JP2022012256A - Method for manufacturing wiring board - Google Patents

Abstract

To provide a method for manufacturing a wiring board capable of stably forming a wiring layer of a desired shape using a solid electrolyte membrane.SOLUTION: A method for manufacturing a wiring board comprises the steps of: preparing a base material with a seed layer, the base material with the seed layer including an insulating base material, a conductive ground layer provided on the insulating base material, and a conductive seed layer provided on a first region including a prescribed pattern corresponding to a wiring pattern on a surface of the ground layer; applying a solution containing at least one kind of an additive agent selected from a group consisting of a polymer, a brightener, and a leveler to the base material with the seed layer; arranging a solid electrolyte membrane containing a solution including metal ions between the seed layer and an anode, and forming a metal layer on a surface of the seed layer by applying voltage between the anode and the seed layer while pressure-welding the solid electrolyte membrane and the seed layer; and etching the ground layer.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a wiring board.

Conventionally, in the manufacture of wiring boards, a plating method has been widely used for forming wiring. However, the plating method requires washing with water after the plating treatment, and it is necessary to treat the waste liquid. Therefore, in Patent Document 1, a solid electrolyte membrane is placed between the anode and the cathode (base material), a solution containing metal ions is placed between the anode and the solid electrolyte membrane, and the solid electrolyte membrane is brought into contact with the base material. , A method of forming a metal film by applying a voltage between an anode and a base material to deposit a metal on the surface of the base material is described.

Japanese Unexamined Patent Publication No. 2014-185371

When wiring is formed by a normal plating method, various additives are generally added to the plating solution for the purpose of stabilizing the shape of the wiring. However, in the film forming method using the solid electrolyte membrane as described in Patent Document 1, the present inventors pass the additive through the solid electrolyte membrane even if the additive is added to the solution containing the metal ions. It has been found that the additive does not function and the wiring layer having a desired shape cannot be stably formed.

Therefore, the present invention provides a method for manufacturing a wiring substrate, which can stably form a wiring layer having a desired shape by using a solid electrolyte membrane.

According to one aspect of the present invention, there is a method for manufacturing a wiring board including an insulating base material and a wiring layer having a predetermined wiring pattern provided on the insulating base material.
(A) A step of preparing a base material with a seed layer.
Here, the base material with the seed layer is
With the insulating base material,
A conductive base layer provided on the insulating base material and
A step comprising a conductive seed layer provided on a first region of the surface of the substrate layer having a predetermined pattern corresponding to the wiring pattern.
(B) A step of applying a solution containing at least one additive selected from the group consisting of a polymer, a brightener, and a leveler to the substrate with a seed layer.
(C) A step of forming a metal layer on the surface of the seed layer.
Here, a solid electrolyte membrane containing a solution containing metal ions is placed between the seed layer and the anode, and the anode and the seed layer are brought into contact with each other while the solid electrolyte membrane and the seed layer are pressed against each other. Applying a voltage between the steps and
(D) The step of etching the base layer and
Are provided in this order.

In the production method of the present invention, the solid electrolyte membrane can be used to stably form a wiring layer having a desired shape.

FIG. 1 is a flowchart showing a method of manufacturing a wiring board according to an embodiment. FIG. 2 is a conceptual diagram illustrating a step of preparing a substrate with a seed layer. FIG. 3 is a conceptual diagram illustrating a step of preparing a substrate with a seed layer. FIG. 4 is a conceptual diagram illustrating a step of applying a solution containing an additive. FIG. 5 is a conceptual diagram illustrating a step of forming a metal layer. FIG. 6 is a conceptual diagram illustrating a step of etching the base layer. FIG. 7 is a schematic cross-sectional view showing a film forming apparatus used in the step of forming a metal layer. FIG. 8 is a schematic cross-sectional view showing the film forming apparatus shown in FIG. 7 in which the housing is lowered to a predetermined height. FIG. 9 is an SEM image of the wiring board of the first embodiment. FIG. 10 is an SEM image of the wiring board of the second embodiment. FIG. 11 is an SEM image of the wiring board of the third embodiment. FIG. 12 is an SEM image of the wiring board of the comparative example.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings referred to in the following description, the same member or a member having the same function may be designated by the same reference numeral, and the repeated description may be omitted. In addition, the dimensional ratio of the drawing may differ from the actual ratio for convenience of explanation, or a part of the member may be omitted from the drawing. Further, in the present application, the numerical range represented by using the symbol "-" includes the numerical values before and after the symbol "-" as the lower limit value and the upper limit value, respectively.

