Deposition apparatus for metallic film

Abstract

To make it possible to accurately deposit a metallic film with a predetermined pattern using a masking material with a masking portion made of a rubber material.SOLUTION: A masking material 60 for a deposition apparatus 1 has a perforation 68 formed, and has a masking portion 65 made of a rubber material. On the opposite surface 65c facing a polymer electrolyte 13 among the surfaces of the masking portion 65, a contact prevention material 30 (coating sheet 30A) made of a resin material is arranged for preventing the masking portion 65 from contacting the polymer electrolyte 13.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a metal film forming apparatus. [Background technology]

[0002] Conventionally, a metal coating has been formed by precipitating a metal on the surface of a substrate by electrolytic plating (for example, Patent Document 1). The film forming apparatus disclosed in Patent Document 1 includes a container (housing) that contains a plating solution. An opening is formed in the container, and the opening is sealed with an electrolyte membrane. The film forming apparatus further includes a pressing mechanism that presses the electrolyte membrane against the substrate by the hydraulic pressure of the plating solution.

[0003] Here, when forming a metal coating on the surface of the substrate, a voltage is applied between the anode and the substrate while pressing the substrate with the liquid pressure of the electrolyte membrane. This allows a metal coating of a predetermined pattern to be formed on the underlayer. When forming a metal coating of a predetermined pattern on the substrate, it is also assumed that a masking material shown in Patent Document 2 may be used. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-125087 A [Patent Document 2] JP 2016-108586 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the masking portion of the masking material shown in Patent Document 2 is made of a rubber material, when the masking material is pressed by the electrolyte membrane during film formation, rubber particles (rubber powder) from the masking portion adhere to the surface of the electrolyte membrane. When the electrolyte membrane stretches slightly due to the hydraulic pressure of the plating solution, it covers a part of the through-hole formed in the masking portion. As a result, during film formation, the movement of metal ions from the through-hole toward the substrate is hindered by the rubber particles adhering to the electrolyte membrane. This makes it difficult to form a metal coating in a predetermined pattern according to the shape of the through-hole.

[0006] The present invention has been made in consideration of these points, and its object is to provide a metal coating deposition device that can precisely deposit a metal coating in a predetermined pattern using a masking material having a mask portion made of a rubber material. [Means for solving the problem]

[0007] In view of the above-mentioned problems, a metal film forming apparatus according to the present invention is an apparatus for forming a metal film of a predetermined pattern on a surface of a substrate by electrolytic plating, the metal film forming apparatus comprising: a container having an opening formed at a position facing the substrate, the opening being covered with an electrolyte membrane while a plating solution is contained therein; a pressing mechanism for pressing the substrate with the electrolyte membrane by hydraulic pressure of the plating solution contained in the container; an anode disposed inside the container at a position facing the electrolyte membrane; and a masking material disposed between the electrolyte membrane and the substrate, the masking material having a through portion of the predetermined pattern formed therein, the masking material having a mask portion formed with the through portion and made of a rubber material, and a contact prevention material made of a resin material that prevents contact between the mask portion and the electrolyte membrane is disposed on a surface of the mask portion that faces the electrolyte membrane.

[0008] According to the present invention, during the film formation, a masking material is brought into contact between the electrolyte membrane and the substrate, and the electrolyte membrane is pressed against the substrate via the masking material by the pressure of the plating solution contained in the container. When a voltage is applied between the anode and the substrate in this state, metal ions contained in the plating solution contained in the container pass through the electrolyte membrane, and moisture in the plating solution seeps out from the electrolyte membrane as an exudation liquid. As a result, the exudation liquid is filled in the through-hole formed in the mask portion with the elastically deformed mask portion in close contact with the surface of the substrate, and pressure is applied. In this state, the metal ions of the plating solution pass through the through-hole, and the passing metal ions become metal and precipitate on the surface of the substrate. As a result, a metal coating having a predetermined pattern according to the shape of the through-hole can be formed on the surface of the substrate.

[0009] Here, even if the electrolyte membrane is deformed toward the mask portion due to the hydraulic pressure of the plating solution, the electrolyte membrane can be prevented from contacting the opposing surface of the mask portion because the surface of the mask portion facing the electrolyte membrane is provided with a contact prevention material made of a resin material. This makes it possible to prevent rubber particles derived from the rubber material of the mask portion from adhering to the electrolyte membrane. As a result, even if the electrolyte membrane is deformed due to the hydraulic pressure of the plating solution, the movement of metal ions is not hindered by the rubber particles in the part of the electrolyte membrane covering the through-hole of the mask portion, so that a metal coating of a predetermined pattern can be formed with high accuracy.

