Environment-friendly pulse electroplating liquid and preparation method thereof

Abstract

The invention provides an environment-friendly pulse electroplating solution. The environment-friendly pulse electroplating solution is prepared from the following components: 65 to 85 parts of copper sulfate pentahydrate, 80 to 120 parts of sulfuric acid, 0.4 to 0.8 part of sodium chloride, 0.6 to 0.9 part of triammonium citrate, 0.6 to 1.0 part of polyvinylpyrrolidone, 0.3 to 0.6 part of polyvinyl alcohol, 0.5 to 1.2 parts of nonylphenol polyoxyethylene ether, 0.2 to 0.5 part of sodium sulfosuccinate and 0.1 to 0.3 part of castor oil polyoxyethylene ether. Through synergistic cooperation of all the components, the electroplating liquid has good deep plating capacity and electroplating rate and is environmentally friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of pulse electroplating, and specifically relates to an environmentally friendly pulse electroplating solution and a preparation method thereof. Background Art

[0002] Pulse plating is an advanced electroplating technology that improves the quality and performance of the coating by using intermittent current (i.e. pulse current) during the electroplating process. Compared with ordinary DC plating layers, it has more excellent properties, such as corrosion resistance, wear resistance, high purity, conductivity, welding and anti-discoloration performance, etc. It can greatly save rare and precious metals. Therefore, it is well used in functional electroplating. Common pulse current waveforms include square wave, triangle wave, sawtooth wave, step wave, etc. At present, square wave pulses are mostly used in pulse plating. The existing pulse electroplating has an ideal pulse current waveform, but due to the instability of the pulse power supply quality, the pulse waveform of the pulse power supply in the application cannot be the same as the ideal waveform.

[0003] Pulse plating controls the metal deposition process by changing the current waveform, frequency, on-off ratio, average current density and other parameters. When the current is turned on, the electrochemical polarization increases, and the metal ions near the cathode area are fully deposited; when the current is turned off, the concentration of discharged ions near the cathode area returns to the initial level, the concentration polarization is eliminated, and it is accompanied by phenomena that are beneficial to the recrystallization, adsorption and desorption of the deposited layer. This cyclical process runs through the entire electroplating process and can improve the microstructure of the coating.

[0004] The uniformity and deposition rate of the coating in the existing pulse electroplating technology are not ideal, and the internal stress and porosity are large. At the same time, most of the electroplating solutions used in my country's electroplating industry contain toxic components (such as cyanide in gold plating solutions), and the stability of the electroplating solutions is poor. Improper treatment of electroplating waste liquid will also have a harmful impact on the environment. Summary of the invention

[0005] The invention aims to provide an environmentally friendly pulse electroplating solution and a preparation method thereof. By combining copper sulfate pentahydrate, concentrated sulfuric acid, sodium chloride, triammonium citrate, polyvinyl pyrrolidone, polyvinyl alcohol, nonylphenol polyoxyethylene ether, sodium succinate sulfonate and castor oil polyoxyethylene ether, an electroplating solution with good deep plating ability, electroplating rate, good stability and environmental friendliness is obtained.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: An environmentally friendly pulse electroplating solution comprises the following components in parts by weight: 65-85 parts of copper sulfate pentahydrate, 80-120 parts of sulfuric acid, 0.4-0.8 parts of sodium chloride, 0.6-0.9 parts of triammonium citrate, 0.6-1.0 parts of polyvinyl pyrrolidone, 0.3-0.6 parts of polyvinyl alcohol, 0.5-1.2 parts of nonylphenol polyoxyethylene ether, 0.2-0.5 parts of sodium succinate sulfonate and 0.1-0.3 parts of castor oil polyoxyethylene ether.

[0007] Preferably, the composition comprises the following components: 70-80 parts of copper sulfate pentahydrate, 90-110 parts of sulfuric acid, 0.5-0.7 parts of sodium chloride, 0.7-0.9 parts of triammonium citrate, 0.7-0.9 parts of polyvinyl pyrrolidone, 0.4-0.6 parts of polyvinyl alcohol, 0.5-1.0 parts of nonylphenol polyoxyethylene ether, 0.3-0.4 parts of sodium succinate sulfonate and 0.2-0.3 parts of castor oil polyoxyethylene ether.

