Manufacturing method of printed circuit boards

Abstract

The present invention provides a method for manufacturing a printed circuit board having a conductor circuit surface that has a roughened shape with excellent adhesion to the insulating layer, formed by creating fine irregularities on the surface of the conductor circuit, and having a conductor circuit surface with extremely small reduction in the amount of conductor circuit. [Solution] A method for manufacturing a printed wiring board having a conductor circuit surface in which fine irregularities are formed on the surface of the conductor circuit, comprising: forming a conductor circuit on an insulating layer; immersing the conductor circuit in a stearic acid solution; removing the conductor circuit from the stearic acid solution; washing the conductor circuit removed from the stearic acid solution with water; drying the conductor circuit after washing with water; plasma treating the dried conductor circuit with an oxygen-containing plasma; and reducing the conductor circuit after plasma treatment.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a printed wiring board. More specifically, it relates to a method for manufacturing a printed wiring board having a roughened conductor circuit surface formed by forming fine irregularities on the surface of the conductor circuit.

Background Art

[0002] With the rapid progress of narrowing the pitch of wiring (fine wiring), a micro-etching agent capable of forming a roughened shape excellent in adhesion to resin with a smaller etching amount, and a method for roughening the copper surface using the micro-etching agent have been proposed (Patent Document 1). Such a micro-etching agent contains an organic acid, cuprous ions, and halide ions, and the molar concentration of the halide ions is set to 0.005 to 0.1 mol / L.

[0003] FIG. 3 is a graph showing the results of roughening the copper surface using such a micro-etching agent. As shown in FIG. 3(a), the method for roughening the copper surface using a micro-etching agent with a small content of halide ions shows a particularly high peel strength at a low etching amount and can form a roughened shape excellent in adhesion to resin. Also, as shown in FIG. 3(b), by the method for roughening the copper surface using a micro-etching agent with a small content of halide ions, the roughening treatment of the copper surface can be carried out with a low etching amount, and a sample having a solder resist layer formed on a copper layer with high initial adhesion and excellent moisture absorption durability can be provided.

[0004] In this method of roughening a copper surface using a micro-etching agent, the copper surface is roughened by contacting it with a predetermined micro-etching agent. In this copper surface roughening method, if the etching amount is excessively small, a sufficient roughened shape may not be formed on the copper surface; therefore, an etching amount of 0.01 μm or more is preferable. On the other hand, in this copper surface roughening method using a micro-etching agent, when the etching amount is less than 0.5 μm, a roughened shape with particularly excellent adhesion between the resin and the copper surface is formed. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-59962 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the technology disclosed in Patent Document 1 roughens the surface of the conductor circuit by etching it with a predetermined etching agent. As a result, the technology disclosed in Patent Document 1 reduces the width and thickness of the conductor circuit due to the roughening treatment of the conductor circuit surface by etching. In other words, because the technology disclosed in Patent Document 1 employs a roughening treatment of the conductor circuit surface by etching, it is not possible to manufacture printed wiring boards having conductor circuits whose width and thickness are formed according to the preset design values. In other words, the technology disclosed in Patent Document 1 has the problem that, in addition to the predetermined design values ​​of the conductor circuit, the printed circuit board must be manufactured by roughening the surface of the conductor circuit while taking into account the reduction in the width and thickness of the conductor circuit due to the roughening treatment of the conductor circuit surface by etching. From this technical standpoint, the present invention aims to provide a method for manufacturing a printed wiring board having a conductor circuit surface that can form a roughened shape with excellent adhesion to an insulating layer by forming fine irregularities on the surface of the conductor circuit, and that has an extremely small reduction in the amount of conductor circuit. [Means for solving the problem]

[0007] The present invention relates to a method for manufacturing a printed circuit board, which comprises forming a conductor circuit on an insulating layer, immersing the conductor circuit in a stearic acid solution, removing the conductor circuit from the stearic acid solution, washing the conductor circuit removed from the stearic acid solution with water, drying the conductor circuit after washing, plasma treating the dried conductor circuit with an oxygen-containing plasma, and reducing the conductor circuit after plasma treatment. [Brief explanation of the drawing]

