Copper electroplating liquid recycling method and equipment group thereof

Abstract

The invention relates to a copper electroplating liquid recycling method and an equipment group thereof. The using method comprises the following steps: preparing an oxidizing agent, cracking and adsorbing; in the adsorption process, when the adsorption capacity is saturated, the resin is regenerated and reused; and when the TOC of the electroplating solution is reduced to the qualified standard, stopping circulation, analyzing the content of copper sulfate and sulfuric acid in the electroplating solution, adjusting the content to be within the process range, and pumping back to the aqueduct for reuse. According to the method, the oxidizing agent is excited by utilizing the capability of ultraviolet light, so that organic matters in the high-TOC plating solution are quickly cracked under the action of the oxidizing agent and the ultraviolet light, and then the cracked organic matters are adsorbed by utilizing special resin. The process is simple to operate, high in treatment efficiency and capable of effectively saving resources and greatly reducing the production cost of enterprises.

Description

Technical Field

[0001] The invention relates to the technical field of electroplating waste liquid treatment, and in particular to a method for recycling copper electroplating liquid and an equipment group thereof. Background Art

[0002] At present, with the development of electronic technology, the requirements for circuit boards are getting higher and higher, the line width and line spacing of the circuits are getting smaller and smaller, and the number of layers is increasing. In order to ensure the functional requirements, especially the ductility of the plated copper, the plating solution generally needs to be carbon treated when the TOC of the electroplating solution reaches more than 4000ppm. Traditional carbon treatment uses hydrogen peroxide decomposition (high temperature 70-80 degrees, while cracking excess hydrogen peroxide) plus carbon adsorption, which occupies space, takes a long time, produces a large amount of sewage and hazardous waste (carbon powder, etc.), and the plating tank is difficult to clean, and the treatment effect is poor (TOC can only drop by about 10-20%). Therefore, for high-precision circuit boards, in order to ensure the functional requirements of the circuit boards, the only way is to directly replace the new solution. However, the direct discharge of the old plating solution will cause environmental pollution and increase the amount of wastewater treatment, while wasting a lot of manpower, material and financial resources, and greatly increasing the production cost of the enterprise. Summary of the invention

[0003] In view of the shortcomings of the prior art, the first object of the present invention is to provide a method for recycling copper electroplating solution. Through this method, the high TOC plating solution can be regenerated and recycled, solving the technical problem of waste of resources caused by directly replacing the existing circuit board factory plating solution with a new one after the plating solution expires or the TOC exceeds the process requirements.

[0004] The second object of the present invention is to provide an equipment group for recycling copper electroplating solution, through which the above-mentioned method for recycling the electroplating solution can be implemented.

[0005] The technical solution adopted by the first object of the present invention is: a method for recycling copper electroplating solution, comprising the following steps:

[0006] S1. Preparation of oxidizing agent: dilute the cleavage agent with water to the required concentration;

[0007] S2, cracking: the high TOC plating solution in the aqueduct is pumped to the mixing tank, the oxidizing agent is pumped into the pipeline through a metering pump to mix with the high TOC plating solution flowing out of the mixing tank, and then UV cracking is performed by a UV generator;

[0008] S3, adsorption: the cracked electroplating solution is cyclically adsorbed by activated carbon and resin in turn; during the adsorption process, when the adsorption amount is saturated, the resin is regenerated and reused;

[0009] S4. When the TOC of the electroplating solution drops to the qualified standard, stop the circulation, analyze the copper sulfate and sulfuric acid content of the electroplating solution and adjust them to the process range, and then pump them back to the aqueduct for reuse.

[0010] Preferably, the cleavage agent is a substance containing a peroxide bond (-OO-), and the oxidation state of the oxygen atom in the peroxide bond is -1, so it can exhibit extremely strong oxidizing properties; in an acidic environment, the free radicals it produces attack the unsaturated bonds of organic matter, thereby completing a series of oxidation reactions to break the double bonds of the organic matter.

[0011] Preferably, in step S1, the dilution ratio of the lysing agent to water is 1:25 kg / L.

[0012] Preferably, in step S1, the ratio of the amount of the cleavage agent added to the high TOC electroplating solution is 1:10 kg / m 3 .

[0013] Preferably, the resin is an adsorption resin that can adsorb organic impurities such as COD, TOC, dissolved oil, etc. from a liquid, and its functional group is an adsorption group, and its total exchange capacity is ≥100g / l.

