Metal film forming apparatus

Abstract

This invention provides a metal film forming apparatus that uses a mask member having a mask portion made of rubber material to form a metal film with a specified pattern with high precision. The mask member (60) of the film forming apparatus (1) has a through portion (68) and a mask portion (65) made of rubber material. An insulating porous plate (30) is disposed between the electrolyte membrane (13) and the mask portion (65) to cover the through portion (68). The porous plate has a plurality of fine holes through which the electroplating solution passes.

Description

Technical Field

[0001] This invention relates to a film-forming apparatus for metal films. Background Technology

[0002] As an example of this technology, Patent Document 1 discloses a metal film forming apparatus comprising a mask member for forming a metal film with a predetermined pattern on the surface of a substrate by electroplating. The mask member has a mask portion having a through portion corresponding to the predetermined pattern. The mask portion is made of a rubber material.

[0003] During the formation of the metal film, a mask portion of a mask element is sandwiched between the electrolyte membrane and the substrate, and the electrolyte membrane is pressed towards the substrate by the hydraulic pressure of the electroplating solution. Under this pressed state, a metal film can be formed on the surface of the substrate by applying a voltage between the anode and the substrate.

[0004] [Existing technical documents]

[0005] [Patent Literature]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2024-63738 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, in the case where the mask portion of the mask component shown in Patent Document 1 is made of rubber material, during film formation, when the mask portion is pressed by the electrolyte membrane, the mask portion sometimes experiences uneven compression and deformation. As a result, it is difficult to form a metal film with a prescribed pattern corresponding to the shape of the through portion.

[0009] The present invention was made in view of the following problem, and its object is to provide a metal film forming apparatus capable of forming a metal film with a specified pattern using a mask member having a mask portion made of rubber material with high precision.

[0010] Methods for solving problems

[0011] In view of the above-mentioned problems, the metal film forming apparatus of the present invention is a metal film forming apparatus that forms a metal film with a predetermined pattern on the surface of a substrate by electrolytic electroplating. The film forming apparatus includes: a housing having an opening at a position opposite to the substrate, wherein the opening is covered by an electrolyte membrane when an electroplating solution is contained therein; a pressing mechanism that uses the electroplating solution contained in the housing to press the substrate with the electrolyte membrane; an anode disposed inside the housing at a position opposite to the electrolyte membrane; and a mask member disposed between the electrolyte membrane and the substrate, having a through portion having the predetermined pattern formed thereon. The mask member has a mask portion having the through portion formed thereon and made of a rubber material. A porous plate is disposed between the electrolyte membrane and the mask portion to cover the through portion, the porous plate having a plurality of fine holes through which the electroplating solution passes.

[0012] In one embodiment, the mask portion includes a first portion facing the electrolyte membrane and a second portion facing the substrate. The mask also has a mesh portion woven from wires, disposed between the first and second portions, and holding both portions in place.

[0013] As a further embodiment, the mask includes a frame that secures the periphery of the mesh portion. The porous plate is disposed between the electrolyte membrane and the mask portion in a free-restrained state relative to the frame.

[0014] As another option, the mask portion is fixed to one of the surfaces of the porous plate opposite to the substrate. A mesh made of woven wire is installed around the periphery of the porous plate in a manner that surrounds the porous plate. The outer periphery of the mesh is fixed to a frame.

[0015] As another option, the porous plate is made of chemically strengthened glass, and the pores are through holes formed along the thickness direction of the porous plate.

[0016] Invention Effects

[0017] According to the present invention, a metal film with a specified pattern can be formed with high precision using a mask having a mask portion made of rubber material. Attached Figure Description

[0018] Figure 1 This is a schematic cross-sectional view illustrating an example of a film-forming apparatus for a metal film according to an embodiment of the present invention.

[0019] Figure 2 It means Figure 1A schematic perspective view of the porous plate, the mask, and the substrate with the metal film formed thereon.

[0020] Figure 3 It is used to illustrate the use Figure 1 A schematic cross-sectional view of the film-forming apparatus shown.

[0021] Figure 4 It is used to illustrate the use Figure 3 A schematic cross-sectional view of the metal film formation process performed by the film-forming apparatus shown.

[0022] Figure 5 (a) is Figure 4 (a) is a schematic cross-sectional view of a modified film-forming apparatus shown, and (b) is a schematic cross-sectional view of another modified film-forming apparatus.