[0008] Preferably, the following components are included in parts by weight: 75 parts of copper sulfate pentahydrate, 100 parts of sulfuric acid, 0.6 parts of sodium chloride, 0.8 parts of triammonium citrate, 0.8 parts of polyvinyl pyrrolidone, 0.5 parts of polyvinyl alcohol, 0.7 parts of nonylphenol polyoxyethylene ether, 0.4 parts of sodium succinate sulfonate and 0.2 parts of castor oil polyoxyethylene ether.

[0009] A method for preparing an environmentally friendly pulse plating solution comprises the following steps: S1: In parts by weight, 65-85 parts of copper sulfate pentahydrate, 80-120 parts of concentrated sulfuric acid with a mass fraction of 98% and 0.4-0.8 parts of sodium chloride are mixed, and stirred at a temperature of 50-70°C and a speed of 300-400r / min for 30-60min to obtain a mixed solution A; S2: Mix 0.6-1.0 parts of polyvinyl pyrrolidone, 0.3-0.6 parts of polyvinyl alcohol and 0.5-1.2 parts of nonylphenol polyoxyethylene ether by weight, and stir at a temperature of 40-60°C and a speed of 400-600 r / min for 50-80 min to obtain a mixed solution B; S3: Mix 0.6-0.9 parts of triammonium citrate, 0.2-0.5 parts of sodium succinate sulfonate and 0.1-0.3 parts of castor oil polyoxyethylene ether by weight, and stir at a temperature of 80-110° C. and a speed of 500-800 r / min for 40-70 min to obtain a mixed solution C; S4: Take the mixed solution A described in step S1, the mixed solution B described in step S2 and the mixed solution C described in step S3, and perform ultrasonic treatment at a temperature of 35-55° C. and a power of 1500-2500 W for 25-45 minutes to obtain an environmentally friendly pulse plating solution.

[0010] Preferably, step S1 is specifically as follows: by weight, 73 parts of copper sulfate pentahydrate, 110 parts of concentrated sulfuric acid with a mass fraction of 98% and 0.6 parts of sodium chloride are mixed, and stirred at a temperature of 65° C. and a speed of 350 r / min for 45 minutes to obtain a mixed solution A.

[0011] Preferably, step S2 is specifically as follows: 0.7-0.9 parts of polyvinyl pyrrolidone, 0.4-0.6 parts of polyvinyl alcohol and 0.5-1.0 parts of nonylphenol polyoxyethylene ether are mixed, and stirred at a temperature of 45-60° C. and a speed of 400-500 r / min for 60-70 min to obtain a mixed solution B.

[0012] Preferably, step S2 is specifically as follows: 0.7 parts of polyvinyl pyrrolidone, 0.5 parts of polyvinyl alcohol and 0.8 parts of nonylphenol polyoxyethylene ether are mixed, and stirred at a temperature of 55° C. and a speed of 450 r / min for 65 minutes to obtain a mixed solution B.

[0013] Preferably, 0.8 parts of triammonium citrate, 0.4 parts of sodium succinate sulfonate and 0.2 parts of castor oil polyoxyethylene ether are mixed, and stirred at a temperature of 100° C. and a speed of 650 r / min for 55 minutes to obtain a mixed solution C.

[0014] Preferably, step S4 is specifically as follows: taking the mixed solution A described in step S1, the mixed solution B described in step S2 and the mixed solution C described in step S3, and ultrasonically treating them at a temperature of 40-50° C. and a power of 1800-2200 W for 30-40 minutes to obtain an environmentally friendly pulse plating solution.

[0015] Preferably, the mixed solution A in step S1, the mixed solution B in step S2 and the mixed solution C in step S3 are ultrasonically treated at a temperature of 42° C. and a power of 2000 W for 35 minutes to obtain an environmentally friendly pulse plating solution.

[0016] Compared with the prior art, the advantages and beneficial effects of the present invention are: 1. The present invention prepares a pulse electroplating solution by using copper sulfate pentahydrate, concentrated sulfuric acid, sodium chloride, triammonium citrate, polyvinyl pyrrolidone, polyvinyl alcohol, nonylphenol polyoxyethylene ether, sodium succinate sulfonate and castor oil polyoxyethylene ether as components. Through the synergistic coordination between the components, the deep plating ability and the electroplating rate are significantly improved, and the stability is good and the environment is friendly.

