes is heating after exposure. Heating after exposure with a photosensitive resin composition is conventionally performed using a photoacid generator, in which a chemical bond is cut by an acid to make it solubilized, or a negative resist in which a crosslinking reaction is caused by the acid to make it insoluble. Mold resist and the like. The photosensitive additive adhesive used in the present invention is a negative resist which is insolubilized by radical polymerization, and does not require heat drying after exposure. However, when a dry film is formed on the carrier film, the surface at the time of development (the carrier film side) becomes a surface where a large amount of solvent remains, and if the development is carried out in the state where the solvent is present, the developer resistance of the exposed area is reduced. This causes the via hole shape to deteriorate. Therefore, it is necessary to remove the residual solvent before development. The heating and drying conditions may vary depending on the type of the remaining solvent, but at 60 to 100 ° C.
~ 30 minutes is preferable, and furthermore, 5 ~ 1 at 70 ~ 90 ° C.
It is more preferably 5 minutes, and particularly preferably 80 ° C. and about 10 minutes.

Hereinafter, the present invention will be described in detail with reference to the drawings. First, the surface of the patterned copper foil (2) of the patterned inner layer circuit board (1) is treated with chemicals to roughen it (A, B) as in the prior art. In this case, an inner layer circuit board using a copper foil roughened in advance may be used. Next, the photosensitive additive adhesive film (4)
Is laminated using a vacuum laminator, a normal pressure laminator or the like (C). Subsequently, a negative film is brought into close contact and irradiated with ultraviolet rays. Next, a carrier film of a photosensitive additive adhesive film irradiated with ultraviolet rays (5)
And dried by heating at 60 to 100 ° C. for 5 to 30 minutes. (D) The unexposed portion is dissolved and developed with an aqueous alkaline solution to form a surface photo via hole (6) (E).

Next, the photosensitive additive is heat-treated and thermally cured, and the surface of the cured photosensitive adhesive is mechanically polished. The purpose of this is to expose the acid-soluble filler on the surface at the same time as smoothing the surface. The exposed acid-soluble filler is dissolved by an acidic aqueous solution to form coarse concave portions on the surface. further,
The photosensitive additive adhesive resin is chemically dissolved and roughened by an oxidizing agent to form fine concave portions on the resin surface (F). The oxidizing agent used here is a chromium-sulfuric acid aqueous solution,
An aqueous solution of potassium permanganate may, for example, be mentioned. Next, after applying a catalyst for electroless plating by a known method, chemical copper is plated on the entire surface by electroless plating, and then electrolytic plating is performed to a predetermined thickness by electrolytic plating (G). Thereafter, an etching resist (9) is applied (H), and a circuit (10) is formed by etching (I). After applying the electroless plating catalyst, a permanent plating resist may be applied to the roughened surface of the photosensitive additive adhesive, and surface via holes and circuits may be formed by electroless plating.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. (Synthesis Example 1) Synthesis of methacryloyl group-containing phenol novolak As phenol novolak, phenolite LF-48 was used.
71 (manufactured by Dainippon Ink and Chemicals, Inc.) 800 g (about 4 equivalents of OH) of a 60% non-volatile content of methyl ethyl ketone
, And 0.2 g of hydroquinone and 284 g (2 mol) of glycidyl methacrylate were added.
Warmed to ° C. After 1 g of tributylamine was added thereto, the mixture was stirred and reacted at 110 ° C for 5 hours.

(Synthesis Example 2) Synthesis of epoxy acrylate Bisphenol A type epoxy resin was placed in a 2 l flask.
After adding 760 g (4 equivalents) of Epicoat 828 (made by Yuka Shell Epoxy: epoxy equivalent 190) and 1 g of methoxyphenol as a polymerization inhibitor, 288 g of acrylic acid
(4 moles), 1 g of benzyldimethylamine was added and 10
The reaction was stirred at 0 ° C. for 6 hours.

Example 1 15 g of Epicoat 828,
45 g of the methacryloyl group-containing phenol novolak solution of Synthesis Example 1, 15 g of the epoxy acrylate of Synthesis Example 2 and 15 g of trimethylolpropane triacrylate were mixed, and 3 g of Irgacure 651 (manufactured by Ciba Geigy) as a photoinitiator and a thermosetting accelerator were used. 0.2 g of triphenylphosphine was added, and calcium carbonate was further added to 36 g.
g, and the mixture was thoroughly stirred and defoamed, and then coated and dried with a thickness of 150 μm on a PET carrier film to obtain a photosensitive additive adhesive film.

