阅读说明：本技术 用于铜线镀锡的电镀液及铜线电镀锡的方法 (Electroplating solution for tinning copper wire and method for electroplating tin on copper wire ) 是由 吴金朝 于 2021-08-13 设计创作，主要内容包括：本发明公开了一种用于铜线镀锡的电镀液,电镀液包括以下含量的原料：硫酸亚锡、硫酸、酚磺酸、苯甲酰丙酮、异丁烯酸、丙烯酰胺、烷基酚聚氧乙烯醚、明胶、β-萘酚、甲基磺酸钠或甲基磺酸钾、酒石酸、硫酸钴、钒盐、十二烷基硫酸钠和pH调节剂。铜线电镀锡的方法,包括以下步骤：(1)铜线预处理；(2)铜线镀锡；(3)软溶处理；(4)封闭处理。本发明铜线电镀锡的方法,采用特定的电镀液,并配合合理的工艺方法,制备得到的镀锡铜线,锡层厚度均匀,耐腐蚀性强,锡层与铜线的附着力大,不易脱落。(The invention discloses an electroplating solution for tinning a copper wire, which comprises the following raw materials in parts by weight: stannous sulfate, sulfuric acid, phenolsulfonic acid, benzoylacetone, methacrylic acid, acrylamide, alkylphenol ethoxylates, gelatin, beta-naphthol, sodium or potassium methylsulfonate, tartaric acid, cobalt sulfate, vanadium salt, sodium lauryl sulfate and a pH regulator. The method for electroplating tin on the copper wire comprises the following steps: (1) copper wire pretreatment; (2) tinning a copper wire; (3) carrying out soft dissolving treatment; (4) and (5) sealing treatment. According to the method for electroplating tin on the copper wire, the tin-plated copper wire prepared by adopting the specific electroplating solution and matching with a reasonable process method is uniform in tin layer thickness and strong in corrosion resistance, and the tin layer and the copper wire are large in adhesive force and not easy to fall off.)

1. The electroplating solution for tinning of the copper wire is characterized by comprising the following raw materials in parts by weight: stannous sulfate, sulfuric acid, phenolsulfonic acid, benzoylacetone, methacrylic acid, acrylamide, alkylphenol ethoxylates, gelatin, beta-naphthol, sodium or potassium methylsulfonate, tartaric acid, cobalt sulfate, vanadium salt, sodium lauryl sulfate and a pH regulator.

2. The electroplating bath according to claim 1, comprising the following raw materials per liter of electroplating bath: 30-40g of stannous sulfate, 80-100g of sulfuric acid, 30-50g of phenolsulfonic acid, 2-5g of benzoylacetone, 1-3g of methacrylic acid, 1-3g of acrylamide, 0.5-2.5g of alkylphenol ethoxylates, 3-7g of gelatin, 1-4g of beta-naphthol, 2-7g of sodium methyl sulfonate or potassium methyl sulfonate, 3-8g of tartaric acid, 0.1-1.5g of cobalt sulfate, 0.2-1.3g of vanadium salt, 1-3g of sodium dodecyl sulfate and a pH regulator, wherein the pH regulator regulates the pH value of the electroplating solution to be 3-4.

3. The electroplating bath according to claim 1, comprising the following raw materials per liter of electroplating bath: 36g of stannous sulfate, 95g of sulfuric acid, 38g of phenol sulfonic acid, 3g of benzoylacetone, 2g of methacrylic acid, 2g of acrylamide, 1.5g of alkylphenol ethoxylates, 4g of gelatin, 3g of beta-naphthol, 4g of sodium methyl sulfonate or potassium methyl sulfonate, 5g of tartaric acid, 1.2g of cobalt sulfate, 0.8g of vanadium salt, 1.5g of sodium dodecyl sulfate and a pH regulator, wherein the pH regulator regulates the pH value of the electroplating solution to be 3.5.

4. The electroplating bath as recited in claim 1 wherein the pH adjuster is sodium hydroxide or potassium hydroxide.

5. A method for electroplating tin on a copper wire, characterized in that the electroplating is carried out by using the electroplating solution as claimed in any one of claims 1 to 4, and comprises the following steps:

(1) copper wire pretreatment: carrying out alkali washing, water washing and acid washing on a copper wire, wherein the copper wire is a copper-clad aluminum wire;

(2) tinning a copper wire: after being prepared, the electroplating solution is placed into a tinning bath, and the pretreated copper wire is introduced into the tinning bath for electroplating, wherein a tin plate is fixed in the tinning bath and is connected with the positive pole of a power supply, and the copper wire is connected with the negative pole of the power supply through a cathode roller; the electroplating process parameter is current density of 1-3A/dm²The temperature is 15-25 ℃, and the conveying speed of the copper conductor is 15-25 m/min;

(3) carrying out soft dissolving treatment: introducing the electroplated copper wire into a heating device at the temperature of 235-245 ℃, and then pressing by a roller;

(4) and (3) sealing, namely sealing the copper wire subjected to the soft dissolving treatment at 35-45 ℃ for 3-8 min.

