Metal ion supply system for electroplating apparatus and method for supplying metal ions to electroplating apparatus

Abstract

To provide a metal ion supply system that suppresses dilution of the plating solution in the plating solution circulation chamber. [Solution] A metal ion supply system comprising an anode chamber, an anode installed in the anode chamber, a cathode chamber, a cathode installed in the cathode chamber, a plating solution circulation chamber positioned between the anode chamber and the cathode chamber, a first diaphragm positioned between the anode chamber and the plating solution circulation chamber, and a second diaphragm positioned between the cathode chamber and the plating solution circulation chamber, wherein the plating solution circulation chamber has an outlet for discharging the plating solution to an electrolytic plating apparatus so that the plating solution can be circulated, and an inlet for receiving the plating solution from the electrolytic plating apparatus, the second diaphragm has a water diffusion and penetration rate greater than that of the first diaphragm, the anode chamber is filled with anolite containing ions of the same metal as the metal contained in the anode, and the cathode chamber is filled with catholite, the catholite having a higher osmolality than the osmolality of the plating solution in the plating solution circulation chamber.

Description

[Technical Field]

[0001] The present invention relates to a metal ion supply system for an electroplating apparatus and a method for supplying metal ions to an electroplating apparatus. [Background technology]

[0002] When applying various platings such as Cu, Sn, SnAg alloy, and Ni to the surface of structures such as metal plates and substrates, an electrolytic plating apparatus equipped with a plating tank containing a plating solution is used. The metal ions (Cu) contained in the plating solution 2+ Sn 2+ These substances (etc.) are consumed during the plating process, so it is necessary to replenish the metal ions in the plating solution within the plating tank.

[0003] Patent Document 1 discloses a metal concentration cell having an anode region and a cathode region as a device for supplying metal ions to the plating solution in a plating tank. In Patent Document 1, metal ions are supplied to the plating solution in the plating tank by circulating the plating solution between the metal concentration cell and the plating tank of the electroplating apparatus. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] U.S. Patent No. 9637836 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] When using a metal ion supply system with a three-chamber cell structure (anode chamber / plating solution circulation chamber / cathode chamber) separated by two types of diaphragms, as described in Patent Document 1, metal ions are sometimes supplied from the anode chamber to the plating solution in the plating solution circulation chamber. In this case, when metal ions electroosmotically move from the anode chamber to the plating solution circulation chamber through the diaphragm, water also moves along with them. On the other hand, electroosmotic movement of hydrogen ions from the plating solution circulation chamber to the cathode chamber also occurs through the diaphragm, and water also moves along with the hydrogen ions during this electroosmotic movement. The inventors of this invention have conducted extensive research on the above-mentioned metal ion supply system and have found that the amount of water transferred during the electroosmosis of metal ions is greater than the amount of water transferred during the electroosmosis of hydrogen ions, which can dilute the plating solution in the plating solution circulation chamber. Normally, electroplating equipment maintains a constant concentration of the plating solution by supplying water equivalent to the amount of plating solution lost due to evaporation, etc. However, if an excessive amount of water is supplied to the plating solution in the plating solution circulation chamber due to the difference in the amount of water transferred as described above, the plating solution will be diluted. When diluted plating solution is supplied to the electroplating equipment, the concentration of the plating solution in the electroplating equipment is gradually diluted, which is undesirable. In particular, to improve the production capacity of the plating equipment, it is necessary to increase the amount of metal ions supplied. In this case, the amount of water transferred during electroosmosis into the plating solution circulation chamber tends to be greater than the amount of plating solution evaporated, which is a particular problem.

[0006] In view of these circumstances, the first objective of the present invention is to provide a metal ion supply system that suppresses the dilution of the plating solution in the plating solution circulation chamber.

[0007] Furthermore, when using a metal ion supply system with a three-chamber cell structure (anode chamber / plating solution circulation chamber / cathode chamber) separated by two types of diaphragms, as described in Patent Document 1, the operation of the electroplating apparatus may be stopped for maintenance or other reasons. The inventors of the present invention have diligently conducted research on the above metal ion supply system, and have found the above It has been found that during shutdown of an electroplating apparatus, cation exchange can occur via diffusion between the anode chamber and the plating solution circulation chamber across a diaphragm, potentially causing metal ions from the plating solution in the circulation chamber to enter the anode chamber. If the ionization tendency of the metal ions introduced into the anode chamber is lower than that of the anode, a substitution reaction occurs on the anode surface, resulting in the deposition of metal originating from the introduced metal ions. When this metal is deposited on the anode surface, the anode surface becomes passivated, inhibiting electrolysis in the metal ion supply system. For example, Ag (silver ions) may be present as metal ions in the plating solution. + When Sn is used as an ion and anode, Ag in the plating solution + When ions enter the anode chamber, the ionization tendency of Sn is greater than that of Ag, which can lead to the following reaction and passivation of the anode surface.

[0008] [ka]

[0009] In view of these circumstances, the second objective of the present invention is to provide a method for supplying metal ions that suppresses passivation of the anode surface caused by metal ions introduced from within the plating solution circulation chamber.

[0010] Furthermore, in a metal ion supply system using a three-chamber cell structure (anode chamber / plating solution circulation chamber / cathode chamber) separated by two types of diaphragms, as described in Patent Document 1, a soluble anode may be installed in the anode chamber, and metal ions may be supplied from the soluble anode to the anolite by electrolysis.

[0011] As electrolysis progresses, hydrogen ions (H) contained in the anolite in the anode chamber + As the metal ions pass through the diaphragm and move into the plating solution circulation chamber, the hydrogen ion concentration in the anolite decreases and the pH increases. When the pH rises, sludge originating from these metal ions may be generated in the anolite or on the diaphragm adjacent to the anode chamber. For example, if the metal contained in the soluble anode is Sn, 2+ When supplying to anolite, if the pH of the anolite is above a certain value, the following reaction may occur, generating the sludge Sn(OH)2.

[0012] [ka]

[0013] Since sludge formation inhibits the electrolytic reaction, it is desirable to suppress sludge formation. Such sludge often has low solubility in the neutral range, and in order to stably dissolve metal ions in the anorite, it is necessary to maintain the pH of the anorite in the anode chamber below a certain value.

[0014] One method to prevent sludge formation is to periodically discharge a portion of the anolite and add an acid such as MSA (methanesulfonic acid) to the anolite. However, this method involves the discharge of a portion of the anolite, which can introduce metal ions (Sn 2+ Some of the other materials (such as anolite) are also discharged at the same time, leading to increased costs. Furthermore, the need to manage anolite becomes cumbersome.

[0015] Another method to prevent sludge formation is to install an additional insoluble anode in the anode chamber and control it with a separate power supply. However, this method involves another The added power supply control will lead to increased costs.

[0016] In view of these circumstances, the third objective of the present invention is to provide a metal ion supply system that suppresses the generation of sludge in the anolite and diaphragm within the anode chamber. [Means for solving the problem]

[0017] As a result of diligent research to achieve the above-mentioned problems, the inventors have found that at least part of the above-mentioned problems can be solved by the following configuration.

[0018] [1] A metal ion supply system for an electroplating apparatus, Anode chamber, Anode installed in the aforementioned anode chamber, Cathode chamber, The cathode installed in the aforementioned cathode chamber, A plating solution circulation chamber is located between the anode chamber and the cathode chamber. A first diaphragm is disposed between the anode chamber and the plating solution circulation chamber, and A second diaphragm is positioned between the cathode chamber and the plating solution circulation chamber. Equipped with, The plating solution circulation chamber includes an outlet for discharging the plating solution to an electrolytic plating apparatus and an inlet for receiving the plating solution from the electrolytic plating apparatus, so that the plating solution can be circulated. The second diaphragm has a water diffusion and permeation rate that is greater than the water diffusion and permeation rate of the first diaphragm. The anode chamber is filled with an anolite containing ions of the same metal as the metal contained in the anode. The cathode chamber is filled with catholite. The metal ion supply system wherein the catholite has a higher osmolality than the osmolality of the plating solution in the plating solution circulation chamber. [2] The metal ion supply system according to [1], wherein the anode is a soluble anode. [3] The metal ion supply system according to [1] or [2], wherein the first diaphragm is a cation exchange membrane and the second diaphragm is a hydrogen ion selective permeable membrane or a bipolar membrane. [4] A method for supplying metal ions to an electroplating apparatus, (i) A step of circulating a plating solution containing metal ions between a plating solution circulation chamber and an electrolytic plating apparatus to supply the metal ions to the electrolytic plating apparatus, and (ii) A step in which the metal ions are not supplied to the electroplating apparatus, wherein the plating solution circulation chamber is replaced with a liquid that substantially does not contain at least one of the metal ions. The method for supplying metal ions, including the aforementioned method. [5] The metal ion supply method according to [4], further comprising the step of discharging a liquid in the plating solution circulation chamber that substantially does not contain at least one of the plating solution or the metal ions to an outside other than the electrolytic plating apparatus when switching between step (i) supplying metal ions and step (ii) not supplying metal ions. [6] The metal ion supply method according to [4], further comprising the step of stopping the operation of the plating solution circulation chamber and discharging the liquid in the plating solution circulation chamber that substantially does not contain at least one of the plating solution or the metal ions to an outside other than the electrolytic plating apparatus when switching between step (i) supplying metal ions and step (ii) not supplying metal ions. [7] The metal ion supply method according to any one of [4] to [6], using a metal ion supply system in which the plating solution circulation chamber is located between the anode chamber and the cathode chamber. A method for supplying metal ions according to any one of [4] to [6], performed using the metal ion supply system described in [1]. [9] A metal ion supply system for an electroplating apparatus, An anode chamber containing an anode and filled with anolite, A cathode chamber containing a cathode and filled with catholite, A first plating solution circulation chamber is defined by a first diaphragm and a second diaphragm and is located between the anode chamber and the cathode chamber, and One or more laminated modules disposed between the first plating solution circulation chamber and the cathode, each comprising an anolite chamber filled with anolite and a second plating solution circulation chamber defined by a third diaphragm and a fourth diaphragm, Equipped with, The third diaphragm is made of the same material as the first diaphragm, and the fourth diaphragm is made of the same material as the second diaphragm. The first plating solution circulation chamber and the second plating solution circulation chamber each include an outlet for discharging the plating solution to an electrolytic plating apparatus and an inlet for receiving the plating solution from the electrolytic plating apparatus, respectively, so that the plating solution can be circulated. The metal ion supply system comprises an anorite chamber having an outlet for discharging anorite from the anorite chamber and an inlet for receiving anorite into the anorite chamber, so as to enable fluid communication between the anorite in the anode chamber and the anorite in the anorite chamber.

[10] The metal ion supply system according to [9], wherein the first and third diaphragms are cation exchange membranes, and the second and fourth diaphragms are hydrogen ion selective permeable membranes or bipolar membranes. [Effects of the Invention]

[0019] According to a first embodiment of the present invention, a metal ion supply system is provided that suppresses the dilution of the plating solution in the plating solution circulation chamber. According to a second embodiment of the present invention, a method for supplying metal ions is provided that suppresses passivation of the anode surface caused by metal ions introduced from within the plating solution circulation chamber. According to a third embodiment of the present invention, a metal ion supply system is provided that suppresses the generation of sludge in the anolite and diaphragm within the anode chamber. [Brief explanation of the drawing]

[0020] [Figure 1] This is a cross-sectional view showing the overall configuration of the metal ion supply system. [Figure 2] This is a magnified view of the area around the cathode chamber in a metal ion supply system. [Figure 3] This is a cross-sectional view showing the cell structure of a metal ion supply system. [Figure 4] This is a schematic side view showing the configuration of the plating tank. [Figure 5] This diagram shows the overall process of the metal ion supply method. [Figure 6] This is a cross-sectional view showing the overall configuration of the metal ion supply system. [Figure 7] This is a cross-sectional view showing the movement of ions in a metal ion supply system. [Figure 8] This is a photograph of the three-chamber cell used in the example. [Figure 9] This graph shows the change in the amount (moles) of Cu in the anolite, plating solution, or catholite during the test. [Figure 10] This graph shows the changes in the volume (in liters) of anolite, plating solution, or cassolite during the test. [Figure 11] This graph shows the change in pH of the anolite during the test. [Figure 12] This is a photograph showing the appearance of the cathode after testing. [Figure 13] This graph shows the change in the concentration (g / L) of Cu2+ or H2SO4 when the concentration of cassolite (H2SO4) is set to 100 g / L. [Figure 14] This graph shows the change in the volume (L) of each solution (anolite, plating solution, and catholite) when the catholite concentration is set to 100 g / L. [Figure 15] This graph shows the change in the concentration (g / L) of Cu2+ or H2SO4 when the concentration of cassolite is set to 230 g / L. [Figure 16] This graph shows the change in the volume (L) of each solution (anolite, plating solution, and catholite) when the catholite concentration is set to 230 g / L. [Figure 17] This graph shows the change in the concentration (g / L) of Cu2+ or H2SO4 when the concentration of cassolite is set to 300 g / L. [Figure 18] This graph shows the change in the volume (L) of each solution (anolite, plating solution, and catholite) when the catholite concentration is set to 300 g / L. [Figure 19] This graph shows the changes in the concentration (g / L) of Cu2+ or H2SO4 in the simulation. [Figure 20]This graph shows the changes in the volume (L) of each solution (anolite, plating solution, catholite) in the simulation. [Figure 21] This is a cross-sectional view of the overall configuration of the 3-chamber cell 2100 and the plating cell (plating tank) 10 used in Test Examples 4-6. [Modes for carrying out the invention]

[0021] The present invention will be described in detail below. The following description of the constituent elements may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, the numerical range expressed using "X~Y" means the range that includes the numerical values ​​represented by X and Y as the lower and upper limits, respectively. Furthermore, in the following explanation, parts having the same function and / or structure may be denoted by the same reference numeral and their explanation may be omitted.

[0022] 1. First Embodiment The metal ion supply system for the electroplating apparatus of the first embodiment is A metal ion supply system for an electroplating apparatus, Anode chamber, Anode installed in the aforementioned anode chamber, Cathode chamber, The cathode installed in the aforementioned cathode chamber, A plating solution circulation chamber is located between the anode chamber and the cathode chamber. A first diaphragm is disposed between the anode chamber and the plating solution circulation chamber, and A second diaphragm is positioned between the cathode chamber and the plating solution circulation chamber. Equipped with, The plating solution circulation chamber includes an outlet for discharging the plating solution to an electrolytic plating apparatus and an inlet for receiving the plating solution from the electrolytic plating apparatus, so that the plating solution can be circulated. The second diaphragm has a water diffusion and permeation rate that is greater than the water diffusion and permeation rate of the first diaphragm. The anode chamber is filled with an anolite containing ions of the same metal as the metal contained in the anode. The cathode chamber is filled with catholite. The catholite has a higher osmolality than the osmolality of the plating solution in the plating solution circulation chamber. In this embodiment, the metal ion supply system can suppress dilution of the plating solution in the plating solution circulation chamber because the catholite has a higher osmolality than the osmolality of the plating solution in the plating solution circulation chamber.

[0023] The following describes one embodiment of the metal ion supply system of this model.

[0024] Figure 1 is a cross-sectional view showing the overall configuration of the metal ion supply system.

[0025] In Figure 1, the metal ion supply system 2000 comprises an anode chamber 1100, a plating solution circulation chamber 1200, and a cathode chamber 1300. A first diaphragm 1400 is positioned between the anode chamber 1100 and the plating solution circulation chamber 1200. A second diaphragm 1500 is positioned between the plating solution circulation chamber 1200 and the cathode chamber 1300. An anode 1600 is installed in the anode chamber 1100, and it is filled with anolite. A cathode 1700 is installed in the cathode chamber 1300, and it is filled with catholite. The plating solution circulation chamber 1200 includes an outlet 1210 for discharging the plating solution to the electroplating apparatus and an inlet 1220 for receiving the plating solution from the electroplating apparatus. As indicated by the arrows, the plating solution is discharged from the plating solution circulation chamber 1200 to the electroplating apparatus and flows back into the plating solution circulation chamber 1200 from the electroplating apparatus. An external power supply 1900 is connected to the anode 1600 and cathode 1700. Furthermore, to agitate the anorite, it is desirable to introduce a gas 1850, such as air, nitrogen, or argon, through a diffuser 1800. If the anorite contains easily oxidizable metal ions such as Sn(II) ions, it is preferable to use an inert gas such as nitrogen or argon as the gas 1850. In addition to or instead of the diffuser 1800, other agitation means such as paddles or jet nozzles can also be used.

