Metal film deposition equipment

Abstract

To provide a film-forming apparatus for a metal coating that can suppress damage to an electrolyte membrane during pressing, even when using a mask structure.SOLUTION: A film-forming apparatus 1 includes a pressing mechanism that uses an electrolyte membrane 13 to press a mask structure 60 through hydraulic pressure from a plating solution L. The mask structure 60 includes a screen mask 62 with through-holes 68 corresponding to a specific pattern, and a frame 61 that supports the periphery 62a of the screen mask 62 on the substrate B side. The frame 61 includes an inner covering section 66A made from a softer elastic material than the frame 61 material, formed along an opening edge 61a in contact with the electrolyte membrane 13.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] The present invention relates to a film forming apparatus for forming a metal film in a predetermined pattern on the surface of a substrate. [Background technology]

[0002] Conventionally, there have been proposed film formation devices that deposit metal on the surface of a substrate to form a metal coating (for example, Patent Document 1). In Patent Document 1, the film formation device includes a container that contains a plating solution. The container has an opening that is sealed with an electrolyte membrane. The film formation device further includes a pressing mechanism that presses the electrolyte membrane against the substrate using the hydraulic pressure of the plating solution.

[0003] Here, when a metallic underlayer with a predetermined pattern is formed on the surface of the substrate, a voltage is applied between the anode and the substrate while the substrate is pressed by the hydraulic pressure of the electrolyte membrane. This allows a metallic coating with the predetermined pattern to be formed on the underlayer. However, when a underlayer with the predetermined pattern is not formed on the substrate, it is also conceivable to use a masking material such as that shown in Patent Document 2. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-125087 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-108586 Summary of the Invention [Problem to be solved by the invention]

[0005] When a film is formed using a mask structure having a screen mask as a masking material, the mask structure is sandwiched between a substrate and an electrolyte membrane. In this state, the electrolyte membrane, to which the hydraulic pressure of the plating solution acts, is pressed against the mask structure to ensure close contact between the substrate and the screen mask. However, because the frame supporting the periphery of the screen mask is supported by the substrate, the electrolyte membrane may be pressed against the opening edge of the frame, potentially damaging the electrolyte membrane.

[0006] The present invention has been made in consideration of these points, and aims to provide a metal film forming device that can suppress damage to the electrolyte membrane when pressed, even when a mask structure is used. [Means for solving the problem]

[0007] In view of the above problems, the present invention provides a metal film forming apparatus that forms a metal film of a predetermined pattern on a substrate by electrolytic plating, with a mask structure sandwiched between an electrolyte membrane and the substrate. The film forming apparatus includes a pressing mechanism that presses the mask structure with the electrolyte membrane using hydraulic pressure of a plating solution. The mask structure includes a screen mask having perforations formed according to the predetermined pattern, and a frame that supports the periphery of the screen mask on the substrate side. The frame is formed with an inner covering portion made of an elastic material softer than the material of the frame along an opening edge that contacts the electrolyte membrane.

[0008] According to the present invention, first, a mask structure is sandwiched between an electrolyte membrane and a substrate, and then a pressing mechanism presses the mask structure with the electrolyte membrane, to which the hydraulic pressure of the plating solution acts. Because the peripheral edge of the screen mask is supported by a frame on the substrate side, the screen mask can be tightly attached to the surface of the substrate. By pressing the electrolyte membrane, the seepage liquid (plating solution) that seeps out from the electrolyte membrane swollen by the plating solution fills the perforated portions of the screen mask. Because the perforated portions are shaped according to a predetermined pattern, a metal coating of the predetermined pattern can be formed on the surface of the substrate by electrolytic plating.

[0009] Here, the frame supporting the periphery of the screen mask is supported on the substrate side, so the hydraulic pressure of the plating solution presses the electrolyte membrane toward the edge of the opening of the frame. Even in such a case, the inner covering portion is formed along the edge of the opening of the frame and is made of an elastic material softer than the material of the frame, so that elastic deformation of the inner covering portion and damage to the electrolyte membrane can be prevented. Furthermore, because the frame is harder than the inner covering portion, even if the frame is pressed by the electrolyte membrane, the shape of the frame is less likely to deform, and the screen mask can maintain its adhesion to the substrate.