[0010] In a more preferred embodiment, the contact prevention material is a covering sheet that is placed on the opposing surface so as to cover the through-hole, and the covering sheet has a plurality of openings formed therein that allow the plating solution to pass through, at least at positions that cover the through-hole.

[0011] According to this aspect, the covering sheet is disposed on the opposing surface so as to cover the through-portion, and therefore, the adhesion of rubber particles to the electrolyte membrane can be suppressed. In addition, the covering sheet is disposed so as to cover the through-portion of the mask portion, and therefore, the slackness of the electrolyte membrane, which is deformed by the hydraulic pressure of the plating solution, can be suppressed. Furthermore, the hydraulic pressure of the plating solution can be applied uniformly to the mask portion through the electrolyte membrane and the covering sheet. This allows the deformation of the mask portion to be uniform, and therefore the sealing property between the mask portion and the substrate can be stably secured. Furthermore, since a plurality of openings through which the plating solution passes are formed at least at the position covering the through-portion, the seepage liquid seeping out from the electrolyte membrane passes through the openings of the covering sheet and is supplied to the through-portion. As a result, during the film formation, metal ions move in the seepage liquid filled in the through-portion, and therefore, a metal film according to the pattern of the through-portion can be stably formed on the surface of the substrate.

[0012] In a more preferred embodiment, the mask portion has a first portion facing the electrolyte membrane and a second portion facing the substrate, and the masking material has a mesh portion woven with wire, the mesh portion being disposed between the first portion and the second portion and holding the first portion and the second portion.

[0013] According to this embodiment, the mesh portion is sandwiched between the first portion facing the electrolyte membrane and the second portion facing the substrate, so that the force acting on the mesh portion due to the liquid pressure of the plating solution can be uniformly distributed to the second portion. This allows the deformation of the second portion to be uniform, so that the sealing performance between the mask portion and the substrate can be stably ensured. Furthermore, since mesh openings of the mesh portion are formed at the positions of the penetration portions, the seeping liquid that seeps out from the electrolyte membrane passes through the mesh openings of the mesh portion. As a result, metal derived from metal ions can be stably precipitated on the surface of the substrate. Since the first and second portions can be continuously formed through the mesh openings of the mesh portion, the mask portion can be stably held on the mesh portion.

[0014] In a more preferred embodiment, the covering sheet is a sheet made of a mesh woven with wires, and the mesh openings of the covering sheet are larger than the mesh openings of the mesh portion.

[0015] According to this aspect, since the mesh openings of the covering sheet are larger than the mesh openings of the mesh portion, the seepage liquid exuded from the electrolyte membrane can be smoothly supplied to the through-holes of the mask portion through the openings of the covering sheet, thereby forming a metal coating with a stable pattern.

[0016] In another preferred embodiment, the contact-preventing material is a resin film that covers the opposing surface.

[0017] According to this embodiment, since the resin film covers the surface facing the mask portion, it is possible to prevent the rubber particles from adhering to the electrolyte membrane, and the seepage liquid (plating liquid) seeping out from the electrolyte membrane is smoothly supplied to the through-holes in the mask portion, thereby stably forming a metal film in a desired pattern. Effect of the Invention

[0018] According to the present invention, a metal film having a predetermined pattern can be formed with high accuracy by using a masking material having a mask portion made of a rubber material. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic cross-sectional view showing an example of a metal film forming apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic perspective view showing the covering sheet, the masking material, and the substrate on which the metal coating is formed, shown in FIG. [Diagram 3] 2 is a schematic cross-sectional view for explaining film formation by the film formation apparatus shown in FIG. 1. [Figure 4]4 is an enlarged cross-sectional view of a main part for explaining the formation of a metal film by the film forming apparatus shown in FIG. [Diagram 5] FIG. 4 is a schematic perspective view showing a modified example of the masking material shown in FIG. [Figure 6] 6 is an enlarged cross-sectional view of a main part for explaining the formation of a metal film using the film formation apparatus shown in FIG. 5. [Figure 7] FIG. 11 is an enlarged cross-sectional view for explaining the formation of a metal film using a masking material according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] A description will now be given of a metal coating deposition apparatus 1 according to an embodiment of the present invention. Fig. 1 is a schematic cross-sectional view showing an example of a metal coating deposition apparatus according to an embodiment of the present invention.

