KR102313739B1 - Plating Solution Composition having Ruthenium and Method of plating using the same - Google Patents

Abstract

The present invention is an alloy plating solution composition containing ruthenium, comprising 3.0 to 5.0 parts by weight of potassium gold cyanide, 0.01 to 2.0 parts by weight of ruthenium sulfate, 50 to 80 parts by weight of citric acid, and 30 to 50 parts by weight of sulfamic acid.

Description

Alloy plating solution composition containing ruthenium and ruthenium plating method using the same

The present invention relates to an alloy plating solution composition containing ruthenium and a ruthenium plating method using the same.

Ruthenium (Ru: Ruthenium) is a chemical element with an atomic number of 44, a rare transition metal belonging to the platinum group, produced together from platinum ore, and used as a catalyst in platinum alloys.

Ruthenium is also used as a curing agent for other platinum group elements, especially platinum or palladium, and powder or colloid is used as a catalyst for various purposes. Palladium 4.5% ruthenium alloy is used for decoration, and platinum 10% ruthenium alloy is used for decoration or electrical contact material.

In the case of the plating field, it is known to use a ruthenium complex salt, ruthenium chloride, and ruthenium sulfate as a ruthenium plating solution.

These mainly use a platinum-plated titanium (Ti) plate as the anode and the object to be plated as the cathode, immersing them in the plating solution and energizing them to deposit a plating film on the cathode.

Ruthenium plating can plated a specimen with ruthenium, which has better reflectivity than conventional nickel plating, and obtains a black color. In addition, since ruthenium, which does not cause a chemical reaction with the human body and other precious metals, is used as a plating material, there is an advantage that it does not adversely affect the human body and precious metals such as gold.

Accordingly, as in Korean Patent Application Laid-Open No. 10-2002-0045934, there was an attempt to use ruthenium for plating in the prior art, but there was a problem in that it was not possible to accurately control the plating color change according to the amount of any ruthenium used.

(Document 1) Korean Patent Application Laid-Open No. 10-2002-0045934 (June 20, 2002)

The alloy plating solution composition containing ruthenium and the ruthenium plating method using the same according to the present invention have the following problems.

First, it is intended to control the composition and content having excellent plating effect.

Second, it is intended to control the change of plating color according to the content of ruthenium.

Third, we would like to present a plating method using ruthenium.

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

The present invention is an alloy plating solution composition containing ruthenium, comprising 3.0 to 5.0 parts by weight of potassium gold cyanide, 0.01 to 2.0 parts by weight of ruthenium sulfate, 50 to 80 parts by weight of citric acid and 30 to 50 parts by weight of sulfamic acid, wherein the ruthenium sulfate is At least one of the first composition condition in which 0.01 part by weight or more and less than 1.0 part by weight is contained or the second composition condition in which the ruthenium sulfate is contained in an amount of 1.0 part by weight or more to 2.0 parts by weight or less is provided, the first composition condition and the second composition condition is characterized in that the plated surface is implemented in a brown color, and the first composition condition is implemented in a light brown color than the second composition condition.

In the present invention, it is more preferable that the amount of ruthenium sulfate in the first composition condition is 0.5 parts by weight.

In the present invention, the amount of ruthenium sulfate in the second composition condition is more preferably 1.5 parts by weight.

The present invention is a ruthenium plating method, S1 step of preparing an alloy plating solution provided with the composition according to the present invention; S2 step of inserting the object to be plated into the alloy plating solution; And by heating and energizing the alloy plating solution, it may include a step S3 of plating ruthenium on the surface of the body to be plated.

In the present invention, the voltage of the step S3 is 2-4 V, the pH is 3.6-4.0, and the temperature is preferably 55±5°C.

In the present invention, the voltage of the step S3 is 3 V, the pH is 3.8, and the temperature is more preferably 55 ℃.

The alloy plating solution composition containing ruthenium and the ruthenium plating method using the same according to the present invention have the following effects.

First, ruthenium sulfate is selected, and gold potassium cyanide is selected so that the plating effect is excellent.

Second, there is an effect of controlling the plating color to brown and dark brown according to the content of ruthenium.

Third, there is an effect that enables efficient ruthenium plating by controlling the voltage, pH, and temperature of the plating process.

Effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a process flowchart of a ruthenium plating method according to the present invention.
2A and 2B are plated objects manufactured by the ruthenium plating method according to the present invention, and FIG. 2C is a copper specimen before plating.
3 is a surface morphology of Au-Ru alloy plating according to the ruthenium component.
Figure 4 is the surface EDS of Au-Ru alloy plating using ruthenium chloride, Figures 5 and 6 shows the surface roughness AFM analysis of the Au-Ru alloy layer using ruthenium chloride.
7 is a surface EDS of Au-Ru alloy plating using ruthenium sulfate according to the present invention, and FIGS. 8 and 9 show the results of AFM analysis of the surface roughness of the Au-Ru alloy layer using ruthenium sulfate.