[0010] For example, an outer covering portion made of the soft elastic material may be further formed along the outer peripheral edge of the frame body facing the electrolyte membrane.

[0011] During membrane formation, the electrolyte membrane may be pressed toward the outer periphery of the frame due to the hydraulic pressure of the plating solution. Even in such a case, the outer coating portion is formed along the outer periphery of the frame facing the electrolyte membrane and is made of an elastic material softer than the material of the frame, so that elastic deformation of the outer coating portion and damage to the electrolyte membrane can be prevented.

[0012] For example, the opposing surface formed between the opening edge and the outer peripheral edge and facing the electrolyte membrane may be coated with the soft elastic material so that the inner coating portion and the outer coating portion are continuous.

[0013] According to this example, the force with which the electrolyte membrane presses against the frame can be dispersed over the entire soft elastic material, thereby preventing stress from acting locally on the electrolyte membrane.

[0014] For example, the film forming apparatus may include a mounting table for mounting the substrate. The mounting table may have a first recess for accommodating the substrate and a second recess for accommodating the mask structure with the substrate accommodated in the first recess. The mounting table may have an edge covering portion made of the soft elastic material formed along an opening edge of the second recess.

[0015] During film formation, the electrolyte membrane may be pressed against the edge of the opening of the second recess in the mounting table due to the hydraulic pressure of the plating solution. Even in such a case, the mounting table has an edge covering portion formed along the edge of the opening of the second recess, so that the electrolyte membrane can be prevented from being damaged.

[0016] For example, the screen mask may have a mesh portion having openings formed in a grid pattern, and a mask portion fixed to the mesh portion on the substrate side of the mesh portion and having the through-portions formed therein, and the mask portion may be elastically deformed by pressure from the electrolyte membrane.

[0017] According to this example, during film formation, the electrolyte membrane presses the masked portion due to the hydraulic pressure of the plating solution. This pressure from the electrolyte membrane causes the masked portion to elastically deform, thereby maintaining the adhesion of the masked portion to the substrate. [Effects of the Invention]

[0018] According to the present invention, even when a mask structure is used, damage to the electrolyte membrane when pressed can be suppressed. [Brief explanation 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. [Figure 2] 2 is a schematic perspective view of a mask structure of the film forming apparatus shown in FIG. 1 and a schematic perspective view of a substrate on which a metal film has been formed. [Figure 3A] FIG. 3 is a partially enlarged cross-sectional view taken along line AA shown in FIG. 2. [Figure 3B] FIG. 3B is an enlarged cross-sectional view of part C in FIG. 3A. [Figure 4] FIG. 2 is a schematic cross-sectional view for explaining film formation by the film formation apparatus shown in FIG. [Figure 5A] FIG. 5 is a cross-sectional view of a main part of FIG. 4. [Figure 5B] FIG. 3C is a cross-sectional view of the portion shown in FIG. 3B during film formation. [Figure 6] 1 is a flowchart illustrating an example of a method for forming a metal film using a film forming apparatus according to an embodiment of the present invention. [Figure 7A] 10 is a partial cross-sectional view of a mask structure of a film forming apparatus according to a first modified example. FIG. [Figure 7B] FIG. 10 is a partial cross-sectional view of a mask structure of a film forming apparatus according to a second modification. [Figure 7C] FIG. 11 is a partial cross-sectional view of a mask structure of a film forming apparatus according to a third modified example. [Figure 8] 10 is an enlarged partial cross-sectional view of a mounting table of a film forming apparatus according to a fourth modification. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] First, a metal film forming apparatus 1 according to an embodiment of the present invention will be described. Fig. 1 is a schematic cross-sectional view showing an example of a metal film forming 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 with a mask structure 60 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 formation apparatus 1 includes a container 15 that contains an anode 11 and a plating solution L, a mounting table 40 on which a substrate B is placed, and a mask structure 60. During film formation, the mask structure 60 is placed on the mounting table 40 together with the substrate B. The electrolyte membrane 13 is disposed between the mask structure 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 mask structure 60 and the substrate B are disposed further below that. However, as long as the metal coating 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 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. When forming a wiring pattern from the metal coating F, the substrate B is a substrate in which a base layer of copper or the like is formed on the surface of an insulating substrate such as a resin. In this case, after forming the metal coating F, the base layer other than the portion on which the metal coating F is formed is removed by etching or the like. This allows a wiring pattern made of the metal coating F to be formed on the surface of the insulating substrate.

