Method for manufacturing printed circuit board

Abstract

In the manufacture of printed circuit boards using a semi-additive process, a used removal solution for removing a nickel-chromium-containing layer (5) is brought into contact with a chelate resin having a functional group represented by the following formula (1) for regeneration. In formula (1), a plurality of Rs are identical divalent hydrocarbon groups having 1 to 5 carbon atoms, and a portion of the hydrogen atoms may be substituted with halogen atoms. [Chemical Formula 1]

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a printed wiring board.

[0002] This application claims priority based on Japanese application No. 2020-194324, filed on November 24, 2020, and cites all the contents described in the Japanese application. Background Art

[0003] As electronic devices become smaller and lighter, the wiring sections of printed wiring boards (PCBs) are becoming increasingly smaller. One method for miniaturizing the wiring sections of PCBs is to form a seed layer on the surface of an insulating resin layer, coat the entire surface except for the circuitry with a plating resist, and then selectively form a copper plating layer only on the circuitry by electroplating. After removing the plating resist, the seed layer is removed except for the circuitry, thereby forming a PCB (see Japanese Patent Application Laid-Open No. 2004-6773).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-6773 Summary of the Invention

[0007] The present invention discloses a method for manufacturing a printed circuit board having a conductive pattern including a plurality of wiring portions, comprising: a step of preparing an insulating base film having a nickel-chromium-containing layer directly or indirectly laminated on its surface; after preparing the base film, a step of directly or indirectly laminating a resist pattern on the surface of the nickel-chromium-containing layer; after laminating the resist pattern, a step of laminating a copper plating layer by electroplating on an area on the surface side of the nickel-chromium-containing layer where the resist pattern is not laminated; after laminating the copper plating layer, a step of removing the resist pattern; after removing the resist pattern, a step of removing the nickel-chromium-containing layer from an area on the nickel-chromium-containing layer where the copper plating is not laminated using a stripping solution; and a step of regenerating the used stripping solution obtained in the step of removing the nickel-chromium-containing layer by contacting the used stripping solution with a chelating resin, wherein the chelating resin has a functional group represented by the following formula (1).

[0008] [Chemical Formula 1]

[0009]

[0010] (In formula (1), a plurality of Rs are identical divalent hydrocarbon groups having 1 to 5 carbon atoms. Some of the hydrogen atoms in the hydrocarbon groups may be substituted with halogen atoms.)

[0011] Another method for manufacturing a printed circuit board disclosed in the present invention is a method for manufacturing a printed circuit board having a conductive pattern including multiple wiring portions, comprising: a process of preparing an insulating base film having a nickel-chromium-containing layer directly or indirectly laminated on the surface; after the process of preparing the above-mentioned base film, a process of directly or indirectly laminating a resist pattern on the surface of the above-mentioned nickel-chromium-containing layer; after the process of laminating the above-mentioned resist pattern, a process of laminating a copper plating layer on an area on the surface side of the above-mentioned nickel-chromium-containing layer where the resist pattern is not laminated by electroplating; after the process of laminating the above-mentioned copper plating layer, a process of removing the above-mentioned resist pattern; and after the process of removing the above-mentioned resist pattern, a process of removing the nickel-chromium-containing layer from an area on the above-mentioned nickel-chromium-containing layer where the copper plating is not laminated using a regeneration removal liquid, the above-mentioned regeneration removal liquid being regenerated by bringing the used removal liquid into contact with a chelating resin, the above-mentioned chelating resin being a functional group represented by the following formula (1).

[0012] [Chemical Formula 2]

[0013]

[0014] (In formula (1), a plurality of Rs are identical divalent hydrocarbon groups having 1 to 5 carbon atoms. Some of the hydrogen atoms in the hydrocarbon groups may be substituted with halogen atoms.)

[0015] In the present disclosure, “an insulating base film having a nickel-chromium containing layer directly laminated on the surface” means an insulating base film having a nickel-chromium containing layer laminated directly above the surface. “An insulating base film having a nickel-chromium containing layer indirectly laminated on the surface” means an insulating base film having a nickel-chromium containing layer laminated directly above the surface (for example) via one or more other layers such as a conductive layer. “A resist pattern directly laminated on the surface of the nickel-chromium containing layer” means a resist pattern laminated directly above the nickel-chromium containing layer. “A resist pattern indirectly laminated on the surface of the nickel-chromium containing layer” means a resist pattern layer laminated directly above the nickel-chromium containing layer (for example) via one or more other layers such as a conductive layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] [ Figure 1 ] Figure 1 This is a schematic cross-sectional view of a printed wiring board manufactured by the method for manufacturing a printed wiring board according to one embodiment of the present disclosure.

[0017] [ Figure 2 ] Figure 2 This is a flowchart showing the procedure of a method for manufacturing a printed wiring board according to one embodiment of the present disclosure.

[0018] [ Figure 3 ] Figure 3 It shows Figure 2A schematic cross-sectional view of a step of laminating a conductive layer in a method of manufacturing a printed wiring board.

[0019] [ Figure 4 ] Figure 4 It shows Figure 2 A schematic cross-sectional view of a process for directly or indirectly laminating a resist pattern in a method for manufacturing a printed wiring board.

[0020] [ Figure 5 ] Figure 5 It shows Figure 2 A schematic cross-sectional view of a copper plating layer lamination step in a method for manufacturing a printed wiring board.

[0021] [ Figure 6 ] Figure 6 It shows Figure 2 A schematic cross-sectional view of a step of removing a resist pattern in a method of manufacturing a printed wiring board.

[0022] [ Figure 7 ] Figure 7 It shows Figure 2 A schematic cross-sectional view of a step of removing a conductive layer in a method of manufacturing a printed wiring board. DETAILED DESCRIPTION

[0023] [Problems to be Solved by the Invention]

[0024] For example, in the manufacture of printed wiring boards, a seed layer is formed on a substrate, and a copper plating layer or the like is stacked thereon. The seed layer may include, for example, a layer containing nickel and chromium. Such a seed layer is partially removed during the manufacturing process, but a nickel-chromium-containing layer removing liquid is generally used for this removal. The nickel-chromium-containing layer removing liquid is a liquid for removing the nickel-chromium-containing layer. Hereinafter, it may be referred to simply as the removing liquid. Such a removing liquid cannot be reused. The reason for this is that when the seed layer is immersed in the removing liquid, the metal components of other layers of the printed wiring board are dissolved in the removing liquid, the metal concentration in the removing liquid increases, and as a result, the etching performance is reduced.

[0025] In particular, in a fine printed wiring board, a reduction in etching performance causes peeling of wiring portions, which in turn affects the performance of the circuit board.