[0008] [Figure 1A] This is a cross-sectional view illustrating a conductor circuit of a printed circuit board manufactured by the printed circuit board manufacturing method according to the present invention. [Figure 1B] This is an enlarged cross-sectional view illustrating the conductive circuit of a printed circuit board manufactured by the printed circuit board manufacturing method according to the present invention. [Figure 1C] This is a conceptual diagram illustrating the process by which a printed circuit board is manufactured using the method for manufacturing printed circuit boards according to the present invention. [Figure 2A] This is a cross-sectional view illustrating one embodiment of the method for manufacturing a printed circuit board according to the present invention. [Figure 2B] This is a cross-sectional view illustrating one embodiment of the method for manufacturing a printed circuit board according to the present invention. [Figure 2C] This is a cross-sectional view illustrating one embodiment of the method for manufacturing a printed circuit board according to the present invention. [Figure 2D] This is a cross-sectional view illustrating one embodiment of the method for manufacturing a printed circuit board according to the present invention. [Figure 2E] This is a cross-sectional view illustrating one embodiment of the method for manufacturing a printed circuit board according to the present invention. [Figure 2F]It is a cross-sectional view for explaining an embodiment of a method for manufacturing a printed wiring board according to the present invention. [Figure 2G] It is a cross-sectional view for explaining an embodiment of a method for manufacturing a printed wiring board according to the present invention. [Figure 2H] It is a cross-sectional view for explaining an embodiment of a method for manufacturing a printed wiring board according to the present invention. [Figure 2I] It is a cross-sectional view for explaining an embodiment of a method for manufacturing a printed wiring board according to the present invention. [Figure 2J] It is a cross-sectional view for explaining an embodiment of a method for manufacturing a printed wiring board according to the present invention. [Figure 2K] It is a cross-sectional view for explaining an embodiment of a method for manufacturing a printed wiring board according to the present invention. [Figure 2L] It is a cross-sectional view for explaining an embodiment of a method for manufacturing a printed wiring board according to the present invention. [Figure 3] It is a graph showing the result of roughening the copper surface using a micro-etching agent in a conventional method for roughening the copper surface.

Embodiments for Carrying Out the Invention

[0009] <Regarding the printed wiring board manufactured by the method for manufacturing a printed wiring board according to the present invention> An embodiment of the method for manufacturing a printed wiring board according to the present invention will be described with reference to the drawings. In the examples shown in FIGS. 1 to 2, for the dimensions of each member, particularly the dimensions in the height direction, in order to better understand the features of the present invention, they are described with dimensions different from the actual dimensions.

[0010] FIG. 1 is a schematic diagram for explaining an embodiment of a printed wiring board manufactured by the method for manufacturing a printed wiring board according to the present invention. As shown in FIG. 1A, the printed wiring board 10 manufactured by the method for manufacturing a printed wiring board according to the present invention includes a conductor circuit 100 and an insulating layer 101. The conductor circuit 100 included in the printed wiring board 10 is formed on the insulating layer surface of the insulating layer 101.

[0011] The printed wiring board 10 may be a printed wiring board with a core, which is formed by alternately laminating a conductor circuit 100 and an insulating layer 101 on one or both sides of a core substrate (not shown). When forming the conductor circuits 100 on both sides of the core substrate, the conductor circuits 100 facing each other through the core substrate may be connected via through-hole conductors (not shown). Further, the printed wiring board 10 may be a coreless printed wiring board formed by alternately laminating the conductor circuit 100 and the insulating layer 101 on a support plate (not shown) and then removing the support plate.

[0012] Below the insulating layer 101 of the printed wiring board 10, a plurality of other conductor circuits 100 and insulating layers 101 may be alternately provided. The insulating layer 101 on which the conductor circuit 100 is formed can be composed of, for example, a resin composition containing an inorganic filler such as silica or alumina and an epoxy resin. The conductor circuit 100 formed on the insulating layer 101 may be composed of, for example, an electrolytic copper plating layer formed by a well-known semi-additive method or the like.

[0013] On the insulating layer 101, a ground layer (not shown) may be formed in addition to the conductor circuit 100. The ground layer may be formed along the conductor circuit 100 and is formed so as not to be electrically connected to the conductor circuit 100. Also, a solder resist layer (not shown) can be provided on the insulating layer surface of the insulating layer 101 located at the uppermost position and on the surface of the conductor circuit 100 formed on the insulating layer surface of the insulating layer 101.

