CN111593376A

CN111593376A - Method for electrodepositing bright copper

Info

Publication number: CN111593376A
Application number: CN202010542520.0A
Authority: CN
Inventors: 李志刚; 葛文
Original assignee: Shenzhen Colorful Jewelry Development Co ltd
Current assignee: Shenzhen Colorful Jewelry Development Co ltd
Priority date: 2020-06-15
Filing date: 2020-06-15
Publication date: 2020-08-28

Abstract

The invention relates to a method for electrodepositing bright copper, which comprises the following steps: performing surface treatment on the core mold; taking the surface-treated core mold as a cathode, and taking two metal plates as a first anode plate and a second anode plate respectively; parameters of the double pulse circuit are set, and a copper coating is formed on the surface of the cathode in an electroplating mode under stirring conditions. According to the method for electrodepositing bright copper, the double-pulse circuit is adopted to electroplate on the surface of the core mould to form the copper plating layer, and through the electroplating solution matched with the double-pulse circuit and the combination of the data of the specific embodiment, the method for electrodepositing bright copper can improve the uniformity and the flatness of the copper plating layer obtained by electrodeposition compared with the traditional method for electrodepositing bright copper, and the copper plating layer obtained by the method for electrodepositing bright copper has higher brightness.

Description

Method for electrodepositing bright copper

Technical Field

The invention relates to the field of jewelry manufacturing, in particular to a method for electrodepositing bright copper.

Background

With the increasing consumption of gold ornaments in the world, China has become the first gold producing country and consuming country in the world, the requirements of people on the quality, the volume, the hardness and the like of the gold ornaments are higher and higher, the modeling requirements are more and more diverse, and therefore higher and more rigorous requirements are provided for the manufacturing process of the gold ornaments. Because the traditional gold ornaments have the defects of single style, stiff shape, soft quality, easy deformation and no wear resistance, the 3D hard gold ornaments have been produced, the defects of the traditional gold ornaments are overcome, and the 3D hard gold ornaments are deeply loved by consumers due to vivid're-carving' property and high cost performance.

The 3D hard gold is produced by adopting the electroforming technology, which is a great progress of jewelry manufacturing industry, overcomes the defects of simple shape, stiff shape and single type of traditional gold ornaments, and is especially suitable for manufacturing hollow gold ornaments, and products manufactured by the electroforming gold process have changeable shape, unique shape and rich styles.

Compared with the traditional casting technology, the gold electroforming technology has the greatest advantages that smaller gold raw materials are used for manufacturing larger, lighter, thinner and more precise products, and the ornaments are fashionable and exquisite in appearance, large in size, light in weight and high in cost performance and are widely accepted by young consumers.

At present, the production technologies of hard pure gold electroforming technology, electroforming K gold, 3D hard gold technology, silver electroplating technology and the like are generally applied to the jewelry industry. The core of these techniques is the process of making a metal article by electrochemical deposition of metal on a cathode mandrel followed by stripping to separate the metal from the mandrel. The electroforming can produce some metal ornaments with special shapes which are difficult to be produced by common machining methods, and has the main advantages that: 1. by reasonable core mold design and proper process range selection, parts with high precision and low surface roughness can be manufactured; 2. the inner profile processing which is difficult to realize can be converted into the outer profile processing which is easy to realize; 3. the electroforming has excellent repeated engraving performance and can accurately restore the surface appearance of the core mold; 4. the electroforming method can be used for connecting some special materials which cannot be welded; 5. can obtain metal ornaments with high purity and parts with multilayer structures, and can combine various metal and nonmetal parts into a whole; 6. the thickness of the electroformed layer can be controlled. By adjusting the technological parameters of current density, current time, etc., the foil with thickness of several micrometers can be made, and the structural parts with thickness of tens of millimeters can also be made.