[0026] The present disclosure has been made based on the above circumstances, and an object of the present disclosure is to provide a method for manufacturing a printed wiring board that can extend the life of a removing liquid and use a regenerated removing liquid obtained by regenerating the removing liquid to manufacture a printed wiring board in which peeling of wiring portions is suppressed.

[0027] [Effects of the Present Disclosure]

[0028] According to the present disclosure, it is possible to reuse the used removing liquid and extend the life of the removing liquid.

[0029] [Description of Embodiments of the Present Disclosure]

[0030] First, embodiments of the present disclosure are listed and described.

[0031] The present invention discloses a method for manufacturing a printed circuit board having a conductive pattern including a plurality of wiring portions, comprising: a step of preparing an insulating base film having a nickel-chromium-containing layer directly or indirectly laminated on its surface; after preparing the base film, a step of directly or indirectly laminating a resist pattern on the surface of the nickel-chromium-containing layer; after laminating the resist pattern, a step of laminating a copper plating layer by electroplating on an area on the surface side of the nickel-chromium-containing layer where the resist pattern is not laminated; after laminating the copper plating layer, a step of removing the resist pattern; after removing the resist pattern, a step of removing the nickel-chromium-containing layer from an area on the nickel-chromium-containing layer where the copper plating is not laminated using a stripping solution; and a step of regenerating the used stripping solution obtained in the step of removing the nickel-chromium-containing layer by contacting the used stripping solution with a chelating resin, wherein the chelating resin has a functional group represented by the following formula (1).

[0032] [Chemical Formula 3]

[0033]

[0034] (In formula (1), a plurality of Rs are identical divalent hydrocarbon groups having 1 to 5 carbon atoms. Some of the hydrogen atoms in the hydrocarbon groups may be substituted with halogen atoms.)

[0035] The removing solution used to remove the nickel-chromium containing layer usually contains hydrochloric acid, sulfuric acid, etc. In addition to nickel and chromium, the copper contained in the wiring portion is also dissolved to some extent in such a removing solution. When the concentration of copper ions in the liquid increases, the dissolution rate of copper is further accelerated. Therefore, the service life of the removing solution is determined by the concentration of copper ions in the removing solution. The inventors believe that in order to achieve a longer service life of the removing solution and to suppress the peeling of the manufactured circuit, it is necessary to keep the concentration of copper ions in the removing solution low, and have conducted in-depth research. As a result, it was found that by contacting the removing solution with a chelate resin having a functional group represented by the above-mentioned formula (1), the copper ions in the removing solution can be adsorbed on the chelate resin. The manufacturing method of the printed wiring board includes a step of regenerating the used removing solution by contacting the used removing solution with a chelate resin having a functional group represented by the above-mentioned formula (1) after the step of removing the above-mentioned nickel-chromium containing layer. The concentration of copper ions in the above-mentioned removing solution obtained by regeneration is reduced, so it can be reused as a regenerated removing solution, thereby extending the service life of the removing solution.

[0036] Preferably, the method further comprises the steps of laminating a conductive layer on the surface of the nickel-chromium containing layer after preparing the base film and before laminating the resist pattern, and removing the conductive layer after removing the resist pattern and before removing the nickel-chromium containing layer. Laminating the conductive layer on the surface of the nickel-chromium containing layer allows sufficient current to flow as a cathode in the subsequent step of laminating the copper plating layer.

[0037] Preferably, the regeneration removal solution obtained in the step of regenerating the used removal solution contains chloride ions and copper ions, has a pH of 1 or less, and has a copper ion concentration of 1 ppm to 2000 ppm. This method can effectively maintain the removal of nickel and chromium. Furthermore, since the regeneration removal solution is strongly acidic with a pH of 1 or less, the removal effect of the nickel-chromium containing layer can be further improved. Furthermore, since the copper ion concentration of the regeneration removal solution is within the above-mentioned range, the removal effect of the nickel-chromium containing layer can be improved, while the copper ion concentration in the regeneration removal solution can be maintained at a low level, thereby improving the effect of suppressing the peeling of the wiring portion and the effect of suppressing short circuits caused by the collapse of the wiring portion.

[0038] Preferably, in the manufacturing method of the printed circuit board disclosed in the present invention, the regenerated removal solution obtained in the process of regenerating the above-mentioned used removal solution further contains a pyridine compound, and the concentration of the above-mentioned pyridine compound exceeds 0 ppm and is below 5000 ppm. According to this method, the removal effect of nickel and chromium can be well maintained. In addition, in the above-mentioned removal solution, a part of the chelate resin having the functional group represented by the above-mentioned formula (1) decomposes to generate a pyridine compound as an impurity. The inventors found that: this impurity hinders the removal of the nickel-chromium containing layer. By making the concentration of the pyridine compound in the above-mentioned regenerated removal solution below 5000 ppm, the hindering effect of the above-mentioned pyridine compound on the removal of nickel and chromium can be reduced, and therefore the removal effect of nickel and chromium can be well maintained.

[0039] According to the present disclosure, the functional group is preferably a bis(2-pyridylmethyl)amino group. Since the chelate resin has the functional group represented by the formula (1), the removal effect of the nickel-chromium containing layer can be further improved.

[0040] In addition, another method for manufacturing a printed circuit board disclosed in the present invention is a method for manufacturing a printed circuit board having a conductive pattern including multiple wiring portions, comprising: a process of preparing an insulating base film having a nickel-chromium-containing layer directly or indirectly laminated on the surface; after the process of preparing the above-mentioned base film, a process of directly or indirectly laminating an anti-etching pattern on the surface of the above-mentioned nickel-chromium-containing layer; after the process of laminating the above-mentioned anti-etching pattern, a process of laminating a copper plating layer by electroplating on an area on the surface side of the above-mentioned nickel-chromium-containing layer where the anti-etching pattern is not laminated; after the process of laminating the above-mentioned copper plating layer, a process of removing the above-mentioned anti-etching pattern; and after the process of removing the above-mentioned anti-etching pattern, a process of removing the nickel-chromium-containing layer from an area on the above-mentioned nickel-chromium-containing layer where the copper plating is not laminated using a regenerated removal liquid, the above-mentioned regenerated removal liquid being regenerated by bringing the used removal liquid into contact with a chelating resin, the above-mentioned chelating resin being a functional group represented by the following formula (1).

[0041] [Chemical Formula 4]

[0042]

[0043] (In formula (1), a plurality of Rs are identical divalent hydrocarbon groups having 1 to 5 carbon atoms. Some of the hydrogen atoms in the hydrocarbon groups may be substituted with halogen atoms.)