[0023] Figure 6 It means Figure 2 A schematic perspective view of a modified example of the mask shown.

[0024] Figure 7 (a) is used Figure 6 (a) is a schematic cross-sectional view of the film-forming apparatus of the mask shown, and (b) is a schematic cross-sectional view of the film-forming apparatus of another variation. Detailed Implementation

[0025] The film-forming apparatus 1 for the metal film according to an embodiment of the present invention will be described. Figure 1 This is a schematic cross-sectional view illustrating an example of a film-forming apparatus for a metal film according to an embodiment of the present invention.

[0026] like Figure 1 As shown, the film-forming apparatus 1 is a film-forming apparatus that forms a metal film F with a predetermined pattern P on the substrate B by electrolytic electroplating with a mask 60 sandwiched between the electrolyte membrane 13 and the substrate B. Specifically, the film-forming apparatus 1 includes an anode 11, an electrolyte membrane 13, and a power supply 14 that applies a voltage between the anode 11 and the substrate B.

[0027] The film-forming apparatus 1 includes: a housing 15 containing an anode 11 and an electroplating solution L, a stage 40 for holding a substrate B, and a mask 60. During film formation, the mask 60 and the substrate B are placed together on the stage 40. An electrolyte membrane 13 is disposed between the mask 60 and the anode 11.

[0028] The film-forming apparatus 1 includes a direct-acting actuator 70 that raises and lowers the housing 15. In this embodiment, for ease of explanation, it is assumed that the electrolyte membrane 13 is disposed below the anode 11, and then the mask 60 and the substrate B are disposed below it. However, this positional relationship is not limited as long as a metal film F can be formed on the surface of the substrate B.

[0029] Substrate B functions as a cathode. Substrate B is a plate-shaped substrate. In this embodiment, substrate B is a rectangular substrate. The opposing surface of substrate B, which faces the electrolyte membrane 13 (screen mask 62), is the film-forming surface that functions as a cathode. As long as it functions as a cathode (i.e., a conductive surface), the material of substrate B is not particularly limited. Substrate B can be made of metallic materials such as aluminum or copper.

[0030] In this embodiment, such as Figure 2 As shown, a pattern (wiring pattern) P is formed by a metal film F. Therefore, a substrate B, on which a base layer Bb, such as copper, is formed on the surface of an insulating substrate Ba, such as a resin substrate, is used as the substrate. In this case, after the metal film F is formed, the base layer Bb, except for the portion on which the metal film F is formed, is removed by etching or the like. Thus, a pattern P based on the metal film F can be formed on the surface of the insulating substrate Ba.

[0031] As an example, the anode 11 is a non-porous (e.g., non-porous) anode made of the same metal as the metal film. The anode 11 has a blocky or plate-like shape. Examples of materials for the anode 11 include copper. The anode 11 dissolves upon application of voltage from the power supply 14. However, in the case where film formation is performed using only metal ions from the electroplating solution L, the anode 11 is an anode that is insoluble relative to the electroplating solution L. The anode 11 is electrically connected to the positive terminal of the power supply 14. The negative terminal of the power supply 14 is electrically connected to the substrate B via the mounting stage 40.

[0032] Electroplating solution L is a liquid containing the metal to be formed into a film in an ionic state. Examples of such metals include copper, nickel, gold, silver, or iron. Electroplating solution L is a solution prepared by dissolving (ionizing) these metals with acids such as nitric acid, phosphoric acid, succinic acid, sulfuric acid, or pyrophosphate. Examples of solvents for this solution include water and alcohol. For example, in the case of copper, an aqueous solution containing copper sulfate, copper pyrophosphate, etc., can be used as electroplating solution L.

[0033] The electrolyte membrane 13 is a membrane that can impregnate (contain) metal ions together with the electroplating solution L by contacting it. 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 in the electroplating solution L can move to the substrate B side when a voltage is applied through the power supply 14. Examples of materials for the electrolyte membrane 13 include fluorinated resins with ion exchange functions, such as Nafion (registered trademark) manufactured by DuPont. The membrane thickness of the electrolyte membrane 13 is preferably in the range of 20 μm to 200 μm. More preferably, its thickness is in the range of 20 μm to 60 μm.