Hereinafter, with reference to the accompanying drawings, an embodiment of the present invention will be described so that those of ordinary skill in the art can easily carry out the present invention. As can be easily understood by those of ordinary skill in the art to which the present invention pertains, the embodiments described below may be modified in various forms without departing from the concept and scope of the present invention. Wherever possible, identical or similar parts are denoted by the same reference numerals in the drawings.

The terminology used herein is for the purpose of referring to specific embodiments only, and is not intended to limit the invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite.

The meaning of "comprising," as used herein, specifies a particular characteristic, region, integer, step, operation, element and/or component, and other specific characteristic, region, integer, step, operation, element, component, and/or component. It does not exclude the presence or addition of groups.

All terms including technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms defined in the dictionary are further interpreted as having a meaning consistent with the related art literature and the presently disclosed content, and unless defined, are not interpreted in an ideal or very formal meaning.

The present invention is a color gold alloy plating technology for imparting high added value through plating in decorative accessories and the like. By using platinum group precious metal elements, it is to deviate from the traditional gold color and to realize various colors.

To this end, the present invention is characterized in that it is possible to control the color of gold plating by adding ruthenium and other metal elements.

The present invention relates to an alloy plating solution composition containing ruthenium and a ruthenium plating method using the alloy plating solution.

First, an alloy plating solution composition containing ruthenium will be described.

The alloy plating solution composition according to the present invention preferably contains 3.0 to 5.0 parts by weight of potassium gold cyanide, 0.01 to 2.0 parts by weight of ruthenium sulfate, 50 to 80 parts by weight of citric acid, and 30 to 50 parts by weight of sulfamic acid.

In the present invention, gold (Au) may be contained in an amount of 3.0 to 5.0 parts by weight as a _{gold potassium cyanide (KAu(CN) 2 ) metal salt.}

Gold potassium cyanide is used as a source of ^{gold ions (Au +} ) required for gold (Au) plating. The theoretical content of gold is known to be 68.3%. Gold adds added value to precious metals and is also a necessary ingredient to obtain the desired brown color. When the amount of gold potassium cyanide is less than 3.0 parts by weight, a desired color is not realized during plating, and there is a problem in that the plating speed is slowed down. When the amount of gold potassium cyanide exceeds 5.0 parts by weight, excessive plating vacancies may occur and rough plating may occur, and there is a problem in that the color is not easy to implement. Therefore, it is preferable to contain 3.0-5.0 weight part of gold-potassium cyanide.

In the present invention, ruthenium is ruthenium sulfate (Ru(SO4) ₂ ) It may contain 0.01 to 2.0 parts by weight as a metal salt.

In the case of the plating field, ruthenium complex salt and ruthenium chloride are mainly used as the ruthenium plating solution, but ruthenium sulfate was used in the present invention.

Ruthenium plating can plated a specimen with ruthenium, which has better reflectivity than conventional nickel plating, and obtains a black color. In addition, since ruthenium, which does not cause a chemical reaction with the human body and other precious metals, is used as a plating material, there is an advantage that it does not adversely affect the human body and precious metals such as gold.

In addition, even if a small amount of ruthenium is added, there is an effect of refining and densifying the crystal grains of the alloy. Through this, corrosion resistance and wear resistance of the alloy plating can be improved.

If the content of ruthenium sulfate (Ru(SO4) ₂ ) is less than 0.01 parts by weight, there is a disadvantage that the color of the plating to be implemented in the present invention cannot be obtained. When it exceeds 2.0 parts by weight, electricity passes through the object (product) to be plated due to the nature of the electroplating, which causes a defect in the low current partial plating, and there are disadvantages in that a double color or non-plating occurs. Therefore, it is preferable that 0.01 to 2.0 parts by weight is contained.

On the other hand, in general, since the liquid voltage of an electroplating bath is low when the specific conductivity is low, the specific conductivity can be made high by adding an electrically conductive salt. When a conductive salt is added, the coating power and spreadability of the plating bath are improved, and it also functions as a pH buffer.

The alloy plating solution composition according to the present invention may further include a conductive salt in order to maintain the pH of the plating solution and impart electrical conductivity.

