JP7035971B2 - Metal film film formation method - Google Patents

Description

The present invention relates to a film forming method for forming a metal film on the surface of a base material.

As this kind of technology, for example, a solid electrolyte membrane is placed between the anode and the substrate which is the cathode, and a voltage is applied between the anode and the substrate to reduce the metal ions contained in the solid electrolyte membrane. However, a film forming method for forming a metal film on the surface of a substrate is used (see, for example, Patent Document 1).

The metal solution containing the metal ion that is the raw material of the metal film is housed in the cylindrical housing so as to contact the anode, and the solid electrolyte membrane covers one opening of the housing. It is fixed to the end face of. As a result, the metal ions of the metal solution contained in the housing are supplied to the solid electrolyte membrane.

When forming a metal film, the substrate is placed on a mounting table, the anode is placed above the substrate via the solid electrolyte membrane, and the substrate is pressed from above with the solid electrolyte membrane. A voltage is applied between the board and the board. As a result, the metal ions contained in the solid electrolyte film are reduced, and a metal film is formed on the surface of the substrate.

Japanese Unexamined Patent Publication No. 2016-0233338

However, as shown in Patent Document 1, when the anode is arranged above and the substrate is arranged below the solid electrolyte membrane, the solid electrolyte membrane can withstand the weight of the metal solution when the tensile elongation of the solid electrolyte membrane is large. The solid electrolyte membrane may bend.

If the solid electrolyte membrane is brought into contact with the substrate during film formation while the amount of deflection of the solid electrolyte membrane is large, the solid electrolyte membrane protrudes from the end face of the housing, and the solid electrolyte membrane is formed between the end face of the housing and the substrate. It may be pinched. If the film is repeatedly formed in such a state, the solid electrolyte film may be cracked and damaged. As a result, the metal solution may leak from the housing and the metal film may not be formed.

The present invention has been made in view of these points, and an object thereof is to prevent damage to a solid electrolyte membrane and to form a metal film in a stable manner. To provide a method.

In view of the above problems, the method for forming a metal film according to the present invention presupposes that a solid electrolyte membrane is arranged between the anode and the substrate which is the cathode, and the anode and the solid electrolyte membrane are in contact with each other. By arranging a metal solution containing metal ions so as to be in contact with the surface of the substrate and applying a voltage between the anode and the substrate in a state where the solid electrolyte membrane is in contact with the surface of the substrate, the solid electrolyte membrane is formed. The contained metal ions are reduced to form a metal film on the surface of the substrate.

In the method for forming a metal film, the solid electrolyte film is formed so that one of the circular openings among the openings at both ends of the tubular housing in which the metal solution is accommodated is covered with the solid electrolyte film. Is fixed to the end face of the housing, and the metal film is formed.

Before forming the metal film, the one opening of the housing is turned downward, and the metal solution adjusted to the temperature conditions at the time of forming the metal film is injected into the housing through the other opening. Then, using a laser displacement meter, the maximum amount of deflection of the solid electrolyte membrane located at the center of the one opening is measured.

When the maximum amount of deflection is equal to or less than the radius of one of the openings, the anode is placed above the solid electrolyte membrane and the substrate is placed below the solid electrolyte membrane to form the metal film. ..

On the other hand, when the maximum amount of deflection is larger than the radius of the one opening, the maximum stress acting on the solid electrolyte membrane is calculated from the maximum amount of deflection, and the maximum stress is the maximum stress of the solid electrolyte membrane. When it is equal to or less than the tensile breaking strength, the substrate is placed above the solid electrolyte membrane and the anode is placed below to form the metal film, and the maximum stress is the solid. If it is larger than the tensile breaking strength of the electrolyte membrane, the metal film is not formed.