As shown in FIG. 1, the method for manufacturing a wiring board of an embodiment includes a step of preparing a base material with a seed layer (S1), a step of applying a solution containing an additive (S2), and forming a metal layer. It includes a step (S3) and a step (S4) of etching the base layer. Hereinafter, each step will be described.

(1) Step of preparing a base material with a seed layer (S1)
First, as shown in FIG. 2, the base layer 12 is formed on the main surface 11a of the insulating base material 11. As the insulating base material 11, for example, a base material containing a resin such as a glass epoxy resin base material and glass, a base material made of resin, a base material made of glass, or the like can be used. Examples of the resin used for the insulating base material 11 include epoxy resin, ABS resin, AS resin, AAS resin, PS resin, EVA resin, PMMA resin, PBT resin, PET resin, PPS resin, PA resin, POM resin, and PC. Resins, PP resins, PE resins, PI (polykimide) resins, polymer alloy resins containing elastomers and PP, thermoplastic resins such as modified PPO resins, PTFE resins, and ETFE resins, phenol resins, melamine resins, amino resins, unsaturated polyesters. Examples thereof include thermosetting resins such as resins, polyurethanes, diallyl phthalates, silicone resins and alkyd resins, resins obtained by adding cyanate resin to epoxy resins, and liquid crystal polymers.

The main surface 11a of the insulating base material 11 may be a flat surface. The average roughness Ra of the center line of the main surface 11a is not particularly limited, but may be 1 μm or less. As a result, the average roughness Ra of the center line of the surface 12a of the base layer 12 formed on the main surface 11a also becomes small, and a dispersion liquid of metal particles is applied as described later to form a seed layer 13 having a predetermined pattern. In this case, it is possible to prevent the pattern of the seed layer 13 from being deformed along the unevenness of the surface of the base layer. Therefore, the seed layer 13 having a fine pattern can be easily formed. The average roughness Ra of the center line is measured according to JIS B 0601: 1994.

The base layer 12 has sufficient conductivity for forming the metal layer 14 described later. Further, in the material of the base layer 12, the rising potential of the polarization curve of the base layer 12 is higher than the rising potential of the polarization curve of the seed layer 13, which will be described later, in the metal solution L used in the step (S3) of forming the metal layer. Choose to be high. In particular, the rising potential of the polarization curve of the base layer 12 may be 0.02 V or more higher than the rising potential of the polarization curve of the seed layer 13. The method for measuring the polarization curve will be described later. As an example of the material of the base layer 12, metal silicides such as FeSi ₂ , CoSi ₂ , MoSi ₂ , WSi ₂ , VSi ₂ , ReSi _1.75 , CrSi ₂ , NbSi ₂ , TaSi ₂ , TiSi ₂ , ZrSi ₂ and the like. ), Especially transition metal silicides, conductive metal oxides such as TiO ₂ , SnO, GeO, ITO (indium tin oxide), Ti, Al, or Cr, or alloys containing at least one of them, conductive resins. Can be mentioned. Further, the base layer 12 may have a natural oxide film on the surface. In the present application, the natural oxide film refers to an oxide film naturally formed on the surface of a substance when the substance is left in the atmosphere. Examples of natural oxide films include passivation films formed on the surface of an alloy containing Ti, Al, Cr, or at least one of them, and SiO ₂ formed on the surface of silicide. The base layer 12 may have a thickness of 20 nm or more, preferably 100 μm or more, from the viewpoint of in-plane uniformity of the metal layer 14 described later, and may have a thickness of 300 nm or less from the viewpoint of manufacturing cost.

The base layer 12 may be formed on the entire main surface 11a of the insulating base material 11. The base layer 12 may be formed by any method. For example, the base layer 12 can be formed by a PVD (physical vapor deposition) method such as a sputtering method, a CVD (chemical vapor deposition) method, or an electroless plating method. When the base layer 12 is formed by the sputtering method, the base layer 12 and the insulating base material 11 are firmly adhered to each other.