The main defects of the electroforming technology are long production period, high cost, uniform thickness of an electroforming layer and difficult control, and especially, structural defects such as scratches and scratches on the surface of a core mold can be repeatedly engraved on the surface of the electroforming layer, so that a large number of defective products are generated, and resources are wasted. Aiming at the problems, the purity, the brightness and other performances of the gold jewelry are generally improved by adjusting the formula of the electroforming solution and adjusting various parameters in the electroforming process. The power supply adopted by the existing electroforming technology for producing the 3D hard gold is basically a direct current power supply, the improvement of the electroforming technology is usually biased to the formula of electroforming liquid, and the problems of surface flatness and brightness of a core mold cannot be fundamentally solved by single technical improvement no matter direct current or the formula of electrolyte is improved; solves the problem of repeated engraving caused by the structural defects of scratches, scuffing and the like.

In conclusion, the method for manufacturing high-quality 3D hard gold, which reduces the generation of defective products and defective products, shortens the process period, reduces the cost and improves the production efficiency, is a key bottleneck problem of technical pain and industrial development in precision manufacturing in jewelry industry, and one of the focused cores is to improve and improve the surface flatness and brightness of a core mold material, the structural defect without scratches, the full coverage of electrodeposited bright copper on the surface of the core mold and the like. At present, the core die material in China generally adopts low-melting-point tin-bismuth alloy, low-temperature alloy or wax piece silver spraying oil, and the alloy has the characteristics of low melting point, good fluidity, difficult segregation, easy filling, high manufacturing speed, capability of pressing a die with a complex geometric shape, reusability of the alloy and lower pressing cost.

The technology is established on the basis of direct current and the existing copper sulfate type electrolyte, but the technology has the defects and shortcomings in the aspects of coping with the core mould with complex geometric shape and various styles and improving high-performance and high-quality gold ornaments, and cannot meet the requirements of high-end precision manufacturing and intelligent manufacturing development of the industry.

The copper sulfate type electrolyte has the advantages of simple components, stability, environmental protection, easy recovery and treatment of waste liquid, high current efficiency, bright plating layer and the like, and has replaced alkaline cyanide type copper plating and pyrophosphate type copper plating to become a main process formula of the electrodeposited bright copper.

Disclosure of Invention

In view of the above, there is a need for a method for electrodepositing bright copper, which can improve the uniformity and flatness of the copper coating obtained by electrodeposition.

A method of electrodepositing bright copper comprising the steps of:

performing surface treatment on the core mold;

the core mold after surface treatment is used as a cathode, two metal plates are respectively used as a first anode plate and a second anode plate, the cathode, the first anode plate and the second anode plate are immersed into electroplating solution, and the cathode, the first anode plate and the second anode plate are connected into a double-pulse circuit, wherein the electroplating solution comprises 150 g/L-220 g/L copper sulfate, 50 g/L-70 g/L concentrated sulfuric acid, 0.01 g/L-0.02 g/L sodium polydithio dipropyl sulfonate, 0.0002 g/L-0.0007 g/L ethylene thiourea, 0.00003 g/L-0.001 g/L2-mercaptobenzimidazole, 0.04 g/L-0.1 g/L polyethylene glycol and 0.02 g/L-0.08 g/L chloride ions; and

and setting parameters of the double-pulse circuit, and electroplating on the surface of the cathode under stirring conditions to form a copper coating.

According to the method for electrodepositing bright copper, the double-pulse circuit is adopted to electroplate on the surface of the core mould to form the copper plating layer, and through the electroplating solution matched with the double-pulse circuit and the combination of the data of the specific embodiment, the method for electrodepositing bright copper can improve the uniformity and the flatness of the copper plating layer obtained by electrodeposition compared with the traditional method for electrodepositing bright copper, and the copper plating layer obtained by the method for electrodepositing bright copper has higher brightness.

Specifically, the sodium polydithio-dipropyl sulfonate can play a role in refining crystal grains and preventing high-region scorching in a copper plating process, and when the sodium polydithio-dipropyl sulfonate and the 2-mercaptobenzimidazole are jointly used and added into the electroplating solution, the electroplating solution has good long-acting property, less decomposition products and low consumption of a light-emitting agent. The 2-mercaptobenzimidazole can plate a full-bright coating with excellent leveling property and good toughness in a wide temperature range in the acid copper process, is a good brightening agent and leveling agent, can expand the brightness range of the coating, and can play the role of ethylene thiourea to the maximum when the 2-mercaptobenzimidazole and the ethylene thiourea are jointly used and added into the electroplating solution.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Wherein:

FIG. 1 is a flow chart of a method of electrodepositing bright copper in one embodiment.