[0026] In the metal ion supply system described above, the diffusion and permeation rate of water through the second diaphragm 1500 is greater than that of water through the first diaphragm 1400. For example, it is preferable to use a cation exchange membrane as the first diaphragm and a hydrogen ion selective permeable membrane or a bipolar membrane as the second diaphragm.

[0027] In the metal ion supply system 2000 shown in Figure 1, the following components are used: First diaphragm 1400: fluorine-based cation exchange membrane, second diaphragm 1500: hydrogen ion selective permeable membrane or bipolar membrane, anode 1600: Cu ball, anolyte: CuSO4 solution (partially containing H2SO4) (pH 1.5 to 3.5), cathode 1700: Pt / Ti (Pt-coated lattice-shaped Ti mesh), catholyte: H2SO4 solution

[0028] When a voltage is applied to the anode 1600 and the cathode 1700 by an external power source 1900, the Cu contained in the anode 1600 is ionized, and Cu 2+ becomes and is released into the anolyte. Due to the influence of the potential difference, the Cu released into the anolyte 2+ passes through the first diaphragm 1400, which is a cation exchange membrane, and moves into the plating solution in the plating solution circulation chamber 1200. When 1 mole of Cu 2+ moves into the plating solution, n moles of water also move along with Cu 2+ (movement of water due to electroosmosis accompanying the movement of ions) (in FIG. 1, denoted as "Cu 2+ (H2O) n ").

[0029] Also, due to the influence of the potential difference, the H + existing in the anolyte also passes through the first diaphragm 1400 and moves into the plating solution in the plating solution circulation chamber 1200. When H + moves into the plating solution, water also moves along with H + . In this regard, in the metal ion supply system 2000 of FIG. 1, the pH is adjusted to 1.5 to 3.5 by making the sulfuric acid concentration in the anolyte sufficiently low. Therefore, the amount of H + moving from the anolyte to the plating solution is extremely small compared to the amount of Cu 2+ moving, and the movement of water accompanying H + can be almost ignored.

[0030] The H + existing in the catholyte receives electrons from the cathode 1700, and hydrogen gas (H2) is generated on the surface of the cathode 1700. Due to the influence of electroosmosis, the H + existing in the plating solutionIt moves through the second diaphragm 1500, which is a hydrogen ion selective permeable membrane or a bipolar membrane, to the catholite in the cathode chamber 1300. 1 mole of H + When H moves to the cassolite, + Along with this, millimoles of water also move (water movement by electroosmosis accompanying ion movement) (in Figure 1, "H + (H2O) m (This is written as "). The second diaphragm 1500 is Cu 2+ Due to its low permeability, Cu is unable to enter the catholite from the plating solution. 2 + The amount of movement is extremely small, Cu 2+ It remains in the plating solution.

[0031] In this embodiment, the cassolite has a higher osmolality (total solute concentration) than the osmolality of the plating solution in the plating solution circulation chamber. Therefore, water moves from the plating solution to the cassolite by diffusion and infiltration (indicated as "H2O" in Figure 1, with an arrow extending from the plating solution to the cassolite).

[0032] The plating solution circulation chamber 1200 is connected to the plating tank of the electroplating apparatus, and the plating solution circulates between the plating solution circulation chamber 1200 and the plating tank. As described above, Cu 2+ As it moves in, metal ions such as Cu enter the plating solution in the plating solution circulation chamber 1200. 2+ It is replenished. And Cu in the plating solution 2+ The metal ions are transported from the plating solution circulation chamber 1200 to the plating tank and used as raw materials for the plating process. In this way, by operating the metal ion supply system, the electroplating apparatus can be operated while supplying metal ions to the electroplating apparatus, allowing for continuous plating without stopping the electroplating apparatus.

[0033] Through diligent research conducted by the inventors, it was found that in a metal ion supply system as shown in Figure 1, under normal operating conditions (liquid temperature 20-40°C, membrane current density of approximately 3-6 ASD), Cu 2+The amount of electroosmotic flow (n) of water from the anolite to the plating solution, and H + It was found that the electroosmotic flow rate (m) of water from the plating solution to the catholite, and the molar ratio (n:m) of water, were approximately 8:3. In this case, the amount of water flowing into the plating solution is greater than the amount of water flowing out of the plating solution, resulting in the plating solution being diluted by water. Dilution of the plating solution is undesirable because it alters the composition of the plating solution supplied to the electrolytic plating apparatus.

[0034] The inventors have found that the above problem can be solved by setting the osmolality of the catholite higher than the osmolality of the plating solution in the plating solution circulation chamber 1200. Normally, osmotic pressure is generated by the difference in osmolality, causing water to permeate from the lower concentration side to the higher concentration side. Therefore, by setting the osmolality of the catholite and the plating solution as described above, the movement of water by diffusion permeation from the plating solution to the catholite can be promoted. In this way, by promoting the movement of water by diffusion permeation, excess water present in the plating solution can be released to the catholite, and dilution of the plating solution can be suppressed. In this specification, suppression of dilution of the plating solution means slowing down the progress of dilution of the plating solution or preventing dilution of the plating solution.

[0035] The relationship between osmolality and concentration in the metal ion supply system shown in Figure 1 is explained in more detail below. The chemical equilibrium of each reaction in the metal ion supply system is summarized in Table 1 below.

[0036] [Table 1]

[0037] If the total CuSO4 concentration is Ac and the total H2SO4 concentration is As, then the following equations (1) and (2) hold true.

[0038]

number

[0039] Generally, ions in an electrolyte are electrically neutral, so the following equation (3) holds true.

[0040]

number

[0041] In the above formula (3), [OH - This factor is almost negligible in acidic solutions. Therefore, the osmolality (Osm) can be expressed as follows:

[0042]

number

[0043] From the above formula, if the total CuSO4 concentration, total H2SO4 concentration, and hydrogen ion concentration (pH) in the solution are known, the osmolality can be calculated.

[0044] Equation (3) requires the hydrogen ion concentration (pH), but for example, in copper sulfate plating solutions, if the sulfuric acid concentration exceeds 1 mol / L, the pH will be 0 or less, and measurement may not be possible. If the pH is 0 or less, [HSO4 - Since ] is considered to be almost completely dissociated, we can assume that the following equation holds true.

[0045]

number

[0046] The following describes in more detail each component of the metal ion supply system of this embodiment.

[0047] (Anode chamber) The anode chamber can accommodate anodes and anolites. The capacity (size) of the anode chamber is not particularly limited, and the optimal size can be selected as appropriate depending on the required metal ion supply rate (electrolysis rate per hour) and the size of the anode to be housed. It is preferable that the anode chamber be equipped with a liquid level sensor and connected to a pure water supply line.

[0048] Water can be supplied to the anode chamber via a pure water supply line. By supplying the anode chamber with pure water equivalent to the amount of water that flows out into the plating solution circulation chamber as electroosmotic water through the first diaphragm during electrolysis, and the amount of water lost due to the evaporation of anolite, changes in the anolite concentration can be suppressed.

[0049] (anode) The anode is placed in the anode chamber. It is preferable to use a soluble anode. Alternatively, a combination of a soluble anode and an insoluble anode can be used. By using a combination of a soluble anode and an insoluble anode, the rise in pH of the anolite due to electrolysis can be suppressed compared to when an insoluble anode is not used. Therefore, a decrease in the solubility of the soluble anode can be prevented.

[0050] The metal contained in the anode can be appropriately set depending on the type of metal to be plated. While the metal in the anode is not particularly limited, Cu, Sn, Pb, SnPb, Ni, Ag, or Bi are preferably used. Of these, Cu is particularly preferred. Furthermore, an anode with a small amount of impurities added can be used to improve the anode's solubility or to suppress undesirable reactions with the plating solution components. For example, when applied to copper sulfate plating, a phosphorus-containing copper anode can be suitably used.

[0051] The shape of the anode is not particularly limited, but it can be a sphere (ball), a disc, a slab, a rod, or a cylinder.

[0052] An anode may consist of one or more components. For example, a single plate-shaped (e.g., rectangular or circular) anode may be used, or multiple small pieces of anode (e.g., spherical, granular, or rod-shaped) may be housed in a conductive case. For example, an anode may consist of multiple Cu balls. When multiple small pieces of anode are used, the impact on the electrolytic reaction when the shape and size of the anode change due to consumption is small. Also, when multiple small pieces of anode are housed in a conductive case, it is sufficient to replenish the case with new anodes equivalent to the amount consumed, and there is no need to stop the device to replace the anode. The material of the case for filling the anode should be a metal that does not oxidize or dissolve due to the electrode reaction, and titanium lath mesh or perforated plates can be suitably used. Furthermore, the anode may be housed in an anode bag. Using an anode bag can suppress or prevent sludge generated from the anode from mixing into the anolite. Anode bags can be made of woven or nonwoven fabrics, which are commonly used for anodes. Suitable materials for anode bags include chemical-resistant resin fibers such as polypropylene and polyvinylidene chloride.

[0053] (Anolite) Anolites fill the anode chamber and contain ions of the same metal as the anode. For example, if Cu is used as the anode metal, the anolite will contain Cu ions. 2+ It may contain ions. As for the metal ions contained in such anolite, ions derived from the metals mentioned above in the anode section can be used.

[0054] The metal ions contained in anolite are not particularly limited, but Cu 2+ Sn 2+ , or Ni 2+ It is preferable to use Cu 2+ It can be used with particular preference.

[0055] The inventors conducted tests and found that under normal electrolysis conditions (liquid temperature 20-40°C, membrane current density approximately 3-6 ASD), the amount of electroosmotic water (n moles) from the anorite to the plating solution, accompanied by the aforementioned metal ions contained in the anorite, and H + The relationship between the amount of electroosmosis (m moles) of water from the plating solution to the cassolite and the accompanying process was n > m. This is because, in the case of ordinary metal ions, hydration water moves along with the movement of metal ions, but H + This is thought to be because, even in the Grottus mechanism (proton jump mechanism), electric charge can still move, resulting in a relatively smaller amount of accompanying water movement.

[0056] The anolite may be a solution containing a metal salt. Preferably, the metal salt in the solution is a solution containing the metal salt present in the plating solution used in combination. For example, when used in combination with a copper sulfate plating solution, a CuSO4 solution can be used as the anolite, or when using a plating solution mainly composed of tin methanesulfonate, a tin methanesulfonate solution can be used as the anolite. Of these, a CuSO4 solution is particularly suitable. A general copper sulfate plating solution (VMS) can be used as the anolite.

[0057] The pH of the anolite is not particularly limited, but it is preferable to select a pH range that provides good stability of the metal ions, good solubility of the anode, and a high transport rate of metal ions when they permeate the first membrane, depending on the type of plating solution and the type of metal ions supplied. For example, when using a copper sulfate plating solution, the pH of the anolite is preferably 0.5 to 5, more preferably 1 to 4, and most preferably 1.5 to 3.5. By keeping the pH of the anolite within the above numerical range, it becomes possible to stably supply metal ions with high current efficiency.

[0058] In this embodiment, gas can be blown into the anolite (bubbling) to stir it. This allows for a uniform concentration distribution of the anolite, stabilizes the electrolytic voltage, and suppresses the precipitation of inorganic components.

[0059] The above gas is not particularly limited, but a non-reactive gas, air, or oxygen can be used. Nitrogen, carbon dioxide, or argon can be used as non-reactive gases. When the anolite contains easily oxidizable metal ions such as divalent Sn ions, it is preferable to use a non-reactive gas. Using a non-reactive gas reduces the dissolved oxygen in the anolite, suppressing the oxidation of the metal in the anolite and inhibiting the generation of the precipitate Sn(OH)4.

[0060] When using anolite in combination with a copper sulfate plating solution, and the anode contains copper, it is preferable to use an oxygen-containing gas such as air. By using an oxygen-containing gas, the monovalent Cu ions in the anolite can be oxidized to divalent Cu ions, thereby reducing the concentration of monovalent Cu ions. Reducing the concentration of monovalent Cu ions suppresses the generation of sludge due to the disproportionation reaction of monovalent Cu ions, and also prevents monovalent Cu ions from permeating the diaphragm and mixing into the plating solution, thereby altering the plating solution additives.

[0061] The above gases can be used individually or in combination of two or more. In addition, other stirring methods such as paddle stirring or jet stirring can be used instead of or in addition to the bubbling described above, and multiple stirring methods can also be used in combination.

[0062] (Cathode chamber) The cathode chamber can accommodate the cathode and the cathodeite. The capacity (size) of the cathode chamber is not particularly limited, and the optimal size can be selected as appropriate depending on the required metal ion supply rate (electrolysis rate per hour) and the size of the cathode to be housed.

[0063] The cathode chamber preferably includes level sensors for detecting three levels: the upper limit level of the cassolite liquid level (cassolite upper level), the lower limit level of the cassolite liquid level (cassolite lower level), and the cassolite supply level, as well as a cassolite supply line and a discharge line linked to them. As electrolysis-induced electroosmotic water and osmolar concentration difference between the electroosmotic water and the plating solution are supplied to the cassolite via the second diaphragm, the cassolite is diluted and the liquid level gradually rises. When the liquid level reaches the cassolite upper level, the cassolite is discharged from the discharge port down to the cassolite lower level. After discharge, cassolite is supplied from the cassolite supply line until it reaches the cassolite supply level. The concentration of the cathode ray can be controlled within a certain range. Alternatively, instead of using a level sensor, flow meters can be installed in the cathode ray supply and discharge lines to ensure a fixed amount of cathode ray is supplied and discharged. If a separate reserve tank is installed to circulate the cathode ray between the cathode chamber and the reservoir, the level sensor and supply / discharge lines can also be installed in the reserve tank.

[0064] (Cathode) The cathode is installed in the cathode chamber. The cathode is not particularly limited, but an inert cathode or an insoluble cathode can be used, and an inert and insoluble cathode is particularly useful. By using an inert and insoluble cathode, there is no elution of components into the catholite, and the composition of the catholite can be stabilized.

[0065] The metal contained in the cathode is not particularly limited, but Pt, Ti, Nb, Pt-coated metal, or a combination of two or more of these can be used. Among these, Pt-coated Ti is preferred. When Pt-coated Ti is used, the insoluble Pt coats the Ti surface, resulting in an inert and insoluble cathode, and since metal ions do not leach from the cathode, there is little variation in the composition of the cathode.

[0066] The shape of the cathode is not particularly limited, but it can be a rod, a ball, a disc, or a slab. If the cathode is a disc or a slab, it may have multiple through-holes, such as in a perforated metal plate or expanded metal plate. By having multiple through-holes, the surface area of ​​the cathode can be increased, and the electrolytic voltage can be kept low even at high current densities. The cathode may consist of one or more components.

[0067] (Catholite) The catholite is filled into the cathode chamber. The cassolite is not particularly limited, but it is preferably a solution of an anionic acid that is the main component in the plating solution used in combination. When used in combination with copper sulfate plating solution, a H2SO4 solution of cassolite is preferred. By using a solution of an anionic acid that is the main component in the plating solution, even if a small amount of cassolite enters the plating solution from the diaphragm or seal, the impact on the plating solution can be minimized.

[0068] It is preferable that the catholite substantially does not contain ions of the same metal as the metal contained in the anode. The "metal contained in the anode" above may be the metal described above in the section on anodes. In this specification, "substantially does not contain ions of the same metal as the metal contained in the anode" means that the concentration of ions of the said metal is 0.1 g / L or less.

[0069] In this embodiment, gas can be blown into the catholite (bubbling) to perform stirring. This allows for a uniform concentration distribution of the catholite and a stabilization of the electrolytic voltage. The gas is not particularly limited and the same gas used to stir the anolite described above can be used. The gas can be used alone or in combination of two or more types. In addition to or instead of the above bubbling, other stirring methods such as paddle stirring or jet stirring can be used, and multiple stirring methods can also be used in combination.