[0025] 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 flat plate shape. Examples of materials for the anode 11 include copper. The anode 11 dissolves when a voltage is applied from the power source 14. However, when forming a film using only 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.

[0026] The plating solution L is a solution containing the metal of the metal coating to be formed in an ionic state. Examples of such metals 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 for 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.

[0027] The electrolyte membrane 13 is a membrane that can be impregnated (contain) metal ions together with the plating solution L by contacting it 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 it allows the metal ions of the plating solution L to migrate to the substrate B side when a voltage is applied from the power source 14. Examples of materials for the electrolyte membrane 13 include resins with ion exchange properties, such as fluororesins such as Nafion (registered trademark) manufactured by DuPont. The thickness of the electrolyte membrane 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.

[0028] The container 15 is made of a material that is insoluble in the plating solution L. The container 15 has a container space 15a that contains the plating solution. 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 that faces the substrate B. The opening 15d of the container 15 is covered with an 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.

[0029] 1 and 4, the linear actuator 70 raises and lowers the housing 15 so that the electrolyte membrane 13 and the mask structure 60 can be moved toward and away 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 that converts the rotational motion of a motor into linear motion using a ball screw or the like (not shown). However, instead of the electric actuator, a hydraulic or pneumatic actuator may be used.

[0030] The container 15 is formed with a supply flow path 15b that supplies the plating solution L to the container space 15a. Furthermore, the container 15 is formed with a discharge flow path 15c that discharges the plating solution L from the container space 15a. The supply flow path 15b and the discharge flow path 15c are holes that communicate 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 connected to a liquid supply pipe 50. The discharge flow path 15c is fluidly connected to a liquid discharge pipe 52.

[0031] The film forming apparatus 1 further includes a liquid tank 90, a liquid supply pipe 50, a liquid discharge pipe 52, and a pump 80. As shown in FIG. 1 , the liquid tank 90 contains a plating solution L. The liquid supply pipe 50 connects the liquid tank 90 to the accommodation body 15. The liquid supply pipe 50 is provided with a pump 80. The pump 80 supplies the plating solution L from the liquid tank 90 to the accommodation body 15. The liquid discharge pipe 52 connects the liquid tank 90 to 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 solution L in the accommodation space 15a to a predetermined pressure.

[0032] In this embodiment, the plating solution L is sucked from the liquid tank 90 into the liquid supply pipe 50 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.

[0033] 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 mask structure 60 with the electrolyte membrane 13 acting on the liquid pressure of the plating solution L. Therefore, the pump 80 corresponds to the "pressure mechanism" of the present invention. However, the pressure mechanism is not particularly limited as long as it can press the mask structure 60 with the electrolyte membrane 13. Instead of the pump 80, an injection mechanism consisting of a piston and a cylinder that injects the plating solution may be used.

[0034] The mounting table 40 is made of, for example, a conductive material (e.g., metal). The mounting table 40 has a first recess 41 and a second recess 42. The first recess 41 is a recess that accommodates the substrate B. The second recess is a recess that accommodates the mask structure 60 with the substrate B accommodated in the first recess 41.

[0035] Fig. 2 is a schematic perspective view of the mask structure 60 of the film forming apparatus 1 shown in Fig. 1 and a schematic perspective view of the substrate B on which a metal film F is formed. Fig. 3A is a partially enlarged cross-sectional view taken along line AA shown in Fig. 2, and Fig. 3B is an enlarged cross-sectional view of part C in Fig. 3A.

