The present application claims priority from Japanese patent application JP 2020-155163 filed on Sep. 16, 2020, the entire content of which is hereby incorporated by reference into this application.
The present disclosure relates to a film formation device and a film formation method for a metallic coating, and especially relates to a film formation device and a film formation method for a metallic coating that allow forming the metallic coating on a surface of a substrate.
Conventionally, there has been known a film formation device and a film formation method in which metal ions are deposited to form a metallic coating. For example, JP 2014-51701 A proposes a film formation device and a metallic coating method using the device. The film formation device includes an anode, a solid electrolyte membrane disposed between the anode and a substrate that serves as a cathode, a power supply device that applies a voltage between the anode and the cathode, a solution container that contains a solution containing metal ions between the anode and the solid electrolyte membrane, and a pressure device that pressurizes the solid electrolyte membrane to the cathode side with a fluid pressure of the solution. The solid electrolyte membrane is disposed to seal an opening in the cathode side of the solution container.
When a metallic coating is formed on a surface of a substrate by this film formation method for the metallic coating, the solid electrolyte membrane is brought in contact with the surface of the substrate, and subsequently, the metal ions internally contained in the solid electrolyte membrane are deposited by applying a voltage while pressurizing the surface of the substrate by the solid electrolyte membrane with a fluid pressure of a solution, thus forming the metallic coating on the surface of the substrate.
In the conventional film formation device and film formation method for the metallic coating, when the metallic coating is formed on the surface of the substrate, lines of electric force from the anode are locally concentrated in a peripheral edge portion of a film formation region in the surface of the substrate, and a current is concentrated on the peripheral edge portion of the film formation region, thus possibly causing current density variations in the film formation region. Consequently, the metal ions are excessively deposited in the peripheral edge portion of the film formation region in the surface of the substrate, and a film thickness of the metallic coating increases, thereby possibly failing to form the metallic coating with a uniform film thickness.
The present disclosure has been made in consideration of such a situation and provides a film formation device and a film formation method for a metallic coating that allow forming the metallic coating with a uniform film thickness.
To solve the above-described problem, a film formation device for a metallic coating of the present disclosure comprises an anode, a solid electrolyte membrane, a power supply device, a solution container, and a pressure device. The solid electrolyte membrane is disposed between the anode and a substrate that serves as a cathode. The power supply device applies a voltage between the anode and the cathode. The solution container contains a solution between the anode and the solid electrolyte membrane. The solution contains metal ions. The pressure device pressurizes the solid electrolyte membrane to the cathode side with a fluid pressure of the solution. A metallic coating is formed on a surface of the substrate by applying the voltage while pressurizing the surface of the substrate by the solid electrolyte membrane to deposit the metal ions internally contained in the solid electrolyte membrane. The film formation device for the metallic coating further comprises a shielding member disposed to surround an outer peripheral surface of the anode. The shielding member shields a line of electric force.
With the film formation device for the metallic coating of the present disclosure, the metallic coating can be formed with a uniform film thickness.
Furthermore, a film formation method for a metallic coating of the present disclosure is a film formation method for a metallic coating. The film formation method comprises: disposing a solid electrolyte membrane between an anode and a substrate that serves as a cathode; forming a metallic coating on a surface of the substrate by applying a voltage between the anode and the cathode while pressurizing the surface of the substrate by the solid electrolyte membrane with a fluid pressure of a solution to deposit metal ions internally contained in the solid electrolyte membrane, the solution is disposed between the anode and the solid electrolyte membrane, and the solution contains the metal ions; and forming the metallic coating by applying the voltage in a state where a shielding member is disposed to surround an outer peripheral surface of the anode, and the shielding member shields a line of electric force.
With the film formation method for the metallic coating of the present disclosure, the metallic coating can be formed with the uniform film thickness.
With the present disclosure, the metallic coating can be formed with the uniform film thickness.
The following describes embodiments of a film formation device and a film formation method for a metallic coating according to the present disclosure.
First, the embodiment will be schematically described with a film formation device and a film formation method for a metallic coating according to a first embodiment as an example.
As illustrated in
The anode 2 is disposed on an upper surface 12a inside the solution container 12, contained in the solution container 12 so as to be in contact with the metal ion solution L, and electrically connected to the power supply device 8. The anode 2 has a surface 2s parallel to an end surface 6s in the cathode side of the solid electrolyte membrane 6. Since the substrate 4 is embedded in a groove portion 20h of a pedestal 20, the surface 4s of the substrate 4 is disposed on the same plane as a surface 20s of the pedestal 20. The substrate 4 is electrically connected to the power supply device 8. The whole of the surface 4s of the substrate 4 constitutes a film formation region 4r. A shape of the anode 2 in plan view is similar to a rectangle of a shape of the film formation region 4r in plan view as illustrated in
As illustrated in
In the film formation device 1 for the metallic coating, as illustrated in
Furthermore, in the film formation device 1 for the metallic coating, a moving apparatus 52 is connected to an upper portion of the solution container 12. The moving apparatus 52 moves the solution container 12 together with the solid electrolyte membrane 6 toward the substrate 4, thereby bringing the solid electrolyte membrane 6 into contact with the film formation region 4r in the surface 4s of the substrate 4. The moving apparatus 52 is electrically connected to the control device 50, and can receive control signal from the control device 50 to control the operation.