[0070] In the metal ion supply system of this embodiment, any one of the following combinations of anode, anolite, cathode, and catholite (1) to (3) can be used. (1) Anode: Cu ball, Anolite: Mixture of copper sulfate and sulfuric acid, Cathode: Pt-coated Ti mesh, Catholite: Sulfuric acid (2) Anode: Sn pellet, Anolite: Mixed solution of tin methanesulfonate and methanesulfonic acid, Cathode: Pt-coated Ti mesh, Catholite: Methanesulfonic acid solution (3) Anode: Ni ball, Anolite: Mixed solution of nickel sulfamate and boric acid, Cathode: Pt coated Ti mesh, Castholite: Sulfamic acid solution

[0071] (Plating solution circulation chamber) The plating solution circulation chamber is located between the anode chamber and the cathode chamber. The plating solution circulation chamber has an outlet for discharging the plating solution to the electroplating apparatus and an inlet for receiving the plating solution from the electroplating apparatus, so that the plating solution can be circulated. The plating solution circulation chamber can contain the plating solution.

[0072] The plating solution circulation chamber may be defined by a first diaphragm and a second diaphragm, as described later. For example, the plating solution circulation chamber may be a cell structure formed by a gasket or spacer sandwiched between a first diaphragm and a second diaphragm, which are supported by a frame. Alternatively, the plating solution circulation chamber may have a structure in which an anode chamber with a first diaphragm positioned at its opening and a cathode chamber with a second diaphragm positioned at its opening are arranged so that the two diaphragms face each other and are installed at a certain distance from each other.

[0073] The capacity of the plating solution circulation chamber is not particularly limited, and an appropriate capacity can be selected according to the required metal ion supply rate (electrolysis rate per unit time). In particular, the above-described cell structure of the plating solution circulation chamber is preferable because it allows the width of the plating solution circulation chamber to be reduced to about 1 mm, thereby reducing the capacity of the plating solution circulation chamber.

[0074] In this embodiment, the volume of the plating solution circulation chamber can be reduced, thereby reducing the amount of plating solution remaining in the chamber. This reduces the amount of metal ions that enter the anode chamber from the plating solution circulation chamber, and as a result, the passivation of the anode surface described above can be further suppressed. For example, the volume of the plating solution circulation chamber can be reduced by reducing the distance between the first diaphragm and the second diaphragm. In such a case, the volume of the plating solution circulation chamber can be set to 0.1 to 5 L.

[0075] The ratio of the volume of the plating solution circulation chamber to the volume of the anode chamber (volume of the plating solution circulation chamber / volume of the anode chamber) is not particularly limited, but is preferably 0.005 to 0.5, more preferably 0.01 to 0.2, and most preferably 0.01 to 0.1. By keeping the above ratio within the above numerical range, passivation of the anode surface can be further suppressed.

[0076] The flow rate when circulating the plating solution to the plating solution circulation chamber is not particularly limited, and a flow rate can be selected that does not cause excessive changes in the concentration of the plating solution in the plating solution circulation chamber, depending on the required metal ion supply rate (electrolysis rate per unit time). On the other hand, when electrolysis is not performed, it is preferable to stop the circulation or reduce the flow rate sufficiently in order to minimize ion diffusion across the first diaphragm. However, if the circulation is stopped, there is a risk that crystals or the like may precipitate in the plating solution circulation chamber due to compositional changes caused by ion diffusion across the first diaphragm. Therefore, if the circulation is stopped for a certain period of time or longer, it is preferable to drain the plating solution from the plating solution circulation chamber or to periodically circulate the solution to replace the plating solution in the plating solution circulation chamber.

[0077] (Plating solution) The metal ion supply system of this embodiment may further include the plating solution contained in the plating solution circulation chamber. The composition of the above plating solution can be appropriately set according to the metal to be plated in the electroplating apparatus. The composition of the plating solution is determined by the metal to be plated in the electroplating apparatus, and the combination of anode and anolite is determined according to the composition of the plating solution. The plating solution may contain ions of the same metal as the metal contained in the anode. For example, if Cu is used as the metal of the anode, the plating solution may contain Cu 2+ It may contain ions. The metal included in the above anode can be the metal described above in the anode section.

[0078] The concentration of ions of the same metal as the metal contained in the anode in the plating solution is not particularly limited, and an appropriate concentration can be selected according to the type of metal to be plated, the specifications of the plating film, and the required uniformity of the plating film. For example, the concentration of ions of the same metal as the metal contained in the anode can be 20-80 g / L, 30-70 g / L, or 30-65 g / L. By keeping the concentration within the above numerical range, the effect of excellent uniformity and productivity of the plating film can be obtained.

[0079] The plating solution is not particularly limited, but copper sulfate plating solution, Sn alloy plating solution, or nickel sulfamate plating solution can be used. Of these, copper sulfate plating solution is particularly suitable.

[0080] (1st diaphragm) The first diaphragm is positioned between the anode chamber and the plating solution circulation chamber. The first diaphragm is not particularly limited, but an ion exchange membrane or a neutral porous membrane can be used. Among these, an ion exchange membrane is preferred. The ion exchange membrane is not particularly limited, but a cation exchange membrane is preferred. By using a cation exchange membrane, metal ions contained in the anolite in the anode chamber can be transferred to the plating solution circulation chamber. The cation exchange membrane can be a fluorine-based cation exchange membrane or a hydrocarbon-based cation exchange membrane. Among these, a fluorine-based cation exchange membrane is preferred in that it has excellent durability. In particular, when the anolite contains halide ions, the diaphragm tends to deteriorate easily, so a fluorine-based cation exchange membrane can be suitably used.

[0081] As for the fluorine-based cation exchange membranes mentioned above, commercially available products such as FORBLUE® Sx-2301 and Sx-1811 (both manufactured by AGC Inc.), Nafion® N424 and N438 (both manufactured by Chemours Company) can be used. As for hydrocarbon-based cation exchange membranes, commercially available products such as Celemion® CMVN (manufactured by AGC Inc.) and Neosepta® CSE (manufactured by Astrom Co., Ltd.) can be used.

[0082] The diffusion and osmosis rate of water in the first diaphragm is not particularly limited, but is 0.01 to 1 (mol / h·dm³). 2 (mol / L) is preferred, and 0.01 to 0.5 (mol / h·dm) is preferred. 2 (mol / L) is more preferable, and 0.01 to 0.2 (mol / h·dm) is preferred. 2 (mol / L) is the most preferred.

[0083] (Second diaphragm) The second diaphragm is positioned between the cathode chamber and the plating solution circulation chamber. The second diaphragm is not particularly limited, but a hydrogen ion selective permeable membrane, a bipolar membrane, or a monovalent cation selective permeable membrane can be used. Of these, a hydrogen ion selective permeable membrane or a bipolar membrane is particularly preferred. By using a hydrogen ion selective permeable membrane or a bipolar membrane, it is possible to suppress metal ions in the plating solution from permeating through the second diaphragm and entering the cathode chamber.

[0084] As the hydrogen ion selective permeable membrane mentioned above, commercially available products such as Celemion® HSFN (manufactured by AGC Engineering Co., Ltd.) can be used. As the bipolar membrane mentioned above, commercially available products such as Neosepta® BP-1EX (manufactured by Astrom Co., Ltd.) can be used.

[0085] The diffusion and osmosis rate of water in the second diaphragm is not particularly limited, but is 0.1 to 5 (mol / h·dm³). 2 (mol / L) is preferred, and 0.2 to 3 (mol / h·dm) 2 (mol / l) More preferably, 0.5~2 (mol / h·dm 2 (mol / L) is the most preferred.

[0086] In the metal ion supply system of this embodiment, it is preferable that the first diaphragm is a cation exchange membrane and the second diaphragm is a hydrogen ion selective permeable membrane or a bipolar membrane. By using such a combination, metal ions can be supplied to the plating solution with high current efficiency.

[0087] In the metal ion supply system of this embodiment, the diffusion and infiltration rate of water in the second diaphragm is greater than that of the first diaphragm. The difference between the water diffusion and osmosis rate of the second diaphragm and the water diffusion and osmosis rate of the first diaphragm is not particularly limited, but is greater than 0 and less than or equal to 5 (mol / h·dm 2 (mol / L) is preferred, and 0.1 to 3 (mol / h·dm) 2 (mol / L) is more preferable, and 0.2 to 2 (mol / h·dm) 2 (mol / l) is most preferred. The ratio of the diffusion rate of water in the second diaphragm to the diffusion rate of water in the first diaphragm (diffusion rate of water in the second diaphragm / diffusion rate of water in the first diaphragm) is not particularly limited, but is preferably greater than 1 and 100 or less, more preferably 3 to 50, and most preferably 5 to 30.

[0088] In the metal ion supply system of this embodiment, the catholite has a higher osmolality than the osmolality of the plating solution in the plating solution circulation chamber. By setting the osmolality of the cassolite and plating solution as described above, the movement of water from the plating solution to the cassolite by diffusion and permeation can be promoted. In this way, by promoting the movement of water by diffusion and permeation, excess water present in the plating solution can be released to the cassolite, thereby suppressing the dilution of the plating solution.

[0089] The osmolar concentration of the catholite is not particularly limited, but is preferably 1 to 15 mol / L, more preferably 2 to 10 mol / L, and most preferably 3 to 8 mol / L.

[0090] The osmolality of the plating solution in the plating solution circulation chamber is not particularly limited, but is preferably 0.5 to 10 mol / L, more preferably 1 to 8 mol / L, and most preferably 2 to 5 mol / L.

[0091] The difference between the osmolality of the catholite and the osmolality of the plating solution in the plating solution circulation chamber is not particularly limited, but is preferably 0.1 to 10 mol / L, more preferably 0.2 to 8 mol / L, and most preferably 0.5 to 5 mol / L. The ratio of the osmolality of catholite to the osmolality of the plating solution in the plating solution circulation chamber (osmolality of catholite / osmolality of the plating solution) is not particularly limited, but is preferably 1.1 to 10, more preferably 1.2 to 5, and most preferably 1.5 to 3.

[0092] (Other configurations) The metal ion supply system of this embodiment may further include an external power supply connected to the cathode and anode. Preferably, the external power supply is equipped with a reverse current prevention mechanism (such as a diode). By installing a reverse current prevention mechanism, it is possible to prevent reverse current from flowing and causing metal ions to move into the anolite when the system is stopped.

[0093] In this embodiment, the metal ion supply system may further include a reserve tank for circulating catholite between it and the cathode chamber. Furthermore, an oxygen-containing gas (such as air) can be blown into (bubbled) within the reserve tank. An example of the reserve tank is described below.

[0094] Figure 2 is an enlarged view of the area around the cathode chamber in the metal ion supply system. The metal ion supply system includes a cathode chamber 1300, a cathode 1700, a second diaphragm 1500, etc. In the metal ion supply system shown in Figure 2, a reserve tank 1310 is provided, which can circulate catholite between itself and the cathode chamber 1300.

[0095] Metal ions (Sn) that have moved from the plating solution circulation chamber via the second diaphragm 1500 are present in the catholite. 2+ (Sn, etc.) may be present in small amounts. These metal ions may precipitate on the cathode surface, and if such precipitation occurs, the electrolysis voltage will rise. When the above metal ions are oxidized by blowing an oxygen-containing gas into the reserve tank 1310, the oxidized metal ions (Sn 4+ (etc.) precipitate as hydroxides. The precipitated hydroxides can be removed by a filter. This removes metal ions (Sn) that have moved from the plating solution circulation chamber. 2+ This can suppress the deposition of substances such as on the cathode surface, thereby preventing the aforementioned increase in electrolysis voltage.

[0096] In the metal ion supply system of this embodiment, the plating solution circulation chamber located between the anode chamber and the cathode chamber can have a structure similar to that of an electrodialysis machine's cell structure. Specifically, as shown in Figure 3, the internal space of the gasket 1230 / spacer 1240 sandwiched between the first diaphragm 1400 supported by the frame 1110 and gasket 1120, and the second diaphragm 1500 supported by the frame 1320 and gasket 1330, can be used as the plating solution circulation chamber.

[0097] By adopting the structure described above, the volume of the plating solution circulation chamber can be minimized (to a width of approximately 1 mm). As a result, the effects of dilution and loss of the plating solution when replacing the contents of the plating solution circulation chamber with a liquid that substantially does not contain at least one of the above-mentioned metal ions can be minimized.

[0098] In the metal ion supply system of this embodiment, the plating solution circulation chamber may be a space defined by a first diaphragm and a second diaphragm, which are supported by a frame, respectively.

[0099] (Electrolytic plating equipment) The metal ion supply system of this embodiment is a system for supplying metal ions to an electroplating apparatus. A configuration of the electroplating apparatus will be described below.

[0100] (Configuration of the plating tank) Figure 4 is a schematic side view showing the configuration of a plating tank in an electrolytic plating apparatus. During the plating process, the plating tank 10 contains a substrate holder 11 that holds the substrate W, an anode unit 12 that holds the anode electrode AN, a regulation plate 14, and a paddle 15. The plating tank 10 contains the plating solution, and the substrate W and the anode electrode AN are immersed in the plating solution. The anode unit 12 has an anode holder 200 that holds the anode electrode AN and an anode mask 300 for adjusting the electric field between the anode electrode AN and the substrate W. In one example, the anode unit 12 is housed in an anode box 13. An opening is provided in the anode box 13 at a position facing the anode electrode AN, and a diaphragm 13a is placed in the opening. The anode mask 300 includes one or more substantially plate-shaped members made of, for example, a dielectric material. The regulation plate 14 has an opening and adjusts the electric field between itself and the substrate W, similar to the anode mask 300. In one example, the dimensions of the opening of the regulation plate 14 are fixed, and regulation plates with different opening dimensions are interchangeable. In another example, the dimensions of the opening of the regulation plate 14 are adjustable. The paddle 15 agitates the plating solution near the surface of the substrate W to be plated. The paddle 15 can be, for example, a roughly rod-shaped member and can be installed in the plating bath 10 so as to face vertically. The paddle 15 is configured to move horizontally along the surface of the substrate W to be plated by a drive device (not shown). Alternatively, the paddle 15 may be a plate-shaped member with multiple vertical slits. Note that, from the viewpoint of plating quality, (dew on the surface of the substrate W to be plated) It is preferable that the relationship (exposed area or dimensions) > (aperture area or dimensions of the regulation plate) > (aperture area or dimensions of the anode mask) holds true. In this case, the area or dimensions of the substrate W itself are larger than the area or dimensions of the opening of the regulation plate. Therefore, it is preferable that the aperture area (or aperture dimensions) of the anode mask and the aperture area (or aperture dimensions) of the regulation plate be set and / or adjusted so as to satisfy the above relationship.

[0101] The anode electrode AN is connected to an external power supply (not shown) via wiring in the anode holder 200. The surface of the substrate W to be plated is also connected to the external power supply via wiring in the substrate holder 11. When voltage is supplied from the external power supply between the anode electrode AN and the substrate W, a plating current flows from the external power supply through the anode electrode AN, the plating solution, the seed layer on the surface of the substrate W to be plated, and back to the external power supply. As a result, the metal in the plating solution is deposited on the surface of the substrate W to be plated, and the substrate W is plated.

[0102] The plating tank 10 is provided with a circulation mechanism 700 that circulates the plating solution between the plating tank 10 and the outer tank 16. The system comprises the circulation mechanism 700, the outer tank 16 which receives the plating solution overflowing from the plating tank 10, and a circulation line 702 connecting the plating tank 10 and the outer tank 16. In one example, the circulation line 702 is connected to the bottom of the plating tank 10 and the bottom of the outer tank 16. The circulation line 702 is provided with a valve 704 which can be opened and closed. The valve 704 can be, for example, a solenoid valve, and the opening and closing of the circulation line 702 can be controlled by a control unit (not shown). The circulation line 702 is provided with a pump 706 which can circulate the plating solution from the outer tank 16 to the plating tank 10 through the circulation line 702. The circulation line 702 is provided with a temperature control device 708 which can control the temperature of the plating solution passing through the circulation line 702. For example, a thermometer (not shown) may be provided in the plating tank 10, and the control unit 103 may control the temperature control device 708 according to the plating solution temperature measured by this thermometer. A filter 710 is provided in the circulation line 702 to remove solid matter from the plating solution passing through the circulation line 702.

