KR102676111B1 - Manufacturing method of busbar for transformer - Google Patents

Abstract

The present invention relates to a method of manufacturing a busbar for a transformer.
A method of manufacturing a busbar for a transformer according to an embodiment of the technical idea of the present invention includes an aluminum base plate forming step (S100) of preparing aluminum (Al) and processing it to form an aluminum base plate; An immersion degreasing and primary washing step (S200) of immersing the aluminum base plate in an alkaline solution, removing impurities on the surface of the aluminum base plate by ultrasonic cleaning, and performing primary washing; A surface treatment and secondary washing step (S300) of activating the surface of the first washed aluminum base plate and then performing a second washing; An etching and third washing step (S400) in which the second washed aluminum base plate is immersed in an etching solution and then washed a third time; A zincate and fourth washing step (S500) of immersing the third washed aluminum base plate in a zincate solution and then fourth washing it; A copper plating step (S600) of manufacturing a copper clad aluminum base plate (Copper Clad Aluminum (CCA)) by plating copper by immersing the fourth washed aluminum base plate in a copper plating solution; and a tin plating step (S700) of manufacturing a busbar by plating tin on the copper-plated aluminum base plate.
With the above configuration, the method of manufacturing a busbar for a transformer according to various embodiments of the technical idea of the present invention has no corrosion between dissimilar metals, minimizes copper consumption, lowers the manufacturing cost and product price, and provides a transformer with excellent bonding characteristics. Busbars can be manufactured.

Description

Manufacturing method of busbar for transformer {MANUFACTURING METHOD OF BUSBAR FOR TRANSFORMER}

The present invention relates to a method of manufacturing a busbar for a transformer, and more specifically, to a method of manufacturing a busbar for a transformer that supplies current to a transformer from the outside or discharges current from the transformer to an electric device.

Busbar, a medium for transmitting electrical energy, has the advantage of being able to transmit more electrical energy with the same volume of conductor. Because of these advantages, busbars are widely used as a replacement for electric cables in various industrial fields, including buildings that require large amounts of electric energy such as power plants, large buildings, and large factories, as well as machinery and transportation equipment that use electric energy.

Previously, it was common to manufacture busbars using copper or aluminum materials, but copper busbars are expensive and heavy, which can lead to problems with the durability of the product and when used in transportation equipment. This may cause the problem of mileage loss due to increase.

On the other hand, aluminum busbars are lighter and cheaper than copper, but due to low electrical conductivity, there is a problem of low transmission efficiency of electrical energy, and the heat generated when energized may lead to the need to install a cooler depending on the usage environment. there is.

To reduce the cost and lighten the busbar while maintaining electrical conductivity, an aluminum-copper heterojunction type busbar can be used. However, galvanic corrosion occurs due to local electrolysis between dissimilar metals at the aluminum and copper interface, resulting in a decrease in bonding strength or durability, making it difficult to use in high-voltage busbars or electric vehicle busbars that require high durability. there is.

As a prior document regarding busbars, Registered Patent Publication No. 10-0603021, “Copper-aluminum clad busbar with added silver coating layer and manufacturing method thereof” (registered on July 12, 2006), has a thickness of 1 to 500㎛ on the surface. A method of manufacturing a busbar with a copper-silver-aluminum laminate structure is disclosed by injecting a silver-plated aluminum bar into a copper pipe and extruding it at 300°C. However, problems may occur such as defects occurring when bonding between aluminum and copper, defects occurring when the bonding between aluminum and copper is not strong, and interfacial defects due to galvanic corrosion caused by the potential difference between aluminum and copper. .

In addition, in Registered Patent Publication No. 10-1362328, “Copper/aluminum clad material with improved strength and interfacial reliability by alloying and manufacturing method thereof” (registered on February 6, 2014), aluminum material and copper material are arranged in a concentric circle. A layered structure is disclosed. In order to increase the reliability of the copper-aluminum interface, 0.01 to 5% of Cr, Zr, Mn, Co, etc. are added and joined by methods such as rolling, extrusion, drawing, and friction welding.

