A horizontal chemical copper plating solution and preparation method thereof

Abstract

The present application relates to the technical field of chemical copper plating, and in particular to a horizontal chemical copper plating solution and a preparation method thereof. A horizontal chemical copper plating solution, measured by mass concentration, comprises the following raw materials: 5-8 g / L of copper sulfate pentahydrate, 18-22 g / L of a reducing agent, 2-3 g / L of 1-benzyl-3-methylimidazolinol, 0.01-0.03 g / L of an accelerator, 30-35 g / L of a complexing agent, 20-25 g / L of a buffer, 0.01-0.03 g / L of a stabilizer, 8-10 g / L of an anti-wear agent, 0.005-0.008 g / L of a surfactant, 0.1-0.3 g / L of an adhesion stabilizer, and the remainder is deionized water, wherein the reducing agent is prepared by mixing sodium borohydride, hydroxyl sulfate, and pyrrolidine tetrafluoroborate in a mass ratio of 2:3:1. The horizontal chemical copper plating solution of the present application has the advantages of fast deposition speed, excellent surface quality, superior low-temperature performance, improved wear resistance, and good plating solution stability. It can effectively improve the efficiency of the chemical copper plating process and the performance of the coating, and meet the needs of various industrial applications.

Description

Technical Field

[0001] The present application relates to the technical field of chemical copper plating, and in particular to a horizontal chemical copper plating solution and a preparation method thereof. Background Art

[0002] Chemical copper is widely used in chemical production. It first appeared in 1957 when Cahill published the first chemical copper plating solution similar to modern ones. The plating solution was alkaline copper tartaric acid plating solution and formaldehyde was the reducing agent. With the development of printed circuit boards, a huge market has been provided for the development of chemical copper plating technology. In the production of printed circuit boards, chemical copper plating is used to precipitate copper as the wall surface of the through hole and the basic circuit path. Chemical copper plating is also suitable for the decorative plastic industry, where copper, nickel, gold, silver and other metals are deposited on non-conductive surfaces as a base as needed.

[0003] Chemical copper plating includes horizontal line chemical copper plating and vertical line chemical copper plating. When the horizontal line chemical copper plating is operated, the substrate is placed horizontally. Therefore, compared with the vertical line chemical copper plating, the horizontal line chemical copper plating can solve the defects such as uneven coating of fine pore diameter of multilayer board, and can well improve the production environment, realize continuous automatic mass production operation, etc. At present, chemical copper plating technology has been widely used in the manufacturing process of printed circuit boards. However, the traditional chemical copper plating solution has problems such as poor coating uniformity, slow deposition speed, poor stability, poor wear resistance and poor bonding force during horizontal electroplating, which affects the quality and production efficiency of printed circuit boards. Summary of the invention

[0004] The purpose of the present application is to provide a horizontal chemical copper plating solution and a preparation method thereof in view of the deficiencies in the current technology. The horizontal chemical copper plating solution of the present application has the advantages of fast deposition speed, good plating solution stability, and the obtained copper plating layer is dense, flat and uniform, has high ductility, good coating adhesion, and high wear resistance, thereby meeting the requirements of functional chemical copper plating.

[0005] In a first aspect, the present application provides a horizontal chemical copper plating solution, which adopts the following technical solution:

[0006] A horizontal chemical copper plating solution comprises the following raw materials, measured by mass concentration: 5-8 g / L of copper sulfate pentahydrate, 18-22 g / L of a reducing agent, 2-3 g / L of 1-benzyl-3-methylimidazolinol, 0.01-0.03 g / L of an accelerator, 30-35 g / L of a complexing agent, 20-25 g / L of a buffer, 0.01-0.03 g / L of a stabilizer, 8-10 g / L of an anti-wear agent, 0.005-0.008 g / L of a surfactant, 0.1-0.3 g / L of an adhesion stabilizer, and the remainder being deionized water.

