A plating solution for direct plating of a circuit board and a method for preparing and using the same

Abstract

The application provides a kind of line plate direct electroplating processing liquor and its preparation method and application, and belongs to line plate processing technical field.The electroplating processing liquor includes the following mass percentage components:1.5%-10% dispersing agent, 0.05%-1% water quality stabilizer, 1.5%-10% carbon material, 0.5%-2.5% pH regulator;The carbon material is carbon nanotube or a mixture of carbon nanotube and carbon black with any mass ratio;The pH regulator is used to adjust the pH of the liquor to 8-10.When the electroplating processing liquor is used for the hole conduction treatment of line plate, it is not necessary to carry out twice black hole or twice black shadow, which simplifies the preparation process of line plate and reduces the production cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of circuit board processing, and particularly relates to a direct electroplating treatment liquid for circuit boards, a preparation method and application thereof. BACKGROUND

[0002] Common through holes (or conductive holes) on a circuit board are through holes, blind holes and buried holes. The copper foil lines between conductive patterns in different layers of the circuit board are electrically connected through the through holes. The hole walls of such holes are deposited with conductive materials to allow current and signals to freely flow between different layers.

[0003] Currently, there are three methods for the hole conduction treatment on the circuit board in the industry: one is chemical copper plating; two is to deposit a layer of conductive carbon layer on the hole wall; three is to form a layer of conductive polymer on the hole wall through polymerization. Among them, the complexing agent and chelating agent used in the first method of chemical copper plating need long-term monitoring and management; the reducing agent formaldehyde is highly toxic; the copper plating layer is prone to porosity; the treatment solution has short service life; the waste liquid of colloidal palladium is difficult to treat; the treatment solution is expensive; the water consumption is large, and the wastewater treatment is difficult. The second method is a direct black hole process using carbon black or graphite as a conductive medium. The process flow mainly includes cleaning and hole, one-time black hole, hole, two-time black hole, micro-etching, oxidation resistance and discharge steps. The cost of this method is only half of that of the traditional chemical copper plating process, and the processing time is shortened from tens of minutes to a few minutes, greatly improving the production efficiency, and the discharge of waste liquid and waste gas in the operation process is greatly reduced. However, the black hole liquid used in this method uses water as a dispersion solvent. Due to the poor hydrophilicity of carbon black or graphite, the suspension is unstable and prone to aggregation, which affects the performance of the black hole liquid. Even if a dispersing agent is added, the aggregation phenomenon still occurs during storage, which cannot fundamentally solve the stability problem of the black hole liquid. On the other hand, if only one black hole is made in this method, the proportion of the area not covered by the carbon film increases, the hole breaking rate also increases, and the thickness of the carbon film is less than that of two carbon films, which also leads to relatively low conductivity, thereby affecting the plating depth. Especially in the graphite shadow process, the graphite powder is difficult to disperse uniformly and stably in water like carbon black. In actual use, the graphite sludge deposited at the bottom of the cylinder needs to be cleaned regularly (1-2 months). In addition, the graphite treated in the graphite shadow process needs to be developed (or fixed), which requires frequent replacement of the bath. Due to this step, the production equipment cost and actual production cost are higher than those of the black hole process using carbon black as the conductive medium. The third method uses high-molecular conductive polymer (conjugated polymer, such as polyaniline, polypyrrole, polythiophene, polyphenylene acetylene, polyphenylene sulfide, etc.) to realize hole metallization. The reaction conditions are harsh; the cost of some polymer monomers is high, which increases the cost; and most of the direct plating techniques of conductive polymers are directly plated on the insulating substrate covered with copper foil on one end. Without covering copper foil, no matter how high the voltage is, metal deposition cannot be carried out. SUMMARY

[0004] Based on the above technical problems, the present application provides a kind of direct plating treatment liquor of circuit board. When the liquor is used for the hole conduction treatment of circuit board, it does not need to be blackened twice or blackened twice, which simplifies the preparation process of circuit board.