[0014] The technical solution adopted by the second object of the present invention is: an equipment group for circulating copper electroplating solution, including a pure water module and a mixing module, an adsorption module and a filtration module connected in sequence through pipelines; wherein,

[0015] The preparation module includes a reagent box and a plurality of copper sulfate preparation tanks arranged in parallel and connected to the plating tank, the copper sulfate preparation tank is connected to the adsorption module through a circulation pipeline 1, the reagent box is arranged between the copper sulfate preparation tank and the adsorption module, and the circulation pipeline 1 is provided with a UV generator between the reagent box and the adsorption module;

[0016] The adsorption module comprises an activated carbon filter tank and a plurality of parallel resin adsorption tanks connected in sequence through a circulation pipeline 2, and the resin adsorption tank is connected to a regeneration module for regenerating saturated resin;

[0017] The filtering module is connected to the copper sulfate preparation tank and the plating tank through the circulation pipeline three and the outflow pipeline respectively;

[0018] The copper sulfate preparation tank, the reagent box and the regeneration module are all connected to the pure water module.

[0019] Preferably, a metering pump is provided on the connecting pipeline between the medicine box and the circulation pipeline 1.

[0020] Preferably, the regeneration module comprises a regeneration water tank and a regeneration pump, and the water in the regeneration water tank enters the resin adsorption tank through the regeneration pump, regenerates the saturated resin and then flows back into the regeneration water tank.

[0021] Preferably, a circulation pump is provided at the connection between the circulation pipeline 1 and the activated carbon filter tank.

[0022] Preferably, the copper sulfate preparation tank, the reagent box and the regenerated water tank are all connected to a sewage pipe.

[0023] Preferably, the filter module is a precision filter, specifically using a 20*18 core 5HP pump.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. The present invention utilizes the ultraviolet light to excite the oxidant, so that the organic matter in the high TOC plating solution is rapidly decomposed under the action of the oxidizing agent and ultraviolet light, and then the decomposed organic matter is adsorbed by a special resin. This process is simple to operate, and only requires the use of a circulating pump to circulate the plating solution, with high processing efficiency, which greatly reduces the production cost of the enterprise.

[0026] 2. The resin adsorption tank of the present invention is connected to the regeneration module, so that the special resin in the tank can also be recycled, which can effectively save resources and further reduce the production cost of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a process flow chart of the present invention.

[0028] Figure 2 It is a schematic diagram of the process of the equipment group of the present invention.

[0029] Figure 3 This is the Haugh slice image before the treatment of Example 1.

[0030] Figure 4 This is the Hastelloy slice image after processing in Example 1.

[0031] The numbers in the figure are as follows:

[0032] 1-agent box, 2-copper sulfate preparation tank, 21-liquid level meter, 22-overflow port, 3-metering pump, 4-UV generator, 5-circulation pump, 6-activated carbon filter tank, 7-resin adsorption tank, 8-regeneration water tank, 9-regeneration pump, 10-precision filter,

[0033] 01-circulation pipeline 1, 02-circulation pipeline 2, 03-circulation pipeline 3, 04-outflow pipeline, 05-pure water main pipeline, 06-pure water branch pipeline, 07-sewage pipe. DETAILED DESCRIPTION

[0034] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with implementation examples and drawings. The present invention can be implemented in the following manner:

[0035] Reference Figure 1-2 , an equipment group for circulating copper electroplating plating solution, including a pure water module and a mixing module, an adsorption module and a filtering module connected in sequence through pipelines. The plating solution can circulate in the mixing module, the adsorption module and the filtering module.

[0036] Specifically, the preparation module includes a reagent box 1 and a plurality of copper sulfate preparation tanks 2 arranged in parallel and connected to the plating tank. The present embodiment is provided with three copper sulfate preparation tanks 2, and one or more of the copper sulfate preparation tanks 2 can be selected for use simultaneously. A liquid level gauge 21 and an overflow port 22 are installed inside the copper sulfate preparation tank 2 to improve safety. The copper sulfate preparation tank 2 is connected to the adsorption module through a circulation pipeline 01, and the reagent box 1 is arranged between the copper sulfate preparation tank 2 and the adsorption module. A metering pump 3 is arranged on the connecting pipeline between the reagent box 1 and the circulation pipeline 01. The reagent box 1 is used to prepare oxidizing agents. The cracking agent is a strong oxidizing substance that has no effect on the electroplating of the plating solution. The metering pump 3 is used to pump it into the circulation pipeline 01 and mix it with the high TOC plating solution. Its main function is to decompose the organic carbon in the high TOC plating solution. The circulation pipeline 01 is provided with a UV generator 4 between the reagent box 1 and the adsorption module; this design mainly utilizes ultraviolet light energy to excite the oxidizing agent, so that the organic matter is rapidly decomposed under the action of the oxidizing agent and ultraviolet light. In addition, the ultraviolet light of the UV generator 4 not only has a photolysis effect, but also has a strong oxidation ability. A circulation pump 5 is provided at the connection between the circulation pipeline 01 and the activated carbon filter tank, and the function of the circulation pump 5 is to circulate the plating solution in the preparation module, the adsorption module and the filtration module.

