• Current Photovoltaic Research
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• 제4권4호
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• pp.140-144
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• 2016

In this paper, core-shell structure of nickel/gold (Ni/Au) conductive layer on poly-methyl-methacrylate (PMMA) micro-ball was fabricated and its conduction property was investigated. Firstly, PMMA micro-ball was synthesized by using dispersion polymerization method. Size of the ball was $2.8{\mu}m$ within ${\pm}7%$ deviation, and appropriate elastic deformation of the PMMA micro-ball ranging from 31 to 39% was achieved under 3 kg pressure. Also, 200 nm thick Ni/Au conductive layer was fabricated on the PMMA micro-ball by uniformly depositing with electroless-plating. Adhesion of the conductive layer was optimized with help of surface pre-treatment, and the layer adhered without peeling-off despite of thermal expansion by collision with accelerated electrons. Composite paste containing core-shell structured particles well cured at low temperature of $130^{\circ}C$ while pressing the test chip onto the substrate to make electrical contact, and electrical resistance of the conductive layer showed stable behavior of about $6.0{\Omega}$. Thus, it was known that core-shell structured particle of the Ni/Au conductive layer on PMMA micro-ball was feasible to flexible electronics.

• 한국표면공학회지
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• 제36권3호
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• pp.242-250
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• 2003

Electrodeposition of Ni was carried out on copper substrate from Ni Sulfamate bath by DC and high frequency pulse current. During the electroplating, bath temperature was steady $60^{\circ}C$ , agitation was applied. Morphology and surface roughness of electrodeposits was investigated with the AFM. Crystalline structure of electrodeposits was investigated with XRD. Also, surface electric resistivity was investigated with 4-point probe. The result of crystalline structure by X-ray diffractometer, in the case of DC, <200> direction was dominant growing direction. But in the case of PC, the ratio of <200> direction vs. other direction decreased. As the pulse frequency increased, the enhanced properties of deposits were shown. With increasing frequency, the degree of surface properties increased DC more than that of PC, eg surface morphology, roughness and the degree of compactness of grains. With increasing duty cycle, the surface properties such as the degree of the morphology, roughness and electroconductivity was deteriorated.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 추계학술발표회 초록집
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• pp.56-56
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• 2001

Ni-W alloy deposit is one of the best alternatives to hard chromium plating because of its good mechanical properties (high hardness, high strength, and good wear resistance). Ni-W alloy is deposited from weakly acidic or alkaline electrolytic bath with nickel sulfate, sodium tungstate or APT, and some kinds of organic hydroxy-acid complex and ammonia salts. W content of the deposit can be changed from 0 to 5Owt% and the coating with high W content is more attracted. But, meanwhile, the deposited layers are always found high internal stress, which cause them to become brittle and to bond insufficiently with the substrate. On the second hand, as the W content is incresed, the current efficiency reduced, which results in large quantities of hydrogen evolution and then produces bubbles on surface and pitting appearance In this paper, the influence of some additives on Ni-W alloy electroplating was investigated by means of compositional analysis and SEM. The initial results showed that 2-butyne-1,4-diol was the best brightener for Ni-W plating process. It could brighten and level deposit, but decreased the cathodic current efficiency. Its optimum concentration range is from O.lgjL to 0.5gjL. Besides, three kinds of additives including 2-butyne-1,4-diol were examined with Dagguchi method.

• 대한금속재료학회지
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• 제49권11호
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• pp.905-909
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• 2011

The formation of front metal contact silicon solar cells is required for low cost, low contact resistance to silicon surfaces. One of the available front metal contacts is Ni/Cu plating, which can be mass produced via asimple and inexpensive process. A selective emitter, meanwhile, involves two different doping levels, with higher doping (${\leq}30{\Omega}/sq$) underneath the grid to achieve good ohmic contact and low doping between the grid in order to minimize the heavy doping effect in the emitter. This study describes the formation of a selective emitter and a nickel silicide seed layer for the front metallization of silicon cells. The contacts were thickened by a plated Ni/Cu two-step metallization process on front contacts. The experimental results showed that the Ni layer via SEM (Scanning Electron Microscopy) and EDX (Energy dispersive X-ray spectroscopy) analyses. Finally, a plated Ni/Cu contact solar cell displayed efficiency of 18.10% on a $2{\times}2cm^2$, Cz wafer.

• 한국재료학회지
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• 제5권8호
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• pp.1013-1019
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• 1995

본 연구에서는 무전해 도금범으로 polyester film 상에 Co-Ni-P 박막을 석출시키고, pH, 온도 그리고 도금용액의 농도에 따른 도금속도 및 석출된 도금박막의 합금조성과 합금조성에 따른 자기적 특성을 고찰하였다. 무전해도금의 석출속도는 pH 8.5, 온도 90℃일때 가장 좋았으며, 자기적 특성도 이 때가 가장 좋았다. 합금조성은 pH와 착화제의 농도에 따라서는 크게 변화하였으나, 그 밖의 인자들에 의해서는 변화하지 않았다. 최적조건에서 만들어진 박막의 합금조성은 코발트가 78%, 니켈이 16%, 인이 6%였고, 보자력은 370 Oe, 각형비는 0.65였다. 박막은 합금조성에 따라 경질자성막과 연질자성막의 두가지 형태로 변화했고, 니켈이 30% 이상 공석(共席)되었을 때, 연질자성막으로 되었다. 연질자성막일때, 합금박막의 결정구조는 니켈이 강하게 배향된 비정질 형태를 나타냈고, 경질자성 막일때는, 코발트(101)과 (100)면으로 배향된 α-코발트의 hcp 결정구조를 나타내었다.