[0021] 1, the film formation apparatus 1 is a film formation apparatus that forms a metal coating F of a predetermined pattern P on a substrate B by electrolytic plating in a state in which a masking material 60 is sandwiched between an electrolyte membrane 13 and the substrate B. Specifically, the film formation apparatus 1 includes an anode 11, an electrolyte membrane 13, and a power source 14 that applies a voltage between the anode 11 and the substrate B.

[0022] The film forming apparatus 1 includes a container 15 that contains an anode 11 and a plating solution L, a mounting table 40 for mounting a substrate B thereon, and a masking material 60. During film formation, the masking material 60 is mounted on the mounting table 40 together with the substrate B. The electrolyte membrane 13 is disposed between the masking material 60 and the anode 11.

[0023] The film forming apparatus 1 includes a linear actuator 70 that raises and lowers the container 15. In this embodiment, for convenience of explanation, it is assumed that the electrolyte membrane 13 is disposed below the anode 11, and the masking material 60 and the substrate B are disposed further below that. However, as long as the metal film F can be formed on the surface of the substrate B, the positional relationship is not limited to this.

[0024] The substrate B functions as a cathode. The substrate B is a plate-shaped substrate. In this embodiment, the substrate B is a rectangular substrate. Of the surfaces of the substrate B, the surface facing the electrolyte membrane 13 (screen mask 62) is a film formation surface that functions as a cathode. The material of the substrate B is not particularly limited as long as it functions as a cathode (i.e., a surface having electrical conductivity). The substrate B may be made of a metal material such as aluminum or copper, for example.

[0025] 2, in this embodiment, a pattern (wiring pattern) P is formed from a metal coating F, so a base material having a base layer Bb of copper or the like formed on the surface of an insulating substrate Ba of resin or the like is used as the base material B. In this case, after the metal coating F is formed, the base layer Bb other than the portion on which the metal coating F is formed is removed by etching or the like. This allows the pattern P of the metal coating F to be formed on the surface of the insulating substrate Ba.

[0026] The anode 11 is, for example, a non-porous (e.g., non-porous) anode made of the same metal as the metal of the metal coating. The anode 11 has a block or plate shape. The material of the anode 11 can be, for example, copper. The anode 11 dissolves when a voltage is applied from the power source 14. However, when the film is formed using only the metal ions of the plating solution L, the anode 11 is an anode that is insoluble in the plating solution L. The anode 11 is electrically connected to the positive electrode of the power source 14. The negative electrode of the power source 14 is electrically connected to the substrate B via the mounting table 40.

[0027] The plating solution L is a solution containing the metal of the metal film to be formed in an ion state. Examples of the metal include copper, nickel, gold, silver, and iron. The plating solution L is a solution in which these metals are dissolved (ionized) with an acid such as nitric acid, phosphoric acid, succinic acid, sulfuric acid, or pyrophosphoric acid. Examples of the solvent of the solution include water and alcohol. For example, when the metal is copper, the plating solution L can be an aqueous solution containing copper sulfate, copper pyrophosphate, or the like.

[0028] The electrolyte membrane 13 is a membrane that can be impregnated (contained) with metal ions together with the plating solution L by contacting the electrolyte membrane 13 with the plating solution L. The electrolyte membrane 13 is a flexible membrane. The material of the electrolyte membrane 13 is not particularly limited as long as the metal ions of the plating solution L can migrate to the substrate B side when a voltage is applied from the power source 14. Examples of the material of the electrolyte membrane 13 include resins having an ion exchange function, such as fluororesins such as Nafion (registered trademark) manufactured by DuPont. The thickness of the electrolyte membrane 13 is preferably in the range of 20 μm to 200 μm. More preferably, the thickness is in the range of 20 μm to 60 μm.

[0029] The container 15 is made of a material insoluble in the plating solution L. The container 15 has a container space 15a for containing the plating solution L. The anode 11 is disposed in the container space 15a of the container 15. An opening 15d is formed on the side of the container space 15a facing the substrate B. The opening 15d of the container 15 is covered with the electrolyte membrane 13. Specifically, the periphery of the electrolyte membrane 13 is sandwiched between the container 15 and the frame 17. This allows the plating solution L in the container space 15a to be sealed by the electrolyte membrane 13.

[0030] 1 and 3, the linear actuator 70 raises and lowers the housing 15 so that the electrolyte membrane 13 and the masking material 60 can be brought into contact with and separated from each other. In this embodiment, the mounting table 40 is fixed, and the housing 15 is raised and lowered by the linear actuator 70. The linear actuator 70 is an electric actuator, and converts the rotational motion of a motor into linear motion by a ball screw or the like (not shown). However, instead of the electric actuator, a hydraulic or pneumatic actuator may be used.