[0036] The mask structure 60 includes a frame body 61 and a screen mask 62. The screen mask 62 has through-holes 68 formed therein 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.

[0037] The mesh portion 64 has a plurality of openings 64c, 64c, ... formed in a lattice pattern. Specifically, as shown in FIG. 3B , the mesh portion 64 is a mesh-like portion in which a plurality of oriented wires 64a, 64b are woven so as to intersect. The plurality of wires 64a, 64a are arranged at intervals, and the plurality of wires 64b, 64b that intersect with the plurality of wires 64a, 64a are also arranged at intervals. As a result, a plurality of openings 64c, 64c, ... are formed in a lattice pattern in the mesh portion 64. The material of the wires 64a, 64b is not particularly limited as long as it is corrosion-resistant to the plating solution L. Examples of materials for the wires 64a, 64b include metal materials such as stainless steel and resin materials such as polyester.

[0038] The mask portion 65 is fixed to the mesh portion 64 on the substrate B side of the 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 adheres closely to the substrate B during membrane formation due to pressure from the electrolyte membrane 13. The material of the mask portion 65 is not particularly limited as long as it can adhere closely to the substrate B. It is preferable that the mask portion 65 undergoes compressive elastic deformation due to pressure from the electrolyte membrane 13. Examples of materials for the mask portion 65 include resin materials such as acrylic resin, vinyl acetate resin, polyvinyl resin, polyimide resin, and polyester resin. The screen mask 62 having the predetermined pattern P can be manufactured using a general silkscreen manufacturing technique using an emulsion. Therefore, a detailed description of the manufacturing method of the screen mask 62 will be omitted.

[0039] The frame 61 supports a peripheral edge 62a of the screen mask 62 on the substrate B side (the mounting table 40 side) of 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 mask structure 60. For example, the material of the frame 61 can be a metal material such as stainless steel or a resin material such as a thermoplastic resin. The frame 61 is formed, for example, by punching a metal plate and has a thickness of approximately 1 mm to 3 mm. Note that in FIG. 3A and other figures, the thickness of the frame 61 is depicted as being thicker than its actual thickness for ease of explanation.

[0040] A covering portion 66 is formed on the surface of the frame body 61. The covering portion 66 is made of an elastic material that is softer than the material of the frame body 61. The covering portion 66 includes an inner covering portion 66A, an outer covering portion 66B, and a flat covering portion 66C.

[0041] 3A and 5A, the inner covering portion 66A is formed along the opening edge 61a of the frame body 61 that contacts the electrolyte membrane 13. The inner covering portion 66A covers the opening edge 61a of the frame body 61. Here, the opening edge 61a of the frame body 61 is a ridge (edge ​​portion) formed by an opposing surface 61c that faces the electrolyte membrane 13 and an inner circumferential surface 61d that forms the internal space 69 of the frame body 61. The inner covering portion 66A has an extending portion 66D that extends from the opening edge 61a along the inner circumferential surface 61d.

[0042] The outer covering portion 66B is formed along the outer peripheral edge 61b of the frame body 61 facing the electrolyte membrane 13. The outer covering portion 66B covers the outer peripheral edge 61b of the frame body 61. Here, the outer peripheral edge 61b of the frame body 61 is a ridge (edge ​​portion) formed by the opposing surface 61c facing the electrolyte membrane 13 and the outer peripheral surface 61e of the frame body 61. The outer covering portion 66B has an extending portion 66E extending from the outer peripheral edge 61b along the outer peripheral surface 61e.

[0043] The flat covering portion 66C is formed on the surface (opposing surface) 61c between the opening edge 61a and the outer peripheral edge 61b. The flat covering portion 66C covers the opposing surface 61c. The flat covering portion 66C makes the inner covering portion 66A and the outer covering portion 66B into a single continuous portion. In this embodiment, as shown in FIG. 3A, the covering portion 66 is formed on a portion excluding the surface to which the peripheral edge 62a of the screen mask 62 is fixed.