[0034] The housing 15 is made of a material insoluble in the electroplating solution L. A housing space 15a for containing the electroplating solution L is formed in the housing 15. An anode 11 is disposed in the housing space 15a. An opening 15d is formed on the substrate B side of the housing space 15a. The opening 15d of the housing 15 is covered by an electrolyte membrane 13. Specifically, the periphery of the electrolyte membrane 13 is held between the housing 15 and the frame 17. Thus, the electroplating solution L within the housing space 15a can be sealed using the electrolyte membrane 13.

[0035] like Figure 1 as well as Figure 3 As shown, the direct-acting actuator 70 raises and lowers the housing 15 to allow the electrolyte membrane 13 to freely contact and separate from the mask member 60. In this embodiment, the stage 40 is fixed, and the housing 15 is raised and lowered by the direct-acting actuator 70. The direct-acting actuator 70 is an electric actuator that converts the rotational motion of a motor into direct motion via a ball screw or the like (not shown). However, a hydraulic or pneumatic actuator can also be used instead of an electric actuator.

[0036] A supply flow path 15b is formed in the housing 15 to supply the electroplating solution L to the housing space 15a. Furthermore, a discharge flow path 15c is formed in the housing 15 to discharge the electroplating solution L from the housing space 15a. The supply flow path 15b and the discharge flow path 15c are holes communicating with the housing space 15a. The supply flow path 15b and the discharge flow path 15c are formed across the housing space 15a. The supply flow path 15b is fluidly connected to the liquid supply pipe 51. The discharge flow path 15c is fluidly connected to the liquid discharge pipe 52.

[0037] The film-forming apparatus 1 also includes a liquid tank 90, a liquid supply pipe 51, a liquid discharge pipe 52, and a pump 80. For example... Figure 1 As shown, electroplating solution L is contained in liquid tank 90. ​​Liquid supply pipe 51 connects liquid tank 90 and housing 15. Pump 80 is provided in liquid supply pipe 51. Pump 80 supplies electroplating solution L from liquid tank 90 to housing 15. Liquid discharge pipe 52 connects liquid tank 90 and housing 15. Pressure regulating valve 54 is provided in liquid discharge pipe 52. Pressure regulating valve 54 adjusts the pressure (hydraulic pressure) of electroplating solution L in housing space 15a to a specified pressure.

[0038] In this embodiment, the electroplating solution L is drawn from the liquid tank 90 into the liquid supply pipe 51 by the drive pump 80. The drawn electroplating solution L is pressurized from the supply flow path 15b to the receiving space 15a. The electroplating solution L in the receiving space 15a returns to the liquid tank 90 via the discharge flow path 15c. In this way, the electroplating solution L circulates within the film forming apparatus 1.

[0039] Furthermore, by continuously driving the pump 80, the hydraulic pressure of the electroplating solution L in the receiving space 15a can be maintained at a predetermined pressure using the pressure regulating valve 54. The pump 80 presses the mask member 60 through the porous plate 30 using the electrolyte membrane 13 acted upon by the hydraulic pressure of the electroplating solution L. However, the pressing mechanism is not particularly limited as long as the electrolyte membrane 13 can press the mask member 60. An injection mechanism consisting of a piston and cylinder for injecting the electroplating solution L can also be used instead of the pump 80.

[0040] As an example, the mounting stage 40 is formed of a conductive material (e.g., metal). A recess 41 is formed in the mounting stage 40. The recess 41 is a portion recessed from the opposite side of the mounting stage 40 to accommodate the substrate B.

[0041] The mask member 60 includes a frame 61 and a screen printing mask 62. The frame 61 supports the periphery 62a of the screen printing mask 62 on the electrolyte membrane 13 side. Specifically, the periphery of the screen printing mask 62 is fixed to the frame 61. In this embodiment, the screen printing mask 62 has a rectangular shape. Therefore, the frame 61 has a rectangular border shape. The material of the frame 61 is not particularly limited as long as the shape of the mask member 60 can be maintained. For example, metal materials such as stainless steel or resin materials such as thermoplastic resin can be used as materials for the frame 61. The frame 61 is formed, for example, by stamping a metal sheet and has a thickness of about 1 mm to 3 mm.

[0042] The screen printing mask 62 has a through portion 68 corresponding to a predetermined pattern P of the metal film F. The screen printing mask 62 includes a grid portion 64 and a mask portion 65. The screen printing mask 62 is a flexible mask with a thickness of approximately 50 μm to 400 μm. The screen printing mask 62 is supported on the surface of the substrate B side of the frame 61.