[0005] In order to achieve the above purpose, the present application specifically adopts the following technical solutions:

[0006] The direct electroplating processing solution for a circuit board comprises the following components in percentage by mass: 1.5-10% dispersant, 0.05-1% water quality stabilizer, 1.5-10% carbon material, and 0.5-2.5% pH regulator; the carbon material is carbon nanotube or a mixture of carbon nanotube and carbon black in any mass ratio; the pH regulator is used to adjust the pH of the solution to 8-10.

[0007] In a preferred embodiment, the mass ratio of the carbon black to the carbon nanotube is (14:1)-(4:1).

[0008] In a further preferred embodiment, the mass ratio of the carbon black to the carbon nanotube is 8:1.

[0009] In a preferred embodiment, the dispersant is polyacrylic substance or / and polyurethane substance.

[0010] In a preferred embodiment, the dispersant is used in an amount of 1.5-3.0%.

[0011] In a preferred embodiment, the water quality stabilizer is at least one of citrate, polyphosphate, sodium salt of EDTA, and potassium salt of EDTA.

[0012] In a preferred embodiment, the water quality stabilizer is used in an amount of 0.1-0.5%.

[0013] In a preferred embodiment, the pH regulator is at least one of organic amine, inorganic base, and inorganic salt with alkaline aqueous solution.

[0014] In a preferred embodiment, the carbon material is used in an amount of 1.5-2.5%.

[0015] In a preferred embodiment, the carbon nanotube has an axial length of ≤2 microns and a tube diameter of ≤20 nanometers.

[0016] In a preferred embodiment, the carbon black has a particle size of ≤40 nm.

[0017] The application further provides a preparation method of the direct electroplating processing solution for a circuit board as described in any of the above embodiments, comprising the following steps: adding the dispersant, water quality stabilizer and pH regulator into water, mixing uniformly to obtain solution A; placing the solution A in a cylindrical storage tank, adding the carbon material into the cylindrical storage tank, mixing uniformly, performing ultrasonic treatment, and then performing homogenization treatment.

[0018] In a preferred embodiment, the ultrasonic treatment has a power density of ≥0.5 W / cm 2 , a treatment time of ≥4 hours, and a temperature of the reaction system of ≤35°C during the treatment.

[0019] In a preferred embodiment, the ratio of the diameter to the height of the cylindrical tank is (1-2):1.

[0020] In a preferred embodiment, the rotation speed during the homogenization process is greater than or equal to 3500 rpm, and the time is 2-3 hours.

[0021] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0022] (1) The particle size of the electroplating treatment solution in the present application is controlled to be 100-300 nm, and the solid content is 3wt%-20wt%. After the through holes of the circuit board are treated by the electroplating treatment solution provided by the present application, the conductive performance of the carbon film deposited on the hole wall is better than that of the black hole (according to the test method in the present application, the resistance of the black hole solution on the market ranges from 28-45MΩ, while the resistance of the solution in the present application ranges from 8-14MΩ).

[0023] (2) When the through holes of the circuit board are treated by the electroplating treatment solution of the present application, only one treatment is needed for the holes, without the need for two times of black hole or black shadow, which simplifies the preparation process of the circuit board and reduces the production cost of the circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure is a measurement schematic diagram for measuring the resistance of the electroplating treatment solution coating in the present application.

[0025] Figure 2 The figure is a DTV sheet before being treated by the electroplating treatment solution provided by the present application.

[0026] Figure 3 The figure is a DTV sheet after being treated by the electroplating treatment solution.

[0027] Figure 4 The figure is an electroplating test device used in the present application. DETAILED DESCRIPTION

[0028] The following content describes the technical scheme of the present application in combination with the embodiments, so that those skilled in the art can fully understand the present application. Obviously, the described embodiments are only a part of the preferred embodiments of the present application, but not all the embodiments. Any equivalent transformation or replacement of the following embodiments made by those skilled in the art without creative labor is within the protection scope of the present application.