[0044] The manufacturing method of this printed wiring board comprises a process of using a regenerated removing solution to remove the nickel-chromium containing layer in the region where the copper plating is not laminated among the above-mentioned nickel-chromium containing layer, thereby realizing the reuse of the used removing solution. In addition, in the manufacturing method of this printed wiring board, since the above-mentioned regenerated removing solution is regenerated by contacting the used removing solution with a chelate resin, the copper ions in the used removing solution are adsorbed on the chelate resin. As a result, since the concentration of the copper ions in the above-mentioned regenerated removing solution is reduced, the removal effect of the nickel-chromium containing layer can be improved, and the dissolution of the copper contained in the wiring portion in the process of removing the nickel-chromium containing layer can be suppressed. As a result, the regenerated removing solution can be used to manufacture a printed wiring board in which the peeling of the wiring portion is suppressed. Thus, the effective utilization of the used regenerated removing solution and the reduction of manufacturing cost can be realized.

[0045] " surface " in the disclosure refers to the face in the thickness direction outside when observing from the thickness direction center of basement membrane in printed wiring board, and does not limit the upper and lower relations when manufacturing or using of printed wiring board. In addition, " used removing solution (or used regeneration removing solution) " in the disclosure refers to that unused removing solution contains layer and is used 1 time at least in nickel-chromium removal operation, and concentration becomes the removing solution higher than the concentration of the cupric ion of unused removing solution. It should be noted that, when the concentration of cupric ion contained in the used regeneration removing solution is lower than the situation of pre-set concentration, also can not make chelating resin contact with used regeneration removing solution.

[0046] [Details of the embodiments of the present disclosure]

[0047] Hereinafter, a method for manufacturing a printed wiring board according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0048] <Method for Manufacturing Printed Wiring Board>

[0049] [First embodiment]

[0050] like Figure 1 As shown, the method for manufacturing a printed wiring board according to the first embodiment of the present disclosure is a method for manufacturing a printed wiring board 8 having a conductive pattern including an insulating base film 1 and a plurality of wiring portions 2 formed on at least one surface of the base film 1 .

[0051] In printed wiring board 8 manufactured using this method for manufacturing a printed wiring board, wiring portion 2 includes a nickel-chromium-containing layer 5 laminated on the surface of base film 1 and a copper plating layer 4 laminated on the surface of nickel-chromium-containing layer 5 by copper plating. This method for manufacturing a printed wiring board is particularly suitable for manufacturing fine-pitch printed wiring boards, in which multiple wiring portions 2 are small in width and arranged at narrow intervals. Nickel-chromium-containing layer 5 improves the adhesion between base film 1 and wiring portion 2, that is, improves the removal strength. Printed wiring board 8 can be configured to include a conductive layer 6 formed of the same metal as copper plating layer 4 (i.e., copper) laminated on the surface of nickel-chromium-containing layer 5.

[0052] Figure 2The sequence of the method for manufacturing the printed circuit board is shown. As the method for manufacturing the printed circuit board, a semi-additive method is used. The method for manufacturing the printed circuit board includes: preparing an insulating base film having a nickel-chromium containing layer directly or indirectly laminated on the surface (step S1); after the process of preparing the base film, laminating a resist pattern directly or indirectly on the surface of the nickel-chromium containing layer (step S3); after the process of laminating the resist pattern, laminating a copper plating layer by electroplating on the area on the surface side of the nickel-chromium containing layer where the resist pattern is not laminated (step S4); after the process of laminating the copper plating layer, removing the resist pattern (step S5); after the process of removing the resist pattern, removing the nickel-chromium containing layer from the area on the nickel-chromium containing layer where the copper plating is not laminated using a stripping solution (step S7); and after the process of removing the nickel-chromium containing layer, contacting the used regenerated stripping solution with a chelating resin to regenerate the stripping solution (step S8). The method for manufacturing a printed wiring board preferably further comprises, after the step of preparing the base film (step S1), a step of directly or indirectly laminating a conductive layer on the surface of the nickel-chromium-containing layer (step S2). Furthermore, when the conductive layer is formed, it is preferred that, after the step of removing the resist pattern (step S5), a step of removing the conductive layer (step S6) is included.

[0053] [Step of Preparing a Base Film]

[0054] In the base film preparation process of step S1, a base film laminated with a nickel-chromium-containing layer is prepared. This base film has insulating properties, and a nickel-chromium-containing layer 5 is laminated directly or indirectly on its surface. Since the nickel-chromium-containing layer 5 contains nickel and chromium, it can achieve good adhesion to the base film 1. Examples of methods for laminating the nickel-chromium-containing layer 5 include electroless plating, sputtering, vapor deposition, and coupling agent coating.

[0055] (Basement membrane)

[0056] The base film 1 is mainly composed of a synthetic resin and has electrical insulation properties. The base film 1 is used to form a conductive pattern. The base film 1 can be flexible. When the base film 1 is flexible, the printed wiring board 8 can be used as a flexible printed wiring board.

[0057] Examples of the synthetic resin include polyimide, polyethylene terephthalate, liquid crystal polymer, and fluororesin.

[0058] When the printed wiring board 8 is used as a flexible printed wiring board, the lower limit of the average thickness of the base film 1 is preferably 5 μm, more preferably 10 μm. On the other hand, the upper limit of the average thickness of the base film 1 is preferably 50 μm, more preferably 40 μm. When the average thickness of the base film 1 is less than the above lower limit, the insulation strength of the base film 1 may become insufficient. On the other hand, when the average thickness of the base film 1 exceeds the above upper limit, the printed wiring board may become unnecessarily thick, or the flexibility may become insufficient. "Average thickness" refers to the average value of the thickness measured at any five points.

[0059] In the step of preparing the base film in step S1, a base film 1 having a nickel-chromium containing layer 5 laminated on its surface is prepared. The nickel-chromium containing layer 5 preferably has high adhesion to the base film 1 and the conductive layer 6.

[0060] The lower limit of the average thickness of the nickel-chromium-containing layer 5 is preferably 2 nm, more preferably 4 nm. On the other hand, the upper limit of the average thickness of the nickel-chromium-containing layer 5 is preferably 30 nm, more preferably 20 nm. If the average thickness of the nickel-chromium-containing layer 5 does not meet the above lower limit, sufficient adhesion may not be achieved. On the other hand, if the average thickness of the nickel-chromium-containing layer 5 exceeds the above upper limit, manufacturing costs may be unnecessarily increased.