According to the present invention, when the maximum amount of deflection of the solid electrolyte membrane due to the weight of the metal solution is equal to or less than the radius of one of the openings, the anode is arranged above and the substrate is arranged below with the solid electrolyte membrane interposed therebetween. Even if a metal film is formed, the solid electrolyte film is hardly sandwiched between the end face of the housing and the substrate. Therefore, in this case, damage to the solid electrolyte film can be reduced, and a metal film can be stably formed.

On the other hand, when the maximum amount of deflection of the solid electrolyte membrane is larger than the radius of one opening, the anode is placed above the solid electrolyte membrane and the substrate is placed below to form a metal film. There is a high possibility that the solid electrolyte membrane will be sandwiched between the end face of the housing and the substrate.

Therefore, in such a case, first, the maximum stress acting on the solid electrolyte membrane is calculated from the maximum amount of deflection. When the calculated maximum stress is equal to or less than the tensile breaking strength of the solid electrolyte film, the substrate is placed above the solid electrolyte film and the anode is placed below the solid electrolyte film to form a metal film. As a result, the solid electrolyte film is suppressed from bending due to the weight of the metal solution during film formation, so that it is possible to prevent the solid electrolyte film from being sandwiched between the end face of the housing and the substrate. The tensile breaking strength of the solid electrolyte membrane is the stress at which the material breaks when the same material as the solid electrolyte membrane is subjected to a tensile test.

On the other hand, when the calculated maximum stress of the solid electrolyte membrane is larger than the tensile breaking strength of the solid electrolyte membrane, if the weight of the metal solution acts on the solid electrolyte membrane when setting the solid electrolyte membrane, the solid electrolyte The membrane may be damaged. Therefore, in such a case, the optimum conditions under which the metal film can be formed can be examined without forming the metal film.

It is a schematic conceptual diagram of the metal film film forming apparatus which concerns on this embodiment of this invention. It is a flow chart of the film formation method of the metal film shown in FIG. It is a figure for demonstrating the measuring method of the maximum bending amount of the solid electrolyte membrane in the film forming apparatus shown in FIG. It is a figure for demonstrating the calculation method of the maximum stress of a solid electrolyte membrane from the maximum bending amount of a solid electrolyte membrane measured in FIG.

Hereinafter, a method for forming a metal film according to an embodiment of the present invention and a film forming apparatus capable of preferably carrying out the film forming method will be described.

1. 1. About the metal film forming apparatus 1A FIG. 1 is a schematic conceptual diagram of the metal film forming apparatus 1A according to the present embodiment of the present invention. Note that FIG. 1 shows a case where the anode 11 is arranged above the solid electrolyte film 13 and the substrate B is arranged below to form the metal film F (steps S5 and S6 in FIG. 2). However, the vertical positional relationship between the anode 11 sandwiching the solid electrolyte membrane 13 and the substrate B is determined according to a flow chart described later.

As shown in FIG. 1, the film forming apparatus 1A according to the present invention is an apparatus in which a metal is deposited from metal ions and a metal film composed of the deposited metal is formed on the surface of the base material B. Here, the base material B is, for example, a base material made of a metal material such as aluminum, or a base material having a metal base layer formed on the treated surface of a resin or silicon base material.

The film forming apparatus 1A includes a metal anode 11, a solid electrolyte film 13 arranged on the surface of the anode 11 between the anode 11 and the base material B serving as a cathode, and a base material B serving as the anode 11 and the cathode. It is provided with at least a power supply unit 14 for applying a voltage between the two.

The positive electrode of the power supply unit 14 is electrically connected to the film forming apparatus 1A so as to be conductive to the anode 11, and the cathode of the power supply unit 14 is electrically connected to the film forming region of the base material B. , Electrically connected to the film forming apparatus 1A or the substrate B.

The anode 11 is housed in a housing 15 that supplies a solution (hereinafter referred to as a metal solution) L containing metal ions for film formation to the anode 11. The housing 15 is made of a metal such as titanium and has a cylindrical shape, and the anode 11 and the metal solution (plating liquid) L are housed in the internal space thereof.