[0029] The embodiment of the present application provides a preparation method of a plating solution for direct plating of a circuit board, comprising the following steps: adding a dispersant, a water quality stabilizer and a pH regulator into water, mixing uniformly to obtain a solution A; placing the solution A into a cylindrical storage tank, adding carbon material into the cylindrical storage tank, mixing uniformly, performing ultrasonic treatment, and then performing homogenization treatment. The mass percentage of the dispersant in the total mass of the solution A and the carbon material is 1.5%-10%, the mass percentage of the water quality stabilizer in the total mass of the solution A and the carbon material is 0.05%-1%, the mass percentage of the carbon material in the total mass of the solution A and the carbon material is 1.5%-10%, and the mass percentage of the pH regulator in the total mass of the solution A and the carbon material is 0.5%-2.5%. The pH regulator is used to adjust the pH of the solution to 8-10. The carbon material is carbon nanotubes or a mixture of carbon nanotubes and carbon black with an arbitrary mass ratio.

[0030] For example, the mass percentage of the dispersant in the total mass of the solution A and the carbon material is 1.5%, 1.6%, 1.7%, 1.8%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%,..., 9.8% or 10.0%.

[0031] In a preferred embodiment, the dispersant is a polyacrylic substance or / and a polyurethane substance.

[0032] In a preferred embodiment, the water quality stabilizer is at least one of a citrate, a polyphosphate, an EDTA sodium salt and an EDTA potassium salt.

[0033] For example, the water quality stabilizer is at least one of sodium citrate, sodium tripolyphosphate, disodium EDTA and dipotassium EDTA.

[0034] For example, the mass percentage of the water quality stabilizer in the total mass of the solution A and the carbon material is 0.05%, 0.06%, 0.08%, 0.1%, 0.12%, 0.15%, 0.2%, 0.25%, 0.3%, 0.45%, 0.6%, 0.8%, 0.85%, 0.9% or 1%.

[0035] In a preferred embodiment, the pH regulator is at least one of an organic amine, an inorganic base and an inorganic salt with alkaline aqueous solution.

[0036] For example, the organic amine includes alcohol amine (such as ethanol amine and triethanol amine), aliphatic amine (such as cyclopropyl amine and ethylenediamine), amide (such as formamide and acrylamide), alicyclic amine (such as cyclohexyl amine), aromatic amine (such as aniline and benzidine) and other amine compounds (such as polyethylene imine and hydroxyl amine).

[0037] As an example, the inorganic base is an alkali metal hydroxide (e.g., sodium hydroxide, potassium hydroxide) or aqueous ammonia.

[0038] As an example, the inorganic salt that renders the aqueous solution basic includes at least one of an alkali metal carbonate (e.g., sodium carbonate, potassium carbonate), an alkali metal bicarbonate (e.g., sodium bicarbonate), an alkali metal phosphate (e.g., sodium phosphate).

[0039] As an example, the pH adjusting agent adjusts the pH of the stock solution to 8.0, 8.1, 8.2, 8.3, 8.5, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, or 10.0.

[0040] As an example, the mass of the pH adjusting agent is 0.5%, 0.6%, 0.7%, 0.8%, 1.0%, 1.2%, 1.5%, 1.6%, 1.8%, 2.0%, 2.1%, or 2.5% of the total mass of Solution A and the carbon material.

[0041] In preferred embodiments, the carbon nanotubes have an axial length of ≤ 2 microns and a tube diameter of ≤ 20 nanometers.

[0042] As an example, the mass of the carbon material is 1.5%, 1.6%, 1.8%, 1.9%, 2.0%, 2.2%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, or 10% of the total mass of Solution A and the carbon material.

[0043] As an example, the carbon nanotubes are single-walled carbon nanotubes or multi-walled carbon nanotubes, have an axial length of 0.5-0.7 μm, 1-1.5 μm, or 1.5-2 μm, and a tube diameter of 1-2 nm, 10-20 nm, or 20-40 nm.

[0044] In preferred embodiments, the ultrasonic treatment has a power density of ≥ 0.5 W / cm 2 , a treatment time of ≥ 4 hours, and a temperature of the reaction system of ≤ 35 °C during the treatment.

