JP2009295872A - Method for manufacturing printed circuit board, and printed circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a printed circuit board which has excellent fine wiring formation property and insulation reliability. <P>SOLUTION: The method for manufacturing the printed circuit board at least includes processes of: (A) forming a groove 4 by irradiating a part where nonelectrolytic plating 2 of an insulating resin material 1 is to be deposited with a laser beam, using the insulating resin material 1 in which nonelectrolytic plating is not deposited at least before the laser beam is irradiated and the nonelectrolytic plating 2 is deposited only at a part where the laser beam is irradiated; and (B) forming the nonelectrolytic plating 2 in the groove 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printed wiring board manufacturing method and a printed wiring board.

  2. Description of the Related Art In recent years, electronic devices have been rapidly improved in performance, function, and size, and accordingly, there is an increasing demand for downsizing and weight reduction of electronic components used in electronic devices. In response to the above requirements, semiconductor device packaging methods and wiring boards on which they are mounted are required to have higher density, higher functionality, and higher performance.

  By the way, as a method of obtaining such a wiring board (printed wiring board), a full additive printed wiring board can be mentioned.

  As a conventional method for producing a full additive printed wiring board, an adhesive layer containing an electroless plating catalyst is applied and formed on a glass epoxy substrate containing an electroless plating catalyst to obtain a laminate. Next, through holes are selectively formed in the laminate. Next, desmear removal is performed, after which an electroless copper plating catalyst is applied in the through hole, and a permanent resist layer is applied and formed by a screen printing method. Next, there is a method in which the permanent resist is patterned by a method such as exposure and development, and further electroless plating is performed to obtain a wiring at a desired location (see, for example, Patent Document 1). A method of forming a thick wiring layer only by electroless plating is called a full additive method, and is distinguished from a subtractive method and a semi-additive method.

However, in the above manufacturing method, because the electroless plating catalyst that retains the activity is contained in the entire surface of the insulating resin, the wiring is caused by abnormal deposition at the location where the electroless plating catalyst exists, particularly in the case of fine wiring. There is a problem in that they are electrically connected to each other and the insulation reliability is lowered.
Japanese Patent Laid-Open No. 11-40923

  This invention is made | formed in view of said subject, The objective is to provide the manufacturing method of a printed wiring board with high insulation reliability, and a printed wiring board.

  As a result of intensive studies in view of the above-mentioned problems, the present inventors are an insulating resin material in which electroless plating does not deposit before laser irradiation, and the electroless plating is deposited only in the laser irradiated portion. It has been found that the above problems can be solved by a method for producing a printed wiring board using an insulating resin material, and the present invention has been completed.

  That is, the present invention is an insulating resin material in which electroless plating does not deposit at least before laser irradiation, and at least using an insulating resin material in which electroless plating is deposited only at a position irradiated with laser, A) A step of forming a groove by irradiating a laser at a portion where the electroless plating of the insulating resin material is deposited, and B) a step of forming an electroless plating in the groove. It relates to a manufacturing method.

  Further, in the method of manufacturing the printed wiring board, when the electroless plating treatment is performed on the insulating resin material in which the groove is formed in the step B), the insulating resin material from which the electroless plating other than the groove is not exposed is exposed. The electroless plating is not deposited on the portion that is being formed, and the electroless plating is deposited on the groove portion.

Furthermore, it is preferable that the manufacturing method of the said printed wiring board includes a C) desmear process.
In that case, it is preferable to process in the order of A), C) and B).

  Furthermore, it is preferable to include a step of forming D) a through hole. In that case, processing is performed in the order of A), D), C), and B), or processing is performed in the order of D), A), C), and B). It is preferable.

  Moreover, this invention relates to the printed wiring board obtained by the manufacturing method of the said printed wiring board.

  By the method for manufacturing a printed wiring board according to the present invention, a printed wiring board having excellent fine wiring formability and insulation reliability can be manufactured.

  Embodiments of the present invention will be described below.

(Configuration and form of insulating resin material)
The insulating resin material used in the present invention is an insulating resin material that does not deposit electroless plating at least before being irradiated with laser, and is characterized in that electroless plating is deposited only at a portion irradiated with laser. Therefore, the insulating resin material itself is an insulating resin material that does not deposit electroless plating. The form of the insulating resin material according to the present invention is not particularly limited, and examples thereof include lumps, films, solutions, and the like. Therefore, for example, when the insulating resin material used in the present invention is in the form of a film, it has a configuration and form of a single layer film of an insulating resin material in which electroless plating does not deposit.