Next, as shown in FIG. 3, the seed layer 13 is formed on the first region R1 of the surface 12a of the base layer 12. The first region R1 is a region having a predetermined pattern corresponding to the wiring pattern of the wiring board manufactured by the manufacturing method of the embodiment. The seed layer 13 is electrically connected to the base layer 12.

The material of the seed layer 13 is such that the rising potential of the polarization curve of the seed layer 13 is lower than the rising potential of the polarization curve of the underlying layer 12 in the metal solution L used in the step (S3) of forming the metal layer. select. The method for measuring the polarization curve will be described later. The material of the seed layer 13 may be a conductive material that is not a conductive oxide and whose surface is difficult to spontaneously oxidize. For example, the material of the seed layer 13 may be a noble metal having high oxidation resistance. For example, the seed layer 13 may be formed from one or more metals selected from the group consisting of Pt, Pd, Rh, Cu, Ag, and Au. The seed layer 13 may have a thickness of 20 nm or more, preferably 1000 μm or more from the viewpoint of in-plane uniformity of the metal layer 14 described later, and has a thickness of 1 μm or less, preferably 300 nm or less from the viewpoint of manufacturing cost. It's okay. The line width and line spacing of the seed layer 13 are not particularly limited, but may be, for example, 2 μm or more and 100 μm or less.

The seed layer 13 may be formed by any method. For example, the seed layer 13 can be formed by applying a dispersion liquid of metal particles to the first region R1 and solidifying the dispersion liquid. The metal particles may contain one or more of the metals selected from the group consisting of Pt, Pd, Rh, Cu, Ag and Au. In order to form fine wiring, the metal particles preferably have a smaller particle size, and may have, for example, a particle size of 1 nm or more and 100 nm or less. Further, the metal particles may have a particle size of 20 nm or less. As a result, the melting point of the metal particles is lowered, so that the metal particles can be easily sintered. As the dispersion medium of the dispersion liquid, a liquid that volatilizes by heating, for example, decanol can be used. The dispersion may contain additives. Examples of additives include linear fatty acid salts having 10 to 17 carbon atoms. Examples of the method for applying the dispersion liquid include printing methods such as screen printing, inkjet printing, and transfer printing. The method for solidifying the dispersion is not particularly limited. For example, the dispersion liquid can be solidified by volatilizing the dispersion medium by heating and sintering the metal particles.

The seed layer 13 may be formed in the first region R1 by arranging a metal mask on the base layer 12 and performing vacuum vapor deposition, sputtering, or the like.

The surface 12a of the base layer 12 is exposed without being covered with the seed layer 13 in the second region R2, which is a region other than the first region R1. The underlayer 12 may contain oxides at least in the second region R2. For example, the entire base layer 12 may be composed of an oxide, the base layer 12 may have an oxide film on the entire surface 12a, or the base layer 12 may have an oxide film on the second region R2 of the surface 12a. May have. The oxide film may be a natural oxide film or a film formed by any film forming method.

The first region R1 may consist of only one continuous region, or may include a plurality of independent regions. When the first region R1 includes a plurality of independent regions, the seed layer 13 formed in each independent region is electrically connected via the base layer 12. Therefore, it is not necessary to provide the lead wiring for use in the step (S3) of forming the metal layer, which will be described later, for each of the seed layers 13 formed in each independent region.

In this way, the insulating base material 11, the conductive base layer 12 provided on the insulating base material 11, and the conductive seed layer provided on the first region R1 of the surface 12a of the base layer 12. 13 and a substrate 10 with a seed layer are obtained. The base material 10 with a seed layer does not have to be prepared by itself, and a prefabricated base material 10 may be purchased.

(2) Step of applying a solution containing an additive (S2)
Prepare a solution containing at least one additive selected from the group consisting of polymers, Brighteners, and levelers. The solution is mixed by adding an additive to a solution containing metal ions (hereinafter referred to as a metal solution) which is a material of the metal layer 14 (see FIG. 5) used in the subsequent step (S3) of forming the metal layer. Can be prepared by

As at least one additive selected from the group consisting of a polymer, a brightener, and a leveler, an additive used as a polymer, a brightener, and a leveler in ordinary electrolytic plating is used as a material for the metal layer 14 (see FIG. 5). It may be appropriately selected and used according to the above.