[0014] Figure 1B is an enlarged cross-sectional view illustrating one embodiment of a conductor circuit 100 of a printed circuit board 10 manufactured by the printing circuit board manufacturing method according to the present invention, and shows the microstructure of the surface of the conductor circuit 100 in region R of the conductor circuit surface. As shown in Figure 1B, the surface of the conductor circuit 100 has a plurality of fine irregularities consisting of protrusions 110 and recesses 111. That is, the surface of the conductor circuit 100 has fine irregularities and is sufficiently roughened. The cross-sectional shape of the protrusions 110 can be, for example, approximately triangular, approximately trapezoidal, or approximately rectangular.

[0015] Here, the distance from the lower surface 112 of the recess 111 to the upper surface 113 of the protrusion 110 of the conductor circuit 100 of the printed wiring board 10 manufactured by the printed wiring board manufacturing method according to the present invention corresponds to the height H of the protrusion 110. The height H of the protrusion 110 can be appropriately set by the stearic acid content in the stearic acid solution immersion step and various conditions in the plasma treatment step in the printed wiring board manufacturing method described later, but it is preferably 1 to 50 nm, and more preferably 5 to 30 nm.

[0016] A printed circuit board 10 having such a conductor circuit 100 has a stable structure that ensures sufficient adhesion with the insulating layer 101 and resin material such as solder resist laminated on the surface of the conductor circuit 100. Furthermore, the printed circuit board 10 has a small reduction in the thickness and height of the conductor circuit 100 due to the roughening treatment of the conductor circuit, and can adequately accommodate fine wiring and high functionality.

[0017] In other words, according to the method for manufacturing a printed circuit board according to the present invention, fine irregularities are formed on the surface of the conductor circuit 100, and the surface of the conductor circuit 100 is sufficiently roughened, thereby enabling the manufacture of a printed circuit board 10 that has sufficient adhesion to the insulating layer 101, solder resist, and other resin materials laminated on the surface of the conductor circuit 100. As a result, the printed circuit board 10 having such a structure does not suffer from quality degradation that causes voids due to air bubbles remaining because of haloing between the insulating layer 101 and the conductive circuit 100. Furthermore, the printed circuit board 10 does not experience problems such as delamination at the interface between the insulating layer 101 and the copper wiring pattern constituting the conductive circuit 100 due to the heat generated when electronic components are mounted on the printed circuit board 10.

[0018] Figure 1C is a conceptual diagram showing the process by which a printed circuit board 10 is manufactured by the printing circuit board manufacturing method according to the present invention. As shown in Figure 1C (right side), the conductor circuits 100 of the printed circuit board 10 can be obtained by applying a roughening treatment to the surface of the conductor circuits 100X before the roughening treatment, which includes stearic acid immersion treatment, water washing / drying, plasma treatment, and reduction treatment. The conductor circuits 100 of the printed circuit board 10 shown in Figure 1C have substantially the same shape as the conductor circuits 100X before the roughening treatment, in terms of width and thickness (height). In other words, the conductor circuit 100 of the printed circuit board 10 manufactured by the printing circuit board manufacturing method according to the present invention can adequately accommodate narrower wiring pitches (fine wiring) without any significant thinning of the wiring constituting the conductor circuit 100.

[0019] The height H of the protrusions 110 formed on the conductor circuit 100 of the printed circuit board 10 manufactured by the printing circuit board manufacturing method according to the present invention is approximately the same as the height of the protrusions formed on the conductor circuit 100X before the roughening treatment. This is because, in the printing circuit board manufacturing method according to the present invention, the conductor circuit 100 formed by the roughening treatment of the conductor circuit surface is not subjected to etching treatment, unlike in the prior art, and therefore is not subjected to corrosion, dissolution, etc. of the conductor circuit 100X that occurs as the etching treatment progresses.

[0020] On the other hand, as shown in Figure 1C (left side), the conductor circuit 200 of a conventional printed circuit board 20 can be obtained by applying the roughening treatment of the conductor circuit surface using a conventional method for manufacturing printed circuit boards to the conductor circuit 100X before the roughening treatment. The conductor circuit 200 of the printed circuit board 20 shown in Figure 1C can be obtained by etching the surface of the conductor circuit 100X before the roughening treatment. After the roughening treatment, the conductor circuit 200 has the same shape, but with a significantly reduced width and thickness (height) compared to the conductor circuit 100X before the roughening treatment. In other words, the conductor circuits 200 of a printed circuit board 20 manufactured by a conventional printed circuit board manufacturing method suffer from thinning of the wiring constituting the conductor circuit, and are therefore unable to adequately accommodate narrower wiring pitches (fine wiring). Next, from this technical standpoint, the method for manufacturing a printed circuit board according to the present invention will be described in detail below.

