JP2006202793A - Process for producing printed board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an environment-friendly process for producing a printed board having no etching step in which high definition and high reproducibility are ensured without producing a waste developer. <P>SOLUTION: In the process for producing a printed board by a printing method, a lithographic printing original plate exhibiting affinity to ink variable through irradiation with energy is employed. The process for producing a printed board comprises steps of: (1) forming a lithographic printing original plate by irradiating a lithographic printing original plate, exhibiting affinity to ink variable through irradiation with energy, with energy according to a circuit pattern; (2) installing a lithographic printing plate thus obtained on a lithographic offset press; (3) supplying conductive paste and wetting water onto the printing plate and sticking the conductive paste according to the circuit pattern; and (4) transferring the circuit pattern-like conductive pattern to a board through a rubber blanket. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printed circuit board manufacturing method, and more particularly to a printed circuit board manufacturing method by a printing method using a lithographic printing original plate.

  Printed circuit boards are used in various electronic devices such as word processors, personal computers, copying machines, and facsimiles. In general, a printed circuit board is manufactured by applying a resist to a copper foil bonded to a substrate, exposing, developing, and etching to form a conductive circuit (circuit pattern), a so-called subtractive method. Yes. In the case of forming a fine conductive circuit, a so-called additive method is employed in which a desired conductive circuit is formed by electroless plating or electrolytic plating using a plating resist.

  However, since the former manufacturing method requires a step of removing most of the areas other than the circuit pattern by etching, there is a problem of cost increase of materials or environmental pollution due to waste liquid. Further, in the latter manufacturing method, the deposition rate of electroless plating is slow, and the thickness of the electrolytic plating tends to be uneven, so that production efficiency and yield also become problems. Therefore, there is a demand for a novel printed circuit board manufacturing method in which a conductive circuit, particularly a fine conductive circuit having a width of 100 μm or less, is patterned only at a predetermined portion with high productivity.

  In Patent Document 1 (Japanese Patent No. 2616526), a paste in which copper powder is dispersed in a phenol resin and / or a polyimide resin is prepared, and the paste is printed on a substrate by a screen printing method, and then heated and cured. Thus, a printed circuit board manufacturing method for forming a conductive circuit is disclosed. In the manufacturing method of the above patent, unlike the conventional subtractive method, there is no fear of waste liquid contamination caused by the etching process, and moreover, only the necessary amount of copper powder is used, so the cost can be reduced. ing. However, in the screen printing method, relatively good pattern printing is possible with a conductive circuit having a line width of 100 μm or more, but it is difficult to accurately form a conductive circuit with a line width of 100 μm or less, particularly about 25 to 50 μm. is there. That is, with such a line width, there is a problem that it is impossible to meet the recent demands for reducing the size and thickness of various electric devices.

  In Patent Document 2 (Japanese Patent Laid-Open No. 11-191669), a conductive circuit base formed by pattern printing on an insulating substrate by an intaglio offset printing method using a conductive paste containing metal powder and resin, and conductive A printed circuit board comprising a copper coating layer formed by electrolytic copper plating on a circuit base is disclosed. The above publication discloses that a printed circuit board having a line width of 30 μm and a line spacing of 25 μm can be produced by the intaglio offset printing method. If a printed circuit board is manufactured using this intaglio offset printing method, a conductive circuit having a line width of 100 μm or less can be accurately formed without the etching process performed by the subtractive method. However, when an intaglio printing plate is prepared, an etching process is required, and there remains a problem that costs and development waste liquid are generated and an environmental load is applied.

On the other hand, for the lithographic printing plate, a method of creating a plate by scanning directly on a printing original plate by scanning a laser, a so-called CTP (Computer To Plate) method has been put to practical use. In particular, in the thermal type CTP plate, post-processing such as development and etching can be omitted, and it is expected that a so-called development-less plate can be obtained.
Japanese Patent No. 2616526 JP-A-11-191669

  An object of the present invention is to provide a method for producing a printed circuit board by a printing method, and particularly to provide an environment-friendly printed circuit board production method in which an etching process is not performed during the production process, high definition, high reproducibility, and no development waste liquid. It is.

