Method for removing organic agents contained in used plating solution and method for regenerating plating solution

Abstract

The purpose of the present invention is to provide a method for removing an organic agent (organic additive and decomposition product thereof) from a used plating liquid by a technique that is easier and simpler, and a method for regenerating a plating liquid. In order to achieve this purpose, the present invention employs a method for removing an organic agent contained in a plating liquid, characterized by introducing ozone bubbles into a used plating liquid after a plating operation and oxidatively decomposing the organic agent. In addition, the present invention employs a method for regenerating a plating liquid, characterized by performing a UV radiation process or a heating process on the organic-agent-removed plating liquid from which a residual organic agent has been removed using the above method, and removing the ozone bubbles remaining in the solution to produce a regenerated plating liquid.

Description

[Technical Field]

[0001] The present application relates to a method for removing "organic additives and their decomposition products" (hereinafter referred to as "organic agents") contained in a used plating solution, and a method for regenerating the plating solution. [Background technology]

[0002] The solution used to form a plating film (hereinafter referred to as "plating solution") contains various organic additives for the purposes of improving plating efficiency and the solution stability of the plating solution. These organic additives may decompose when they come into contact with the electroplating electrode during plating operations or when plating is performed at relatively high temperatures. Furthermore, when an initially prepared plating solution is used multiple times, some of the organic additives deteriorate and change into compounds with smaller molecular weights. The decomposition products thus produced become organic impurities that no longer function as organic additives.

[0003] While it is possible to restore a plating solution to a good condition by replenishing the organic additives lost due to decomposition or degradation, the presence of such decomposition products in the plating solution may hinder the deposition of a good plating film. Furthermore, analyzing the components of used plating solutions to measure the amount of deficient organic additives can produce complex analysis results, making it difficult to accurately determine the remaining amount of organic additives. Therefore, currently, used plating solutions are periodically discarded and replaced, which increases the manufacturing costs of plated products. Furthermore, when treating used plating solutions for wastewater treatment, organic additives must be removed from the plating solution to meet wastewater standards. For these reasons, a simple and reliable method for removing organic additives from used plating solutions and a method for regenerating plating solutions are needed.

[0004] In order to address the above-mentioned problems, Patent Document 1 discloses a "method for regenerating a metal plating solution, characterized by contacting the metal plating solution with polyolefin fibers and / or a fiber structure containing polyolefin fibers to remove organic impurities from the metal plating solution."

[0005] Patent Document 2 discloses a "method for regenerating a copper plating solution, which comprises the steps of: removing organic matter from the copper plating solution by adsorption with activated carbon; and passing the solution through a reverse osmosis membrane having a permeability of 80% or more for sodium sulfate and sodium formate and a permeability of 20% or less for copper and chelate compounds."

[0006] As described above, attempts have been made to eliminate wasteful use of resources by recycling plating solutions and to reduce the manufacturing costs of plated products. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2017-179604 [Patent Document 2] Japanese Patent Application Publication No. 4-99199 Summary of the Invention [Problem to be solved by the invention]

[0008] However, conventional methods for removing organic agents from plating solutions mainly utilize physical adsorption methods, such as the use of "polyolefin fibers and / or fiber structures containing polyolefin fibers" in Patent Document 1 and the use of "activated carbon" in Patent Document 2.

[0009] In such physical adsorption methods, the adsorption and removal process and the removal device used therein are complex in structure, and the removal device tends to be large. In addition, the adsorption efficiency may vary depending on the state of the adsorbent. Furthermore, there are problems such as fluctuations in the removal efficiency of organic substances remaining in the plating solution due to variations in the contact state between the plating solution and the adsorbent.

[0010] In view of these problems, the present application aims to provide a method for removing organic agents from a used plating solution and a method for regenerating the plating solution using a simpler and more convenient technique. [Means for solving the problem]

[0011] Therefore, in order to achieve the above-mentioned object, as a result of intensive research, the inventors have come up with the following "method for removing organic agents contained in a plating solution" and "method for regenerating a plating solution."