[0031] The container 15 is formed with a supply flow path 15b for supplying the plating solution L to the container space 15a. Furthermore, the container 15 is formed with a discharge flow path 15c for discharging the plating solution L from the container space 15a. The supply flow path 15b and the discharge flow path 15c are holes communicating with the container space 15a. The supply flow path 15b and the discharge flow path 15c are formed on either side of the container space 15a. The supply flow path 15b is fluidly connected to a liquid supply pipe 51. The discharge flow path 15c is fluidly connected to a liquid discharge pipe 52.

[0032] The film forming apparatus 1 further includes a liquid tank 90, a liquid supply pipe 51, a liquid discharge pipe 52, and a pump 80. As shown in FIG. 1, the liquid tank 90 contains a plating liquid L. The liquid supply pipe 51 connects the liquid tank 90 and the accommodation body 15. The liquid supply pipe 51 is provided with a pump 80. The pump 80 supplies the plating liquid L from the liquid tank 90 to the accommodation body 15. The liquid discharge pipe 52 connects the liquid tank 90 and the accommodation body 15. The liquid discharge pipe 52 is provided with a pressure adjustment valve 54. The pressure adjustment valve 54 adjusts the pressure (liquid pressure) of the plating liquid L in the accommodation space 15a to a predetermined pressure.

[0033] In this embodiment, the plating solution L is sucked from the liquid tank 90 into the liquid supply pipe 51 by driving the pump 80. The sucked plating solution L is pressure-fed from the supply flow path 15b to the accommodation space 15a. The plating solution L in the accommodation space 15a is returned to the liquid tank 90 via the discharge flow path 15c. In this manner, the plating solution L circulates within the film forming apparatus 1.

[0034] Furthermore, by continuing to drive the pump 80, the liquid pressure of the plating solution L in the accommodation space 15a can be maintained at a predetermined pressure by the pressure regulating valve 54. The pump 80 presses the masking material 60 through the cover sheet 30A by the electrolyte membrane 13 acting on the liquid pressure of the plating solution L. However, the pressing mechanism is not particularly limited as long as it is capable of pressing the masking material 60 by the electrolyte membrane 13. Instead of the pump 80, an injection mechanism composed of a piston and a cylinder for injecting the plating solution L may be used.

[0035] The mounting table 40 is formed of a conductive material (such as a metal), for example. A recess 41 is formed in the mounting table 40. The recess 41 is a portion recessed from the opposing surface of the mounting table 40 in order to accommodate the substrate B.

[0036] The masking material 60 includes a frame 61 and a screen mask 62. The frame 61 supports a peripheral edge 62a of the screen mask 62 on the electrolyte membrane 13 side relative to the frame 61. Specifically, the peripheral edge 62a of the screen mask 62 is fixed to the frame 61. In this embodiment, the screen mask 62 has a rectangular outer shape. Therefore, the frame 61 has a rectangular frame-like shape. The material of the frame 61 is not particularly limited as long as it can maintain the shape of the masking material 60. For example, the material of the frame 61 can be a metal material such as stainless steel, or a resin material such as thermoplastic resin. The frame 61 is formed, for example, by punching a metal plate, and has a thickness of about 1 mm to 3 mm.

[0037] The screen mask 62 has through-holes 68 formed according to a predetermined pattern P of the metal coating F. The screen mask 62 includes a mesh portion 64 and a mask portion 65. The screen mask 62 is a mask having flexibility of about 50 μm to 400 μm. The screen mask 62 is supported by the surface of the frame 61 on the substrate B side.

[0038] The periphery of the mesh portion 64 is fixed to the frame body 61. The mesh portion 64 is stretched with a predetermined tension so as to cover the opening of the frame body 61. The mesh portion 64 has a plurality of openings 64c, 64c, ... formed in a lattice shape. Specifically, as shown in FIG. 4, the mesh portion 64 is made of a mesh-like portion (mesh) in which a plurality of oriented wire materials 64a, 64b are woven so as to cross each other. The plurality of wire materials 64a, 64a are arranged at intervals, and the plurality of wire materials 64b, 64b that cross these are arranged at intervals. As a result, a plurality of openings 64c, 64c, ... are formed in the mesh portion 64 in a lattice shape. The material of the wire materials 64a, 64b is not particularly limited as long as it has corrosion resistance to the plating solution L. Examples of the material of the wire materials 64a, 64b include resin materials such as polyester resin. In addition, the mesh portion 64 may be made of a resin material such as acrylic resin, vinyl acetate resin, polyvinyl chloride resin, polypropylene resin, polyethylene resin, polystyrene resin, polycarbonate resin, polyimide resin, or urethane resin, as long as it is capable of forming wires.