  Here, the insulating resin material on which electroless plating is not deposited will be described.

  In the present invention, electroless plating does not deposit means that when electroless plating is deposited to a thickness of a μm at a location where electroless plating is deposited, a thickness of a × (1/7) μm or less is deposited. Is defined. For example, when the electroless plating is deposited by a thickness of 7 μm at a location where the electroless plating is deposited, the electroless plating is deposited by a thickness of 1 μm or less on the insulating resin material where the electroless plating is not deposited. Here, the electroless plating layer deposited by a thickness of a × (1/7) μm or less can be removed by a known method such as soft etching with an acidic aqueous solution. Therefore, in the end, the electroless plating is not substantially formed on the insulating resin material on which the electroless plating does not deposit, and the electrical insulation can be maintained. Of course, when the electroless plating is not substantially deposited on the insulating resin material on which the electroless plating is not deposited, it is not necessary to perform soft etching or the like.

  Here, when the electroless plating layer is removed by a method such as soft etching, the electroless plating layer where the electroless plating layer is deposited is also removed. Therefore, if a thickness of a × (1/7) μm or more is formed on an insulating resin material on which electroless plating does not deposit, the shape of the resulting wiring may be abnormal, or the wiring thickness may vary from the design. Problems arise.

  The insulating resin material on which the electroless plating according to the present invention is not deposited may be an insulating resin material on which the electroless plating is not deposited because the electroless plating catalyst is not imparted, and the electroless plating catalyst is imparted, An insulating resin material that does not deposit electroless plating because it does not exhibit catalytic activity may be used, and an electroless plating catalyst is provided. However, since the catalytic activity is low, the electroless plating is a μm at the location where electrolytic plating is deposited. May be an insulating resin material that deposits by a thickness of a × (1/7) μm or less.

  In order to prevent the electroless plating catalyst from being applied, the electroless plating catalyst and the surface of the insulating resin material on which the electroless plating is not deposited may be in a state where they do not interact with each other. For example, if the electroless plating catalyst has a feature that it interacts with and adsorbs amino groups, it prevents the application of the electroless plating catalyst by preventing the amino groups from being introduced into the surface of the insulating resin material. Can do.

  Moreover, it is preferable if the catalyst concentration on the surface of the insulating resin material on which electroless plating is not deposited is 0.2% or less in terms of the atomic concentration calculated by XPS analysis, because electroless plating tends not to be deposited. When the catalyst concentration is higher than 0.2%, the electroless plating is likely to be deposited.

  Although the above electroless plating catalyst is provided, in order not to show catalytic activity, a compound showing a catalyst poison with respect to the electroless plating catalyst is added to the insulating resin material where electroless plating does not deposit. It can be exposed to the surface. For example, when the electroless plating catalyst loses catalytic activity due to interaction with the phosphorus compound, the catalytic activity of the electroless plating catalyst can be deactivated by a method of adding a phosphorus compound to the resin layer.

  In addition, for example, when using an electroless plating catalyst, particularly a palladium catalyst generally used as an electroless copper plating catalyst, palladium is poisoned by a compound having sulfur and a compound having chromium. The catalytic activity of the electroless plating catalyst can be deactivated by the method of adding the catalyst.

  The inventors have also discovered that palladium is poisoned by compounds having an oxime structure. This is considered because the compound having an oxime structure and palladium form a complex. Examples of the compound having an oxime structure include 1,2-octanedione-, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2- Methylbenzoyl) -9H-carbazol-3-yl]-, 1- (0-acetyloxime), and the like. For the compound having an oxime structure, the catalytic activity of the electroless plating catalyst can be deactivated by the same method as described above.

  Next, the insulating resin material of the present invention is characterized in that electroless plating is deposited only at least at a location irradiated with a laser. This point will be described.

  By irradiating the insulating resin material of the present invention with a laser, the resin is removed only at the place where the laser irradiation has been performed, and a groove is formed. At this time, the surface of the grooved portion may be formed by electroless plating by utilizing either chemical modification by laser irradiation, physical modification, or both.