[0012] A. Methods for removing organic substances contained in plating solutions The method for removing organic agents contained in a plating solution according to the present application is a method for removing residual organic agents in a used plating solution after a plating operation, and is characterized by introducing ozone bubbles into the used plating solution to oxidatively decompose the organic agents.

[0013] The method for removing organic agents contained in a plating solution according to the present application preferably uses ozone bubbles with an average bubble diameter of 20 nm to 3 mm. However, in the present invention, bubbles with an average bubble diameter of 0.5 mm to 3 mm are defined as ozone normal bubbles, and bubbles with an average bubble diameter of 20 nm to 500 nm are defined as ozone nanobubbles.

[0014] In the method for removing organic agents contained in a plating solution according to the present application, when ozone normal bubbles are used, it is preferable to introduce the ozone into the used plating solution so that the ozone concentration is 50 ppm to 300 ppm.

[0015] In the method for removing an organic agent contained in a plating solution according to the present application, when ozone nanobubbles are used, the ozone is preferably introduced into the used plating solution so that the ozone concentration is 2 ppm to 40 ppm.

[0016] In the method for removing organic agents contained in a plating solution according to the present application, the oxidative decomposition is preferably carried out by contacting the used plating solution with ozone normal bubbles for 0.5 to 3.5 hours when the ozone concentration of the ozone normal bubbles is 50 ppm to 300 ppm.

[0017] In the method for removing an organic agent contained in a plating solution according to the present application, the oxidative decomposition is preferably carried out by contacting the used plating solution with the ozone nanobubbles for 0.5 to 3.5 hours when the ozone concentration of the ozone nanobubbles is 2 ppm to 40 ppm.

[0018] The method for removing an organic agent contained in a plating solution according to the present application is preferably used for one selected from the group consisting of a copper sulfate-based plating solution, a nickel sulfate-based plating solution, and a cobalt sulfate-based plating solution.

[0019] B. How to regenerate plating solution The method for regenerating a plating solution according to the present application is a method for regenerating an organic-agent-removed plating solution after the removal of the remaining organic agents in the above-described method for removing organic agents contained in the plating solution, and involves subjecting the organic-agent-removed plating solution to ultraviolet irradiation treatment or heat treatment in which the solution is heated to 80°C to 95°C and left for 15 to 30 minutes to remove ozone bubbles remaining in the solution, thereby producing a regenerated plating solution.

[0020] In the method for regenerating a plating solution according to the present application, it is preferable to remove organic agents that cannot be decomposed by ozone by an adsorption method.

[0021] In the plating solution regeneration method according to the present application, it is preferable to analyze the organic additives remaining in the plating solution after completion of the ultraviolet irradiation treatment or heat treatment, and adjust the amount of organic additives necessary for the plating operation. [Effects of the Invention]

[0022] The method for removing organic agents contained in plating solutions according to the present invention makes it possible to easily and conveniently remove residual organic agents from used plating solutions through simplified processes. Furthermore, when regenerating plating solutions, residual ozone bubbles that affect the properties of the plating solutions can be easily and reliably removed by ultraviolet irradiation or heat treatment, which has the advantage of not affecting the efficiency of regeneration of the plating solutions. [Brief explanation of the drawings]

[0023] [Figure 1] This is a conceptual diagram of an apparatus for introducing ozone normal bubbles into used plating solution to oxidatively decompose remaining organic compounds. [Figure 2] FIG. 1 is a conceptual diagram of an apparatus for introducing ozone nanobubbles into a used plating solution to oxidatively decompose residual organic compounds. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, the embodiments for carrying out the invention will be explained separately as "embodiments of a method for removing an organic agent contained in a plating solution" and "embodiments of a method for regenerating a plating solution."

[0025] A. Methods for removing organic substances contained in plating solutions The method for removing organic agents contained in a plating solution according to the present application is a method for removing residual organic agents in a used plating solution after a plating operation, and is characterized by introducing ozone bubbles into the used plating solution to oxidatively decompose the residual organic agents.