In addition, Registered Patent Publication No. 10-2034011, “Busbar Manufacturing Method” (registered on October 14, 2019), is a method of manufacturing busbars that can be firmly joined to each other by friction welding bar-shaped copper to both ends of bar-shaped aluminum. It is disclosed about. However, because the bonding interface between aluminum and copper is exposed on the surface, the problem of interfacial defects due to galvanic corrosion still exists.

Domestic registered patent No. 10-2290087 (registered on August 10, 2021) Domestic registered patent No. 10-1421028 (registered on July 14, 2014) Domestic registered patent No. 10-1517049 (registered on April 27, 2015)

The problem to be solved by the present invention is to provide a method of manufacturing a busbar for a transformer that does not cause corrosion between dissimilar metals, reduces the manufacturing cost and product price by minimizing copper consumption, and has excellent bonding characteristics.

The various problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

In one embodiment of the technical idea of the present invention, a method of manufacturing a busbar for a transformer is disclosed.

The manufacturing method of the transformer busbar includes an aluminum base plate forming step (S100) of preparing aluminum (Al) and processing it to form an aluminum base plate; An immersion degreasing and primary washing step (S200) of immersing the aluminum base plate in an alkaline solution, removing impurities on the surface of the aluminum base plate by ultrasonic cleaning, and performing primary washing; A surface treatment and secondary washing step (S300) of activating the surface of the first washed aluminum base plate and then performing a second washing; An etching and third washing step (S400) in which the second washed aluminum base plate is immersed in an etching solution and then washed a third time; A zincate and fourth washing step (S500) of immersing the third washed aluminum base plate in a zincate solution and then fourth washing it; A copper plating step (S600) of manufacturing a copper clad aluminum base plate (Copper Clad Aluminum (CCA)) by plating copper by immersing the fourth washed aluminum base plate in a copper plating solution; and a tin plating step (S700) of manufacturing a busbar by plating tin on the copper-plated aluminum base plate.

Specific details of other embodiments are included in the detailed description.

The manufacturing method of a transformer busbar according to various embodiments of the technical idea of the present invention has no corrosion between dissimilar metals, minimizes copper consumption, lowers the manufacturing cost and product price, and manufactures a transformer busbar with excellent bonding characteristics. You can.

It will be fully understood that various embodiments of the technical idea of the present invention can provide various effects that are not specifically mentioned.

1 is a flowchart illustrating a method of manufacturing a busbar for a transformer according to an embodiment of the technical idea of the present invention.
Figure 2 is a photograph showing an example of a tin-plated busbar for a transformer according to an embodiment of the technical idea of the present invention.
Figure 3 is a photograph showing an example of a transformer installed with a busbar manufactured according to an embodiment of the technical idea of the present invention.

The advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described in detail below. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure will be thorough and complete and so that the spirit of the invention can be sufficiently conveyed to those skilled in the art.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as having an ideal or excessively formal meaning unless explicitly defined in the present application. No.

Hereinafter, with reference to the attached drawings, a method of manufacturing a busbar for a transformer according to an embodiment of the technical idea of the present invention will be described in detail with preferred embodiments.

Figure 1 is a flow chart for explaining a method of manufacturing a busbar for a transformer according to an embodiment of the technical idea of the present invention, and Figure 2 is a tin-plated busbar for a transformer according to an embodiment of the technical idea of the present invention. This is a photograph showing an example, and Figure 3 is a photograph showing an example of a transformer installed with a busbar manufactured according to an embodiment of the technical idea of the present invention.

1 to 3, the method of manufacturing a busbar for a transformer according to an embodiment of the technical idea of the present invention includes an aluminum base plate forming step (S100), an immersion degreasing and first washing step (S200), and surface treatment. and a second washing step (S300), an etching and third washing step (S400), a zincate and fourth washing step (S500), a copper plating step (S600), and a tin plating step (S700).