[0103] The plating solution circulation chamber of the metal ion supply system of this embodiment is connected to the plating tank 10 shown in Figure 4, allowing metal ions to be supplied to the plating solution used in the plating apparatus. Alternatively, the plating solution circulation chamber of the metal ion supply system of this embodiment is connected to a reserve tank connected to the plating tank 10, allowing metal ions to be supplied to the plating solution used in the plating apparatus.

[0104] 2. Second Embodiment The method for supplying metal ions to an electroplating apparatus according to the second embodiment is: (i) A step of circulating a plating solution containing metal ions between a plating solution circulation chamber and an electrolytic plating apparatus to supply the metal ions to the electrolytic plating apparatus, and (ii) A step in which the metal ions are not supplied to the electroplating apparatus, wherein the plating solution circulation chamber is replaced with a liquid that substantially does not contain at least one of the metal ions. Includes. In step (ii), a step in which metal ions are not supplied, the metal ion supply method of this embodiment can suppress passivation of the anode surface caused by metal ions introduced from within the plating solution circulation chamber by replacing the contents of the plating solution circulation chamber with a liquid that substantially does not contain at least one of the metal ions.

[0105] The ionization tendency of the metal contained in the anode can be made greater than the ionization tendency of the metal that can be mixed in from the plating solution circulation chamber to the anode chamber. Therefore, the substitution in step (ii) of this embodiment becomes a more effective means, as the metal mixed in from the plating solution circulation chamber into the anode chamber is more likely to precipitate on the anode surface.

[0106] The following describes one embodiment of the metal ion supply method of this embodiment.

[0107] Figure 5 shows the overall process of the metal ion supply method. In Figure 5, a three-chamber cell (equipped with an anode chamber 1100, a first diaphragm 1400, a plating solution circulation chamber 1200, a second diaphragm 1500, and a cathode chamber 1300 in this order) is used, and the plating solution can be circulated between the plating solution circulation chamber 1200 and the electroplating apparatus.

[0108] Figure 5(A) is a diagram of the electrolysis process using a three-chamber cell (when metal ions are supplied). Figure 5(A) corresponds to step (i) above, the step of supplying metal ions. In Figure 5(A), valves V1 and V4 in the path between the electroplating apparatus and the plating solution circulation chamber 1200 of the three-chamber cell are open, while valves V2, V3, V5~V7 in the other paths are closed. In Figure 5(A), the plating solution flows from the electroplating apparatus to the plating solution circulation chamber 1200 of the three-chamber cell, and then from the plating solution circulation chamber 1200 back to the electroplating apparatus, circulating the plating solution (flow of the CSU pump and CSU return in Figure 5(A)).

[0109] Figure 5(B) is a diagram of the process of stopping electrolysis and draining the plating solution from the plating solution circulation chamber 1200. When moving from Figure 5(A) to (B), valves V1 and V4 in the path between the electrolytic plating apparatus and the plating solution circulation chamber 1200 are closed, while valve V2 between the gas supply unit 1250 and the plating solution circulation chamber 1200 and another valve V5 between the plating solution circulation chamber 1200 and the electrolytic plating apparatus are opened. In Figure 5(B), gas is supplied from the gas supply unit 1250 to the plating solution circulation chamber 1200, causing the plating solution in the plating solution circulation chamber 1200 to be pushed out of the electrolytic plating apparatus and move back into the electrolytic plating apparatus, filling the plating solution circulation chamber 1200 with gas. In Figure 5(B), nitrogen gas is used as the gas.

[0110] Figure 5(C) shows a step in which, with electrolysis stopped, the inside of the plating solution circulation chamber 1200 is replaced with a liquid that substantially does not contain at least one of the metal ions contained in the plating solution. Figure 5(C) corresponds to step (ii) above, the step in which no metal ions are supplied. When moving from Figure 5(B) to (C), valve V2 between the gas supply unit 1250 and the plating solution circulation chamber 1200 and another valve V5 between the plating solution circulation chamber 1200 and the electrolytic plating apparatus are closed, while valve V7 between the liquid supply unit 1260 that substantially does not contain at least one of the metal ions and the plating solution circulation chamber 1200 and valve V3 between the plating solution circulation chamber 1200 and the connection unit 1270 to the waste tank are opened. In Figure 5(C), the liquid that substantially does not contain at least one of the metal ions is supplied to the plating solution circulation chamber 1200, the inside of the plating solution circulation chamber 1200 is filled with the liquid, and the nitrogen gas that was originally filled is discarded. In Figure 5(C), DIW (ultrapure water) or MSA (methanesulfonic acid) is used as the liquid.

[0111] Figure 5(D) shows a step in which electrolysis is stopped and the plating solution circulation chamber 1200 is filled with a liquid that substantially does not contain at least one of the above-mentioned metal ions, and then left to stand. When moving from Figure 5(C) to (D), valves V1 to V7 in the path extending from the plating solution circulation chamber 1200 are closed. In Figure 5(D), since the plating solution circulation chamber 1200 is filled with a liquid that substantially does not contain at least one of the above-mentioned metal ions, the above-mentioned metal ions do not enter the anode chamber 1100. Therefore, metal derived from the above-mentioned metal ions does not precipitate on the anode surface, and passivation of the anode surface can be suppressed.

[0112] Figure 5(E) is a diagram of the process of discharging a liquid from the plating solution circulation chamber 1200 that substantially does not contain at least one of the above metal ions, with electrolysis stopped. When moving from Figure 5(D) to (E), valve V2 between the gas supply unit 1250 and the plating solution circulation chamber 1200 and valve V6 between the plating solution circulation chamber 1200 and the connection part 1280 to the waste tank are opened. In Figure 5(E), as gas is supplied to the plating solution circulation chamber 1200, the liquid that substantially does not contain at least one of the above metal ions inside the plating solution circulation chamber 1200 is pushed out and discarded, and the inside of the plating solution circulation chamber 1200 is filled with gas.

[0113] After step (E) in Figure 5, the electrolysis of the three-chamber cell can be restarted, and step (A) in Figure 5 described above can be repeated. Furthermore, after step (A) in Figure 5, steps (B) to (E) in Figure 5 can be repeated.

[0114] The components of the metal ion supply method of this embodiment will be described in more detail below.

[0115] (Plating solution circulation chamber) A plating solution circulation chamber can be positioned between the anode chamber and the cathode chamber. The plating solution circulation chamber may include an outlet for discharging the plating solution to the electroplating apparatus and an inlet for receiving the plating solution from the electroplating apparatus, allowing the plating solution to circulate. The plating solution circulation chamber can contain the plating solution.

[0116] The plating solution circulation chamber may be defined by a first diaphragm and a second diaphragm, as described later. For example, the plating solution circulation chamber may be a cell structure formed by a gasket or spacer sandwiched between a first diaphragm and a second diaphragm, which are supported by a frame.

[0117] The capacity of the plating solution circulation chamber is not particularly limited, and an appropriate capacity can be selected according to the required metal ion supply rate (electrolysis rate per hour), but 0.1 to 50 L is preferred, 0.2 to 20 L is more preferred, and 0.2 to 10 L is most preferred. By keeping the capacity within the above numerical range, the amount of liquid to be discharged and replaced in the plating solution circulation chamber can be reduced, and the time required for replacement can be shortened. In particular, by using the above cell structure for the plating solution circulation chamber, the width of the plating solution circulation chamber can be reduced to about 1 mm, and the capacity of the plating solution circulation chamber can be reduced.

[0118] In this embodiment, the volume of the plating solution circulation chamber can be reduced, thereby reducing the amount of plating solution remaining in the chamber. This reduces the amount of metal ions that enter the anode chamber from the plating solution circulation chamber, and as a result, the passivation of the anode surface described above can be further suppressed. For example, the volume of the plating solution circulation chamber can be reduced by reducing the distance between the first diaphragm and the second diaphragm. In such a case, the volume of the plating solution circulation chamber can be set to 0.2 to 5 L.

[0119] The ratio of the volume of the plating solution circulation chamber to the volume of the anode chamber (volume of the plating solution circulation chamber / volume of the anode chamber) is not particularly limited, but is preferably 0.005 to 0.5, more preferably 0.01 to 0.3, and most preferably 0.02 to 0.2. By keeping the above ratio within the above numerical range, passivation of the anode surface can be further suppressed.

[0120] The flow rate when circulating the plating solution to the plating solution circulation chamber is not particularly limited, and a flow rate can be selected that does not cause excessive changes in the concentration of the plating solution in the plating solution circulation chamber, depending on the required metal ion supply rate (electrolysis rate per unit time).

[0121] (A liquid that substantially does not contain at least one type of metal ion) The liquid used in step (ii) above, which is substantially free of at least one of the metal ions supplied to the electroplating apparatus, is not particularly limited, but it is preferable to use DIW (ultrapure water) or a solution of the acid contained in the plating solution. When using a plating solution containing MSA (MeSO3H, methanesulfonic acid) or a salt of methanesulfonic acid, an MSA solution can be used as the above liquid, and when using a plating solution containing sulfuric acid or a salt of sulfuric acid, a sulfuric acid solution can be used as the above liquid. By using DIW (ultrapure water) or a solution of the acid contained in the plating solution as the above liquid, the effect when it is mixed into the plating solution can be reduced.

[0122] If only one type of metal ion is supplied to the electroplating apparatus, the liquid shall substantially not contain that one type of metal ion. If two or more types of metal ions are supplied to the electroplating apparatus, the liquid shall not substantially contain one of the two or more types of metal ions, or it shall not substantially contain any of the two or more types of metal ions.

[0123] As the metal ions supplied to the electroplating apparatus, the metal ions described later, which are contained in the plating solution, can be used.

[0124] In this specification, "substantially free of at least one of the metal ions" means either that it does not contain at least one of the above metal ions, or that the concentration of at least one of the above metal ions is such that even if the at least one metal ion enters the anode chamber and displaces and precipitates on the anode surface, a voltage increase due to passivation does not occur. A "liquid substantially free of at least one of the metal ions" may be a liquid in which the concentration of the at least one metal ion in the liquid is 0.1 g / L or less. Alternatively, the liquid used in step (ii) above does not have to contain the above metal ions.

[0125] (Additional steps) The metal ion supply method of this embodiment may further include a step of discharging the plating solution or liquid in the plating solution circulation chamber to an external location other than the electroplating apparatus when switching between step (i) supplying metal ions and step (ii) not supplying metal ions. Such a step corresponds to step (B) or step (E) in Figure 5 described above.

[0126] The above discharge process may also be carried out by supplying gas into the plating solution circulation chamber to push out the plating solution or liquid. By using such a gas, the plating solution or liquid can be discharged efficiently.

[0127] The above gases are not particularly limited, but include nitrogen gas, argon gas, air, or a combination of two or more of these. Of these, nitrogen gas is preferred. By using nitrogen gas, Sn 2+ It can suppress the oxidation of metal ions that are easily oxidized by oxygen.

[0128] In the metal ion supply method of this embodiment, a metal ion supply system comprising an anode chamber, a cathode chamber, and the plating solution circulation chamber located between the anode chamber and the cathode chamber can be used. The metal ion supply system described above may be the same as the metal ion supply system described in "1. First Embodiment" above or the metal ion supply system described in "3. Third Embodiment" below.

[0129] (Anode chamber) The anode chamber can accommodate anodes and anolites. The capacity (size) of the anode chamber is not particularly limited, and the optimal size can be selected as appropriate depending on the required metal ion supply rate (electrolysis rate per hour) and the size of the anode to be housed. It is preferable that the anode chamber be equipped with a liquid level sensor and connected to a pure water supply line.

[0130] Water can be supplied to the anode chamber via a pure water supply line. By supplying the anode chamber with pure water equivalent to the amount of water that flows out into the plating solution circulation chamber as electroosmotic water through the first diaphragm during electrolysis, and the amount of water lost due to the evaporation of anolite, changes in the anolite concentration can be suppressed.

[0131] (anode) The anode is placed in the anode chamber. It is preferable to use a soluble anode. Alternatively, a combination of soluble and insoluble anodes can be used. By using a combination of soluble and insoluble anodes, the increase in the pH of the anolite due to electrolysis can be suppressed compared to when an insoluble anode is not used. Therefore, a decrease in the solubility of the anode can be prevented.

[0132] The metal included in the anode can be appropriately set depending on the type of metal to be plated. The metal included in the anode is not particularly limited, but Sn, Cu, Pb, SnPb, Ni, Ag, or Bi can be preferably used. Of these, Sn can be particularly preferably used.

[0133] The shape of the anode is not particularly limited, but it can be a sphere (ball), a disc, a slab, a rod, or a cylinder.

[0134] An anode may consist of one or more components. For example, a single plate-shaped anode (e.g., a rectangular or circular plate) may be used, or multiple small pieces of anode (e.g., spherical, granular, or rod-shaped) may be housed in a conductive case. For example, the anode may be multiple Sn balls or cylinders. When multiple small pieces of anode are used, the impact on the electrolytic reaction when the shape and size of the anode change due to consumption is small. Also, when multiple small pieces of anode are housed in a conductive case, it is sufficient to replenish the case with new anodes equivalent to the amount consumed, and there is no need to stop the device to replace the anode. The material of the case for filling the anode should be a metal that does not oxidize or dissolve due to the electrode reaction, and titanium lath mesh or perforated plates can be suitably used. The anode may also be housed in an anode bag. Using an anode bag can suppress or prevent sludge generated from the anode from mixing into the anolite. Anode bags can be made of woven or nonwoven fabrics, which are commonly used for anodes. Suitable materials for anode bags include chemical-resistant resin fibers such as polypropylene and polyvinylidene chloride.

[0135] (Anolite) Anolite fills the anode chamber. The anolite may contain ions of the same metal as the metal contained in the anode. For example, if Sn is used as the metal of the anode, the anolite will contain Sn 2+ It may contain ions. The metal included in the above anode can be the metal described above in the anode section.

[0136] The anolite can be an alkyl sulfonic acid solution such as MSA solution, a sulfuric acid solution, or a sulfamic acid solution, although this is not particularly limited. Of these, MSA solution is particularly suitable. If the anolite contains MSA solution, it may further contain H2SO4.

[0137] The metal ions contained in anolite are not particularly limited, but Sn2+ Cu 2+ , or Ni 2+ You can use Sn 2+ This can be used in particular.

[0138] The pH of the anolite is not particularly limited, but it is preferable to select a pH range that provides good stability of the metal ions, good solubility of the anode, and a high transport rate of metal ions when they permeate the first membrane, depending on the type of plating solution and the type of metal ions supplied. For example, when using a tin plating solution, the pH of the anolite is preferably 0 to 2, more preferably 0 to 1.5, and most preferably 0 to 1. By keeping the pH of the anolite within the above numerical range, metal ions can be supplied stably with high current efficiency.

[0139] Each step in the method of this embodiment can be performed with the anolite filled in the anode chamber.

[0140] In this embodiment, gas can be blown into the anolite (bubbling) to stir it. This allows for a uniform concentration distribution of the anolite, stabilizes the electrolytic voltage, and suppresses the precipitation of inorganic components.

[0141] The above gas is not particularly limited, but a non-reactive gas, air, or oxygen can be used. Nitrogen, carbon dioxide, or argon can be used as non-reactive gases. When the anolite contains easily oxidizable metal ions such as divalent Sn ions, it is preferable to use a non-reactive gas. Using a non-reactive gas reduces the dissolved oxygen in the anolite, suppressing the oxidation of the metal in the anolite and inhibiting the formation of the precipitate Sn(OH)4. Furthermore, using a non-reactive gas reduces the amount of Sn in the anolite. 2+ This method suppresses the decrease in concentration and reduces the consumption of anodes. The above gases can be used individually or in combination of two or more. In addition, other stirring methods such as paddle stirring or jet stirring can be used instead of or in addition to the above bubbling, and multiple stirring methods can also be used in combination.

[0142] (Cathode chamber) The cathode chamber can accommodate the cathode and the cathodeite. The capacity (size) of the cathode chamber is not particularly limited, and the optimal size can be selected as appropriate depending on the required metal ion supply rate (electrolysis rate per hour) and the size of the cathode to be housed.

