• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권12호
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• pp.601-607
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• 2002

IPMC(Ionic Polymer Metal Composite)actuators were optimized for producing improved forces by changing multiple parameters including repetition of number of plating, surface electroding and additive(PVP)-treatment on reduction. The platinum electrode is deposited on the surface of the material where platinum particle stay in a dense form that appears to introduce a significant level of surface electrode resistance. Actuation tests were performed for such IPMC actuators under a low voltage. The test results show that the lower surface-electrode resistance generates higher actuation capability in the IPMC actuators. In order to investigate relaxation behavior of bending and repeatability in dry condition, the IPMC was coated by$rubber(KRATON^{TM})$to minimize the effect of water evaporation from IPMC. This actuator can be used in air with surface coating to avoid membrane drying.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.251-254
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• 2002

The technique of high speed machining is widely studied in machining field. In this study, TiAIN single-layered and TiAIN/TiN double-layered coatings were applied to end-mill by an arc ion plating technique. Their performances were comparatively studied about cutting force, tool wear, tool life and surface roughness of workpiece under high speed cutting conditions. The TiAIN single-layer coated tool showed higher wear-resistance due to its higher hardness, while the TiAIN/TiN double-layer coated tool showed better performance for high metal removal, i.e., high fled per tooth condition due to its higher toughness. The surface roughness of the workpiece was not influenced by the wear amount of coated tools.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2002년도 춘계학술발표회 초록집
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• pp.36-36
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• 2002

Effects of pulse-plating on the wear and corrosion resistance of chrome-carbon layers were studied. The plating were carried out at $06A/\textrm{cm}^2$ in modified Sargent bath containing formic acid at $53^{\circ}C$. The chrome layer were super-saturated with carbon up to 2.0wt. %, which precipitated as chrome carbide such as $Cr_{23}C_6$ after vacuum aging above $200^{\circ}C$ for 1 hour. This resulted in improvement of hardness and wear resistance of the chrome layer. Considering the reduction of corrosion resistance due to the thermal effect, optimum vacuum aging condition of the chrome layer in this study was I-hour at $200^{\circ}C$.

• 한국표면공학회지
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• 제16권3호
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• pp.98-107
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• 1983

A study on the improvement of wear resistance of brasses by electroplating and diffusion treatment of tin was carried out. The optimum condition of the treatment obtained was as follows. Plating thickness of tin : 5 - 9 $\mu\textrm{m}$ Condition of diffusion treatment : atmosphere ; fused nitrate bath (KNO3 + NaNO3) temperature and time ; 1st step 320$^{\circ}C$, 60min. and 450$^{\circ}C$, 30min. During the diffusion treatment, internetallic compounds of Cu-Sn were formed and these compounds were identified as η, $\varepsilon$ and $\delta$ phase from the outer tin layer. It was considered that the improvement of wear resistance of brasses by the treatment is because of the formation of intemetallic compounds particalarly $\varepsilon$phase which is very hard, between soft tin layer brass.

• 마이크로전자및패키징학회지
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• 제30권1호
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• pp.49-54
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• 2023

최근 SIP (System in Packaging) 기술은 고주파(5G 이상) 통신 및 미세 피치 회로 특성을 만족해야 한다. 기존 ENIG (Electroless Ni/Immersion Au Plating) 표면처리는 전송 손실이 증가하여 고주파에 적합하지 않으므로, 니켈 도금층이 없어도 패턴 및 패드의 신뢰성 수준을 만족시킬 수 있는 표면 처리 기술이 검토되고 있다. 본 논문에서는 고주파 통신 대응을 위한 Ni-less 표면처리기술과 소재에 따른 주파수 특성 등에 대한 연구 동향을 조사하였다.