1. Aluminum base plate forming step (S100)

The aluminum base plate preparation step (S100) is a step of preparing aluminum (Al) and processing it into a predetermined size and shape through mechanical processing to form an aluminum base plate.

Aluminum (Al) naturally has an aluminum oxide layer on its surface to protect its inner surface, so it has excellent corrosion resistance and malleability, making it easy to mold and cut. The electrical conductivity of aluminum is good at about 60% of that of copper, and thermal conductivity is also excellent.

2. Immersion degreasing and first washing step (S200)

The immersion degreasing and primary washing step (S200) is a step of immersing the aluminum base plate in an alkaline solution, removing impurities such as dust or oily substances attached to the surface of the aluminum base plate by ultrasonic cleaning, and performing primary washing. .

In the immersion degreasing and first washing step (S200), the alkaline solution may be a sodium hydroxide (NaOH) solution. Specifically, the ultrasonic cleaning is performed at a temperature of 50 to 60° C., a voltage of 1 to 3 V, and a voltage of 8 g/L to 8 g/L. It can be performed for 10 to 30 seconds in a sodium hydroxide (NaOH) solution at a concentration of 12 g/L.

3. Surface treatment and second washing step (S300)

The surface treatment and second washing step (S300) is a step of activating the surface of the first washed aluminum base plate and then performing second washing.

The surface treatment and second washing step (S300) removes impurities remaining in the first washed aluminum base plate and at the same time removes the black, loose surface film that has no cohesion created in the previous process to activate the aluminum plate surface. For example, activation of the surface of the first washed aluminum base plate may be performed using chromic acid.

Specifically, in the surface treatment and second washing step (S300), the first washed aluminum base plate is immersed in a chromic acid solution at a temperature of 40 to 50 ° C. and a concentration of 20 g / L to 30 g / L for 40 to 60 seconds to form a surface. After treatment, it can be washed a second time.

4. Etching and third washing step (S400)

The etching and third washing step (S400) is a third washing step after immersing the second washed aluminum base plate in an etching solution.

The etching and third washing step (S400) can improve the adhesion of the aluminum base plate by immersing the second washed aluminum base plate in an etching solution to remove the natural oxide film and corrode it micronically. The secondary washing step (S400) may be performed by immersing the secondary washing aluminum base plate in an etching solution at a temperature of 40 to 50° C. for 15 to 25 seconds, then separating and washing the aluminum base plate a third time.

Additionally, in the etching and third washing step (S400), the etching solution includes nitric acid, amino acids, persulfate, potassium monopersulfate, a chelating agent, an alkyltetrazole-based compound, a surfactant, and deionized water.

In addition, the etching solution contains 1 to 3% by weight of nitric acid, 0.1 to 1.5% by weight of amino acid, 0.1 to 0.5% by weight of persulfate, 1 to 3% by weight of potassium monopersulfate, 0.1 to 1.5% by weight of chelating agent, and an alkyltetrazole-based compound. It may include 0.1 to 1% by weight, 0.01 to 0.05% by weight of surfactant, and a balance of deionized water satisfying 100% by weight.

The nitric acid may be included in the etching solution to function as an oxidizing agent. The nitric acid may be included in a weight ratio of 1 to 3% by weight based on the total content of the etching solution.

In the present invention, if the nitric acid is contained in less than 1% by weight, the etching speed of the aluminum base plate may decrease, resulting in poor etching uniformity, which may cause staining, and if the nitric acid is contained in more than 3% by weight, The etching speed may be excessive, which may cause problems in subsequent processes.

The amino acid provides an environment in which the aluminum base plate can be etched simultaneously, buffers against changes in acidity, and acts as a sequestering agent for metal ions.