6. The method for electroplating tin on the copper wire according to claim 5, wherein the copper wire is pretreated in the step (1) by soaking the copper wire in an alkaline solution of an alkaline washing tank for alkaline washing for a period of time, then moving the copper wire to a water washing tank for water washing, washing the copper wire with water, then placing the copper wire in the acid washing tank for degreasing treatment, and then moving the copper wire to the water washing tank for water washing.

7. The method for electrolytic tinning of copper wire according to claim 5, characterized in that the time of the soft-dissolving treatment in step (3) is 10 to 30 seconds.

8. The method for electroplating tin on a copper wire according to claim 5, wherein the sealing solution for the sealing treatment in the step (4) comprises the following raw materials per liter: 5-15g of ammonium fluotitanate, 2-8g of sodium metavanadate, 0.5-5g of triethanolamine, 1-3g of nitric acid, 0.5-2g of sodium dodecyl sulfate, 2-5g of sodium citrate, 0.5-2g of ethylenediamine tetraacetic acid, 3-9g of potassium permanganate and a pH value regulator, wherein the pH value regulator regulates the pH value of the sealing liquid to 5-6.

9. The method for electrolytic tinning of copper wire according to claim 5, characterized in that the sealing treatment is carried out under ultrasonic vibration conditions.

10. A tinned copper wire, characterized in that it is produced using the method according to any one of claims 5 to 9, and comprises, in order from the inside out, an aluminium core layer, a copper layer located outside the aluminium core layer, and a tin layer located outside the copper layer.

Technical Field

The invention relates to the technical field of electroplating, in particular to electroplating solution for tinning a copper wire and a method for electroplating tinning the copper wire.

Background

Tinned copper wire is copper wire with a thin layer of metallic tin plated on the surface of the copper wire. The tinned copper wire is soft in material and good in conductivity, and compared with a bare copper wire, the tinned copper wire is higher in corrosion resistance and oxidation resistance, and the service life of a weak current cable can be greatly prolonged.

The conductivity of copper is 100%, while that of tin is only 14%, so that the conductivity of the copper wire with tin attached to the same section of wire is lower than that of the bare copper wire, generally 93-94%, which is a defect theoretically, although the use of the copper wire is not affected, therefore, the tin protective layer is required to have a proper and uniform thickness and to be tightly connected with the copper. If tinned copper wires are produced, the insulating rubber can be prevented from being sticky, the wire cores can be prevented from being black and brittle, and the weldability can be improved.

The tin plating on the surface of the copper wire is generally divided into hot plating and cold plating. Hot tin plating, as the name implies, immerses a clean-surfaced metallic material or part in a molten tin bath (which melts solid tin by heating) at elevated temperature, and utilizes the physical reaction at the interface to enhance the process of forming a layer of metallic tin closely on the surface by pressing. Cold tin plating is also called electrolytic tin plating, and the process of adhering a layer of crystallized tin atoms on the surface of a base metal by utilizing the electrolysis principle needs positive and negative electrodes and a positive and negative electrode as power media, and is an electroplating solution, an electroplating reaction, an electrode and chemical reaction principle and an electrodeposition process of metal.

The tin layer obtained by the existing copper wire tinning method has poor adhesion with the copper wire, is easy to fall off, seriously influences the service life of the copper wire, and easily causes the tinning solution and the surface of the copper wire not to react uniformly due to oil stains, oxidation and unoxidized surface impurities on the surface of the copper wire, so that the tinning layer has uneven thickness and poor stability.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention aims to provide an electroplating solution for tinning a copper wire, so that the defects that the tinning on the copper wire is easy to fall off and the service life of the copper wire is influenced are overcome.

Another object of the present invention is to provide a method for electroplating copper wire with tin.

In order to achieve the purpose, the invention provides a plating solution for tinning a copper wire, which comprises the following raw materials in percentage by weight: stannous sulfate, sulfuric acid, phenolsulfonic acid, benzoylacetone, methacrylic acid, acrylamide, alkylphenol ethoxylates, gelatin, beta-naphthol, sodium or potassium methylsulfonate, tartaric acid, cobalt sulfate, vanadium salt, sodium lauryl sulfate and a pH regulator.

