• 한국표면공학회지
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• 제40권2호
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• pp.70-76
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• 2007

Ni-P-SiC composite coating layers were prepared by electroless plating method and their deposition rate, codeposition of SiC, morphology, surface roughness, hardness, wear and friction properties were investigated. The deposition rate was kept almost constant independent of the concentration of SiC in the plating solution and the codeposition of SiC in the composite coating layer increased with increased concentration of SiC in the plating solution except the early stage. Vickers microhardness increased with respect to the increased codeposition of SiC and the heat treatment at $300^{\circ}C$ in air for 1 hour. It was found that the wear volume decreased with increased up to 50 wt.% of SiC codeposition, and that friction coefficient increased gradually with increased codeposition of SiC. Considering the wear and the friction behaviors, the composite coating layer obtained by using 50 wt.% of SiC codeposition is desirable for the practical application for anti-wear and anti-friction coatings.

• 한국분말재료학회지
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• 제18권5호
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• pp.430-436
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• 2011

Joining of NiO-YSZ to 316 stainless steel was carried out with B-Ni2 brazing alloy (3 wt% Fe, 4.5 wt% Si, 3.2 wt% B, 7 wt% Cr, Ni-balance, m.p. 971-$999^{\circ}C$) to seal the NiO-YSZ anode/316 stainless steel interconnect structure in a SOFC. In the present research, interfacial (chemical) reactions during brazing at the NiO-YSZ/316 stainless steel interconnect were enhanced by the two processing methods, a) addition of an electroless nickel plate to NiO-YSZ as a coating or b) deposition of titanium layer onto NiO-YSZ by magnetron plasma sputtering method, with process variables and procedures optimized during the pre-processing. Brazing was performed in a cold-wall vacuum furnace at $1080^{\circ}C$. Post-brazing interfacial morphologies between NiO-YSZ and 316 stainless steel were examined by SEM and EDS methods. The results indicate that B-Ni2 brazing filler alloy was fused fully during brazing and continuous interfacial layer formation depended on the method of pre-coating NiO-YSZ. The inter-diffusion of elements was promoted by titanium-deposition: the diffusion reaction thickness of the interfacial area was reduced to less than 5 ${\mu}m$ compared to 100 ${\mu}m$ for electroless nickel-deposited NiO-YSZ cermet.

• 마이크로전자및패키징학회지
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• 제11권2호
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• pp.11-16
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• 2004

전자칩의 고집적화에 의해 전자기기들은 점점 소형화 되어가고 있으며, 이들 기기들에서 발생되는 열은 기기의 성능 저하뿐 아니라 수명을 단축시킨다. 본 연구에서는 효율적인 방열 위한 마이크로 히트싱크 제조를 위하여 멤브레인에 금속(금, 니켈, 구리)은 도금하는 무전해 도금 방법을 이용하였다. 무전해 도금은 폴리카보네이트 멤브레인을 sensitization과 activation 등의 전처리 후, 도금하고자 하는 금속염 수용액에 침적시켜 실행하였다. 무전해 도금에 의하여 제조된 각각의 마이크로피브릴의 열전달 특성과 방열량은 표면적이 가장 큰 니켈 마이크로피브릴에서 가장 우수하게 나타났다.

• 대한금속재료학회지
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• 제48권5호
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• pp.462-468
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• 2010

Carbon Nanotubes (CNTs) have recently emerged as a material with outstanding properties. It has shown promising potential for applications in many engineering fields as electronic devices, thermal conductors, and light-weight composites. Researchers have investigated their use as reinforcements in themetal matrix composites of CNTs. In the present work, we decorated CNTs with Ni particles by electroless plating. The CNTs were wet-ball milled for various milling times with a nickel sulfate solution. The precipitated Ni particles were observed mainly by FESEM. In this study, the dispersion of the CNTs and Ni particles was improved with the addition of the surfactant. Also, as the CNTs were shortened and widened by an increased ball milling time, the size of the precipitated Ni particles increased. It was estimated that the CNTs were deformed and caused some defects on their surface during the ball milling process. Those defects were assumed to be heterogeneous nucleation sites for the Ni particles.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1630-1634
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• 2011

Electroless plating of metallic nickel on carbon fiber surfaces was carried out to control specific electric resistivity of the fibers, and the effects of the nickel content and coating thickness on the electric properties were studied. The structural and surface properties of the carbon fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The specific resistivity of the fibers was measured using a four-point probe testing method. From the XPS results, the oxygen and Ni atomic ratio of the fibers was greatly enhanced as the plating time increased. Additionally, it was observed that the specific electric resistivity decreased considerably in the presence of metallic nickel particles and with the formation of nickel layers on carbon fibers.

