• Journal of Power System Engineering
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• v.10 no.3
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• pp.58-66
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• 2006

The effect of bath composition, plating condition and plating rate on the magnetic properties of electroless Ni-Cu-P deposits were investigated. With increasing $CuSO_4$ concentration in the bath, plating rate increased, while the Br value of deposits decreased Sharply. Plating rate increased up to 34% with the addition of 200ppm of NaF and 0.8ppm of Thiourea to the bath. Plating reaction had been ceased by the increase of pH above 11.3, bath temperature higher than $90^{\circ}C$ and under $70^{\circ}C$. The Br value of deposit was uniform with various concentration of complexing agent (Sodium citrate, Ethylenediamine) in the bath. The Br value of deposit was almost equal to that found by the addition of stabilizer(Thiourea) and accelerator(NaF). The Br value of deposit was uniform in plating time(120 min) and heat treatment temperature(below $200^{\circ}C$), and were confirmed to have adequate bath stability for practical use.

• Journal of the Korean institute of surface engineering
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• v.50 no.4
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• pp.244-250
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• 2017

Effects of plating conditions (dispersant concentration, plating time, and ultrasonication) on electroless Cu plating on SiC fabric woven by crossing of SiC continuous fibers vertically were studied. The ultrasonic dispersion treatment not only did not improve the dispersion of the SiC fibers, but also did not change the plating thickness. The ultrasonication in the pretreatment step of electroless plating did not improve the dispersion of the fibers, while the ultrasonication in the plating step enhanced the dispersion of the fibers and decreased the thickness of the Cu films. It was possible to control the thickness of the Cu coating layer as well as the dispersion of the fibers in the fabric by changing the plating conditions such as dispersant concentration, plating time, and ultrasonication, but it was very difficult to coat copper on the intersection of vertical fibers in the fabric.

• Journal of the Korean institute of surface engineering
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• v.55 no.2
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• pp.120-132
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• 2022

In the non-cyanide-based electroless Au plating solution using thiomalic acid as a complexing agent and aminoethanethiol as a reducing agent, analysis of each component constituting the plating solution is essential for the analysis of the reaction mechanism. And component analysis in the plating solution is important for monitoring component changes in the plating process and optimizing the management method. Capillary Electrophoresis (CE) method is rapid, sensitive and quantitative and could be readily applied to analysis of Auⁿ⁺ ion, complexing agent and reducing agent in electroless Au plating solution. In this study, the capillary electrophoresis method was used to analyze each component in the electroless Au plating solution in order to elucidate the complex bonding form and the plating mechanism of the non-cyanide-based electroless Au plating bath. The purpose of this study was to establish data for optimizing the monitoring and management method of plating solution components to improve the uniformity of precipitation and stability. As a result, it was confirmed that the analysis of thiomalic acid as a complexing agent and Auⁿ⁺ ions and the analysis of aminoethanethiol as a reducing agent were possible by capillary electrophoresis. In the newly developed non-cyanide-based electroless Au plating solution, it was confirmed that Auⁿ⁺ ions exist in the form of Au⁺ having a charge of +1, and that thiomalic acid and Au⁺ are combined in a molar ratio of 2 : 1. In addition, it was confirmed that aminoethanethiol can form a complex by combining with Au⁺ ions depending on conditions as well as acting as a reducing agent.

• Polymer(Korea)
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• v.31 no.3
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• pp.184-188
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• 2007

Monodisperse PMMA/HDDA polymer particles were coated via electroless Ni plating using sodium hypophosphite as a reducing agent in an acidic environment. In this study, the effects of 1) the pretreatment conditions, 2) the plating temperature, 3) the plating pH, and 4) the initial pH, control of plating bath on the variation of plating rate, surface state of plated particles and plating reproducibility were investigated. It was observed that every pretreatment steps, especially conditioning and acceleration step, were very important for obtaining uniform Ni plating and the plating rate was increased with the increase of plating temperature and pH. Moreover, the initial pH control of plating bath was critical for the plating reproducibility.

• Journal of Power System Engineering
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• v.8 no.3
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• pp.36-43
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• 2004

The effect of bath composition, plating condition and plating rate on the magnetic property of electroless Co-Cu-P deposits were investigated. With increasing $CuCl_2$ concentration in the bath, plating rate increased, while the Br value of deposit decreased sharply. Deposited surface were inferiority by the increase pH above 10.5, bath temperature higher than $80^{\circ}C$. Plating reaction had been ceased by the increase of pH above 11, bath temperature higher than $90^{\circ}C$ and under $40^{\circ}C$. The Br value of deposit was uniform with various concentration of complexing agent(sodium citrate) in the bath. The Br value of deposit was almost equal to that found by the addition of stabilizer (thiourea) and accelerator(NaF). The Br value of deposit was uniform in plating time(20min) and heat treatment temperature(below $200^{\circ}C$), and were confirmed to have adequate bath stability for practical use.

