• Journal of the Korean institute of surface engineering
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• v.28 no.2
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• pp.83-91
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• 1995

A new method for preparation of thin nickel foam for Ni-MH battery was investigated. In this method, fine graphite powders of $1\mu\textrm{m}$～$2\mu\textrm{m}$ diameter were pasted into pores of thin polyurethane foam film in order to supply electric conducting seeds for nickel deposition by electroless plating reaction. After electroless plating, remaining polyurethane foam was removed chemically by organic solvent treatment and graphite particles also removed by ultrasonic cleaning. Porosity of formed nickel foam was about 85% During electroplating, porosity of the nickel foam decreased less than 5% up to $30\mu\textrm{m}$ coating thickness. And then it was electroplated and heat-treated to improve mechanical strength and ductility. Finally, thin nickel foam for Ni electrode of Ni-MH battery with 80% porosity and $350\mu\textrm{m}$～X$400\mu\textrm{m}$ thickness was obtained.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.326-326
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• 2015

본 연구에서는 전해도금을 이용하여 Ni-Pd 합금도금을 형성한 후 열처리 효과를 분석하였다. 전류밀도 $0.2{\sim}1.5A/dm^2$, $PdCl_2$ 1~5mM의 변화를 통해 Ni-Pd 합금도금의 함량을 변화시켰고 $100{\sim}400^{\circ}C$의 열처리를 하였다. 열처리 온도가 올라갈수록 경도는 급격히 떨어졌고 $300^{\circ}C$이후에서는 감소하였으나 감소폭이 작았다. 경도의 감소 원인은 열처리 후 Grain Size가 커지는 현상 때문이고 이는 XRD를 통해 확인하였다. 면저항의 경우 열처리를 하였을 경우 급격히 감소하고 $100^{\circ}C$ 이후에는 일정하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.137-138
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• 2011

구리 이온은 -0.40V (vs. SCE)에서 전기화학적 환원이 일어나는 반면, 니켈 이온은 -1.19V (vs. SCE)에서 전착이 발생한다. 따라서, 단일 도금욕조 내에서 Ni-Cu 합금도금층을 제조하기 위해서는 두 금속 이온종 간의 전위차를 줄여주어야 하는데, 이를 위해 본 연구에서는 $Na_3C_6H_5O_7{\cdot}2H_2O$를 착화제로 사용하였다. 다양한 Ni-Cu 합금 도금층의 조성을 얻기 위하여 기본 도금욕 내 황산니켈과 황산구리의 비율을 10:1로 설정하였다. 도금 공정 조건에 따른 합금 도금층 조성 변화를 관찰하기 위하여 도금액 pH와 교반 속도에 따른 도금층 조성 변화를 분석하였으며, 도금액의 UV-VIS과 도금층의 XRD 와 SEM 측정을 통하여 도금욕과 도금층 간의 상관 관계를 유추하였다. 본 도금액에 사용된 $Na_3C_6H_5O_7{\cdot}2H_2O$ 착화제의 효과는 pH3에서 가장 현저하였으며, pH 변화 및 교반 속도 변화를 이용하여 다양한 합금 조성을 얻을 수 있었다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.137-138
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• 2015

Ni-W 합금도금은 내마모성, 내산성 및 내열성 등의 여러 특성을 가지며 높은 피막경도도 안정하게 얻어지기 때문에 경질 Cr 도금의 대체도금으로서 유리 성형용 금형, 롤러 표면재료, 자동차 접동부품 등 다양한 공업 분야와 제품에 적용되고 있다. Ni-W 합금도금은 도금액 및 전해조건에 따라서 도금 피막에 균열이 생기는 경우가 있다. 도금 피막의 균열 발생요인으로서 도금재료의 환경온도에 의한 열응력, 도금 피막과 기재와의 팽창 수축 차이에 의한 영향을 생각할 수 있다. 도금 내부응력의 발생이유로서 공석한 수소의 이탈설, 결정합체설, 이외에 과잉 에너지설 및 결자결함설도 제안되고 있다.