In the present embodiment, the solid electrolyte membrane 13 is formed so that one of the circular openings 15a of the openings 15a and 15b at both ends of the housing 15 in which the metal solution L is housed is covered with the solid electrolyte membrane 13. It is fixed to the end face 15d of the housing 15. More specifically, in the present embodiment, the housing 15 has a bottomed cylindrical shape, one circular opening 15a is formed in the center of the bottom 15e, and the solid electrolyte membrane 13 is the bottom of the housing 15. It is adhesively fixed to the end surface 15d corresponding to the outer surface of 15e, and one opening 15a is sealed.

Further, the opening 15b on the other side of the housing 15 is covered with the lid 15c, and the pressurizing means 16 is connected to the lid 15c. The pressurizing means 16 pressurizes the solid electrolyte film 13 on the film formation region of the substrate B by moving the housing 15 toward the substrate B. For example, as the pressurizing means 16, a hydraulic or pneumatic cylinder or the like can be mentioned. The film forming apparatus 1A includes a base 21 for fixing the base material B and adjusting the alignment of the base material B with respect to the anode 11.

A solution tank 17 containing a metal solution L is connected to one side of the housing 15 via a supply pipe 17a, and a waste liquid tank 18 for collecting used waste liquid is connected to the other side. It is connected via a tube 18a.

With this configuration, for example, before and after the formation of the metal film, the metal solution L stored in the solution tank 17 is supplied to the inside of the housing 15 via a pump or the like arranged in the supply pipe 17a. To. In the housing 15, the metal solution L flows into the porous anode 11. The metal solution L that has passed through the anode 11 can be sent to the waste liquid tank 18 via the waste liquid pipe 18a.

In the present embodiment, the anode 11 is fixed to the housing 15 so as to be in contact with the solid electrolyte membrane 13, and the metal solution L permeates through the anode 11 and supplies the metal ions of the metal solution L to the solid electrolyte membrane 13. It consists of a body. The anode 11 has a lower ionization tendency (or a higher electrode potential) than the metal ions of the metal solution L, such as titanium foam, and may be a foamed metal body composed of open cells having open pores.

The solid electrolyte membrane 13 can be impregnated with metal ions by contacting it with the above-mentioned metal solution L, and when a voltage is applied, the metal derived from the metal ions is deposited on the surface of the base material B. If possible, it is not particularly limited. Examples of the material of the solid electrolyte membrane include fluorine-based resin such as Nafion (registered trademark) manufactured by DuPont, hydrocarbon resin, polyamic acid resin, and ion exchange such as Celemion (CMV, CMD, CMF series) manufactured by Asahi Glass Co., Ltd. Examples thereof include resins having a function.

The film thickness of the solid electrolyte membrane 13 is preferably in the range of 20 to 60 μm, and the equivalent weight (equivalent gram) thereof is preferably in the range of 500 to 1000 g / mol. The tensile breaking strength of the solid electrolyte film 13 is preferably in the range of 300 to 500 kg / cm ² , and the tensile elongation thereof is preferably in the range of 150 to 400%. The dimensional change is preferably 4 to 30% or less. Further, the longitudinal elastic modulus of the solid electrolyte membrane is preferably 2000 to 6000 kg / cm ² .

In the present embodiment, the anode 11 is a porous body as a device for forming the metal film F, but as described later, if the metal ion can be supplied to the solid electrolyte film 13, the anode and the anode 11 are used. A gap may be provided between the solid electrolyte membrane and the metal solution to flow between the gaps. Further, the anode 11 may be a soluble anode made of the same material as the metal film F.

2. 2. Regarding the method of forming the metal film, the method of forming the metal film F according to the present embodiment will be described with reference to FIGS. 2 to 4. First, in step S1 shown in FIG. 2, before the metal film F is formed, one opening 15a of the housing 15 is turned downward, and the metal film F is formed in the housing 15 from the other opening 15b. The metal solution L adjusted to the temperature condition (for example, 80 ° C.) of the metal solution L at the time is injected. The amount of the metal solution L injected into the housing 15 corresponds to the amount of the metal solution L contained in the housing 15 at the time of film formation. At this time, the anode 11 may be fixed to the housing 15.