[0039] The mask portion 65 is held by a sheet-like mesh portion 64. The mask portion 65 has through-holes 68 formed therein according to a predetermined pattern P. The mask portion 65 is a portion that is brought into close contact with the substrate B during film formation by pressure from the electrolyte membrane 13. The material of the mask portion 65 is not particularly limited as long as it can be brought into close contact with the substrate B. For example, the material of the mask portion 65 may be a rubber material such as silicone rubber (PMDS) or ethylene propylene diene rubber (EPDM). The hardness of the rubber material is preferably HS100 or less, more preferably HS50 or less, in Shore A hardness.

[0040] The mask portion 65 is made of an elastic material that undergoes compressive elastic deformation due to pressure from the electrolyte membrane 13. In order to ensure adhesion to the base material B, the amount of deformation in the thickness direction (pressing direction) of the mask portion 65 due to pressure from the electrolyte membrane 13 may be in the range of 5 to 20% of the thickness of the mask portion before deformation. The screen mask 62 having the predetermined pattern P can be manufactured by a general silk screen manufacturing technique using an emulsion. Therefore, a detailed description of the manufacturing method of the screen mask 62 will be omitted.

[0041] As shown in FIG. 4, the mask portion 65 includes a first portion 65a facing the electrolyte membrane 13 and a second portion 65b facing the substrate B. The mesh portion 64 is disposed between the first portion 65a and the second portion 65b, and holds the first portion 65a and the second portion 65b. That is, the mesh portion 64 is sandwiched between the first portion 65a and the second portion 65b, and the first portion 65a and the second portion 65b are connected through the opening 64c of the mesh portion 64. The force acting on the mesh portion 64 due to the liquid pressure of the plating solution L during film formation can be uniformly distributed to the second portion 65b. This makes it possible to uniformly deform the second portion 65b, thereby ensuring stable sealing between the mask portion 65 and the substrate B.

[0042] Furthermore, on the surface 65c of the mask portion 65 facing the electrolyte membrane 13, a cover sheet 30A is disposed to prevent contact between the mask portion 65 and the electrolyte membrane 13. The cover sheet 30A corresponds to the "contact prevention material" in the present invention. In this embodiment, the cover sheet 30A is preferably flexible, and as long as the plating solution L exuded from the electrolyte membrane 13 can be supplied to the through-portion 68 of the mask portion 65, the configuration is not limited, and the cover sheet 30A may be a resin (resin material) sheet material in which openings are formed according to the shape of the pattern P of the through-portion 68. In this embodiment, the cover sheet 30A has a plurality of openings 31c through which the plating solution L passes, at least at positions covering the through-portion 68. Examples of such a cover sheet 30A include a resin sponge-like sheet, a resin sheet in which a plurality of openings (through-holes) are formed, and the like. The resin material is a synthetic resin produced by a polymerization reaction or the like, so that fine particles do not adhere to the electrolyte membrane 13. Examples of such resin materials include acrylic resin, vinyl acetate resin, polyvinyl chloride resin, polypropylene resin, polyethylene resin, polystyrene resin, polycarbonate resin, polyimide resin, urethane resin, polyester resin, etc. In addition, super engineering plastics such as liquid crystal polymers may also be used.

[0043] The covering sheet 30A is preferably a sheet made of a mesh woven with wires 31a and 31b. The covering sheet 30A has a plurality of openings 31c, 31c, ... formed in a lattice pattern. Specifically, as shown in Figs. 2 and 4, the covering sheet 30A has a mesh-like portion (mesh) in which a plurality of oriented wires 31a, 31b are woven so as to cross each other. The plurality of wires 31a, 31a are arranged at intervals, and the plurality of wires 31b, 31b that cross these are arranged at intervals. As a result, the covering sheet 30A has a plurality of openings 31c, 31c, ... formed in a lattice pattern. The wires 31a and 31b are made of the resin material described above. The mesh openings 31c of the covering sheet 30A are larger than the mesh openings of the mesh portion 64. Specifically, the distance between the wires 31a, 31a (wires 32a, 32a) is greater than the distance between the wires 64a, 64a (64b, 64b).

[0044] A film forming method using the film forming apparatus 1 will be described with reference to FIGS. 1 to 4. First, a placement step is performed. In this step, as shown in FIG. 1, the substrate B is placed on the mounting table 40. Specifically, the substrate B is accommodated in the recess 41 of the mounting table 40. In this embodiment, with the substrate B accommodated in the recess 41, the surface of the substrate B protrudes from the opposing surface of the mounting table 40 (the surface facing the electrolyte membrane 13). This allows the mask portion 65 of the masking material 60 to be uniformly in contact with the surface of the substrate B. At this time, the alignment of the substrate B with respect to the anode 11 attached to the housing 15 is adjusted, and the temperature of the substrate B may be adjusted.