[0007] By adopting the above technical scheme, copper sulfate pentahydrate plays the role of supplying copper ions in the horizontal chemical copper plating solution and is the main source of copper plating. The role of the reducing agent is to reduce copper ions into solid copper and deposit it on the surface of the substrate, wherein the composition of sodium borohydride, hydroxyl sulfate and pyrrolidine tetrafluoroborate has good reducing performance. 1-benzyl-3-methylimidazolinol as an auxiliary agent is conducive to increasing the deposition rate of copper and can also improve the quality of the copper plating. The accelerator helps to accelerate the deposition rate and improve the glossiness of the coating. The complexing agent can form a complex with copper ions, which helps to increase the deposition rate and stability. The buffer can adjust the pH value of the plating solution and maintain the stability of the plating solution. The stabilizer can make the plating solution stable for a long time to avoid abnormal reactions. The anti-wear agent can increase the wear resistance of the copper plating. The surfactant helps to reduce the surface tension and make the liquid easier to be evenly distributed on the surface of the substrate. The adhesion stabilizer helps to enhance the adhesion between the plating layer and the substrate. The synergistic effect between various raw materials can make the horizontal chemical copper plating solution have the advantages of rapid deposition, good stability, and high coating quality, thus meeting the requirements of functional chemical copper plating.

[0008] Preferably, the reducing agent is prepared by mixing sodium borohydride, hydroxyl sulfate and pyrrolidine tetrafluoroborate in a mass ratio of 2:3:1.

[0009] By adopting the above technical scheme, the mixed formula of sodium borohydride, hydroxyl sulfate and pyrrolidine tetrafluoroborate can effectively promote the reduction reaction of copper, so that copper ions can be quickly reduced and deposited rapidly, thereby realizing a high-speed chemical copper plating process. The three reducing agents are mixed to ensure the compactness, flatness and uniformity of the copper plating layer. Hydroxyl sulfate, as a high-quality reducing agent, can effectively reduce the precipitation of hydrogen and improve the copper deposition quality, while the addition of pyrrolidine tetrafluoroborate can improve the low-temperature performance of the copper plating solution and further improve the quality of the copper plating layer. In general, the synergistic effect of sodium borohydride, hydroxyl sulfate and pyrrolidine tetrafluoroborate makes the horizontal chemical copper plating solution optimized in terms of deposition speed, bath stability and copper plating layer quality, thereby improving the performance and efficiency of the copper plating solution.

[0010] Preferably, the preparation method of the pyrrolidine tetrafluoroborate is as follows: according to molar fractions, 1 part of 1,4-dichlorobutane, 1.2 parts of diethylamine, 1 part of sodium carbonate, and 1 part of tetrafluoroboric acid are added to 10 parts of acetonitrile, heated to 92° C. and reacted for 18-20 hours, cooled to room temperature to obtain a reaction solution, the reaction solution is filtered to obtain a filtrate, the filtrate is concentrated under reduced pressure, and then 10 parts of anhydrous ethanol is added for recrystallization, and a filter cake is obtained after filtration, and the filter cake is vacuum dried to constant weight to obtain pyrrolidine tetrafluoroborate.

[0011] By adopting the above technical scheme, the prepared pyrrolidine tetrafluoroborate plays multiple roles in the horizontal chemical copper plating solution: pyrrolidine tetrafluoroborate can work together with sodium borohydride and hydroxyl sulfate to play a reducing role, synergistically promoting the reduction of copper ions in the plating solution to solid copper and deposit on the surface of the substrate. The presence of pyrrolidine tetrafluoroborate can improve the stability of the horizontal chemical copper plating solution in a low temperature environment and reduce the influence of the coating quality at low temperatures. Pyrrolidine tetrafluoroborate can improve the plating effect of the copper plating solution, making the copper plating layer more dense, flat and uniform. In the preparation method, 1,4-dichlorobutane, diethylamine, sodium carbonate, and tetrafluoroboric acid react in acetonitrile to form pyrrolidine tetrafluoroborate through a specific molar ratio and reaction conditions. This method not only ensures the efficient progress of the reaction, but also prepares high-purity pyrrolidine tetrafluoroborate through subsequent filtration, drying and other steps. In general, the role of pyrrolidine tetrafluoroborate in horizontal chemical copper plating solution and its preparation method comprehensively play multiple functions such as improving plating effect, improving copper plating quality and stability, and promote the overall performance improvement of horizontal chemical copper plating solution.

[0012] Preferably, the wear-resistant agent is copper-plated tungsten carbide, and its preparation method comprises the following steps:

[0013] S31, pretreatment: 10g tungsten carbide is added to 500mL of 50g / L NaOH solution and ultrasonically stirred for 20-30min;

[0014] S32. Surface chemical copper plating: Mix 1L of 12g / L CuSO4·5H2O solution and 1L of 38g / L EDTA-2Na solution, add NaOH to adjust the pH to 12.5, then add the pretreated tungsten carbide and stir evenly, finally add 1L of 15g / L sodium hypophosphite solution, and continue stirring at 60°C for 5h; then collect by centrifugation, wash the collected particles with deionized water to neutrality, and vacuum dry at 50°C for 6-8h to obtain copper-plated tungsten carbide.