As the polymer, for example, a nonionic polyether polymer surfactant such as polyethylene glycol, polypropylene glycol, polyethylene oxide, or polyoxyalkylene glycol can be used. The polymer is a component that forms a monomolecular film at the interface between the cathode and the electrolytic solution (plating solution) in electrolytic plating and has an effect of suppressing metal precipitation.

Brighteners include, for example, sulfur-containing organic compounds, more specifically 3-mercaptopropanesulfonic acid, sodium salts thereof, bis (3-sulfopropyl) disulfides, disodium salts thereof, N, N-dimethyldithiocarbamic acid. An organic sulfur-based compound having a sulfonic acid group such as (3-sulfopropyl) ester and a sodium salt thereof can be used. Brightener is a component having an effect of promoting metal precipitation in electrolytic plating, refining the deposited metal particles, and giving luster to the formed metal layer.

As the leveler, for example, a nitrogen-containing organic compound such as Janus Green B (JGB), a quaternary ammonium compound such as a safranin compound, a phenazine compound, a polyalkyleneimine, thiourea and its derivative, and a polyacrylic acid amide should be used. Can be done. The leveler is a component having an effect of adsorbing a large amount of metal to the convex portion where metal is likely to precipitate in electrolytic plating, suppressing the precipitation of metal in the convex portion, and improving the flatness of the formed metal layer.

The prepared solution containing the additive is applied to the base material 10 with a seed layer to form a solution layer 16 on the base material 10 with a seed layer as shown in FIG. The coating method is not particularly limited, and any method such as a drop cast method or a dip method may be used.

(3) Step of forming a metal layer (S3)
As shown in FIG. 5, a metal layer 14 is formed on the surface of the seed layer 13. Examples of the material of the metal layer 14 include Cu, Ni, Ag, Au and the like, and Cu may be preferable. The metal layer 14 may have a thickness of, for example, 1 μm or more and 100 μm or less.

7 and 8 show an example of the film forming apparatus 50 used for forming the metal layer 14. The film forming apparatus 50 includes a metal anode 51 arranged so as to face the seed layer 13, a solid electrolyte film 52 arranged between the anode 51 and the seed layer 13, and the anode 51 and the seed layer 13. A power supply unit 54 for applying a voltage is provided between the two.

The film forming apparatus 50 further includes a housing 53. The housing 53 houses the anode 51 and the metal solution L. As shown in FIG. 7, the housing 53 may define a space in which the metal solution L is accommodated between the anode 51 and the solid electrolyte membrane 52. In this case, the anode 51 is formed of a plate-like member which is the same as the material of the metal layer 14 and is soluble in the metal solution L (for example, Cu), or is formed of a material insoluble in the metal solution L (for example, Ti). It can be a plate-shaped member. In the film forming apparatus 50 in which the metal solution L is accommodated between the anode 51 and the solid electrolyte film 52, the solid electrolyte film 52 and the base material 10 with the seed layer can be pressed together at a uniform pressure, so that the seed layer can be pressed. It is possible to uniformly form the metal layer 14 on the seed layer 13 over the entire surface of the attached base material 10. Therefore, such a film forming apparatus 50 is suitable for forming a fine wiring pattern.

Although not shown in the figure, the anode 51 and the solid electrolyte membrane 52 may be in contact with each other. In this case, the anode 51 may be formed of a porous body capable of permeating the metal solution L, and the surface opposite to the surface of the anode 51 in contact with the solid electrolyte film 52 is a space in which the metal solution L is accommodated. May be in contact with.

Examples of the material of the solid electrolyte membrane 52 include a fluorine-based resin such as Nafion (registered trademark) manufactured by DuPont, a hydrocarbon-based resin, a polyamic acid resin, and a cation (CMV, CMD, CMF series) manufactured by Asahi Glass Co., Ltd. Examples thereof include a resin having an ion exchange function. When the solid electrolyte membrane 52 is brought into contact with the metal solution L, the metal solution L permeates the solid electrolyte membrane 52. As a result, the solid electrolyte membrane 52 contains the metal solution L inside. The solid electrolyte membrane 52 may have a thickness of, for example, about 5 μm to about 200 μm.