Fig. 2 is a schematic reaction diagram of the method of electrodepositing bright copper as shown in fig. 1.

Fig. 3 is a schematic structural view of a hall cell according to an embodiment.

FIG. 4 is a photograph comparing the products obtained in examples 1 to 4 and comparative examples 1 to 4.

FIG. 5a is a photomicrograph taken at 500 times magnification of the copper plating layer obtained in comparative example 1.

FIG. 5b is a photomicrograph taken at 500 Xmagnification of the copper plating layer obtained in example 1.

Fig. 6a is an SEM image of the copper plating layer prepared in comparative example 1.

FIG. 6b is an SEM image of the copper plating made in example 1.

Detailed Description

In order that the invention may be more fully understood, reference will now be made to the following description taken in conjunction with the accompanying drawings. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Referring to fig. 1 and 2, one embodiment of a method for electrodepositing bright copper includes the steps of:

and S10, performing surface treatment on the core mold.

Generally, the core mold can be a tin-bismuth alloy core mold, a low-temperature alloy or a wax piece sprayed with silver oil.

Surface treatment of the core mold: and sequentially polishing the core mold by using 400-mesh metallographic abrasive paper, 800-mesh metallographic abrasive paper, 1200-mesh metallographic abrasive paper, 2000-mesh metallographic abrasive paper, polishing, ultrasonic cleaning, primary spraying water passing, electrolytic oil removal, secondary spraying water passing, activated acid etching and tertiary spraying water passing to finish the surface treatment of the core mold.

Preferably, when the surface treatment is performed on the wax member, after the surface of the wax member is polished, a layer of conductive oil is sprayed on the surface of the wax member, and then the subsequent operations such as ultrasonic cleaning and the like are continued.

The first time of spraying water can be 10 seconds to pass through the 2 cylinders for 5 seconds, the second time of spraying water can be 5 seconds to pass through the 2 cylinders for 5 seconds, and the third time of spraying water can be 5 seconds to pass through the 4 cylinders for 10 seconds.

Specifically, the ultrasonic cleaning time is 20-40 s, and the temperature is 80-95 ℃; the time of electrolytic degreasing is 1 min-2 min, and the temperature is 42-45 ℃; the time of activating acid etching is 10-15 s, and the temperature is 25-30 ℃.

The ultrasonic cleaning aims at removing wax, grinding, polishing and cleaning, and mainly removes stains on the surface of a plated part, so that the adhesion of a copper layer at the later stage is facilitated, and the procedure is strictly in accordance with the sequence of the operation flow, and the sequence is strictly forbidden to be reversed and omitted.

S20, using the mandrel after surface treatment as the cathode 10, using two metal plates as the first anode plate 20 and the second anode plate 30, respectively, immersing the cathode 10, the first anode plate 20 and the second anode plate 30 in the plating solution, and connecting the cathode 10, the first anode plate 20 and the second anode plate 30 into the double pulse circuit.

The electroplating solution comprises 150 g/L-220 g/L copper sulfate, 50 g/L-70 g/L concentrated sulfuric acid, 0.01 g/L-0.02 g/L sodium polydithio-dipropyl sulfonate, 0.0002 g/L-0.0007 g/L ethylene thiourea, 0.00003 g/L-0.001 g/L2-mercaptobenzimidazole, 0.04 g/L-0.1 g/L polyethylene glycol and 0.02 g/L-0.08 g/L chloride ions.

Referring to fig. 2, a first anode plate 20 and a second anode plate 30 are disposed opposite to each other and spaced apart from each other, and a cathode 10 is disposed between the first anode plate 20 and the second anode plate 30.

This arrangement ensures that the copper plating is formed uniformly on both sides of the cathode 10.