• Resources Recycling
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• v.22 no.3
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• pp.91-99
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• 2013

Steel industry which has been accomplishes the base of our country economy, automobile and electronic industry are taking charge of the role, whose electroplating is important. Large amount of wastewater and various metal salts, including hazardous materials was generated from the electroplating pre-treatment, plating, washing and post-plating. Currently, the general wastewater follows in the environmental law and neutralization after controlling, sludge where the various metal is mixed reclaims below multiple regulative and trust it is controlling. The sludge which includes the gas price metal reclaims in the field and trust it controls. a reclamation price of land it is insufficient but and the control expense holds plentifully and it loses the gas price metal which is valuable. Consequently, The research regarding to recover a gas price metal actively from this waste water, it is advanced. A new method to recover valuable metals from electroplating wastewater synthesis of metal sulfides using topical methods utilizing iron oxidizing bacteria, reagent of sulfides and solvent extraction using an organic solvent, such as the development of the law to recover these metals and metal sulfides of wastewater using selective recovery have been studied. By using these wastewater treatment method under frequency above 95%, it has been obtained the valuable metal from the wastewater, where the metal ion of Fe, Cu, Zn and Ni complexes was mixed. As we discuss the wastewater, which has been discharged from electroplating process, it is important and will be applied to the resources of metal in the urban mine.

• Korean Journal of Materials Research
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• v.13 no.2
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• pp.101-105
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• 2003

In this study, we have investigated the availability of the electroless Ni-B plating for a diffusion barrier of the bus electrode. The Ni-B layer of 1$\beta$: thick was electroless deposited on the electroplated Cu bus electrode for AC plasma display. The layer was to encapsulate Cu bus electrode to prevent from its oxidation and to serve as a diffusion barrier against Cu contamination of the transparent dielectric layer in AC plasma display. The microstructure of the as-plated barrier layer was made of an amorphous phase and the structure was converted to crystalline at about 30$0^{\circ}C$. The concentration of boron was about 5∼6 wt.% in the electroless Ni-B deposit regardless of DMAB concentration. The electroless Ni-B deposit was coated on the surface of the electroplated Cu bus electrode uniformly. And the electroless Ni-B plating was found to be an appropriate process to form the diffusion barrier.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.9
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• pp.913-921
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• 2009

In this study, supercritical nano plating was performed to observe its effect on materials. Using supercritical carbon dioxide as a solvent, we observed how different pressures and temperatures of the supercritical fluid affected the process and its outcome. The plating current increases as pressure increases from 8 MPa to 16 MPa, but it decreases after that. Similarly, the plating current increases as temperature is increased from $35^{\circ}C$ to $45^{\circ}C$, but the current decreases after that. Also, the thickness of the wet electrolyte plating is about $35\sim50{\mu}m$, while the thickness of the plating done using supercritical fluid is about $20\sim25{\mu}m$. At the results, It to it is considered that supercritical nano plating enable to form more thin and stable plating than wet electroplating methods. Also both of the electroplating methods could be affected plating quality by surface condition, and the supercritical nano plating has been confirmed to product more uniform plating surface than wet electroplating.

• Journal of the Korean institute of surface engineering
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• v.36 no.5
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• pp.386-392
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• 2003

The electroplating process for a solder bump which can be applied for a flip chip was studied. Si-wafer was used for an experimental substrate, and the substrate were coated with UBM (Under Bump Metallization) of Al(400 nm)/Cu(300 nm)Ni(400 nm)/Au(20 nm) subsequently. The compositions of the bump were Sn-Cu and eutectic Sn-Pb, and characteristics of two bumps were compared. Experimental results showed that the electroplated thickness of the solders were increased with time, and the increasing rates were TEX>$0.45 <\mu\textrm{m}$/min for the Sn-Cu and $ 0.35\mu\textrm{m}$/min for the Sn-Pb. In the case of Sn-Cu, electroplating rate increased from 0.25 to $2.7\mu\textrm{m}$/min with increasing current density from 1 to 8.5 $A/dm^2$. In the case of Sn-Pb the rate increased until the current density became $4 A/dm^2$, and after that current density the rate maintains constant value of $0.62\mu\textrm{m}$/min. The electro plated bumps were air reflowed to form spherical bumps, and their bonded shear strengths were evaluated. The shear strength reached at the reflow time of 10 sec, and the strength was of 113 gf for Sn-Cu and 120 gf for Sn-Pb.

• 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 Microelectronics and Packaging Society
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• v.20 no.1
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• pp.39-43
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• 2013

The experiments were carried out in the variation of current density, pH, temperature, and duty cycle to investigate the influence of electroplating parameters on the properties of Ni-Fe invar alloys. When the current density and temperature were changed, the composition of invar alloy was varied, however, duty cycle and pH hardly affected on the composition of electrodeposited alloys. However, as the duty cycle was increased, microstructure was changed and the decrease of hardness was also observed.