[0143] The cathode chamber preferably includes level sensors for detecting three levels: the upper limit level of the cassolite liquid level (cassolite upper limit level), the lower limit level of the cassolite liquid level (cassolite lower limit level), and the cassolite supply level, as well as a cassolite supply line and a discharge line linked to these sensors. Since the electroosmotic water produced during electrolysis and the osmolar concentration difference between the electroosmotic water and the plating solution are supplied to the cassolite via the second diaphragm, the cassolite is diluted and the liquid level gradually rises. When the liquid level reaches the cassolite upper limit level, the cassolite is discharged from the discharge port down to the cassolite lower limit level. After discharge, the cassolite concentration can be controlled within a certain range by supplying cassolite from the cassolite supply line until it reaches the cassolite supply level. Alternatively, instead of using level sensors, flow meters may be installed in the cassolite supply line and discharge line to supply and discharge a fixed amount of cassolite. Furthermore, if a separate reserve tank is installed to circulate the cathode rayite between the cathode chamber and the reservoir, the level sensor and supply / discharge lines mentioned above can also be installed in the reserve tank.

[0144] (Cathode) The cathode is installed in the cathode chamber. The cathode is not particularly limited, but an inert cathode or an insoluble cathode can be used, and an inert and insoluble cathode can be used in particular. By using an inert and insoluble cathode, there is no elution of components into the catholite, and the composition of the catholite can be stabilized.

[0145] The metal contained in the cathode is not particularly limited, but Pt, Ti, Nb, a metal coated with Pt, or a combination of two or more of these can be used. Among these, Pt-coated Ti is preferred. When Pt-coated Ti is used, the insoluble Pt coats the Ti surface, resulting in an inert and insoluble cathode, and since metal ions do not leach from the cathode, there is no change in the composition of the cathode.

[0146] The shape of the cathode is not particularly limited, but it can be a rod, a ball, a disc, or a slab. If the cathode is a disc or a slab, it may have multiple through-holes, such as in a perforated metal plate or expanded metal plate. By having multiple through-holes, the surface area of ​​the cathode can be increased, and the electrolytic voltage can be kept low even at high current densities. The cathode may consist of one or more components.

[0147] (Catholite) The catholite is filled into the cathode chamber. The cassolite is not particularly limited, but it is preferably a solution of an anionic acid that is included as the main component in the plating solution used in combination. When used in combination with a tin methanesulfonate alloy plating solution, an MSA solution is preferred for the cassolite. By using a solution of an anionic acid that is included as the main component in the plating solution, even if a small amount of cassolite enters the plating solution from the diaphragm or seal, the impact on the plating solution can be minimized.

[0148] The catholite may substantially contain no ions of the same metal as the metal contained in the anode. The "metal contained in the anode" above may be the metal described above in the section on anodes. In this specification, "substantially contains no ions of the same metal as the metal contained in the anode" means that the concentration of ions of that metal is 0.1 g / L or less.

[0149] In this embodiment, gas can be blown into the catholite (bubbling) to perform stirring. This allows for a uniform concentration distribution of the catholite and a stabilization of the electrolytic voltage. The gas is not particularly limited and the same gas used to stir the anolite described above can be used. The gas can be used alone or in combination of two or more types. In addition to or instead of the above bubbling, other stirring methods such as paddle stirring or jet stirring can be used, and multiple stirring methods can also be used in combination.

[0150] Each step in the method of this embodiment can be performed with the cathode chamber filled with catholite.

[0151] In this embodiment, any one of the following combinations of anode, anolite, cathode, and catholite (1) to (3) can be adopted. (1) Anode: Sn pellet, Anolite: Mixed solution of tin methanesulfonate and MSA, Cathode: Pt-coated Ti mesh, Catholite: MSA solution (2) Anode: Cu ball, Anolite: Mixed solution of copper sulfate and sulfuric acid, Cathode: Pt-coated Ti mesh, Catholite: Sulfuric acid solution (3) Anode: Ni ball, Anolite: Mixed solution of nickel sulfamate and boric acid, Cathode: Pt coated Ti mesh, Castholite: Sulfamic acid solution

[0152] (Plating solution) The metal ion supply system of this embodiment may further include the plating solution contained in the plating solution circulation chamber. The composition of the above plating solution can be appropriately set according to the metal to be plated in the electroplating apparatus. The composition of the plating solution is determined by the metal to be plated in the electroplating apparatus, and the combination of anode and anolite is determined according to the composition of the plating solution. The above plating solution may contain ions of the same metal as the metal contained in the anode. For example, if Sn is used as the metal of the anode, the plating solution will contain Sn 2+It may contain ions. The metal included in the above anode can be the metal described above in the anode section.

[0153] The concentration of ions of the same metal as the metal contained in the anode in the plating solution is not particularly limited, and an appropriate concentration can be selected according to the type of metal to be plated, the specifications of the plating film, and the required uniformity of the plating film. For example, the concentration of ions of the same metal as the metal contained in the anode can be 10-200 g / L, 20-150 g / L, or 30-100 g / L. Excellent uniformity of the plating film is achieved when the concentration is within the above numerical range.

[0154] The plating solution is not particularly limited, but a tin alloy plating solution, a copper sulfate plating solution, or a nickel sulfamate plating solution can be used. Of these, the tin alloy plating solution is particularly suitable.

[0155] The plating solution circulating between the plating solution circulation chamber and the electroplating apparatus contains metal ions. These metal ions are not particularly limited, but may include Ag + Sn 2+ Cu 2+ , Bi 3+ Alternatively, combinations of two or more of these are possible. Among these, Ag + and Sn 2+ This combination can be particularly useful.

[0156] The ionization tendency of the metal contained in the anode can be made greater than the ionization tendency of the metal that may be introduced from the plating solution circulation chamber into the anode chamber. One of the following combinations (1) to (3) can be adopted as a combination of metals having such a relationship of ionization tendencies. (1) Metals contained in the anode: Sn, Metals that may be mixed into the anode chamber from the plating solution circulation chamber: Ag (2) Metals contained in the anode: Sn, Metals that may be mixed into the anode chamber from the plating solution circulation chamber: Cu (3) Metals contained in the anode: Sn, Metals that may be mixed into the anode chamber from the plating solution circulation chamber: Bi

[0157] (1st diaphragm) The first diaphragm is positioned between the anode chamber and the plating solution circulation chamber. The first diaphragm is not particularly limited, but an ion exchange membrane or a neutral porous membrane can be used. Among these, an ion exchange membrane is preferred. The ion exchange membrane is not particularly limited, but a cation exchange membrane is preferred. By using a cation exchange membrane, metal ions contained in the anolite in the anode chamber can be transferred to the plating solution circulation chamber. The cation exchange membrane can be a fluorine-based cation exchange membrane or a hydrocarbon-based cation exchange membrane. Among these, a fluorine-based cation exchange membrane is preferred in that it has excellent durability. In particular, when the anolite contains halide ions, the diaphragm tends to deteriorate easily, so a fluorine-based cation exchange membrane can be suitably used.

[0158] The above-mentioned fluorine-based cation exchange membranes include FORBLUE® Sx-2301 and Sx-1811 (both manufactured by AGC Inc.), and Nafion® N424 and N438 (both manufactured by Chemours). The hydrocarbon-based cation exchange membranes include Celemion® CMVN (manufactured by AGC Inc.) and Neosepta® CSE (manufactured by AGC Inc.). Commercially available products (such as those manufactured by Astom Co., Ltd.) can be used.

[0159] The diffusion and osmosis rate of water in the first diaphragm is not particularly limited, but is 0.01 to 1 (mol / h·dm³). 2 (mol / L) is preferred, and 0.01 to 0.5 (mol / h·dm) is preferred. 2 (mol / L) is more preferable, and 0.01 to 0.2 (mol / h·dm) is preferred. 2 (mol / L) is the most preferred.

[0160] (Second diaphragm) The second diaphragm is positioned between the cathode chamber and the plating solution circulation chamber. The second diaphragm is not particularly limited, but a hydrogen ion selective permeable membrane, a bipolar membrane, or a monovalent cation selective permeable membrane can be used. Of these, a hydrogen ion selective permeable membrane or a bipolar membrane is particularly preferred. By using a hydrogen ion selective permeable membrane or a bipolar membrane, it is possible to suppress metal ions in the plating solution from permeating through the second diaphragm and entering the cathode chamber.

[0161] As the hydrogen ion selective permeable membrane mentioned above, commercially available products such as Celemion® HSFN (manufactured by AGC Engineering Co., Ltd.) can be used. As the bipolar membrane mentioned above, commercially available products such as Neosepta® BP-1EX (manufactured by Astrom Co., Ltd.) can be used.

[0162] The diffusion and osmosis rate of water in the second diaphragm is not particularly limited, but is 0.1 to 5 (mol / h·dm³). 2 (mol / L) is preferred, and 0.2 to 3 (mol / h·dm) 2 (mol / L) is more preferable, and 0.5 to 2 (mol / h·dm) 2 (mol / L) is the most preferred.

[0163] In a metal ion supply system, it is preferable that the first diaphragm is a cation exchange membrane and the second diaphragm is a hydrogen ion selective permeable membrane or a bipolar membrane. This combination allows for the supply of metal ions to the plating solution with high current efficiency.

[0164] In a metal ion supply system, the diffusion and infiltration rate of water in the second diaphragm may be greater than that of water in the first diaphragm. The difference between the water diffusion and osmosis rate of the second diaphragm and the water diffusion and osmosis rate of the first diaphragm is not particularly limited, but is greater than 0 and less than or equal to 5 (mol / h·dm 2 (mol / L) is preferred, and 0.1 to 3 (mol / h·dm) 2 (mol / L) is more preferable, and 0.2 to 2 (mol / h·dm) 2(mol / l) is most preferred. The ratio of the diffusion rate of water in the second diaphragm to the diffusion rate of water in the first diaphragm (diffusion rate of water in the second diaphragm / diffusion rate of water in the first diaphragm) is not particularly limited, but is preferably greater than 1 and 100 or less, more preferably 3 to 50, and most preferably 5 to 30.

[0165] (Other configurations) The metal ion supply system may further include an external power supply connected to the cathode and anode. Preferably, the external power supply is equipped with a reverse current prevention mechanism (such as a diode). By installing a reverse current prevention mechanism, it is possible to prevent reverse current from flowing and causing metal ions to move into the anolite when the system is stopped.

[0166] In this embodiment, the metal ion supply system may further include a reserve tank for circulating catholite between it and the cathode chamber. Furthermore, an oxygen-containing gas (such as air) can be blown into (bubbled) within the reserve tank. An example of the reserve tank is described below.

[0167] Figure 2 is an enlarged view of the area around the cathode chamber in the metal ion supply system. The metal ion supply system includes a cathode chamber 1300, a cathode 1700, a second diaphragm 1500, etc. In the metal ion supply system shown in Figure 2, a reserve tank 1310 is provided, which can circulate catholite between itself and the cathode chamber 1300.

[0168] Metal ions (Sn) that have moved from the plating solution circulation chamber via the second diaphragm 1500 are present in the catholite. 2+ (Sn, etc.) may be present in small amounts. These metal ions may precipitate on the cathode surface, and if such precipitation occurs, the electrolysis voltage will rise. When the above metal ions are oxidized by blowing an oxygen-containing gas into the reserve tank 1310, the oxidized metal ions (Sn 4+(etc.) precipitate as hydroxides. The precipitated hydroxides can be removed by a filter. This removes metal ions (Sn) that have moved from the plating solution circulation chamber. 2+ This can suppress the deposition of substances such as on the cathode surface, thereby preventing the aforementioned increase in electrolysis voltage.

[0169] In the metal ion supply system of this embodiment, the plating solution circulation chamber located between the anode chamber and the cathode chamber can have a structure similar to that of an electrodialysis machine's cell structure. Specifically, as shown in Figure 3, the internal space of the gasket 1230 / spacer 1240 sandwiched between the first diaphragm 1400 supported by the frame 1110 and gasket 1120, and the second diaphragm 1500 supported by the frame 1320 and gasket 1330, can be used as the plating solution circulation chamber.

[0170] By adopting the structure described above, the volume of the plating solution circulation chamber can be minimized (to a width of approximately 1 mm). As a result, the effects of dilution and loss of the plating solution when replacing the contents of the plating solution circulation chamber with a liquid that substantially does not contain at least one of the above-mentioned metal ions can be minimized. The plating solution circulation chamber in the metal ion supply system may be a space defined by a first diaphragm and a second diaphragm, each supported by a frame.

[0171] The metal ion supply system is a system for supplying metal ions to the electroplating apparatus. The electroplating apparatus can be the same as the electroplating apparatus described in "1. First Embodiment" above.

[0172] 3. Third Embodiment The metal ion supply system for the electroplating apparatus of the third embodiment is: An anode chamber containing an anode and filled with anolite, A cathode chamber containing a cathode and filled with catholite, A first plating solution circulation chamber defined by a first diaphragm and a second diaphragm and disposed between the anode chamber and the cathode chamber, and One or more stacked modules disposed between the first plating solution circulation chamber and the cathode, the one or more stacked modules including an anolyte chamber filled with anolyte and a second plating solution circulation chamber defined by a third diaphragm and a fourth diaphragm. Comprising The third diaphragm is made of the same material as the first diaphragm, and the fourth diaphragm is made of the same material as the second diaphragm. The first plating solution circulation chamber and the second plating solution circulation chamber each include an outlet for discharging the plating solution to an electrolytic plating apparatus and an inlet for receiving the plating solution from the electrolytic plating apparatus so that the plating solution can circulate. The anolyte chamber includes an outlet for discharging anolyte from the anolyte chamber and an inlet for receiving anolyte into the anolyte chamber so as to enable fluid communication of the anolyte in the anode chamber. By including the one or more stacked modules, the metal ion supply system of the present embodiment can suppress the generation of sludge in the anolyte in the anode chamber and on the diaphragm.

[0173] Hereinafter, one form of the metal ion supply system of the present embodiment will be described.

[0174] FIG. 6 is a cross-sectional view showing the overall configuration of the metal ion supply system.

[0175] In FIG. 6, the metal ion supply system 3000 includes an anode chamber 1100, a first plating solution circulation chamber 2200, a stacked module 2800, and a cathode chamber 1300. The first plating solution circulation chamber 2200 is defined by a first diaphragm 2400 and a second diaphragm 2450. An anode 1600 is installed in the anode chamber 1100, and anolyte is filled therein. A cathode 1700 is installed in the cathode chamber 1300, and catholyte is filled therein.

[0176] The stacked module 2800 includes an anolite chamber 2810 and a second plating solution circulation chamber 2820. The second plating solution circulation chamber 2820 is defined by a third diaphragm 2500 and a fourth diaphragm 2550. The anolite chamber 2810 is filled with anolite. The anolite chamber 2810 has an outlet 2811 for discharging anolite from the anolite chamber 2810 and an inlet 2812 for receiving anolite into the anolite chamber 2810, so as to enable fluid communication with the anolite in the anode chamber 1100. The anode chamber 1100 and the anolite chamber 2810 are connected by pipes 2813 and 2814. Anolite can move from the anolite chamber 2810 to the anode chamber 1100 through pipe 2813, and from the anode chamber 1100 to the anolite chamber 2810 through pipe 2814.

[0177] The first plating solution circulation chamber 2200 and the second plating solution circulation chamber 2820 are equipped with outlets 2210 and 2821 for discharging the plating solution to the electroplating apparatus and inlets 2220 and 2822 for receiving the plating solution from the electroplating apparatus, so that the plating solution can be circulated.

[0178] External power supplies 1900 (shown in Figure 7, described later) are connected to the anode 1600 and cathode 1700. As indicated by the arrows, the plating solution is discharged from the first plating solution circulation chamber 2200 and the second plating solution circulation chamber 2820 to the electroplating apparatus, and the plating solution flows from the electroplating apparatus to the first plating solution circulation chamber 2200 and the second plating solution circulation chamber 2820. In addition, nitrogen 2950 is supplied into the anolite through the diffuser pipe 1800.

[0179] In the metal ion supply system 3000 shown in Figure 6, the first diaphragm 2400 and the third diaphragm 2500 are fluorine-based cation exchange membranes, the second diaphragm 2450 and the fourth diaphragm 2550 are hydrogen ion selective permeable membranes or bipolar membranes, the anode 1600 is a Sn ball, and the cathode 1700 is a Pt-coated Ti network.

