High-density punched tin-plated copper strip electroplating solution and processing method

Abstract

The application relates to the technical field of metal tinning, and discloses a high-density punched tinned copper strip electroplating solution and a processing method. The electroplating solution comprises methylsulfonic acid, tin methylsulfonate, 180 additive and 180 auxiliary agent. The processing method comprises the steps of punching, negative-positive grade cross electrolysis degreasing, surface activation, tinning and water washing and drying. The 180 auxiliary agent is used to replace the traditional anti-oxidant, chromium-containing passivation or cyanide in the electroplating solution, so that the electroplating solution is more environmentally-friendly and safe. The electroplating solution is always in a dynamic balance process during the tinning system operation process by matching the methylsulfonic acid and the tin methylsulfonate with a higher content. The anode tin is rapidly transferred to the punched copper strip of the negative grade, a 1.5-3.0-micron uniform tinning layer is formed on the surface of the punched copper strip, the tinning layer and the substrate are well combined, the tinning layer is fine and detailed, has no pinhole and pimple, is not oxidized and has no blackening.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal tinning, in particular to a high-density punched tinned copper strip electroplating solution and processing method. BACKGROUND

[0002] Punched tinned copper strip is an ideal carrier for the negative active material of nickel-zinc batteries. Due to the advantages of nickel-zinc batteries, such as (1) high working voltage, reaching 1.65 volts; (2) excellent specific energy; (3) excellent discharge power; (4) significant environmental protection characteristics, ensuring intrinsic safety and no pollution; (5) relatively low cost, providing excellent cost performance, etc., nickel-zinc batteries are widely used in green transportation tools, power tools and electrochemical energy storage fields.

[0003] In the production process of punched tinned copper strip, a layer of metal tin is electroplated on the surface of the copper strip, which not only effectively prevents the oxidation and corrosion of copper, but also significantly improves the winding performance and welding performance of the pole piece, thereby better adapting to the large-current discharge requirements of nickel-zinc batteries.

[0004] However, during the process of electroplating tin on the surface of the copper strip, some challenges may be encountered, such as impurity ion replacement, cathode hydrogen evolution and other side reactions. The occurrence of these side reactions will cause defects such as blackening, pinholes, pitting and porosity on the surface of the plating layer, resulting in reduced density and corrosion resistance of the plating layer, which seriously affects the quality and performance of the product. Therefore, antioxidants, chromium-containing passivation substances or cyanide substances are often added to the commonly used tinning electroplating solution formula, which causes the above-mentioned components to be consumed with the product being taken out after a period of production, resulting in a decrease in the proportion of functional components in the electroplating solution, and thus causing a series of problems such as the appearance of surface defects, low thickness and decreased density of the plating layer, ultimately leading to a decrease in the overall quality of the product. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a high-density punched tinned copper strip electroplating solution with no defects such as blackening, pinholes, pitting and porosity on the surface of the plating layer, strong plating layer adhesion and good corrosion resistance, and a processing method thereof.

[0006] To solve the above technical problems, the present application provides a high-density punched tinned copper strip electroplating solution, which comprises:

[0007] 100mL / L-180mL / L of methylsulfonic acid, 100mL / L-170mL / L of tin methylsulfonate, 20mL / L-40mL / L of 180 additive, and 20mL / L-40mL / L of 180 auxiliary agent;

[0008] The 180 additive is composed of 25.0%-35.0% methanol, 1.0%-5.0% 2-methyl-2-propenoic acid, 0.1%-1.0% 4-phenyl-3-buten-2-one, and the rest is water;

[0009] The 180 auxiliary agent is composed of 10.0%-20.0% polyalkylene glycol and 80%-90% water.

[0010] As a preferred embodiment of the present application, the high-density punched tin-plated copper strip electroplating solution comprises:

[0011] Methyl sulfonic acid 120 mL / L-160 mL / L, tin methyl sulfonate 125 mL / L-145 mL / L, 180 additive 25 mL / L-35 mL / L, and 180 auxiliary agent 25 mL / L-35 mL / L.

[0012] As a preferred embodiment of the present application, the high-density punched tin-plated copper strip electroplating solution comprises:

[0013] Methyl sulfonic acid 140 mL / L, tin methyl sulfonate 135 mL / L, 180 additive 30 mL / L, and 180 auxiliary agent 30 mL / L.