[0044] The covering portion 66 is made of an elastic material that is softer than the material of the frame 61. The material of the covering portion 66 is not particularly limited as long as it can avoid damaging the electrolyte membrane 13. It is preferable that the covering portion 66 undergoes compressive elastic deformation due to pressure from the electrolyte membrane 13. For example, the covering portion 66 can be made of 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. Note that a "soft elastic material" refers to a material that has a relatively low hardness, measured using a durometer of a predetermined standard, and a low Young's modulus in a tensile test. The thickness of the covering portion 66 is thinner than the thickness of the frame 61. Specifically, the thickness of the covering portion 66 is preferably in the range of approximately 1 / 5 to 1 / 10 of the thickness of the frame 61.

[0045] 4 to 6, a film formation method using the film formation apparatus 1 will be described. First, an arrangement step S1 is performed as shown in FIG. 6. In this step, the substrate B and the mask structure 60 are arranged on the mounting table 40. Specifically, the substrate B is accommodated in the first recess 41 of the mounting table 40, and then the mask structure 60 is accommodated in the second recess 42. At this time, the alignment of the substrate B with respect to the anode 11 attached to the housing body 15 is adjusted, and the temperature of the substrate B may also be adjusted.

[0046] Next, a pressing step S2 is performed. In this step, first, the linear actuator 70 is driven to lower the accommodation body 15 toward the mask structure 60 from the state shown in FIG. 1 to the state shown in FIG. 4 . Next, the pump 80 is driven. This supplies the plating solution L to the accommodation space 15a of the accommodation body 15. Because the pressure adjustment 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 electrolyte membrane 13 is deformed toward the internal space 69 of the frame 61 due to the liquid pressure, and the mask structure 60 can be sandwiched between the electrolyte membrane 13 and the substrate B. Furthermore, the electrolyte membrane 13, acting on by the liquid pressure of the plating solution L, can press the mask structure 60.

[0047] 4 and 5A, the peripheral edge 62a of the screen mask 62 is supported by the frame 61 on the side of the substrate B, so that the screen mask 62 can be brought into close contact with the surface of the substrate B. If 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.

[0048] Furthermore, as the pressure on the electrolyte membrane 13 continues, as shown in Figures 5A and 5B, the seepage liquid (plating liquid) La that seeps out from the electrolyte membrane 13 swollen by the plating liquid L fills the through-holes 68 formed in the screen mask 62.

[0049] 5A, a peripheral edge 62a of the screen mask 62 is supported on the substrate B side relative to the frame 61. Due to this support, when the liquid pressure of the plating solution L acts on the electrolyte membrane 13, the electrolyte membrane 13 is pressed against the opening edge 61a of the frame 61 and the outer peripheral edge 61b of the frame 61.

[0050] An inner covering portion 66A made of an elastic material softer than the material of the frame body 61 is formed along the opening edge 61a of the frame body 61. Furthermore, an outer covering portion 66B made of an elastic material softer than the material of the frame body 61 is formed along the outer peripheral edge 61b of the frame body 61 facing the electrolyte membrane 13. This allows the inner covering portion 66A and the outer covering portion 66B to elastically deform, preventing damage to the electrolyte membrane 13.

[0051] 5A, in particular, when the opposing surface 61c of the frame 61 protrudes toward the electrolyte membrane 13 beyond the opposing surface 40a of the mounting table 40, the electrolyte membrane 13 is likely to be damaged by the outer peripheral edge 61b of the frame 61. When a gap is formed between the side surface 42a of the second recess 42 and the outer peripheral surface 61e of the frame 61, the electrolyte membrane 13 is also likely to be damaged by the outer peripheral edge 61b of the frame 61.

[0052] However, by providing the outer covering portion 66B on the frame 61 as in this embodiment, it is possible to prevent the outer covering portion 66B from elastically deforming and damaging the electrolyte membrane 13. Furthermore, if a gap is formed between the side surface 42a of the second recess 42 and the outer peripheral surface 61e of the frame 61, the outer covering portion 66B functions as a sealant and can prevent the plating solution L from entering this gap.