[0045] As an example, the ultrasonic treatment has a power density of 0.5 W / cm 2 , 0.7 W / cm 2 , or 1.0 W / cm 2 , a treatment time of 4 h, 5 h, or 6 h.

[0046] In preferred embodiments, the ratio of the diameter to the height of the cylindrical tank is (1-2): 1.

[0047] As an example, the ratio of the diameter to the height of the cylindrical tank is 1:1, 1.5:1 or 2:1.

[0048] In a preferred embodiment, the homogenization treatment is performed using a sand mill or a homogenizer at a rotation speed of > 3500 rpm for 2-3 hours.

[0049] As an example, the speed of the homogenization treatment is 3500 rpm, 3600 rpm, 3800 rpm, 4000 rpm or 4500 rpm; the homogenization treatment time is 2 hours, 2.5 hours or 3 hours.

[0050] The 1# commercially available dispersant used in the following specific examples is WinSperse 2050 from WinSperse New Material (Shandong) Co., Ltd. The 2# commercially available dispersant is WinSperse 4950 from WinSperse New Material (Shandong) Co., Ltd. The 3# commercially available dispersant is DISPERBYK 184 dispersant produced by BYK Chemie, Germany. The 4# commercially available polyurethane dispersant is Solsperse WV-400 produced by Lubrizol. The 5# commercially available dispersant is DISPERBYK 2055 dispersant produced by BYK Chemie, Germany.

[0051] Example 1

[0052] A preparation method of a direct electroplating treatment solution for a circuit board is as follows: 5 grams of ethanolamine (pH regulator), 15 grams of 1# commercially available dispersant, and 1 gram of sodium citrate (water quality stabilizer) are dissolved in 964 grams of deionized water by stirring to obtain solution A. The pH of solution A is 10.9. Solution A is placed in a cylindrical tank, 14 grams of commercially available conductive carbon black and 1 gram of carbon nanotube are added to solution A, and then an ultrasonic disperser (ultrasonic power density is 1.0 W / cm 2 ) is used for treatment for 4 hours, and the temperature during the treatment process is ensured to be no more than 35°C. Finally, a 0.5 liter sand mill is used for treatment for 2 hours to obtain an electroplating treatment solution with a pH of 9.3-9.5, which is ready for use. The carbon nanotube is a single-walled carbon nanotube with an axial length of 500-700 nm and a tube diameter of 1-2 nm. The ratio of the diameter to the height of the cylindrical tank is 1:1.

[0053] Example 2

[0054] A preparation method of a direct electroplating treatment solution for a circuit board is as follows: 10 grams of triethanolamine (pH regulator), 18 grams of 2# commercially available dispersant, and 5 grams of sodium triphosphate (water quality stabilizer) are dissolved in 949 grams of deionized water by stirring to obtain solution A. The pH of solution A is 10.2. Solution A is placed in a cylindrical tank, 16 grams of commercially available conductive carbon black and 2 grams of carbon nanotube are added to solution A, and then an ultrasonic disperser (ultrasonic power density is 0.7 W / cm 2) for 4 hours, ensuring that the temperature does not exceed 35°C during the treatment. Finally, the solution is treated with a 0.5 liter sand mill for 3 hours to obtain a plating treatment solution with a pH of 9.4-9.7 for standby use. The carbon nanotubes are multi-walled carbon nanotubes with an axial length of 1-1.5 μm and a tube diameter of 10-20 nm. The ratio of the diameter to the height of the cylindrical storage tank is 1.5:1.