[0180] Figure 7 is a cross-sectional view showing the movement of ions in the metal ion supply system. In Figure 7, when Sn passes through the first diaphragm 2400 or the third diaphragm 2500 which is a cation exchange membrane 2+ let the transport rate of Sn be t Sn In this specification, the transport rate means the ratio of the current carried by a certain ion to the total current when an electric current is passed through a solution of an electrolyte.

[0181] When 1 mol of Sn 2+ dissolves from the anode 1600 into the anolyte by electrolysis (2 faradays), the amount of substance of Sn 2+ passing through the first diaphragm 2400 or the third diaphragm 2500 is t Sn mol. Therefore, a total of 2t Sn mol of Sn 2+ moves from the anolyte to the plating solution. On the other hand, since the second diaphragm 2450 and the fourth diaphragm 2550 which are hydrogen ion selective permeable membranes or bipolar membranes do not allow Sn 2+ to pass through, the change in the amount of substance of Sn 2+ in the anolyte in total is (1 - 2t Sn ) mol.

[0182] Here, when t Sn > 0.5, (1 - 2t Sn ) < 0. Therefore, with electrolysis, the amount of Sn 2+ in the anolyte decreases (H + increases). When the concentration of Sn 2+ in the anolyte decreases, t Sn also becomes smaller. Finally, t Sn = 0.5 and a steady state is reached.

[0183] On the other hand, when t Sn <0.5, (1 - 2t Sn ) > 0. Therefore, with electrolysis, the amount of Sn 2+ in the anolyte increases (H + decreases). When the concentration of Sn 2+ in the anolyte increases, t SnBecause it also becomes larger, ultimately t Sn The value becomes 0.5, and a steady state is reached.

[0184] t Sn If =0.5, (1-2t Sn Since )=0, along with electrolysis, Sn in the anorite 2+ The quantity does not change (H + (It also remains unchanged). Also, at this time, 1 mol of Sn 2+ It is supplied from the anolite to the plating solution.

[0185] As described above, anolite is produced through electrolysis, along with t Sn The anolite composition naturally adjusts to a ratio of 0.5. Therefore, anolite concentration management only requires replenishing water lost through electroosmosis, etc., and no other special anolite concentration management is necessary.

[0186] Also, t Sn In an anolite composition of =0.5, there is a sufficient concentration of H to dissolve the sludge Sn(OH)2. + Because of its presence, the generation of sludge can be suppressed.

[0187] In Figure 7, the metal ions in the anolite are Sn 2+ Although the example given uses a single stacked module, the type of metal ions in the anorite and / or the number of stacked modules can be changed. For example, if the stability of the metal ions in the anorite is low when the pH rises (low solubility of hydroxide ions), the number of stacked modules can be increased to lower the pH of the anorite in the steady state to a pH lower than the pH at which hydroxide ions precipitate, thereby suppressing sludge formation, similar to the example in Figure 7.

[0188] The following describes in more detail each component of the metal ion supply system of this embodiment.

[0189] (Anode chamber) The anode chamber can accommodate anodes and anolites. The capacity (size) of the anode chamber is not particularly limited, and an appropriate optimal size can be selected according to the required metal ion supply rate (amount of electrolysis per unit time) and the size of the anode to be accommodated. The anode chamber preferably includes a liquid level sensor and is connected to a pure water supply line.

[0190] Water can be replenished into the anode chamber through the pure water supply line. By replenishing the anode chamber with an amount of pure water corresponding to the amount of water that permeates through the first diaphragm as electroosmotic water and flows out into the plating solution circulation chamber during electrolysis, and the amount of water reduced due to the evaporation of the anolyte, the change in the concentration of the anolyte can be suppressed.

[0191] (Anode) The anode is installed in the anode chamber. It is preferable to use a soluble anode. Also, a combination of a soluble anode and an insoluble anode can be used. By using a combination of a soluble anode and an insoluble anode, the increase in the pH of the anolyte due to electrolysis can be suppressed as compared with the case where an insoluble anode is not used in combination. Therefore, it is possible to prevent the solubility of the anode from decreasing.

[0192] The metal contained in the anode can be appropriately set according to the type of metal to be plated. The metal contained in the anode is not particularly limited, but Sn, Cu, Pb, SnPb, Ni, Ag, or Bi can be preferably used. Among these, Sn can be particularly preferably used.

[0193] The shape of the anode is not particularly limited, and it can be in the shape of a sphere (ball), disk, slab, rod, or cylinder.

[0194] An anode may consist of one or more components. For example, a single plate-shaped anode (e.g., a rectangular or circular plate) may be used, or multiple small pieces of anode (e.g., spherical, granular, or rod-shaped) may be housed in a conductive case. For example, the anode may be multiple Sn balls or cylinders. When multiple small pieces of anode are used, the impact on the electrolytic reaction when the shape and size of the anode change due to consumption is small. Also, when multiple small pieces of anode are housed in a conductive case, it is sufficient to replenish the case with new anodes equivalent to the amount consumed, and there is no need to stop the device to replace the anode. The material of the case for filling the anode should be a metal that does not oxidize or dissolve due to the electrode reaction, and titanium lath mesh or perforated plates can be suitably used. The anode may also be housed in an anode bag. Using an anode bag can suppress or prevent sludge generated from the anode from mixing into the anolite. Anode bags can be made of woven or nonwoven fabrics, which are commonly used for anodes. Suitable materials for anode bags include chemical-resistant resin fibers such as polypropylene and polyvinylidene chloride.

[0195] (Anolite) Anolite fills the anode chamber. The anolite may contain ions of the same metal as the metal contained in the anode. For example, if Sn is used as the metal of the anode, the anolite will contain Sn 2+ It may contain ions. The metal included in the above anode can be the metal described above in the anode section.

[0196] The anolite can be an alkyl sulfonic acid solution such as MSA solution, a sulfuric acid solution, or a sulfamic acid solution, although this is not particularly limited. Of these, MSA solution is particularly suitable. If the anolite contains MSA solution, it may further contain H2SO4.

[0197] The metal ions contained in anolite are not particularly limited, but Sn2+ Cu 2+ , or Ni 2+ You can use this. You can use this. Among these, Sn 2+ This can be used in particular.

[0198] The pH of the anolite is not particularly limited, but it is preferable to select a pH range that provides good stability of the metal ions, good solubility of the anode, and a high transport rate of metal ions when they permeate the first membrane, depending on the type of plating solution and the type of metal ions supplied. For example, when using a tin plating solution, the pH of the anolite is preferably 0 to 2, more preferably 0 to 1.5, and most preferably 0 to 1. By keeping the pH of the anolite within the above numerical range, metal ions can be supplied stably with high current efficiency.

[0199] In this embodiment, gas can be blown into the anolite (bubbling) to stir it. This allows for a uniform concentration distribution of the anolite, stabilizes the electrolytic voltage, and suppresses the precipitation of inorganic components.

[0200] The above gas is not particularly limited, but can be a non-reactive gas, air, or oxygen. As a non-reactive gas, nitrogen, carbon dioxide, or argon can be used. The anolite is divalent. When the anolite contains easily oxidizable metal ions such as Sn ions, it is preferable to use a non-reactive gas. Using a non-reactive gas reduces the amount of dissolved oxygen in the anolite, suppressing the oxidation of the metal in the anolite and inhibiting the formation of the precipitate Sn(OH)4. In addition, using a non-reactive gas reduces the amount of Sn in the anolite. 2+ This method suppresses the decrease in concentration and reduces the consumption of anodes. The above gases can be used individually or in combination of two or more. In addition to or instead of the above bubbling, other stirring methods such as paddle stirring or jet stirring can be used, and multiple stirring methods can be used in combination. The above stirring methods can be installed in the anode chamber and / or anolite chamber.

[0201] (Cathode chamber) The cathode chamber can accommodate the cathode and the cathodeite. The capacity (size) of the cathode chamber is not particularly limited, and the optimal size can be selected as appropriate depending on the required metal ion supply rate (electrolysis rate per hour) and the size of the cathode to be housed.

[0202] The cathode chamber preferably includes level sensors for detecting three levels: the upper limit level of the cassolite liquid level (cassolite upper level), the lower limit level of the cassolite liquid level (cassolite lower level), and the cassolite supply level, as well as a cassolite supply line and discharge line linked to these sensors. As electrolysis-induced electroosmotic water and osmolar water due to the osmolar concentration difference with the plating solution are supplied to the cassolite via the second diaphragm, the cassolite is diluted and the liquid level gradually rises. When the liquid level reaches the cassolite upper level, the cassolite is discharged from the discharge port down to the cassolite lower level. After discharge, the cassolite concentration can be controlled within a certain range by supplying cassolite from the cassolite supply line until it reaches the cassolite supply level. Alternatively, instead of using level sensors, flow meters may be installed in the cassolite supply line and discharge line to supply and discharge a fixed amount of cassolite. Furthermore, if a separate reserve tank is installed to circulate the cathode rayite between the cathode chamber and the reservoir, the level sensor and supply / discharge lines mentioned above can also be installed in the reserve tank.

[0203] (Cathode) The cathode is installed in the cathode chamber. The cathode is not particularly limited, but an inert cathode or an insoluble cathode can be used, and an inert and insoluble cathode is particularly useful. By using an inert and insoluble cathode, there is no elution of components into the catholite, and the composition of the catholite can be stabilized.

[0204] The metal contained in the cathode is not particularly limited, but Pt, Ti, Nb, a metal coated with Pt, or a combination of two or more of these can be used. Among these, Pt-coated Ti is preferred. When Pt-coated Ti is used, the insoluble Pt coats the Ti surface, resulting in an inert and insoluble cathode, and since metal ions do not leach from the cathode, there is no change in the composition of the cathode.

[0205] The shape of the cathode is not particularly limited, but it can be a rod, a ball, a disc, or a slab. If the cathode is a disc or a slab, it may have multiple through-holes, such as in a perforated metal plate or expanded metal plate. By having multiple through-holes, the surface area of ​​the cathode can be increased, and the electrolytic voltage can be kept low even at high current densities. The cathode may consist of one or more components.

[0206] (Catholite) The catholite is filled into the cathode chamber. Cassolite is used as the main component in plating solutions, although this is not limited to the above. It is preferable that the solution is an acidic anion containing the material. When used in combination with a tin methanesulfonate alloy plating solution, a tin methanesulfonate (MSA) solution is preferred for the cassolite. By using a solution of an acidic anion containing the material as the main component in the plating solution, even if a small amount of cassolite enters the plating solution from the diaphragm or seal, the impact on the plating solution can be minimized.

[0207] The catholite may substantially contain no ions of the same metal as the metal contained in the anode. The "metal contained in the anode" above may be the metal described above in the section on anodes. In this specification, "substantially contains no ions of the same metal as the metal contained in the anode" means that the concentration of ions of that metal is 0.1 g / L or less.

[0208] In this embodiment, gas can be blown into the catholite (bubbling) to stir it. This allows for a uniform concentration distribution of the catholite and a stabilization of the electrolytic voltage. The gas is not particularly limited and the same gas used to stir the anolite described above can be used. The gas can be used alone or in combination of two or more types. In addition to or instead of the above bubbling, other stirring methods such as paddle stirring or jet stirring can be used, and multiple stirring methods can also be used in combination.

[0209] In this embodiment, any one of the following combinations of anode, anolite, cathode, and catholite (1) to (3) can be adopted. (1) Anode: Sn pellet, Anolite: Mixed solution of tin methanesulfonate and MSA, Cathode: Pt-coated Ti mesh, Catholite: MSA solution (2) Anode: Cu ball, Anolite: Mixed solution of copper sulfate and sulfuric acid, Cathode: Pt-coated Ti mesh, Catholite: Sulfuric acid solution (3) Anode: Ni ball, Anolite: Mixed solution of nickel sulfamate and boric acid, Cathode: Pt coated Ti mesh, Castholite: Sulfamic acid solution

[0210] (First plating solution circulation chamber and second plating solution circulation chamber) The first and second plating solution circulation chambers are equipped with an outlet for discharging the plating solution to an electrolytic plating apparatus and an inlet for receiving the plating solution from the electrolytic plating apparatus, so that the plating solution can be circulated. The first and second plating solution circulation chambers are capable of containing the plating solution.

[0211] The first plating solution circulation chamber is defined by a first diaphragm and a second diaphragm, which will be described later. For example, the first plating solution circulation chamber may be a cell structure formed by a gasket or spacer sandwiched between the first diaphragm and the second diaphragm, which are supported by a frame.

[0212] The second plating solution circulation chamber is defined by a third diaphragm and a fourth diaphragm, which will be described later. For example, the second plating solution circulation chamber may be a cell structure formed by a gasket or spacer sandwiched between the third and fourth diaphragms, which are supported by a frame.

[0213] The capacities of the first and / or second plating solution circulation chambers are not particularly limited, and appropriate capacities can be selected according to the required metal ion supply rate (electrolysis rate per unit time). In particular, the first and / or second plating solution circulation chambers with the above cell structure are preferable because the width of the plating solution circulation chamber can be reduced to about 1 mm, and the capacity of the plating solution circulation chamber can be reduced.

[0214] In this embodiment, the volume of the first plating solution circulation chamber and / or the second plating solution circulation chamber can be reduced, thereby reducing the amount of plating solution remaining in the first and / or second plating solution circulation chambers. This reduces the amount of metal ions that enter the anode chamber from the first and / or second plating solution circulation chambers, and as a result, the above-mentioned a Passivation of the node surface can be suppressed. For example, by reducing the distance between the first diaphragm and the second diaphragm, the volume of the first plating solution circulation chamber and / or the second plating solution circulation chamber can be reduced.

[0215] The ratio of the volume of the plating solution circulation chamber (the sum of the volumes of the first and second plating solution circulation chambers) to the volume of the anode chamber (volume of the plating solution circulation chamber / volume of the anode chamber) is not particularly limited, but is preferably 0.005 to 0.5, more preferably 0.01 to 0.2, and most preferably 0.01 to 0.1. By keeping the above ratio within the above numerical range, passivation of the anode surface can be suppressed.

[0216] The flow rate when circulating the plating solution to the first and / or second plating solution circulation chambers is not particularly limited, and a flow rate can be selected that does not cause excessive changes in the concentration of the plating solution in the circulation chambers, depending on the required metal ion supply rate (electrolysis rate per unit time). On the other hand, when electrolysis is not performed, it is preferable to stop circulation or reduce the flow rate sufficiently in order to minimize ion diffusion through the first diaphragm. However, if circulation is stopped, there is a risk that crystals or the like may precipitate in the first and / or second plating solution circulation chambers due to compositional changes caused by ion diffusion through the first and third diaphragms. Therefore, if circulation is stopped for a certain period of time or longer, it is preferable to drain the plating solution from the first and / or second plating solution circulation chambers, or to periodically circulate the solution to replace the plating solution in the first and / or second plating solution circulation chambers.

[0217] (Plating solution) The metal ion supply system of this embodiment may further include a plating solution contained in the first plating solution circulation chamber and / or the second plating solution circulation chamber. The composition of the above plating solution can be appropriately set according to the metal to be plated in the electroplating apparatus. The composition of the plating solution is determined by the metal to be plated in the electroplating apparatus, and the combination of anode and anolite is determined according to the composition of the plating solution. The above plating solution may contain ions of the same metal as the metal contained in the anode. For example, if Sn is used as the metal of the anode, the plating solution will contain Sn 2+ It may contain ions. The metal included in the above anode can be the metal described above in the anode section.

[0218] The concentration of ions of the same metal as the metal contained in the anode in the plating solution is not particularly limited, and an appropriate concentration can be selected according to the type of metal to be plated, the specifications of the plating film, and the required uniformity of the plating film. For example, the concentration of ions of the same metal as the metal contained in the anode can be 10-200 g / L, 20-150 g / L, or 30-100 g / L. Excellent uniformity of the plating film is achieved when the concentration is within the above numerical range.

[0219] The plating solution is not particularly limited, but a tin alloy plating solution, a copper sulfate plating solution, or a nickel sulfamate plating solution can be used. Of these, the tin alloy plating solution is particularly suitable.

