• Journal of the Korean Electrochemical Society
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• v.10 no.1
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• pp.14-19
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• 2007

The corrosion and passivation of copper was investigated with the copper rotating disk electrode(Cu-RDE) in borate buffer solution. It has been observed with the mixed potential theory that the corrosion potential for the rotation rate increase under the convective diffusion condition was increased. It was suggested that the chemical intermediates and product 13. the copper oxidation were $Cu(OH)_{ads},\;{Cu(OH)_2}^-,\;Cu_2O,\;Cu(OH)_2,\;and\;CuO$.

• Korean Journal of Materials Research
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• v.20 no.10
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• pp.555-558
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• 2010

This study examined the effect of current density on the surface morphology and physical properties of copper plated on a polyimide (PI) film. The morphology, crystal structure, and electric characteristics of the electrodeposited copper foil were examined by scanning electron microscopy, X-ray diffraction, and a four-point probe, respectively. The surface roughness, crystal growth orientation and resistivity was controlled using current density. Large particles were observed on the surface of the copper layer electroplated onto a current density of 25 mA/$cm^2$. However, a uniform surface and lower resistivity were obtained with a current density of 10 mA/$cm^2$. One of the important properties of FCCL is the flexibility of the copper foil. High flexibility of FCCL was obtained at a low current density rather than a high current density. Moreover, a reasonable current density is 20 mA/$cm^2$ considering the productivity and mechanical properties of copper foil.

• Korean Journal of Materials Research
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• v.30 no.1
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• pp.44-49
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• 2020

The effect of intercritical annealing temperature on the microstructure and mechanical properties of Fe-9Mn-0.2C-3Al-0.5Si medium manganese steels containing Cu and Ni is investigated in this study. Six kinds of medium manganese steels are fabricated by varying the chemical composition and intercritical annealing temperature. Hardness and tensile tests are performed to examine the correlation of microstructure and mechanical properties for the intercritical annealed medium manganese steels containing Cu and Ni. The microstructures of all the steels are composed mostly of lath ferrite, reverted austenite and cementite, regardless of annealing temperature. The room-temperature tensile test results show that the yield and tensile strengths decrease with increasing intercritical annealing temperature due to higher volume fraction and larger thickness of reverted austenite. On the other hand, total and uniform elongations, and strain hardening exponent increase due to higher dislocation density because transformation-induced plasticity is promoted with increasing annealing temperature by reduction in reverted austenite stability.

• Journal of the Korean institute of surface engineering
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• v.43 no.1
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• pp.1-6
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• 2010

The effect of organic additives, 1-(3-sulfoproyl)-2-vinylpyridineium hydroxide (SVH) and thiourea (TU), on the precision copper electrodeposition was investigated with optical, electrochemical and x-ray diffraction techniques. It was found that SVH played a r ole as a n accelerator and TU as an i nhibitor during the electroreduction of cupric ions in acidic Cu electroplating solution. Through electrochemical measurements, TU showed more strong interaction with cupric ions than SVH and dominated overall Cu electroplating process when both additives were present in the solution. In the case of three dimensional Cu electrodeposition on the 20 ${\mu}m$-patterned Ni substrates, SVH controlled the upright growth of Cu electrodeposits and so determined its flatness, while TU prohibited the lateral spreading of Cu in the course of pulse-reverse pulse current adaptation. With microscopic observation, we obtained the optimum organic additives composition, that is, 100 ppm SVH and 200 ppm TU during the current pulsation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.2
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• pp.85-90
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• 1998

This paper describes the breakdown characteristics of GIS by the free conducting particles under alternating voltage. If the conducting particles are present within the GIS, they can cause decrease in breakdown voltages. Various materials and sizes of free conducting particles were used to study the liftoff electric field and breakdown voltage. The measured lift-off electric fields were compared with the calculated ones for copper, steel and aluminium wire-type conducting particles. As an experimental result, it is shown that the breakdown voltages of the GIS chamber with conducting particles were lower than those without conducting particles, and were markedly dependent on the particle material and the particle sizes. Free conducting particles are important factor in particle-triggered breakdown of the GIS.he GIS.