Generally, the first anode plate 20 and the second anode plate 30 are both surface-treated phosphor-copper plates.

The surface treatment operation of the phosphor-copper plate may be: and sequentially polishing 800 meshes of metallographic abrasive paper, 1200 meshes of metallographic abrasive paper and 2000 meshes of metallographic abrasive paper on the phosphorus copper plate, and spraying water to finish the surface treatment of the phosphorus copper plate.

And S30, setting parameters of the double-pulse circuit, and electroplating on the surface of the cathode 10 under stirring conditions to form a copper coating.

According to the method for electrodepositing bright copper, the double-pulse circuit is adopted to electroplate on the surface of the core mould to form the copper coating, the optimization electroplating solution matched with the double-pulse circuit is designed through a Hull cell experiment, and data of a specific embodiment are combined, so that compared with the traditional method for electrodepositing bright copper, the method for electrodepositing bright copper can improve the uniformity and the flatness of the copper coating obtained by electrodeposition, and the brightness of the copper coating obtained by the method for electrodepositing bright copper is higher.

Preferably, the parameters of the double pulse circuit are set as follows: forward current density 2.0A/dm²～7.0A/dm²The forward duty ratio is 50-60%, the reverse duty ratio is 10-20%, the forward period is 4-10 ms, and the reverse period is 1-4 ms.

In this embodiment, after the parameters of the double pulse circuit are determined, an optimized plating solution adapted to the double pulse circuit can be designed by a Hull cell experiment.

Referring to FIG. 3, the concentration of the plating solution was adjusted by a Hull cell test to obtain a bright copper plating layer. The pre-plating test in a Hull cell apparatus was performed to determine the power supply parameters when adjusting the solution parameters: forward current 2A, forward duty cycle 80%, forward cycle 10ms, reverse current 0.04A, reverse duty cycle 40%, reverse cycle 4 ms. Taking a phosphorus copper plate subjected to surface treatment as an anode and a stainless steel plate subjected to surface treatment as a cathode, and electroplating a bright copper coating by adopting a double-pulse electrodeposition process, wherein the electrodeposition time is 1h, and the stirring speed is as follows: 20-30 r/min, temperature: and (4) room temperature.

The experimental results show that the property difference of the obtained coating is large under the conditions of different solution parameters. All the plating pieces have different degrees of brightness, but most of the plating layers only have very small areas and low degrees of brightness, and other areas are not bright and have granular and uneven states. Scorching and blackening at the proximal end, cracks at the distal end part and poor overall effect. The plating piece prepared by the optimal plating solution has obvious near-end and far-end subareas, and has bright large piece and smooth surface. Most of the coating is very bright and flat, even reaching the brightness of the mirror surface.

The plating solution was determined to contain 200g/L copper sulfate, 60g/L concentrated sulfuric acid, 0.01g/L sodium polydithio-dipropyl sulfonate, 0.006g/L ethylene thiourea, 0.0005 g/L2-mercaptobenzimidazole, 0.04g/L polyethylene glycol and 0.03g/L chloride ion by Hull cell experiment.

In S30, in the operation of forming the copper plating layer on the surface of the cathode 10 by electroplating under the stirring condition, the electroplating temperature is room temperature, the electroplating time is 0.5 h-6 h, and the stirring speed is 20 r/min-30 r/min.

The following are specific examples.

Example 1

The surface treatment is carried out on the tin-bismuth alloy sheet, the tin-bismuth alloy sheet is sequentially subjected to 400-mesh, 800-mesh, 1200-mesh and 2000-mesh metallographic abrasive paper grinding → polishing → ultrasonic paraffin removal cleaning (the time is about 30 seconds, the surface of a workpiece is clean, the temperature is 80-95 ℃) → spraying water (the time is 10 seconds and 2 cylinders are 5 seconds) → electrolytic degreasing (1 minute to 2 minutes, the temperature is 42-45) → spraying water (the time is 5 seconds and 2 cylinders are 5 seconds) → activating acid etching (10 seconds to 15 seconds, the room temperature is 25-30) → spraying water (the time is 5 seconds and 4 cylinders are 10 seconds), and the surface treatment of the tin-bismuth alloy sheet is completed.