[0014] The present application also provides a processing method for high-density punched tin-plated copper strip, which uses any one of the above high-density punched tin-plated copper strip electroplating solutions, and the steps are as follows:

[0015] S1, punching: punching the copper strip using a high-speed punch;

[0016] S2, oil removal: performing negative-positive level cross electrolytic oil removal on the punched copper strip in the oil removal liquid to remove surface stains and deposits of the punched copper strip and discharge hydrogen infiltrated into the metal;

[0017] S3, surface activation: first washing the punched copper strip after oil removal with deionized water, and then performing surface activation using a methyl sulfonic acid liquid after the first washing;

[0018] S4, tin plating: second washing the punched copper strip after surface activation with deionized water, and then quickly entering a total length of 8 m of electroplating tank for tin plating, the electroplating solution in the electroplating tank is the above high-density punched tin-plated copper strip electroplating solution, the electroplating temperature is 5°C-30°C, the pure metal tin ball is used as the anode and the punched copper strip is used as the cathode during electroplating, the moving speed of the punched copper strip is 5 m / min-20 m / min, the current distribution is 2 Ah / dm 2 -4 Ah / dm 2 , and the control voltage is 4 V-10 V.

[0019] S5, water washing and drying: after the electroplating, the punched copper belt is washed with water for the third time, and then dried to obtain a high-density punched tin-plated copper belt.

[0020] As some embodiments of the present application, the thickness of the copper belt in step S1 is 0.1 mm, and the surface is required to be flat after punching.

[0021] As some embodiments of the present application, in step S2, the oil removal liquid is a sodium hydroxide solution with a concentration of 50 g / L to 90 g / L, the oil removal temperature is 40°C to 70°C, and the oil removal current is 70 A to 90 A.

[0022] As some embodiments of the present application, in step S3, a 5% to 10% methanesulfonic acid liquid is used for surface activation.

[0023] As some embodiments of the present application, in step S4, the electroplating temperature is 10°C to 25°C, the moving speed of the punched copper belt is 8 m / min to 15 m / min, the current distribution is 3 Ah / dm 2 , and the voltage is 5V to 7V.

[0024] As a preferred embodiment of the present application, in step S4, the electroplating temperature is 15°C, the moving speed of the punched copper belt is 10 m / min, and the voltage is 6V.

[0025] As some embodiments of the present application, in step S5, the oven temperature is set to 150°C during drying.

[0026] Compared with the prior art, the present application has the following advantages:

[0027] In the electroplating solution of the present application, polyalkylene glycol is used to replace the antioxidants, chromium-containing passivates or cyanides in the traditional electroplating solution, making the electroplating solution more environmentally friendly and safe. In addition, a small amount of methanol and a high content of methanesulfonic acid and tin methanesulfonate are added, so that during the electroplating process, methanesulfonic acid continuously generates tin methanesulfonate at the positive electrode of the pure tin ball, and the tin methanesulfonate in the solution continuously deposits tin on the surface of the negative punched copper belt to generate new methanesulfonic acid, so that the tin plating system is in a dynamic balance process. The initial configuration of the electroplating solution with a certain concentration of tin methanesulfonate provides sufficient tin elements for the electroplating of the punched copper belt surface in the initial stage. Because polyalkylene glycol and methanol do not participate in the electroplating reaction process and do not accumulate near the negative punched copper belt, the electroplating solution will be consumed with the product, but the total amount of the electroplating solution will be reduced, and the content of each component will remain basically unchanged, so that the tin plating process is continuous and stable. By rapidly transferring the anode tin to the cathode punched copper belt, a uniform tin plating layer of 1.5 μm to 3.0 μm is formed on the surface of the punched copper belt, and the plating layer and the substrate are well combined, the plating layer is fine and has no pinholes, and the plating layer is not oxidized and blackened.

[0028] In the processing of high-density punched tin-plated copper strip, the temperature in the electroplating process is controlled at about 15℃, which on the one hand ensures the normal and stable operation of electroplating, and on the other hand avoids the volatilization of substances in the electroplating solution, ensuring the balance of the content of substances in the electroplating solution. The electrolytic cathode and anode cross-over oil removal method is adopted, the cathode is used to remove the stains on the surface of the punched copper strip, and then the cathode is changed to anode, the hydrogen penetrated into the metal is removed in a short time, and the deposition on the surface of the punched copper strip is also dissolved, so that a clean surface is obtained. Then the punched copper strip is surface activated, so that the tin is more easily attached to the surface during electroplating, the adhesion between the plating layer and the substrate is enhanced, the flatness of the plating layer is improved, and then the plating layer is dense. After surface activation, the punched copper strip is quickly put into the electroplating tank to avoid contamination of the activated surface by other substances, and to avoid deactivation of the activated surface. DETAILED DESCRIPTION

[0029] In order to make the technical means, creative features, purposes and effects realized by the present application easy to understand, the technical solutions in the specific embodiments of the present application will be described clearly and completely below to further illustrate the present application. Obviously, the described specific embodiments are only a part of the embodiments of the present application, not all.