Next, the process proceeds to step S2, and the metal solution L in the housing 15 is held for a certain period of time while being kept warm so that the temperature does not drop. The holding time is the time for continuously forming the metal film F. As a result, the weight of the metal solution L acts on the solid electrolyte membrane 13, and the portion of the solid electrolyte membrane 13 that covers one opening 15a of the housing swells (deflects) downward.

Next, the process proceeds to step S3, and since the amount of deflection of the solid electrolyte membrane 13 located at the center of one opening 15a is the largest, in the present embodiment, the laser displacement meter 8 is used at the center of one opening 15a. The maximum amount of deflection of the located solid electrolyte membrane 13 is measured. In the present embodiment, the laser displacement meter 8 measures the displacement of the solid electrolyte membrane 13 before injecting the metal solution L into the housing 15, injects the metal solution L into the housing 15, and then holds the solid for a certain period of time. The displacement of the electrolyte membrane 13 is measured, and the maximum amount of deflection of the solid electrolyte membrane 13 is measured from the difference between these displacements.

When the solid electrolyte membrane 13 is less affected by the heat of the metal solution L (effect of deformation), the displacement of the solid electrolyte membrane 13 at the time of injecting the metal solution L into the housing 15 is measured, and this displacement is used. , The maximum amount of deflection may be measured from the difference from the displacement of the solid electrolyte membrane 13 before injecting the metal solution L.

Next, the process proceeds to step S4, and it is determined whether or not the maximum amount of deflection of the solid electrolyte membrane 13 is larger than the radius of one of the openings 15a. Here, if the maximum bending amount of the solid electrolyte film 13 is not larger than the radius of one opening 15a, that is, if the maximum bending amount is equal to or less than the radius of one opening 15a, the process proceeds to step S5. As shown in FIG. 1, the anode 11 is arranged above the solid electrolyte membrane 13 and the substrate B is arranged below. Next, the process proceeds to step S6 to form a metal film F (that is, a solid phase electrodeposition method is carried out).

Specifically, in step S5, as shown in FIG. 1, the base material B is arranged on the base 21, the alignment of the base material B is adjusted with respect to the anode 11, and the temperature of the base material B is adjusted. Next, the solid electrolyte membrane 13 is arranged on the surface of the anode 11 made of a porous body, and the solid electrolyte membrane 13 is brought into contact with the base material B.

Next, the solid electrolyte membrane 13 is pressed against the base material B by moving the anode 11 toward the base material B using the pressurizing means 16. Next, using the power supply unit 14, a voltage is applied between the anode 11 and the base material B serving as the cathode. As a result, the metal ions in the solid electrolyte membrane 13 move from the anode 11 side to the base material B side, and the metal ions contained in the solid electrolyte membrane 13 are reduced, so that the metal derived from the metal ions is produced. It is deposited on the surface of the base material B. As a result, the metal film F can be formed on the surface of the base material B.

As described above, when the maximum amount of deflection of the solid electrolyte membrane 13 due to the weight of the metal solution L is equal to or less than the radius of one opening 15a, the anode 11 is arranged above the solid electrolyte membrane 13 and the substrate B is below. Even if the metal film F is formed by arranging the solid electrolyte film 13, the bending of the solid electrolyte film 13 is small. Therefore, the solid electrolyte membrane 13 is hardly sandwiched between the end surface 15d of the housing 15 and the substrate F. Therefore, in this case, damage to the solid electrolyte film 13 can be reduced, and the metal film F can be stably formed.

Further, since the anode 11 is in contact with the solid electrolyte membrane 13, even if the amount of the metal solution L in the housing 15 is reduced, the surface of the anode 11 facing the solid electrolyte membrane 13 remains. The state of being immersed in the metal solution L can be maintained. As a result, it is possible to suppress the oxidation of the anode 11 and suppress the increase in overvoltage of the anode.

