• Journal of Electrochemical Science and Technology
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• 제12권4호
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• pp.387-397
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• 2021

Deep eutectic solvents have been established as feasible metal electroplating solvent alternatives over traditional toxic aqueous plating baths. However, water, either added intentionally or unintentionally, can significantly influence the solvent's physical properties and performance, thereby hindering its industry application. In this study, the hygroscopicity, or the ability to absorb moisture from the environment, of synthesized ethaline (1:2 choline chloride:ethylene glycol) was investigated. The kinematic viscosity, electrical conductivity, electrochemical window, and water content of ethaline were monitored over a 2-week period. Karl Fischer titration tests showed that ethaline exposed to the atmosphere displayed significant hygroscopicity compared to its unexposed counterpart. ¹H NMR spectroscopy revealed that water vapor was readily absorbed at the surface due to the hydrophilic groups present in the ethaline molecule. Water uptake resulted in the decrease in viscosity, increase in electrical conductivity and narrowing of the electrochemical window of ethaline. Solution heating at 100℃ removed the absorbed moisture and allowed the recovery of the solvent's initial properties.

• 전기학회논문지
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• 제56권8호
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• pp.1436-1440
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• 2007

Beryllium copper has been known to be an important material for the various fields of industry because it can be used for mechanical and electrical/electronic components that are subjected to elevated temperatures (up to $400^{\circ}C$ for short times). Blade type tip for probing the cells of liquid crystal display(LCD) was fabricated using beryllium copper foil. The dry film resist was employed as a mask for patterning of the blade type tip. The beryllium copper foil was etched using hydrochloric acidic iron-chloride solution. The concentration, temperature, and composition ratio of hydrochloric acidic iron-chloride solution affect the etching characteristics of beryllium copper foil. Nickel with the thickness of $3{\mu}m$ was electroplated on the patterned copper beryllium foil for enhancing its hardness, followed by electroplating gold for increasing its electrical conductivity. Finally, the dry film resist on the bridge was removed and half of the nickel was etched to complete the blade type tip.

• 한국표면공학회지
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• 제32권3호
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• pp.208-210
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• 1999

A new additive for semi-brightness finish in nickel electroplating, having a quarternary ammonium salt structure, has been developed in this study. The effectiveness of the new additive was tested in laboratory-scale eletroplating tests as well as in a full-scale factory plating line. An examination of the plated surface showed that the new additive is as good as the one produced by the most commonly used additive in the nickel plating industry. The plated surface was examined by SEM, EPMA, and Reflectance Spectroscopy, and was found to be compatible to the one obtained with commercial additives. The new additive has a shelf life comparable with those of other commercially available additives. The additive developed in this study has an excellent potential to be used commercially.

• 한국표면공학회지
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• 제37권5호
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• pp.263-272
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• 2004

High strength steels such as transformation induced plastic steel, dual phase and solid solution Hardening have been developed and continuously improved due to the intensified needs in the automotive industry. But silicon and manganese in transformation induced plastic steels were known to exhibit harmful effects on galvannealing reaction by oxide film formed during heat treatment. Therefore, in this work, the applicability of Zn-Ni electrodeposition instead of hot dip galvannealed coating to transformation induced plastic steels was evaluated and optimum electroplating condition was investigated. Based on these investigations optimized electroplating conditions were proposed and Zn-Ni electrogalvanized steel sheet was produced by EGL (electrogalvanized line). Its perfomance properties for automotive steel was evaluated.

• 한국표면공학회지
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• 제32권3호
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• pp.219-223
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• 1999

A new additive for semi-brightness finish in nickel electroplating, having a quarternary ammonium salt structure, has been developed in this study. The effectiveness of the new additive was tested in laboratory-scale eletroplating tests as well as in a full-scale factory plating line. An examination of the plated surface showed that the new additive is as good as the one produced by the most commonly used additive in the nickel plating industry. The plated surface was examined by SEM, EPMA, and Reflectance Spectroscopy, and was found to be compatible to the one obtained with commercial additives. The new additive has a shelf life comparable with those of other commercially available additives. The additive developed in this study has an excellent potential to be used commercially.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 기술심포지움 논문집
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• pp.84-87
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• 2003