[0055] Example 3

[0056] A plating treatment solution for a circuit board is prepared as follows: 15 grams of cyclopropylamine (pH adjuster), 20 grams of commercially available dispersant No. 3, and 5 grams of sodium citrate (water quality stabilizer) are dissolved in 940 grams of deionized water with stirring to obtain solution A. The pH of solution A is 10.7. Solution A is placed in a cylindrical storage tank, and 16 grams of commercially available conductive carbon black and 4 grams of carbon nanotubes are added to solution A, which is then dispersed using an ultrasonic disperser (ultrasonic power density of 0.6 W / cm 2 ) for 4.5 hours, ensuring that the temperature does not exceed 35°C during the treatment. Finally, the solution is treated with a 0.5 liter sand mill for 2 hours to obtain a plating treatment solution with a pH of 9.4-9.8 for standby use. The carbon nanotubes are multi-walled carbon nanotubes with an axial length of 1.5-2 μm and a tube diameter of 20-40 nm. The ratio of the diameter to the height of the cylindrical storage tank is 2:1.

[0057] Example 4

[0058] A plating treatment solution for a circuit board is prepared as follows: 25 grams of sodium carbonate (pH adjuster), 30 grams of commercially available polyurethane dispersant No. 4, and 5 grams of disodium EDTA (water quality stabilizer) are dissolved in 915 grams of deionized water with stirring to obtain solution A. The pH of solution A is 10.9. Solution A is placed in a cylindrical storage tank, and 25 grams of commercially available carbon nanotubes are added to solution A, which is then dispersed using an ultrasonic disperser (ultrasonic power density of 0.5 W / cm 2 ) for 5 hours, ensuring that the temperature does not exceed 35°C during the treatment. Finally, the solution is treated with a 0.5 liter sand mill for 3 hours to obtain a plating treatment solution with a pH of 9.3-9.7 for standby use. The carbon nanotubes are multi-walled carbon nanotubes with an axial length of 1.5-2 μm and a tube diameter of 20-40 nm. The ratio of the diameter to the height of the cylindrical storage tank is 1.2:1.

[0059] Comparative Example 1

[0060] A preparation method of a direct plating treatment solution for a circuit board is as follows: 5 grams of ethanolamine (pH regulator), 15 grams of commercially available dispersant No. 1, and 1 gram of sodium citrate (water stabilizer) are dissolved in 964 grams of deionized water by stirring to obtain solution A. The pH of solution A is 10.9. Solution A is placed in a cylindrical storage tank, 15 grams of commercially available conductive carbon black is added to solution A, and then a 0.5-liter sand mill is used for treatment for 2 hours to obtain a plating treatment solution with a pH of 9.3-9.5, which is ready for use. The carbon nanotubes are single-walled carbon nanotubes with an axial length of 500-700 nm and a tube diameter of 1-2 nm. The ratio of the diameter to the height of the cylindrical storage tank is 1:1. That is, the difference between the present comparative example and Example 1 is that the same mass of conductive carbon black is used to replace the conductive carbon black and carbon nanotubes in Example 1, and ultrasonic treatment is not needed.

[0061] Comparative Example 2

[0062] A preparation method of a direct plating treatment solution for a circuit board is as follows: 10 grams of triethanolamine (pH regulator), 18 grams of dispersant NNO (methylene bis-naphthalene sulfonic acid sodium salt), and 5 grams of sodium triphosphate (water stabilizer) are dissolved in 949 grams of deionized water by stirring to obtain solution A. The pH of solution A is 11.1. Solution A is placed in a cylindrical storage tank, 16 grams of commercially available conductive carbon black and 2 grams of carbon nanotubes are added to solution A, and then an ultrasonic disperser (ultrasonic power density is 0.5 W / cm 2 ) is used for treatment for 4 hours to ensure that the temperature during the treatment process does not exceed 35℃. Finally, a 0.5-liter sand mill is used for treatment for 3 hours to obtain a plating treatment solution with a pH of 9.3-9.6, which is ready for use. The carbon nanotubes are multi-walled carbon nanotubes with an axial length of 1-1.5 μm and a tube diameter of 10-20 nm. The ratio of the diameter to the height of the cylindrical storage tank is 1.5:1. That is, the difference between the present comparative example and Example 2 is that the dispersant is replaced by NNO.