Preferably, in the above technical solution, each liter of the electroplating solution includes the following raw materials: 30-40g of stannous sulfate, 80-100g of sulfuric acid, 30-50g of phenolsulfonic acid, 2-5g of benzoylacetone, 1-3g of methacrylic acid, 1-3g of acrylamide, 0.5-2.5g of alkylphenol ethoxylates, 3-7g of gelatin, 1-4g of beta-naphthol, 2-7g of sodium methyl sulfonate or potassium methyl sulfonate, 3-8g of tartaric acid, 0.1-1.5g of cobalt sulfate, 0.2-1.3g of vanadium salt, 1-3g of sodium dodecyl sulfate and a pH regulator, wherein the pH regulator regulates the pH value of the electroplating solution to be 3-4.

Preferably, in the above technical solution, each liter of the electroplating solution includes the following raw materials: 36g of stannous sulfate, 95g of sulfuric acid, 38g of phenol sulfonic acid, 3g of benzoylacetone, 2g of methacrylic acid, 2g of acrylamide, 1.5g of alkylphenol ethoxylates, 4g of gelatin, 3g of beta-naphthol, 4g of sodium methyl sulfonate or potassium methyl sulfonate, 5g of tartaric acid, 1.2g of cobalt sulfate, 0.8g of vanadium salt, 1.5g of sodium dodecyl sulfate and a pH regulator, wherein the pH regulator regulates the pH value of the electroplating solution to be 3.5.

Preferably, in the above technical solution, the pH adjusting agent is sodium hydroxide or potassium hydroxide.

The method for electroplating tin on the copper wire by using the electroplating solution comprises the following steps:

(1) copper wire pretreatment: carrying out alkali washing, water washing and acid washing on a copper wire, wherein the copper wire is a copper-clad aluminum wire;

(2) tinning a copper wire: after being prepared, the electroplating solution is placed into a tinning bath, and the pretreated copper wire is introduced into the tinning bath for electroplating, wherein a tin plate is fixed in the tinning bath and is connected with the positive pole of a power supply, and the copper wire is connected with the negative pole of the power supply through a cathode roller; the electroplating process parameter is current density of 1-3A/dm²The temperature is 15-25 ℃, and the conveying speed of the copper conductor is 15-25 m/min;

(3) carrying out soft dissolving treatment: introducing the electroplated copper wire into a heating device at the temperature of 235-245 ℃, and then pressing by a roller;

(4) and (3) sealing, namely sealing the copper wire subjected to the soft dissolving treatment at 35-45 ℃ for 3-8 min.

Preferably, in the above technical scheme, the copper wire pretreatment in step (1) is to soak the copper wire in an alkaline solution of an alkaline washing tank for alkaline washing for a period of time, then move the copper wire to a washing tank for water washing, clean in water, place the copper wire in an acid washing tank for degreasing treatment, and then move the copper wire to a washing tank for water washing.

Preferably, in the above technical scheme, the time for the soft dissolving treatment in the step (3) is 10-30 s.

Preferably, in the above technical solution, each liter of the sealing liquid for the sealing treatment in step (4) includes the following raw materials: 5-15g of ammonium fluotitanate, 2-8g of sodium metavanadate, 0.5-5g of triethanolamine, 1-3g of nitric acid, 0.5-2g of sodium dodecyl sulfate, 2-5g of sodium citrate, 0.5-2g of ethylenediamine tetraacetic acid, 3-9g of potassium permanganate and a pH value regulator, wherein the pH value regulator regulates the pH value of the sealing liquid to 5-6.

Preferably, in the above technical solution, the sealing treatment is performed under ultrasonic vibration.

The utility model provides a tinned wire, tinned wire includes the aluminium sandwich layer in proper order from inside to outside, is located copper layer outside the aluminium sandwich layer, and be located tin layer outside the copper layer.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention relates to an electroplating liquid for tinning a copper wire, which is prepared by adding ammonium acrylate, alkylphenol ethoxylates, sodium or potassium methylsulfonate, cobalt sulfate, sodium dodecyl benzene sulfonate and the like into the electroplating liquid through the mutual synergistic effect of the raw materials. The surface of the copper wire is tinned, the obtained tin layer is uniformly electroplated, and the adhesive force of the plating layer and the copper wire matrix is obviously improved.

(2) The invention provides a method for electroplating tin on a copper wire, which is characterized in that a tin-plated copper wire prepared by adopting a specific tin plating solution and matching with a reasonable process is uniform in tin layer thickness and strong in corrosion resistance, and the tin layer has large adhesive force with the copper wire and is not easy to fall off.

(3) In the method, after the copper wire is electroplated, the copper wire is subjected to soft solution treatment to partially melt the surface of the tin-plated layer, and the surface of the copper wire is flat, smooth and compact by the roller. After the copper wire passes through the roller, the copper wire is subjected to sealing treatment, so that the corrosion resistance of the tin coating is improved, and the tin coating on the surface of the copper wire is uniform, compact in structure and free of holes.