[0015] By adopting the above technical scheme, in the above-mentioned horizontal chemical copper plating solution, the use of tungsten carbide as a wear-resistant agent is to improve the wear resistance of the copper-plated layer, and this purpose is achieved through its compatibility with the copper layer and uniform distribution in the copper-plated layer. Tungsten carbide is added to the copper plating solution as a wear-resistant agent and can be more evenly dispersed in the copper-plated layer. It gives the copper-plated layer a certain preferred orientation of the enhanced phase, thereby improving the overall wear resistance of the copper-plated layer and extending the service life of the copper-plated layer. Copper-plated tungsten carbide is more evenly deposited and distributed in the copper-plated layer, and has good compatibility with the copper layer, which will not affect the performance of the copper layer, but further enhances the wear resistance of the copper layer. In the preparation method, the preparation of tungsten carbide includes two steps: pretreatment and surface chemical copper plating. Through this preparation method, tungsten carbide is successfully integrated into the horizontal chemical copper plating solution system, playing an important role in improving wear resistance.

[0016] Preferably, the stabilizer is prepared by mixing 2,2'-bipyridine, potassium hexacyanoferrate and allylthiourea in a mass ratio of 2:3:0.1-0.2.

[0017] By adopting the above technical scheme, the main functions of the stabilizer 2,2'-bipyridine, potassium hexacyanoferrate and propylene thiourea are to prevent adverse reactions in the horizontal chemical copper plating solution and maintain the stability of the plating solution. 2,2'-bipyridine and propylene thiourea can effectively inhibit the occurrence of oxidation reactions and extend the service life of the plating solution. At the same time, potassium hexacyanoferrate can stabilize copper ions as a complexing agent, increase the deposition rate of copper, and further optimize the quality of the copper plating layer. These three stabilizers can better improve the performance of the copper plating solution through reasonable proportions and synergistic effects, so that the prepared copper plating layer is more dense, uniform and wear-resistant.

[0018] Preferably, the accelerator is prepared by mixing triethanolamine and 2-aminopyridine in a mass ratio of 3: 1. By adopting the above technical solution, the accelerator, as an important component in the horizontal chemical copper plating solution, plays a role in promoting reaction and accelerating deposition speed, which is conducive to the rapid film formation of copper and the uniformity of the coating. The accelerator is made by mixing triethanolamine and 2-aminopyridine, and through their characteristic matching, the reaction speed can be increased and the deposition process of copper can be promoted. Specifically, triethanolamine, as one of the accelerators, can provide alkaline conditions in horizontal chemical copper plating, neutralize acidic substances, promote the reduction reaction, thereby increasing the reduction rate of copper ions and accelerating the deposition rate of copper. On the other hand, 2-aminopyridine, as the second component of the accelerator, can provide ligand coordination, help complexing agents to stabilize copper ions more effectively, further accelerate the deposition rate of copper, improve the reactivity of the plating solution and the quality and performance of the copper coating obtained. Therefore, the synergistic effect of the accelerator in the horizontal chemical copper plating solution makes the reaction more efficient and smooth, and the deposition rate of copper is faster, so that a copper coating with better quality and better performance can be obtained, which meets the requirements of functional chemical copper plating.

[0019] Preferably, the complexing agent is prepared by mixing potassium sodium tartrate and tetrahydroxypropylethylenediamine in a mass ratio of 5:1.