[0026] Target plating solution: Any sulfuric acid-based plating solution can be used without any particular limitations. Examples include copper sulfate-based plating solutions containing copper sulfate as a component, nickel sulfate-based plating solutions containing nickel sulfate as a component, and cobalt sulfate-based plating solutions containing cobalt sulfate as a component. The plating solution may be used in either an electrolytic or electroless method. There are also no particular limitations on the metal concentration, organic agent content, etc., of the plating solution.

[0027] However, it is extremely useful to apply the organic agent removal method of the present application to copper sulfate-based plating solutions and nickel sulfate-based plating solutions, because it is suitable for decomposing and removing the organic additives that are usually contained in these solutions, and the regeneration method described below is particularly easy to apply.

[0028] Oxidatively decomposable organic agents: In the present application, organic agents that can be oxidatively decomposed by ozone bubbles are organic additives and their decomposition products, such as bis(3-sulfopropyl)disulfide (SPS), which is used as a deposition accelerator in copper sulfate-based plating solutions, and Janus Green B (JGB), which is used as a leveling agent. On the other hand, polyethylene glycol (PEG), which has an average molecular weight of about 2000 to 3000 and is used as a deposition inhibitor in copper sulfate-based plating solutions, and its decomposition products (in this case, polyethylene glycol that has deteriorated and become lower molecular weight due to use of the plating solution), have extremely stable structures in aqueous solutions and are therefore difficult to decompose with ozone. Furthermore, saccharin, which is used as a brightener and stress reliever in nickel sulfate-based plating solutions, and PEG, which is used as a brightener for the plating film surface, are also oxidatively decomposable organic agents. 2-Butyne-1,4-diol , sodium lauryl sulfate used as a pitting prevention agent, 2,5-dimethyl-3-hexyl benzoate used as a pitting prevention agent or brightener S N-2,5 - Diol, 3,6-dimethyl-4-octyne-3,6 - Diol, 3-hexyne-2,5 - Diol, Propargyl Alcohol, 2,4-Hexadiyn-1,6 - Diol, acetylene, 3,5-dimethyl-1-hexyne-3- ol, 2-methyl-3-butyne-2 - ol, 3-methyl-1-pentyne-3 - The method of the present application using ozone bubbles can also be used to oxidatively decompose organic compounds such as phenol, acetylenedicarboxylic acid, thiourea, and their decomposition products. The method of the present application can oxidatively decompose these organic compounds and separate and remove them as carbon dioxide gas, carbon, carbides, sulfur, etc. by vaporization or precipitation.

[0029] Ozone bubbles: There are no particular limitations on the method of introducing ozone bubbles into used plating solutions, as long as it can oxidize and decompose remaining organic compounds. For example, diffuser plates, diffuser pipes, etc. can be used. Organic additives in plating solutions can be oxidized and decomposed by contact with the anode, the electrode used in electroplating, or by plating at relatively high temperatures of 30°C or higher. Furthermore, when an initially prepared plating solution is used multiple times, some organic additives deteriorate and change into compounds with smaller molecular weights. Introducing ozone bubbles into used plating solutions decomposes the organic additives, such as the deposition accelerators, leveling agents, and pitting inhibitors, and their decomposition products with ozone, allowing the concentration of organic additives to be adjusted to normal levels afterward.

[0030] In the present application, it is preferable to use ozone bubbles with an average bubble diameter of 20 nm to 3 mm. However, in the invention of the present application, ozone normal bubbles are defined as those with an average bubble diameter of 0.5 mm to 3 mm, and ozone nanobubbles are defined as those with an average bubble diameter of 20 nm to 500 nm. Here, the lower limit of the average bubble diameter of ozone normal bubbles is set to 0.5 mm, but there is no particular limitation on the lower limit. However, this is defined as a value that allows ozone normal bubbles to be easily generated using a diffuser plate, diffuser tube, etc. On the other hand, if the average bubble diameter of ozone normal bubbles exceeds 3 mm, the specific surface area of ​​the ozone normal bubbles becomes too small, resulting in insufficient contact between the ozone normal bubbles and organic agents contained in the used plating solution, which tends to result in the oxidative decomposition effect of ozone being insufficient, and this is undesirable.