And (3) carrying out surface treatment on the two phosphorus copper plates, and sequentially grinding the phosphorus copper plates by using 800-mesh, 1200-mesh and 2000-mesh metallographic abrasive paper → polishing → spraying and rinsing (spraying for 5 seconds and rinsing for 4 cylinders for 10 seconds).

Referring to fig. 2, a surface-treated tin-bismuth alloy sheet is used as a cathode 10, two phosphor-copper plates are used as a first anode 20 and a second anode 30, respectively, the cathode 10, the first anode plate 20 and the second anode plate 30 are immersed in an electroplating solution, and the cathode 10, the first anode plate 20 and the second anode plate 30 are connected to a double pulse circuit. The electroplating solution comprises 200g/L of copper sulfate, 60g/L of concentrated sulfuric acid, 0.01g/L of sodium polydithio-dipropyl sulfonate, 0.006g/L of ethylene thiourea, 0.0005g/L of 2-mercaptobenzimidazole, 0.04g/L of polyethylene glycol and 0.03g/L of chloride ions.

Setting parameters of a double-pulse circuit, wherein the electrodeposition time is 1h, and the stirring speed is as follows: and electroplating at 25r/min at room temperature to form a copper coating on the surface of the cathode 10. The parameters of the double pulse circuit are set as follows: forward current density 5.0A/dm²The forward duty cycle is 55%, the reverse duty cycle is 15%, the forward period is 6ms, and the reverse period is 2.5 ms.

The tin-bismuth alloy sheet obtained in this example and having a copper plating layer electrodeposited was designated as a 1.

Example 2

The basic operation flow of embodiment 2 is the same as that of embodiment 1 except that the parameters of the double pulse circuit are set as follows: forward current density 2A/dm²The forward duty cycle is 50%, the reverse duty cycle is 20%, the forward period is 10ms, and the reverse period is 4 ms.

The tin-bismuth alloy sheet obtained in this example and having a copper plating layer electrodeposited was designated as a 2.

Example 3

The basic operation flow of embodiment 3 is the same as that of embodiment 1 except that the parameters of the double pulse circuit are set as follows: forward current density of 7A/dm²The forward duty cycle is 60%, the reverse duty cycle is 10%, the forward period is 4ms, and the reverse period is 1 ms.

The tin-bismuth alloy sheet obtained in this example and having a copper plating layer electrodeposited was designated as a 3.

Example 4

The basic operation flow of embodiment 4 is the same as that of embodiment 1 except that the parameters of the double pulse circuit are set as follows: forward current density 4A/dm²The forward duty cycle is 60%, the reverse duty cycle is 15%, the forward period is 10ms, and the reverse period is 1 ms.

The tin-bismuth alloy sheet obtained in this example and having a copper plating layer electrodeposited was designated as a 4.

Comparative example 1

The basic operation procedure of comparative example 1 is the same as that of example 1 except that electrodeposition is performed using a direct current power supply.

The tin bismuth alloy sheet electrodeposited with copper plating obtained in comparative example 1 was designated as b 1.

Comparative example 2

The basic operation procedure of comparative example 2 is the same as that of example 2 except that electrodeposition is performed using a direct current power supply.

The tin bismuth alloy sheet electrodeposited with copper plating obtained in comparative example 2 was designated as b 2.

Comparative example 3

The basic operation procedure of comparative example 3 is the same as that of example 3 except that electrodeposition is performed using a direct current power supply.

The tin bismuth alloy sheet electrodeposited with copper plating obtained in comparative example 3 was designated as b 3.

Comparative example 4

The basic operation procedure of comparative example 4 is the same as that of example 4 except that electrodeposition is performed using a direct current power supply.

The tin bismuth alloy sheet electrodeposited with copper plating obtained in comparative example 4 was designated as b 4.

Test example 1

The products prepared in examples 1 to 4 and comparative examples 1 to 4 were photographed and compared, respectively, to obtain fig. 4.