[0020] By adopting the above technical scheme, the complexing agent plays an important role in the horizontal chemical copper plating solution, and has two main functions, one is to increase the deposition rate of copper, and the other is to stabilize the plating solution. The complexing agent is composed of potassium sodium tartrate and tetrahydroxypropyl ethylenediamine. Through their characteristic matching, these two functions can be better achieved, and there is a synergistic effect. First, potassium sodium tartrate, as one of the components of the complexing agent, mainly plays the role of forming a complex with copper ions, increases the ion concentration of copper in the plating solution, and increases the deposition rate of copper. This makes the formed copper coating more uniform and dense, and improves the quality of the coating. At the same time, potassium sodium tartrate also helps to maintain an appropriate pH value in the plating solution and maintain the stability of the plating solution. Secondly, tetrahydroxypropyl ethylenediamine, as another component of the complexing agent, also has the function of forming a complex, increases the deposition rate of copper, and stabilizes the plating solution to a certain extent. By mixing with potassium sodium tartrate, the two complexing agents work together to improve the complexing effect, further accelerate the deposition rate of copper, improve the density and uniformity of the coating, and improve the overall stability. In general, potassium sodium tartrate and tetrahydroxypropylethylenediamine act synergistically as complexing agents in horizontal chemical copper plating solution. Their combined action makes the deposition speed faster, the copper plating layer denser and more uniform, while maintaining the stability of the plating solution, meeting the requirements of functional chemical copper plating.

[0021] Preferably, the adhesion stabilizer is prepared by mixing sodium 2-thiophene propene and sodium 2-furan acrylate in a mass ratio of 5:1-2.

[0022] By adopting the above technical scheme, the adhesion stabilizer, as an important component of the horizontal chemical copper plating solution, plays a role in protecting and enhancing the adhesion of the coating in the plating solution. The adhesion stabilizer is prepared by mixing 2-thiophene propylene sodium and 2-furan acrylate sodium. First, 2-thiophene propylene sodium and 2-furan acrylate sodium, as one of the components of the adhesion stabilizer, can react with the surface of the copper substrate to form an organic film, thereby improving the adhesion of the copper coating. This can effectively prevent the coating from peeling off and falling off during use, and enhance the stability and durability of the coating. Secondly, by mixing 2-thiophene propylene sodium and 2-furan acrylate sodium, the two components may react to form a more uniform and dense protective film, further improving the contact strength and adhesion of the copper coating, making the coating more stable. Therefore, in the horizontal chemical copper plating solution, the role of the adhesion stabilizer is mainly reflected in improving the adhesion of the coating. Through the synergistic effect of sodium 2-thiophenepropene and sodium 2-furanpropene, the protective film formation and performance improvement are further enhanced, thereby meeting the requirements of functional chemical copper plating and making the coating have better wear resistance, flatness and consistency.

[0023] Preferably, the surfactant is polyvinyl pyrrolidone.

[0024] Preferably, the buffer is one of sodium carbonate and potassium carbonate.

[0025] In a second aspect, the present application provides a method for preparing a horizontal chemical copper plating solution, using the following technical solution:

[0026] As a general technical concept, the present application also provides a method for preparing the above-mentioned horizontal chemical copper plating solution, comprising the following steps: adding copper sulfate pentahydrate, a reducing agent, 1-benzyl-3-methylimidazolinol, an accelerator, a complexing agent, a buffer, a stabilizer, an anti-wear agent, a surfactant and an adhesion stabilizer to deionized water, and stirring for 20-30 minutes to obtain a horizontal chemical copper plating solution.

[0027] In summary, the beneficial technical effects of this application are:

[0028] 1. Rapid deposition: Through the combination of a specific reducing agent and 1-benzyl-3-methylimidazolinol, the deposition rate of copper ions can be increased, so that copper can be quickly reduced and deposited to obtain a high-speed chemical copper plating layer.

[0029] 2. Excellent surface quality: The copper coating obtained is dense, flat and uniform, with high ductility, good coating adhesion and wear resistance, meeting the requirements of functional chemical copper plating.

[0030] 3. Excellent low-temperature performance: By adding pyrrolidine tetrafluoroborate, the low-temperature resistance of the horizontal chemical copper plating solution is improved, and the density and flatness uniformity of the copper plating layer are improved.

[0031] 4. Improved wear resistance of the coating: Using tungsten carbide as a wear-resistant agent can be more evenly dispersed in the copper coating and give the copper coating a preferred orientation of the reinforcement phase, thereby improving the wear resistance of the copper coating.