• 한국재료학회지
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• 제11권11호
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• pp.923-928
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• 2001

An electrolytic silver plating process has been successfully developed for terminated electrode parts of dielectric ceramic resonator. High adhesion strength and high Qu is obtained and blister occurance is minimized under plating condition with $HNO_3$750 $m\ell/\ell$ and HF $ 250m\ell/\ell$ solution at $25^{\circ}C$ for 20 minutes. Adhesion strength has the highest value, 3.2 kg/mm$^2$ at etching temperature of $25^{\circ}C$. Adhesion strength, Qu and blister occurance are monotonically increased with the thickness of electrodeposition layer. In case of electrodeposition of Ag, Qu value of 380 has obtained higher than in case of electrolytic Cu plating with Qu value of 325. Therefore, terminated electrode parts of dielectric ceramic resonator reducing dielectric loss can be obtained using prensent process.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2002년도 추계기술심포지움논문집
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• pp.49-53
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• 2002

The Sn-Cu eutectic solder bump formation ($140{\mu}{\textrm}{m}$ diameter, $250{\mu}{\textrm}{m}$ pitch) by electroplating was studied for flip chip package fabrication. The effect of current density and plating time on Sn-Cu deposit was investigated. The morphology and composition of plated solder surface was examined by scanning electron microscopy. The plating thickness increased with increasing time. The plating rate increased generally according to current density. After the characteristics of Sn-Cu plating were investigated, Sn-Cu solder bumps were fabricated on optimal condition of 5A/dm$^2$, 2hrs. Ball shear test after reflow was performed to measure adhesion strength between solder bump and UBM (Under Bump Metallization). The shear strength of Sn-Cu bump after reflow was higher than that of before reflow.

• 한국의류학회지
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• 제32권2호
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• pp.319-327
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• 2008

The purpose of this study is to propose the development of high quality electromagnetic wave shielding fabrics. Silver nitrate is used for polyester fabric as an electromagnetic wave shielding material. The effects of activators and electroless silver plating condition on the evenness and adhesion of silver to fabrics, are observed through the SEM micrographs. Surface morphology and wash-ability are measured using SEM. The results are as follows: The optimum weight loss by alkaline hydrolysis of polyester fabrics is about 20%. The optimum concentration of $SnCl_2$ and $PdCl_2$in catalyst reaction using $PdCl_2$ as an activator is 2.5g/L and 0.5g/L, respectively. The optimum concentration of dextrose to improve adhesion between the silver plating and fabrics is 45g/L. The optimum concentration of silver nitrate in the catalyst reaction, using $PdCl_2$ as an activator is 56g/L, respectively. The optimum plating temperature and time are $15^{\circ}C$ and 30minutes, respectively.

• 한국표면공학회지
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• 제29권5호
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• pp.545-548
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• 1996

$CrN_x$ films were deposited on SKD61 and S45C by cathodic arc ion plating process. In this study, the microstructure, microhardness, a hesion, wear and corrosion properties of the CrNx films were studied for various nitrogen partial pressures and the results were compared with those from the electroplated hard Cr. The crystal structure of the films was characterized by X-ray diffraction. Wear tests were performed under no lubricant condition at atmosphere by ball-on-disc type tribotester. Corrosion resistance of the films were studied by electrochemical corrosion test, measuring current demsity-potential curves. The results indicated that the $CrN_x$ films formed using ion plation method showed higer hardness and lower current density, friction coefficient than electroplated hard Cr. Consequently, the application of the CrNx coationgs by ion plating which is free of environmental pollution, is expected to improve lifetime of components in industrial practice.

• 한국표면공학회지
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• 제44권6호
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• pp.233-238
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• 2011

The friction and wear characteristics of CrN and TiN coatings on SKD61 which is mold material using for extrusion of AZ80 magnesium alloy were investigated. The coatings were deposited by the arc ion-plating method, and the thickness were about $3.59{\mu}m$ and $3.28{\mu}m$, respectively. Reciprocating friction wear tests were conducted by varying pin load and temperature of counter substrate at un-lubricated condition. The pin loads were 11, 15 and 19 kgf, and the substrate temperatures were room temperature and $120^{\circ}C$. CrN coating which has a lower friction coefficient and a smaller adhesive wear with AZ80 magnesium alloy showed better wear resistance than TiN coating.