[0043] The periphery of the mesh portion 64 is fixed to the frame 61. The mesh portion 64 is stretched under a prescribed tension to cover the openings of the frame 61. The mesh portion 64 is formed in a lattice pattern with multiple openings. Specifically, as... Figure 4 As shown, the mesh portion 64 is composed of a mesh-like section (mesh) formed by multiple oriented wires woven together in a cross-shaped manner. The multiple wires are arranged spaced apart from each other, and the multiple wires that cross them are also arranged spaced apart from each other. Thus, multiple openings are formed in the mesh portion 64 in a lattice-like pattern. The material of the wires is not particularly limited, as long as the wires are resistant to corrosion by the electroplating solution L. For example, resin materials such as polyester resin can be used as wire materials. In addition, as long as wires can be formed, the mesh portion 64 can also be made of resin materials such as acrylic resin, vinyl acetate resin, polyvinyl chloride resin, polypropylene resin, polyethylene resin, polystyrene resin, polycarbonate resin, polyimide resin, or polyurethane resin.

[0044] The mask portion 65 is held in place by the sheet-like mesh portion 64. A through portion 68 corresponding to the predetermined pattern P is formed in the mask portion 65. The mask portion 65 is the portion that adheres tightly to the substrate B during film formation by pressing from the electrolyte membrane 13. The material is not limited as long as it can adhere tightly to the substrate B, but in this embodiment, the mask portion 65 is made of a rubber material. For example, silicone rubber (PMDS) or ethylene propylene diene monomer (EPDM) rubber can be used as the material for the mask portion 65. The hardness of the rubber material, measured on a Shore A hardness scale, is preferably HS100 or less, and more preferably HS50 or less.

[0045] The mask portion 65 is made of an elastic material that is compressed and elastically deformed by pressure from the electrolyte membrane 13. To ensure adhesion to the substrate B, the amount of deformation in the thickness direction (extrusion direction) of the mask portion 65 relative to the thickness of the mask portion before deformation can be in the range of 5% to 20% by extrusion from the electrolyte membrane 13. The screen printing mask 62 having a predetermined pattern P can be manufactured using general screen printing techniques using emulsions. Therefore, a detailed description of the manufacturing method of the screen printing mask 62 is omitted.

[0046] like Figure 4 As shown, the mask portion 65 includes a first portion 65a facing the electrolyte membrane 13 and a second portion 65b facing the substrate B. A mesh portion 64 is disposed between the first portion 65a and the second portion 65b, holding both portions together. Specifically, 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 via an opening 64c in the mesh portion 64. This allows the force acting on the mesh portion 64 due to the hydraulic pressure of the electroplating solution L during film formation to be evenly distributed in the second portion 65b. Consequently, the deformation of the second portion 65b is uniform, thus ensuring a stable seal between the mask portion 65 and the substrate B.

[0047] In this embodiment, a porous plate 30 is disposed between the electrolyte membrane 13 and the mask portion 65. The porous plate 30 is a plate with multiple fine holes through which the electroplating solution L passes. The porous plate 30 is not particularly limited as long as it is electrically insulated relative to the anode 11, but in this embodiment, the material of the porous plate 30 is preferably a material with a high Young's modulus, such as resin materials like polyetheretherketone (PEEK), acrylic resin, and polytetrafluoroethylene (PTFE), glass such as chemically strengthened glass, and ceramics such as alumina. The porous plate 30 may also be used to insulate the surface of a metal plate body. The porous plate 30 is preferably made of chemically strengthened glass. It should be noted that the Young's modulus of chemically strengthened glass is approximately 76,100 MPa.

[0048] As described above, a plurality of fine holes through which the electroplating solution L passes are formed in the porous plate 30. Furthermore, during film formation, electrolysis occurs in the plurality of fine holes, extending from the anode 11 towards the substrate B. In this embodiment, when the porous plate 30 is made of chemically strengthened glass, the fine holes are through-holes formed along the thickness direction of the porous plate 30. Such fine holes can be formed by laser processing or the like. In this embodiment, the diameter of the fine holes is preferably 50 μm to 100 μm, and the spacing between the fine holes is preferably 50 μm to 100 μm. By satisfying these ranges, the rigidity of the porous plate 30 can be ensured, and the electroplating solution L is supplied from the porous plate 30 through the fine holes to the through-holes 68, forming a homogeneous wiring pattern.