[0220] The plating solution circulating between the first and second plating solution circulation chambers and the electroplating apparatus may contain metal ions. These metal ions are not particularly limited, but may include Ag + Sn 2+ Cu 2+ , Bi 3+ Alternatively, combinations of two or more of these are possible. Among these, Ag + and Sn 2+ This combination can be particularly useful.

[0221] (First and third diaphragms) In this embodiment, the first diaphragm is made of the same material as the third diaphragm. The first and / or third diaphragm may be, but is not limited to, an ion exchange membrane or a neutral porous membrane. A cation exchange membrane can be used. Among these, an ion exchange membrane is preferred. The ion exchange membrane is not particularly limited, but a cation exchange membrane is preferred. By using a cation exchange membrane, metal ions contained in the anolite in the anode chamber can be transferred to the plating solution circulation chamber. A fluorine-based cation exchange membrane or a hydrocarbon-based cation exchange membrane can be used. Among these, a fluorine-based cation exchange membrane is preferred in that it has excellent durability as a diaphragm. In particular, when halide ions are contained in the anolite, the diaphragm tends to deteriorate easily, so a fluorine-based cation exchange membrane can be suitably used.

[0222] As for the fluorine-based cation exchange membranes mentioned above, commercially available products such as FORBLUE® Sx-2301 and Sx-1811 (both manufactured by AGC Inc.), Nafion® N424 and N438 (both manufactured by Chemours Company) can be used. As for hydrocarbon-based cation exchange membranes, commercially available products such as Celemion® CMVN (manufactured by AGC Inc.) and Neosepta® CSE (manufactured by Astrom Co., Ltd.) can be used.

[0223] The diffusion and osmosis rate of water in the first diaphragm is not particularly limited, but is 0.01 to 1 (mol / h·dm³). 2 (mol / L) is preferred, and 0.01 to 0.5 (mol / h·dm) is preferred. 2 (mol / L) is more preferable, and 0.01 to 0.2 (mol / h·dm) is preferred. 2 (mol / L) is the most preferred.

[0224] (Second or fourth diaphragm) In this embodiment, the second diaphragm is made of the same material as the fourth diaphragm. The second and / or fourth diaphragm is not particularly limited, but a hydrogen ion selective permeable membrane, a bipolar membrane, or a monovalent cation selective permeable membrane can be used. Of these, a hydrogen ion selective permeable membrane or a bipolar membrane is particularly preferred. By using a hydrogen ion selective permeable membrane or a bipolar membrane, it is possible to suppress metal ions in the plating solution from permeating through the second diaphragm and entering the cathode chamber.

[0225] As the hydrogen ion selective permeable membrane mentioned above, commercially available products such as Celemion® HSFN (manufactured by AGC Engineering Co., Ltd.) can be used. As the bipolar membrane mentioned above, commercially available products such as Neosepta® BP-1EX (manufactured by Astrom Co., Ltd.) can be used.

[0226] The diffusion and osmosis rate of water in the second diaphragm is not particularly limited, but is 0.1 to 5 (mol / h·dm³). 2 (mol / L) is preferred, and 0.2 to 3 (mol / h·dm) 2 (mol / L) is the most preferred.

[0227] In a metal ion supply system, it is preferable that the first and third diaphragms are cation exchange membranes, and the second and fourth diaphragms are hydrogen ion selective permeable membranes or bipolar membranes. This combination allows for the supply of metal ions to the plating solution with high current efficiency.

[0228] In the metal ion supply system, the diffusion and permeation rates of water in the second and fourth diaphragms may be greater than those of water in the first and third diaphragms. The difference between the diffusion and osmosis rates of water in the second and fourth diaphragms and the diffusion and osmosis rates of water in the first and third diaphragms is not particularly limited, but is greater than 0 and less than or equal to 5 (mol / h·dm 2 (mol / L) is preferred, and 0.1 to 3 (mol / h·dm) 2 (mol / L) is more preferable, and 0.2 to 2 (mol / h·dm) 2 (mol / l) is most preferred. The ratio of the diffusion rate of water in the second and fourth diaphragms to the diffusion rate of water in the first and third diaphragms (diffusion rate of water in the second and fourth diaphragms / diffusion rate of water in the first and third diaphragms) is not particularly limited, but is preferably greater than 1 and 100 or less, more preferably 3 to 50, and 5 to 30. Most preferable.

[0229] (One or more stacked modules) One or more stacked modules are positioned between the first plating solution circulation chamber and the cathode. Each of the one or more stacked modules includes an anolite chamber filled with anolite and a second plating solution circulation chamber defined by a third and a fourth diaphragm.

[0230] There may be one or more stacked modules. The number of stacked modules is not particularly limited, but 1 to 5 is preferred, 1 to 3 is more preferred, and 1 to 2 is most preferred. By keeping the number of stacked modules within the above numerical range, the structure is not too complex, the area of ​​the diaphragm used is minimized, and sludge generation in the anolite can be suppressed. In the examples in Figures 6 and 7, there is one stacked module.

[0231] (Anolite Room) The Anorite chamber can contain Anorite. The capacity of the anorite chamber is not particularly limited. The anolite chamber may not contain an anode.

[0232] The anolite filling the anolite chamber can be the same as the anolite filling the anode chamber described above. Preferably, the anolite chamber is connected to the anode chamber by piping or a circulation pump so that the anolite can be circulated. By circulating the anolite between the anode chamber and the anolite chamber, metal ions dissolved from the anode can be supplied to the anolite chamber, stabilizing the composition of the anolite in the anolite chamber and stirring the contents of the anolite chamber.

[0233] The flow rate when circulating the anolite between the anode chamber and the anolite chamber is not particularly limited; a flow rate should be selected that does not cause excessive changes in the concentration of the plating solution in the anolite chamber, depending on the required metal ion supply rate (electrolysis rate per unit time). On the other hand, when electrolysis is not being performed, it is preferable to stop the circulation or reduce the flow rate sufficiently in order to minimize ion diffusion through the first diaphragm.

[0234] (Other configurations) The metal ion supply system may further include an external power supply connected to the cathode and anode. Preferably, the external power supply is equipped with a reverse current prevention mechanism (such as a diode). By installing a reverse current prevention mechanism, it is possible to prevent reverse current from flowing and causing metal ions to move into the anolite when the system is stopped.

[0235] In this embodiment, the metal ion supply system may further include a reserve tank for circulating catholite between it and the cathode chamber. Furthermore, an oxygen-containing gas (such as air) can be blown into (bubbled) within the reserve tank. An example of the reserve tank is described below.

[0236] Figure 2 is an enlarged view of the area around the cathode chamber in the metal ion supply system. The metal ion supply system includes the cathode chamber 1300, the cathode 1700, the fourth diaphragm 2550, etc. In the metal ion supply system shown in Figure 2, a reserve tank 1310 is provided, which can circulate catholite between itself and the cathode chamber 1300.

[0237] Metal ions that have moved from the plating solution circulation chamber via the fourth diaphragm 2550 into the catholite n (Sn 2+ Small amounts of metal ions (such as Sn) may be present. These metal ions may precipitate on the cathode surface, and if such precipitation occurs, the electrolysis voltage will rise. By blowing an oxygen-containing gas into the reserve tank 1310, the above metal ions are oxidized, and the oxidized metal ions (Sn) are removed. 4+ (etc.) and the oxidized metal ions precipitate as hydroxides and can be removed by the filter. As a result, metal ions (Sn) that have moved from the plating solution circulation chamber can be removed. 2+ This can suppress the deposition of substances such as on the cathode surface, thereby preventing the aforementioned increase in electrolysis voltage.

[0238] In the metal ion supply system of this embodiment, the first plating solution circulation chamber and / or the second plating solution circulation chamber, which are located between the anode chamber and the cathode chamber, can have a structure similar to that of the cell structure of an electrodialysis machine. Specifically, as shown in Figure 3, the internal space of the gasket 1230 / spacer 1240 sandwiched between the first diaphragm 1400, which is supported by the frame 1110 and gasket 1120, and the second diaphragm 1500, which is supported by the frame 1320 and gasket 1330, can be used as the first plating solution circulation chamber.

[0239] Figure 3 shows the first diaphragm 1400 and the second diaphragm 1500, but these may be replaced with the third diaphragm and the fourth diaphragm, respectively. In this case, the internal space of the gasket 1230 / spacer 1240 sandwiched between the third diaphragm, which is supported by the frame 1110 and gasket 1120, and the fourth diaphragm, which is supported by the frame 1320 and gasket 1330, can be used as the second plating solution circulation chamber.

[0240] By adopting the structure described above, the volume of the first plating solution circulation chamber and / or the second plating solution circulation chamber can be minimized (to a width of approximately 1 mm). As a result, the effects of dilution and loss of the plating solution when replacing the contents of the plating solution circulation chamber with a liquid that substantially does not contain at least one of the metal ions described later can be minimized.

[0241] In the metal ion supply system of this embodiment, the first plating solution circulation chamber may be a space defined by a first diaphragm and a second diaphragm, respectively, supported by a frame. The second plating solution circulation chamber may be a space defined by a third diaphragm and a fourth diaphragm, respectively, supported by a frame.

[0242] In the metal ion supply system of this embodiment (third embodiment), the metal ion supply method to an electroplating apparatus, which includes the step of supplying metal ions (i) and the step of not supplying metal ions (ii) of the second embodiment, can be applied. In this case, the first plating solution circulation chamber and the second plating solution circulation chamber can be used as the plating solution circulation chamber. As described above, in step (ii), the step in which metal ions are not supplied, by replacing the first plating solution circulation chamber and the second plating solution circulation chamber with a liquid that substantially does not contain at least one of the metal ions supplied to the electroplating apparatus, the passivation of the anode surface caused by metal ions mixed in from the first plating solution circulation chamber and the second plating solution circulation chamber can be suppressed in the metal ion supply system of this embodiment (third embodiment).

[0243] The metal ion supply system is a system for supplying metal ions to the electroplating apparatus. The electroplating apparatus can be the same as the electroplating apparatus described in "1. First Embodiment" above.

[0244] The first to third embodiments described above can be combined in any combination of two or more of them. [Examples]

[0245] The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Test Examples 1 to 6, described later, are test examples corresponding to the first embodiment described above.

[0246] [Test Example 1] Metal ions (Cu) in a metal ion supply system using a 3-chamber cell (equipped with an anode chamber, first diaphragm, plating solution circulation chamber, second diaphragm, and cathode chamber in this order) 2+ The following studies were conducted to verify the supply performance of ). • Voltage stability during continuous electrolysis • pH change during continuous electrolysis and non-electrolysis • Changes in the concentration of inorganic components during continuous electrolysis and non-electrolysis. The three-chamber cell used is shown in Figure 8. The electrolytes used (castholite, plating solution, anolite), electrodes and diaphragms, electrolysis conditions, and the evaluations performed are shown in Table 2 below. In Test Example 1, the osmolality of the plating solution and the osmolality of the catholite were not adjusted, and Test Example 1 corresponds to a comparative example of the first embodiment described above. At the start of the test, the osmolality of the plating solution was approximately 3.4 mol / L, and the osmolality of the catholite was approximately 2.1 mol / L.

[0247] [Table 2]

[0248] Furthermore, the details of the measurement method for the "Evaluation" item in Table 2 above are shown below. [Measurement of anode and cathode weights before and after testing] After the electrolysis test, the anode and cathode were removed from the test cell, washed with water, and dried. Their weights were then measured using an electronic balance. For each of the anode and cathode, the difference between the weight before and after the test was calculated and recorded as the weight change. [Changes in the volume of anolite, plating solution, and catholite solution before and after the test] After the electrolytic test, the anolite, plating solution, and catholite were recovered from the test cell as much as possible, and the volume of each liquid was measured using a graduated cylinder. [Analysis of the liquid before and after the test] • Sulfuric acid concentration: Samplings of the anolite, plating solution, and castholite were taken before and after the electrolysis test, and the concentration was determined by acid-base titration using a sodium hydroxide solution. • Cu concentration: The anolite, plating solution, and catholite were sampled before and after the electrolysis test, and the absorbance was measured using a spectrophotometer (wavelength: 810 nm) with solutions that were precisely diluted 50 times with pure water to determine the Cu concentration. Using the sulfuric acid concentration and Cu concentration obtained as described above, along with the volumes of anolite, plating solution, and catholite measured above, the amounts of Cu and sulfuric acid (amount of substance) in each solution were determined. [Voltage stability during electrolysis] A voltage logger was used to monitor the anode-cathode voltage during the electrolysis test.

[0249] The results are shown in Figures 9-12. Figure 9 shows Cu in anolite, plating solution, or catholite during testing. 2+ These are graphs showing the change in volume (moles). Figure 10 is a graph showing the change in the volume (liters) of each solution (anolite, plating solution, or catholite) during the test. Figure 11 is a graph showing the change in pH of the anolite during the test. Figure 12 is a photograph showing the appearance of the cathode after the test. In Figures 9-11, "6ASD" indicates the case where a voltage is applied at a current density of 6ASD, and "0ASD" indicates the case where each solution is simply stirred without applying voltage. During the test, the osmolality of the plating solution is always greater than the osmolality of the catholite.

[0250] As can be seen from the graph in Figure 9 (B), the Cu in the plating solution in the plating solution circulation chamber is affected by electrolysis. 2+ The amount increased. As a result, the three-chamber cell contained metal ions (Cu 2+ )It was confirmed that it functions as a supply system. As can be seen from the graphs (A) and (C) in Figure 9, Cu in anolite and catholite 2+ No significant changes were observed in the quantity. On the other hand, as can be seen from the graphs (A) and (B) in Figure 10, electrolysis increased the volume of the plating solution in the plating solution circulation chamber and decreased the volume of anolite in the anode chamber. From these results, Cu 2+ It is presumed that electroosmosis of water from the anolite to the plating solution occurred as the anolite moved, resulting in the dilution of the plating solution with water. Dilution of the plating solution in the plating solution circulation chamber is undesirable because it alters the composition of the plating solution supplied to the electroplating apparatus.

[0251] [Test Example 2] To examine the three-chamber cell of Test Example 1 in more detail, an electrolytic test was conducted in the same manner as in Test Example 1, except that the osmolality of the cassolite was changed. In addition, a simulation of the electrolytic test was performed for the three-chamber cell under conditions where the osmolality of the cassolite was changed. A personal computer equipped with spreadsheet software (Microsoft Excel®) was used for the simulation. In the simulation, the amount of electroosmotic water permeating through the membrane was assumed to be proportional to the amount of ions that permeated through the membrane, and the amount of permeating water by diffusion was calculated to be proportional to the difference in osmolality of the liquids on both sides of the membrane.

[0252] In the electrolytic tests and simulations, the osmolality of the plating solution was set to approximately 3.4 mol / L, and the current density was set to 6ASD. The diaphragm parameters used in the simulation are shown in Tables 3 and 4 below. Table 3 k w As can be seen from the values, the HSFN membrane (second membrane) is set to have a higher water diffusion and infiltration rate compared to the Sx-2301 membrane (first membrane).

[0253] [Table 3]

[0254] [Table 4]

[0255] The results of the electrolytic tests and simulations are shown in Figures 13-18. Figure 13 shows the Cu when the concentration of cassolite (H2SO4) is 100 g / L. 2+Alternatively, this is a graph showing the change in the concentration (g / L) of H2SO4. Figure 14 is a graph showing the change in the volume (L) of each solution (anolite, plating solution, catholite) when the concentration of catholite is 100 g / L. When the concentration of catholite is 100 g / L, the osmolality of catholite is approximately 2.1 mol / L. During the electrolytic tests and simulations in Figures 13 and 14, the osmolality of the plating solution is always greater than the osmolality of catholite, which corresponds to the comparative example of the first embodiment described above.

[0256] Figure 15 shows the Cu when the catholite concentration is 230 g / L. 2+ Alternatively, this is a graph showing the change in the concentration (g / L) of H2SO4. Figure 16 is a graph showing the change in the volume (L) of each solution (anolite, plating solution, catholite) when the concentration of catholite is 230 g / L. When the concentration of catholite is 230 g / L, the osmolality of catholite is approximately 4.7 mol / L. During the electrolytic tests and simulations in Figures 15 and 16, the osmolality of catholite is always greater than the osmolality of the plating solution, which corresponds to the example of the first embodiment described above.