[0021] <Regarding one embodiment of the method for manufacturing a printed circuit board according to the present invention> Figures 2A to 2L are cross-sectional views illustrating one embodiment of the method for manufacturing a printed circuit board according to the present invention. Hereinafter, one embodiment of the method for manufacturing a printed circuit board according to the present invention will be described with reference to Figures 2A to 2L.

[0022] First, as shown in Figure 2A, an insulating layer 101 on which a seed layer 102 is formed is prepared. That is, the seed layer 102 is formed on the surface of the insulating layer 101. The insulating layer 101 is a resin composition containing an inorganic filler such as silica or alumina and an epoxy resin, and specifically, it may be an electrical insulating material in which glass cloth is impregnated with an epoxy resin, a thermosetting resin such as bismaleimidotriazine resin. The seed layer 102 may be formed from an electroless copper plating film after the surface of the insulating layer 101 has been roughened with a permanganate solution.

[0023] Next, as shown in Figure 2B, a plurality of plating resists 103 are formed on the surface of the seed layer 102 of the insulating layer 101. Adjacent plating resists 103 and the other plating resist form a recess 104 for forming a conductor circuit 100X before roughening treatment.

[0024] The gap formed between the right-hand wall surface of one adjacent plating resist 103 and the left-hand wall surface of the plating resist 103 facing the right-hand wall surface of the said plating resist 103 corresponds to the width of the conductor circuit 100X before roughening treatment. The gap formed between the right-hand wall surface of one plating resist 103 and the left-hand wall surface of the other plating resist 103 can be appropriately set according to the shape of the conductor circuit 100X before roughening treatment. The gap formed between the right-hand wall surface of one adjacent plating resist 103 and the left-hand wall surface of the other plating resist 103 facing the right-hand wall surface of the said plating resist 103 can be 1 to 20 μm, depending on the width of the conductor circuit 100X before roughening treatment.

[0025] Next, as shown in Figure 2C, a conductor circuit 100X before roughening treatment is formed in the recess 104 for forming the conductor circuit. That is, an electrolytic copper plating layer 105 made of electrolytic copper plating is formed inside the recess 104 for forming the conductor circuit. The thickness of the conductor circuit 100X before roughening treatment formed inside the recess 104 for forming the conductor circuit may be 5 to 50 μm, preferably 10 to 30 μm. The conductor circuit 100X before roughening may be formed from a pad portion and a wiring portion. A ground layer (not shown) may also be formed together with the conductor circuit 100X before roughening.

[0026] Here, a direct current is used to deposit the electrolytic copper plating layer 105 that constitutes the conductor circuit 100X before roughening treatment. The current density of the direct current applied to form the electrolytic copper plating layer 105 that constitutes the conductor circuit 100X before roughening treatment is 1.0 to 10.0 A / dm². 2It is preferable that this is the case. The time for which a DC current is applied to deposit the electrolytic copper plating layer 105 that constitutes the conductor circuit 100X before roughening treatment is sufficient to form a predetermined thickness of the conductor circuit 100X before roughening treatment, and can be appropriately set depending on the form of the conductor circuit 100X before roughening treatment.

[0027] Next, as shown in Figure 2D, the plating resist 103 formed on the surface of the seed layer 102 of the insulating layer 101 is removed from the seed layer 102. By removing the plating resist 103 from the seed layer 102, the surfaces of each seed layer 102 that were located beneath the plating resist 103 are exposed. In addition to the top surface of the conductor circuit 100X before roughening treatment, the sides of the conductor circuit 100X before roughening treatment are also exposed.

[0028] Next, as shown in Figure 2E, the seed layer 102 formed on the insulating layer 101 is removed. The seed layer 102 is removed by etching. As a result, the insulating layer surface of the insulating layer 101 is exposed. The conductor circuit 100X before roughening treatment is formed on the insulating layer surface of the insulating layer 101.

[0029] Next, as shown in Figure 2F, the formed conductor circuit 100X before roughening treatment is immersed in a stearic acid solution. Immersion of the conductor circuit 100X before roughening treatment in the stearic acid solution 106 can be performed, for example, by pouring the stearic acid solution 106 into a container to form a stearic acid solution bath, and then immersing the conductor circuit 100X before roughening treatment in the stearic acid solution bath. The time for immersing the conductor circuit 100X before roughening treatment in the stearic acid solution bath can be set considering the concentration of the stearic acid solution 106, the shape of the conductor circuit 100X before roughening treatment, etc.