[0049] The porous plate 30 is configured to cover the through portion 68 of the mask portion 65. As described above, the mask member 60 has a frame 61 that fixes the periphery of the mesh portion 64. The porous plate 30 is configured between the electrolyte membrane 13 and the mask portion 65 in a non-constrained state relative to the frame 61. In this embodiment, the porous plate 30 is detachably disposed on the surface of the mask portion 65 facing the electrolyte membrane 13. Alternatively, the porous plate 30 may be integrally fixed to the mask portion 65.

[0050] Reference Figures 1-4 The film-forming method using film-forming apparatus 1 will be described. First, a preparation step is performed. In this step, as follows... Figure 1 As shown, substrate B is disposed on the mounting stage 40. Specifically, substrate B is received in the recess 41 of the mounting stage 40. In this embodiment, with substrate B received in the recess 41, the surface of substrate B protrudes from the opposing surface (the surface opposite to the electrolyte membrane 13) of the mounting stage 40. As a result, the mask portion 65 of the mask member 60 can be made into uniform contact with the surface of substrate B.

[0051] Next, the mask 60 is placed on the stage 40. At this time, the mask 60 is housed within the internal space of the frame 61 of the mask 60 in a manner that accommodates the surface of the substrate B. Specifically, as follows... Figure 4 As shown, the surface of the substrate B is covered by the mask portion 65 of the mask member 60. Furthermore, the porous plate 30 is configured to cover all through portions 68 formed in the mask portion 65.

[0052] Next, a pressing process is performed. In this process, the electroplating solution L, in contact with the electrolyte membrane 13, is hydraulically applied to the substrate B via the porous plate 30 and the printing mask 62, pressing the substrate B with the electrolyte membrane 13. First, the direct-acting actuator 70 is driven. Thus, from Figure 1 The state shown Figure 3 The state shown causes the housing 15 to descend toward the porous plate 30 and the mask 60.

[0053] Next, the pump 80 is driven. This supplies electroplating solution L to the receiving space 15a of the housing 15. A pressure regulating valve 54 is provided in the liquid discharge pipe 52, so the hydraulic pressure of the electroplating solution L in the receiving space 15a is maintained at a predetermined pressure. As a result, the hydraulic pressure of the electroplating solution L allows the porous plate 30 and the printing screen mask 62 to be sandwiched between the electrolyte membrane 13 and the substrate B. Furthermore, the electrolyte membrane 13, acted upon by the hydraulic pressure of the electroplating solution L, can press against the printing screen mask 62.

[0054] like Figure 4 As shown, this pressing action allows the mask portion 65 to adhere tightly to the surface of the substrate B. Since the mask portion 65 is formed of rubber, it undergoes compressive elastic deformation due to the hydraulic pressure of the electroplating solution L, thus improving the adhesion between the mask portion 65 and the substrate B. In this embodiment, a porous plate 30 is disposed between the electrolyte membrane 13 and the mask portion 65. Therefore, the electrolyte membrane 13 presses the mask portion 65 through the porous plate 30 under the hydraulic pressure of the electroplating solution L. This allows the mask portion 65 to undergo uniform compressive elastic deformation.

[0055] Furthermore, since the porous plate 30 is in an unconstrained state, it can follow the deformation of the mask portion 65 during pressing. As a result, even if the porous plate 30 is made of a brittle material such as chemically strengthened glass, the stress acting on the porous plate 30 can be reduced. This improves the durability of the porous plate 30. If the electrolyte membrane 13 is pressed continuously, the electroplating solution L seeps out from the electrolyte membrane 13, which swells due to the electroplating solution L. The seeped out liquid (electroplating solution) La fills the through portion 68 formed in the printing mask 62 through the fine pores of the porous plate 30 and is pressurized.

[0056] Next, a film-forming process is performed. In this process, the electrolyte membrane 13 is kept under pressure while the metal film F is formed. Specifically, a voltage is applied between the anode 11 and the substrate B. This causes the metal ions contained in the electroplating solution L to pass through the electrolyte membrane 13. The metal ions passing through the electrolyte membrane 13 move to the surface of the substrate B via the exudate La and are reduced on the surface of the substrate B. As a result, the metal ions in the electroplating solution L pass through the through-hole 68 and are deposited on the surface of the substrate B. Thus, as Figure 2 As shown, a metal film F with a predetermined pattern P corresponding to the shape of the through portion 68 can be formed on the surface of the substrate B. In this way, by uniformly deforming the mask portion 65 made of rubber material, the metal film F with the predetermined pattern P can be formed with high precision and homogeneity.