[0017] 2. Under the action of sodium chloride, copper sulfate pentahydrate, etc., the free chloride ions and copper ions form copper chloride, which will form a copper chloride film with good density on the surface of the substrate during electroplating, inhibiting the electrodeposition of copper; the chloride ions promote the dissolution of the copper anode, enhance the anode activity, prevent the copper anode from passivation, and effectively inhibit the generation of copper powder.

[0018] 3. The present invention adds triammonium citrate, sodium succinate sulfonate and castor oil polyoxyethylene ether, and no columnar directional crystallization is produced during electroplating, which improves the mechanical properties of the electroplated copper layer, reduces the risk of copper layer breakage, and thus improves electroplating stability.

[0019] 4. The present invention adds polyvinyl pyrrolidone, polyvinyl alcohol and nonylphenol polyoxyethylene ether to improve the surface adsorption of the plated parts, make the coating deposition more uniform, and significantly improve the deep plating ability of the coating. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The sources of raw materials of the present invention are as follows: Polyvinyl pyrrolidone was from Shanghai Yuanye Biotechnology Co., Ltd., item number S30268; polyvinyl alcohol was from Sichuan Lai Te Ju Xin Pharmaceutical Excipients Co., Ltd., item number 40; nonylphenol polyoxyethylene ether was from Shanghai Yuanye Biotechnology Co., Ltd., item number S41793; sodium succinate sulfonate was from Shanghai Yuanye Biotechnology Co., Ltd., item number S26111; castor oil polyoxyethylene ether was from Nantong Deyi Chemical Co., Ltd., item number DYTBM / 40.

[0022] Example 1 This embodiment provides a method for preparing an environmentally friendly pulse plating solution, comprising the following steps: S1: Mix 65g of copper sulfate pentahydrate, 80g of 98% concentrated sulfuric acid and 0.4g of sodium chloride, and stir at 50°C and 300r / min for 30min to obtain a mixed solution A; S2: Mix 0.6 g polyvinyl pyrrolidone, 0.3 g polyvinyl alcohol and 0.5 g nonylphenol polyoxyethylene ether, and stir at 40°C and 400 r / min for 50 min to obtain a mixed solution B; S3: 0.6 g of triammonium citrate, 0.2 g of sodium succinate sulfonate and 0.1 g of castor oil polyoxyethylene ether were mixed, and stirred at 80°C and 500 r / min for 40 min to obtain a mixed solution C; S4: Take the mixed solution A described in step S1, the mixed solution B described in step S2 and the mixed solution C described in step S3, and perform ultrasonic treatment at a temperature of 35° C. and a power of 1500 W for 25 minutes to obtain an environmentally friendly pulse plating solution.

[0023] Example 2 This embodiment provides a method for preparing an environmentally friendly pulse plating solution, comprising the following steps: S1: Mix 85g of copper sulfate pentahydrate, 120g of 98% concentrated sulfuric acid and 0.8g of sodium chloride, and stir at 70°C and 400r / min for 60min to obtain a mixed solution A; S2: Mix 1.0 g of polyvinyl pyrrolidone, 0.6 g of polyvinyl alcohol and 1.2 g of nonylphenol polyoxyethylene ether, and stir at 60°C and 600 r / min for 80 min to obtain a mixed solution B; S3: 0.9 g of triammonium citrate, 0.5 g of sodium succinate sulfonate and 0.3 g of castor oil polyoxyethylene ether were mixed, and stirred at a temperature of 110°C and a speed of 800 r / min for 70 min to obtain a mixed solution C; S4: Take the mixed solution A described in step S1, the mixed solution B described in step S2 and the mixed solution C described in step S3, and perform ultrasonic treatment at a temperature of 55° C. and a power of 2500 W for 45 minutes to obtain an environmentally friendly pulse plating solution.