[0037] In order to fully adsorb the cracked organic matter, the adsorption module includes an activated carbon filter tank 6 and several parallel resin adsorption tanks 7 connected in sequence through a circulation pipeline 202. This embodiment is provided with two resin adsorption tanks 7. The activated carbon in the activated carbon filter tank 6 has a rich microporous structure and a large specific surface area, which can efficiently adsorb organic impurities and some metal ions in the high TOC plating solution, thereby purifying the plating solution, reducing deposition defects, and improving its recycling rate. The resin adsorption tank 7 is connected to a regeneration module for regenerating saturated resin; the regeneration module includes a regeneration water tank 8 and a regeneration pump 9, and the regeneration agent in the regeneration water tank 8 enters the resin adsorption tank 7 through the regeneration pump 9, regenerates the saturated resin and then flows back to the regeneration water tank 8. The design of the regeneration module allows the special resin in the resin adsorption tank 7 to be recycled, which can effectively save resources and further reduce the production cost of the enterprise.

[0038] In order to further improve the purification degree of the plating solution, the filter module is a precision filter 10, which specifically adopts a 20*18 core 5HP pump. The filter module is connected to the copper sulfate preparation tank 2 and the plating tank through the circulation pipeline 3 03 and the outflow pipeline 04 respectively. The circulating plating solution is tested for TOC. If the test fails, the plating solution continues to be recycled; if the test passes, after the copper sulfate and sulfuric acid content in the plating solution is adjusted to the process range, it can be pumped back to the aqueduct for reuse by connecting to a ton barrel or tank truck packaging.

[0039] In order to facilitate preparation and cleaning, the copper sulfate preparation tank 2, the reagent box 1, and the regeneration module are all connected to the pure water module. The pure water module includes a pure water main pipeline 05, a pure water branch pipeline 06, and a plurality of valves arranged on the pipeline. The pure water of the pure water main pipeline 05 enters the copper sulfate preparation tank 2, the reagent box 1, and the regeneration water tank 8 through the pure water branch pipeline 06. The copper sulfate preparation tank 2, the reagent box 1, and the regeneration water tank 8 are all connected to a sewage pipe 07. A transparent tube needs to be installed at all interfaces with valves to ensure that it can be judged whether the valve is closed.

[0040] Example 1

[0041] The method for recycling the copper electroplating solution in this embodiment 1 is based on the above-mentioned equipment group.

[0042] The total volume of the high TOC plating solution to be treated in Example 1 is 20 cubic meters, and the TOC value detected before treatment is 4920 ppm. The treatment method includes the following steps:

[0043] S1. Preparation of oxidizing agent: Add 2 kg of pyrolysis agent into the pyrolysis tank of agent box 1, dilute with pure water to 50 liters, and stir evenly.

[0044] S2, cracking: pump the high TOC plating solution in the aqueduct to the copper sulfate preparation tank 2, turn on the metering pump 3 to adjust the flow rate at 50%, inject the oxidizing agent into the circulation pipeline 01 to mix with the high TOC plating solution flowing out of the copper sulfate preparation tank 2; at the same time, turn on the UV generator 4 to use ultraviolet light energy to excite the oxidizing agent.

[0045] S3, adsorption: open the valves of the activated carbon filter tank 6, the resin adsorption tank 7, and the filter module to the appropriate position, start the circulation pump 5, and circulate for 4 hours. During the adsorption process, when the resin adsorption amount in the resin adsorption tank 7 is saturated, close the circulation pump 5 and the corresponding valves of the deployment module, adsorption module, and filter module, open the regeneration module and the corresponding valve, and regenerate the resin in the resin adsorption tank 7 for reuse.

[0046] S4. After the plating solution circulation is completed, the TOC result is 412ppm, which is qualified and no regeneration circulation is required. At the same time, the content of copper sulfate and sulfuric acid is analyzed and adjusted to the process range. After the plating solution flows out through the outflow pipe 04 of the filter module, it is pumped back to the aqueduct for reuse by connecting to a ton barrel or tank truck packaging.

[0047] Test data:

[0048] 1. The TOC value of the plating solution of Example 1 before treatment is 4920ppm, and the Hastelloy tablets are as follows: Figure 3 As shown; the TOC value after treatment is 412ppm, the Dahashi tablets are as follows Figure 4 As shown. Figure 4 and Figure 3 By comparison, Figure 4 The high and low current areas of the Hastelloy plate are sub-color and matte, indicating that the TOC treatment of the plating solution is qualified.

[0049] 2. Take two samples before and after the plating solution treatment for total organic carbon testing.

