• Journal of Electrochemical Science and Technology
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• v.10 no.4
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• pp.408-415
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• 2019

Electroplating is a widely used surface treatment method in the manufacturing process of electronic parts and uniformity of the electrodeposition thickness is very crucial for these applications. Since many variables including fluid flow influence the uniformity of the film, it is difficult to conduct efficient research only by experiments. So many studies using simulation have been carried out. However, the most popular simulation technique, which calculates secondary current distribution, has a limitation on the considering the effects of fluid flow on the deposition behavior. And modified method, which is calculating a tertiary current distribution, is limited to a two-dimensional study of simple shapes because of the massive computational load. In the present study, we propose a new electroplating simulation method that can be applied to complex shapes considering the effect of flow. This new model calculates the electroplating process with three steps. First, the thickness of boundary layers on the surface of the cathode plane and velocity magnitudes at the positions are calculated from the simulation of fluid flow. Next, polarization curves of different velocities are obtained by calculations or experiments. Finally, both results are incorporated into the electroplating simulation program as boundary conditions at the cathode plane. The results of the model showed good agreements with the experimental results, and the effects of fluid flow of electrolytes on the uniformity of deposition thickness was quantitatively predicted.

• 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.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.3
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• pp.246-261
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• 2002

The screw loosening is one of the complications that happen frequently in dental implant prostheses. The purpose of this study was to evaluate the changes of reverse/loosening (opening) torque of the screw according to the surface modifications by sandblasting and 24K gold electroplating as well as to determine the possibility of the clinical use of a washer in dental implant. The reverse torque of 4 experimental conditions(control, sandblasted, use of washers, electroplasted) was measured by digital torque gauge (Model MGT50Z, Mark-10 Corp., 458 West John Street Hicksville, NY 11801 USA). Electronic torque controller (Nobel Biocare DEA 020) was used in fastening the gold screws into abutment replicas. Mixed Linear Model Analysis method was used for statistical analysis. To examine the changes of screw thread surface, microphotographs were taken by Olympus PME-3 metallurgic microscope (Olympus Optical Co. Ltd., Tokyo, Japan). Within the limitations of this study, the following results were drawn: 1. The surface modifications of the gold screws and the use of a washer have significantly affected the reverse torque value compared to the control group (P<0.01). 2. Sandblasting and electroplating treatments demonstrated significantly higher reverse torque value than that of control group. 3. The use of a washer may be one of the useful clinical methods that prevent the screw loosening. However, further studies are necessary for the material selection and design of the washer.

• Journal of the Korean Electrochemical Society
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• v.12 no.4
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• pp.317-323
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• 2009

Theoretical calculations for the secondary current distributions for the electrode with a projection part in electroplating were performed. Two kinds of electrodes were considered. One is a electrode with the overall conducting surfaces(Case 1) and the other is an electrode in which only a projection part has a conducting surface(Case 2). The effects of applied potential, the ratio of ion exchange current to conductivity, $\xi$ and the aspect ratio on the current distribution were examined. The increase of applied current or the value of $\xi$ decreased the uniformity of current distribution. The small value of aspect ratio resulted the more uniform current distribution and Case 2 showed the better uniformity than Case 2. When this model was applied into an electrode with various projection parts, the local current distribution along the electrode surface were obtained successfully. In this case, the decrease of $\xi$ also increase the uniformity of current distribution as seen previously.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.5
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• pp.247-251
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• 2004

We report highly improved yield strength of nickel thin film, prepared using electroplating. The micro-scaled nickel cantilever is found to have significantly higher yield strength than bulk nickel. For the yield strength test, the heights of the micro-scaled cantilever were varied up to 60 ${\mu}{\textrm}{m}$ and electrostatic force was used for actuation. Stress of the bent cantilever was estimated using the FEM large deflection model. The yield strength of the thin nickel film is found to be over five times higher than that of the bulk nickel previously published. Results from this study indicate that metal microstructures can be used for MEMS applications requiring large deflection.

• Journal of the Korean institute of surface engineering
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• v.43 no.6
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• pp.255-259
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• 2010

In this work, Ni-Co composites incorporated with nano-sized SiC particles in the range of 45-55 nm are prepared by electroplating. The effects of plating duration on the chemical composition, surface morphology, crystalline structures and hardness have been studied. The maximum hardness of Ni-Co-SiC composite coating is approximately 633 Hv at plating duration of 1 h. The hardness is gradually decreased with increasing plating duration, which can be attributed to the growth of crystalline size and the agglomerates of SiC nano-particles. It is therefore explained that the grain refinement of Ni-Co matrix and stable dispersion of SiC particles play an important role for strengthening, which indicate Hall-Petch relation and Orowan model were dominant for hardening of Ni-Co-SiC composite coatings.

• Journal of the Korean institute of surface engineering
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• v.28 no.3
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• pp.164-173
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• 1995

Based on the potential-theory model for secondary current distribution, we could predict the thickness distributions of electroplating on patterned substrates with the different size of the auxiliary electrode. The substrates contain lithographic patterns at each sample geometry. Each sample geometry had different current distribution at the same condition except the size of the auxiliary electrodes. The size effect of the auxiliary electrode on thickness distribution of electrodeposition on patterned electrode was investigated in a series of experiments. Copper was galvanostatically deposited from an acid-sulfate solution in a reciprocating paddle cell. The thickness distributions of the workpiece scale measured by profilometry across the specimen were in good agreement with the current distribution predicted by boundary element method.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.137-137
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• 2010

Copper electroplating is a very popular and important technology for depositing high-quality conductor interconnections, especially in through silicon via (TSV). As this advanced packaging technique developing, a mass of copper and chemical solution are used, so attention to these chemical materials into the utilization and costs can not be ignored. An economical and practical real-time chemical solution monitoring has not been achieved yet. Either Red-green-blue (RGB) or optical emission spectroscopy (OES) color sensor can successfully monitor the color condition of solution during the process. The reaction rate, uniformity and quality can map onto the color changing. Hidden Semi Markov model (HSMM) can establish mapping from the color change to upper indicators, and artificial neural network (ANN) can be integrated to comprehensively determine its targets, whether the solution inside the container can continue to use.

• Corrosion Science and Technology
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• v.21 no.2
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• pp.121-129
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• 2022

A study on water-based epoxy coated on mild steel using the electroplating method was conducted to optimize the process parameters for dry film thickness to achieve superior paint quality at optimal cost in an automotive plant. The regression model was used to adjust various parameters such as electrode voltage, bath temperature, processing time, non-volatile matter, and surface area to optimize the dry film thickness. The average dry film thickness computed using the model was in the range of 15 - 35 ㎛. The error in the computed dry film thickness with reference to the experimentally measured dry film thickness value was - 0.5809%, which was well within the acceptable limits of all paint shop standards. Our study showed that the dry film thickness on mild steel was more sensitive to electrode voltage and bath temperature than processing time. Further, the presence of non-volatile matter was found to have the maximum impact on dry film thickness.

• Journal of the Korean institute of surface engineering
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• v.28 no.5
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• pp.309-319
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• 1995

The substrate patterned with the dry film has the cavity which has the $90^{\circ}$ wall angle. Electroplating Cu on this patterned substrate has the differrent shape history with the electrochemical parameters. By potential theory model, the reason of the variation of the shape change with the these parameters was investigated. The shape history could be explained by the current flow and the correlated area effects. By embedding the Ni layer between the Cu layers, shape history with the time was obtained experimentally and the results was compared with the numerical analysis by BEM. The adhesive Cr-Cu film in TAB application was etched with the various condition. The best condition for the etchant of the Cr-Cu film was found.