[0030] Alternatively, immersing the conductor circuit 100X before roughening treatment in the stearic acid solution 106 may be performed by spraying the stearic acid solution 106 onto the surface of the conductor circuit 100X before roughening treatment using a spray method or the like. The stearic acid solution may contain components such as sodium salts, potassium salts, or ammonium salts of organic acids as needed.

[0031] Here, the concentration of stearic acid solution 106 is 1.0 × 10⁶. -5 ~1.0×10 -2 It is preferable that the concentration is (mol / L). The concentration of stearic acid solution 106 is 1.0 × 10⁶. -5 A concentration of (mol / L) or higher is preferable because it allows the stearic acid contained in the stearic acid solution 106 to be sufficiently immersed in the conductor circuit 100X before the roughening treatment. On the other hand, the concentration of stearic acid solution 106 is 1.0 × 10 -2 A concentration of (mol / L) or less is preferable because it allows for smooth plasma treatment of the surface of the stearic acid-impregnated conductor circuit 100X.

[0032] Next, as shown in Figure 2G, the conductor circuit 100Y immersed in stearic acid is removed from the stearic acid solution 106. Then, as shown in Figure 2H, the conductor circuit 100Y removed from the stearic acid solution bath is washed with water. Furthermore, as shown in Figure 2I, the conductor circuit 100Y after washing is dried. That is, the conductor circuit 100X is immersed in the stearic acid solution 106 to form the conductor circuit 100Y, the conductor circuit 100Y is removed from the stearic acid solution bath, the removed conductor circuit 100Y is washed with water, and then dried. By going through the processing steps of the conductor circuit 100X of the printed circuit board 10 in this way, the conductor circuit 100X becomes a conductor circuit 100Y immersed in stearic acid. The conditions for washing and drying the conductor circuit 100Y are not particularly limited, as long as they can remove the unnecessary stearic acid, solvents contained in the stearic acid solution 106, etc. from the conductor circuit 100Y.

[0033] Next, as shown in Figure 2J, the conductor circuit 100Y obtained by impregnating it with stearic acid solution 106, washing it with water, and then drying it is plasma-treated with an oxygen-containing plasma. By plasma-treating the conductor circuit 100Y, the conductor circuit 100Y becomes conductor circuit 100Z. On the surface of the conductor circuit 100Z obtained by plasma-treating the conductor circuit 100Y, fine irregularities consisting of convex portions 110 and concave portions 111 are formed.

[0034] The surface of the conductor circuit 100Y contains stearic acid. Therefore, even if the surface of the conductor circuit 100Y is plasma-treated, the copper (Cu) contained in the electrolytic copper plating layer 105 that constitutes the conductor circuit 100Y is not removed. As a result, the width and thickness (height) of the conductor circuit 100Y are hardly reduced by the plasma treatment.

[0035] Furthermore, the conductive circuit 100Y is formed from an electrolytic copper plating layer 105 impregnated with stearic acid. Therefore, the copper (Cu) contained in the electrolytic copper plating layer 105 constituting the conductive circuit 100Y is transformed into copper oxide (Cu2O) on the conductive circuit surface of the conductive circuit 100Z by plasma treatment. The plasma treatment can be any treatment that can convert the copper (Cu) contained in the electrolytic copper plating layer 105 constituting the conductive circuit Y into copper oxide (Cu2O), and is preferably an oxygen-containing plasma such as atmospheric plasma or oxygen plasma.

[0036] Here, Figure 2K is a schematic diagram showing the microstructure of the surface of the conductor circuit 100Z in region R0. As shown in Figure 2K, the surface of the conductor circuit 100Z has multiple fine irregularities consisting of protrusions 110Z and recesses 111Z. That is, the surface of the conductor circuit 100Z has fine irregularities and is sufficiently roughened. The distance from the lower surface 112Z of the recess 111Z to the upper surface 113Z of the protrusion 110Z corresponds to the height H0 of the protrusion 110Z. The height H0 of the protrusion 110Z can be appropriately set depending on the stearic acid content, plasma treatment conditions, etc., but is preferably 1 to 50 nm, more preferably 5 to 30 nm.