• 한국표면공학회지
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• 제22권2호
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• pp.69-77
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• 1989

Codeposion of inert particles particles in a metallic mateix by electroless plating process involves two phenomena. Firstly, the adsorption of inercles and secondly, the adsorption of inert particles on the cathode. In the present paper the first adsorption phenomenon and in the next paper the second ane are studied in greaterdetail for the Ni-SiCc, Ni-Al2AO3 and Ni-WC systems. Measurements of the Zeta potentials for the SiC and Al2AO3 particles have been in different electrolyte solutions and the ionic species adsorbed on the Particles studied. The addition of sodium acetate, trisodium citrate and sodium phosphinate to nikel sulface sruomotes the zeta potential of SiC and Al2O3 particles, but zeta phosphinate to nickel is more positive than Al2O3 particles although the amount of nickel ion adsorbrd on the Al2O3 particles become greater than that of SiC particles. It is suggested that this is due to adsortion of Na ion onto the surface SiC particles.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 추계학술대회 논문집
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• pp.312-313
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• 2015

무전해 도금은 석출응력이 낮고 작업하기가 용이하기 때문에 산업분야에 있어서 중요한 역할을 한다. 무전해 도금 공정에 있어서, 니켈금속은 차아인산염, 아미노보레인 혹은 수소화붕소 화합물($HBF_4$)에 의한 니켈이온의 화학적 환원에 의해 도금된다. 환원반응이 진행함에 따라서 도금액 중에서 니켈과 차아인산염 이온은 감소한다. 이에 이러한 이온을 보충하기 위하여 도금액 중에 황산니켈과 차아인산나트륨이 일반적으로 첨가된다. 하지만 축적된 인산염, 황산염, 나트륨과 이외의 물질이 전착 박막의 품질을 떨어뜨리고 도금액은 폐기되기도 한다. 니켈회수 속도는 종래의 50% 이하였던 것이 90%이상으로 향상되었다. 이온교환법은 니켈도금 폐액으로부터 니켈회수에 필요한 친환경적이고 원가절감의 기술이라고 사료된다. 특히, 갈탄이 저렴하고 양이온 교환성능이 뛰어나다. 이유는 -COOH, -OH 등의 기능성 그룹을 갖기 때문이다. Fe-P 화합물은 식물에 유용하지 못하고 마그네슘과 칼슘 기반의 석출물은 저렴하고 취급이 용이하며 비료와 같이 재활용이 가능하기 때문에 일반적인 인의 제거 수단이 될 수 있다. 본고에서는 니켈도금 폐액으로부터 인을 제거하는 데 $Ca(OH)_2$, $CaCl_2$와 $CaCO_3$를 채택하여 인이 제거되는 정도를 비교하였고 니켈회수율을 높이기 위하여 갈탄을 사용하였다.

• 한국표면공학회지
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• 제27권4호
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• pp.193-206
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• 1994

A wear behavior of electroless (Ni-P-X, X: SiC, $Al_2O_3$, Diamond) composite coating layers, formed under various conditions on commerical grade low carbon steel, has been investigated using Taber abrasion tester and scanning electron microscope. Several factors, which are type of particles, co-deposited content, particle size, distribution of particles and heat-treatment, influenced the wear resistance. The wear resistance of the composited coating layers after heat-treatment at $400^{\circ}C$ for 1 hr was increased 70 times with diamond, 15 times with SiC and 8 times with $Al_2O_3$, compared with the electroless nickel plating layer without heat-treatment.

• Current Applied Physics
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• 제18권11호
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• pp.1235-1239
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• 2018

We present a novel process to fabricate three-dimensional (3D) metallic patterns from 3D printed polymeric structures utilizing different hygroscopic swelling behavior of two different polymeric materials. 3D patterns are printed with two different polymers as cube shape. The surface of the 3D printed polymeric structures is plated with nickel by an electroless plating method. The nickel patterns on the surface of the 3D printed cube shape structure are formed by removing sacrificial layers using the difference in the rate of hygroscopic swelling between two printing polymer materials. The hygroscopic behavior on the interfaced structure was modeled with COMSOL Multiphysics. The surface and electrical properties of the fabricated three-dimensional patterns were analyzed and characterized.

• Advances in nano research
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• 제14권2호
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• pp.195-200
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• 2023

Safety in sports is important because if an athlete has an accident, he may not be able to lead an everyday life for the rest of his life. The safety of sports facilities is very effective in creating people's sports activities, with the benefits of staying away from physical injury, enjoying sports, and mental peace. Everyone has the right to participate in sports and recreation and to ensure that they want a safe environment. This study prepares a very good Nickel-Cobalt -Silicon carbide (Ni/Co-SiC) nanocomposite with convenient geometry on the leg press machine rod, employing the pulse electrodeposition technique to reduce the rod's wear and increase the durability of sports equipment and control sports damages. The results showed that the Ni/Co-SiC nanocomposite formed at 2 A/dm2 shows extraordinary microhardness. The wear speed for the Ni/Co-SiC nanocomposite created at 4 A/dm2 was 15 mg/min, showing superior wear resistance. Therefore, the Ni/Co-SiC nanocomposite can reduce sports equipment's wear and decrease sports injuries. Ni-Co/SiC nanocomposite layers with various scopes of silicon carbide nanoparticles via electrodeposition in a Ni-Co plating bath, including SiC nanoparticles to be co-deposited. The form and dimensions of Silicon carbide nanoparticles are watched and selected using Scanning Electron Microscopy (SEM).