In the present invention, the amino acid is an amino acid having 3 to 10 carbon atoms, and the amino acid may be any one or more selected from the group consisting of isoleucine, arginine, proline, tyrosine, glutamic acid, glutamine, and glycine.

In the present invention, the amino acid may be included in an amount of 0.1 to 1.5% by weight in the total content of the etching solution. If the amino acid is included in less than 0.1% by weight, a problem may occur in which the effect of the amino acid is not sufficiently apparent, and 1.5% by weight may be used. If it is included in excess, the aluminum base plate may be excessively etched or the buffering effect against changes in acidity may be reduced.

The persulfate is a substance used as an oxidizing agent to etch the aluminum base plate. The persulfate allows the etching of the aluminum base plate to be easily performed. In addition, the aluminum base plate is etched to an appropriate amount and has an excellent etching profile. can be formed.

That is, the persulfate may be used by mixing ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ) and sodium persulfate (Na ₂ S ₂ O ₈ ) at a weight ratio of 1:1.

In the present invention, the persulfate may be included in a weight ratio of 0.1 to 0.5% by weight in the total content of the etching solution, but if the persulfate is included in less than 0.1% by weight, the persulfate content is small and does not function sufficiently as an oxidizing agent. may occur, and if it is included in excess of 0.5% by weight, the relative content of persulfate may be excessive and overetching of the aluminum base plate may occur.

The potassium monopersulfate is included to oxidize the aluminum base plate and improve etching uniformity, and is potassium hydrogen peroxymonosulfate having an active oxygen content of 0.05% by weight to 0.35% by weight. peroxymonosulfate), which is commercially available in concentrated form from Du Pont (E. I. du Pont de Nemours and Company, Wilmington, DE) and can be diluted for use.

The potassium monopersulfate is sold commercially as an OXONE monopersulfate compound, and is a commercially available mixed triple salt (2KHSO ₅ ㆍKHSO ₄ ㆍK ₂ SO ₄ ), a process disclosed in U.S. Patent No. 7,442,323. It can be prepared according to.

Additionally, the term “active oxygen (AO)” refers to the amount of excess atomic oxygen present in the corresponding reduced form of the compound, and the active oxygen can be expressed in weight percent. For example, in the case of KHSO ₅ , it has a reduced form of KHSO ₄ , and active oxygen can be calculated using the following [calculation formula].

[ formula ]

In addition, in the present invention, the potassium monopersulfate may be included in an amount of 1 to 3% by weight in the total content of the etching solution. If the potassium monopersulfate is included in less than 1% by weight, the aluminum base Problems may arise such that it may be difficult to oxidize the plate or ensure etching uniformity, and if it is included in excess of 3% by weight, problems may occur where physical properties are deteriorated due to overetching of the aluminum base plate.

When the number of processed aluminum base plates to be etched increases, the chelating agent may be added to prevent a decrease in the etching ability of the etching solution caused by increased metal ions and to prevent aluminum from being re-adsorbed.

The chelating agent may be included in an amount of 0.1 to 1.5% by weight in the total content of the etching solution. If the chelating agent is included in less than 0.1% by weight, it may be difficult to sufficiently perform the function of preventing re-adsorption of aluminum ions, and 1.5% by weight If it is included in excess of %, a problem may occur where the etching speed is reduced.

In the present invention, diethylene trinitrilo pentaacetic acid (DTPA) and glutamic acid-2-acetic acid may be used as the chelating agent mixed in a weight ratio of 1:1.

The alkyltetrazole-based compound acts as an etching inhibitor and can control the etching rate. The alkyltetrazole-based compound is one or more selected from the group consisting of 5-methyl tetrazole, 5-ethyl tetrazole, and 5-propyl tetrazole. This can be used.

In the present invention, the alkyltetrazole-based compound may be included in an amount of 0.1 to 1% by weight in the total content of the etching solution. However, if the alkyltetrazole-based compound is included in less than 0.1% by weight, a problem may occur in which the effect of etching control is not sufficiently achieved. If it is included in excess of 1% by weight, etching may be delayed and physical properties may deteriorate.