[0063] Comparative Example 3

[0064] A preparation method of a direct plating treatment solution for a circuit board is as follows: 15 grams of cyclopropylamine (pH regulator) and 20 grams of commercially available dispersant No. 5 are dissolved in 945 grams of deionized water by stirring to obtain solution A. The pH of solution A is 10.8. Commercially available conductive carbon black 16 grams and carbon nanotubes 4 grams are added to solution A, and then an ultrasonic disperser (ultrasonic power density is 0.5 W / cm 2) and the temperature during the treatment process is ensured to be no more than 35°C. Finally, the solution is treated by a 0.5 liter sand mill for 2 hours to obtain a plating treatment solution with a pH of 9.4-9.8 for standby use. In the present example, the carbon nanotubes are multi-walled carbon nanotubes with an axial length of 1.5-2 μm and a tube diameter of 20-40 nm. The ratio of the diameter to the height of the cylindrical storage tank is 2:1. That is, the difference between the present example and Example 3 is that the dispersant is BYK DISPERBYK 2055 and no water stabilizer is used.

[0065] Comparative Example 4

[0066] A plating treatment solution for a circuit board was prepared as follows: 35 g of potassium hydroxide (pH adjuster), 30 g of commercially available polyurethane dispersant (4#), 5 g of disodium EDTA (water stabilizer) were dissolved in 905 g of deionized water to obtain solution A. The pH of solution A was 13.2. Solution A was placed in a cylindrical storage tank, 25 g of commercially available carbon nanotubes were added to solution A, and then an ultrasonic dispersing machine was used for treatment for 5 hours, with the temperature during the treatment process being ensured to be no more than 35°C. Finally, the solution was treated by a 0.5 liter sand mill for 3 hours to obtain a plating treatment solution with a pH of 11.5-12.0 for standby use. In the present example, the carbon nanotubes are multi-walled carbon nanotubes with an axial length of 1.5-2 μm and a tube diameter of 10-20 nm. The ratio of the diameter to the height of the cylindrical storage tank is 1.2:1. That is, the difference between the present example and Example 4 is that the pH adjuster is replaced by potassium hydroxide and the amount is increased.

[0067] Effect verification

[0068] A total of 200 ml of each of the six samples of the plating treatment solutions prepared in Examples 2-4 and Comparative Examples 2-4 was diluted to 1000 ml for testing. The plating treatment solution prepared in Example 1 and Comparative Example 1 was not diluted and was directly used for testing. The test items included pH value, solid content, particle size, fixed length-width area coating resistance, and DTV sheet test. The number of tests was 3, i.e., initial test, test after storage for 1 month, and test after storage for 3 months. The test results are shown in Table 1.

[0069] pH value test method: pH meter (brand: Leici).

[0070] Solid content test method: moisture meter.

[0071] Particle size measurement method: laser particle size analyzer (Malvern).

[0072] Fixed length-width area coating resistance measurement method: 10-15 ml of sample was loaded into an empty pen tube and a 200 mm long and 5 mm wide rectangle was drawn on A4 paper (as shown in the figure below) to obtain a coating layer with a fixed length-width area. The resistance of the coating layer was measured by a multimeter. Figure 1As shown), use a multimeter to measure the resistance between the two endpoints along the long side. The main components of commercially available black hole solution are as follows: 1wt%~2wt% (e.g., 1.5wt%) of high-pigment carbon black, 1wt%~2wt% (e.g., 1.5wt%) of polyacrylic acid dispersant (e.g., BYK Chemical's DISPERBYK2055), and pH 9.3~10.1 (e.g., pH 9.4~9.6).