As the conductive salt according to the present invention, it is preferable to contain 50-80 parts by weight of citric acid. Citric acid plays a role in maintaining the pH of the plating solution. Citric acid is used as a conductive salt, and in the electroplating bath, if the specific conductivity is low, the liquid voltage increases, so add conductive salt to increase the specific conductivity. It improves the coating power and spreadability of the plating bath, and in some cases also serves as a pH buffer. If the citric acid is less than 50 parts by weight, there is a problem that non-plating phenomenon may occur in the low current portion. When the citric acid exceeds 80 parts by weight, the specific conductivity is too high, and there is a problem in that a double color is generated due to abnormal vacancy of the plating. Therefore, it is preferable that 50-80 parts by weight of citric acid is contained.

As the conductive salt according to the present invention, it is preferable to contain 30 to 50 parts by weight of sulfamic acid. Sulfamic acid suppresses the instability of ruthenium ions during electrolysis, prevents the formation of low-valent ruthenium that is not metallized, and enables stable ruthenium plating. When the amount of sulfamic acid is less than 30 parts by weight, ruthenium having a low valence is generated and there is a problem in that the plating is abnormal. When the amount of sulfamic acid exceeds 50 parts by weight, there is a problem in that the plating is peeled off due to poor adhesion of the plating. thus. It is preferable that 30-50 weight part of sulfamic acid is contained.

On the other hand, in the case of ruthenium, it is possible to implement a light gray color to a dark black color depending on the content. In the present invention, a light brown color and a dark brown color surface treatment is possible through a stable reaction between the main gold (Au) plating solution and lutein. By using the yellow color of gold (Au) and the gray or black color of ruthenium (Ru), a light brown or dark brown surface treatment close to black is possible.

As an example for obtaining a light brown color, ruthenium sulfate according to the present invention is preferably contained in an amount of 0.01 parts by weight or more to less than 1.0 parts by weight, more preferably 0.5 parts by weight.

As an embodiment for obtaining a dark brown color, the ruthenium sulfate according to the present invention is preferably contained in an amount of 1.0 parts by weight or more to 2.0 parts by weight or less, more preferably 1.5 parts by weight.

Next, a ruthenium plating method using an alloy plating solution containing ruthenium will be described.

The ruthenium plating method according to the present invention includes the S1 step of preparing a ruthenium alloy plating solution provided with the composition and content according to the present invention; S2 step of inserting the object to be plated into the alloy plating solution; and a step S3 of plating the ruthenium on the surface of the body to be plated by heating and energizing the alloy plating solution.

The object to be plated used in this plating method can be made of various materials.

In step S1 according to the present invention, the ruthenium salt is dissolved after complete dissolution to prevent agitation and precipitation of the plating solution. At this time, in the present invention, alloy plating is performed using _{ruthenium (II) sulfate: O 12} Ru _{2 S).}

In step S3 according to the present invention, the voltage range is 2-4 V, the pH range is 3.6-4.0, and the temperature range is preferably 55±5°C. Further, it is more preferable that the voltage is 3 V, the pH is 3.8, and the temperature is 55°C.

Hereinafter, a plating result of a specimen plated with ruthenium using the alloy plating solution according to the present invention will be examined. 3 is a surface morphology of Au-Ru alloy plating according to the ruthenium component.

The specimens to be plated used in the analysis of the results were prepared with the following composition, content and process conditions.

2A and 2B are plated objects manufactured by the ruthenium plating method according to the present invention, and FIG. 2C is a copper specimen before plating. The plating color is changed according to the composition alloy material and content, especially the content of ruthenium. The results of ruthenium chloride used in general and ruthenium sulfate used in the present invention were compared.

The data used in this test example are as follows. Table 1 below is the data used for specimen preparation using ruthenium sulfate, and Table 2 below is the data used for specimen preparation using ruthenium chloride.

No. ingredient dry bath concentration
(g/L) range of use
(g/L) role One (KAu(CN) ₂ )
Gold Potassium Cyanide 3.0
(with metal) 3.0~5.0
(with metal) metal salt 2 Ru(SO ₄ ) ₂
ruthenium sulfate 0.5
(with metal) 0.01~2.0
(with metal) metal salt 3 C ₆ H ₈ O ₇ H ₂ O
citric acid 60 50-80 conductionitis 4 H ₃ NSO ₃
sulfamic acid 40 30-50 conductionitis 5 Voltage 3V 2~4V 6 pH 3.8 3.6 ~ 4.0 7 Temperature 55℃ 55 ± 5℃

No. ingredient dry bath concentration
(g/L) range of use
(g/L) role One (KAu(CN) ₂ )
Gold Potassium Cyanide 3.0
(with metal) 3.0~5.0
(with metal) metal salt 2 RuCl ₂
ruthenium chloride 0.5
(with metal) 0.01~1.0
(with metal) metal salt 3 C ₆ H ₈ O ₇ H ₂ O
citric acid 60 50-80 conductionitis 4 H ₃ NSO ₃
sulfamic acid 40 30-50 conductionitis 5 Voltage 3V 2~4V 6 pH 3.8 3.6 ~ 4.0 7 Temperature 55℃ 55 ± 5℃

3 is a surface morphology of Au-Ru alloy plating according to the ruthenium component.