The surfactant may be added to improve the penetration of the etching solution into the aluminum base plate and to allow the etching solution to easily flow onto the surface of the aluminum base plate.

In the present invention, the surfactant may be one or more selected from the group consisting of glycerol, triethylene glycol, and polyethylene glycol, preferably triethylene glycol. .

In addition, the surfactant may be included in a weight ratio of 0.01 to 0.03% by weight in the total content of the etching solution. If the surfactant is included in less than 0.01% by weight, a problem of deterioration in etching uniformity may occur, and 0.05% by weight. If it is contained in excess of %, problems such as excessive foaming and deterioration of the physical properties of the etching solution may occur.

The deionized water is one in which ions in water have been removed, and it is desirable to use deionized water having a resistivity of 18 MΩ·cm or more.

5. Zincate and 4th washing step (S500)

The zincate and fourth washing step (S500) is a fourth washing step after immersing the third washed aluminum base plate in a zincate solution.

In the zincate and fourth washing step (S500), Zn ²⁺ is precipitated and zinc is precipitated on the aluminum surface due to a chemical reaction on the surface of the aluminum base plate by the zincate solution, and at the same time, Al ³⁺ is oxidized from the aluminum material. The zincate layer that falls off is a fugitive coating that is removed during the subsequent metal plating process, which corresponds to the oxidation layer removal and activation process on the surface, thereby imparting conductivity to the aluminum film.

In other words, the zincate is a process that uses the potential difference between the aluminum surface and the zinc in the zincate solution to replace zinc nuclei on the aluminum surface so that other metals such as copper can be directly plated.

In the zincate and fourth washing step (S500), the third washed aluminum base plate can be immersed in a zincate solution for 20 to 40 seconds and then washed fourthly. The zincate solution is zinc acetate (Zinc). acetate, nickel sulfate, cobalt sulfate, ammonium acetate, ammonium bifluoride, malic acid, bismuth oxide and thiourea. Includes.

That is, the zincate solution contains 25 to 35 parts by weight of zinc acetate, 65 to 75 parts by weight of nickel sulfate, 3 to 7 parts by weight of cobalt sulfate, and 20 parts by weight of ammonium acetate. to 30 parts by weight, ammonium bifluoride 4 to 8 parts by weight, malic acid 25 to 35 parts by weight, bismuth oxide 0.5 to 1.5 parts by weight, and thiourea 0.05 to 0.15 parts by weight. It may be included in a weight ratio of parts, preferably the zincate solution contains 30 parts by weight of zinc acetate, 70 parts by weight of nickel sulfate, 5 parts by weight of cobalt sulfate, and ammonium acetate. ) 25 parts by weight, 6 parts by weight of ammonium bifluoride, 30 parts by weight of malic acid, 1 part by weight of bismuth oxide, and 0.1 part by weight of thiourea.

6. Copper plating step (S600)

The copper plating step (S600) is a step of manufacturing a copper clad aluminum base plate (Copper Clad Aluminum (CCA)) by plating copper by immersing the fourth washed aluminum base plate in a copper plating solution.

For example, in the copper plating step (S600), the washed aluminum base plate is immersed in a copper plating solution containing 150 to 250 g/l of copper sulfate, 50 to 80 g/l of sulfuric acid, and 50 to 150 ml of chlorine ions. Copper can be plated to surround the aluminum base plate by applying a voltage of 1.5 to 6V and a current of 1 to 10A at a temperature of 20 to 40° C., by plating copper on the aluminum base plate to form a copper-clad aluminum base. Since the configuration for manufacturing a plate (Copper Clad Aluminum (CCA)) is a known technology, detailed description thereof will be omitted for convenience of explanation and clarity of the technical idea of the present invention.

7. Tin plating step (S700)

The tin plating step (S700) is a step of manufacturing a busbar by plating tin on the copper-plated aluminum base plate.