[0032] 5. Good stability of the plating solution: The addition of complexing agents and buffers makes the plating solution have good stability, ensuring the stability and reliability of the entire chemical copper plating process. DETAILED DESCRIPTION

[0033] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0034] Preparation Example 1 Preparation of pyrrolidine tetrafluoroborate

[0035] The preparation method of pyrrolidine tetrafluoroborate is as follows: according to the molar fractions, 1 mol of 1,4-dichlorobutane, 1.2 mol of diethylamine, 1 mol of sodium carbonate and 1 mol of tetrafluoroboric acid are added to 10 mol of acetonitrile, heated to 92°C and reacted for 19 hours, cooled to room temperature to obtain a reaction liquid, the reaction liquid is filtered to obtain a filtrate, the filtrate is concentrated under reduced pressure, 10 mol of anhydrous ethanol is added to recrystallize, a filter cake is obtained after filtration, and the filter cake is vacuum dried to constant weight to obtain pyrrolidine tetrafluoroborate.

[0036] The pyrrolidine tetrafluoroborate prepared above was used in various examples.

[0037] Preparation Example 2 Preparation of copper-plated tungsten carbide

[0038] The wear-resistant agent is copper-plated tungsten carbide, and its preparation method comprises the following steps:

[0039] S31, pretreatment: 10g of tungsten carbide was added into 500mL of 50g / L NaOH solution and ultrasonically stirred for 25min;

[0040] S32. Surface chemical copper plating: Mix 1L of 12g / L CuSO4·5H2O solution and 1L of 38g / L EDTA-2Na solution, add NaOH to adjust the pH to 12.5, then add the pretreated tungsten carbide and stir evenly, finally add 1L of 15g / L sodium hypophosphite solution, and continue stirring at 60°C for 5h; then collect by centrifugation, wash the collected particles with deionized water to neutrality, and vacuum dry at 50°C for 7h to obtain copper-plated tungsten carbide.

[0041] The copper-plated tungsten carbide prepared above is applied to various embodiments.

[0042] Example 1

[0043] A horizontal chemical copper plating solution, measured by mass concentration, includes the following raw materials: 5g / L copper sulfate pentahydrate, 18g / L reducing agent, 2g / L 1-benzyl-3-methylimidazolinol, 0.01g / L accelerator, 30g / L complexing agent, 20g / L sodium carbonate, 0.01g / L stabilizer, 8g / L copper-plated tungsten carbide, 0.005g / L polyvinyl pyrrolidone, 0.1g / L adhesion stabilizer, and the rest is deionized water, wherein the reducing agent is sodium borohydride, Hydroxyl sulfate and pyrrolidine tetrafluoroborate are mixed in a mass ratio of 2:3:1, the stabilizer is mixed in a mass ratio of 2,2'-bipyridine, potassium hexacyanoferrate and allylthiourea in a mass ratio of 2:3:0.1, the accelerator is mixed in a mass ratio of 3:1 for triethanolamine and 2-aminopyridine, the complexing agent is mixed in a mass ratio of 5:1 for potassium sodium tartrate and tetrahydroxypropylethylenediamine, and the adhesion stabilizer is mixed in a mass ratio of 5:1 for sodium 2-thiophene propene and sodium 2-furan acrylate;

[0044] The preparation method of the above-mentioned horizontal chemical copper plating solution comprises the following steps: adding copper sulfate pentahydrate, a reducing agent, 1-benzyl-3-methylimidazolinol, an accelerator, a complexing agent, sodium carbonate, a stabilizer, copper-plated tungsten carbide, polyvinyl pyrrolidone and an adhesion stabilizer into deionized water, and stirring for 20 minutes to obtain a horizontal chemical copper plating solution.

[0045] Example 2

[0046] A horizontal chemical copper plating solution, measured by mass concentration, includes the following raw materials: 8 g / L of copper sulfate pentahydrate, 22 g / L of a reducing agent, 3 g / L of 1-benzyl-3-methylimidazolinol, 0.03 g / L of an accelerator, 35 g / L of a complexing agent, 25 g / L of potassium carbonate, 0.03 g / L of a stabilizer, 10 g / L of copper-plated tungsten carbide, 0.008 g / L of polyvinyl pyrrolidone, 0.3 g / L of an adhesion stabilizer, and the remainder is deionized water, wherein the reducing agent is sodium borohydride, Hydroxyl sulfate and pyrrolidine tetrafluoroborate are mixed in a mass ratio of 2:3:1, the stabilizer is mixed in a mass ratio of 2,2'-bipyridine, potassium hexacyanoferrate and allylthiourea in a mass ratio of 2:3:0.2, the accelerator is mixed in a mass ratio of 3:1 for triethanolamine and 2-aminopyridine, the complexing agent is mixed in a mass ratio of 5:1 for potassium sodium tartrate and tetrahydroxypropylethylenediamine, and the adhesion stabilizer is mixed in a mass ratio of 5:2 for sodium 2-thiophene propene and sodium 2-furan acrylate;

[0047] The preparation method of the above-mentioned horizontal chemical copper plating solution comprises the following steps: adding copper sulfate pentahydrate, a reducing agent, 1-benzyl-3-methylimidazolinol, an accelerator, a complexing agent, potassium carbonate, a stabilizer, copper-plated tungsten carbide, polyvinyl pyrrolidone and an adhesion stabilizer into deionized water, and stirring for 30 minutes to obtain a horizontal chemical copper plating solution.