[0061] [Step of Laminating Conductive Layer]

[0062] In the process of stacking the conductive layer in step S2, as shown in FIG. Figure 3 As shown, a conductive layer 6 is laminated on the surface of the nickel-chromium containing layer 5. This conductive layer 6 allows sufficient current to flow as a cathode in the subsequent step S4 of laminating the copper plating layer.

[0063] The conductive layer 6 is preferably formed of the same metal as the copper plating layer 4 to improve adhesion with the copper plating layer 4 and to form a single piece with the copper plating layer 4 in the resulting printed wiring board 8 to form the wiring of the wiring portion 2. Examples of the material of the conductive layer 6 include metals such as copper, silver, platinum, and nickel, with copper being preferred due to its low electrical resistance and low cost.

[0064] The lower limit of the average thickness of the laminated conductive layer 6 is preferably 50 nm, more preferably 100 nm. On the other hand, the upper limit of the average thickness of the conductive layer 6 is preferably 2 μm, more preferably 1.5 μm. If the average thickness of the conductive layer 6 does not meet this lower limit, the conductivity of the conductive layer 6 becomes insufficient, and there is a possibility that the surface of the copper plating layer 4 to be laminated thereon may not be smoothed. On the other hand, if the average thickness of the conductive layer 6 exceeds this upper limit, there is a possibility that the copper plating layer 4 may be unnecessarily eroded during the step of removing the nickel-chromium-containing layer in step S6.

[0065] Examples of methods for laminating the conductive layer 6 include electroless plating, application, drying, and sintering of a metal fine particle dispersion containing dispersed metal fine particles, sputtering, and vapor deposition. Among these, the method of applying, drying, and sintering a metal fine particle dispersion is preferred because it allows for relatively easy and inexpensive lamination of a conductive layer 6 having a sufficient thickness to ensure conductivity.

[0066] The metal fine particle dispersion preferably contains metal particles that form the conductive layer 6, a dispersion medium for the metal fine particles, and a dispersant for uniformly dispersing the metal fine particles in the dispersion medium. By using a metal fine particle dispersion in which the metal fine particles are uniformly dispersed, the metal fine particles can be uniformly attached to the surface of the nickel-chromium-containing layer 5, thereby enabling the uniform deposition of the conductive layer 6.

[0067] As a method for applying the metal fine particle dispersion onto the surface of the nickel-chromium-containing layer 5, conventionally known coating methods such as spin coating, spray coating, bar coating, die coating, slit coating, roll coating, and dip coating can be used. Alternatively, the metal fine particle dispersion can be partially applied by, for example, screen printing or a dispenser.

[0068] The shorter the drying time of the metal particle dispersion coating, the smaller the porosity of the conductive layer 6 obtained by sintering the coating. Therefore, it is preferred to accelerate the drying of the metal particle dispersion by heating or blowing air, and more preferably, to dry the coating by blowing warm air over the metal particle dispersion coating. The warm air temperature is preferably set to a level that does not cause the solvent in the metal particle dispersion to boil. Specifically, the warm air temperature can be set, for example, to between 30°C and 80°C.

[0069] By heating the dried coating film of the metal fine particle dispersion, the dispersant and various additives in the metal fine particle dispersion evaporate or thermally decompose, and the remaining metal fine particles are sintered to laminate the conductive layer 6 .

[0070] The heating temperature for sintering the coating film of the metal fine particle dispersion is appropriately selected depending on the material of the metal fine particles, and is, for example, 150° C. or higher and 500° C. or lower.

[0071] [Resist Pattern Lamination Process]

[0072] In the process of laminating the resist pattern in step S3, after the process of preparing the above-mentioned base film, the resist pattern is directly or indirectly laminated on the surface of the above-mentioned nickel-chromium containing layer. The resist pattern 7 has a reverse shape of the conductive pattern. In the process of laminating the resist pattern, as shown in FIG. Figure 4 As shown, a resist pattern 7 is stacked on the surface of the conductive layer 6 by photolithography.

[0073] Examples of methods for laminating resist films include applying and drying a liquid resist composition and thermally pressing a sheet-like resist composition. Sheet-like resist compositions are, for example, dry films. Materials for such resist films include commercially available materials used as plating resist materials, such as those containing acrylic resins as their main component.

[0074] The openings in the resist pattern 7 correspond to the width of the wiring portion 2 in the conductive pattern. The lower limit of the average width of these openings is not particularly limited, but is preferably 5 μm, more preferably 6 μm. On the other hand, the upper limit of the average width of these openings is preferably 20 μm, more preferably 15 μm. By ensuring that the average width of the openings in the resist pattern 7 falls within this range, the effectiveness of this method for manufacturing a printed wiring board can be further enhanced for fine-pitch circuits.

[0075] [Copper plating layer lamination process]

[0076] In the step S4 of laminating the copper plating layer, after the step of laminating the resist pattern, the copper plating layer 4 is laminated by electroplating on the area on the surface side of the nickel-chromium containing layer 5 where the resist pattern 7 is not laminated. It should be noted that, when the conductive layer 6 is laminated in step S2, the copper plating layer 4 is laminated on the area on the surface of the conductive layer 6 where the resist pattern 7 is not laminated. In the step of laminating the copper plating layer 4, the nickel-chromium containing layer 5 and the conductive layer 6 are used as cathodes for electroplating, as shown in FIG. Figure 5 As shown, the copper plating layer 4 is laminated on the surface of the conductive layer 6 exposed from the resist pattern. The region of the surface of the conductive layer 6 exposed from the resist pattern corresponds to the opening of the resist pattern 7.

[0077] The metal laminated by electroplating is copper. Copper has low electrical resistance and is inexpensive. In addition, by using the same type of metal as that forming the conductive layer 6, it can be integrated with the conductive layer 6.

[0078] The plating solution used in the step of laminating the copper plating layer is not particularly limited, and for example, a known copper plating solution containing copper sulfate, copper pyrophosphate, or the like can be used.

[0079] The line width and spacing L / S (line and space) in the above-mentioned conductive pattern is preferably not less than 5μm / 5μm and not more than 20μm / 20μm. In the method for manufacturing the printed wiring board, even when manufacturing a printed wiring board having a fine pitch circuit such as (for example) a line width and spacing of L / S=10 / 10 or less, a fine printed wiring board that can suppress peeling and short circuiting of the wiring portion can be obtained. Therefore, in the method for manufacturing the printed wiring board, since the line width and spacing L / S in the above-mentioned conductive pattern are within the above-mentioned range, it can be used as a fine pitch circuit to exert a better inhibitory effect on peeling and short circuiting of the wiring portion. Here, "line width and spacing" refers to the size of the width [μm] of the wiring portion in the conductive pattern and the gap [μm] between the wiring portions.