[0045] Next, the masking material 60 is placed on the mounting table 40. At this time, the masking material 60 is accommodated so that the surface of the base material B fits within the internal space 69 of the frame 61 of the masking material 60. Specifically, as shown in FIG. 4, the surface of the base material B (the surface of the base layer Bb) is covered with the mask portion 65 of the masking material 60. Furthermore, as shown in FIG. 2, the cover sheet 30A is placed so as to cover the opposing surface 65c of the mask portion 65.

[0046] Next, a pressing step is performed. In this step, the electrolyte membrane 13 presses the substrate B through the cover sheet 30A and the screen mask 62 by the liquid pressure of the plating solution L in contact with the electrolyte membrane 13. First, the linear actuator 70 is driven. This causes the container 15 to descend toward the cover sheet 30A and the masking material 60 from the state shown in FIG. 1 to the state shown in FIG. 3.

[0047] Next, the pump 80 is driven. As a result, the plating solution L is supplied to the accommodation space 15a of the accommodation body 15. Since the pressure regulating valve 54 is provided in the liquid discharge pipe 52, the liquid pressure of the plating solution L in the accommodation space 15a is maintained at a predetermined pressure. As a result, as shown in FIG. 4, the liquid pressure of the plating solution L causes the electrolyte membrane 13 to deform toward the internal space 69 of the frame 61, and the screen mask 62 can be sandwiched between the electrolyte membrane 13 and the substrate B. Furthermore, the electrolyte membrane 13 acting on the liquid pressure of the plating solution L can press the masking material 60.

[0048] 4, this pressing force allows the screen mask 62 to be tightly attached to the surface of the substrate B. Since the mask portion 65 is made of a rubber material, the mask portion 65 is compressed and elastically deformed by the liquid pressure of the plating solution L, improving the adhesion between the mask portion 65 and the substrate B. Furthermore, when the pressing force against the electrolyte membrane 13 is continued, the seepage liquid (plating solution) La that seeps out from the electrolyte membrane 13 swollen by the plating solution L fills the through portions 68 formed in the screen mask 62 and is pressurized.

[0049] Next, as shown in FIG. 4, a film forming process is performed. In this process, the pressing state by the electrolyte membrane 13 in the pressing process is maintained, and a metal film F is formed. Specifically, a voltage is applied between the anode 11 and the substrate B. This causes metal ions contained in the plating solution L to pass through the electrolyte membrane 13. The metal ions that have passed through the electrolyte membrane 13 move to the surface of the substrate B via the seeping liquid La, and are reduced on the surface of the substrate B. As a result, the metal ions of the plating solution L pass through the through-portion 68, and the passing metal ions are precipitated on the surface of the substrate B. In this way, as shown in FIG. 2, a metal film F of a predetermined pattern P according to the shape of the through-portion 68 can be formed on the surface of the substrate B.

[0050] Incidentally, in the film forming apparatus, when the covering sheet 30A is not used as a contact prevention material, as shown in FIG. 7, the electrolyte membrane 13 directly presses the mask portion 65 during film formation, so that the rubber particles C of the mask portion 65 adhere to the surface of the electrolyte membrane 13. When the electrolyte membrane 13 is slightly stretched by the liquid pressure of the plating solution L, the portion of the electrolyte membrane 13 to which the rubber particles C adhere is deformed so as to enter the through portion 68 formed in the mask portion 65. As a result, the movement of metal ions from the through portion 68 toward the substrate B during film formation is hindered by the rubber particles C adhered to the electrolyte membrane 13. This makes it difficult to form a metal coating F of a predetermined pattern P according to the shape of the through portion 68, as shown in FIG. 7. In particular, when the metal coating F is repeatedly formed, the electrolyte membrane 13 is stretched by the repeated liquid pressure, so that such a phenomenon becomes prominent.