[0031] In the present application, it is also preferable to use ozone nanobubbles with an average bubble diameter of 20 nm to 500 nm as the ozone bubbles. Although the lower limit of the average bubble diameter of ozone nanobubbles is set to 20 nm, there is no particular limitation on the lower limit. However, this is set as a value that can be accurately detected and confirmed when ozone nanobubbles are generated. On the other hand, if the average bubble diameter of ozone nanobubbles exceeds 500 nm, it is not preferable because it will not be possible to obtain a significantly higher oxidative decomposition ability compared to the above-mentioned normal ozone bubbles with a diameter of several millimeters.

[0032] Because ozone bubbles are difficult to dissolve in plating solutions, nanobubbles can be introduced into the plating solution at high pressure. These nanobubbles can remain in the plating solution for extended periods of time. Furthermore, nanobubbles have a much larger specific surface area than the normal ozone bubbles (several millimeters in diameter) emitted from diffusers, allowing for the oxidative decomposition of organic compounds with only a small amount of ozone bubbles. For example, when 2 L of normal ozone bubbles are supplied per minute through a diffuser, the average diameter of the normal ozone bubbles is 2 mm. On the other hand, if the average diameter of nanobubbles is 100 nm, the specific surface area of ​​the nanobubbles is 20,000 times larger than that of normal ozone bubbles (average diameter: 2 mm). This clearly demonstrates the significant difference in oxidative decomposition capacity between these two types of bubbles. Therefore, when introducing ozone bubbles into a plating solution, it is preferable to choose between normal ozone bubbles (several millimeters in diameter) or nanobubbles depending on the amount of residual organic compounds to be removed from the plating solution.

[0033] Ozone concentration: In the method for removing organic agents contained in a plating solution according to the present application, ozone bubbles are introduced at an ozone concentration appropriate for the amount of organic agents to be oxidatively decomposed and removed in the solution. Therefore, there are no particular limitations on the ozone concentration. For example, in the case of ozone normal bubbles using a diffuser plate or the like, an ozone concentration of 50 ppm or higher is preferable. In such cases, an ozone concentration below 50 ppm is undesirable because it does not adequately decompose the organic agents. While there is no particular upper limit, it is preferable to use an ozone concentration of up to approximately 300 ppm depending on the amount of organic agents remaining in the plating solution. In such cases, an ozone concentration above 300 ppm is undesirable because it may corrode the electroplating electrodes and increase the processing time required to remove ozone normal bubbles from the plating solution when regenerating the plating solution, thereby increasing production costs.

[0034] However, when using ozone nanobubbles, it is preferable to introduce them into the used plating solution so that the ozone concentration is 2 ppm to 40 ppm. In this case, an ozone concentration of less than 2 ppm is undesirable because it becomes difficult to remove the organic agent remaining in the plating solution even with the specific surface area of ​​the ozone nanobubbles. On the other hand, in this case, an ozone concentration of more than 40 ppm is undesirable because the ozone nanobubbles remain in the plating solution for a long time, which makes it difficult to remove the ozone nanobubbles when regenerating the plating solution.

[0035] Ozone Treatment Time: In the method for removing organic agents from a plating solution according to the present application, the time required for oxidative decomposition can be adjusted appropriately depending on the type and concentration of ozone bubbles introduced into the used plating solution, taking into account the amount of organic agents in the solution to be oxidatively decomposed and removed. For example, when ozone normal bubbles are introduced into the used plating solution at an ozone concentration ranging from 50 ppm to 300 ppm, the used plating solution is preferably contacted with the ozone normal bubbles for 0.5 to 3.5 hours. Contact times of less than 0.5 hours tend to be insufficient to fully oxidize and decompose the organic agents remaining in the used plating solution, which is undesirable. On the other hand, contact times of more than 3.5 hours are undesirable because further improvement in the oxidative decomposition effect of organic agents cannot be expected and the process is costly.

[0036] Furthermore, when ozone nanobubbles are introduced into a used plating solution at an ozone concentration range of 2 ppm to 40 ppm, the used plating solution is preferably contacted with the ozone nanobubbles for 0.5 to 3.5 hours. Contact times of less than 0.5 hours tend to be insufficient to oxidize and decompose organic agents remaining in the used plating solution, which is undesirable. On the other hand, contact times of more than 3.5 hours are undesirable because further improvement in the oxidative decomposition effect of organic agents cannot be expected and the cost increases.