  As a result of studying a method for producing a printed circuit board by a printing method, the present inventors have found that a plate having a development process may cause variations in the area of the image area if the development conditions are poorly controlled. In the plate, the image area (ink-adhered area) is formed only by laser exposure, so the high reproducibility of the laser can be used as it is. Accordingly, as a result of intensive studies, the present inventors have manufactured a printed circuit board by a printing method using a lithographic printing plate having the property of changing the affinity for ink by energy irradiation, thereby achieving high-definition and high-reproducibility printing. The inventors have found that a substrate can be produced in a large amount at a low cost, in a high productivity, and in an environment-friendly manner without developing waste liquid, and the present invention has been completed.

That is, the present invention has the following configuration.
(1) A method for producing a printed circuit board having a conductive circuit formed on an insulating substrate by a printing method, wherein a lithographic printing plate having a property that the affinity for ink is changed by energy irradiation is used. .
(2) The method of manufacturing a printed circuit board is as follows: 1) A process for producing a lithographic printing plate by irradiating energy according to a circuit pattern onto a lithographic printing plate having the property that the affinity for ink changes when irradiated with energy; ) The process of installing the obtained lithographic printing plate on a lithographic offset printing machine, 3) The process of supplying the conductive paste and fountain solution onto the printing plate and attaching the conductive paste to the circuit pattern, 4) This The printed circuit board manufacturing method according to (1), comprising a step of transferring the circuit pattern-like conductive pattern to the substrate through a blanket.
(3) The printed circuit board manufacturing method according to (1) or (2), wherein the energy for changing the affinity for ink is light.
(4) The printed circuit board manufacturing method according to (3), wherein the irradiated light is infrared laser light.
(5) The method for producing a printed circuit board according to (1) or (2), wherein the energy for changing the affinity for the ink is heat.
(6) The printed circuit board according to any one of (1) to (5), wherein the lithographic printing original plate is a lithographic printing original plate made of a hydrophilic resin having a cross-linked outermost layer and having a property of reducing hydrophilicity upon energy irradiation. Production method.
(7) The cross-linked hydrophilic resin layer of the outermost surface layer is mainly composed of one or more monomers selected from unsubstituted or substituted (meth) acrylamide, N-vinylformamide, and N-vinylacetamide. The method for producing a printed circuit board according to (6), which is obtained by crosslinking a polymerized hydrophilic polymer.
(8) The cross-linked hydrophilic resin layer of the outermost surface layer comprises an oleophilic polymer having an average particle diameter of 0.005 to 0.5 μm and a minimum film forming temperature of 50 ° C. or less (6) And the printed circuit board manufacturing method as described in (7).
(9) The printed circuit board manufacturing method according to any one of (6) to (8), comprising a photothermal conversion material that converts light into heat in the crosslinked hydrophilic resin layer of the outermost surface layer.
(10) The printed circuit board manufacturing method according to (9), wherein the photothermal conversion material is an infrared absorbing dye having an absorption maximum at 700 to 1100 nm.

  By using the printed circuit board manufacturing method of the present invention, it is possible to manufacture a high-definition and highly reproducible printed circuit board in a large amount at a low cost by an environment-friendly method without developing waste liquid.

Hereinafter, the printed circuit board manufacturing method of the present invention will be described in detail.
[Lithographic printing plate]
The present invention is characterized in that a lithographic printing plate having a property that the affinity for ink changes by energy irradiation is used. Preferably, what is referred to as “development-less” which does not require a post-process such as development after energy irradiation is the outermost surface where the affinity for ink changes by energy irradiation. The energy source to be irradiated is not particularly limited as long as the affinity for ink changes sufficiently between the irradiated site and the non-irradiated site, and may be light or heat. Also, the affinity for the ink may be higher or lower at the irradiated site than at the non-irradiated site. For example, a development-less lithographic printing plate having a hydrophilic resin layer that changes from hydrophilic to oleophilic on heat on the outermost surface is one of the preferred embodiments of the present invention. The development-less lithographic printing plate precursor having such a hydrophilic resin layer on the outermost surface is exemplified by what can be obtained by crosslinking a hydrophilic resin composition placed directly on a support or through an underlayer. be able to.