In general, copper exposed to the outside is soft and is easily damaged or corroded by external shocks. In the tin plating step (S700), the busbar is manufactured by plating tin on the copper-plated aluminum base plate, making it resistant to external shocks. Busbars that are safer and have improved physical properties can be manufactured.

Since the configuration of plating tin on the copper-plated aluminum base plate in the tin plating step (S700) is a known technique, detailed description thereof will be omitted for convenience of explanation and clarity of the technical idea of the present invention.

Meanwhile, a busbar generally has a laminated structure of an aluminum layer, a copper layer surrounding the aluminum layer, and a tin layer surrounding the copper layer, and tin is plated on copper-clad aluminum (CCA (Copper Clad Aluminum)). When forming a tin layer, if the surface is made of only copper, no problems occur during plating, but if the tin layer is formed by plating tin on the exposed aluminum surface, plating defects may occur.

In other words, when a busbar made of copper clad aluminum (CCA (Copper Clad Aluminum)) is cut short or an electrically connected hole is formed, the cut surface or hole portion is Aluminum is exposed to the outside, and a two-component cross-sectional structure consisting of an aluminum layer and a copper layer is discharged.

If tin is plated to form a tin layer in this state, plating is not done or only partially plated, and corrosion occurs due to the potential difference between aluminum and tin dissimilar metals, resulting in defects.

In order to solve the above problem, in the tin plating step (S700), if the copper-plated aluminum base plate is cut short or an electrically connected hole is formed to expose the inner aluminum layer to the outside, copper plating is performed. By performing the process again, the entire surface of the aluminum base plate can be plated with copper without exposing aluminum, making it possible to easily perform tin plating in a later process.

Hereinafter, a method of manufacturing a busbar for a transformer according to an embodiment of the technical idea of the present invention will be described in detail with reference to the attached drawings. The following examples are intended to illustrate the present invention, but the present invention is not limited to the following examples and may be modified and changed in various ways.

<Example>

First, an aluminum base plate was prepared, and the aluminum base plate was immersed in an alkaline solution, and then impurities such as dust and oily substances attached to the surface of the aluminum base plate were removed by ultrasonic cleaning and then first washed with water.

At this time, the ultrasonic cleaning was performed for 20 seconds at a temperature of 55°C, a voltage of 2V, and a sodium hydroxide (NaOH) solution with a concentration of 10g/L.

Next, the first washed aluminum base plate was surface treated by immersing it in a chromic acid solution at a temperature of 45°C and a concentration of 25 g/L for 50 seconds, and then washed a second time.

Next, the second washed aluminum base plate was immersed in an etching solution at a temperature of 45°C for 20 seconds, then separated and washed a third time. The etching solution contained 2% by weight of nitric acid, 1% by weight of amino acid, and 0.3% by weight of persulfate. It was prepared by mixing 2% by weight of potassium monopersulfate, 1% by weight of chelating agent, 0.5% by weight of alkyltetrazole-based compound, 0.03% by weight of surfactant, and the remaining amount of deionized water satisfying 100% by weight.

Subsequently, the aluminum base plate washed three times was immersed in a zincate solution and then washed four times.

At this time, the zinc acetate solution contains 30 parts by weight of zinc acetate, 70 parts by weight of nickel sulfate, 5 parts by weight of cobalt sulfate, 25 parts by weight of ammonium acetate, and ammonium bifluoride. It was prepared by mixing 6 parts by weight of Ammonium bifluoride, 30 parts by weight of malic acid, 1 part by weight of Bismuth oxide, and 0.1 part by weight of Thiourea.

Next, a copper clad aluminum base plate (CCA (Copper Clad Aluminum)) was manufactured by plating copper by immersing the fourth washed aluminum base plate in a copper plating solution, and the copper clad aluminum base plate ( A busbar as shown in FIG. 2 was manufactured by plating tin on CCA (Copper Clad Aluminum).