[0037] B. Methods for regenerating plating solution The plating solution regeneration method according to the present application is a method for regenerating an organic-agent-removed plating solution after removal of residual organic agents by the above-described method for removing organic agents contained in the plating solution. The organic-agent-removed plating solution is subjected to ultraviolet irradiation or heat treatment by heating to 80°C to 95°C and leaving for 15 to 30 minutes, thereby completely removing any ozone bubbles remaining in the solution and producing a regenerated plating solution. When the plating process is electrolytic plating, the above-described ultraviolet irradiation or heat treatment of the plating solution removes ozone bubbles from the solution, thereby preventing electrodes from being oxidized and passivated. Even when the plating process is electroless plating, useful components in the plating solution can be prevented from being oxidized and losing their original functions. The ultraviolet lamp used for the ultraviolet irradiation process is not particularly limited, as long as it is an ozone-free lamp that does not generate ozone, and a commonly used wavelength such as 254 nm, 275 nm, or 365 nm may be used. The UV irradiation time for the organic agent removal plating solution can be adjusted appropriately based on the wavelength and irradiation intensity, and the amount of ozone contained in the organic agent removal plating solution after UV irradiation can be determined using an ozone concentration measuring device such as a dissolved ozone concentration meter using absorptiometry. Heat treatment of the organic agent removal plating solution at a heat treatment temperature below 80°C is undesirable because it tends to be ineffective in removing ozone bubbles from the organic agent removal plating solution. Heat treatment at a temperature above 95°C is undesirable because the evaporation rate of the water solvent becomes too fast, making it difficult to regenerate the plating solution even if organic additives are subsequently replenished. Heat treatment of the organic agent removal plating solution for a heating time of less than 15 minutes is undesirable because it tends to be incomplete in removing ozone bubbles. Heat treatment for a heating time of more than 30 minutes is undesirable because the evaporation rate of the water solvent becomes too high, making it difficult to regenerate the plating solution even if organic additives are subsequently replenished.

[0038] In the plating solution regeneration method according to the present application, it is preferable to remove organic compounds that are not decomposed by ozone by an adsorption method. For example, a configuration is adopted in which the plating solution in the plating tank is circulated through a circulation flow path using a pump, and the plating solution flowing through this flow path is subjected to an adsorption treatment, thereby removing the organic compounds that are not decomposed by ozone. Here, the adsorption method can be a conventionally known method, such as using a filter containing activated carbon, zeolite, or the like.

[0039] In the plating solution regeneration method according to the present application, it is preferable to analyze the remaining organic additives in the plating solution after completion of the ultraviolet irradiation treatment or heat treatment, and adjust the amount of organic additives necessary for plating operation. By adjusting the amount of organic additives in this manner, it becomes possible to reliably manage the plating solution. The amount of organic additives remaining in the plating solution can be analyzed by any conventional method, such as the potassium bromide (KBr) tablet method using a Fourier transform infrared spectrophotometer (FT-IR), high performance liquid chromatography (HPLC), or a Hull cell test based on plating appearance.

[0040] Hereinafter, a method for removing an organic agent contained in a plating solution according to the present application and a method for regenerating the plating solution will be described through examples. [Example]

[0041] In Example 1, the effectiveness of oxidative decomposition and removal of organic agents contained in used plating solution was confirmed using an apparatus 1 configured as shown in FIG. 1 . The apparatus 1 used in Example 1 includes an oxygen generator 2, an ozone generator 3, and an air diffuser 5, which are connected via piping 6. The air diffuser 5 is disposed in a plating tank 4 storing used plating solution W, and supplies ozone, which is used for oxidative decomposition of organic agents, to the used plating solution W by bubbling. In Example 1, normal ozone bubbles with an average particle size of 2 mm were supplied to 1 L of used plating solution W adjusted to 25°C or below at a concentration of 100 ppm to 150 ppm. The amount of organic agents (organic additives and their decomposition products) contained in the used plating solution W was measured using cyclic voltammetric stripping (CVS) analysis and a potassium bromide (KBr) tablet method using a Fourier transform infrared spectrophotometer (FT-IR). In addition, to confirm the amount of organic substances decomposed and removed from the used plating solution W after the introduction of ozone normal bubbles, the potassium bromide (KBr) tablet method in a Fourier transform infrared spectrophotometer (FT-IR) was used.