Detailed Description

The following detailed description of the present invention will be given with reference to specific examples, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

Example 1

A method for electroplating tin on a copper wire comprises the following steps:

firstly, preparing electroplating solution

(1) The raw material proportion for preparing the electroplating solution is as follows: each liter of electroplating solution comprises the following raw materials in percentage by weight: 36g of stannous sulfate, 95g of sulfuric acid, 38g of phenolsulfonic acid, 3g of benzoylacetone, 2g of methacrylic acid, 2g of acrylamide, 1.5g of alkylphenol ethoxylates, 4g of gelatin, 3g of beta-naphthol, 4g of potassium methylsulfonate, 5g of tartaric acid, 1.2g of cobalt sulfate, 0.8g of vanadium salt, 1.5g of sodium dodecyl sulfate and a pH regulator, wherein the pH regulator is sodium hydroxide, the pH value of the electroplating solution is regulated to 3.5 by the sodium hydroxide, and the vanadium salt is sodium orthovanadate.

(2) The configuration method comprises the following steps: firstly, slowly pouring sulfuric acid and phenolsulfonic acid into water while stirring, wherein the volume of the water is larger than 1/2 of the volume of the prepared plating solution, then slowly adding stannous sulfate while stirring, and then adding benzoylacetone, methacrylic acid, acrylamide, alkylphenol ethoxylates, sodium or potassium methylsulfonate, tartaric acid, cobalt sulfate, vanadium salt, sodium dodecyl sulfate and a pH regulator, wherein the pH regulator is sodium hydroxide or potassium hydroxide. The gelatin is soaked in a proper amount of warm water to swell, then heated and dissolved, the beta-naphthol is added into 8 times of ethanol to be dissolved, and then the gelatin solution and the beta-naphthol solution are mixed and added into the plating solution under stirring. The prepared electroplating solution is placed in a tin plating tank, and can be formally produced through trial plating after being electrolyzed for 3 hours in the tin plating tank.

Second, tin plating of copper wire

(1) Copper wire pretreatment: and (2) carrying out electrotinning on the copper-clad aluminum wire, carrying out alkaline washing, water washing and acid washing on the copper-clad aluminum wire, soaking the copper-clad aluminum wire in alkaline washing liquid of an alkaline washing tank for alkaline washing for 30s, wherein the alkaline washing liquid is 40g/L sodium hydroxide solution. And then moving the steel pipe to a washing tank for washing, placing the steel pipe in a pickling tank for degreasing treatment for 30s after the steel pipe is washed, and moving the steel pipe to the washing tank for washing. The cleaning liquid in the pickling tank comprises 45g/L sulfuric acid, 21g/L polyoxyethylene octylphenol ether, 14g/L triethanolamine, 10g/L sodium chloride, 12g/L citric acid and 13g/L disodium ethylene diamine tetraacetate.

(2) Tinning a copper wire: introducing the pretreated copper wire into a tinning bath for electroplating, wherein a tin plate is fixed in the tinning bath and connected with the positive electrode of a power supply, and the copper wire is connected with the negative electrode of the power supply through a cathode roller; the electroplating process parameter is the current density 2A/dm²The temperature is 20 ℃, and the conveying speed of the copper conductor is 15 m/min;

(3) carrying out soft dissolving treatment: introducing the electroplated copper wire into a heating device, wherein the temperature is 240 ℃, the time of the soft dissolving treatment is 15s, and then pressing by a roller;

(4) sealing treatment: and (3) sealing the copper wire subjected to the soft dissolving treatment for 6min under the ultrasonic condition, wherein the working power of ultrasonic waves is 45KHz, and the temperature of the sealing treatment is 40 ℃. Sealing liquid for sealing treatment, wherein each liter of sealing liquid comprises the following raw materials: 13g of ammonium fluotitanate, 6g of sodium metavanadate, 2g of triethanolamine, 2g of nitric acid, 1g of sodium dodecyl sulfate, 3g of sodium citrate, 1g of ethylenediamine tetraacetic acid, 5g of potassium permanganate and a pH value regulator, wherein the pH value regulator is sodium hydroxide, and the pH value of the sealing liquid is regulated to 5.5 by the sodium hydroxide.

(5) Washing and drying: and introducing the copper wire subjected to the sealing treatment into a washing tank for washing, and then introducing the copper wire subjected to washing into an oven for drying. The diameter d of the copper wire is 1.2 mm.