• Journal of the Korean Chemical Society
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• v.36 no.6
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• pp.849-856
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• 1992

We prepared a simple, economic and versatile preparative system for an enantiomeric separation. Hydrophobic amino acid enantiomers were resolved in the preparative scale by a centrifugal liquid chromatography on the N-hexadecyl-L-proline coated reversed phase. The factors controlling the retention and resolution of racemic amino acids such as the concentration of Cu(Ⅱ), pH of the eluent, the type and content of organic modifier, and rpm of CLC were examined. Several mg of hydrophobic amino acid enantiomers were separated preparatively. To separate all of different amino acid enantiomers, various coating material will be investigated.

• Korean Journal of Materials Research
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• v.17 no.5
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• pp.283-288
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• 2007

This study aimed to investigate the effects of the seed layer with copper electroplating on the surface morphology of copper foil. Three kinds of seed metal such as platinum, palladium, Pt-Pd alloy were used in this study. Electrodeposition was carried out with the constant current density of 200 $mA/cm^2$ for 68 seconds. Electrochemical experiments, in conjunction with SEM, XRD, AFM and four-point probe, were performed to characterize the morphology and mechanical characteristics of copper foil. Large particles were observed on the surface of the copper deposition layer when a copper foil was electroplated on the 130 nm thickness of Pd, Pt-Pd seed layer. However, a homogeneous surface, low resistivity was obtained when the 260 nm thickness of Pt, Pt-Pd alloy seed layer was used. The minimum value of resistivity was 2.216 ${\mu}{\Omega}-cm$ at the 260 nm thickness of Pt-Pd seed layer.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.1
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• pp.34-46
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• 2004

Copper films were prepared by using ECR-MOCVD(Electron Cyclotron Resonance Metal Organic Chemical Vapor Deposition) coupled with a DC bias system. The DC bias is connected to the electrode which placed 1∼3cm above the polymer substrate. The pulse electrical field around the electrode attracts the positive charged copper ions generated from the dissociation of copper precursor, $Cu(hfac)_2$, under ECR plasma. Condensation of supersaturated copper ions in the space between the electrode and substrate, makes it possible to deposit copper film on the polymer substrate even at room temperature. In this study, optimization of the electrode configuration was carried out in order to obtain the uniform films. The uniformity of the deposited films were closely related to the parameters of electrode geometry such as electrode shape, thickness, grid size and the spacing between electrodes. The most uniform copper film was observed with the electrode that enabled uniform electrical field distribution across the whole dimension of electrode.

• Korean Journal of Materials Research
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• v.16 no.12
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• pp.725-730
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• 2006

The purpose of this study is to identify the effect of additives during copper electrodeposition. Additives such as arabic gum, chloride ions and glue were used in this study. Electrochemical experiments allied to SEM and roughness examination were performed to characterize of the copper foil in the presence of additives. In the production of electrodeposited copper foil, the surface roughness and grain size of the copper foil can be controlled by addition additives. on this study, the more uniform and hemispherical copper crystals are during the initial stages, the smaller crystal size and surface roughness of copper foil are. The surface roughness of copper foil electrodeposited at the current density of 500 $mA/cm^2$ under galvanostatic mode for 60 seconds has a minimum value of 0.136 ${\mu}$m when adding 2 ppm of arabic gum.

• Resources Recycling
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• v.20 no.2
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• pp.60-66
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• 2011

Solvent extraction experiments were carried out to recover and separate Ru(III) from aqueous hydrochloric acid media using TBP and Cyanex923. The efficiency of the extraction was studied under various experimental conditions, such as concentration of HCl and NaCl, concentration of extractant in the organic phase and temperature. The extraction behavior of metal impurities, such as Pt, Bi, Sn, Fe, Pb and Cu in mixed solutions was examined. From the experimental studies, it was found that the Cyanex923 resulted in higher extraction percentage of Ru than TBP. However TBP was more effective for the separation of Ru and Pt, Bi, Sn in mixed solutions than Cyanex923.