• 한국표면공학회지
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• 제24권4호
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• pp.206-214
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• 1991

In the basic study of selective electroless Ni plating of Si wafers, plating rate and physical properties are investigated to obtain optimum conditions of contact hole filling. Si wafers are excellently activated in the concentration of 0.5M IF, 1mM PdCl2, 2mM EDTA at $70^{\circ}C$, 90sec. The optimum condition of Ni-B deposition on p-type Si wafers is 0.1M NiSO4, 0.11M Citrate, $70^{\circ}C$, pH6.8, 8mM DMAB. The main factor in the sheet resistences variation of films is amorphous and on heat treating matrix was transformed into a stable phase (Ni+Ni3B) at $300-400^{\circ}C$. But pH or DMAB concentration in the plating solution doesn't play role of heat-affected phase change.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 기술심포지움 논문집
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• pp.118-121
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• 2003

The electrochemical behaviors of UBM nickel were investigated. Electrode potential has been changed with the surface composition. Zinc is dissolved into the solution immediately after immersion. Electrode potential has three distinct regions: Zinc dissolution region, transient region and nickel plating region. The effects additives on electrode potential and polarization curves were also investigated. The addition of suppressor lowered the current density which is related with deposition rate.

• Korean Chemical Engineering Research
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• 제59권2호
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• pp.269-275
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• 2021

메탄의 부분 산화반응을 위해 규칙적인 메조기공을 갖는 실리카를 지지체로 한 니켈 촉매를 제조하였다. 니켈 플레이팅(Nickel plating) 방법을 이용하여 촉매 제조 시 기존 함침 촉매 제조법과 달리 니켈이 실리카 표면에 도포된다. 이때 니켈이 고분산 되어 안정적인 니켈입자를 형성하게 된다. 니켈 플레이팅 촉매의 경우, TEM-EDS 분석에서 니켈이 매우 고분산 된 것을 확인할 수 있었다. 이러한 고분산된 촉매로 메탄 부분산화 반응 시 기존 함침촉매와는 달리 니켈의 소결과 탄소침적이 상대적으로 적어 촉매의 비활성화가 매우 낮았다. 팔라듐은 환원 조촉매로서의 역할을 하여, 메탄 전환율과 생성된 합성가스의 H2/CO 비 관점에서 우수한 반응 성능을 보이는 것을 확인 할 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.323-323
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• 2013

High power light-emitting diodes (LEDs) are widely used in many device applications due to its ability to operate at high power and produce high luminance. However, releasing the heat accumulated in the device during operating time is a serious problem that needs to be resolved to ensure high optical efficiency. Ceramic or Aluminium base metal printed circuit boards are generally used as integral parts of communication and power devices due to its outstanding thermal dissipation capabilities as heat sink or heat spreader. We investigated the characterisation of electroless plating of Ni-B film according to plating bath temperature, ranging from $50^{\circ}C$ to $75^{\circ}C$ on Ag paste/anodised Al ($Al_2O_3$)/Al substrate to be used in metal PCB for high power LED packing systems. X-ray diffraction (XRD), Field-Emission Scanning Electron Microscopy (FE-SEM) and X-ray Photoelectron Spectroscopy (XPS) were used in the film analysis. By XRD result, the structure of the as deposited Ni-B film was amorphous irrespective of bath temperature. The activation energy of electroless Ni-B plating was 59.78 kJ/mol at the temperature region of $50{\sim}75^{\circ}C$. In addition, the Ni-B film grew selectively on the patterned Ag paste surface.

• 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.