[0048] Example 3

[0049] A horizontal chemical copper plating solution, measured by mass concentration, includes the following raw materials: 7 g / L copper sulfate pentahydrate, 20 g / L reducing agent, 2.5 g / L 1-benzyl-3-methylimidazolinol, 0.02 g / L accelerator, 33 g / L complexing agent, 22 g / L sodium carbonate, 0.02 g / L stabilizer, 9 g / L copper-plated tungsten carbide, 0.006 g / L polyvinyl pyrrolidone, 0.2 g / L adhesion stabilizer, and the rest is deionized water, wherein the reducing agent is sodium borohydride, sulfur Acid hydroxylamine and pyrrolidine tetrafluoroborate are mixed in a mass ratio of 2:3:1, the stabilizer is mixed with 2,2'-bipyridine, potassium hexacyanoferrate and allylthiourea in a mass ratio of 2:3:0.15, the accelerator is mixed with triethanolamine and 2-aminopyridine in a mass ratio of 3:1, the complexing agent is mixed with potassium sodium tartrate and tetrahydroxypropyl ethylenediamine in a mass ratio of 5:1, and the adhesion stabilizer is mixed with sodium 2-thiophene propene and sodium 2-furan acrylate in a mass ratio of 5:1.5;

[0050] The preparation method of the above-mentioned horizontal chemical copper plating solution comprises the following steps: adding copper sulfate pentahydrate, a reducing agent, 1-benzyl-3-methylimidazolinol, an accelerator, a complexing agent, sodium carbonate, a stabilizer, copper-plated tungsten carbide, polyvinyl pyrrolidone and an adhesion stabilizer into deionized water, and stirring for 25 minutes to obtain a horizontal chemical copper plating solution.

[0051] Comparative Example 1

[0052] The same as Example 3, except that the reducing agent is prepared by mixing sodium borohydride and pyrrolidine tetrafluoroborate in a mass ratio of 5:1.

[0053] Comparative Example 2

[0054] The same as Example 3, except that the reducing agent is prepared by mixing sodium borohydride and hydroxyl sulfate in a mass ratio of 2:3.

[0055] Comparative Example 3

[0056] The same as Example 3, except that the stabilizer is prepared by mixing 2,2'-bipyridine and potassium hexacyanoferrate in a mass ratio of 2:3.

[0057] Comparative Example 4

[0058] The same as Example 3, except that the stabilizer is prepared by mixing 2,2'-bipyridine and allylthiourea in a mass ratio of 5:0.15.

[0059] Comparative Example 5

[0060] The same as Example 3, except that the stabilizer is prepared by mixing potassium hexacyanoferrate and allylthiourea in a mass ratio of 5:0.15.

[0061] Comparative Example 6

[0062] The same as Example 3, except that the accelerator is triethanolamine.

[0063] Comparative Example 7

[0064] The same as Example 3, except that the accelerator is 2-aminopyridine.

[0065] Comparative Example 8

[0066] The same as Example 3, except that the complexing agent is potassium sodium tartrate.

[0067] Comparative Example 9

[0068] The same as Example 3, except that the complexing agent is tetrahydroxypropylethylenediamine.

[0069] Comparative Example 10

[0070] The same as Example 3, except that an equal amount of tungsten carbide is used instead of copper-plated tungsten carbide.

[0071] Performance Testing

[0072] The horizontal chemical copper plating solutions prepared in Examples 1 to 3 and Comparative Examples 1 to 10 were respectively subjected to chemical copper plating. The process conditions were: temperature 33° C., time 30 minutes, the part to be plated was a resin board, and after a conventional chemical copper plating process, the surface was activated with palladium and reduced, and the chemical copper plating process could be directly performed to perform the above-mentioned chemical copper plating. The following tests were performed, and the test results are shown in Table 1.