[0051] However, in this embodiment, as shown in FIG. 4, a covering sheet (contact prevention material) 30A made of a resin material is arranged on the opposing surface 65c of the mask portion 65 that faces the electrolyte membrane 13. This makes it possible to prevent the electrolyte membrane 13 from directly contacting the opposing surface 65c of the mask portion 65 even if the electrolyte membrane 13 is deformed toward the mask portion 65 by the hydraulic pressure of the plating solution L. This makes it possible to prevent the rubber particles derived from the rubber material of the mask portion 65 from adhering to the electrolyte membrane 13. As a result, even if the electrolyte membrane 13 is deformed by the hydraulic pressure of the plating solution L, the movement of metal ions is not hindered by the rubber particles in the part of the electrolyte membrane 13 that covers the through portion 68 of the mask portion 65. Therefore, compared to the case shown in FIG. 7, the metal coating F of a predetermined pattern P can be formed on the substrate B with high accuracy.

[0052] In particular, in this embodiment, the cover sheet 30A is disposed so as to cover the through-hole portion 68 of the mask portion 65, and therefore it is possible to suppress slackness, etc., of the electrolyte membrane 13 that is deformed by the liquid pressure of the plating solution L. Furthermore, the liquid pressure can be uniformly applied to the mask portion 65 via the electrolyte membrane 13 and the cover sheet 30A. This makes it possible to make the deformation of the mask portion 65 uniform, and therefore it is possible to stably ensure the sealing performance between the mask portion 65 and the substrate B.

[0053] Furthermore, the covering sheet 30A has a plurality of openings 64c through which the plating solution L passes, at positions covering the through-holes 68, so that the seepage solution La (plating solution) seeping out from the electrolyte membrane 13 can pass through the openings 64c of the covering sheet 30A and be stably supplied to the through-holes 68. As a result, the metal coating F according to the pattern of the through-holes 68 can be stably formed on the surface of the substrate B.

[0054] Furthermore, since the mesh openings 31c of the covering sheet 30A are larger than the mesh openings 64c of the mesh portion 64, the seepage liquid La that seeps out from the electrolyte membrane 13 can be smoothly supplied to the through-holes 68 of the mask portion 65 through the openings of the covering sheet 30A. This allows the metal coating F to be stably formed on the surface of the substrate B in accordance with the pattern of the through-holes 68.

[0055] Thereafter, the linear actuator 70 raises the container 15, separates the substrate B from the electrolyte membrane 13, and removes the substrate B from the mounting table 40. When manufacturing wiring using the metal coating F, the conductive underlayer Bb formed on the surface of the insulating substrate Ba of the substrate B may be etched away, leaving the portion on which the metal coating F is formed.

[0056] A membrane forming apparatus according to a modified example will be described below with reference to Figures 5 and 6. In the membrane forming apparatus according to Figures 1 to 4, a cover sheet 30A is used on the surface facing the electrolyte membrane 13 as a contact prevention material for preventing contact between the mask portion 65 and the electrolyte membrane 13. In this modified example, instead of the cover sheet 30A, a resin film 30B is provided on the mask portion 65 as a contact prevention material.

[0057] In this embodiment, the resin film 30B made of a resin material (synthetic resin) is formed so as to cover the opposing surface 65c of the mask portion 65 that faces the electrolyte membrane 13. The resin film 30B is preferably flexible and is formed on the opposing surface 65c of the mask portion 65 as follows. As one film forming method, the opposing surface 65c of the mask portion 65 may be coated with an emulsion in which synthetic resin particles are dispersed in a liquid, and then dried to form the resin film 30B on the opposing surface 65c of the mask portion 65. As another film forming method, the resin film 30B may be formed on the opposing surface 65c of the mask portion 65 by coating the opposing surface 65c of the mask portion 65 with an uncured resin and then polymerizing the coated resin. As another film forming method, the resin film 30B may be formed on the opposing surface 65c of the mask portion 65 by attaching a resin film in which through holes having the same shape as the predetermined pattern P are formed on the opposing surface 65c of the mask portion 65.

[0058] Examples of the resin of the resin film 30B include fluororesins such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and perfluoroalkoxy fluororesin (PFA). By using a fluororesin for the resin film 30B, it is possible to reduce the friction of the surface of the resin film 30B. Therefore, even if the electrolyte membrane 13 presses against the mask portion 65 and stretches during repeated film formation, it is possible to prevent the electrolyte membrane 13 from being damaged by the resin film 30B.

[0059] Alternatively, the resin of the resin film 30B may be a polyester resin such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), or polyethylene naphthalate (PEN). By using a polyester resin for the resin film 30B, the flexibility of the resin film 30B can be increased. Therefore, even if the electrolyte membrane 13 presses against the mask portion 65 and stretches during repeated film formation, the electrolyte membrane 13 can be prevented from being damaged by the resin film 30B.