Example 2

A method for electroplating tin on a copper wire comprises the following steps:

firstly, preparing electroplating solution

(1) The raw material proportion for preparing the electroplating solution is as follows: each liter of electroplating solution comprises the following raw materials in percentage by weight: the electroplating solution comprises 40g of stannous sulfate, 80g of sulfuric acid, 50g of phenolsulfonic acid, 5g of benzoylacetone, 3g of methacrylic acid, 1g of acrylamide, 2.5g of alkylphenol ethoxylates, 3g of gelatin, 1g of beta-naphthol, 2g of sodium methanesulfonate, 3g of tartaric acid, 1.5g of cobalt sulfate, 1.3g of vanadium salt, 1g of sodium dodecyl sulfate and a pH regulator, wherein the pH value of the electroplating solution is adjusted to 3 by sodium hydroxide, and the vanadium salt is sodium orthovanadate.

(2) The configuration method comprises the following steps: firstly, slowly pouring sulfuric acid and phenolsulfonic acid into water while stirring, wherein the volume of the water is larger than 1/3 of the volume of the prepared plating solution, then slowly adding stannous sulfate while stirring, and then adding benzoylacetone, methacrylic acid, acrylamide, alkylphenol ethoxylates, sodium or potassium methylsulfonate, tartaric acid, cobalt sulfate, vanadium salt, sodium dodecyl sulfate and a pH regulator, wherein the pH regulator is sodium hydroxide or potassium hydroxide. The gelatin is soaked in a proper amount of warm water to swell, then heated and dissolved, the beta-naphthol is added into 5 times of ethanol to be dissolved, and then the gelatin solution and the beta-naphthol solution are mixed and added into the plating solution under stirring. The prepared electroplating solution is placed in a tin plating tank, and can be formally produced through trial plating after being electrolyzed for 3 hours in the tin plating tank.

Second, tin plating of copper wire

(1) Copper wire pretreatment: and (2) carrying out electrotinning on the copper-clad aluminum wire, carrying out alkaline washing, water washing and acid washing on the copper-clad aluminum wire, soaking the copper-clad aluminum wire in alkaline washing liquid of an alkaline washing tank for alkaline washing for 30s, wherein the alkaline washing liquid is 40g/L sodium hydroxide solution. And then moving the steel pipe to a washing tank for washing, placing the steel pipe in a pickling tank for degreasing treatment for 30s after the steel pipe is washed, and moving the steel pipe to the washing tank for washing. The cleaning liquid in the pickling tank comprises 45g/L sulfuric acid, 21g/L polyoxyethylene octylphenol ether, 14g/L triethanolamine, 10g/L sodium chloride, 12g/L citric acid and 13g/L disodium ethylene diamine tetraacetate.

(2) Tinning a copper wire: introducing the pretreated copper wire into a tinning bath for electroplating, wherein a tin plate is fixed in the tinning bath and connected with the positive electrode of a power supply, and the copper wire is connected with the negative electrode of the power supply through a cathode roller; the electroplating process parameter is current density 3A/dm²The temperature is 15 ℃, and the conveying speed of the copper conductor is 25 m/min;

(3) carrying out soft dissolving treatment: introducing the electroplated copper wire into a heating device, wherein the temperature is 235 ℃, the time of soft dissolving treatment is 30s, and then pressing by a roller;

(4) sealing treatment: and (3) sealing the copper wire subjected to the soft dissolving treatment for 3min under the ultrasonic condition, wherein the working power of ultrasonic waves is 45KHz, and the temperature of the sealing treatment is 45 ℃. Sealing liquid for sealing treatment, wherein each liter of sealing liquid comprises the following raw materials: 5-15g of ammonium fluotitanate, 2-8g of sodium metavanadate, 0.5-5g of triethanolamine, 1-3g of nitric acid, 0.5-2g of sodium dodecyl sulfate, 2-5g of sodium citrate, 0.5-2g of ethylenediamine tetraacetic acid, 3-9g of potassium permanganate and a pH value regulator, wherein the pH value regulator is sodium hydroxide, and the pH value of the sealing liquid is regulated to 5.5 by the sodium hydroxide.

(5) Washing and drying: and introducing the copper wire subjected to the sealing treatment into a washing tank for washing, and then introducing the copper wire subjected to washing into an oven for drying. The diameter d of the copper wire is 1.2 mm.

Example 3

A method for electroplating tin on a copper wire comprises the following steps:

firstly, preparing electroplating solution

(1) The raw material proportion for preparing the electroplating solution is as follows: each liter of electroplating solution comprises the following raw materials in percentage by weight: 30g of stannous sulfate, 100g of sulfuric acid, 30g of phenolsulfonic acid, 2g of benzoylacetone, 1g of methacrylic acid, 3g of acrylamide, 0.5g of alkylphenol polyoxyethylene, 7g of gelatin, 4g of beta-naphthol, 7g of potassium methylsulfonate, 8g of tartaric acid, 0.1g of cobalt sulfate, 0.2g of vanadium salt, 3g of sodium dodecyl sulfate and a pH regulator, wherein the pH regulator regulates the pH value of the electroplating solution to be 4, and the vanadium salt is sodium orthovanadate.