[0030] It should be noted that: in the process of tin plating of punched copper strip, the thickness of the punched copper strip has little effect on the implementation of the tin plating process, so only 1mm thick punched copper strip is used as the substrate for experiment in the embodiment of the present application. It should be understood that the electroplating solution and processing method of the present application also has the same or similar effect on copper strips of other thicknesses. The purpose of punching the copper strip with a special die and a specific punching speed in step S1 of the embodiment of the present application is to meet the requirements of the hole rate and active material filling amount of the subsequent product used in nickel-zinc batteries. It does not affect the final effect and performance of the tin plating process. It should be understood that the present application has the same or similar effect on products such as non-porous copper strip, punched copper strip and perforated copper strip.

[0031] Embodiment 1: In this embodiment, the composition of the high-density punched tin-plated copper strip electroplating solution is:

[0032] Methyl sulfonic acid 140mL / L, tin methyl sulfonate 135mL / L, 180 additive 30mL / L, 180 auxiliary agent 30mL / L;

[0033] The 180 additive is VALTEK 180 additive produced by Rongmei Electronic Materials (Dongguan) Co., Ltd., with SDS number 10106871, and its specific composition is: 25.0%-35.0% methanol (CASRN: 67-56-1), 1.0%-5.0% 2-methyl-2-propenoic acid (CASRN: 79-41-4), 0.1%-<1.0% 4-phenyl-3-buten-2-one (CASRN: 122-57-6), and the balance is water (CASRN: 7732-18-5);

[0034] The 180 additive is VALTEK 180 additive produced by Rongmei Electronic Materials (Dongguan) Co., Ltd., with SDS number 10106871, and its specific composition is: 25.0%-35.0% methanol (CASRN: 67-56-1), 1.0%-5.0% 2-methyl-2-propenoic acid (CASRN: 79-41-4), 0.1%-<1.0% 4-phenyl-3-buten-2-one (CASRN: 122-57-6), and the balance is water (CASRN: 7732-18-5);

[0035] The specific processing method and process parameters in this embodiment are as follows:

[0036] S1, punching: using a special die to punch the copper plate with a thickness of 0.1 mm by using a high-speed punch, using a specific punching speed to make the surface of the punched copper strip smooth, increase the opening rate, and facilitate subsequent processing to improve the filling amount of active substances;

[0037] S2, oil removal: using a sodium hydroxide solution with a concentration of 60 g / L as an oil removal liquid, performing positive and negative level cross electrolysis oil removal on the punched copper strip, the oil removal temperature is 55°C, the oil removal current is 80A, and the surface stains and deposits of the punched copper strip are removed, and the hydrogen infiltrated into the metal is discharged;

[0038] S3, surface activation: first washing the punched copper strip after oil removal with deionized water, and then using 7% methanesulfonic acid liquid for surface activation;

[0039] S4, tin plating: first washing the punched copper strip after surface activation with deionized water, and then quickly entering an electroplating bath with a total length of 8 m for tin plating, the electroplating bath composition is as described above, the electroplating temperature is 15°C, the pure metal tin ball is used as the anode, the punched copper strip is used as the cathode, the moving speed of the punched copper strip is 10 m / min, the current distribution is 3 Ah / dm 2 , and the control voltage is 6V;

[0040] S5, water washing and drying: after electroplating, the punched copper strip is washed with water for the third time, and then dried in an oven with a temperature setting of 150°C, thereby obtaining a high-density punched tin-plated copper strip.

[0041] The high-density punched tin-plated copper strip obtained in this embodiment is sampled for coating detection and gas evolution amount test analysis, and the results are shown in Table 1.