[0053] Furthermore, the flat covering portion 66C forms a surface 61c facing the electrolyte membrane so that the inner covering portion 66A and the outer covering portion 66B are continuous, and the facing surface 61c is covered with a soft elastic material. This allows the force of the electrolyte membrane 13 pressing against the frame 61 to be dispersed across the entire soft elastic material. As a result, it is possible to prevent stress from acting locally on the electrolyte membrane 13.

[0054] The frame 61 is harder than the inner covering portion 66A. Therefore, even if the frame 61 is pressed by the electrolyte membrane 13, the shape of the frame 61 is less likely to deform, and the screen mask 62 can maintain close contact with the substrate B.

[0055] Next, the film-forming step S3 is performed. In this step, the pressing state of the electrolyte membrane 13 in the pressing step S2 is maintained, and a metal film F is formed. Specifically, a voltage is applied between the anode 11 and the substrate B. As a result, metal ions contained inside the electrolyte membrane 13 migrate to the surface of the substrate B via the oozing liquid La, and the metal ions are reduced on the surface of the substrate B. The oozing liquid La filled in the through-holes 68 is sealed inside the through-holes 68 by the electrolyte membrane 13, so that a metal film F having a predetermined pattern can be formed on the surface of the substrate B (see FIG. 2). Furthermore, the oozing liquid La is uniformly pressurized by the pressing of the electrolyte membrane 13, so that a homogeneous metal film F can be formed. When manufacturing wiring using the metal film F, it is sufficient to etch the conductive underlayer formed on the surface of the insulating substrate B.

[0056] <Modification> 7A to 7C are partial cross-sectional views of mask structures of film formation apparatuses according to Modifications 1 to 3. These modifications differ from the embodiment shown in Fig. 3A in the form of the covering portion covering the frame body 61 of the mask structure 60. Therefore, only the differences from the above-described embodiment will be described, and detailed descriptions of similar configurations will be omitted.

[0057] For example, when the electrolyte membrane 13 does not directly contact the outer peripheral edge 61b of the frame 61, only the inner covering portion 66A may be formed on the frame 61, as shown in Fig. 7A. Alternatively, the inner covering portion 66A and the outer covering portion 66B may be separately formed on the frame 61, as shown in Fig. 7B. According to the second modification shown in Fig. 7B, in the pressing step S2 and the membrane-forming step S3, the pressing of the electrolyte membrane 13 causes the inner covering portion 66A and the outer covering portion 66B to elastically deform independently, thereby preventing damage to the electrolyte membrane 13.

[0058] 7C, the covering portion 66 is formed on the entire surface of the frame body 61. That is, in the third modification, a bottom covering portion 66F made of a softer elastic material than the material of the frame body 61 is also formed between the frame body 61 and the peripheral edge 62a of the screen mask 62. Therefore, the bottom covering portion 66F is elastically deformed by the pressure of the electrolyte membrane 13, thereby improving the adhesion between the mask structure 60 and the substrate B.

[0059] 8 is a partially enlarged cross-sectional view of the mounting table 40 of the film formation apparatus 1 according to Modification 4. In Modification 4, the mounting table 40 has an edge covering portion 48 formed along the opening edge 42b of the second recess 42, the edge covering portion 48 being made of a softer elastic material than the material of the frame 61. As a result, even if the electrolyte membrane 13 is pressed against the opening edge 42b of the second recess 42 by the hydraulic pressure of the plating solution L during film formation, the edge covering portion 48 elastically deforms, preventing damage to the electrolyte membrane 13.

[0060] In particular, when the opposing surface 40a of the mounting table 40 protrudes toward the electrolyte membrane 13 beyond the opposing surface 61c of the frame 61, the electrolyte membrane 13 is likely to be damaged by the opening edge 42b of the second recess 42. Therefore, by providing the edge covering portion 48, damage to the electrolyte membrane 13 can be avoided. Furthermore, in this embodiment, the edge covering portion 48 and the covering portion 66 are made of the same elastic material, so that wear due to contact between the edge covering portion 48 and the outer covering portion 66B can be reduced. [Example]

[0061] The invention is illustrated by the following examples.