On the other hand, in step S4, if the maximum amount of deflection of the solid electrolyte membrane 13 is larger than the radius of one opening 15a, the process proceeds to step S7. In step S7, the maximum stress acting on the solid electrolyte membrane 13 is calculated from the maximum amount of deflection of the solid electrolyte membrane 13.

Specifically, as shown in the model shown in FIG. 4, the maximum deflection amount wmax of the solid electrolyte film 13 and the maximum stress σmax are the film thickness t of the solid electrolyte film 13, Poisson's ratio ν, the longitudinal elasticity coefficient E, and the solid. It can be calculated by the formulas (1) and (2) when the pressure p of the metal solution L acting on the electrolyte membrane and the radius R of one of the openings 15a are set. In the present embodiment, the pressure p of the metal solution L is calculated from the measured maximum deflection amount wmax and each physical property value using the formula (1), and the calculated pressure p is used to obtain the solid electrolyte membrane 13. The maximum stress σmax is calculated, and the process proceeds to step S8.

In step S8, it is determined whether or not the calculated maximum stress is larger than the tensile breaking strength of the solid electrolyte membrane 13. Here, when the maximum stress calculated in step S8 is not larger than the tensile breaking strength of the solid electrolyte membrane 13, that is, when the calculated maximum stress is equal to or less than the tensile breaking strength of the solid electrolyte membrane 13. Proceed to step S9.

In step S9, the substrate B is placed above and the anode 11 is placed below, sandwiching the solid electrolyte membrane 13. Specifically, the film forming apparatus 1A shown in FIG. 1 is turned upside down. The substrate B is fixed to the base 21 by suction fixing or the like so as not to fall from the base 21. Next, the process proceeds to step S10, in which the anode 11 is arranged below by the same method as in step S6 to form the metal film F.

When the maximum amount of deflection of the solid electrolyte membrane 13 is larger than the radius of one of the openings 15a, the anode 11 is placed above and the substrate B is placed below with the solid electrolyte membrane 13 interposed therebetween, as shown in FIG. When the metal film F is formed, there is a high possibility that the solid electrolyte film 13 is sandwiched between the end face 15d of the housing 15 and the substrate B.

Therefore, if the substrate B is placed above and the anode 11 is placed below the solid electrolyte film 13 in step S9 and the metal film F is formed in step S10, the solid electrolyte film is formed at the time of film formation. The bending of the metal solution L due to its own weight is suppressed. Therefore, it is possible to prevent the solid electrolyte membrane 13 from being sandwiched between the end surface 15d of the housing 15 and the substrate B.

However, when the calculated maximum stress of the solid electrolyte membrane 13 is larger than the tensile breaking strength of the solid electrolyte membrane 13, the weight of the metal solution L is applied to the solid electrolyte membrane 13 when setting the solid electrolyte membrane 13 or the like. If it acts, the solid electrolyte membrane 13 may be damaged.

Therefore, if the maximum stress calculated in step S8 is larger than the tensile breaking strength of the solid electrolyte film 13, the process proceeds to step S11 and the metal film F is not formed. The tensile breaking strength of the solid electrolyte membrane 13 is the stress at which the plastic deformation of the material starts when the same material as the solid electrolyte membrane 13 is subjected to the tensile test.

Below, the confirmation test according to the present invention was confirmed by the reference example shown below.

[Reference Example 1]
First, a metal solution was injected into the housing of the film forming apparatus, and the maximum amount of deflection of the solid electrolyte film was measured. Specifically, as the housing, a cylindrical housing having an outer diameter of 15 cm, an inner diameter of 13 cm, and a height of 50 cm and having a radius of 50 mm at one opening to which the solid electrolyte membrane was attached was used. A solid electrolyte membrane is attached to the end face of the housing so as to cover one of the openings.