[0042] In this embodiment, the process is consistent with that of Embodiment 1, except that the composition of the electrolyte is different. In this embodiment, the composition of the high-density punched tin-plated copper strip plating solution is as follows:

[0043] Methyl sulfonic acid 100 mL / L, tin methyl sulfonate 170 mL / L, 180 additive 20 mL / L, 180 auxiliary agent 40 mL / L;

[0044] Among them, the 180 additive is VALTEK 180 additive produced by Rongmei Electronic Materials (Dongguan) Co., Ltd., with SDS number 10106871. Its specific composition is: 25.0%-35.0% methanol, 1.0%-5.0% 2-methyl-2-propenoic acid, 0.1%-<1.0% 4-phenyl-3-buten-2-ketone, and the balance is water;

[0045] The 180 auxiliary agent is VALTEK 180 auxiliary agent produced by Rongmei Electronic Materials (Dongguan) Co., Ltd. Its specific composition is: 10.0%-20.0% polyalkylene glycol, 80%-90% water.

[0046] In this embodiment, the specific processing method and process parameters are as follows:

[0047] S1, punching: using a special die to punch the copper plate with a thickness of 0.1 mm by a high-speed punch, using a specific punching speed to make the surface of the punched copper strip smooth, increase the opening rate, and facilitate subsequent processing to improve the filling amount of active substances;

[0048] S2, oil removal: using a sodium hydroxide solution with a concentration of 60 g / L as the oil removal liquid, the punched copper strip is subjected to positive and negative level cross electrolysis for oil removal, the oil removal temperature is 55°C, the oil removal current is 80A, and the surface stains and deposits of the punched copper strip are removed, and the hydrogen infiltrated into the metal is discharged;

[0049] S3, surface activation: the punched copper strip after oil removal is first washed with deionized water for the first time, and then the surface is activated with 7% methyl sulfonic acid liquid;

[0050] S4, tin plating: the punched copper strip after surface activation is first washed with deionized water for the second time, and then quickly enters the total length of 8 m of the electroplating tank for tin plating. The composition of the electroplating solution in the electroplating tank is as described above, the electroplating temperature is 15°C, the pure metal tin ball is used as the anode during electroplating, the punched copper strip is used as the cathode, the moving speed of the punched copper strip is 10 m / min, the current distribution is 3 Ah / dm 2 , and the control voltage is 6V;

[0051] S5, washing and drying: after the electroplating, the punched copper belt is washed for the third time, and then dried in an oven with a temperature setting of 150 DEG C, so as to obtain the high-density punched tin-plated copper belt.

[0052] The high-density punched tin-plated copper belt obtained in the embodiment is sampled for coating detection and gas evolution amount test analysis, and the results are shown in Table 1.

[0053] In the embodiment, the process is consistent with that of Example 1, and the difference is the composition of the electrolyte. The composition of the high-density punched tin-plated copper belt electroplating solution is as follows:

[0054] Methyl sulfonic acid 180 mL / L, tin methyl sulfonate 100 mL / L, 180 additive 40 mL / L, 180 auxiliary agent 20 mL / L;

[0055] The 180 additive is VALTEK 180 additive produced by Rohm and Haas Electronic Materials (Dongguan) Co., Ltd., with SDS number 10106871, and the specific composition is: 25.0% to 35.0% methanol, 1.0% to 5.0% 2-methyl-2-propenoic acid, 0.1% to <1.0% 4-phenyl-3-buten-2-one, and the balance is water.

[0056] The 180 auxiliary agent is VALTEK 180 auxiliary agent produced by Rohm and Haas Electronic Materials (Dongguan) Co., Ltd., and the specific composition is: 10.0% to 20.0% polyalkylene glycol, 80% to 90% water.

[0057] The specific processing method and process parameters in the embodiment are as follows:

[0058] S1, punching: using a special die to punch the 0.1 mm thick copper plate with a high-speed punch, using a specific punching speed to make the surface of the punched copper belt smooth, increase the opening rate, and facilitate subsequent processing to increase the filling amount of active substances;

[0059] S2, oil removal: using a sodium hydroxide solution with a concentration of 70 g / L as an oil removal liquid, the punched copper belt is subjected to positive and negative level cross electrolysis oil removal, the oil removal temperature is 55 DEG C, the oil removal current is 80 A, and the hydrogen in the metal is removed.

[0060] S3, surface activation: the punched copper belt after oil removal is washed with deionized water for the first time, and then 7% methyl sulfonic acid liquid is used for surface activation.