[0024] Example 3 This embodiment provides a method for preparing an environmentally friendly pulse plating solution, comprising the following steps: S1: Mix 73g of copper sulfate pentahydrate, 110g of 98% concentrated sulfuric acid and 0.6g of sodium chloride, and stir at 65°C and 350r / min for 45min to obtain a mixed solution A; S2: Mix 0.7 g polyvinyl pyrrolidone, 0.5 g polyvinyl alcohol and 0.8 g nonylphenol polyoxyethylene ether, and stir at 55°C and 450 r / min for 65 min to obtain a mixed solution B; S3: 0.8 g of triammonium citrate, 0.4 g of sodium succinate sulfonate and 0.2 g of castor oil polyoxyethylene ether were mixed, and stirred at 100°C and 650 r / min for 55 min to obtain a mixed solution C; S4: Take the mixed solution A described in step S1, the mixed solution B described in step S2 and the mixed solution C described in step S3, and perform ultrasonic treatment at a temperature of 42° C. and a power of 2000 W for 35 minutes to obtain an environmentally friendly pulse plating solution.

[0025] Comparative Example 1 The difference between this comparative example and Example 1 is that sodium chloride is not added in step S1, and the other steps are the same.

[0026] Comparative Example 2 The difference between this comparative example and Example 1 is that step S2 is missing, and the other steps are the same.

[0027] Comparative Example 3 The difference between this comparative example and Example 1 is that step S3 is missing, and the other steps are the same.

[0028] Comparative Example 4 The difference between this comparative example and Example 1 is that polyvinyl pyrrolidone is not added in step S2, and the other steps are the same.

[0029] Comparative Example 5 The difference between this comparative example and Example 1 is that sodium succinate sulfonate is not added in step S3, and the other steps are the same.

[0030] Comparative Example 6 The difference between this comparative example and Example 1 is that triammonium citrate is not added in step S3, and the other steps are the same.

[0031] Performance test Take a test board and use the plating solution obtained in each embodiment and comparative example for electroplating. The test board is 3 mm thick and the through hole diameter is 0.2 μm. Composite pulse waveform electroplating is adopted. The forward and reverse current density ratio is 1:20, the forward and reverse pulse width ratio is 10:1, and the phosphor copper plate is used as the anode. The cathode and anode area ratio is 1:1. The electroplating time is 80 minutes. After the electroplating is completed, the test board is rinsed with water, and the surface of the test board is dried with cold wind and the following tests are performed: Deep plating ability test. Make the test board into a metallographic microscope slice, observe and record the thickness of the inner and outer plating layers of the through hole under a 200x microscope, and test the deep plating ability. The calculation formula is: plating thickness ratio = plating thickness inside the through hole / plating thickness outside the through hole × 100%. When the plating thickness ratio is 90% 120%, the deep plating ability is better, and the closer the plating thickness ratio is to 100%, the better the deep plating ability.

[0032] Coating ductility and tensile strength test. According to IPC-TM650-2.4.18 "Test Method for Tensile Strength and Ductility of Copper Foil", the coating of the test board is tested for ductility and tensile strength. The results are shown in the table below: Table 1 Performance test results

[0033] It can be seen from the above performance test results that the deep plating ability, elongation and tensile strength of Examples 1-3 are good and the results are obvious. In particular, the comprehensive performance of Example 3 is the most outstanding. However, since the comparative example does not adopt the necessary technical solution, it is obviously worse than the embodiment in the corresponding performance test. The above experimental results further prove the importance of the technical solution defined in the present invention for its technical effect.

[0034] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An environmentally friendly pulse plating solution, characterized in that: The invention comprises the following components in parts by weight: 65-85 parts of copper sulfate pentahydrate, 80-120 parts of sulfuric acid, 0.4-0.8 parts of sodium chloride, 0.6-0.9 parts of triammonium citrate, 0.6-1.0 parts of polyvinyl pyrrolidone, 0.3-0.6 parts of polyvinyl alcohol, 0.5-1.2 parts of nonylphenol polyoxyethylene ether, 0.2-0.5 parts of sodium succinate sulfonate and 0.1-0.3 parts of castor oil polyoxyethylene ether.

2. An environmentally friendly pulse plating solution according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 70-80 parts of copper sulfate pentahydrate, 90-110 parts of sulfuric acid, 0.5-0.7 parts of sodium chloride, 0.7-0.9 parts of triammonium citrate, 0.7-0.9 parts of polyvinyl pyrrolidone, 0.4-0.6 parts of polyvinyl alcohol, 0.5-1.0 parts of nonylphenol polyoxyethylene ether, 0.3-0.4 parts of sodium succinate sulfonate and 0.2-0.3 parts of castor oil polyoxyethylene ether.