[0062] [Example] A glass epoxy substrate was prepared as a substrate for film formation, in which a layer of glass fiber cloth was impregnated with epoxy resin. Copper foil was formed on the surface of this glass epoxy substrate. Next, a copper film was formed using the film formation apparatus according to the embodiment shown in FIG. 1. The mask structure was a stainless steel frame with a silicone rubber coating having a Shore A hardness of HS50. A copper sulfate aqueous solution (Cu-BRITE-SED) manufactured by JCU Corporation was used as the plating solution, and a Cu plate was used as the anode. Nafion (registered trademark) manufactured by DuPont was used as the electrolyte membrane. The electrochemical film formation conditions were a plating solution temperature of 42°C, a plating solution pressure of 1 MPa, and a current density of 7 A / dm 2 A copper film was formed with a cumulative pressing time of 500 seconds.

[0063] [Comparative Example] A copper film was formed in the same manner as in Example 1. The difference from Example 1 is that the mask structure does not have a covering portion on the stainless steel frame.

[0064] The state of the electrolyte membrane in the membrane forming apparatus of the Example and Comparative Example after membrane formation was confirmed. The electrolyte membrane in the membrane forming apparatus of the Example was not damaged. On the other hand, the electrolyte membrane in the membrane forming apparatus of the Comparative Example was damaged.

[0065] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the film forming apparatus according to the above embodiments, and includes all aspects encompassed by the concept and scope of the present invention. Furthermore, each configuration may be appropriately and selectively combined to achieve the above-described problems and effects. For example, the shape, material, arrangement, size, etc. of each component in the above embodiments may be appropriately modified depending on the specific aspects of the present invention. [Explanation of symbols]

[0066] 1: film forming device, 13: electrolyte membrane, 40: mounting table, 41: first recess, 42: second recess, 42b: opening edge, 60: mask structure, 61: frame, 62: screen mask, 64: mesh portion, 65: mask portion, 61a: opening edge, 61b: outer peripheral edge, 66A: inner covering portion, 66B: outer covering portion, 68: penetration portion, B: substrate, F: metal coating, L: plating solution

Claims

1. A film formation apparatus that forms a metal film of a predetermined pattern on a substrate by electrolytic plating in a state in which a mask structure is sandwiched between an electrolyte membrane and the substrate, the film forming apparatus includes a pressing mechanism that presses the mask structure with the electrolyte membrane by hydraulic pressure of a plating solution; The mask structure comprises: a screen mask having through-holes formed therein according to the predetermined pattern; a frame that supports a periphery of the screen mask on the substrate side, The screen mask comprises: a mesh portion in which a plurality of wires are woven together so as to cross each other, and a plurality of openings are formed in a lattice pattern; a mask portion fixed to the mesh portion on the substrate side of the mesh portion, the mask portion having the through-portion formed therein, and the mask portion being in close contact with the substrate when the metal coating film is formed, the mask portion is elastically deformed by pressure from the electrolyte membrane, an inner covering portion made of a rubber material softer than the material of the frame is formed on the frame along an opening edge that contacts the electrolyte membrane; an outer covering portion made of the soft rubber material is further formed along an outer peripheral edge of the frame body facing the electrolyte membrane, a membrane forming device, wherein an opposing surface formed between the opening edge and the outer peripheral edge and facing the electrolyte membrane is covered with the soft rubber material so that the inner covering portion and the outer covering portion are continuous.

2. a mounting table on which the substrate is placed, the mounting table is formed with a first recess for accommodating the substrate, and a second recess for accommodating the mask structure with the substrate accommodated in the first recess, The film deposition apparatus according to claim 1 , wherein the mounting table has an edge covering portion made of the soft elastic material formed along an edge of an opening of the second recess.

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