A pressure gauge 54 that measures the fluid pressure of the metal ion solution L contained in the closed space inside the solution container 12 is disposed. The pressure gauge 54 is electrically connected to the control device 50, and can output a fluid pressure value of the metal ion solution L measured by the pressure gauge 54 as a signal.
The control device 50 is electrically connected to the power supply device 8, the pump 30b and the open/close valve 40b, the moving apparatus 52, and the pressure gauge 54. The control device 50 can output control signal to control the power supply device 8, the pump 30b and the open/close valve 40b, and the moving apparatus 52, and can receive the fluid pressure value output as the signal from the pressure gauge 54.
In the film formation method for the metallic coating according to the first embodiment, the film formation device 1 for the metallic coating is used to form a metallic coating M on the film formation region 4r in the surface 4s of the substrate 4. The following describes the process.
First, as illustrated in
Next, inputting control signal from the control device 50 drives the moving apparatus 52, thereby moving the solid electrolyte membrane 6 together with the solution container 12 toward the substrate 4 as illustrated in
Next, inputting control signal from the control device 50 closes the open/close valve 40b, thereby making the inside of the solution container 12 the closed space to contain the metal ion solution L. Subsequently, in this state, inputting control signal from the control device 50 drives the pump 30b, thereby supplying the metal ion solution L to the closed space from the solution tank 30 via the supply pipe 30a, thus controlling the fluid pressure, which is measured by the pressure gauge 54, of the metal ion solution L contained in the closed space to a desired value. Furthermore, inputting control signal from the control device 50 controls the power supply device 8, thereby applying a voltage between the anode 2 and the substrate 4, thus controlling the voltage to a desired value. Thus, as illustrated in
Therefore, according to the film formation device and the film formation method for the metallic coating of the first embodiment, the lines of electric force from the anode 2 are shielded by the shielding member 14 by applying the voltage between the anode 2 and the substrate 4 in a state where the shielding member 14 for shielding the lines of electric force is disposed to surround the outer peripheral surface 2p of the anode 2, thereby allowing suppressing concentration of the current to the peripheral edge portion of the film formation region 4r in the surface 4s of the substrate 4. Accordingly, since the current density variation in the film formation region 4r in the surface 4s of the substrate 4 can be suppressed, the metallic coating M can be formed with a uniform film thickness. Furthermore, the shielding member 14 extending to the cathode side with respect to the anode 2 allows effectively shielding the lines of electric force. Since the end surface in the cathode side of the shielding member 14 is opposed to the peripheral edge portion of the film formation region 4r in the surface 4s of the substrate 4 when the voltage is applied, the concentration of the current to the peripheral edge portion of the film formation region 4r in the surface 4s of the substrate 4 can be easily suppressed by shielding the lines of electric force by the shielding member 14. Subsequently, a description will be given of the configurations of the film formation device and the film formation method for the metallic coating according to the embodiment in detail.
1. Shielding Member
The shielding member is disposed to surround the outer peripheral surface of the anode, and shields the lines of electric force.
Like the shielding member according to the first embodiment, the shielding member extends in the cathode side with respect to the anode in some embodiments. This is because the lines of electric force can be effectively shielded.
While the shape and the size of the shielding member in plan view are not specifically limited, usually, they correspond to the shape and the size of the anode in plan view. Therefore, the shape of the shielding member in plan view is a rectangular frame shape when the shape of the anode in plan view is a rectangular shape as the first embodiment, and is a doughnut shape when the shape of the anode in plan view is a circular shape. While the shape and the size of the opening of the shielding member in plan view are not specifically limited, usually, they are the same as those of the anode.
While the material of the shielding member is not specifically limited insofar as it is an insulator that can shield the lines of electric force, the material of the shielding member has a chemical resistance to the solution containing the metal ions in some embodiments. The material of the shielding member is polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), polyvinyl chloride (PVC), polypropylene (PP), or the like in some embodiments. This is because the lines of electric force can be effectively shielded and the chemical resistance is high. While the thickness of the shielding member is not specifically limited insofar as the thickness is enough to shield the lines of electric force, the thickness is, for example, about a few mm in some embodiments.