3. The environmentally friendly pulse plating solution according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 75 parts of copper sulfate pentahydrate, 100 parts of sulfuric acid, 0.6 parts of sodium chloride, 0.8 parts of triammonium citrate, 0.8 parts of polyvinyl pyrrolidone, 0.5 parts of polyvinyl alcohol, 0.7 parts of nonylphenol polyoxyethylene ether, 0.4 parts of sodium succinate sulfonate and 0.2 parts of castor oil polyoxyethylene ether.

4. A method for preparing an environmentally friendly pulse plating solution, characterized in that: The steps include: S1: In parts by weight, 65-85 parts of copper sulfate pentahydrate, 80-120 parts of concentrated sulfuric acid with a mass fraction of 98% and 0.4-0.8 parts of sodium chloride are mixed, and stirred at a temperature of 50-70°C and a speed of 300-400r / min for 30-60min to obtain a mixed solution A; S2: Mix 0.6-1.0 parts of polyvinyl pyrrolidone, 0.3-0.6 parts of polyvinyl alcohol and 0.5-1.2 parts of nonylphenol polyoxyethylene ether by weight, and stir at a temperature of 40-60°C and a speed of 400-600 r / min for 50-80 min to obtain a mixed solution B; S3: Mix 0.6-0.9 parts of triammonium citrate, 0.2-0.5 parts of sodium succinate sulfonate and 0.1-0.3 parts of castor oil polyoxyethylene ether by weight, and stir at a temperature of 80-110° C. and a speed of 500-800 r / min for 40-70 min to obtain a mixed solution C; S4: Take the mixed solution A described in step S1, the mixed solution B described in step S2 and the mixed solution C described in step S3, and perform ultrasonic treatment at a temperature of 35-55° C. and a power of 1500-2500 W for 25-45 minutes to obtain an environmentally friendly pulse plating solution.

5. The method for preparing an environmentally friendly pulse plating solution according to claim 4, characterized in that: Step S1 is specifically as follows: by weight, 73 parts of copper sulfate pentahydrate, 110 parts of concentrated sulfuric acid with a mass fraction of 98% and 0.6 parts of sodium chloride are mixed, and stirred at a temperature of 65° C. and a speed of 350 r / min for 45 minutes to obtain a mixed solution A.

6. The method for preparing an environmentally friendly pulse plating solution according to claim 4, characterized in that: Step S2 is specifically as follows: 0.7-0.9 parts of polyvinyl pyrrolidone, 0.4-0.6 parts of polyvinyl alcohol and 0.5-1.0 parts of nonylphenol polyoxyethylene ether are mixed, and stirred at a temperature of 45-60° C. and a speed of 400-500 r / min for 60-70 minutes to obtain a mixed solution B.

7. The method for preparing an environmentally friendly pulse plating solution according to claim 4, characterized in that: Step S2 specifically comprises: mixing 0.7 parts of polyvinyl pyrrolidone, 0.5 parts of polyvinyl alcohol and 0.8 parts of nonylphenol polyoxyethylene ether, stirring at a temperature of 55° C. and a speed of 450 r / min for 65 minutes to obtain a mixed solution B.

8. The method for preparing an environmentally friendly pulse plating solution according to claim 7, characterized in that: 0.8 parts of triammonium citrate, 0.4 parts of sodium succinate sulfonate and 0.2 parts of castor oil polyoxyethylene ether were mixed, and stirred at 100°C and 650 r / min for 55 minutes to obtain a mixed solution C.

9. The method for preparing an environmentally friendly pulse plating solution according to claim 4, characterized in that: Step S4 is specifically as follows: taking the mixed solution A described in step S1, the mixed solution B described in step S2 and the mixed solution C described in step S3, ultrasonically treating them at a temperature of 40-50° C. and a power of 1800-2200 W for 30-40 minutes to obtain an environmentally friendly pulse plating solution.

10. The method for preparing an environmentally friendly pulse plating solution according to claim 9, characterized in that: The mixed solution A in step S1, the mixed solution B in step S2 and the mixed solution C in step S3 were ultrasonically treated at a temperature of 42° C. and a power of 2000 W for 35 min to obtain an environmentally friendly pulse plating solution.

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