[0060] 6, in this modified example, the resin film 30B is disposed on the opposing surface 65c of the mask portion 65, so that the rubber particles of the mask portion 65 can be prevented from adhering to the electrolyte membrane 13. In addition, the seepage liquid La seeping out from the electrolyte membrane 13 is directly supplied to the through-holes 68 of the mask portion 65. In this manner, the metal film F having the desired pattern P can be stably formed. EXAMPLES

[0061] A masking part with a through-hole formed on both sides of a mesh part made of LCP resin with a line diameter of 20 μm and a mesh of 420 mesh was molded with silicone rubber. This produced a masking material having a mesh part and a masking part. Of the thicknesses of the masking part, the first part was 30 μm thick, and the second part was 20 μm thick. The through-hole had three different widths: 100 μm, 250 μm, and 500 μm. Next, a mesh covering sheet made of LCP resin with a line diameter of 20 μm and a mesh of 420 mesh was prepared.

[0062] Next, a square copper (Cu) substrate with a thickness of 0.9 mm and a side length of 7.8 cm was prepared, and cathodic electrolytic degreasing of the substrate was performed at 55°C for 1 minute using IC-200RM manufactured by JCU Corporation, and then the substrate was rinsed with pure water for 1 minute. Furthermore, the substrate was immersed in 10% diluted sulfuric acid at room temperature for 1 minute for acid cleaning, and then the substrate was rinsed with pure water for 1 minute.

[0063] Thereafter, as shown in Figure 4, a metal film having a thickness of 5 μm was formed on the surface of the substrate by solid-phase electrodeposition (SED) using an apparatus having the same configuration as the film-forming apparatus including the cover sheet. Specifically, before film formation, the masking material was pressed with the electrolyte membrane together with the cover sheet at a pressure of 0.6 MPa for 24 hours, and then the film was formed under the following film formation conditions. The film formation conditions were film formation temperature: 42°C, plating solution: 1 mol / l copper sulfate + 0.2 mol / l sulfuric acid, anode: phosphorus-containing copper plate, anode-cathode electrode distance: 2 mm, pressure: 0.6 MPa, film formation area: 38 cm 2 / Board size 61.4cm 2 , current: 7ASD.

[0064] As a comparative example, as shown in FIG. 7, a film was formed under the same conditions as in the example, without providing the mesh of the example. Defects in the film formed in the example and the comparative example were confirmed. As a result, the metal film of the example had no defects, while the metal film of the comparative example had eight defects. When the electrolyte membrane of the comparative example was checked, it was found that fine rubber particles were attached to the mask portion, which caused defects in the metal film.

[0065] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as described in the claims. [Explanation of symbols]

[0066] 1: film forming device, 11: anode, 13: electrolyte membrane, 30A: covering sheet (contact prevention material), 30B: resin film (contact prevention material), 60: masking material, 61: frame, 62: screen mask, 64: mesh part, 65: mask part, 65a: first part, 65b: second part, 65c: facing surface, 68: through part, B: substrate, F: metal film, L: plating solution

Claims

1. A metal film forming apparatus for forming a metal film having a predetermined pattern on a surface of a substrate by electrolytic plating, comprising: The film forming apparatus includes: a container having an opening formed at a position facing the base material, the opening being covered with an electrolyte membrane while containing a plating solution; a pressing mechanism that presses the substrate with the electrolyte membrane by a hydraulic pressure of the plating solution contained in the container; an anode disposed inside the container at a position facing the electrolyte membrane; a masking material disposed between the electrolyte membrane and the base material, the masking material having a through-portion of the predetermined pattern formed therein; the masking material has a mask portion made of a rubber material in which the through portion is formed, A metal film forming apparatus, wherein a contact prevention material made of a resin material is disposed on the surface of the mask portion that faces the electrolyte membrane, to prevent contact between the mask portion and the electrolyte membrane.

2. the contact prevention material is a covering sheet disposed on the opposing surface so as to cover the penetrating portion, The metal coating forming apparatus according to claim 1 , wherein the covering sheet has a plurality of openings through which the plating solution passes, at least at positions covering the through-portions.

3. the mask portion includes a first portion facing the electrolyte membrane and a second portion facing the substrate; 3. The metal coating deposition apparatus of claim 2, wherein the masking material has a mesh portion woven with wire, the mesh portion being disposed between the first portion and the second portion and holding the first portion and the second portion.

4. The covering sheet is a sheet made of a mesh woven with wires, The metal coating deposition apparatus according to claim 3 , wherein mesh openings of the covering sheet are larger than mesh openings of the mesh portion.

5. The metal film forming apparatus according to claim 1 , wherein the contact prevention material is a resin film coated on the facing surface.

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