(2) The configuration method comprises the following steps: firstly, slowly pouring sulfuric acid and phenolsulfonic acid into water while stirring, wherein the volume of the water is larger than 1/2 of the volume of the prepared plating solution, then slowly adding stannous sulfate while stirring, and then adding benzoylacetone, methacrylic acid, acrylamide, alkylphenol ethoxylates, sodium or potassium methylsulfonate, tartaric acid, cobalt sulfate, vanadium salt, sodium dodecyl sulfate and a pH regulator, wherein the pH regulator is sodium hydroxide or potassium hydroxide. The gelatin is soaked in a proper amount of warm water to swell, then heated and dissolved, the beta-naphthol is added into 10 times of ethanol to be dissolved, and then the gelatin solution and the beta-naphthol solution are mixed and added into the plating solution under stirring. The prepared electroplating solution is placed in a tin plating tank, and can be formally produced through trial plating after being electrolyzed for 3 hours in the tin plating tank.

Second, tin plating of copper wire

(1) Copper wire pretreatment: and (2) carrying out electrotinning on the copper-clad aluminum wire, carrying out alkaline washing, water washing and acid washing on the copper-clad aluminum wire, soaking the copper-clad aluminum wire in alkaline washing liquid of an alkaline washing tank for alkaline washing for 30s, wherein the alkaline washing liquid is 40g/L sodium hydroxide solution. And then moving the steel pipe to a washing tank for washing, placing the steel pipe in a pickling tank for degreasing treatment for 30s after the steel pipe is washed, and moving the steel pipe to the washing tank for washing. The cleaning liquid in the pickling tank comprises 45g/L sulfuric acid, 21g/L polyoxyethylene octylphenol ether, 14g/L triethanolamine, 10g/L sodium chloride, 12g/L citric acid and 13g/L disodium ethylene diamine tetraacetate.

(2) Tinning a copper wire: introducing the pretreated copper wire into a tinning bath for electroplating, wherein a tin plate is fixed in the tinning bath and connected with the positive electrode of a power supply, and the copper wire is connected with the negative electrode of the power supply through a cathode roller; the electroplating process parameter is current density 1A/dm²The temperature is 25 ℃, and the conveying speed of the copper conductor is 15 m/min;

(3) carrying out soft dissolving treatment: introducing the electroplated copper wire into a heating device, wherein the temperature is 245 ℃, the time of the soft dissolving treatment is 10s, and then pressing by a roller;

(4) sealing treatment: and (3) sealing the copper wire subjected to the soft dissolving treatment for 8min under the ultrasonic condition, wherein the working power of ultrasonic waves is 45KHz, and the temperature of the sealing treatment is 35 ℃. Sealing liquid for sealing treatment, wherein each liter of sealing liquid comprises the following raw materials: 15g of ammonium fluotitanate, 2g of sodium metavanadate, 0.5g of triethanolamine, 1g of nitric acid, 2g of sodium dodecyl sulfate, 2g of sodium citrate, 0.5g of ethylenediamine tetraacetic acid, 9g of potassium permanganate and a pH value regulator, wherein the pH value of the sealing liquid is regulated to 6 by the pH regulator.

(5) Washing and drying: and introducing the copper wire subjected to the sealing treatment into a washing tank for washing, and then introducing the copper wire subjected to washing into an oven for drying. The diameter d of the copper wire is 1.1 mm.

Example 4

The difference between the present embodiment and embodiment 1 lies in the raw material ratio of the electroplating solution, and each liter of the electroplating solution comprises the following raw materials: 33g of stannous sulfate, 88g of sulfuric acid, 43g of phenolsulfonic acid, 3.7g of benzoylacetone, 2.4g of methacrylic acid, 1.8g of acrylamide, 1.9g of alkylphenol ethoxylates, 5.3g of gelatin, 2.6g of beta-naphthol, 4.3g of sodium methanesulfonate, 4.5g of tartaric acid, 0.8g of cobalt sulfate, 0.8g of vanadium salt, 2.1g of sodium dodecyl sulfate and a pH regulator, wherein the pH regulator is sodium hydroxide, the pH value of the electroplating solution is regulated to 3.8 by the sodium hydroxide, and the vanadium salt is sodium orthovanadate. The diameter d of the copper wire is 1.2 mm.

