• 반도체디스플레이기술학회지
• /
• 제13권3호
• /
• pp.51-55
• /
• 2014

Ni-CNT(Carbon Nanotubes) composite coating is often used for the surface treatment of mechanical/electronic devices to improve the properties of the Ni coating. For the Ni-CNT coating, the dispersion of CNT fibers is a critical process. In this study, ultrasonic treatment instead of the conventional ball milling was attempted as a dispersion method for the electroless Ni-CNT coating. SEM-EDX analysis was performed and contact angle, sheet resistance, and micro-hardness were measured. Results showed that the ultrasonic treatment was comparable to the ball milling, as a dispersion method, but the difference was negligible. However, combined ball milling and ultrasonic treatment(double treatment) showed much improved micro-hardness value, above 350Hv(close to the value obtained by the Ni-CNT electroplating). In addition, electroless Ni-CNT(double-treated) coatings formed on the thin Ni film deposited by the electroless plating(double coating) showed better mechanical properties. Thus, double treatment and double coating are suggested as an improved electroless Ni-CNT coating method.

• 한국재료학회지
• /
• 제23권11호
• /
• pp.661-665
• /
• 2013

We investigated the characteristics of electroless plated Cu films on screen printed Ag/Anodized Al substrate. Cu plating was attempted using neutral electroless plating processes to minimize damage of the anodized Al substrate; this method used sodium hypophosphite instead of formaldehyde as a reducing agent. The basic electroless solution consisted of $CuSO_4{\cdot}5H_2O$ as the main metal source, $NaH_2PO_2{\cdot}H_2O$ as the reducing agent, $C_6H_5Na_3O_7{\cdot}2H_2O$ and $NH_4Cl$ as the complex agents, and $NiSO_4{\cdot}6H_2O$ as the catalyser for the oxidation of the reducing agent, dissolved in deionized water. The pH of the Cu plating solutions was adjusted using $NH_4OH$. According to the variation of pH in the range of 6.5~8, the electroless plated Cu films were coated on screen printed Ag pattern/anodized Al/Al at $70^{\circ}C$. We investigated the surface morphology change of the Cu films using FE-SEM (Field Emission Scanning Electron Microscopy). The chemical composition of the Cu film was determined using XPS (X-ray Photoelectron Spectroscopy). The crystal structures of the Cu films were investigated using XRD (X-ray Diffraction). Using electroless plating at pH 7, the structures of the plated Cu-rich films were typical fcc-Cu; however, a slight Ni component was co-deposited. Finally, we found that the formation of Cu film plated selectively on PCB without any lithography is possible using a neutral electroless plating process.

• 한국레이저가공학회지
• /
• 제3권2호
• /
• pp.25-33
• /
• 2000

One of perspective direction of microfabrication is direct laser writing technology that allows to create metal, semiconductive and dielectric micropatterns on substrate surface. In this work, a two step method, the combination of seed forming process, in which metallic Al seed was selectively generated on AlN ceramic substrate by direct writing technique using a pulsed Nd : YAG laser and subsequent electroless Ni plating on the activated Al seed, was presented. The effects of laser parameters such as pulse energy, scanning speed and pulse frequency on shape of Alseed and conductor line after electroless Ni plating were investigated. The nature of the laser activated surface is analyzed from XPS data. The line width of this metallic Al and Ni is analyzed using SEM. As a results, Al seed line with 24㎛ width and 100㎛ isolated line space is obtained. Finally, laser direct writing can be applied in the field between thin and thick film technique in electronic industry.

• 폴리머
• /
• 제25권2호
• /
• pp.218-225
• /
• 2001

복합재료의 기계적 계면 특성을 향상시키기 위하여 탄소섬유에 무전해 니켈도금 표면처리를 하였으며, 표면처리된 PAN계 탄소섬유를 에폭시수지에 함침시켜 프리프레그법으로 일방향 탄소섬유/에폭시수지 복합재료를 제조하였다. 본 연구에서는 무전해 니켈도금으로 유기된 취성-연성 전이 특성을 가지는 Ni-P 합금의 양에 따른 복합재료의 층간전단강도(ILSS)와 충격강도의 차이를 조사하였다. 또한, 탄소섬유 표면 특성의 변화를 X-ray photoelectron spectroscopy (XPS)로 측정하였다. 그 결과, 무전해 니켈도금된 탄소섬유 표면의 $O_{ls}$ /$C_{ls}$ 비 또는 니켈 (Ni)과 인 (P)이 증가되었으나 ILSS의 향상에는 큰 영향을 미치지 못하는 것을 알 수 있었다. 그러나, 무전해 니켈도금으로 탄소섬유 표면에 도입된 Ni-P 합금은 복합재료의 연성에 따른 충격강도를 향상시키는 것을 확인할 수 있었다.

• Corrosion Science and Technology
• /
• 제4권6호
• /
• pp.222-225
• /
• 2005

The adhesion strength of metal plating on PC was studied. In this study, surface was treated by chemical agents or DBD(dielectric barrier discharge) plasma to imporve the adhesion. The surface roughness, contact angle, gloss of plating and adhesive strength were measured. Adhesion strengths of Ni plating on prepared PC by NaOH and KOH solution were $12.3kgf/cm^2$ and $7.5kgf/cm^2$, respectively. The highest adhesion strength was obtained in the plasma treated one, $27.8kgf/cm^2$.