In the case of the surface of the Au-Ru alloy plating layer using ruthenium chloride, it can be confirmed that the rough plating is made and pinholes and pits are partially generated. This is due to the failure to completely remove the plating layer due to rapid hydrogen generation in the plating solution during the plating process.

In case of Au-Ru alloy plating layer surface using ruthenium sulfate. You can check that the surface is clean. If it is checked at a high magnification of 5000 times or more, it can be confirmed that the particles are formed. Through this, it can be seen that a uniform growth rate was exhibited during plating.

Figure 4 is the surface EDS of Au-Ru alloy plating using ruthenium chloride, Figures 5 and 6 shows the surface roughness AFM analysis of the Au-Ru alloy layer using ruthenium chloride. 7 is a surface EDS of Au-Ru alloy plating using ruthenium sulfate according to the present invention, and FIGS. 8 and 9 show the results of AFM analysis of the surface roughness of the Au-Ru alloy layer using ruthenium sulfate.

Through Energy Dispersive Spectrometry (EDS), it can be confirmed that both the alloy plating layer using ruthenium chloride and the alloy plating layer using ruthenium sulfate form Au-Ru.

In the case of the Au-Ru alloy layer using ruthenium chloride, the Ra value is 14.486 nm, and in the case of the Au-Ru alloy layer using ruthenium sulfate, the Ra value is 7.696 nm. As confirmed from the surface morphology through the SEM of FIG. 3 , it is found to be related to the formation of fine particles.

Here, arithmetical average roughness (Ra) is a notation indicating the surface roughness and means the center line surface roughness. The higher the Ra value of the plating layer, the rougher the surface is, and the lower the Ra value of the plating layer, the smoother, the lower the Ra value is. However, since the Ra value of the specimen using ruthenium chloride is 14.486 nm, while the Ra value of the specimen using ruthenium sulfate is 7.696 nm, it can be seen that the surface of the specimen using ruthenium sulfate is smoother than that of the specimen using ruthenium chloride. can

The embodiments described in this specification and the accompanying drawings are merely illustrative of some of the technical ideas included in the present invention. Therefore, since the embodiments disclosed in the present specification are for explanation rather than limiting the technical spirit of the present invention, it is obvious that the scope of the technical spirit of the present invention is not limited by these embodiments. Modifications and specific embodiments that can be easily inferred by those skilled in the art within the scope of the technical idea included in the specification and drawings of the present invention should be interpreted as being included in the scope of the present invention.

Claims (8)

3.0 to 5.0 parts by weight of gold potassium cyanide, 0.01 to 2.0 parts by weight of ruthenium sulfate, 50-80 parts by weight of citric acid and 30-50 parts by weight of sulfamic acid,
At least one of a first composition condition in which the ruthenium sulfate is contained in an amount of 0.01 parts by weight or more to less than 1.0 parts by weight or a second composition condition in which the ruthenium sulfate is contained in an amount of 1.0 parts by weight or more to 2.0 parts by weight or less is provided;
In the first composition condition and the second composition condition, the plated surface is implemented in a brown color,
An alloy plating solution composition containing ruthenium, characterized in that the first composition condition is implemented in a light brown color than the second composition condition. delete The method according to claim 1,
An alloy plating solution composition containing ruthenium, characterized in that 0.5 parts by weight of ruthenium sulfate in the first composition condition. delete The method according to claim 1,
In the second composition condition, the ruthenium sulfate is an alloy plating solution composition containing ruthenium, characterized in that 1.5 parts by weight. S1 step of preparing an alloy plating solution provided with the composition according to claim 1;
S2 step of inserting the object to be plated into the alloy plating solution; and
and heating and energizing the alloy plating solution to plate ruthenium on the surface of the body to be plated. 7. The method of claim 6,
The voltage of the step S3 is 2 to 4 V, the pH is 3.6 to 4.0, and the temperature is 55±5° C. The ruthenium plating method. 8. The method of claim 7,
The voltage of the step S3 is 3 V, the pH is 3.8, and the ruthenium plating method, characterized in that the temperature is 55 ℃.

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