[0073] DTV film testing method:

[0074] like Figures 2-3 As shown, the DTV film was processed according to the following process: A 5wt% cleaning agent (the main components of the cleaning agent are: 3wt%-6wt% quaternary ammonium cationic surfactant, 3wt%-5wt% nonionic surfactant, pH 10-11; for example, the main components of the cleaning agent are: 5wt% quaternary ammonium cationic surfactant PN-321 provided by Zhengzhou Yihe Environmental Protection Technology Co., Ltd., 4wt% fatty alcohol polyoxyethylene ether AEO-7, pH 10.5) was used to clean the entire hole at 50-55℃, followed by rinsing with pure water. At 30-35℃, the film was treated with the electroplating solution prepared in the examples or comparative examples, and then dried at 60-80℃. After drying, micro-etching was performed using a 2wt%-3wt% sulfuric acid and a 3wt%-5wt% sodium persulfate solution. Then, the film was rinsed with tap water and dried at 60-80℃. The treated DTV film was placed in a Hull tank for electroplating, and the number of vias in the high-current and low-current regions was observed. The electroplating conditions are: current of 1A, electroplating time of 10 minutes, and temperature of 23~30℃.

[0075] Table 1. Test Results of DTV Films

[0076]

[0077] The experimental results in the table show that during the three-month follow-up experiment, the test results of the prepared solutions in the examples did not change significantly, and the system was relatively stable. Among them, Example 2 (carbon black to carbon nanotube mass ratio of 8:1) was the most stable. The test results of the comparative examples after one month did not meet the usage requirements (number of vias ≥ 5 in the high current region and number of vias ≥ 4 in the low current region).

[0078] The embodiments described above are merely preferred embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by anyone skilled in the art. Any simple equivalent changes and modifications made based on the scope of protection of this application and the content of the specification should be included within the scope of protection of this application.

Claims

1. A solution for direct electroplating of circuit boards, characterized in that, By weight percentage, it comprises the following components: 1.5%~10% dispersant, 0.05%~1% water quality stabilizer, 1.5%~10% carbon material, and 0.5%~2.5% [other components]. pH adjuster; when the carbon material is carbon nanotubes, the axial length of the carbon nanotubes is ≤2 micrometers and the diameter is ≤20 nanometers; when the carbon material is a mixture of carbon nanotubes and carbon black in any mass ratio, the axial length of the carbon nanotubes is ≤2 micrometers and the diameter is ≤20 nanometers, and the particle size of the carbon black is ≤40nm; the pH adjuster is used to adjust the pH of the solution to 8~10; the dispersant is a polyacrylic acid substance or / and a polyurethane substance; the water quality stabilizer is at least one of citrate, polyphosphate, sodium EDTA, and potassium EDTA; the preparation method of the solution includes the following steps: adding the dispersant, water quality stabilizer and pH adjuster to water, mixing evenly to obtain solution A; placing solution A in a cylindrical storage tank, adding the carbon material to the cylindrical storage tank, mixing evenly, and performing ultrasonic treatment, during which the temperature of the reaction system is ≤35℃; and then performing homogenization treatment.

2. The circuit board direct electroplating treatment solution according to claim 1, characterized in that, The pH adjuster is at least one of organic amines, inorganic bases, and inorganic salts whose aqueous solutions are alkaline.

3. The circuit board direct electroplating treatment solution according to claim 1, characterized in that, The mass ratio of carbon black to carbon nanotubes is (14:1) to (4:1).

4. The circuit board direct electroplating treatment solution according to claim 1, characterized in that, The amount of the dispersant is 1.5% to 3.0%; or / and the amount of the carbon material is 1.5% to 2.5%.

5. The method for preparing the direct electroplating treatment solution for circuit boards according to any one of claims 1 to 4, characterized in that, Includes the following steps: The dispersant, water quality stabilizer, and pH adjuster are added to water and mixed evenly to obtain solution A. Solution A is placed in a cylindrical storage tank, and the carbon material is added to the cylindrical storage tank and mixed evenly. The mixture is then subjected to ultrasonic treatment, during which the temperature of the reaction system is ≤35℃. Then, homogenization treatment is performed.

6. The preparation method according to claim 5, characterized in that, The power density of the ultrasonic treatment is ≥0.5W / cm². 2 Processing time is ≥4 hours.

7. The preparation method according to claim 5, characterized in that, The ratio of the diameter to the height of the cylindrical storage tank is (1~2):

1.

8. The application of the direct electroplating treatment solution for circuit boards according to any one of claims 1 to 4 in the preparation of circuit boards.

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