[0080] [Step of Removing the Resist Pattern]

[0081] In the process of removing the resist pattern in step S5, after the process of laminating the copper plating layer, the resist pattern 7 is removed. Figure 6 As shown, the resist pattern 7 is dissolved and removed using a resist removing solution.

[0082] As the resist removing liquid, a resist removing liquid that dissolves the resist pattern 7 but does not dissolve the base film 1, the nickel-chromium containing layer 5, the conductive layer 6, and the copper plating layer 4 can be used. As such a resist removing liquid, for example, a known removing liquid containing 2-aminoethanol, tetramethylammonium hydroxide, an organic acid, or the like as a main component can be used.

[0083] [Step of Removing the Conductive Layer]

[0084] In the process of removing the conductive layer in step S6, the conductive layer 6 exposed by the removing liquid is dissolved and removed. Figure 7 As shown, the exposed areas of the conductive layer 6 are removed.

[0085] As the conductive layer removing solution used in the step of removing the conductive layer, for example, a sulfuric acid-hydrogen peroxide aqueous solution can be used. The sulfuric acid-hydrogen peroxide aqueous solution is sometimes called a Piranha solution.

[0086] [Step of Removing the Nickel-Chromium-Containing Layer]

[0087] In the process of removing the nickel-chromium containing layer in step S7, after the process of removing the above-mentioned conductive layer, a removing liquid is used to remove the nickel-chromium containing layer in the area of ​​the nickel-chromium containing layer 5 where the copper plating layer 4 is not stacked, that is, the exposed nickel-chromium containing layer 5. In this process, a removing liquid that corrodes nickel and chromium is used to dissolve and remove the nickel-chromium containing layer 5. As a method of dissolving, for example, the removing liquid can be contained in a liquid tank and the substrate can be immersed in the removing liquid. As the removing liquid, an unused removing liquid can be used, or a regenerated removing liquid described later can be used. The method of using the regenerated removing liquid will be described in the second embodiment. In this way, a conductive pattern having a plurality of wiring portions is manufactured by removing the area of ​​the nickel-chromium containing layer 5 that overlaps with the resist pattern 7 in a plan view. The wiring portion 2 after the process of removing the nickel-chromium containing layer is as shown in FIG. Figure 1 shown.

[0088] [Step of regenerating the removal solution]

[0089] In the process of regenerating the removing solution in step S8, after the process of removing the above-mentioned nickel-chromium containing layer, the used regenerating removing solution is contacted with a chelate resin, thereby regenerating the used regenerating removing solution. Specifically, in the process of regenerating the removing solution, after the process of removing the above-mentioned nickel-chromium containing layer, the used removing solution is recovered, and the above-mentioned recovered removing solution is contacted with a chelate resin.

[0090] Above-mentioned resin has the functional group represented by following formula (1).By making removing solution contact with this resin, can adsorb the cupric ion in the removing solution, therefore can keep the concentration of the cupric ion of the regenerated removing solution of gained lower.Thus, can when prolonging the life-span of removing solution, make nickel-chromium contain the removal effect of layer good, and can suppress the dissolving of the copper contained in the wiring portion in the operation of removing nickel-chromium containing layer.In addition, even under the situation of making fine printed wiring board, also can suppress the stripping of wiring portion.

[0091] [Chemical Formula 5]

[0092]

[0093] In the above formula (1), a plurality of R's are identical divalent hydrocarbon groups having 1 to 5 carbon atoms. Some of the hydrogen atoms in the above hydrocarbon groups may be substituted with halogen atoms.

[0094] Examples of the divalent hydrocarbon group having 1 to 5 carbon atoms represented by R include divalent chain hydrocarbon groups having 1 to 5 carbon atoms and divalent alicyclic hydrocarbon groups having 3 to 5 carbon atoms. The chain hydrocarbon group may be linear or branched.

[0095] Examples of the divalent chain hydrocarbon group include a divalent chain saturated hydrocarbon group and a divalent chain unsaturated hydrocarbon group.

[0096] Examples of the above-mentioned divalent chain saturated hydrocarbon groups include methylenediyl (-CH2-), ethylenediyl (-C2H4-), propylenediyl (-C3H6-), butanediyl (-C4H8-), dimethylethylenediyl (-C4H8-), dimethylmethylenediyl (-C3H6-), and methylethylenediyl (-C3H6-).

[0097] Examples of the above-mentioned divalent chain unsaturated hydrocarbon groups include: vinyldiyl (-C2H2-), propylenediyl (-C3H4-), butenediyl (-C4H6-), methylenemethylenediyl (-C2H4-), methyleneethylenediyl (-C3H4-), methylenepropylenediyl (-C4H6-), vinylethylenediyl (-C4H6-), acetylenediyl (-C2H2-), propynediyl (-C3H2-), butynediyl (-C4H4-), vinylethynyl (-C4H2-), ethynylpropylenediyl (-C5H4-), pentadiynediyl (-C5H2-), etc.

[0098] Examples of the divalent alicyclic hydrocarbon group include a divalent alicyclic saturated hydrocarbon group and a divalent alicyclic unsaturated hydrocarbon group.

[0099] Examples of the divalent alicyclic saturated hydrocarbon group include a cyclopropanediyl group (—C 3 H 4 —), a cyclobutanediyl group (—C 4 H 6 —), and a cyclopentanediyl group (—C 5 H 8 —).

[0100] Examples of the divalent alicyclic unsaturated hydrocarbon group include cyclopentenediyl (—C 5 H 6 —) and the like.

[0101] Examples of the halogen atom that may substitute for a part of the hydrogen atoms in the hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0102] As the functional group, bis(2-pyridylmethyl)amino is preferred. Since the chelate resin has the functional group represented by the formula (1), the removal effect of the nickel-chromium containing layer can be further improved.

[0103] As the base material of above-mentioned resin, for example can use polystyrene, styrene-divinylbenzene copolymer etc.As mentioned above, by using removing solution in the operation that removes above-mentioned nickel-chromium and contains layer, copper dissolves from stacked copper plating etc., thereby the concentration of the cupric ion in the removing solution increases.By using above-mentioned resin in the operation that makes used regeneration removing solution regeneration, the reduction effect excellence of the cupric ion in used regeneration removing solution.