The metal solution L contains a metal (for example, Cu, Ni, Ag, Au, etc.) which is a material of the metal layer 14 in an ionic state. The metal solution L may contain nitrate ion, phosphate ion, succinate ion, sulfate ion, and pyrophosphate ion. The metal solution L may be a solution of a metal salt, for example, a nitrate, a phosphate, a succinate, a sulfate, a pyrophosphate or the like.

Further, the film forming apparatus 50 includes an elevating device 55 for raising and lowering the housing 53 above the housing 53. The elevating device 55 may include, for example, a hydraulic or pneumatic cylinder, an electric actuator, a linear guide, a motor, and the like.

The housing 53 has a supply port 53a and a discharge port 53b. The supply port 53a and the discharge port 53b are connected to the tank 61 via the pipe 64. The metal solution L sent out from the tank 61 by the pump 62 connected to the pipe 64 flows into the housing 53 from the supply port 53a, is discharged from the housing 53 through the discharge port 53b, and returns to the tank 61. The pipe 64 is provided with a pressure regulating valve 63 downstream of the discharge port 53b. The pressure of the metal solution L in the housing 53 can be adjusted by the pressure adjusting valve 63 and the pump 62.

The film forming apparatus 50 further electrically connects the metal pedestal 56 on which the base material 10 with the seed layer is placed to the base layer 12 or the seed layer 13 of the base material 10 with the seed layer and the metal pedestal 56. The conductive member 57 of the above is provided. The conductive member 57 may be a metal plate that covers a part of the edge of the base material 10 with a seed layer and is partially bent to come into contact with the metal pedestal 56. As a result, the metal pedestal 56 is electrically connected to the base layer 12 and the seed layer 13 via the conductive member 57. The conductive member 57 may be removable from the base material 10 with a seed layer.

The negative electrode of the power supply unit 54 is electrically connected to the base layer 12 and the seed layer 13 via the metal pedestal 56, and the positive electrode of the power supply unit 54 is electrically connected to the anode 51.

The metal layer 14 can be formed by using the film forming apparatus 50 as follows.

As shown in FIG. 7, the base material 10 with a seed layer and the conductive member 57 on which the solution layer 16 is formed are placed at predetermined positions on the metal pedestal 56. Then, as shown in FIG. 8, the housing 53 is lowered to a predetermined height by the elevating device 55.

Next, the metal solution L is pressurized by the pump 62. Then, the pressure adjusting valve 63 keeps the metal solution L in the housing 53 at a predetermined pressure. Further, the solid electrolyte membrane 52 comes into contact with the surface of the seed layer 13. As a result, the metal solution L contained in the solid electrolyte membrane 52 comes into contact with the surface of the seed layer 13. The solid electrolyte membrane 52 is uniformly pressed against the surface of the seed layer 13 by the pressure of the metal solution L in the housing 53. The solution layer 16 is sandwiched between the second region R2 (see FIG. 4 and the like) of the surface 12a of the base layer 12 and the solid electrolyte membrane 52.

A voltage is applied between the anode 51 and the seed layer 13 by the power supply unit 54. As described above, the rising potential of the polarization curve of the base layer 12 in the metal solution L is higher than the rising potential of the polarization curve of the seed layer 13 in the metal solution L. This is because the activation energy of the reduction reaction of the metal ion contained in the metal solution L on the surface 12a of the base layer 12 is the activation energy of the reduction reaction of the metal ion contained in the metal solution L on the surface of the seed layer 13. Means higher than. Therefore, when a voltage is applied between the anode 51 and the seed layer 13, the metal ions contained in the metal solution L in contact with the seed layer 13 are selectively reduced on the surface of the seed layer 13 to the surface of the seed layer 13. Metal precipitates. As a result, the metal layer 14 is selectively formed on the surface of the seed layer 13. The metal layer 14 may be formed not only on the upper surface but also on the side surface of the seed layer 13, whereby the adhesion between the metal layer 14 and the seed layer 13 can be improved.

The voltage applied between the anode 51 and the seed layer 13 is equal to or higher than the rising potential of the polarization curve of the seed layer 13 in the metal solution L and equal to or lower than the rising potential of the polarization curve of the underlying layer 12 in the metal solution L. May be. In this case, a current flows between the seed layer 13 and the anode 51, but substantially no current flows between the base layer 12 and the anode 51. Therefore, the metal is more selectively deposited on the surface of the seed layer 13.