2. Anode
While the anode is not specifically limited, for example, the anode has the chemical resistance to the solution containing the metal ions and has a conductivity enough to act as the anode.
While the shape of the anode is not specifically limited, the surface of the anode is parallel to the end surface in the cathode side of the solid electrolyte membrane as the anode according to the first embodiment in some embodiments. While the shape and the size of the anode in plan view are not specifically limited, usually, they correspond to the shape and the size of the film formation region in the surface of the substrate in plan view. This is because the lines of electric force from the anode toward the film formation region can be made uniform, thus allowing formation of the metallic coating excellent in uniformity of the film thickness. The shape and the size include the shape in plan view similar to the film formation region in the surface of the substrate and the size in plan view smaller or larger than the film formation region in the surface of the substrate as the anode according to the first embodiment, the shape and the size in plan view which are the same as those of the film formation region in the surface of the substrate, and the like.
While the material of the anode is not specifically limited, the material of the anode includes a metal having a low ionization tendency compared with the metal of the metal ions (high standard electrode potential compared with the metal of the metal ions), a metal more precious than the metal of the metal ions, and the like. This metal includes, for example, gold.
3. Solid Electrolyte Membrane
The solid electrolyte membrane is disposed between the anode and the substrate that serves as the cathode.
The solid electrolyte membrane contains a solid electrolyte. The solid electrolyte membrane internally contains the metal ions by the contact with the solution containing the metal ions, and the metal ions internally contained in the solid electrolyte membrane are deposited on the surface of the substrate by applying the voltage between the anode and the cathode. While the solid electrolyte membrane is not specifically limited insofar as it is one as described above, the solid electrolyte membrane includes a fluorine-based resin, such as Nafion (registered trademark) manufactured by DuPont, a hydrocarbon resin, a polyamic acid membrane, a membrane with ion exchange function, such as Selemion (CMV, CMD, CMF, and the like) manufactured by AGC Inc., and the like.
4. Solution Container
The solution container contains the solution containing the metal ions (hereinafter referred to as a “metal ion solution” in some cases) between the anode and the solid electrolyte membrane.
While the material of the solution container is not specifically limited insofar as the metal ion solution can be contained between the anode and the solid electrolyte membrane, the material of the solution container has the chemical resistance to the metal ion solution and can shield the lines of electric force in some embodiments.
The metal ion solution is a solution that contains the metal contained in the metallic coating in the state of the metal ions. While the metal of the metal ions is not specifically limited, copper, nickel, silver, gold, and the like are included. The metal ion solution is obtained by dissolving the metal of the metal ions with an acid, such as nitric acid, phosphoric acid, succinic acid, nickel sulfate, and pyrophosphoric acid.
5. Others
The power supply device (power supply unit) applies the voltage between the anode and the cathode. The pressure device (pressurizing unit) pressurizes the solid electrolyte membrane to the cathode side with the fluid pressure of the solution.
While the pressure device is not specifically limited, the pressure device includes, for example, a pump that supplies the metal ion solution to the inside of the solution container, adjusts the fluid pressure of the metal ion solution inside the solution container, and pressurizes the solid electrolyte membrane to the cathode side with the fluid pressure of the metal ion solution, as the pressure device according to the first embodiment.
6. Film Formation Device for Metallic Coating
The film formation device for the metallic coating deposits the metal ions internally contained in the solid electrolyte membrane by applying the voltage while pressurizing the surface of the substrate by the solid electrolyte membrane, thereby forming the metallic coating on the surface of the substrate.
The film formation device for the metallic coating may cause the end surface in the cathode side of the shielding member to be opposed to the peripheral edge portion of the film formation region in the surface of the substrate when the voltage is applied as the film formation device for the metallic coating according to the first embodiment. This is because shielding the lines of electric force by the shielding member allows easily suppressing the concentration of the current to the peripheral edge portion of the film formation region in the surface of the substrate.
Here, the “film formation region in the surface of the substrate” means a region in which the metallic coating is formed in the surface of the substrate. The film formation region in the surface of the substrate may be the entire surface of the substrate as the first embodiment, or may be a part of the surface of the substrate.