[0042] The used plating solution W used in this Example 1 was an aqueous solution having the following composition. Copper sulfate: 200g / L Sulfuric acid: 50g / L Chlorine: 50mg / L Organic additive "precipitation inhibitor" (PEG (polyethylene glycol) with an average molecular weight of 3000) and its decomposition products: 60 mg / L Organic additive "precipitation accelerator" (SPS (Bis(3-sulfopropyl)disulfide)) and its decomposition products: 60 mg / L Organic additive "smoothing agent" (JGB (Janus Green B)) and its decomposition products: 60 mg / L

[0043] Under the above conditions, we confirmed the effectiveness of decomposition and removal of organic compounds contained in used plating solutions. Results showed that ozone barely decomposed "PEG and its decomposition products (in this case, "decomposition products" refers to polyethylene glycol, which has been degraded and reduced in molecular weight due to use of the plating solution)," while ozone decomposed "SPS, JGB, and their decomposition products" almost completely oxidized and decomposed within three hours. These results demonstrate that PEG and its decomposition products are not easily decomposed by ozone normal bubbles. However, for these PEGs, the remaining amount of PEG with a normal average molecular weight can be confirmed by cyclic voltammetric stripping (CVS) analysis or Hull cell testing, allowing the plating solution to be adjusted to a normal organic additive concentration by subsequent replenishment. Based on the above, it can be concluded that the method for removing organic compounds contained in plating solutions according to the present application enables the regeneration of plating solutions. [Example]

[0044] In Example 2, an apparatus 10 having the configuration shown in Fig. 2 was used to confirm the effect of decomposing and removing organic agents contained in a used plating solution, as in Example 1. The apparatus 10 used in Example 2 includes an oxygen generator 11, an ozone generator 12, a pump P, and an ozone gas dissolver 13, which are connected via piping 15. The ozone gas dissolver 13 has a structure that converts ozone bubbles generated by the ozone generator 12 into nanobubbles, and supplies the nanobubbled ozone nanobubbles to a used plating solution W stored in a plating tank 14. In Example 2, ozone nanobubbles with an average particle size of 100 nm were supplied at a concentration of 10 ppm to 30 ppm to 20 L of used plating solution W adjusted to 25°C or below. Here, cyclic voltammetric stripping (CVS) analysis and the potassium bromide (KBr) tablet method in a Fourier transform infrared spectrophotometer (FT-IR) were used to measure the amount of organic agents (organic additives and their decomposition products) contained in the used plating solution W. In addition, the potassium bromide (KBr) tablet method in a Fourier transform infrared spectrophotometer (FT-IR) was used to confirm the amount of organic agents decomposed and removed from the used plating solution W after the introduction of ozone nanobubbles.

[0045] The used plating solution W used in this Example 2 was an aqueous solution having the following composition. Copper sulfate: 200g / L Sulfuric acid: 50g / L Chlorine: 50mg / L Organic additive "precipitation inhibitor" (PEG (polyethylene glycol) with an average molecular weight of 3000) and its decomposition products: 60 mg / L Organic additive "precipitation accelerator" (SPS (Bis(3-sulfopropyl)disulfide)) and its decomposition products: 60 mg / L Organic additive "smoothing agent" (JGB (Janus Green B)) and its decomposition products: 60 mg / L

[0046] Under the above conditions, the effectiveness of decomposition and removal of organic compounds contained in used plating solution was confirmed. Similar to Example 1, PEG and its decomposition products (i.e., PEG with an average molecular weight of 3000 and its degraded, lower molecular weight PEG) were hardly decomposed by ozone. However, SPS, JGB, and their decomposition products were almost completely decomposed by oxidation within 3 hours. These results demonstrate that PEGs are difficult to decompose even with ozone nanobubbles. However, even in this case, for the reasons described in Example 1, it can be said that regeneration of the plating solution is possible. Furthermore, these results demonstrate that nanobubbles in ozone further enhance the decomposition and removal of SPS and JGB. [Example]