The grading reference standard of the visual brightness empirical evaluation method according to the visual brightness empirical evaluation method is as follows:

a. the surface of the first-level (bright mirror surface) plating layer is smooth like a mirror, so that the face, the five sense organs and the eyebrows can be clearly seen;

b. the surface of the second-level (bright) plating layer is flat and bright, so that the five sense organs and the face can be seen, but the picture is slightly weakened;

c. the whole three-level (semi-bright) plating layer has slight brightness and cannot clearly shine a profile;

d. the surface of the four-level (non-bright) plating layer is basically matt, and a face picture cannot be seen.

Referring to fig. 4, it can be seen that the brightness of the copper coatings prepared in examples 1 to 4 all reaches first-level brightness, while the brightness of the copper coatings prepared in comparative examples 1 to 4 all reaches second-level brightness, so that the copper coatings prepared in examples 1 to 4 have better brightness effect and better brightness than the copper coatings prepared in comparative examples 1 to 4.

It can be seen from fig. 4 that the copper coatings prepared in examples 1 to 4 have smooth surfaces and no burrs or pits, while the copper coatings prepared in comparative examples 1 to 4 have substantially flat surfaces but slight pits and slight cracks at the edges. It can be seen that the copper plating layers obtained in examples 1 to 4 had better flatness than those obtained in comparative examples 1 to 4.

Test example 2

The copper plating layers obtained in comparative example 1 and example 1 were observed under a metallographic microscope at 500 times magnification, respectively, to obtain fig. 5a and 5 b.

As can be seen from fig. 5a, the copper plating layer prepared in comparative example 1 has uneven surface, more pits and holes, and a part of small holes are connected to form larger pores, so that the surface of the plating layer is more mottled.

As can be seen from fig. 5b, the surface of the copper plating layer obtained in example 1 was still relatively uniform, fine and flat, and only a small number of very fine pores were observed, and the porosity was reduced, which was a very great improvement in uniformity and flatness compared to comparative example 1.

Test example 3

The copper plating layers obtained in example 1 and comparative example 1 were observed under a scanning electron microscope to obtain fig. 6a and 6 b.

As can be seen from fig. 6a, the copper plating layer prepared in comparative example 1 has a large amount of agglomerated particles on the surface, and a rough surface is formed, and many holes are formed, resulting in an uneven surface of the plating layer as a whole. This indicates that the plating solution has poor dispersion ability and the diffusion layer has an increased thickness under the action of the DC power supply.

As can be seen from fig. 6b, the copper plating layer prepared in example 1 has fine grains, is tightly arranged, has no obvious holes, and the surface of the formed plating layer has good uniformity and flatness.

Test example 4

The thickness of the cut surfaces of the copper plating layers obtained in example 1 and comparative example 1 was measured by a scanning electron microscope, and the results are shown in table 1.

Table 1: comparative table of thickness of copper plating layers obtained in example 1 and comparative example 1

	Thickness of	Deposition rate
			Comparative example 1	64.5μm	0.065mm/h
Example 1	68.2μm	0.068mm/h

As can be seen from table 1, the double pulse copper electroplating can improve current efficiency, thereby achieving a faster deposition rate and a thicker plating thickness.

In conclusion, the method for electrodepositing bright copper provided by the invention uses the double-pulse electrodeposition method to prepare the copper coating on the surface of the tin-bismuth alloy substrate, researches parameters of a double-pulse power supply in the double-pulse copper plating process, and compares the parameters with the copper coating obtained by direct current electroplating, and finds that the copper coating prepared by matching the double-pulse power supply with a novel plating solution is more delicate and smoother, can achieve a better bright effect, and greatly improves the uniformity, the effect of depositing the bright copper not only provides a good implantation for electrodeposited gold, but also simplifies the difficulty of post-process mold-holding sand blasting, can reduce scrapping to a great extent, improves the efficiency of the whole production process, and the goods with smooth bright surfaces even can reach the standard of jewelry wearing without polishing.