[0257] Figure 17 shows the Cu when the concentration of cassolite is 300 g / L. 2+ Alternatively, this is a graph showing the change in the concentration (g / L) of H2SO4. Figure 18 is a graph showing the change in the volume (L) of each solution (anolite, plating solution, catholite) when the concentration of catholite is 300 g / L. When the concentration of catholite is 300 g / L, the osmolality of catholite is approximately 6.3 mol / L. During the electrolytic tests and simulations in Figures 17 and 18, the osmolality of catholite is always greater than the osmolality of the plating solution, which corresponds to the example of the first embodiment described above.

[0258] In Figures 13-18, the solid or dotted lines related to "Anolyte," "Cathlyte," or "Plating sol." represent the simulation results. The plots (circles, triangles, or squares) related to "Anolyte experiment," "Cathlyte experiment," or "Plating sol. experiment" in Figures 13-18 represent the results of actual electrolytic tests conducted in the same manner as in Test Example 1.

[0259] The results shown in Figures 13-18 demonstrate that the results of the actual electrolysis tests and the simulations match well, indicating that the electrolysis tests can be adequately reproduced through simulation.

[0260] In the electrolytic tests and simulations shown in Figures 13 and 14, the osmolality of the catholite (at the start of the test: approximately 2.1 mol / L) is lower than the osmolality of the plating solution (at the start of the test: approximately 3.4 mol / L). From the graph in Figure 13(B), the Cu concentration in the plating solution increases over time. 2+ The concentration of Cu is increasing in the plating solution. 2+ It was found that a sufficient supply of the solution was available. On the other hand, the graph in Figure 14 shows that the amount of plating solution increased over time, indicating that dilution by water was progressing. When the plating solution is diluted, it cannot be used for electroplating as is, and it becomes necessary to discard it and add a new plating solution, which leads to an increase in the cost of the plating process.

[0261] In the electrolytic tests and simulations shown in Figures 15 and 16, the osmolality of the catholite (at the start of the test: approximately 4.7 mol / L) is greater than the osmolality of the plating solution (at the start of the test: approximately 3.4 mol / L). From the graph in Figure 15(B), the Cu concentration in the plating solution increases over time. 2+ The concentration of is increasing, and Cu is in the plating solution. 2+It was found that a sufficient supply of the plating solution was available. Furthermore, the graph in Figure 16 shows that the amount of plating solution remained constant even as time passed, indicating that no dilution by water occurred. By maintaining a constant amount of plating solution in this way, adjustment of the plating solution becomes unnecessary, enabling continuous plating.

[0262] In the electrolytic tests and simulations shown in Figures 17 and 18, the osmolality of the catholite (at the start of the test: approximately 6.3 mol / L) is greater than the osmolality of the plating solution (at the start of the test: approximately 3.4 mol / L). From the graph in Figure 17(B), the Cu concentration in the plating solution increases over time. 2+ The concentration of is increasing, and Cu is in the plating solution. 2+ It was found that a sufficient supply of the plating solution was being provided. From the graph in Figure 18, it was found that the amount of plating solution decreased over time, indicating that the plating solution was becoming concentrated. When such concentration of the plating solution occurs, the amount of plating solution can be easily adjusted by adding water to the plating solution circulation chamber from the outside, so the concentration of the plating solution can be adequately addressed. On the other hand, the dilution of the plating solution as shown in Figure 14 is difficult to address because such adjustments are not possible.

[0263] [Test Example 3] As a mass-producible device, a metal ion supply system using a three-chamber cell (equipped with an anode chamber, a first diaphragm, a plating solution circulation chamber, a second diaphragm, and a cathode chamber in that order), as described later, was selected, and an electrolytic test simulation was performed. For the simulation, a personal computer equipped with spreadsheet software (Microsoft Excel®) was used, as in Test Example 2. In the simulation, the osmolality of the plating solution was set to approximately 3.4 mol / L, and the osmolality of the catholite was set to approximately 4.7 mol / L. During the simulation, the osmolality of the catholite was always greater than the osmolality of the plating solution, which corresponds to the example of the first embodiment described above. The diaphragm parameters used in the simulation were the same as those in Tables 3 and 4 of Test Example 2 described above. Table 5 below shows the plating solution, electrodes / diaphragm, and plating conditions set in the simulation. As shown in Table 5, during the electrolysis test, when the amount of anolite (DIW (ultrapure water)) in the anode chamber decreased by 1.25 L, the system was set to supply (feed) 1.25 L of anolite to replenish it. Also, when the amount of catholite (H2SO4 solution) in the cathode chamber increased by 0.5 L, the system was set to drain (bleed) 0.68 L of catholite and supply 0.18 L of catholite to remove it.

[0264] [Table 5]

[0265] The simulation results are shown in Figures 19 and 20. Figure 19 shows Cu 2+ Alternatively, Figure 20 is a graph showing the change in the concentration (g / L) of H2SO4. Figure 20 is a graph showing the change in the volume (L) of each solution (anolite, plating solution, catholite).

[0266] From the graph in Figure 19 (B), regardless of the passage of time, Cu in the plating solution 2+ The concentration of the metal ion was maintained at a sufficient level and was found to function adequately as a metal ion supply system. Furthermore, the graph in Figure 20 shows that the amount of plating solution remained constant even as time passed, indicating that no dilution by water occurred. Maintaining a constant amount of plating solution in this way eliminates the need for adjustment of the plating solution, enabling continuous plating. Moreover, the graph in Figure 20 shows that by simultaneously adding anolite to the anode chamber and removing catholite from the cathode chamber, the amounts of both anolite and catholite were maintained at a constant level, enabling continuous operation without stopping the system. These results indicate that, even in mass-production equipment, it is important to make the osmolality of the catholite greater than that of the plating solution.

[0267] [Test Example 4] A metal ion supply system was prepared using a three-chamber cell (equipped with an anode chamber, a first diaphragm, a plating solution circulation chamber, a second diaphragm, and a cathode chamber in that order). The stability of the plating solution composition was then confirmed when metal ions were supplied to the plating solution in a plating tank using an insoluble anode using the above metal ion supply system.

[0268] Figure 21 is a cross-sectional view of the overall configuration of the three-chamber cell 2100 and the plating cell (plating tank) 10 used.

[0269] The first diaphragm 1400 and the second diaphragm 1500 of the 3-chamber cell 2100 used the same membrane as in Test Example 1 above. The opening area of ​​both the first diaphragm 1400 and the second diaphragm 1500 was 0.374 dm². 2 The width of the plating solution circulation chamber (distance between the first diaphragm 1400 and the second diaphragm 1500) was 8 mm, and the internal volume of the plating solution circulation chamber was 30 ml. A cathode 1700 (using a Pt / Ti lath electrode) was placed in the cathode chamber of the 3-chamber cell 2100, and an anode case 1610 (made of Ti lath) containing approximately 150 g of anode 1600 (using a Cu ball (containing phosphorus copper, 12 mm in diameter)) was placed in the anode chamber. In addition, 300 ml of cassolite (sulfuric acid solution, concentration: 233 g / L, osmolality: 4.8 mol / L) was placed in the cathode chamber of the 3-chamber cell 2100, and 300 ml of anolite (copper sulfate solution, Cu concentration: 50 g / L, pH: 3.3) was placed in the anode chamber.

[0270] Plating cell 10 uses an anode electrode AN (an insoluble anode (IrO2 / Ti lath electrode)). The substrate (substrate to be plated) W (a Cu-coated substrate was used) was placed in the casing, and 900 ml of copper sulfate plating solution (Cu concentration: 50 g / L, sulfuric acid concentration: 100 g / L, chlorine concentration: 50 mg / L, osmolality: 3.3 mol / L) was added.

[0271] While stirring with a paddle 15 in the plating cell 10, a voltage was applied between the substrate W to be plated and the insoluble anode AN of the plating cell 10 using a stabilized power supply, and the plating process was performed at a current of 2.14 A for 6 hours. Simultaneously with this plating process, a voltage was applied between the anode 1600 and cathode 1700 of the three-chamber cell 2100 using another stabilized power supply, and electrolysis was performed at a current of 2.14 A for 6 hours. During electrolysis, the plating solution was circulated at a flow rate of 0.21 / min between the plating solution circulation chamber of the three-chamber cell 2100 and the plating cell 10 using a liquid transfer pump, and the anolite was stirred (air stirring) by supplying gas 1850 (air was used) to the anode chamber (air flow rate: 1 L / min).

[0272] Two and four hours after the start of plating and electrolytic treatment, the following adjustments were made to the anolite and catholite in the 3-chamber cell 2100. • Anolite: Because the liquid level decreased (liquid volume decreased), pure water was supplied until the liquid level returned to the level at the start of electrolysis. • Castholite: As the liquid level rose (liquid volume increased), it was assumed that the castholite had been diluted by the permeating water. A portion of the castholite was removed, and a 47 g / L sulfuric acid solution was added to adjust the concentration and liquid volume. At this time, the amount of castholite removed and the amount of sulfuric acid added were calculated and adjusted to match the concentration and water level at the start of electrolysis.

[0273] After the plating and electrolytic treatment were completed, the plating solution was recovered as much as possible, and the volume was measured using a graduated cylinder. The sulfuric acid and Cu concentrations of the plating solution and cassolite were also measured before and after the test using the same method as in Test Example 1. The osmolality was calculated from the measurement results, and the average osmolality was calculated from the osmolality before and after the test. The difference between the average osmolality of the cassolite and the average osmolality of the plating solution was also calculated. The results are shown in Table 6.

[0274] [Test Examples 5, 6, Comparative Example 1] The plating and electrolytic tests were conducted in the same manner as in Test Example 4, except that the sulfuric acid concentration of the catholite at the start of the plating and electrolytic treatment was changed to the concentration shown in Table 6. The results are shown in Table 6.

[0275] [Comparative Example 2] Except for not supplying metal ions using the 3-chamber cell 2100, the same plating cell 10 as in Test Example 4 was used, and the plating test was conducted in the same manner as in Test Example 4. The results are shown in Table 6.

[0276] [Table 6]

[0277] In Test Examples 4-6, the average osmolality of the catholite is higher than the average osmolality of the plating solution. Therefore, as shown in Table 6, in Test Examples 4-6, the dilution of the plating solution is suppressed compared to Comparative Example 1, where the average osmolality of the catholite is lower than the average osmolality of the plating solution. Yes, they are. Furthermore, in Comparative Example 2, where Cu ion supply using the 3-chamber cell 2100 was not performed, the Cu concentration of the plating solution decreased significantly and the sulfuric acid concentration increased significantly after the test. On the other hand, in Test Examples 4-6, where Cu ion supply using the 3-chamber cell 2100 was performed, the changes in Cu concentration and sulfuric acid concentration in the plating solution before and after the test were relatively small, and the composition of the plating solution was stable.

[0278] From these results, it was found that in a metal ion supply system, the dilution of the plating solution in the plating solution circulation chamber can be suppressed by making the osmolality of the catholite greater than the osmolality of the plating solution. [Explanation of symbols]

[0279] 10…Plating tank (plating cell) 11... Circuit board holder 12…Anode Unit 13… Anode box 13a...diaphragm 14…Regulation Plate 15…Paddle 16...Outer tank W... Circuit board AN... Anode electrode 200... Anode holder 300... Anode mask 700...Circulation mechanism 702... Circulation line 704... valve 706... Pump 708...Temperature control device 710... Filter 1100... Anode Room 1110...frame 1120... Gasket 1200... Plating solution circulation chamber 1210...exit 1220…Entrance 1230... Gasket 1240... Spacer 1250... Gas supply unit 1260... A liquid supply unit that substantially does not contain at least one of the metal ions. 1270, 1280... Connection to the waste tank V1, V2, V3, V4, V5, V6, V7… valves 1300... Cathode chamber 1310... Reserve tank 1320...frame 1330... Gasket 1400…1st diaphragm 1500…Second diaphragm 1600... Anode 1610... Anode case 1700... Cathode 1800…Diffuser pipe 1850...gas 1900…External power supply 2000…Metal ion supply system 2100...3-room cell 2200...First plating solution circulation chamber 2210...exit 2220…Entrance 2400…First diaphragm 2450…Second diaphragm 2500…Third diaphragm 2550…4th diaphragm 2800…Stackable module 2810... Anolite Room 2811...Exit 2812...Entrance 2813, 2814… Piping 2820...Second plating solution circulation chamber 2821...Exit 2822…Entrance 2950... Nitrogen 3000…Metal ion supply system

Claims

1. A metal ion supply system for an electroplating apparatus, Anode chamber, Anode installed in the aforementioned anode chamber, Cathode chamber, The cathode installed in the aforementioned cathode chamber, A plating solution circulation chamber is located between the anode chamber and the cathode chamber. A first diaphragm is disposed between the anode chamber and the plating solution circulation chamber, and A second diaphragm is positioned between the cathode chamber and the plating solution circulation chamber. Equipped with, The plating solution circulation chamber includes an outlet for discharging the plating solution to an electrolytic plating apparatus and an inlet for receiving the plating solution from the electrolytic plating apparatus, so that the plating solution can be circulated. The second diaphragm has a water diffusion and permeation rate that is greater than the water diffusion and permeation rate of the first diaphragm. The anode chamber is filled with an anolite containing ions of the same metal as the metal contained in the anode. The cathode chamber is filled with catholite. The metal ion supply system wherein the catholite has a higher osmolality than the osmolality of the plating solution in the plating solution circulation chamber.

2. The metal ion supply system according to claim 1, wherein the anode is a soluble anode.

3. The metal ion supply system according to claim 1 or 2, wherein the first diaphragm is a cation exchange membrane and the second diaphragm is a hydrogen ion selective permeable membrane or a bipolar membrane.

4. A method for supplying metal ions to an electrolytic plating apparatus, (i) A step of circulating a plating solution containing metal ions between a plating solution circulation chamber and an electrolytic plating apparatus to supply the metal ions to the electrolytic plating apparatus, and (ii) A step in which the metal ions are not supplied to the electroplating apparatus, wherein the plating solution circulation chamber is replaced with a liquid that substantially does not contain at least one of the metal ions. The method for supplying metal ions, including the aforementioned method.

5. The metal ion supply method according to claim 4, further comprising the step of discharging a liquid in the plating solution circulation chamber that substantially does not contain at least one of the plating solution or the metal ions to an outside other than the electrolytic plating apparatus when switching between the step (i) supplying metal ions and the step (ii) not supplying metal ions.

6. The metal ion supply method according to claim 4, further comprising the step of stopping the operation of the plating solution circulation chamber and discharging the liquid in the plating solution circulation chamber that substantially does not contain at least one of the plating solution or the metal ions to an outside other than the electrolytic plating apparatus when switching between step (i) supplying metal ions and step (ii) not supplying metal ions.

7. The metal ion supply method according to any one of claims 4 to 6, wherein the plating solution circulation chamber is located between the anode chamber and the cathode chamber, using a metal ion supply system.

8. A method for supplying metal ions according to any one of claims 4 to 6, performed using the metal ion supply system described in claim 1.

9. A metal ion supply system for an electroplating apparatus, An anode chamber containing an anode and filled with anolite, A cathode chamber containing a cathode and filled with catholite, A first plating solution circulation chamber is defined by a first diaphragm and a second diaphragm and is located between the anode chamber and the cathode chamber, and One or more laminated modules disposed between the first plating solution circulation chamber and the cathode, each comprising an anolite chamber filled with anolite and a second plating solution circulation chamber defined by a third diaphragm and a fourth diaphragm, Equipped with, The third diaphragm is made of the same material as the first diaphragm, and the fourth diaphragm is made of the same material as the second diaphragm. The first plating solution circulation chamber and the second plating solution circulation chamber each include an outlet for discharging the plating solution to an electrolytic plating apparatus and an inlet for receiving the plating solution from the electrolytic plating apparatus, respectively, so that the plating solution can be circulated. The metal ion supply system comprises an anorite chamber having an outlet for discharging anorite from the anorite chamber and an inlet for receiving anorite into the anorite chamber, so as to enable fluid communication between the anorite in the anode chamber and the anorite in the anorite chamber.

10. The metal ion supply system according to claim 9, wherein the first and third diaphragms are cation exchange membranes, and the second and fourth diaphragms are hydrogen ion selective permeable membranes or bipolar membranes.

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