  The chemical modification will be described. As described above, in order to deposit electroless plating, an electroless plating catalyst needs to be applied. The inventors have estimated the following two mechanisms as chemical modification by laser irradiation.

  One is thermal decomposition of the resin and the added compound by laser irradiation. For example, when a compound that inactivates an electroless plating catalyst is added to an insulating resin material that does not deposit electroless plating, the above-mentioned compound is thermally decomposed by laser irradiation to inactivate the catalyst. By deactivating, it is considered that an electroless plating catalyst is provided and electroless plating is deposited.

  The other is generation of functional groups by laser irradiation. For example, by irradiating an insulating resin material that does not deposit electroless plating with a laser, a specific functional group is generated only at the irradiated location, and this functional group interacts with the electroless plating catalyst to give a catalyst. It is thought that electroless plating starts to deposit.

  Next, physical modification will be described. The inventors have estimated the following mechanism as a physical modification by laser irradiation. That is, surface irregularities are formed at the laser irradiation location. It is considered that the electroless plating catalyst is physically imparted in the unevenness by forming the surface unevenness, and the electroless plating is deposited.

  As described above, in the insulating resin material of the present invention, the point that the electroless plating is deposited only at least at the place irradiated with the laser has been described, but such conditions are satisfied and the insulating property and heat resistance of the obtained printed wiring board are obtained. In view of this aspect, the insulating resin material according to the present invention preferably contains an epoxy resin and / or a polyimide resin. Moreover, it is especially preferable to contain an epoxy resin and / or a thermoplastic polyimide resin from an adhesive viewpoint with the electroless plating of the location irradiated with the laser.

  In addition, a thermoplastic resin, a thermosetting resin, a filler, a flame retardant, and the like may be appropriately added to the insulating resin material of the present invention for the purpose of improving mechanical properties and imparting flame retardancy.

  The thickness of the insulating resin material of the present invention is not particularly limited, but is preferably 1 nm or more. If the thickness is less than 1 nm, it is difficult to produce a printed wiring board using the insulating resin material.

(Laminated)
In the manufacturing method of the printed wiring board of this invention, you may include the process of laminating | stacking an insulating resin material on a base material. The method of lamination depends on the form of the material used, and when the insulating resin material is in the form of a film, it may be performed by hot pressing, laminating (thermal laminating), hot roll laminating, etc., and is particularly limited. is not. When the insulating resin material is a solution, the insulating resin layer can be formed by a known method such as a comma coater, a bar coater, or a spin coater. In addition, the base material in this invention refers to various film materials, such as PET film and a polyimide film, various substrates, such as a glass epoxy board | substrate and a ceramic board | substrate, etc., The wiring may be formed in these materials.

(Process to form by irradiating with laser)
The method for producing a printed wiring board of the present invention is an insulating resin material in which electroless plating is not deposited at least before being irradiated with a laser, and the electroless plating is deposited only in a portion irradiated with the laser. And at least A) a step of forming a groove by irradiating a laser to a portion where the electroless plating of the insulating resin material is deposited. In the present invention, it is essential to form the groove so as not to penetrate the insulating resin material.

  As the laser used in the present invention, a commonly used laser device may be used, and examples thereof include a carbon dioxide gas laser, a UV laser, a YAG laser, and an excimer laser. Further, the groove may be formed by adjusting the laser type and the laser conditions depending on the insulating resin material to be used.

  The groove formed in the present invention is preferably 100 μm or less in width and 100 μm or less in thickness from the viewpoint of forming fine wiring, and preferably 50 μm or less in width and 50 μm or less in thickness.

  Further, when forming the groove, a blind via hole or a through hole may be formed together.

(Through hole formation)
The method for manufacturing a printed wiring board of the present invention may include a step of forming a through hole. The through hole can be formed using a known method such as a mechanical drill, laser, punching or the like.

(Desmear)
The method for producing a printed wiring board of the present invention may incorporate a desmear process before electroless copper plating for the purpose of removing smear generated at the time of forming a through hole or at a location where a groove is formed. As the desmear, any method such as wet desmear or dry desmear may be used.

  In the case of wet desmear, it is possible to use a commercially available desmear chemical solution and process, but generally it consists of three steps of swelling, roughening, and neutralization. An alkaline aqueous solution of potassium acid or sodium permanganate is used.