Compared with the direct current plating, the advantages of the double pulse plating mainly focus on the following four aspects:

(1) coating thickness and flatness: the plating thickness of the double-pulse current is uniformly distributed, and the reverse pulse can dissolve the protrusions or burrs on the cathode plating layer to enable the plating layer to be smoother.

(2) In the degree of crystal refinement: the alternative action of the forward pulse current and the reverse pulse current ensures that the growth speed of the crystal cannot catch up with the formation speed of crystal nuclei, and the number of the crystal nuclei electrodeposited on the cathode is obviously increased, thereby refining crystal grains, leading the surface of a plating layer to be more compact, and reducing the porosity of the plating layer.

(3) The plating layer has binding force: the periodic positive pulse current and the periodic negative pulse current enable the surface of the plated part to be in a surface activation state for a long time, so that organic impurities in the plating layer are reduced, hydrogen in the plating layer is oxidized, the occurrence of hydrogen embrittlement is reduced, the internal stress is reduced, and the plating layer with good binding force is obtained.

(4) Coating deposition rate: the deposition rate of the double pulse power supply is faster because the reverse pulse advantageously reduces the actual diffusion layer thickness of the cathode, thereby improving current efficiency.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A method of electrodepositing bright copper, comprising the steps of:

performing surface treatment on the core mold;

2. Method for the electrodeposition of bright copper according to claim 1, characterized in that the parameters of the double pulse circuit are set as follows: forward current density 2.0A/dm²～7.0A/dm²The forward duty ratio is 50-60%, the reverse duty ratio is 10-20%, the forward period is 4-10 ms, and the reverse period is 1-4 ms.

3. The method of electrodepositing bright copper according to claim 1, wherein the plating solution comprises 200g/L of copper sulfate, 60g/L of concentrated sulfuric acid, 0.01g/L of sodium polydithio-dipropyl sulfonate, 0.006g/L of ethylene thiourea, 0.0005g/L of 2-mercaptobenzimidazole, 0.04g/L of polyethylene glycol, and 0.03g/L of chloride ion.

4. The method for electrodepositing bright copper according to any one of claims 1 to 3, wherein in the step of electroplating the surface of the cathode under stirring to form the copper coating, the electroplating temperature is room temperature, the electroplating time is 0.5-6 h, and the stirring speed is 20-30 r/min.

5. The method of electrodepositing bright copper according to claim 1, wherein the first anode plate and the second anode plate are disposed opposite and spaced apart, and the cathode is disposed between the first anode plate and the second anode plate.

6. The method of electrodepositing bright copper according to claim 5, wherein the first anode plate and the second anode plate are both surface treated phosphor-copper plates.

7. Method for the electrodeposition of bright copper according to claim 5, characterized in that the surface treatment of the phosphor-copper plate is carried out as follows: and sequentially polishing 800 meshes of metallographic abrasive paper, 1200 meshes of metallographic abrasive paper and 2000 meshes of metallographic abrasive paper on the phosphorus copper plate, and spraying water to complete the surface treatment of the phosphorus copper plate.

8. The method of electrodepositing bright copper according to claim 1, wherein the operation of surface treating the mandrel: it is right in proper order the mandrel carries out 400 mesh metallographic abrasive paper and polishes, 800 mesh metallographic abrasive paper and polishes, 1200 mesh metallographic abrasive paper and polishes, 2000 mesh metallographic abrasive paper and polishes, polishing, ultrasonic cleaning, sprays for the first time and crosses water, electrolysis deoiling, sprays for the second time and crosses water, activation acid etching and sprays for the third time and cross water, accomplishes the surface treatment of mandrel.

9. The method of electrodepositing bright copper according to claim 8, wherein the ultrasonic cleaning is performed for a time of 20 to 40 seconds at a temperature of 80 to 95 ℃;

the time of electrolytic degreasing is 1 min-2 min, and the temperature is 42-45 ℃;

the time of the activation acid etching is 10-15 s, and the temperature is 25-30 ℃.

10. The method of electrodepositing bright copper according to claim 1, 8 or 9, wherein the mandrel is a tin bismuth alloy mandrel, wax sprayed silver oil or a low temperature alloy.