Since Pb-free solder alloys have been used extensively in microelectronic packaging industry, the interaction between UBM (Under Bump Metallurgy) and solder is a critical issue because IMC (Intermetallic Compound) at the interface is critical for the adhesion of mechanical and the electrical contact for flip chip bonding. IMC growth must be fast during the reflow process to form stable IMC. Too fast IMC growth, however, is undesirable because it causes the dewetting of UBM and the unstable mechanical stability of thick IMC. UP to now. Ni and Cu are the most popular UBMs because electroplating is lower cost process than thin film deposition in vacuum for Al/Ni(V)/Cu or phased Cr-Cu. The consumption rate and the growth rate of IMC on Ni are lower than those of Cu. In contrast, the wetting of solder bumps on Cu is better than Ni. In addition, the residual stress of Cu is lower than that of Ni. Therefore, the alloy of Cu and Ni could be used as optimum UBM with both advantages of Ni and Cu. In this paper, the interfacial reactions of Sn-3.5Ag-0.7Cu solder on Ni-xCu alloy UBMs were investigated. The UBMs of Ni-Cu alloy were made on Si wafer. Thin Cr film and Cu film were used as adhesion layer and electroplating seed layer, respectively. And then, the solderable layer, Ni-Cu alloy, was deposited on the seed layer by electroplating. The UBM consumption rate and intermetallic growth on Ni-Cu alloy were studied as a function of time and Cu contents. And the IMCs between solder and UBM were analyzed with SEM, EDS, and TEM.

• 소성∙가공
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• 제18권4호
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• pp.310-316
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• 2009

Micro lens array(MLA) is widely used in information technology(IT) industry fields for various applications such as a projection display, an optical power regulator, a micro mass spectrometer and for medical appliances. Recently, MLA have been fabricated and developed by using a reflow method having the processes of micro etching, electroplating, micro machining and laser local heating. Laser thermal relaxation method is introduced in marking of microdots on the surface of densified glass. In this paper, we have proposed a new direct fabrication process using UV laser local thermal-expansion(UV-LLTE) and investigated the optimal processing conditions of MLA on the surface of negative photo-resist material. We have also studied the 3D shape of the micro lens obtained by UV laser irradiation and the optimal process conditions. And then, we made chrome mold by electroplating. After that, we made MLA using chrome mold by hot embossing processing. Finally, we have measured the opto-physical properties of micro lens and then have also tested the possibility of MLA applications.

• 대한토목학회논문집
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• 제8권2호
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• pp.89-98
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• 1988

본 연구는 도금공장에서 생산된 슬러지를 시멘트 고형화방법을 이용하여 처리할 때 고형화에 영향을 미치는 인자들 중에 모래/시멘트 비, 물시멘트 비, 젖은 슬러지의 양, 그리고 중금속 용출방지제를 네가지의 인자로 하여 압축강도와 용출량의 변화를 살펴 보았다. 모래/시멘트 비는 Cr(VI) 용출에 가장 큰 영향을 미치는 인자이며, 물/시멘트 비는 Zn와 압축강도에 가장 큰 영향을 미치는 인자였다. Cr(VI)는 Zn보다 시멘트 고형화에서 leachability가 더 적었다. 현장에서의 Cr(VI)과 Zn 그리고 압축강도를 예측하기 위한 모델을 계발하였으며, 고체화의 3급 Brick으로의 이용을 위해 혼합조건을 제시하였다. 그리고 30g의 건조슬러지를 고형화할 때 최적조건은 모래/시멘트 비, 물/시멘트 비, 그리고 중금속 용출방지제의 양은 각각 1, 1.5, 1.075g이었다.

• 방사선산업학회지
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• 제8권3호
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• pp.141-146
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• 2014

Nickel (Ni) electroplating was implemented by using a metal Ni powder in order to establish a $^{63}Ni$ plating condition on the PN junction semiconductor needed for production of beta-voltaic battery. PN junction semiconductors with a Ni seed layer of 500 and $1000{\AA}$ were coated with Ni at current density from 10 to $50mA\;cm^{-2}$. The surface roughness and average grain size of Ni deposits were investigated by XRD and SEM techniques. The roughness of Ni deposit was increased as the current density was increased, and decreased as the thickness of Ni seed layer was increased. The results showed that the optimum surface shape was obtained at a current density of $10mA\;cm^{-2}$ in seed layer with thickness of $500{\AA}$, $20mA\;cm^{-2}$ of $1000{\AA}$. Also, pure Ni deposit was well coated on a PN junction semiconductor without any oxide forms. Using the line width of (111) in XRD peak, the average grain size of the Ni thick firm was measured. The results showed that the average grain size was increased as the thickness of seed layer was increased.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.83-89
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• 2012

Due to the potential importance and usefulness, usage of highly ordered nanoporous anodized aluminum oxide can be broadened in industry, when highly ordered anodized aluminum oxide can be placed on a substrate with controlled thickness. Here we report a facile route to highly ordered nanoporous alumina with the thickness of hundreds-of-nanometer on a silicon wafer substrate. Hexagonally or tetragonally ordered nanoporous alumina could be prepared by way of thermal imprinting, dry etching, and anodization. Adoption of reusable polymer soft molds enabled the control of the thickness of the highly ordered porous alumina. It also increased reproducibility of imprinting process and reduced the expense for mold production and pattern generation. As nanoporous alumina templates are mechanically and thermally stable, we expect that the simple and costeffective fabrication through our method would be highly applicable in electronics industry.