Further, due to the action of the additive contained in the solution layer 16, the growth of the formed metal layer 14 in the lateral direction (direction parallel to the main surface 11a of the insulating base material 11) is suppressed, and the pattern of the seed layer 13 is suppressed. The metal layer 14 having the pattern corresponding to the above can be stably formed.

For example, when the solution layer 16 contains a polymer as an additive, the polymer forms a monomolecular film on the side surface of the seed layer 13 and the side surface of the formed metal layer 14, and the metal on the side surface of the seed layer 13 and the metal layer 14. Suppresses precipitation. As a result, the lateral growth of the metal layer 14 is suppressed.

When the solution layer 16 contains a brightener as an additive, the brightener promotes the precipitation of metal on the upper surfaces of the seed layer 13 and the metal layer 14 where the metal is likely to precipitate, and the metal on the side surfaces of the seed layer 13 and the metal layer 14. Precipitation is relatively suppressed. As a result, the lateral growth of the metal layer 14 is suppressed.

When the solution layer 16 contains a leveler as an additive, the leveler is adsorbed on the side surface of the seed layer 13 and the side surface of the formed metal layer 14, and suppresses the precipitation of metal on the side surface of the seed layer 13 and the metal layer 14. In particular, when there are convex portions on the side surfaces of the seed layer 13 and the metal layer 14, many levelers are adsorbed on the convex portions to suppress the precipitation of metal in the convex portions. As a result, the side surface of the metal layer 14 is flattened. Therefore, the lateral growth of the metal layer 14 is suppressed.

After the metal layer 14 having a predetermined thickness is formed, the application of the voltage between the anode 51 and the seed layer 13 is stopped, and the pressurization of the metal solution L by the pump 62 is stopped. Then, the housing 53 is raised to a predetermined height (see FIG. 9), and the base material 10 with a seed layer on which the metal layer 14 is formed is removed from the metal pedestal 56. Next, the solution layer 16 on the base material 10 with a seed layer is removed by washing with water, drying, or the like.

The polarization curves of the base layer 12 and the seed layer 13 in the metal solution L described above are measured using a potentiostat (HZ-7000 manufactured by Hokuto Denko Co., Ltd.) under the following conditions.
Working electrode: Electrode made of the same material as the material constituting the base layer 12 or the seed layer 13 Counter electrode: Anode 51 used in step (S3)
Reference electrode: Saturated calomel electrode (HC-205C manufactured by DKK-TOA CORPORATION)
Electrolyte: Metal solution L used in step (S3)
Electrolyte temperature: 25 ° C
Potential sweep speed: 10 mV / sec

In the present application, the potential when the current density is 0.1 mA / cm ² in the polarization curve is defined as the rising potential.

(4) Step of etching the base layer (S4)
Then, as shown in FIG. 6, the base layer 12 (see FIG. 5) is etched. In the etching of the base layer 12, since the metal layer 14 serves as a mask, the portion 12b of the base layer 12 located below the metal layer 14 (hereinafter, referred to as “appropriately, residual base layer”) 12b is not etched. It remains on the insulating substrate 11. As a result, the wiring layer 2 having a predetermined wiring pattern including the residual base layer 12b, the seed layer 13 and the metal layer 14 is formed on the insulating base material 11.

The etching gas or etching solution used for etching the base layer 12 may be appropriately selected depending on the material of the base layer 12. Examples of the etching gas include CF ₄ , SF ₆ , boron, chlorine, HBr, and BCl ₃ . Further, as the etching solution, an acid or alkaline solution such as HF can be used. For example, when the base layer 12 is formed of silicide, the base layer ₁₂ can be etched by a reactive ion etching method using CF4 gas.

As described above, the wiring board 1 including the insulating base material 11 and the wiring layer 2 having a predetermined wiring pattern provided on the insulating base material 11 is manufactured. The manufacturing method according to the embodiment includes a step (S2) of applying a solution containing an additive to form a metal layer in the lateral direction of the metal layer 14 (mainly the insulating base material 11). Since the growth in the direction parallel to the surface 11a is suppressed, the wiring layer 2 having a desired shape can be stably formed.