[0050] Detection method: "Determination of total organic carbon in water quality - combustion oxidation-non-dispersive infrared absorption method" HJ501-2009;

[0051] Analytical instrument: T0C-2000 total organic carbon analyzer;

[0052] Detection limit: 0.1mg / L

[0053] The test results are shown in Table 1 below:

[0054] Sample name Sample No. Test items Test results Concentration Unit Before copper liquid A treatment SY24042312A01 Total organic carbon <![CDATA[4.44×10 3 ]]> mg / L After treatment with copper liquid A SY24042312A02 Total organic carbon 326 mg / L Before copper liquid B treatment SY24042312A03 Total organic carbon <![CDATA[3.54×10 3 ]]> mg / L After treatment with copper liquid B SY24042312A04 Total organic carbon 224 mg / L

[0055] Table 1

[0056] From the above test data, it can be seen that the method for recycling the copper electroplating solution of the present invention can effectively reduce the TOC of the electroplating solution by more than 90%, which is much higher than the traditional carbon treatment method using hydrogen peroxide decomposition; and the process operation is simple and the treatment efficiency is high, which is suitable for preventive application and promotion.

[0057] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for recycling copper electroplating solution, characterized in that: The following steps are involved: S1. Preparation of oxidizing agent: dilute the cleavage agent with water to the required concentration; S2, cracking: the high TOC plating solution in the aqueduct is pumped to the mixing tank, the oxidizing agent is pumped into the pipeline through the metering pump 3 to mix with the high TOC plating solution flowing out of the mixing tank, and then UV cracking is performed by the UV generator (4); S3, adsorption: the cracked electroplating solution is sequentially adsorbed by activated carbon and resin cycles; During the adsorption process, when the adsorption capacity is saturated, the resin is regenerated and reused; S4. When the TOC of the electroplating solution drops to the qualified standard, stop the circulation, analyze the copper sulfate and sulfuric acid content of the electroplating solution and adjust them to the process range, and then pump them back to the aqueduct for reuse.

2. The method for recycling copper electroplating solution according to claim 1, characterized in that: The cleavage agent is a substance containing a peroxide bond (-OO-), and the oxidation state of the oxygen atom in the peroxide bond is -1.

3. The method for recycling copper electroplating solution according to claim 1, characterized in that: The resin is an adsorption resin, the functional group of which is an adsorption group, and the exchange capacity is ≥100g / l.

4. The method for recycling copper electroplating solution according to claim 1, characterized in that: In the step S1, the dilution ratio of the lysing agent to water is 1:25 kg / L.

5. The method for recycling copper electroplating solution according to claim 1, characterized in that: In step S1, the ratio of the amount of the cleavage agent added to the high TOC electroplating solution is 1:10 kg / m 3 .

6. An equipment group for recycling copper electroplating solution, characterized in that: The invention comprises a pure water module and a mixing module, an adsorption module and a filtration module which are sequentially connected via pipelines; wherein the mixing module comprises a reagent box (1) and a plurality of copper sulfate mixing tanks (2) which are arranged in parallel and connected to a plating tank, the copper sulfate mixing tanks (2) are connected to the adsorption module via a circulation pipeline (01), the reagent box (1) is arranged between the copper sulfate mixing tank (2) and the adsorption module, and the circulation pipeline (01) is provided with a UV generator (4) between the reagent box (1) and the adsorption module; The adsorption module comprises an activated carbon filter tank (6) and a plurality of parallel resin adsorption tanks (7) which are sequentially connected via a circulation pipeline 2 (02); the resin adsorption tank (7) is connected to a regeneration module for regenerating saturated resin; The filtering module is connected to the copper sulfate preparation tank (2) and the plating tank through the circulation pipeline three (03) and the outflow pipeline (04) respectively; The copper sulfate preparation tank (2), the reagent box (1), and the regeneration module are all connected to the pure water module.

7. The equipment group for recycling copper electroplating solution according to claim 6, characterized in that: A metering pump (3) is provided on the connecting pipeline between the medicine box (1) and the circulation pipeline 1 (01).

8. The equipment set for recycling copper electroplating solution according to claim 6, characterized in that: The regeneration module comprises a regeneration water tank (8) and a regeneration pump (9). The water in the regeneration water tank (8) enters the resin adsorption tank (7) through the regeneration pump (9), regenerates the saturated resin and then flows back into the regeneration water tank (8).

9. The equipment set for recycling copper electroplating solution according to claim 6, characterized in that: A circulation pump (5) is provided at the connection between the circulation pipeline 1 (01) and the activated carbon filter tank (6).

10. The equipment group for recycling copper electroplating solution according to claim 6, characterized in that: The copper sulfate preparation tank (2), the reagent box (1) and the regenerated water tank (8) are all connected to a sewage pipe (07).

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