• 마이크로전자및패키징학회지
• /
• 제8권3호
• /
• pp.55-62
• /
• 2001

최근 전자 제품에서 사용이 폭발적으로 증가하고 있는 BGA, CSP 등의 면실장형 부품의 폭 넓은 채용에 따라서 베어 보드에서 solderability에 영향을 미치는 평탄한 표면 처리에 대한 요구는 갈수록 증가되고 있다. 무전해 Ni/Au도금 처리는 이러한 요구에 대한 해결책을 가지고 있어서 많은 전자제품에서 평탄한 표면 처리를 요구하는 응용 분야에 폭 넓게 사용되고 있다. 그러나, 무전해 Ni/Au 도금은 평탄한 표면 처리를 가지는 반면에 도금 공정에서 Ni의 산화와 적정한 P성분과 같은 몇 가지 해결요소를 가지고 있는 실정이다. 본 연구에서는 무전해 Ni/Au 도금 처리를 한 보드에서 BGA의 solderability에 미치는 영향을 사전 조사한 후, NiP 산화 특성과 보드의 휨과 간은 주요 인자를 선정하였다. 이를 위하여 먼저, 다양한 도금 조건을 가지는 테스트 보드를 제작한 후, 도금 공정에서 P성불을 감소시켜 NiP 산화 특성을 개선하였다. 또한 다양한 내층 구조와 휨 분석을 통해 내층 구조를 개선하여 보드의 휨을 최소화하였다. Solderability의 평가를 위해서 최적의 조건으로 제작된 보드에 BGA를 실장하여 보드의 휨과 도금 특성을 분석하였다. BGA의 접합부 조직은 주사 전자현미경(SEM: Scanning Electronic Microscope)과 광학 현미경(Optical Microscope)으로 관찰하였으며, 성분 분석은 EDS(Energy Dispersive Spectroscopy)를 활용하였다. 또한 기계적인 특성은 ball shear tester를 사용해서 파괴 강도와 모드를 분석하였다.

• Transactions on Electrical and Electronic Materials
• /
• 제14권3호
• /
• pp.133-138
• /
• 2013

Acrylonitrile-butadiene-styrene (ABS) plastic is a polymer material extensively used in electrical and electronic applications. Nickel (Ni) thin film was deposited on ABS by electroless plating, after its surface was treated and modified with atmospheric plasma generated by means of dielectric barrier discharges (DBDs) in air. The method in this study was developed as a pre-treatment for electroless plating using DBDs, and is a dry process featuring fewer processing steps and more environmentally friendliness than the chemical method. After ABS surfaces were modified, surface morphologies were observed using a scanning electron microscope (SEM) to check for any physical changes of the surfaces. Cross-sectional SEM images were taken to observe the binding characteristics between metallic films and ABS after metal plating. According to the SEM images, the depths of ABS by plasma are shallow compared to those modified by chemically treatment. The static contact angles were measured with deionized (DI) water droplets on the modified surfaces in order to observe for any changes in chemical activities and wettability. The surfaces modified by plasma showed smaller contact angles, and their modified states lasted longer than those modified by chemical etching. Adhesion strengths were measured using 3M tape (3M 810D standard) and by 90° peel-off tests. The peel-off test revealed the stronger adhesion of the Ni films on the plasma-modified surfaces than on the chemically modified surfaces. Thermal shock test was performed by changing the temperature drastically to see if any detachment of Ni film from ABS would occur due to the differences in thermal expansion coefficients between them. Only for the plasma-treated samples showed no separation of the Ni films from the ABS surfaces in tests. The adhesion strengths of metallic films on the ABS processed by the method developed in this study are better than those of the chemically processed films.

• 한국표면공학회지
• /
• 제40권2호
• /
• pp.70-76
• /
• 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.

• 한국결정성장학회지
• /
• 제25권5호
• /
• pp.193-198
• /
• 2015

본 연구에서는 전자파 차폐형 MCT(multi cable transit)의 인서트블록에 사용되는 유연성 EPDM(ethylene propylene diene monomer)고무 상에 무전해 도금을 이용하여 니켈도금을 실시하였다. 도금욕의 공정변수 조절 즉 pH 및 온도에 따라 Ni 도금층의 결정성 및 부착력이 결정되었다. pH와 온도를 달리하여 합성 한 결과 pH 7 및 8, $60{\sim}70^{\circ}C$에서 얻은 도금막들에서 잘 발달된 결정상과 높은 전기 전도도를 가짐을 알 수 있었다. pH 7, $70^{\circ}C$에서 도금 시 가장 높은 부착력 및 전기전도도를 얻을 수 있었으며, 또한 400 MHz~1 GHz 범위에서 우수한 전자파 차단능을 얻을 수 있었다.

• Composites Research
• /
• 제20권5호
• /
• pp.43-48
• /
• 2007

전자기파의 흡수와 간섭 문제는 상업적, 군사적 용도에서 중요한 문제로 다루어져 왔다. 스텔스 기술은 전자기파 흡수 기술의 가장 전형적인 적용 방법 중에 하나이다. 본 연구는 유전성 및 자성 손실을 함유한 복합성의 필러를 개발하고자 시작되었다. 전도성 나노 소재인 탄소나노섬유 (CNFs)에 자성을 부여하기 위해 두 가지의 니켈-인과 니켈-철을 무전해 도금을 적용하여 각각 코팅하는 실험에 성공하였다. 제작된 복합 소재의 미세 구조를 SEM/TEM을 통해 관찰하였고, 이들의 성분 분석(EDS/ELLS)을 수행하였다. 코팅 층의 평균 두께는 약 $50\;{\sim}\;100\;nm$의 결과를 나타내었으며, 코팅 층의 성분은 Ni-6wt%P와 Ni-70wt%Fe의 결과를 각각 나타내었다.