  In the case of dry desmear, the case of using plasma, the case of using corona, etc. can be exemplified. In either case, both normal pressure and reduced pressure can be performed.

(Electroless plating)
The manufacturing method of the printed wiring board of this invention includes the process of electroless-plating.
There are no particular limitations on the electroless plating used in the present invention, direct plating using carbon, palladium catalyst, organic manganese conductive film, etc., electroless copper plating, electroless nickel plating, electroless gold plating, electroless silver plating , Electroless tin plating and the like, and can be used in the present invention.

  Among these, electroless copper plating and electroless nickel plating are preferable from the viewpoint of electrical characteristics such as productivity and migration resistance, and among electroless plating, electroless copper plating is particularly preferable. Hereinafter, electroless copper plating will be described.

  As a method of depositing electroless copper plating on the resin layer on which electroless plating of the present invention is deposited, after electroless copper plating catalyst such as palladium catalyst is applied, electroless copper plating is applied. A method of depositing electroless copper plating with a plating catalyst as a core, etc. can be mentioned, but from the viewpoint of depositing electroless copper plating uniformly, after applying an electroless copper plating catalyst such as a palladium catalyst, A method of depositing electroless copper plating using palladium as a nucleus is preferred.

  The thickness of the electroless plating is not particularly limited and may be deposited up to a desired conductor layer thickness. However, from the viewpoint of forming fine wiring, the electroless plating thickness is preferably in the range of 1 μm to 30 μm.

  Moreover, after forming electroless plating with a thickness of about 5 μm or less, it may be deposited up to a desired conductor layer thickness by electrolytic plating.

(Printed wiring board manufacturing method)
The present invention is an insulating resin material in which electroless plating is not deposited at least before laser irradiation, and at least A) using an insulating resin material in which electroless plating is deposited only at a position irradiated with laser. A step of forming a groove by irradiating a laser at a portion where the electroless plating of the insulating resin material is deposited, and B) a step of forming an electroless plating in the groove. In addition, in the step B), when the insulating resin material in which the groove is formed is subjected to the electroless plating treatment, the portion where the insulating resin material other than the groove where the electroless plating is not deposited is exposed is electroless. Plating is not deposited, and electroless plating is deposited in the groove portion.

  Therefore, according to the method for manufacturing a printed wiring board of the present invention, since electroless plating is deposited not only from the bottom of the groove formed by laser irradiation but also from the side of the groove, the adhesion between the electroless plating and the insulating resin material High nature. Further, since the electroless plating is uniformly deposited from the bottom and side surfaces of the groove, the wiring shape can be easily controlled as designed.

  Further, since the groove can be formed only at a desired location, the fine wiring formability is excellent.

  Furthermore, since electroless plating is deposited only at the locations irradiated with laser, there is an advantage that the insulation reliability between wirings is excellent.

  It is preferable that the manufacturing method of the said printed wiring board includes a C) desmear process from a viewpoint of removing the residue of the insulating resin of the location irradiated with the laser. For these reasons, it is preferable to process in the order of A), C), and B).

  Furthermore, when manufacturing a double-sided printed wiring board, it is preferable to include the step of D) forming a through hole in order to allow conduction on both sides. In that case, it is preferable to include a C) desmear process for the purpose of removing the residue in the through hole. For this reason, A), D), C), B) are processed in this order, or D), A ), C) and B) are preferably processed in this order.

(Printed wiring board)
The printed wiring board of the present invention is obtained by the above production method. The schematic diagram of the printed wiring board obtained by the manufacturing method of this invention is shown in FIG. The insulating resin material 1 is located on the base material 3. A plating 2 is formed in the groove 4 of the insulating resin material.

  The printed wiring board produced by the method for producing a printed wiring board of the present invention has an advantage that the electroless plating and the insulating resin material have high adhesion, and the wiring shape can be easily controlled as designed.

  Further, since the groove can be formed only at a desired location, the fine wiring formability is excellent.

  Furthermore, since electroless plating is deposited only at the locations irradiated with laser, there is an advantage that the insulation reliability between wirings is excellent.

  As mentioned above, although the manufacturing method of the printed wiring board of this invention and the printed wiring board were demonstrated, it cannot be overemphasized that the manufacturing method of a printed wiring board of this invention and a printed wiring board are not limited to this. Nor.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to these. In addition, the fine wiring formability in an Example and a comparative example was evaluated as follows.