[Support]
There is no restriction | limiting in particular as a support body of the lithographic printing original plate used for this invention, A well-known thing can be used. Specific examples include metal plates such as aluminum plates, steel plates, stainless steel plates and copper plates, plastic films and papers such as polyester, nylon, polyethylene, polypropylene, polycarbonate, ABS resin, and plastic film laminated paper. The thickness of these supports is not particularly limited, but is usually about 100 to 400 μm. Further, these supports may be subjected to surface treatment such as oxidation treatment, chromate treatment, sand blast treatment, corona discharge treatment, etc. in order to improve adhesion to the underlayer.

[Underlayer]
In the lithographic printing original plate used in the present invention, a hydrophilic resin layer may be directly provided on the support, but it is also a preferable aspect to provide a base layer in order to improve adhesion. The composition of the base layer used at this time is not particularly limited, but it is preferable to use the same type of resin as the lipophilic polymer contained in the hydrophilic resin layer. It is particularly preferable to use a lipophilic polymer such as urethane, acrylic, vinyl acetate, synthetic rubber, or ethylene.

  The lipophilic polymer used for these underlayers may be an aqueous solution or a homogeneous solution dissolved in an organic solvent, or may be in the form of an emulsion, and these can be formed into a base layer. An aqueous emulsion type is particularly preferred because harmful volatile organic solvents are not discharged during film formation. This lipophilic polymer emulsion may be a forced emulsification type or a self-emulsification type.

  This emulsion preferably has a property of forming a film by fusion when the dispersion solvent evaporates after coating. If there is no problem in manufacturing, the minimum film forming temperature is not particularly limited. One kind or two or more kinds of the lipophilic polymers can be mixed and used for the underlayer. Furthermore, a tough film can be formed by adding a crosslinking agent.

[Hydrophilic resin layer]
Next, the hydrophilic resin layer that can be used for the lithographic printing original plate used in the present invention will be described. The lithographic printing original plate used in the present invention is preferably a development-less plate for lithographic offset printing using a fountain solution, and the heated portion of the hydrophilic resin layer is changed to oleophilic to form an image portion. preferable. The plate on which the image line portion is formed can be directly installed in a printing machine without any post-process such as development, and ink can be attached only to the image line portion by supplying dampening water and ink. Therefore, in the present invention, it is preferable that the hydrophilic resin layer is hydrophilic and does not dissolve in water, while the heated portion is oleophilic. In order to embody a hydrophilic resin layer having such characteristics, it is preferable to crosslink a hydrophilic resin composition containing a hydrophilic polymer, a crosslinking agent, and a lipophilic polymer. The hydrophilic polymer can be insoluble in water by crosslinking.

  As such a hydrophilic resin composition, for example, a hydrophilic resin composition described in JP-A No. 2002-362052 can be mentioned. Specifically, a substituted or unsubstituted (meth) acrylamide, N-vinylformamide, N -Hydrophilic polymer obtained by copolymerization of vinylacetamide, (meth) acrylate having a hydroxyl group or acidic group, such as hydroxyethyl methacrylate, cross-linking such as epoxy resin or amino resin having two or more functional groups, or blocked isocyanate A hydrophilic resin composition comprising a lipophilic polymer such as an agent, a water-dispersed polyurethane resin, an acrylic latex, and a water-dispersed polyester resin is preferred.