In the manufacturing method according to the embodiment, since the wiring board 1 can be manufactured without using a resist mask, it is possible to reduce the manufacturing cost and the manufacturing time of the wiring board 1.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes are made without departing from the spirit of the present invention described in the claims. It can be performed.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

Example 1
A glass base material was prepared as an insulating base material. A Ti layer was formed as a base layer on the surface of the insulating base material by a sputtering method. Next, using an ink containing silver nanoparticles, an Ag layer having a predetermined pattern was formed as a seed layer on the surface of the base layer by a screen printing method. As a result, a substrate with a seed layer was obtained.

Three drops of "Top Lucina SF Base" manufactured by Okuno Pharmaceutical Industry Co., Ltd. were added to 3 mL of a 1 mol / L copper sulfate aqueous solution and mixed to prepare a solution containing a polymer. Five drops of the prepared solution were dropped on the surface of the substrate with a seed layer and spread to form a solution layer on the surface of the substrate with a seed layer.

Using the film forming apparatus 50 shown in FIGS. 9 and 10, a Cu layer having a thickness of 4 μm was formed as a metal layer on the surface of the seed layer under the following conditions.
Cathode: Seed layer Anode: Oxygen-free copper plate (C1020)
Solid electrolyte membrane: Nafion (registered trademark) (thickness approx. 8 μm)
Metal solution: 1.0 mol / L copper sulfate aqueous solution Pressure to press the solid electrolyte film against the seed layer: 1.0 MPa
Current density: 92mA / cm ²

Next, using the metal layer as a mask, the base layer was etched by vacuum plasma etching using _CF4 gas until the surface of the insulating base material was exposed. As a result, a wiring layer having a predetermined wiring pattern composed of a residual base layer, a seed layer, and a metal layer was formed on the insulating base material. In this way, a wiring board including an insulating base material and a wiring layer was obtained.

Example 2
Same as in Example 1 except that 3 drops of "Top Lucina SF-B" manufactured by In The Back Pharmaceutical Industry Co., Ltd. was added to 3 mL of a 1 mol / L copper sulfate aqueous solution and mixed to prepare a solution containing Brightener. A wiring board was produced.

Example 3
Wiring was performed in the same manner as in Example 1 except that a solution containing the leveler was prepared by adding 3 drops of "Top Lutina SF Leveler" manufactured by Okuno Pharmaceutical Industry Co., Ltd. to 3 mL of a 1 mol / L copper sulfate aqueous solution and mixing them. A substrate was prepared.

Comparative Example A wiring board was produced in the same manner as in Example 1 except that a solution layer was not formed on the surface of the substrate with a seed layer.

Evaluation The wiring boards of Examples 1 to 3 and Comparative Examples were observed with a scanning electron microscope (SEM). SEM images are shown in FIGS. 9-12. As shown in FIG. 12, in the wiring board of the comparative example, the metal layer grew in the lateral direction (direction parallel to the main surface of the insulating base material), and the distance between the wirings became small. As shown in FIGS. 9 to 11, in the wiring boards of Examples 1 to 3, the lateral growth of the metal layer was suppressed, and the distance between the wirings was sufficiently maintained.

1: Wiring board 2: Wiring layer, 10: Base material with seed layer, 11: Insulating base material, 12: Base layer, R1: First region, R2: Second region, 13: Seed layer, 14 : Metal layer, 16: Solution layer, 50: Film forming equipment

Claims (1)

A method for manufacturing a wiring board comprising an insulating base material and a wiring layer having a predetermined wiring pattern provided on the insulating base material.
(A) A step of preparing a base material with a seed layer.
Here, the base material with the seed layer is
With the insulating base material,
A conductive base layer provided on the insulating base material and
A step comprising a conductive seed layer provided on a first region of the surface of the substrate layer having a predetermined pattern corresponding to the wiring pattern.
(B) A step of applying a solution containing at least one additive selected from the group consisting of a polymer, a brightener, and a leveler to the substrate with a seed layer.
(C) A step of forming a metal layer on the surface of the seed layer.
Here, a solid electrolyte membrane containing a solution containing metal ions is placed between the seed layer and the anode, and the anode and the seed layer are brought into contact with each other while the solid electrolyte membrane and the seed layer are pressed against each other. Applying a voltage between the steps and
(D) The step of etching the base layer and
In this order, the method.

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