[Fine wiring formability]
About the printed wiring board obtained by the Example and the comparative example, the case where conduction | electrical_connection was not confirmed by the wiring formation location of wiring width / wiring space | interval = 10micrometer / 10micrometer was made into pass, and the case where conduction was confirmed was made disqualified.

(Synthesis Example 1: Synthesis of thermoplastic polyimide)
In a glass flask with a volume of 2000 ml, 37 g (0.045 mol) of amino acid-modified silicone oil (KF-8010 manufactured by Shin-Etsu Chemical Co., Ltd.), 21 g (0.105 mol) of 4,4′-diaminodiphenyl ether, and DMF And dissolved with stirring, 78 g (0.15 mol) of 4,4 ′-(4,4′-isopropylidenediphenoxy) bis (phthalic anhydride) was added, and the mixture was stirred at 20 ° C. for about 1 hour. A polyamic acid solution having a solid content concentration of 30% was obtained. The polyamic acid solution was placed on a fluorine-coated vat and heated under reduced pressure at 200 ° C. for 120 minutes at 665 Pa in a vacuum oven to obtain polyimide resin 1.

(Preparation Example 1; Preparation 1 of insulating resin material solution)
20 parts by weight of the polyimide resin 1 obtained in Synthesis Example 1 and 2-octanedione-, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], which is a compound having an oxime structure (Ciba 10 parts by weight of Specialty Chemicals Co., Ltd. Irgacure OXE 01) was added to 70 parts by weight of 1,3-dioxolane, and stirred and dissolved to obtain an insulating resin material solution (a).

(Formulation Example 2; Preparation 2 of insulating resin material solution)
20 parts by weight of the polyimide resin 1 obtained in Synthesis Example 1 and 1,2-octanedione-, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], which is a compound having an oxime structure ( 10 parts by weight of Ciba Specialty Chemicals Co., Ltd. Irgacure OXE 02) was added to 70 parts by weight of 1,3-dioxolane, uniformly stirred and dissolved to obtain an insulating resin material solution (b).

(Example 1)
An insulating resin material solution (a) was applied on a support (trade name: Lumirror T-60, manufactured by Toray Film Processing Co., Ltd .; 38 μm) so that the final thickness of the insulating resin material was 20 μm, and at 60 ° C. for 5 minutes. Heating was performed to obtain a laminate of insulating resin material (A) / support. The laminated resin resin material (A) and a glass epoxy board (product number: CS-3665D, manufactured by Risho Kogyo Co., Ltd .; copper thickness: 5 μm) with double-sided copper foil are opposed to each other, at the first stage, at a temperature of 90 ° C. After vacuum lamination under the conditions of vacuum drawing 30 seconds, release to the atmosphere, pressurization time 30 seconds, and the second stage, temperature 110 ° C., pressure 1 MPa, pressurization time 60 seconds, the support is peeled off, A laminate of glass epoxy substrate / insulating resin material (A) was obtained.

  The laminate was processed from the insulating resin material (A) side with a UV laser so that the line / space was 10 μm / 10 μm and the thickness was 5 μm.

  After forming a through hole in the laminate obtained in this way with a mechanical drill, it was subjected to a desmear treatment with a reduced-pressure plasma treatment, followed by a palladium catalyst and electroless copper plating (Rohm and Haas Co., Ltd.) By applying the CUPOSIT thickening type), a copper wiring having a line / space of 10 μm / 10 μm and a thickness of 5 μm was formed to obtain a printed wiring board. The results of evaluating the fine wiring formability of this printed wiring board are shown in Table 1.

(Example 2)
The insulating resin material solution (b) was applied on a support (trade name: Lumirror T-60, manufactured by Toray Film Processing Co., Ltd .; 38 μm) so that the final thickness of the insulating resin material was 20 μm, and at 60 ° C. for 5 minutes. Heating was performed to obtain a laminate of insulating resin material (B) / support. The laminated resin resin material (B) and a glass epoxy substrate (product number: CS-3665D, manufactured by Risho Kogyo Co., Ltd .; copper thickness: 5 μm) with double-sided copper foils are opposed to each other, at the first stage, at a temperature of 90 ° C. After vacuum lamination under the conditions of vacuum drawing 30 seconds, release to the atmosphere, pressurization time 30 seconds, and the second stage, temperature 110 ° C., pressure 1 MPa, pressurization time 60 seconds, the support is peeled off, A laminate of glass epoxy substrate / insulating resin material (B) was obtained.