[0104] As the method that resin is contacted with above-mentioned used regeneration removing liquid, for example can adopt the method for using known resin tower, in resin tower, fill above-mentioned resin.Then, used regeneration removing liquid is flowed into the resin tower, from used regeneration removing liquid, remove copper ion.In addition, as the method that resin is contacted with above-mentioned used regeneration removing liquid, also can not use the resin tower, but directly in used regeneration removing liquid, drop into above-mentioned resin, remove resin by filtering after the predetermined time, thereby carry out regeneration treatment.As the method that resin is contacted with above-mentioned used regeneration removing liquid, among these, preferably use the method for resin tower, it can make used regeneration removing liquid contact with resin efficiently and remove copper ion at short time.

[0105] Because above-mentioned resin can adsorb the amount of copper ion and be determined, so the copper ion concentration in the regeneration removing liquid can be adjusted by the ratio of used regeneration removing liquid and the amount of resin.As the usage amount of above-mentioned resin, with respect to the used regeneration removing liquid of 200L, be preferably below the 200L above the 50L.

[0106] The regeneration removal liquid can be used to remove the nickel-chromium-containing layer from a substrate having a nickel-chromium-containing layer and a copper-containing layer. The regeneration removal liquid can also be returned to the previous step of removing the nickel-chromium-containing layer. In this case, the removal step and the regeneration step can be repeated alternately on the same substrate to circulate the regeneration removal liquid. Alternatively, the regeneration removal liquid can be used in another subsequent step of removing the nickel-chromium-containing layer from the printed wiring board. Furthermore, the regeneration removal liquid can be mixed with unused or used removal liquid.

[0107] Next, the regeneration removal liquid will be described.

[0108] As described above, the "used regenerated removal solution" refers to a removal solution that has been used at least once in the nickel-chromium-containing layer removal process and has a copper ion concentration higher than that of the unused removal solution. As the unused removal solution, preferably, one containing chloride ions and having a pH of 1 or less. By removing the nickel-chromium-containing layer under a strongly acidic condition where the pH of the removal solution is 1 or less, the removal effect of the nickel-chromium-containing layer can be further improved. From the perspective of being able to remove the passivation film of the nickel-chromium-containing layer, hydrochloric acid is preferred among strong acids. As the unused removal solution, a hydrochloric acid aqueous solution having a concentration of 5% by mass or more and 20% by mass or less is preferred.

[0109] The regeneration removal liquid is preferably a hydrochloric acid aqueous solution having a concentration of 5% by mass or more and 20% by mass or less.

[0110] From the perspective of maintaining a good removal effect on the nickel-chromium-containing layer, it is preferred that the regeneration and removal solution contain chloride ions and copper ions, have a pH of 1 or less, and have a copper ion concentration of 1 ppm to 2000 ppm. By making the regeneration and removal solution highly acidic with a pH of 1 or less, the removal effect on the nickel-chromium-containing layer can be further improved. Furthermore, by keeping the copper ion concentration of the regeneration and removal solution within the above range, the nickel-chromium-containing layer can be effectively removed while maintaining a low copper ion concentration in the regeneration and removal solution, thereby improving the suppression of wiring peeling and the suppression of short circuits caused by wiring tipping.

[0111] It should be noted that, before the operation of removing solution regeneration, the operation of the copper ion concentration in the used regeneration removing solution of mensuration can be arbitrarily added. If the result of measuring is that copper ion concentration is below the above-mentioned upper limit, then the used regeneration removing solution can be directly used, and it is not necessary to necessarily implement the operation of making the removing solution regeneration next time.

[0112] In addition, it is preferred that the regeneration removal solution further contain a pyridine compound, with the concentration of the pyridine compound exceeding 0 ppm and being below 5000 ppm. This method can effectively maintain the removal of nickel and chromium. Furthermore, by setting the concentration of the pyridine compound in the regeneration removal solution to below 5000 ppm, the inhibitory effect of the pyridine compound on the removal of nickel and chromium can be reduced, thereby effectively maintaining the removal of nickel and chromium.

[0113] When the line width and spacing L / S in the conductive pattern is greater than or equal to 5μm / 5μm and less than or equal to 10μm / 10μm, the concentration of copper ions in the regeneration removal solution is more preferably greater than or equal to 30ppm and less than or equal to 1000ppm. When the line width and spacing L / S is greater than or equal to 10μm / 10μm and less than or equal to 15μm / 15μm, the concentration of copper ions in the regeneration removal solution is more preferably greater than or equal to 30ppm and less than or equal to 1500ppm. Furthermore, when the line width and spacing L / S is greater than or equal to 15μm / 15μm and less than or equal to 20μm / 20μm, the concentration of copper ions in the regeneration removal solution is more preferably greater than or equal to 30ppm and less than or equal to 2000ppm.

[0114] The relationship between the copper ion concentration in the regeneration removal solution and the line width and space L / S described above is the same for any removal solution.

[0115] When the chelate resin has the functional group represented by the above-mentioned formula (1), it is possible to produce a trace of pyridine compounds from the above-mentioned functional group in the regeneration removal solution. The above-mentioned pyridine compound is a compound obtained by decomposing the chelate resin with the functional group represented by the above-mentioned formula (1). The pyridine compound concentration in the above-mentioned regeneration removal solution is preferably 0ppm or exceeds 0ppm and is below 5000ppm. As mentioned above, due to the presence of pyridine compounds in the regeneration removal solution, the removal of nickel and chromium is hindered. Thus, by setting the pyridine compound concentration within the above-mentioned range, the hindering effect of the above-mentioned pyridine compound on the removal of nickel and chromium can be reduced, thereby the removal effect of nickel and chromium can be well maintained. In addition, when the line width and spacing L / S in the conductive pattern is more than 5μm / 5μm and less than 10μm / 10μm, the pyridine compound concentration in the above-mentioned regeneration removal solution is more preferably more than 10ppm and less than 3000ppm. When the line / space L / S is 10 μm / 10 μm or greater and less than 15 μm / 15 μm, the concentration of the pyridine compound in the regeneration removal solution is more preferably 10 ppm to 4000 ppm. Furthermore, when the line / space L / S is 15 μm / 15 μm to 20 μm / 20 μm, the concentration of the pyridine compound in the regeneration removal solution is more preferably 10 ppm to 5000 ppm.

[0116] The relationship between the concentration of the pyridine compound in the regeneration removal solution and the above-mentioned line width and space L / S is the same for any removal solution.

[0117] The method for manufacturing a printed wiring board according to the first embodiment includes, after removing the nickel-chromium containing layer, contacting the used regeneration removing solution with a chelate resin having a functional group represented by the formula (1), thereby regenerating the used regeneration removing solution. Since the concentration of the copper ions in the regeneration removing solution is reduced, the regeneration removing solution can be reused as the regeneration removing solution, thereby extending the life of the removing solution.