  More preferred as the hydrophilic polymer is a hydrophilic polymer obtained by polymerizing one or more monomers selected from unsubstituted or substituted (meth) acrylamide, N-vinylformamide, and N-vinylacetamide as a main component. . Although the hydrophilic polymer mainly composed of these monomers has a high affinity for water, it has a low water absorption amount, so that it is difficult to swell, and the hydrophilicity and printing durability of the non-image area are good.

  The crosslinking agent is not particularly limited as long as it is a compound having two or more functional groups that crosslinks the hydrophilic polymer and makes it insoluble in water. However, the hydrophilicity of the non-image area, the lipophilicity of the image area, and the printing durability. From the viewpoint of properties and the like, it is preferably one or more selected from epoxy resins, amino resins, and blocked isocyanates.

More preferable as the lipophilic polymer is an average particle size of 0.005 to 0.5 μm, more preferably 0.010 to 0.3 μm, and a minimum film forming temperature of 50 ° C. or lower, more preferably 30 ° C. or lower. An aqueous emulsion type lipophilic polymer. In particular the water-dispersible polyurethane resins, acrylic latex, water dispersible polyester resin is preferable, and specific examples thereof include Vylonal ^TM series manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. SUPERFLEX ^TM series and Toyobo Corporation. When the average particle size is within this range, the hydrophilicity before energy irradiation is not lowered, and it is easy to cause a change during lipophilicity by energy irradiation, particularly heat, which is preferable. The average particle diameter of the lipophilic polymer can be generally measured by diluting with water and using a particle size measuring device (for example, “Microtrac”). In addition, the lipophilic polymer can be sliced after freezing and measured with a transmission electron microscope. This method is preferably used particularly when the average particle size is 0.010 μm or less. The minimum film-forming temperature refers to the minimum temperature at which an emulsion polymer is fused and formed into a film (film formation) when the dispersion solvent evaporates. The lower the minimum film-forming temperature, the more preferable it is because the change during lipophilicity is likely to occur due to energy irradiation, particularly heat. In addition, the minimum film-forming temperature is measured by a method based on ISO 2115, and a film-forming temperature (MFT) test apparatus manufactured by Imoto Seisakusho, for example, is used as a measuring machine.

  It is preferable that the compounding quantity of a crosslinking agent and a lipophilic polymer is 5-100 mass parts and 5-300 mass parts, respectively with respect to 100 mass parts of hydrophilic polymers. When the blending amount is within this range, the hydrophilicity of the non-image area, the lipophilicity of the image area, and the printing durability are improved, which is preferable. Applying and heating a hydrophilic resin composition prepared by mixing an aqueous solution or an emulsion-like hydrophilic polymer, a crosslinking agent and a lipophilic polymer while stirring directly on the support or on the underlayer, and heating the hydrophilic resin layer Is formed. Here, various surfactants may be added to the hydrophilic resin composition in order to expand the stability to printing conditions. Although there is no restriction | limiting in particular in the film thickness of this hydrophilic resin layer, As a film thickness after heat processing, about 0.5-10 micrometers is preferable normally, and 1-4 micrometers are especially preferable.

  In the above description, (meth) acryl and (meth) acrylate in (meth) acrylamide and (meth) acrylate mean acryl, methacryl, acrylate and methacrylate, respectively.

  As a method of heating a part of the hydrophilic resin layer of the present invention, a method of directly heating using a thermal head is also a preferred embodiment, but it is desirable to use laser light from the viewpoint of fineness.

  When laser light is used, a light-to-heat conversion material that converts light into heat is necessary. The light-to-heat conversion material is not particularly limited as long as it absorbs light and generates heat, and light in a wavelength region that is absorbed by the light-to-heat conversion material may be used as appropriate when the laser light is irradiated. Specific examples of photothermal conversion materials include cyanine dyes, polymethine dyes, phthalocyanine dyes, naphthalocyanine dyes, anthracocyanine dyes, porphyrin dyes, azo dyes, benzoquinone dyes, naphthoquinone dyes, dithiol metal complexes , Metal complexes of diamine, various pigments such as nigrosine, and carbon black. Among these light-to-heat conversion materials, light-to-heat conversion materials that absorb light in the wavelength region of 700 to 1100 nm are preferable from the viewpoints of handling in a bright room, output of a light source used in an exposure machine, and ease of use. More preferably, the photothermal conversion material is an infrared absorbing dye having an absorption maximum at 700 to 1100 nm. These photothermal conversion materials may be dissolved or dispersed in the hydrophilic resin composition.