[0057] However, in conventional film-forming apparatuses, the electrolyte membrane sometimes penetrates into the mask portion with each film-forming cycle, causing the mesh portion to deform to the surface of the substrate. Consequently, a pattern corresponding to the shape of the mesh portion 64 is sometimes formed on the metal film. However, in this embodiment, the porous plate 30 is configured to cover the through portion 68 of the mask portion 65, thus preventing the electrolyte membrane 13 from entering the through portion 68. As a result, a homogeneous metal film F can be formed.

[0058] Subsequently, the housing 15 is raised using the direct-acting actuator 70, separating the substrate B from the electrolyte membrane 13, and the substrate B is removed from the stage 40. It should be noted that when manufacturing wiring using the metal film F, the portion where the metal film F is formed is retained, and the conductive base layer Bb formed on the surface of the insulating substrate Ba of the substrate B is etched.

[0059] The following is for reference Figures 5-7 The film-forming apparatus of the modified example is described. Figures 1-4 In the film-forming apparatus, the mask portion 65 is held by the mesh portion 64 of the mask member 60, but in the following modifications, the mask portion 65 is held by the porous plate 30. That is, the structures of the mask member 60 are different in these modifications. Therefore, in the following modifications, only the different structures will be described.

[0060] Specifically, such as Figure 5 (a) and Figure 5 As shown in (b), in this modified example, the porous plate 30 is fixed to the frame 61. Figure 5 (a) and Figure 5 In (b), a mask portion 65 is integrally formed on one of the two surfaces of the porous plate 30 facing the substrate B. Unlike the mesh portion, the porous plate 30 is not easily deformed by the pressure of the electrolyte membrane 13, thus improving the forming accuracy of the pattern P of the metal film F.

[0061] Furthermore, in Figure 5 In (b), a buffer portion 69 corresponding to the shape of the mask portion 65 is formed on one of the two surfaces of the porous plate 30 facing the electrolyte membrane 13. The buffer portion 69 is made of the same material as the mask portion 65, but its material is not particularly limited as long as it can be elastically deformed by pressure from the electrolyte membrane 13. By providing such a buffer portion 69, the portion of the electrolyte membrane 13 in contact with the porous plate 30 can be reduced during film formation, and damage to the electrolyte membrane 13 caused by contact with the porous plate 30 can be suppressed.

[0062] exist Figure 6In the modified example shown, a mask portion 65 is integrally formed on the surfaces of both sides of the porous plate 30 facing the substrate B. A mesh 32 made of woven wire is installed around the periphery 31 of the porous plate 30 to surround the porous plate 30. The mesh 32 is rectangular and may be made of the same material and wire as illustrated in the mesh portion above. The center of the mesh 32 is open to match the size of the rectangular porous plate 30. The inner periphery of the central opening (not shown) of the mesh 32 is fixed with adhesive or the like in a state of overlapping with the periphery 31 of the porous plate 30. The outer periphery of the mesh 32 is fixed to the surface 61a of the frame 61 by adhesive or the like.

[0063] According to this modified example, the porous plate 30 is constrained to the frame 61 by a flexible mesh 32. Therefore, by pressing the electrolyte membrane 13, the mesh 32 flexes, allowing the porous plate 30 to follow the deformation of the mask portion 65. This suppresses damage caused by the deformation of the porous plate 30 and improves its durability. If the electrolyte membrane 13 is pressed continuously, the electroplating solution L seeps out from the electrolyte membrane 13, which swells due to the electroplating solution L. The seeping exudate (electroplating solution) La fills the through-holes 68 formed in the mask portion 65 through the fine pores of the porous plate 30 and is pressurized. Moreover, since the mask portion 65 is integrally formed with the porous plate 30, thus... Figure 7 As shown in (a), the portion of the mask portion 65 other than the thickness direction can be deformed. This improves the forming accuracy of the pattern P of the metal film F.

[0064] Furthermore, in Figure 7 In (b), a buffer portion 69 corresponding to the shape of the mask portion 65 is formed on one of the two surfaces of the porous plate 30 facing the electrolyte membrane 13. The buffer portion 69 is made of the same material as the mask portion 65, but its material is not particularly limited as long as it can elastically deform under pressure from the electrolyte membrane 13. By providing such a buffer portion 69, the portion of the electrolyte membrane 13 in contact with the porous plate 30 can be reduced during film formation, suppressing damage to the electrolyte membrane 13 caused by contact with the porous plate 30. Furthermore, as... Figure 7 As shown in (b), if the mask portion 65 and the buffer portion 69 are sandwiched into the mesh 32, leakage of the exudate La from the electrolyte membrane 13 from the vicinity of the frame 61 can be reduced.