[0073] 1. Sedimentation rate test: The sedimentation rate is determined by the weight gain method, and the calculation formula is as follows:

[0074] v=(m1-m0)×10000 / (ρ×A×t);

[0075] Where v is the deposition rate, μm / h; m0 and m1 are the mass of the plated part before and after plating, respectively, g; ρ is the relative density of copper, 8.93 g / cm 3 ; A is the surface area of ​​the plated part, cm 2 ; t is the plating time, h;

[0076] 2. Ductility test: Use titanium coated with iridium oxide anode, and polished stainless steel plate as cathode, electroplating 50-80 microns, baking at 120℃ for 2h, peeling off the coating, making it into 1cm wide strips, and testing the elongation and tensile strength of the coating when it breaks on a tensile test machine. The elongation requirement is >18%, the higher the better, and the tensile strength requirement is 200-500MPa;

[0077] 3. Adhesion test: Use the hundred-grid test method, use 3M 610 tape to tear, no peeling is OK, and peeling is NG;

[0078] 4. Plating solution stability test: Since it takes a long time for the plating solution to decompose naturally, in order to shorten the experimental time, an accelerated method is generally used. The present invention uses a palladium chloride accelerated test to test the stability of the plating solution: add 15mL PdCl2 (0.18g / L) to 50mL of the plating solution at a temperature of 60°C, and record the decomposition time of the plating solution, that is, the time required to produce a large amount of red copper powder and hydrogen;

[0079] 5. Wear rate: The wear amount was tested using a UMT-3 friction tester. During the test, the load was 80N, the friction speed was 800rpm, and the friction time was 2min. After the friction test, an analytical balance was used to measure the mass of the plated parts before and after each friction test, and then the mass was divided by the contact area to calculate the wear rate.

[0080] Table 1 Performance test

[0081]

[0082]

[0083] Analyzing the data in Table 1, we can see that:

[0084] 1) The horizontal chemical copper plating solution prepared in Example 1 to Example 3 has the advantages of fast deposition speed, good solution stability, dense, flat and uniform copper plating layer, high ductility, good coating adhesion and high wear resistance, etc., which meets the requirements of functional chemical copper plating.

[0085] 2) The performance comparison analysis of the horizontal chemical copper plating solution prepared in combination with Example 3 and Comparative Examples 1-2 shows that the reducing agent is prepared by mixing sodium borohydride, hydroxyl sulfate and pyrrolidine tetrafluoroborate in a mass ratio of 2:3:1, and the synergistic effect between them can improve the deposition rate and coating quality of the horizontal chemical copper plating solution.

[0086] 3) The performance comparison analysis of the horizontal chemical copper plating solution prepared in combination with Example 3 and Comparative Examples 3 to Comparative Examples 5 shows that the stabilizer is prepared by mixing 2,2'-bipyridine, potassium hexacyanoferrate and allylthiourea in a mass ratio of 2:3:0.15. By controlling the reasonable ratio of the three stabilizers and utilizing the synergistic effect between them, the stability of the copper plating solution can be better improved, making the prepared copper coating more dense, uniform and wear-resistant.

[0087] 4) The performance comparison analysis of the horizontal chemical copper plating solution prepared in combination with Example 3 and Comparative Examples 6-7 shows that the accelerator is prepared by mixing triethanolamine and 2-aminopyridine in a mass ratio of 3:1. Through their characteristic matching, the reaction speed can be increased and the copper deposition process can be promoted. The synergistic effect of the accelerator in the horizontal chemical copper plating solution makes the reaction more efficient and smooth, and the copper deposition rate is faster, so that a copper coating with better quality and better performance can be obtained, which meets the requirements of functional chemical copper plating.

[0088] 5) The performance comparison analysis of the horizontal chemical copper plating solution prepared in combination with Example 3 and Comparative Examples 8-9 shows that the complexing agent is prepared by mixing potassium sodium tartrate and tetrahydroxypropyl ethylenediamine in a mass ratio of 5: 1. Utilizing the synergistic effect between them, the two complexing agents work together to improve the complexing effect, further accelerate the deposition rate of copper, improve the compactness and uniformity of the coating, and simultaneously enhance the overall stability. The role and synergy of potassium sodium tartrate and tetrahydroxypropyl ethylenediamine as complexing agents in the horizontal chemical copper plating solution. They work together to make the deposition rate faster, the copper coating more compact and uniform, while maintaining the stability of the plating solution, meeting the requirements of functional chemical copper plating.