Here,
The film formation device for the metallic coating may have the shielding member reduction width W<0 without causing the end surface 14s in the cathode side of the shielding member 14 to be opposed to the peripheral edge portion of the film formation region 4r in the surface 4s of the substrate 4 when the voltage is applied as illustrated in
In the film formation device for the metallic coating, the shielding member gap D is appropriately set as well as the shielding member reduction width W, thereby allowing controlling the shielding action of the lines of electric force by the shielding member. The “shielding member gap D” means a distance from the end surface 14s in the cathode side of the shielding member 14 to the end surface 6s in the cathode side of the solid electrolyte membrane 6 as illustrated in
Here, a description will be given of an analysis result of the current density in the film formation region when the voltage is applied between the anode and the cathode in the case where the sizes of the anode 2 and the opening 14h of the shielding member 14 in plan view and the length of the shielding member 14 extending toward the cathode side are adjusted to change the ratios of the reduction width W and the gap D of the shielding member 14 in the film formation device 1 for the metallic coating according to the first embodiment. In the analysis, Abaqus manufactured by Dassault Systèmes S.E. was used as analysis software. A proportion of the shielding member reduction width W to a distance from the center to the peripheral edge of the film formation region in an evaluation direction parallel to the long side was defined as the ratio of the reduction width W, and a proportion of the shielding member gap D to this distance was defined as the ratio of the gap D. In the cases where the ratio of the shielding member reduction width W and the ratio of the shielding member gap D were set to respective values, the current densities at respective positions in the film formation region were calculated, thus obtaining a current density distribution in the film formation region.
From the result of the analysis described above, a description will be given of the calculation result of the current density variation in the cases where the ratio of the shielding member reduction width W and the ratio of the shielding member gap D were set to the respective values. In this calculation, the maximum value and the minimum value of the current density from the center to the peripheral edge in the evaluation direction as illustrated in
The film formation device for the metallic coating may have a combination of the ratio of the shielding member reduction width W and the ratio of the shielding member gap D in a range having the coordinates of (−2, 0), (−2, 5), (2, 16), (5, 16), (5, 12), and (0, 0) illustrated in
7. Film Formation Method for Metallic Coating
The film formation method for the metallic coating is a film formation method for a metallic coating that includes: disposing a solid electrolyte membrane between an anode and a substrate that serves as a cathode, and forming a metallic coating on a surface of the substrate by applying a voltage between the anode and the cathode while pressurizing the surface of the substrate by the solid electrolyte membrane with a fluid pressure of a solution to deposit metal ions internally contained in the solid electrolyte membrane. The solution is disposed between the anode and the solid electrolyte membrane, and the solution contains the metal ions. The film formation method forms the metallic coating by applying the voltage in a state where a shielding member is disposed to surround an outer peripheral surface of the anode. The shielding member shields lines of electric force.
The film formation method for the metallic coating may be a method in which the shielding member extends toward the cathode side with respect to the anode as the film formation method for the metallic coating according to the first embodiment. This is because the lines of electric force can be effectively shielded. The film formation method for the metallic coating may be a method in which an end surface in the cathode side of the shielding member is opposed to a peripheral edge portion of a film formation region in the surface of the substrate when the voltage is applied as the film formation method for the metallic coating according to the first embodiment. This is because shielding the lines of electric force by the shielding member allows easily suppressing the concentration of the current to the peripheral edge portion of the film formation region in the surface of the substrate.
Here, a film formation method for a wiring pattern as a film formation method for a metallic coating according to a third embodiment will be described in comparison with a conventional technique.
In the film formation method for the wiring pattern according to the conventional technique, as illustrated in
In contrast, in the film formation method for the wiring pattern according to the third embodiment, when a copper coating (metallic coating, not illustrated) is formed on the film formation region 4r in the surface 4s of the similar substrate 4 with the seed layer, as illustrated in
While the substrate that serves as the cathode is not specifically limited insofar as it serves as the cathode and the metallic coating can be formed on the surface of the substrate, the substrate that serves as the cathode includes a substrate with a wiring pattern in which the wiring pattern is disposed on a surface of an insulating substrate, such as the substrate with the seed layer according to the third embodiment, in addition to, for example, a substrate formed of a metal, such as aluminum, and a substrate in which a metal base layer is disposed on a treated surface of a resin substrate, a silicon substrate, or the like. According to the embodiment, when the metallic coating is formed on the surface of the wiring pattern of the substrate with the wiring pattern, the concentration of the current on the wiring in the peripheral edge portion of the film formation region can be suppressed, thus allowing formation of the wiring pattern including a plurality of wirings in which the metallic coating is formed with the uniform film thickness.
When the film formation method for the metallic coating is used, for example, the metallic coating can be formed using the film formation device for the metallic coating according to the embodiment.
While the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited thereto, and can be subjected to various kinds of changes in design without departing from the spirit of the present disclosure described in the claims.
All publications, patents and patent applications cited in the present description are herein incorporated by reference as they are.
Number | Date | Country | Kind |
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JP2020-155163 | Sep 2020 | JP | national |
Number | Name | Date | Kind |
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8623193 | Mayer | Jan 2014 | B1 |
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2014-051701 | Mar 2014 | JP |
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20220081797 A1 | Mar 2022 | US |