[0047] In Example 3, the effectiveness of regenerating a plating solution was confirmed using an organic agent-removed plating solution in which organic agents contained in used plating solution W were removed by the method of Example 1. In this Example 3, first, the organic agent-removed plating solution was irradiated with light having a wavelength of 275 nm and an irradiation intensity of 20 mW / cm. 2 The ozone normal bubbles contained in the organic agent removal plating solution were removed by irradiating it with an ultraviolet lamp from above for 15 minutes. Here, the amount of ozone contained in the organic agent removal plating solution after ultraviolet irradiation was confirmed using a dissolved ozone concentration meter that uses absorptiometry.

[0048] Under the above conditions, the effectiveness of UV irradiation in removing ozone bubbles from organic agent-removed plating solution was confirmed, and it was found that normal ozone bubbles introduced into used plating solution W were completely removed from the solution after 15 minutes of UV irradiation. From these results, it can be said that by performing UV irradiation on organic agent-removed plating solution after removing residual organic agents, which is the plating solution regeneration method according to the present application, it is possible to remove normal ozone bubbles remaining in the solution and produce a regenerated plating solution. [Industrial Applicability]

[0049] The method for removing organic agents contained in a plating solution according to the present application allows for the removal of organic agents from a used plating solution using a simpler and more convenient method, and can therefore be widely used as a method for regenerating a plating solution. [Explanation of symbols]

[0050] 1. Device (for ozone normal bubbles) 2. Oxygen generator 3. Ozone Generator 4 Plating tank 5. Air diffuser 6 Piping 10. Device (for ozone nanobubbles) 11 Oxygen generator 12 Ozone Generator 13 Ozone gas dissolver 14 Plating tank 15 Piping P pump W Used plating solution

Claims

1. A method for removing organic agents contained in a used plating solution after a plating operation, comprising: The organic agent is one or more of bis(3-sulfopropyl)disulfide (SPS), Janus Green B (JGB), saccharin, 2-butyne-1,4-diol, sodium lauryl sulfate, 2,5-dimethyl-3-hexyne-2,5-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3-hexyne-2,5-diol, propargyl alcohol, 2,4-hexadiyne-1,6-diol, acetylene, 3,5-dimethyl-1-hexyne-3-ol, 2-methyl-3-butyne-2-ol, 3-methyl-1-pentyne-3-ol, acetylenedicarboxylic acid, and thiourea, and decomposition products thereof; A method for removing organic agents contained in a used plating solution, characterized by introducing ozone bubbles having an average bubble diameter of 20 nm to 500 nm into the used plating solution, and oxidatively decomposing the organic agents using only the ozone, causing them to be separated and removed by vaporization or precipitation.

2. 2. The method for removing organic agents contained in used plating solution according to claim 1, wherein the ozone bubbles are introduced into the used plating solution so that the ozone concentration is 2 ppm to 40 ppm.

3. 3. The method for removing organic agents contained in a used plating solution according to claim 1, wherein the oxidative decomposition is carried out by contacting the used plating solution with ozone bubbles for 0.5 to 3.5 hours.

4. A method for regenerating a plating solution, which is used to regenerate an organic agent-removed plating solution after removing an organic agent by the method for removing an organic agent contained in a used plating solution according to any one of claims 1 to 3, The plating solution is then subjected to ultraviolet irradiation or heat treatment in which the organic agent-removed plating solution is heated to 80°C to 95°C and left for 15 to 30 minutes, thereby removing ozone bubbles remaining in the solution and producing a regenerated plating solution.

5. 5. The method for regenerating a plating solution according to claim 4, wherein the remaining amount of the organic additive is analyzed after the ultraviolet irradiation treatment or the heat treatment is completed, and the amount of the organic additive necessary for the plating operation is adjusted.

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