[0118] [Second embodiment]

[0119] The second embodiment of the present disclosure relates to a method for manufacturing a printed circuit board having a conductive pattern including a plurality of wiring portions, the method comprising: preparing an insulating base film having a nickel-chromium-containing layer directly or indirectly laminated on the surface; after preparing the base film, laminating a resist pattern directly or indirectly on the surface of the nickel-chromium-containing layer; after laminating the resist pattern, laminating a copper plating layer by electroplating on an area on the surface side of the nickel-chromium-containing layer where the resist pattern is not laminated; after laminating the copper plating layer, removing the resist pattern; and after removing the resist pattern, removing the nickel-chromium-containing layer from an area on the nickel-chromium-containing layer where the copper plating is not laminated using a regenerated removal liquid, wherein the regenerated removal liquid is regenerated by bringing the used removal liquid into contact with a chelating resin, wherein the chelating resin is a functional group represented by the above formula (1). Specifically, the method for manufacturing a printed wiring board according to the second embodiment differs from the method for manufacturing a printed wiring board according to the first embodiment in that a regeneration and removal liquid is used to remove the nickel-chromium-containing layer during the step of removing the nickel-chromium-containing layer. The regeneration and removal liquid in the second embodiment is as described above.

[0120] The manufacturing method of the printed wiring board that the second embodiment of the present disclosure relates to is by including the process of using a regeneration removing solution to remove the nickel-chromium containing layer in the region of the non-laminated copper coating among the above-mentioned nickel-chromium containing layer, thereby realizing the reuse of the used removing solution. In addition, in this manufacturing method of the printed wiring board, since the above-mentioned regeneration removing solution is regenerated by contacting the used removing solution with a chelate resin, the copper ions in the used removing solution are adsorbed on the chelate resin. As a result, the concentration of the copper ions in the above-mentioned regeneration removing solution is reduced, so that the removal effect of the nickel-chromium containing layer can be made good, and the dissolution of the copper contained in the wiring portion in the process of removing the nickel-chromium containing layer can be suppressed. As a result, the regeneration removing solution can be used to manufacture a printed wiring board that has suppressed the peeling of the wiring portion. Thus, the effective utilization of the used regeneration removing solution and the reduction of manufacturing cost can be realized.

[0121] [Other embodiments]

[0122] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The scope of the present disclosure is not limited to the configuration of the above-described embodiments, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0123] In the above embodiment, unused removing liquid or regenerated removing liquid is used as the removing liquid. However, any combination of unused removing liquid, regenerated removing liquid, and used regenerated removing liquid may be used.

[0124] Example

[0125] Hereinafter, the present disclosure will be described in more detail by way of examples, but the present disclosure is not limited to these examples.

[0126] [No.1~No.14]

[0127] A base film composed of a polyimide film with an average thickness of 25 μm was prepared. A conductive pattern consisting of 500 parallel wiring sections was formed on both sides of this base film using a semi-additive process. Specifically, a nickel-chromium-containing layer composed of nickel and chromium with an average thickness of 4 nm was first laminated (the base film preparation step). Next, a conductive layer composed of copper with an average thickness of 0.2 μm was laminated (the conductive layer lamination step).

[0128] Next, a photoresist film is laminated onto substantially the entire surface of the conductive layer using thermocompression bonding of an acrylic dry film resist. The photoresist film is then selectively exposed using a photomask, thereby forming portions that dissolve in a developer solution and portions that do not. The dissolved portions are then rinsed with a developer solution, thereby laminating a resist pattern having openings corresponding to the areas where the multiple wiring portions will be formed. The steps from laminating the photoresist film to rinsing the dissolved portions correspond to the resist pattern lamination process.

[0129] Next, the surface of the conductive layer after the resist pattern lamination step was subjected to electrolytic copper plating using a 25°C copper sulfate plating bath containing 90 g / L of copper sulfate pentahydrate to deposit a copper plating layer having an average thickness of 10 μm (copper plating layer lamination step).

[0130] Next, after the copper plating layer is laminated, the resist pattern is removed using a resist remover (a resist pattern removal step). The conductive layer in the conductive layer where the copper plating layer is not laminated is then removed using a conductive layer remover (a conductive layer removal step).

[0131] Next, the exposed nickel-chromium-containing layer is removed (nickel-chromium-containing layer removal step). In this nickel-chromium-containing layer removal step, the nickel-chromium-containing layer is removed using an unused removal solution. The unused removal solution consists of 15% hydrochloric acid, 10% sulfuric acid, a copper ion concentration of 50 ppm, and a pH of 1 or less. In this nickel-chromium-containing layer removal step, the substrate is immersed in the unused removal solution at a temperature of 45°C. The nickel-chromium-containing layer removal treatment lasts for 30 seconds.

[0132] Then, in the operation that makes the removing solution regeneration, in resin tower, fill the resin of 50L, make used removing solution pass through with 10L / minute, remove cupric ion.As resin, use 3 kinds of resins with two (2-pyridylmethyl) amino, iminodiacetic acid group and aminophosphoric acid group respectively.In addition, the pH of regenerating removing solution is all made as below 1.

[0133] The copper ion concentration in the regeneration removal solution was determined by quantitatively measuring the copper ion concentration in the sample solution using an inductively coupled plasma (ICP) emission spectrometer.

[0134] The pyridine compound concentration in the regeneration removal solution was quantified as follows: Using a UV-1800 UV-visible spectrophotometer manufactured by Shimadzu Corporation, the sample solution was diluted with water and the absorbance at 263 nm was measured. The pyridine compound concentration in the regeneration removal solution was then calculated using a pre-prepared calibration curve for bis(2-pyridylmethyl)amine.

[0135] By adjusting the copper ion concentration of used removal solution and in resin tower to the number of times of passing through resin etc., thereby change the copper ion concentration and the pyridine compound concentration of regeneration removal solution.The copper ion concentration and the pyridine compound concentration of the regeneration removal solution of gained are as shown in table 1 (No.2~No.14).

[0136] Next, the removal effect of the nickel-chromium containing layer was measured using the unused removing solution (No. 1) and the regenerated removing solution (samples No. 2 to No. 14).

[0137] First, printed wiring boards (No. 1 to No. 14) with varying line widths and spacings (L / S) [μm / μm] were fabricated. The fabrication process was the same as that used to obtain the regeneration and removal solution in the previous examples. However, the size of the openings in the resist pattern was adjusted to vary the line widths and spacings.