A glass epoxy double-sided copper-clad laminate having a base material thickness of 0.1 mm and a copper foil thickness of 35 μm was patterned to form an inner circuit board. Then, sodium chlorite 31 g / l,
Sodium hydroxide 15g / l, sodium phosphate 12g
The surface of the circuit was roughened by treating with an aqueous alkaline solution consisting of / l at 95 ° C for 2 minutes, and the photosensitive additive adhesive film prepared above was laminated thereon by a vacuum laminator. Subsequently, a predetermined pattern was placed thereon, and was exposed at an irradiation amount of 200 mJ / cm ² using a high-pressure mercury lamp exposure apparatus, and was heated and dried at 80 ° C. for 10 minutes after the carrier film was peeled off.
Then 2 kg / c with 1% aqueous sodium hydroxide solution
Developed with a spray pressure of m ² to form surface via holes.

The substrate on which the surface via hole is formed is heated at 150 ° C.
The photosensitive additive was thermally cured by heat treatment for 30 minutes, and a hole was formed for a plated through hole. Thereafter, the surface of the photosensitive additive adhesive resin was polished and smoothed with a belt sander, and immersed in a 10% hydrochloric acid aqueous solution to dissolve the calcium carbonate exposed on the surface. continue,
10% alkaline aqueous solution of potassium permanganate at 75 ° C
After roughening for minutes, and washing thoroughly with water, the resultant was immersed in an aqueous solution of hydroxylamine sulfate at 50 ° C. for 10 minutes to neutralize and remove permanganate remaining in the adhesive layer. Next, it was immersed in a 75 ° C. alkali degreasing solution for 5 minutes, washed sufficiently, and immersed in a palladium-tin salt colloid catalyst solution for 5 minutes. After washing with water, it was immersed in a catalyst activation bath at room temperature for 8 minutes to remove excess tin salt from excess palladium-tin salt colloid particles.
Immerse in an electroless copper plating solution at 25 ° C for 1 hour, and
An electroless plating film having a thickness of 25 m was formed, followed by electrolytic plating until the thickness became 25 μm, an etching resist was applied, a circuit was formed by etching, and an additive method multilayer printed wiring board was produced.

<< Example 2 >> 15 g of Epicoat 828,
45 g of a methacryloyl group-containing phenol novolak solution of Synthesis Example 1, 15 g of epoxy acrylate V-5510 (manufactured by Dainippon Ink and Chemicals, Inc.) and 15 g of pentaerythritol triacrylate were mixed, and 3 g of Irgacure 651 as a photoinitiator and accelerated thermal curing. After adding 0.2 g of triphenylphosphine as an agent and 36 g of calcium carbonate, stirring and defoaming well,
The carrier film of T was coated and dried at a thickness of 150 μm to obtain a photosensitive additive adhesive film. Thereafter, an additive method multilayer printed wiring board was manufactured in the same manner as in Example 1.

Example 3 15 g of Epicoat 828
45 g of the methacryloyl group-containing phenol novolak solution of Synthesis Example 1, 15 g of epoxy acrylate SP-4010 (manufactured by Showa Polymer Co., Ltd.), and 15 g of 1,6-hexanediol diacrylate were mixed, and 65 g of Irgacure as a photoinitiator and heat were mixed. After adding 0.2 g of triphenylphosphine as a hardening accelerator and further adding 36 g of calcium carbonate, stirring and defoaming well, a PET carrier film is coated and dried at a thickness of 150 μm, and then exposed to a photosensitive additive. An adhesive film was obtained. In the same manner as in Example 1, an additive method multilayer printed wiring board was manufactured.

Comparative Example 1 The same film as in Example 1 was not heated and dried after exposure. Hereinafter, Example 1
In the same manner as in the above, an additive method multilayer printed wiring board was produced.

Comparative Example 2 The same film as in Example 2 was not heated and dried after exposure. Hereinafter, Example 1
In the same manner as in the above, an additive method multilayer printed wiring board was produced.