[Printed circuit board manufacturing method]
Examples of specific preferred methods of the method of the present invention include 1) a step of irradiating a lithographic printing original plate having the property of changing the affinity for ink with energy irradiation according to a circuit pattern to prepare a lithographic printing plate, Subsequently, 2) a step of installing the obtained lithographic printing plate in a lithographic offset printing machine, 3) a step of supplying a conductive paste and a dampening solution onto the printing plate, and attaching the conductive paste in a circuit pattern, 4) A step of transferring the circuit pattern-like conductive pattern to the substrate via a blanket.

[Lithographic printing plate]
A lithographic printing plate suitable for the method of the present invention is a lithographic printing plate in which the hydrophilicity of the surface of the photosensitive layer at the irradiated part is changed to oleophilic. This lithographic printing plate can be printed without the development or wiping operation, with the ink adhering to the irradiated portion of the energy. The energy to be applied is preferably heat. For example, it is preferable to directly apply heat with a thermal head used in a thermal printer. The outermost surface of the original plate is changed to be oleophilic by bringing the thermal head, which is heated and heated by applying an electric potential, into direct contact with the original plate surface.

  When the lithographic printing plate precursor suitable for the method of the present invention contains the photothermal conversion material, it is also a preferred embodiment that the energy to be applied is light. In the light irradiation of the lithographic printing plate precursor suitable for the present invention, it is preferable to scan the convergent light at high speed from the point of irradiation speed, and it is easy to use. Also, a high-power light source is suitable as the light source. From this point, laser light, particularly infrared laser light having an oscillation wavelength in the wavelength range of 700 to 1100 nm, is preferable, for example, a high-power semiconductor of 830 nm. A laser or a 1064 nm YAG laser is preferably used. Exposure machines equipped with these lasers are already on the market as so-called thermal plate setters (exposure machines).

[Conductive paste]
In the method of the present invention, it is preferable to use a conductive paste as a printing ink. The conductive paste used in the present invention is not particularly limited, but preferably contains at least conductive particles and an organic resin. In order to form a fine wiring circuit, the conductive particles used are preferably metal particles having an average particle diameter of 100 nm or less and 1 nm or more, and the average particle diameter is 50 nm or less in order to reduce the conduction resistance of the wiring circuit. More preferably, it is 2 nm or more. The average particle diameter is measured with a scanning electron microscope by applying a thin conductive paste on a measuring table.

  Examples of the metal powder include gold, silver, copper, nickel, palladium and the like. These pastes can be prepared by mixing and dispersing these metal powders with an organic resin and a solvent. Examples of the organic resin include an epoxy resin, a phenol resin, a polyimide resin, a polyamide resin, a polyamideimide resin, a polyphenylene oxide resin, a polycyanate resin, and the like. The weight ratio of the metal powder to the organic resin is 70:30 to 99. A range of: 1 is preferred. Moreover, you may add a viscosity regulator and a reducing agent as needed.

  Examples of the solvent include a polyethylene glycol monomethyl ether solvent, a polyethylene glycol monomethyl ether acetate solvent, a polypropylene glycol monomethyl ether solvent, a polypropylene glycol monomethyl ether acetate solvent, an alcohol solvent, and a hydrocarbon solvent. The amount of these solvents used is usually 20 to 50% by weight in the conductive paste.

  Examples of the conductive paste that can be used in the method of the present invention include commercially available NPS, NPS-J, NPG-J, NPS-H, NPS-HS (Harima Kasei Co., Ltd.), and Dotite series (Fujikura Kasei Co., Ltd.). Etc. can also be illustrated. These can be used by adjusting to a desired viscosity by appropriately adding dilution or concentration with a solvent and adding a viscosity modifier.