[0138] For No. 1 to No. 14 obtained in the above-mentioned step of removing the conductive layer, the step of removing the nickel-chromium-containing layer was carried out using unused removing liquid (No. 1) and regenerated removing liquid (No. 2 to No. 14). It should be noted that the regenerated removing liquid was not mixed with unused removing liquid or used removing liquid; only the regenerated removing liquid was used. It should be noted that the step of removing the nickel-chromium-containing layer was carried out in the same manner as the above-mentioned step of removing the nickel-chromium-containing layer, except that unused removing liquid (No. 1) and regenerated removing liquid (No. 2 to No. 14) were used.

[0139] The printed wiring boards of Samples No. 1 to No. 14 obtained after the step of removing the nickel-chromium containing layer were evaluated for the occurrence rate of peeling of the wiring portion and the occurrence rate of short circuits caused by nickel-chromium containing layer residues.

[0140] [evaluate]

[0141] (Incidence rate of peeling of wiring part)

[0142] The number of printed wiring boards No. 1 to No. 14 where peeling occurred was detected by visual inspection, and the rate of occurrence of peeling in the wiring portion [%] was determined.

[0143] (Short circuit occurrence rate caused by nickel-chromium containing layer residue)

[0144] The number of short circuits in the printed wiring boards No. 1 to No. 14 was measured by electrical inspection, and the incidence rate [%] of short circuits caused by the nickel-chromium containing layer residue was determined.

[0145] Table 1 shows the evaluation results of the occurrence rate of peeling of the wiring portion and the occurrence rate of short circuits caused by the nickel-chromium containing layer residue.

[0146] [Table 1]

[0147]

[0148] As shown in Table 1, the wiring portion of Nos. 2 to 12, which used a regeneration removal solution regenerated with a chelate resin containing a bis(2-pyridylmethyl)amino group in the nickel-chromium containing layer removal process, exhibited a low rate of wiring portion peeling, resulting in excellent results. In particular, no wiring portion peeling or short circuits caused by nickel-chromium containing layer residue were observed in Nos. 2, 4, 5, 11, and 12. The copper ion concentration in the regeneration removal solution for Nos. 2, 4, 5, 11, and 12 was between 50 ppm and 2000 ppm, and the pyridine compound concentration was below 5000 ppm.

[0149] On the other hand, the wiring portions of No. 13 and No. 14, which used a regeneration removal solution regenerated by a chelate resin having an iminodiacetic acid group or an aminophosphoric acid group in the step of removing the nickel-chromium containing layer, had a high rate of peeling.

[0150] As described above, the method for manufacturing a printed wiring board disclosed herein can maintain a low copper ion concentration in the regeneration removal solution. As a result, the nickel-chromium-containing layer can be effectively removed while simultaneously suppressing the dissolution of copper contained in the wiring during the nickel-chromium-containing layer removal process. Therefore, it can be seen that the life of the removal solution can be extended, and even when manufacturing fine printed wiring boards, printed wiring boards can be obtained in which peeling of the wiring is suppressed.

[0151] Explanation of symbols

[0152] 1 basement membrane

[0153] 2 Wiring section

[0154] 4 Copper plating

[0155] 5Nickel-chromium containing layer

[0156] 6 conductive layer

[0157] 7Resist pattern

[0158] 8Printed circuit boards

Claims

1. A method for manufacturing a printed wiring board having a conductive pattern including a plurality of wiring portions, comprising: A step of preparing an insulating base film having a nickel-chromium containing layer directly or indirectly laminated on the surface; After the step of preparing the base film, a step of directly or indirectly laminating a resist pattern on the surface of the nickel-chromium containing layer; After the step of laminating the resist pattern, a step of laminating a copper plating layer by electroplating on a region on the surface side of the nickel-chromium containing layer where the resist pattern is not laminated; a step of removing the resist pattern after laminating the copper plating layer; After the step of removing the resist pattern, removing the nickel-chromium containing layer in a region of the nickel-chromium containing layer where the copper plating layer is not stacked, using a removing solution; as well as a step of regenerating the used removing solution obtained in the step of removing the nickel-chromium containing layer by contacting the used removing solution with a chelate resin, The chelate resin has a functional group represented by the following formula (1): [Chemical Formula 1] In formula (1), a plurality of Rs are identical divalent hydrocarbon groups having 1 to 5 carbon atoms, and a portion of hydrogen atoms in the hydrocarbon group may be substituted with halogen atoms.

2. The method for manufacturing a printed circuit board according to claim 1, further comprising: a step of laminating a conductive layer on a surface of the nickel-chromium containing layer after the step of preparing the base film and before the step of laminating the resist pattern; as well as A step of removing the conductive layer after the step of removing the resist pattern and before the step of removing the nickel-chromium containing layer.

3. The method for manufacturing a printed wiring board according to claim 1 or claim 2, wherein: The regenerated removing solution obtained in the step of regenerating the used removing solution contains chloride ions and copper ions, has a pH of 1 or less, and has a copper ion concentration of 1 ppm to 2000 ppm.

4. The method for manufacturing a printed wiring board according to claim 3, wherein: The regenerated removing liquid obtained in the step of regenerating the used removing liquid further contains a pyridine compound, and the concentration of the pyridine compound is greater than 0 ppm and is 5000 ppm or less.

5. The method for manufacturing a printed wiring board according to claim 1 or claim 2, wherein: The functional group is bis(2-pyridylmethyl)amino.

6. The method for manufacturing a printed wiring board according to claim 3, wherein: The functional group is bis(2-pyridylmethyl)amino.

7. The method for manufacturing a printed wiring board according to claim 4, wherein: The functional group is bis(2-pyridylmethyl)amino.

8. A method for manufacturing a printed wiring board having a conductive pattern including a plurality of wiring portions, comprising: A step of preparing an insulating base film having a nickel-chromium containing layer directly or indirectly laminated on the surface; After the step of preparing the base film, a step of directly or indirectly laminating a resist pattern on the surface of the nickel-chromium containing layer; After the step of laminating the resist pattern, a step of laminating a copper plating layer by electroplating on a region on the surface side of the nickel-chromium containing layer where the resist pattern is not laminated; After laminating the copper plating layer, removing the resist pattern; and After the step of removing the resist pattern, a step of removing the nickel-chromium containing layer in a region of the nickel-chromium containing layer where the copper plating layer is not laminated is performed using a regeneration removal solution. The regenerated removal solution is regenerated by contacting the used removal solution with a chelating resin. The chelating resin is a functional group represented by the following formula (1): [Chemical Formula 2] In formula (1), a plurality of Rs are identical divalent hydrocarbon groups having 1 to 5 carbon atoms, and a portion of hydrogen atoms in the hydrocarbon group may be substituted with halogen atoms.

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