Example 5

The difference between the present embodiment and embodiment 1 lies in the raw material ratio of the electroplating solution, and each liter of the electroplating solution comprises the following raw materials: each liter of electroplating solution comprises the following raw materials in percentage by weight: 32g of stannous sulfate, 98g of sulfuric acid, 43g of phenolsulfonic acid, 3.5g of benzoylacetone, 2.2g of methacrylic acid, 1.6g of acrylamide, 1.8g of alkylphenol ethoxylates, 4.9g of gelatin, 3.2g of beta-naphthol, 6.3g of sodium methanesulfonate, 5.4g of tartaric acid, 1.5g of cobalt sulfate, 0.7g of vanadium salt, 3g of sodium dodecyl sulfate and a pH regulator, wherein the pH regulator regulates the pH value of the electroplating solution to be 4, and the vanadium salt is sodium orthovanadate. The diameter d of the prepared copper wire is 1.0 mm.

Comparative example 1

This example differs from example 1 in that the method of electroplating copper wire with tin is different, and the step of electroplating copper wire with tin comprises the following steps:

(1) copper wire pretreatment: and (2) carrying out electrotinning on the copper-clad aluminum wire, carrying out alkaline washing, water washing and acid washing on the copper-clad aluminum wire, soaking the copper-clad aluminum wire in alkaline washing liquid of an alkaline washing tank for alkaline washing for 30s, wherein the alkaline washing liquid is 40g/L sodium hydroxide solution. And then moving the steel pipe to a washing tank for washing, placing the steel pipe in a pickling tank for degreasing treatment for 30s after the steel pipe is washed, and moving the steel pipe to the washing tank for washing. The cleaning liquid in the pickling tank comprises 45g/L sulfuric acid, 21g/L polyoxyethylene octylphenol ether, 14g/L triethanolamine, 10g/L sodium chloride, 12g/L citric acid and 13g/L disodium ethylene diamine tetraacetate.

(2) Tinning a copper wire: introducing the pretreated copper wire into a tinning bath for electroplating, wherein a tin plate is fixed in the tinning bathThe tin plate is connected with the positive pole of a power supply, and the copper wire is connected with the negative pole of the power supply through a cathode roller; the electroplating process parameter is the current density 2A/dm²The temperature is 20 ℃, and the conveying speed of the copper conductor is 15 m/min;

(3) sealing treatment: and (3) sealing the tinned copper wire for 6min under the ultrasonic condition, wherein the working power of ultrasonic waves is 45KHz, and the temperature of sealing treatment is 40 ℃. Sealing liquid for sealing treatment, wherein each liter of sealing liquid comprises the following raw materials: 13g of ammonium fluotitanate, 6g of sodium metavanadate, 2g of triethanolamine, 2g of nitric acid, 1g of sodium dodecyl sulfate, 3g of sodium citrate, 1g of ethylenediamine tetraacetic acid, 5g of potassium permanganate and a pH value regulator, wherein the pH value regulator is sodium hydroxide, and the pH value of the sealing liquid is regulated to 5.5 by the sodium hydroxide.

(4) Washing and drying: and introducing the copper wire subjected to the sealing treatment into a washing tank for washing, and then introducing the copper wire subjected to washing into an oven for drying. The diameter d of the copper wire is 1.2 mm.

Comparative example 2

This example differs from example 1 in that the method of electroplating copper wire with tin is different, and the step of electroplating copper wire with tin comprises the following steps:

(1) copper wire pretreatment: and (2) carrying out electrotinning on the copper-clad aluminum wire, carrying out alkaline washing, water washing and acid washing on the copper-clad aluminum wire, soaking the copper-clad aluminum wire in alkaline washing liquid of an alkaline washing tank for alkaline washing for 30s, wherein the alkaline washing liquid is 40g/L sodium hydroxide solution. And then moving the steel pipe to a washing tank for washing, placing the steel pipe in a pickling tank for degreasing treatment for 30s after the steel pipe is washed, and moving the steel pipe to the washing tank for washing. The cleaning liquid in the pickling tank comprises 45g/L sulfuric acid, 21g/L polyoxyethylene octylphenol ether, 14g/L triethanolamine, 10g/L sodium chloride, 12g/L citric acid and 13g/L disodium ethylene diamine tetraacetate.

(2) Tinning a copper wire: introducing the pretreated copper wire into a tinning bath for electroplating, wherein a tin plate is fixed in the tinning bath and connected with the positive electrode of a power supply, and the copper wire is connected with the negative electrode of the power supply through a cathode roller; the electroplating process parameter is the current density 2A/dm²The temperature is 20 ℃, and the conveying speed of the copper conductor is 15 m/min;

(3) carrying out soft dissolving treatment: introducing the electroplated copper wire into a heating device, wherein the temperature is 240 ℃, the time of the soft dissolving treatment is 15s, and then pressing by a roller;

(4) washing and drying: and (3) introducing the copper wire subjected to the soft dissolving treatment into a washing tank for washing, and then introducing the washed copper wire into an oven for drying. The diameter d of the copper wire is 1.1 mm.