[Printing method]
In the method of the present invention, a lithographic printing plate can be used as a mold, a conductive paste can be used as a printing ink, and a printed board can be formed by lithographic offset printing. Specifically, a lithographic printing plate whose affinity for ink has been changed to a circuit pattern by energy irradiation, preferably a development-less lithographic printing plate comprising a hydrophilic resin photosensitive layer whose irradiation area has been changed to oleophilicity by laser irradiation is commercially available. Installed on the lithographic offset printing press. Subsequently, a conductive paste and a fountain solution are supplied onto the printing plate, and the conductive paste is attached in a circuit pattern. The printed circuit board is produced by transferring the circuit pattern conductive pattern to the board through a rubber blanket. As a board | substrate used here, a copper-clad epoxy resin, a phenol resin, etc. can be used, and a flexible film-like thing may be used. Examples of the copper-clad epoxy resin and phenol resin include Sumitite ^TM PL / EL manufactured by Sumitomo Bakelite. As an example of a flexible substrate, Mitsui Chemicals, Inc. polyimide film, Neoprex ^TM, etc. are mentioned.

  As the lithographic offset printing press, a circular flatbed press, a rotary sheet-fed press, or a rotary press can be used, but if the substrate to be printed is a copper-clad epoxy resin or phenol resin substrate, it is rigid. It is preferable to use a flat table machine because it cannot be bent at the same time. In the case of a flexible substrate, a flatbed machine, a single wafer machine or a rotary machine can be used, but it is preferable to use a single wafer machine or a rotary machine from the viewpoint of productivity.

  The fountain solution is not limited as long as it is used for lithographic offset printing, and normal tap water, well water, ion exchange water, and distilled water can be used. Alcohols such as isopropyl alcohol and butyl alcohol, commercially available moisturizers or H liquids such as Astro Mark 3 of Nikken Chemical Research Co., Ltd., Ecology of Fuji Film Graphic Systems Co., Ltd. Can be used.

  By using the printed circuit board manufacturing method of the present invention, a high-definition and highly reproducible printed circuit board can be manufactured in a large amount at a low cost, with high productivity, and in an environment-friendly manner without developing waste liquid.

Hereinafter, the present invention will be described in more detail with reference to examples.
[Example 1]
(Conductive paste)
The following composition was mixed and dispersed to prepare a conductive paste ink.

Silver powder having an average particle size of 7 nm: 96 parts by weight phenolic resin (Mitsui Chemicals Co., MILEX ^TM XLC): 2 parts epoxy resin (manufactured by Nippon Kayaku Co., ^Ltd., EOCN TM 4400): 2 parts Diethylene glycol monomethyl ether acetate: 100 copies (preparation of lithographic printing plate)
Wire the following hydrophilic resin composition to a 0.28 mm thick aluminum plate coated with a 1 μm thick urethane resin (Mitsui Chemicals, Urethane Resin Olester ^TM UD350) using a wire bar in advance. After uniformly coating using a bar, it was dried at 120 ° C. for 1 hour to form a photosensitive layer having a thickness of about 2 μm.

Acrylamide: hydroxyethyl methacrylate = 90: 10 (weight ratio) hydrophilic polymer aqueous solution (solid content 10 wt%): 400 parts Methylated melamine resin (Mitsui Cytec Co., Ltd., Cymel ^TM 350, solid content 80 wt%) : 25 parts Water-dispersed urethane resin (Daiichi Kogyo Seiyaku Co., Ltd., Superflex ^™ 700, solid content 40 wt%): 100 parts Cyanine dye aqueous solution (Nippon Photosensitive Dye Co., Ltd., IR-125, solid content) 5 wt%): 100 parts Anionic surfactant (Pricesurf ^TM A212E manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: solid content 100 wt%): 1 part (Preparation of lithographic printing plate)
The original plate was scanned and irradiated with a semiconductor laser beam having a wavelength of 830 nm so as to have an irradiation energy density of 350 mJ / cm ² to draw a circuit pattern having a line width of 25 μm, and a lithographic printing plate was prepared.