[0061] S4, tin plating: after the second water washing, the punched copper strip after surface activation is quickly put into the electroplating bath with a total length of 8 m for tin plating, the composition of the electroplating bath in the electroplating bath is as above, the electroplating temperature is 15℃, the pure metal tin ball is used as the anode during electroplating, the punched copper strip is used as the cathode, the moving speed of the punched copper strip is 10 m / min, the current distribution is 3 Ah / dm 2 , and the control voltage is 6V;

[0062] S5, water washing and drying: after the electroplating, the punched copper strip is subjected to the third water washing, and then is dried in the oven with a temperature setting of 150℃, thereby obtaining the high-density punched tin-plated copper strip.

[0063] The high-density punched tin-plated copper strip obtained in the embodiment is sampled for coating detection and gas evolution amount test analysis, and the results are shown in Table 1.

[0064] In the embodiment, the composition and content of the electroplating bath are the same as those in Embodiment 1, and the difference is the parameter of the electroplating process, and the composition of the high-density punched tin-plated copper strip electroplating bath is:

[0065] Methyl sulfonic acid 140 mL / L, tin methyl sulfonate 135 mL / L, 180 additive 30 mL / L, 180 auxiliary agent 30 mL / L;

[0066] Among them, the 180 additive is VALTEK 180 additive with SDS number 10106871 produced by Rongmeihas Electronic Materials (Dongguan) Co., Ltd., and the specific composition is: 25.0%-35.0% of methanol, 1.0%-5.0% of 2-methyl-2-propenoic acid, 0.1%-<1.0% of 4-phenyl-3-buten-2-ketone, and the balance is water;

[0067] The 180 auxiliary agent is VALTEK 180 auxiliary agent produced by Rongmeihas Electronic Materials (Dongguan) Co., Ltd., and the specific composition is: 10.0%-20.0% of polyalkylene glycol, 80%-90% of water.

[0068] In the embodiment, the specific processing method and process parameters are as follows:

[0069] S1, punching: using a high-speed punch to punch the copper plate with a thickness of 0.1 mm using a special die, using a specific punching speed to make the surface of the punched copper strip smooth, increasing the opening rate, and facilitating subsequent processing to increase the filling amount of active substances;

[0070] S2, oil removal: using a sodium hydroxide solution with a concentration of 70 g / L as an oil removal liquid, the punched copper strip is subjected to cross electrolysis oil removal, the oil removal temperature is 55℃, the oil removal current is 80A, and the surface stains and deposits of the punched copper strip are removed, and the hydrogen permeated into the metal is discharged;

[0071] S3, surface activation: the punched copper strip after oil removal is first washed with deionized water for the first time, and then surface activation is carried out using 7% methyl sulfonic acid liquid after the first water washing;

[0072] S4, tin plating: the punched copper strip after surface activation is washed with deionized water for the second time, and then quickly enters the electroplating bath with a total length of 8 m for tin plating. The composition of the electroplating bath is as described above, the electroplating temperature is 5°C, the pure metal tin ball is used as the anode during electroplating, the punched copper strip is used as the cathode, the moving speed of the punched copper strip is 5 m / min, the current distribution is 2 Ah / dm 2 , and the control voltage is 4V;

[0073] S5, water washing and drying: after electroplating, the punched copper strip is washed with water for the third time, and then dried in an oven with a temperature setting of 150°C, thereby obtaining a high-density punched tin-plated copper strip.

[0074] The high-density punched tin-plated copper strip obtained in this embodiment is sampled for coating detection and gas evolution amount test analysis, and the results are shown in Table 1.

[0075] Example 5: In this embodiment, the composition and content of the electroplating bath are the same as those in Example 1, and the difference is the parameter of the electroplating process. The composition of the high-density punched tin-plated copper strip electroplating bath is:

[0076] Methyl sulfonic acid 140 mL / L, tin methyl sulfonic acid 135 mL / L, 180 additive 30 mL / L, 180 auxiliary agent 30 mL / L;

[0077] Among them, the 180 additive is VALTEK 180 additive produced by Romenhas Electronic Materials (Dongguan) Co., Ltd. with SDS number 10106871, and its specific composition is: 25.0%-35.0% methanol, 1.0%-5.0% 2-methyl-2-propenoic acid, 0.1%-<1.0% 4-phenyl-3-buten-2-ketone, and the balance is water;

[0078] The 180 auxiliary agent is VALTEK 180 auxiliary agent produced by Romenhas Electronic Materials (Dongguan) Co., Ltd., and its specific composition is: 10.0%-20.0% polyalkylene glycol, 80%-90% water.