Comparative example 3

This example is different from comparative example 1 in the compounding ratio of the plating liquid. Each liter of electroplating solution comprises the following raw materials in percentage by weight: 36g of stannous sulfate, 95g of sulfuric acid, 38g of phenolsulfonic acid, 3g of benzoylacetone, 2g of acrylamide, 4g of gelatin, 3g of beta-naphthol, 4g of potassium methanesulfonate, 1.2g of cobalt sulfate, 0.8g of a vanadium salt and a pH regulator, wherein the pH regulator is sodium hydroxide, the pH value of the electroplating solution is regulated to 3.5 by the sodium hydroxide, and the vanadium salt is sodium orthovanadate. The diameter d of the copper wire is 1.1 mm.

Comparative example 4

This example is different from comparative example 1 in the compounding ratio of the plating liquid. Each liter of electroplating solution comprises the following raw materials in percentage by weight: 36g of stannous sulfate, 95g of sulfuric acid, 38g of phenolsulfonic acid, 4g of gelatin, 3g of beta-naphthol, 4g of potassium methylsulfonate, 5g of tartaric acid, 1.2g of cobalt sulfate, 0.8g of vanadium salt, 1.5g of sodium dodecyl sulfate and a pH regulator, wherein the pH regulator is sodium hydroxide, the pH value of the electroplating solution is regulated to 3.5 by the sodium hydroxide, and the vanadium salt is sodium orthovanadate. The diameter d of the copper wire is 1.2 mm.

Comparative example 5

This example is different from comparative example 1 in the compounding ratio of the plating liquid. Each liter of electroplating solution comprises the following raw materials in percentage by weight: 36g of stannous sulfate, 100g of sulfuric acid, 41g of phenolsulfonic acid, 10g of benzoylacetone, 2g of methacrylic acid, 2g of acrylamide, 5.5g of alkylphenol ethoxylates, 4g of gelatin, 3g of beta-naphthol, 15g of potassium methylsulfonate, 15g of tartaric acid, 1.2g of cobalt sulfate, 0.8g of vanadium salt, 1.5g of sodium dodecyl sulfate and a pH regulator, wherein the pH regulator is sodium hydroxide, the pH value of the electroplating solution is regulated to 3.5 by the sodium hydroxide, and the vanadium salt is sodium orthovanadate. The diameter d of the copper wire is 1.2 mm.

The copper wires prepared in examples 1 to 5 and comparative examples 1 to 5 were examined according to the standard of GB 4910-85.

1. Coating thickness detection

And (4) testing by using a plating thickness meter, wherein the plating thickness is (diameter after tinning-diameter before tinning)/2. The standard thickness is not less than 8 mm and not more than 12 mm.

2. Solderability testing

The solderability test was performed on the copper wires after the electrolytic tinning treatment of examples 1 to 5 and comparative examples 1 to 5 by the wet weight method. 20 samples were taken as the samples to be tested for each of examples and comparative examples, and then an average value was taken. The minimum time for the entire wetted sample after cooling was taken as an assessment of the solderability of the deposit. A wetting time of less than 2 seconds is acceptable. The longer the wetting time, the poorer the solderability.

3. Test of adhesion of plating

The plating adhesion was tested according to GB/T4909.11-2009 bare wire test method part 9. And observing and testing the surface coating characterization. The outer peripheral surface of the spirally wound portion of the test should not be blackened, and the plating should be free from cracks.

4. Continuity test of plating

According to the 9 th part of the test method of replacing GB/T4909.9-1985 bare wires by GB/T4909.9-2009, the continuity of the plating layer is tested by a plating layer continuity test-sodium polysulfide method. And observing and testing the surface coating characterization.

According to the 10 th part of the test method of replacing GB/T4909.9-1985 bare wires by GB/T4909.10-2009, the continuity of the plating layer is tested by a plating layer continuity test-ammonium persulfate method. And observing and testing the surface coating characterization.

TABLE 1 test results of tin plating of copper wires in different examples

As shown in Table 1, the tinned copper wires prepared by combining the plating solution and the method of the invention in the examples 1-5 have excellent performance, the prepared products meet the standard, the plating layer is uniform, the surface is smooth, the plating solution of the comparative examples 1-2 is the same as that of the example 1, the preparation method is different, and the prepared tinned copper wire plating layer has poor weldability, adhesiveness and continuity. Comparative examples 3 to 4 were the same as the plating method of example 1, but the plating bath components were different, and the prepared tin-plated copper wire had a thin plating layer, poor solderability, and poor adhesion and continuity. Comparative example 5 the same plating method as in example 1, the same plating bath composition, and a higher content of some components, the tin-plated copper wire produced has a thicker tin plating layer, which exceeds the standard value, and also has an influence on the solderability of the copper wire, and the solderability thereof is slightly lowered, i.e., the solderability property is lowered, as compared with examples 1 to 5.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.