[0089] 6) The performance comparison analysis of the horizontal chemical copper plating solution prepared in combination with Example 3 and Comparative Example 10 shows that the copper-plated tungsten carbide prepared in the present application achieves compatibility with the copper layer and is evenly distributed in the copper layer. Copper-plated tungsten carbide is added to the copper plating solution as a wear-resistant agent and can be more evenly dispersed in the copper layer. It gives the copper layer a certain preferred orientation of the enhanced phase, thereby improving the overall wear resistance of the copper layer and extending the service life of the copper layer.

[0090] The above embodiments are only used to explain the technical solutions of the present application rather than to limit them. Although the above embodiments provide a specific description of the present application, relevant technical personnel should understand that the specific implementation modes of the present invention can still be modified or replaced by equivalents, and any modifications and equivalent replacements that do not depart from the spirit and scope of the present application should be included in the scope of protection of the present application.

Claims

1. A horizontal chemical copper plating solution, characterized in that: The preparation raw materials include, by mass concentration, 5-8 g / L of copper sulfate pentahydrate, 18-22 g / L of reducing agent, 2-3 g / L of 1-benzyl-3-methylimidazolinol, 0.01-0.03 g / L of accelerator, 30-35 g / L of complexing agent, 20-25 g / L of buffer, 0.01-0.03 g / L of stabilizer, 8-10 g / L of anti-wear agent, 0.005-0.008 g / L of surfactant, 0.1-0.3 g / L of adhesion stabilizer, and the rest is deionized water, wherein the reducing agent is prepared by mixing sodium borohydride, hydroxyl sulfate and pyrrolidine tetrafluoroborate in a mass ratio of 2:3:1; The preparation method of pyrrolidine tetrafluoroborate is as follows: according to molar fractions, 1 part of 1,4-dichlorobutane, 1.2 parts of diethylamine, 1 part of sodium carbonate, and 1 part of tetrafluoroboric acid are added to 10 parts of acetonitrile, heated to 92° C. and reacted for 18-20 hours, cooled to room temperature to obtain a reaction solution, the reaction solution is filtered to obtain a filtrate, the filtrate is concentrated under reduced pressure, and then 10 parts of anhydrous ethanol is added for recrystallization, and a filter cake is obtained after filtration, and the filter cake is vacuum dried to constant weight to obtain pyrrolidine tetrafluoroborate; The wear-resistant agent is copper-plated tungsten carbide, and its preparation method comprises the following steps: S31, pretreatment: 10g tungsten carbide is added to 500mL of 50g / L NaOH solution and ultrasonically stirred for 20-30min; S32, surface chemical copper plating: after mixing 1L of 12g / L CuSO4·5H2O solution and 1L of 38g / L EDTA-2Na solution, add NaOH to adjust the pH to 12.5, then add the pretreated tungsten carbide and stir evenly, finally add 1L of 15g / L sodium hypophosphite solution, and continue stirring at 60°C for 5h; then collect by centrifugation, wash the collected particles with deionized water to neutrality, and vacuum dry at 50°C for 6-8h to obtain copper-plated tungsten carbide; The stabilizer is prepared by mixing 2,2'-bipyridine, potassium hexacyanoferrate and allylthiourea in a mass ratio of 2:3:0.1-0.2; The accelerator is prepared by mixing triethanolamine and 2-aminopyridine in a mass ratio of 3:1; The complexing agent is prepared by mixing potassium sodium tartrate and tetrahydroxypropylethylenediamine in a mass ratio of 5:1; The adhesion stabilizer is prepared by mixing sodium 2-thiophene propene and sodium 2-furan acrylate in a mass ratio of 5:1-2; The surfactant is polyvinyl pyrrolidone; The buffer is one of sodium carbonate and potassium carbonate.

2. A method for preparing a horizontal chemical copper plating solution according to claim 1, characterized in that: include: Copper sulfate pentahydrate, a reducing agent, 1-benzyl-3-methylimidazolinol, an accelerator, a complexing agent, a buffer, a stabilizer, an anti-wear agent, a surfactant and an adhesion stabilizer are added into deionized water and stirred for 20-30 minutes to obtain a horizontal chemical copper plating solution.

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