[0079] The specific processing method and process parameters in this embodiment are as follows:

[0080] S1, punching: using a high-speed punch to punch a copper plate with a thickness of 0.1 mm using a special die, using a specific punching speed to make the surface of the punched copper strip smooth, increase the opening rate, and facilitate subsequent processing to increase the filling amount of active substances;

[0081] S2, oil removal: the punched copper strip is subjected to cross electrolysis oil removal with sodium hydroxide solution with a concentration of 70 g / L as the oil removal liquid, the oil removal temperature is 55°C, the oil removal current is 80 A, and the surface stains and deposits of the punched copper strip and the hydrogen infiltrated into the metal are removed;

[0082] S3, surface activation: the punched copper strip after oil removal is subjected to first water washing with deionized water, and then surface activation is performed with 7% methanesulfonic acid liquid;

[0083] S4, tin plating: the punched copper strip after surface activation is subjected to second water washing with deionized water, and then is rapidly introduced into an electroplating bath with a total length of 8 m for tin plating, the electroplating bath is composed of the above-mentioned components, the electroplating temperature is 30°C, a pure metal tin ball is used as the anode, the punched copper strip is used as the cathode, the moving speed of the punched copper strip is 20 m / min, the current distribution is 4 Ah / dm 2 , and the control voltage is 10 V;

[0084] S5, water washing and drying: after electroplating, the punched copper strip is subjected to third water washing, and then is dried in an oven with a temperature setting of 150°C, thereby obtaining the high-density punched tin-plated copper strip.

[0085] The high-density punched tin-plated copper strip obtained in the embodiment is sampled for plating layer detection and gas evolution amount test analysis, and the results are shown in Table 1.

[0086] Comparative Example 1: the conventional tin plating electroplating bath formula used in the comparative example is as follows: stannous sulfate 40 g / L-60 g / L; sulfuric acid 40 g / L-60 g / L; sodium phenolsulfonate 30 g / L-40 g / L; additive 1 g / L-2 g / L. The product is subjected to tin plating under normal process conditions, and the product is sampled for plating layer detection and gas evolution amount test analysis, and the test results are shown in Table 1.

[0087] Comparative Example 2: the comparative example is basically the same as Comparative Example 1, except that the electroplating bath is continuously supplemented and purified during electroplating, and the product is sampled for plating layer detection and gas evolution amount test analysis, and the test results are shown in Table 1.

[0088] In the present application, the test principle of gas evolution amount is as follows: zinc and tin layer surface impurities (mainly iron and nickel) form micro-batteries in 30% KOH electrolyte in a glass bottle, when the tin plating layer has poor compactness and has many surface gaps, the metal impurities doped in the plating layer will react with zinc electrochemically, and gas is generated on the electrode surface. In a sealed environment, the gas thrust pushes the paraffin oil into the plastic tube of the syringe, and the amount of exuded paraffin oil can be used to calculate the metal impurities so as to evaluate the quality of the plating layer.

[0089] The gas evolution amount test method is as follows: the sample is cut into a 15 cm*3 cm sheet along the length direction, washed with deionized water and dried, the sample is placed in a dried tray, placed in a constant temperature oven at 200 DEG C for 45 min, the tray is taken out and cooled at room temperature.

[0090] The cooled sample sheet is placed in a 30 mL glass bottle, 5 g of zinc powder is added and evenly distributed at the bottom of the bottle, 20 mL of 30% potassium hydroxide solution is added, the remaining space in the glass bottle is filled with paraffin oil after the addition, the rubber cap is tightly closed, then the aluminum cap is placed on the rubber cap and sealed with a seal.

[0091] The inner plastic core of a disposable syringe is pulled out, the needle is screwed tightly, then the syringe is inserted into the rubber cap (the needle is required to be fully inserted), the AB glue is applied to the joint between the needle and the cap, the joint between the cap and the glass bottle and the joint between the plastic cap and the aluminum cap. Start timing, record the liquid level on the syringe every 24 h, record for 3 times continuously, and the average value of the 3-day readings is the gas evolution amount test data of the sample.

[0092] Table 1 Performance test table of punched tin-plated copper strip

[0093]

[0094] As shown in Table 1, the commonly used plating solution needs to be continuously supplemented with effective components and purified during the production process, otherwise the quality and performance of the product will be seriously affected. The plating layer of the method implemented by the present application is qualified, and the gas evolution amount test shows that the compactness of the plating layer of the product of the present application is significantly higher than that of the product of the traditional process, which indicates that the technical advantage of the present application is significant.