  The laminate was processed from the insulating resin material (B) side with a UV laser so that the line / space was 10 μm / 10 μm and the thickness was 5 μm.

  After forming a through hole in the laminate obtained in this way with a mechanical drill, it was subjected to a desmear treatment with a reduced-pressure plasma treatment, followed by a palladium catalyst and electroless copper plating (Rohm and Haas Co., Ltd.) By applying the CUPOSIT thickening type), a copper wiring having a line / space of 10 μm / 10 μm and a thickness of 5 μm was formed to obtain a printed wiring board. The results of evaluating the fine wiring formability of this printed wiring board are shown in Table 1.

(Comparative Example 1)
On one side of a glass epoxy substrate (E) (trade name: ACL3-E-168, 1.44t, manufactured by Hitachi Chemical Co., Ltd.) containing an electroless copper plating catalyst, a photosensitive permanent resist layer (F) (Hitachi Chemical Industry Co., Ltd.) Product name: negative photosensitive film FOTECH SR-3000) was laminated at a temperature of 110 ° C. at a rate of 2 m / min to obtain a laminate. A mask pattern having a wiring width / wiring interval = 10 μm / 10 μm was placed on the photosensitive permanent resist layer of the laminate, and light having a wavelength of 365 nm was exposed by 300 mJ / cm ² . Subsequently, using a spray developing machine (etching machine ES-655D manufactured by Sunhayato Co., Ltd.), with a developer (diethylene glycol, monobutyl ether: 200 ml / L, water: 800 ml / L, borax: 8 / L), A spray development treatment was performed at a liquid temperature of 40 ° C. to partially expose a glass epoxy substrate containing an electroless copper plating catalyst. After forming a through hole in the laminate obtained in this way with a mechanical drill, subsequently, electroless copper plating (CUPOSIT thickening type manufactured by Rohm and Haas) is applied to form a wiring having a thickness of 10 μm. The printed wiring board was obtained. The results of evaluating the fine wiring formability of this printed wiring board are shown in Table 1.

  As shown in the comparative example, the electroless copper plating catalyst is present in unnecessary places (the entire surface of the glass epoxy substrate), so the electroless copper plating is applied to the interface between the permanent resist layer and the glass epoxy substrate during electroless copper plating. As a result, abnormal precipitation occurs, resulting in electrical conduction at the fine wiring locations.

  On the other hand, in the examples, since there is no interface between the materials as seen in the comparative example, no abnormal deposition of electroless copper plating was observed, and good insulation reliability was exhibited even at fine wiring locations.

Schematic diagram of a printed wiring board obtained by the production method of the present invention

Explanation of symbols

1 Insulating resin material 2 Plating 3 Base material 4 Groove

Claims (8)

  At least using an insulating resin material that is an insulating resin material in which electroless plating does not deposit before being irradiated with a laser, and in which only the portion irradiated with the laser is deposited. A) The insulating resin material A method for producing a printed wiring board, comprising: forming a groove by irradiating a laser at a location where the electroless plating is deposited; and B) forming an electroless plating in the groove.   In the step B), when an electroless plating process is performed on the insulating resin material in which the groove is formed, the electroless plating is exposed to a portion where the insulating resin material other than the groove where the electroless plating is not deposited is exposed. 2. The method of manufacturing a printed wiring board according to claim 1, wherein electroless plating is deposited in the groove portion without being deposited.   The method for producing a printed wiring board according to claim 1, further comprising a C) desmear process.   The method for manufacturing a printed wiring board according to claim 3, wherein the processing is performed in the order of A), C), and B).   5. The method for producing a printed wiring board according to claim 1, further comprising D) a step of forming a through hole.   The method for manufacturing a printed wiring board according to claim 5, wherein the processing is performed in the order of A), D), C), and B).   6. The printed wiring board manufacturing method according to claim 5, wherein the processing is performed in the order of D), A), C), and B).   A printed wiring board obtained by the manufacturing method according to claim 1.