Next, in order to measure the amount of deflection of the solid electrolyte membrane, a laser displacement meter (LK-G5000, manufactured by KEYENCE) was installed directly under the cylindrical housing. When measuring the amount of deflection of the solid electrolyte membrane, 1 L of a metal solution for film formation heated to 80 ° C. is injected from the open end face of the cylindrical housing and held for a certain period of time (corresponding to the total film formation time; 1 hour). did. At that time, the end side where the solid electrolyte membrane was not installed was sealed with a resin sheet (manufactured by PTFE), and the metal solution was kept at 80 ° C. with a cord heater to maintain the state.

Before injecting the metal solution and after a certain period of time, a laser displacement meter placed directly under the housing measures the displacement of the solid electrolyte membrane at the center of one of the circular openings, and the maximum amount of deflection of the solid electrolyte membrane is measured from this displacement. Was calculated. The results are shown in Table 1.

Next, using the film forming apparatus according to Reference Example 1, as shown in FIG. 1, the anode is arranged above and the substrate (cathode) is arranged below with the solid electrolyte film interposed therebetween, and FIG. 1 The nickel film was formed by inverting the top and bottom of the film forming apparatus shown in (1), sandwiching the solid electrolyte film, arranging the anode below, and arranging the substrate above.

Specifically, in any of the film formations, a copper sputter substrate was used as the substrate, and a 1M nickel chloride aqueous solution + acetic acid (pH 4.0) solution was used as the metal solution for film formation. The temperature of the metal solution at the time of film formation was maintained at 80 ° C., and the pressing force was 1.0 MPa, and the solid electrolyte film was pressed against the substrate. The film forming area was 10 mm × 10 mm, the current density was 100 mA / cm, and electricity was applied until the thickness of the metal film became 4 μm. The film-forming region was formed by forming a 10 × 10 mm square opening on the substrate with a polyimide tape (Capton adhesive tape: 650R # 25, manufactured by Teraoka Seisakusho Co., Ltd.). The solid electrolyte membrane was prepared by a method according to Japanese Patent No. 3369569. As shown in Table 1, in each case, a nickel film could be formed on the surface of the substrate.

[Reference Examples 2 to 6]
In Reference Examples 2 to 6, as in the confirmation test 1, as shown in FIG. 1, the anode is arranged above and the substrate is arranged below, and the anode is arranged below and the substrate is arranged above. In some cases, a nickel film was formed. The difference between Reference Examples 2 to 6 from Reference Example 1 is the film thickness of the solid electrolyte membrane, and the film thickness of the solid electrolyte membrane becomes thinner in the order of Reference Examples 2 to 6.

In Reference Examples 2 to 4, as shown in Table 1, the maximum amount of deflection of the solid electrolyte membrane is 50 mm or less in radius of one opening. In this case, the anode is arranged above and the substrate is placed below. A nickel film could be formed in both the case where the anode was arranged below and the case where the substrate was arranged above.

In Reference Example 5, as shown in Table 1, the maximum amount of deflection of the solid electrolyte membrane is larger than the radius of 50 mm of one opening. In this case, when the anode was arranged above and the substrate was arranged below, the nickel film could not be formed. However, when the anode was arranged below and the substrate was arranged above, a nickel film could be formed.

In Reference Example 6, as shown in Table 1, the maximum amount of deflection of the solid electrolyte membrane is larger than the radius of 50 mm of one opening. In this case, the nickel film could not be formed either when the anode was arranged above and the substrate was arranged below or when the anode was arranged below and the substrate was arranged above. ..

When the maximum amount of deflection of the solid electrolyte membrane is larger than the radius of one opening of the housing as in Reference Example 5 and Reference Example 6, the anode is placed above and the cathode is placed below to form the metal film. When the anode and the substrate are brought close to each other during the film formation, the solid electrolyte film bent in the vertical direction protrudes from one opening of the housing. As a result, the end face of the housing crushes the solid electrolyte membrane. A load is applied to the crushed portion of the solid electrolyte membrane in one direction, and as a result, stress acts in one direction of the solid electrolyte membrane. As a result, it was found that the voids and cracks inherent in the solid electrolyte film grow in the direction perpendicular to the tensile direction, and the solid electrolyte film breaks during the film formation, so that the film cannot be formed.