At this time, the copper plating was performed by immersing the fourth time washed aluminum base plate in a copper plating solution containing 200 g/l of copper sulfate, 65 g/l of sulfuric acid, and 100 ml of chlorine ion, at a temperature of 30°C, at a voltage of 3.5V and 5A. Copper was plated to surround the aluminum base plate by applying a current.

Above, a preferred embodiment of the present invention has been described with reference to the attached drawings, but those skilled in the art will understand that the present invention can be modified in another specific form without changing its technical idea or essential features. You will understand that it can be done. Therefore, the embodiment described above should be understood as illustrative in all respects and not restrictive.

Claims (4)

An aluminum base plate forming step (S100) of preparing aluminum (Al) and processing it to form an aluminum base plate;
An immersion degreasing and primary washing step (S200) of immersing the aluminum base plate in an alkaline solution, removing impurities on the surface of the aluminum base plate by ultrasonic cleaning, and performing primary washing;
A surface treatment and secondary washing step (S300) of activating the surface of the first washed aluminum base plate and then performing a second washing;
An etching and third washing step (S400) in which the second washed aluminum base plate is immersed in an etching solution and then washed a third time;
A zincate and fourth washing step (S500) of immersing the third washed aluminum base plate in a zincate solution and then fourth washing it;
A copper plating step (S600) of manufacturing a copper clad aluminum base plate (Copper Clad Aluminum (CCA)) by plating copper by immersing the fourth washed aluminum base plate in a copper plating solution; and
A method of manufacturing a busbar for a transformer, comprising a tin plating step (S700) of manufacturing a busbar by plating tin on the copper-plated aluminum base plate. According to clause 1,
The immersion degreasing and first washing step (S200) involves ultrasonic washing for 10 to 30 seconds in a sodium hydroxide (NaOH) solution at a temperature of 50 to 60°C, a voltage of 1 to 3V, and a concentration of 8 g/L to 12 g/L, followed by first washing. Wash your hands,
In the surface treatment and second washing step (S300), the first washed aluminum base plate is surface treated by immersing it in a chromic acid solution at a temperature of 40 to 50° C. and a concentration of 20 g/L to 30 g/L for 40 to 60 seconds. Second washing,
In the etching and third washing step (S400), the etching solution contains nitric acid, amino acids, persulfate, potassium monopersulfate, a chelating agent, an alkyltetrazole-based compound, a surfactant, and deionized water,
In the zincate and fourth washing step (S500), the third washed aluminum base plate is immersed in a zincate solution for 20 to 40 seconds and then washed fourthly, wherein the zincate solution is zinc acetate. ), Nickel sulfate, Cobalt sulfate, Ammonium acetate, Ammonium bifluoride, Malic acid, Bismuth oxide and Thiourea. A method of manufacturing a busbar for a transformer, comprising: According to clause 2,
In the etching and third washing step (S400), the etching solution contains 1 to 3% by weight of nitric acid, 0.1 to 1.5% by weight of amino acid, 0.1 to 0.5% by weight of persulfate, 1 to 3% by weight of potassium monopersulfate, and 0.1% by weight of chelating agent. to 1.5% by weight, 0.1 to 1% by weight of an alkyltetrazole-based compound, 0.01 to 0.05% by weight of a surfactant, and a remaining amount of deionized water satisfying 100% by weight. According to clause 3,
In the zincate and fourth washing step (S500), the zincate solution contains 25 to 35 parts by weight of zinc acetate, 65 to 75 parts by weight of nickel sulfate, and 3 to 7 parts by weight of cobalt sulfate. Parts by weight, Ammonium acetate 20 to 30 parts by weight, Ammonium bifluoride 4 to 8 parts by weight, Malic acid 25 to 35 parts by weight, Bismuth oxide 0.5 to 1.5 parts by weight and Thiourea in a weight ratio of 0.05 to 0.15 parts by weight.