[0037] Finally, as shown in Figure 2L, the fine irregularities formed on the surface of the conductor circuit 100Z are subjected to a reduction treatment. By reducing the fine irregularities formed on the surface of the conductor circuit 100Z, the copper oxide (Cu2O) constituting these irregularities can be reduced to copper (Cu). The reduction treatment is not particularly limited as long as it can reduce the copper oxide (Cu2O) constituting the irregularities to copper (Cu), and may include, for example, plasma treatment using water vapor plasma.

[0038] Alternatively, the reduction treatment may involve preparing a mixed solution of sodium borohydride and sodium hydroxide, immersing the fine irregularities formed on the surface of the conductor circuit 100Z in the mixture, followed by rinsing with water and drying.

[0039] In the method for manufacturing a printed circuit board according to the present invention, the protrusions 110 formed on the surface of the conductor circuit 100 of the printed circuit board 10 are made of copper (Cu) obtained by reducing copper oxide (Cu2O). Furthermore, the recesses 111 formed on the surface of the conductor circuit 100 of the printed circuit board 10 are made of copper (Cu) obtained by reducing copper oxide (Cu2O). Thus, the method for manufacturing a printed circuit board according to the present invention makes it possible to manufacture a printed circuit board 10 having a roughened shape with excellent adhesion to the insulating layer 101 by forming fine irregularities on the surface of the conductor circuit 100, which are composed of copper (Cu) obtained by reducing copper oxide (Cu2O). Furthermore, the method for manufacturing a printed circuit board according to the present invention makes it possible to provide a printed circuit board 10 having a conductor circuit surface that shows extremely little reduction in the amount of conductor circuitry even after roughening treatment of the conductor circuitry.

[0040] As described above, the method for manufacturing a printed circuit board according to the present invention involves forming a conductor circuit on an insulating layer, immersing the conductor circuit in a stearic acid solution, performing a water washing treatment and a drying treatment, and further performing a plasma treatment and a reduction treatment. As a result, the method for manufacturing a printed circuit board according to the present invention makes it possible to provide a printed circuit board having a conductor circuit with a roughened shape that has excellent adhesion to the insulating layer, by forming fine irregularities on the surface of the conductor circuit.

[0041] In other words, the method for manufacturing a printed circuit board according to the present invention involves a roughening treatment of a conductor circuit, By forming fine irregularities on the surface of the conductor circuit without etching the conductor circuit, it is possible to obtain a printed wiring board having a conductor circuit that has excellent adhesion to the insulating layer while minimizing the reduction in the thickness and height of the conductor circuit. Therefore, the method for manufacturing a printed circuit board according to the present invention can provide a printed circuit board having a conductor circuit based on a precise design of the conductor circuit, without considering the reduction in the width and thickness of the conductor circuit due to the roughening treatment of the conductor circuit surface, relative to the pre-set design values ​​of the conductor circuit. [Explanation of Symbols]

[0042] 10 Printed circuit boards 100 Conductor Circuits 100X Conductor Circuit (Before Roughening Treatment) 100Y Conductor Circuit (Stearic Acid Treatment and Drying) 100Z Conductor Circuit (After Plasma Treatment) 101 Insulating layer 110 Convex part 111 recess 112 Lower surface of the recess 113 Upper surface of the protrusion 110Z protrusion 111Z recess Lower surface of the 112Z recess 113Z Upper surface of the protrusion 101 Insulating layer 102 Seed Layer 103 Plating Resist 104 Recess for forming a conductor circuit 105 Electrolytic copper plating layer 106 Stearic acid solution 20 Printed circuit boards 200 Conductor Circuit

Claims

1. A method for manufacturing a printed wiring board having a conductor circuit surface in which the surface of the conductor circuit is roughened by forming fine irregularities on the surface of the conductor circuit, Forming a conductive circuit on an insulating layer, The aforementioned conductor circuit is immersed in a stearic acid solution, The process of removing the conductive circuit from the stearic acid solution, The conductive circuit removed from the stearic acid solution is washed with water, The conductor circuit after washing with water is dried, The aforementioned conductor circuit after drying is subjected to plasma treatment with an oxygen-containing plasma, A method for manufacturing a printed wiring board, comprising reducing the conductor circuit after the plasma treatment.

2. The concentration of the stearic acid solution is 1.0 × 10 －５ ~1.0 x 10 －２ A method for manufacturing a printed circuit board according to claim 1, wherein the ratio is (mol / L).

3. The method for manufacturing a printed circuit board according to claim 1, wherein the height of the uneven portion is 5 to 30 nm.

Images