However, when the anode is arranged below and the cathode is arranged above to form a metal film, the solid electrolyte film does not bend in the vertical direction due to the weight of the metal solution. It does not protrude from one opening of the housing. Therefore, since the solid electrolyte film on which the end face of the housing protrudes is not crushed, a metal film can be formed as in Reference Example 5.

However, in Reference Example 6, even if the anode was arranged below and the cathode was arranged above to form a metal film, the metal film could not be formed. It is considered that this is because the solid electrolyte film was damaged when the anode was arranged above and the cathode was arranged above to form a film.

Therefore, when the tensile breaking strength of Reference Example 6 was measured in a measurement environment (80 ° C., RH = 95%) based on JIS 7127, it was found to be 9.0 N / mm ² in both the MD direction and the rear of the TD. rice field. The thickness t of the solid electrolyte membrane of Reference Example 6 is 0.05 mm, the radius R of one opening is 50 mm, the Young's modulus E is 400 N / mm ² , the Poisson's ratio ν is 0.25, and the maximum deflection wmax is 280.0 mm. Therefore, the pressure p0.0000127N / mm ² was calculated and the maximum stress σmax9.5N / mm ² was calculated by the equations (1) and (2) shown in FIG.

Therefore, in Reference Example 6, the maximum stress σmax calculated from the maximum deflection wmax is larger than the tensile breaking strength of the solid electrolyte membrane. Therefore, it is suggested that the nickel film cannot be formed even when the anode is installed above and the cathode is installed below, and even when the anode is installed at the bottom and the cathode is installed at the top, and the nickel film of Reference Example 6 is formed. Consistent with the result that the membrane could not be formed.

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 designs are designed without departing from the spirit of the present invention described in the claims. You can make changes.

1A: film forming apparatus, 8: laser displacement meter, 13: solid electrolyte membrane, 15: housing, 15a, 15b: opening, B: substrate, F: metal film, L: metal solution

Claims (1)

A solid electrolyte membrane is placed between the anode and the substrate that is the cathode,
A metal solution containing metal ions is placed so as to be in contact with the anode and the solid electrolyte membrane.
By applying a voltage between the anode and the substrate in a state where the solid electrolyte membrane is in contact with the surface of the substrate, the metal ions contained in the solid electrolyte membrane are reduced to the surface of the substrate. A method for forming a metal film, which is a method for forming a metal film.
In the method for forming a metal film, the solid electrolyte film is formed so that one of the circular openings among the openings at both ends of the tubular housing in which the metal solution is accommodated is covered with the solid electrolyte film. Is fixed to the end face of the housing, and the metal film is formed.
Before forming the metal film, the one opening of the housing is turned downward, and the metal solution adjusted to the temperature conditions at the time of forming the metal film is injected into the housing through the other opening. Then, using a laser displacement meter, the maximum amount of deflection of the solid electrolyte membrane located at the center of the one opening is measured.
When the maximum amount of deflection is equal to or less than the radius of one of the openings, the anode is placed above the solid electrolyte membrane and the substrate is placed below to form the metal film. ,
When the maximum amount of deflection is larger than the radius of one of the openings, the maximum stress acting on the solid electrolyte membrane is calculated from the maximum amount of deflection.
When the maximum stress is equal to or less than the tensile breaking strength of the solid electrolyte membrane, the substrate is placed above the solid electrolyte membrane and the anode is placed below the solid electrolyte membrane to form the metal film. Membrane and
A method for forming a metal film, wherein the metal film is not formed when the maximum stress is larger than the tensile breaking strength of the solid electrolyte film.

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