[0095] The above describes the main technical features and basic principles of the present application and related advantages, for those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the concept or basic features of the present application. Therefore, from any point of view, the above-mentioned specific embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application.

[0096] In addition, it should be understood that although the present specification is described according to each embodiment, not every embodiment contains only one independent technical solution, the description manner of the specification is only for the sake of clarity, those skilled in the art should consider the specification as a whole, the technical solutions in each embodiment can also be combined appropriately to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high-density electroplating solution for perforated tin-plated copper strips, characterized in that, include: Methanesulfonic acid 100mL / L~180mL / L, tin methanesulfonate 100mL / L~170mL / L, 180 additive 20mL / L~40mL / L, 180 auxiliary agent 20mL / L~40mL / L; The 180 additive consists of: 25.0%–35.0% methanol, 1.0%–5.0% 2-methyl-2-acrylic acid, 0.1%–<1.0% 4-phenyl-3-buten-2-one, and the balance being water; The 180 auxiliary agent consists of 10.0%–20.0% polyalkyl glycol and 80%–90% water.

2. The high-density perforated tin-plated copper strip electroplating solution according to claim 1, characterized in that, include: Methanesulfonic acid 120mL / L~160mL / L, tin methanesulfonate 125mL / L~145mL / L, 180 additive 25mL / L~35mL / L, 180 auxiliary agent 25mL / L~35mL / L.

3. The high-density perforated tin-plated copper strip electroplating solution according to claim 2, characterized in that, include: Methanesulfonic acid 140 mL / L, tin methanesulfonate 135 mL / L, 180 additive 30 mL / L, 180 auxiliary agent 30 mL / L.

4. A method for processing high-density punched tin-plated copper strip, characterized in that, The steps of this method are as follows: S1. Punching: Using a high-speed punch press to punch holes in copper strips; S2. Degreasing: The perforated copper strip is then subjected to cross-electrode degreasing in a degreasing liquid to remove stains and deposits on the surface of the perforated copper strip and to remove hydrogen that has penetrated into the metal. S3. Surface activation: First, use deionized water to wash the degreased punched copper strip for the first time. After the first water wash, use methanesulfonic acid liquid for surface activation. S4. Tin Plating: The perforated copper strip, after surface activation, is first rinsed a second time with deionized water. After the second rinse, it is quickly immersed in an 8m long electroplating tank for tin plating. The electroplating solution in the tank is the high-density perforated tin-plated copper strip electroplating solution as described in any one of claims 1-3. The electroplating temperature is 5℃~30℃. During electroplating, pure tin balls are used as the anode, and the perforated copper strip is used as the cathode. The moving speed of the perforated copper strip is 5m / min~20m / min, and the current distribution is 2Ah / dm. 2 ~4Ah / dm 2 The control voltage is 4V to 10V; S5. Washing and drying: After electroplating, the perforated copper strip is washed a third time and then dried to obtain a high-density perforated tin-plated copper strip.

5. The processing method for a high-density punched tin-plated copper strip according to claim 4, characterized in that, In step S1, the thickness of the copper strip is 0.1 mm, and the surface of the copper strip is flat after punching.

6. The processing method for a high-density punched tin-plated copper strip according to claim 4, characterized in that, In step S2, the degreasing liquid is a sodium hydroxide solution with a concentration of 30 g / L to 70 g / L, the degreasing temperature is 50℃ to 70℃, and the degreasing current is 70A to 90A.

7. The processing method for a high-density punched tin-plated copper strip according to claim 4, characterized in that, In step S3, surface activation is performed using 5% to 10% methanesulfonic acid liquid.

8. The processing method for a high-density punched tin-plated copper strip according to claim 4, characterized in that, In step S4, the electroplating temperature is 10℃~25℃, the moving speed of the punched copper strip is 8m / min~15m / min, and the current distribution is 3Ah / dm. 2 The voltage is 5V to 7V.

9. The processing method for a high-density punched tin-plated copper strip according to claim 8, characterized in that, In step S4, the electroplating temperature is 15℃, the moving speed of the punched copper strip is 10m / min, and the voltage is 6V.

10. The processing method for a high-density punched tin-plated copper strip according to claim 4, characterized in that, In step S5, the oven temperature is set to 150°C during drying.

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