(printing)
This printing plate was fixed as it was on a printing plate of a 4-color flatbed offset printing machine KF-423-GL manufactured by Dainippon Screen Mfg. Co., Ltd. without development. A 2% aqueous solution of Astro Mark 3 from Nikken Chemical Research Co., Ltd. was used as the fountain solution, and the conductive paste was prepared as the ink. After supplying dampening water and conductive paste to the printing plate, printing was performed on Sumitite ^TM PL manufactured by Sumitomo Bakelite. By supplying the substrates one after another, 100 printed boards could be manufactured. At this time, the line widths of all 100 printed boards were drawn at 27 ± 2 μm, and it was found that the line width was high definition and high reproducibility.

[Example 2]
A printing plate prepared in the same manner as in Example 1 was fixed to a plate cylinder of a 4-color rotary offset printing machine HB-5000ED manufactured by Tokyo Machine Works, Ltd. As the substrate to be printed, the same film substrate Neofrex ^TM , dampening water and conductive paste manufactured by Mitsui Chemicals, Inc. were prepared as in Example 1. After supplying dampening water and conductive paste to the printing plate, printing was performed by rotating the printing machine at 400 rpm. When the printed film substrate was observed, the line width was 27 ± 2 μm, and it was found that the film substrate had high definition and high reproducibility.

  By using the production method of the present invention, a high-definition, high-reproducibility printed circuit board can be produced in a large amount at a low cost by an environmentally friendly method free from development waste liquid.

Claims (10)

A method for producing a printed circuit board having a conductive circuit formed on an insulating substrate by a printing method, wherein a lithographic printing plate having a property that the affinity for ink is changed by energy irradiation is used. A method for producing a printed circuit board is as follows: 1) A process for producing a lithographic printing plate by irradiating energy according to a circuit pattern to a lithographic printing plate having the property that the affinity for ink changes with energy irradiation, and 2) obtained. The process of installing the lithographic printing plate on the lithographic offset printing machine, 3) The process of supplying the conductive paste and fountain solution onto the printing plate and attaching the conductive paste to the circuit pattern, 4) The circuit pattern The printed circuit board manufacturing method according to claim 1, further comprising a step of transferring the conductive pattern to the substrate through a blanket. The printed circuit board manufacturing method according to claim 1, wherein the energy for changing the affinity for ink is light. The printed circuit board manufacturing method according to claim 3, wherein the irradiated light is an infrared laser beam. The printed circuit board manufacturing method according to claim 1 or 2, wherein the energy for changing the affinity for ink is heat. The method for producing a printed circuit board according to any one of claims 1 to 5, wherein the lithographic printing original plate is a lithographic printing original plate comprising a hydrophilic resin having a cross-linked outermost layer and having a property of reducing hydrophilicity upon irradiation with energy. The hydrophilic polymer layer in which the cross-linked hydrophilic resin layer of the outermost surface layer is polymerized based on one or more monomers selected from unsubstituted or substituted (meth) acrylamide, N-vinylformamide, and N-vinylacetamide as a main component The printed circuit board manufacturing method according to claim 6, wherein the conductive polymer is crosslinked. The crosslinked hydrophilic resin layer of the outermost surface layer comprises an oleophilic polymer having an average particle diameter of 0.005 to 0.5 µm and a minimum film forming temperature of 50 ° C or lower. The printed circuit board manufacturing method of description. The printed circuit board manufacturing method according to claim 6, comprising a photothermal conversion material for converting light into heat in the crosslinked hydrophilic resin layer of the outermost surface layer. The printed circuit board manufacturing method according to claim 9, wherein the photothermal conversion material is an infrared absorbing dye having an absorption maximum at 700 to 1100 nm.