Comparative Example 3 The same film as in Example 3 was not heated and dried after exposure. Hereinafter, Example 1
In the same manner as in the above, an additive method multilayer printed wiring board was produced.

Table 1 shows the results of evaluating the characteristics of the additive-processed multilayer printed wiring board obtained in this manner. Table 1 数 Number of curing steps Via hole shape ─────────────────── ────── Example 1 5 Taper Example 2 4 Taper Example 3 6 Taper 比較 Comparative Example 1 3 Undercut Comparative Example 2 2 Undercut Comparative Example 3 3 Undercut ─────────────────────────

(Measurement method) Number of curing steps: A 21-step Stofa step tablet was exposed in close contact, developed for twice the dissolution time of each, and the number of curing steps at which no surface deterioration was observed was observed. Via hole shape: After developing for twice the dissolution time and curing, the via hole cross-sectional shape was observed.

[0032]

As can be seen from the above embodiments, the present invention provides a high-resolution, high-temperature, high-temperature, high-temperature photoreceptor, although the development of photovia holes is easy with an aqueous alkali solution.
It is also excellent in plating solution resistance to electroless plating performed for a long time under high alkalinity conditions, has high adhesive strength with plated copper, and furthermore, it is a multilayer printed wiring board that can withstand temperatures around 260 ° C in the soldering process Manufacturing enabled.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Uesaka 2-5-8 Higashishinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd.

Claims (2)

[Claims] 1. A phenol novolak obtained by condensing (a) a polyfunctional epoxy resin having an epoxy equivalent of 120 to 500 and (b) bisphenol A or F with formaldehyde in the presence of an acidic catalyst.
Modified bisphenol novolak obtained by reacting about 60% with glycidyl acrylate or glycidyl methacrylate, (c) an epoxy acrylate or epoxy methacrylate compound, (d) a diluent composed of a polyfunctional photopolymerizable monomer, (e) a photopolymerization initiator, F) A multilayer printed wiring board using a photosensitive additive adhesive film obtained by applying a photosensitive additive adhesive resin composition comprising an acid-soluble filler to a carrier film, comprising the following steps (A) to (K). A method for producing a multilayer printed wiring board, which is characterized by the following. (A) Etching the double-sided copper clad board,
Forming an inner layer circuit, (B) roughening the inner layer circuit surface, (C) laminating the photosensitive additive adhesive film on both or one side of the inner layer circuit board,
Setting a negative mask and irradiating with light, curing (D) removing the carrier film of the photosensitive additive adhesive film irradiated with light, and heating and drying at 60 to 100 ° C. for 5 to 30 minutes; (E) alkali Developing with an aqueous solution to form a surface via hole, (F) thermally curing, (G) smoothing and polishing the light and thermally cured photosensitive additive adhesive resin surface, (H) exposing to the surface Dissolving the obtained acid-soluble filler with an aqueous acidic solution, (I) chemically dissolving and roughening the photosensitive additive adhesive resin with an oxidizing agent, (J) applying a plating catalyst, and then subjecting the electroless plating to electroless plating. Performing, followed by electrolytic plating, and (K) a step of applying an etching resist and forming a circuit by etching. 2. A multilayer printed wiring board using the photosensitive additive adhesive film according to the above (a) to (f), wherein the multilayer printed wiring board has the following steps (A) to (J): Manufacturing method. (A) a step of etching a double-sided roughened copper-clad board obtained by laminating and molding using a copper foil that has been roughened on both sides in advance to form an inner layer circuit;
(B) a step of laminating the photosensitive additive adhesive film on both surfaces or one surface of the inner circuit board, setting a negative mask and irradiating with light, and (C) a step of curing the photosensitive additive adhesive film irradiated with light. After the carrier film is peeled off, a step of heating and drying at 60 to 100 ° C. for 5 to 30 minutes, (D) a step of developing with an aqueous alkali solution to form a surface via hole, and (E) a thermosetting step.
(F) a step of smoothing and polishing the light- and heat-cured photosensitive additive adhesive resin surface, and (G) a step of dissolving the acid-soluble filler exposed on the surface with an acidic aqueous solution,
(H) a step of chemically dissolving and roughening the photosensitive additive adhesive resin with an oxidizing agent, (I) a step of performing electroless plating after applying a plating catalyst, and subsequently performing electrolytic plating, (J). A step of applying an etching resist and forming a circuit by etching.