[0065] [Example]

[0066] Use respectively Figure 1 The film-forming apparatus shown and Figure 5A metal film is formed using a film-forming apparatus of a modified example (a). A mask portion with through-holes is formed on both sides of a 20 μm diameter, 420 mesh LCP resin mesh portion using silicone rubber molding. Thus, a mask component having the mesh portion and the mask portion is fabricated. It should be noted that the thickness of the first portion of the mask portion is 30 μm, and the thickness of the second portion is 20 μm. Next, a chemically strengthened glass with a thickness of 200 μm, a pore size of 100 μm, and a spacing of 100 μm is prepared as a porous plate. A substrate on which copper (Cu) is formed by sputtering is prepared on a wafer having a square surface with a side length of 5 mm.

[0067] Then, using an apparatus identical in construction to the film-forming apparatus containing the porous plate, a 2.5 μm thick metal film was formed on the surface of the substrate by solid-phase electrolysis (SED) under vacuum. The film-forming conditions were as follows: film-forming temperature: 40°C; plating solution: 1M copper sulfate and 0.2M sulfuric acid; anode: iridium oxide electrode (insoluble anode); anode-cathode distance: 5 mm; pressure: 0.6 MPa; holding time: 10 minutes; current: 3.5 ASD.

[0068] As a comparative example, the porous plate of the embodiment is not provided, and the following is used. Figure 1 The film-forming apparatus shown was used to form a film under the same conditions as in the embodiment. Defects in the film formation of the embodiment and the comparative example were confirmed. As a result, no defects were found in the metal film of the embodiment, while a pattern corresponding to the shape of the grid portion of the mask was formed in the metal film of the comparative example. Therefore, it can be seen that, as in the embodiment, a homogeneous metal film can be formed by providing a porous plate.

[0069] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments. Various design changes can be made without departing from the spirit of the present invention as set forth in the claims.

[0070] [Explanation of reference numerals in the attached figures]

[0071] 1: Film forming apparatus; 11: Anode; 13: Electrolyte membrane; 30: Porous plate; 60: Mask component; 61: Frame; 62: Screen printing mask; 64: Mesh portion; 65: Mask portion; 65a: First part; 65b: Second part; 65c: Opposite face; 68: Through portion; B: Substrate; F: Metal film; L: Electroplating solution.

Claims

1. A metal film forming apparatus, wherein the metal film forming apparatus forms a metal film with a predetermined pattern on the surface of a substrate by electrolytic electroplating, wherein, The film-forming apparatus includes: The container has an opening at a position opposite to the substrate, and when it contains an electroplating solution, the opening is covered by an electrolyte membrane. The pressing mechanism uses the hydraulic pressure of the electroplating solution contained in the containment to press the substrate using the electrolyte membrane; The anode is located inside the containment body and positioned opposite the electrolyte membrane. as well as A mask element, disposed between the electrolyte membrane and the substrate, has a through portion having the prescribed pattern. The mask component has a mask portion formed with the through portion and made of rubber material. A porous plate is disposed between the electrolyte membrane and the mask portion to cover the through portion. The porous plate has a plurality of fine pores through which the electroplating solution can pass.

2. The film-forming apparatus for the metal film according to claim 1, wherein, The mask portion has a first portion facing the electrolyte membrane and a second portion facing the substrate. The mask has a mesh portion made of woven wire, the mesh portion being disposed between the first portion and the second portion and holding the first portion and the second portion together.

3. The metal film forming apparatus according to claim 2, wherein, The mask component includes a frame that fixes the periphery of the mesh portion. The porous plate is disposed between the electrolyte membrane and the mask portion in a state of non-constraint relative to the frame.

4. The film-forming apparatus for the metal film according to claim 1, wherein, The mask portion is fixed on one of the surfaces of the porous plate opposite to the substrate. A mesh made of woven wire is installed around the periphery of the porous plate in a manner that surrounds the porous plate. The outer periphery of the grid is fixed to the frame.

5. The film-forming apparatus for a metal film according to claim 1, wherein, The porous plate is made of chemically strengthened glass, and the pores are through holes formed along the thickness direction of the porous plate.

Images