• Corrosion Science and Technology
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• v.18 no.4
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• pp.148-153
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• 2019

Pure nickel with a thickness of 1 mm was plated on type 304 stainless steels and low alloy steels (JIS G3131 SPHC) by electrolytic plating method in a circulating plating bath. Plating performance, mechanical properties, and surface characteristics were evaluated in terms of pretreatment process, anode material, pH, current density, and flow rate of the plating solution. Addition of hydrochloric acid during pre-treatment process improved the adhesion performance of plating. To improve plating efficiency, it is desirable to use S-nickel rather than electrolytic nickel. The use of S-nickel was also confirmed to be desirable for maintaining the pH and concentration of the plated solution. The defect of the plating using S-nickel anode produced pit on the surface. However, it is believed that proper control can be obtained by increasing the flow rate. Internal stress and hardness values of electrolytic nickel plating according to current density need to be carried out with further studies.

• Journal of the Korean institute of surface engineering
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• v.21 no.1
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• pp.19-27
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• 1988

The principe and practice of pulse plating, and prospect in the future on pulse plating are reviewed. Some of the advantages of pulse pulse plating are detailed as compared with DC plating. The advantages of pulse plating are summarized as follows: 1)smooth and fine grained deposits 2) reduction in hydrogen embrittlement of deposits 3) reduction of residual stress and microcracks in the deposit 4) improvement of physical properties 5) uniform alloy composition through the deposit thinkness 6) improved thrower and adhesion.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.3
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• pp.1-7
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• 2012

Electroplating technology is widely used in semiconductor microelectronic industry. With the development of semiconductor integrated circuit to high density and light-small scale, Extremely high quality and plated uniformity of the deposited metals are needed. Simulation technique can help to obtain better plating results. Although a few plating simulation softwares have been commercialized, plating simulation is not widely prevalent in Korea. In this paper, principle of electroplating and mathematical modeling of plating simulation are discussed. Also introduced are some cases enhancing plating thickness uniformity on leadframe, PCB and wafer by using plating simulation.

• Journal of the Korean institute of surface engineering
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• v.44 no.1
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• pp.1-6
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• 2011

A NiW functional alloy plating was investigated as variables of metal ion concentration, complexing agent, temperature, pH and applied current density. Even if numerous studies on reaction mechanism of NiW induced codeposition were carried out during couples of decade, it has not been acceptable reaction mechanism. This study was focused on the effect of the plating variables on the alloy composition in the NiW alloy plating. Applied current density could control mainly the alloy composition rather than other plating variables. It has also been confirmed that the functional alloy plating such as layered or gradient plating was possible by controlling applied current density.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.10a
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• pp.15-15
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• 1999

In chip plating, several parameters must be taken into consideration. Current density, solution concentration, pH, solution temperature, components volume, chip and media ratio, barrel geometrical shape were most likely found to have an effect to the process yields. The 3 types of barrels utilized in chip plating industry are the conventional rotating barrel. vibrational barrel (vibarrel), and the centrifugal type. Conventional rotating barrel is a close type and is commonly used. The components inside the barrel are circulated by the barrel's rotation at a horizontal axis. Process yield has known to have higher thickness deviation. The vibrational barrel is an open type which offers a wide exposure to electrolyte resulting to a stable thickness deviation. It rotates in a vertical axis coupled with multi-vibration action to facilitate mixed up and easy transportation of components, The centrifugal barrel has its plated work centrifugally compacted against the cathode ring for superior electrical contact with simultaneous rotary motion. This experiment has determined the effect of barrel vibration intensity to the plating thickness distribution. The procedures carried out in the experiment involved the overall plating process., cleaning, rinse, Nickel plating, Tin-Lead plating. Plating time was adjusted to meet the required specification. All other parameters were maintained constant. Two trials were performed to confirm the consistency of the result. The thickness data of the experiment conducted showed that the average mean value obtained from higher vibrational intensity is nearer to the standard mean. The distribution curve shown has a narrower specification limits and it has a reduced variation around the target value, Generally, intensity control in vi-barrel facilitates mixed up and easy transportation of components, However, it is desirable to maintain an optimum vibration intensity to prevent solution intrusion into the chips' internal electrode. A cathodic reaction can occur in the interface of the external and internal electrode. $2HD{\;}+{\;}e{\;}{\rightarrow}20H{\;}+{\;}H_2$ Hydrogen can penetrate into the body and create pressure which can cause cracks. At high intensity, the chip's motion becomes stronger, its contact between each other is delayed and so plating action is being controlled. However, the strong impact created by its collision can damage the external electrode's structure thereby resulting to bad plating condition. 1 lot of chip was divided into two equal partion. Each portion was loaded to the same barrel one after the other. Nickel plating and tin-lead plating was performed in the same station. Portion A maintained the normal barrel vibration intensity and portion B vibration intensity was increased two steps higher. All other parameters, current, solution condition were maintained constant. Generally, plating method find procedures were carried out in a best way to maintained the best plating condition. After plating, samples were taken out from each portion. molded and polished. Plating thickness was investigated for both. To check consistency of results. 2nd trial was done now using different lot of another characteristics.