• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.205-206
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• 2011

Cu thin films for electromagnetic wave shielding were prepared on PET film and Ni-coated PET film by using Dry and Wet coating method, such as evaporation method, DC sputtering method and copper sulfate($CuSO_4$). After that, Zn thin film and Ni thin film were prepared onto the Cu thin films by using evaporation dry process and Ni electro plating wet process as a finishing treatment, respectively. The result of conductivity test and corrosion resistance test revealed Cu thin films which were formed with bigger grain size and high Cu composition rate have superior properties. Zn thin film by dry evaporation process and Ni thin film by wet electro plating process on Cu thin films were largely contributed to corrosion resistance. However, Ni thin film by wet process made conductivity of all specimen worse, the other hand, Zn thin film by dry process made it better to improve condictivity of specimens just prepared by dry process.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.250-253
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• 2007

An evaporated Ti/Pd/Ag contact system is most widely used to make high-efficiency silicon solar cells, however, the system is not cost effective due to expensive materials and vacuum techniques. Commercial solar cells with screen-printed contacts formed by using Ag paste suffer from a low fill factor and a high shading loss because of high contact resistance and low aspect ratio. Low-cost Ni and Cu metal contacts have been formed by using electroless plating and electroplating techniques to replace the Ti/Pd/Ag and screen-printed Ag contacts. Ni/Cu alloy is plated on a silicon substrate by electro-deposition of the alloy from an acetate electrolyte solution, and nickel-silicide formation at the interface between the silicon and the nickel enhances stability and reduces the contact resistance. It was, therefore, found that nickel-silicide was suitable for high-efficiency solar cell applications. The Ni contact was formed on the front grid pattern by electroless plating followed by anneal ing at $380{\sim}400^{\circ}C$ for $15{\sim}30$ min at $N_{2}$ gas to allow formation of a nickel-silicide in a tube furnace or a rapid thermal processing(RTP) chamber because nickel is transformed to NiSi at $380{\sim}400^{\circ}C$. The Ni plating solution is composed of a mixture of $NiCl_{2}$ as a main nickel source. Cu was electroplated on the Ni layer by using a light induced plating method. The Cu electroplating solution was made up of a commercially available acid sulfate bath and additives to reduce the stress of the copper layer. The Ni/Cu contact was found to be well suited for high-efficiency solar cells and was successfully formed by using electroless plating and electroplating, which are more cost effective than vacuum evaporation. In this paper, we investigated low-cost Ni/Cu contact formation by electroless and electroplating for crystalline silicon solar cells.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.674-680
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• 2017

Touch Screen Panel (TSP) is a widely used personal handheld device and as a large display apparatus. This study examines micro bump fabrication technology for TSP test process. In the testing process, as TSP is changed, should make a new micro bump for probing and modify the testing program. In this paper we use a maskless lithography system to confirm the potential to fabricatemicro bump to reducecost and manufacturing time. The requiredmaskless lithography system does not use a mask so it can reduce the cost of fabrication and it flexible to cope with changes of micro bump probing. We conducted electro field simulation by pitches of micro bump and designed the lithography pattern image for the maskless lithography process. Then we conducted Photo Resist (PR) patterning process and electro-plating process that are involved in MEMS technology to fabricate micro bump.

• Polymer(Korea)
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• v.26 no.1
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• pp.105-112
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• 2002

The low actuation voltage and quick bending response of IPMC(ion-exchange polymer metal composite) are considered attractive for the construction of various types of actuators. In this study, in order to develop a new type actuators by using the IPMC platinum electrode of IPMC are fabricated by using electroless impregnation-reduction method plating. As the platinum-plating times are increased, IPMC performance was improved in terms of bending displacement and force due to the enhanced surface conductivity. In addition, we investigated the basic actuation characteristics of resonance frequency and actuator length as well as the effect of water uptake and ion mobility. Using the classical laminate theory(CLT), a modeling methodology was developed to predict the deformation, bending moment, and residual stress distribution of anisotropic IPMC thin plates. In this modeling methodology, the internal stress evolved by the unsymmetric distribution of water inside IPMC was quantitatively calculated and subsequently the bending moment and the curvature were estimated for various geometry of IPMC actuator.

• Journal of Surface Science and Engineering
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• v.41 no.5
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• pp.240-244
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• 2008

Composite plating is a method of co-deposition of plating layer with metallic and/or non-metallic particles to improve the plating layer properties such as high corrosion resistance and photolysis of organic compounds. The properties of nickel-ceramic composite plating are significantly depend on the surface characteristics of co-deposited particles as well as the quantity in electrolyte. In this study, Ni-$TiO_2$ composite coating layer was produced by electrodeposition technique from non-aqueous eletrolyte and its surface characteristics as well as photolytic properties were investigated. The amounts of immobilized $TiO_2$ particles increased with increasing the initial $TiO_2$ particles contents in the bath. Samples electroplated with the current density of $0.5\;A/dm^2$ showed the significantly improved homogeneous $TiO_2$ particles distribution. The corrosion resistance of Ni-$TiO_2$ composite coating layer also improved with increaing the amounts of $TiO_2$ particles. Etched sample showed about 10% increased photolytic rate of organic matter compare to that of the non-etched.

• Journal of Surface Science and Engineering
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• v.51 no.4
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• pp.191-196
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• 2018

The self-annealing which leads evolution of microstructure in copper electroplating layers at room temperature occurs after forming deposition layer. During the process, crystal orientation, size and sheet resistance of plating layer change. Lastly, it causes the change of physical and mechanical characteristics such as a tensile strength of plating layer. In this study, the variation of incorporated impurities, microstructure and sheet resistance of copper plating layer formed by electroplating are measured with and without inorganic additives during the self-annealing. In case of absence of inorganic additives, the copper layer presents strong total intensity of incorporated impurities. During the self-annealing, such width of reduction was significant. Moreover, microstructure and crystal size are increased while the tensile strength is decreased noticeably. On the other hand, in the presence of inorganic additives, there is no observable distinction in the copper plating layer. According to the observation on movements of the incorporated impurities in electrodeposition copper layer, within 12 hours the impurities are continuously shifted from inside of the plating layer to its surface after as-deposited electroplating. Within 24 hours, except for the small portion of surface layer, it is considered that most of the microstructure is transformed.

• Korean Journal of Metals and Materials
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• v.49 no.5
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• pp.411-418
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• 2011

The current study investigates the electroplating characteristics of Sn-Cu eutectic micro-bumps electroplated on a Si chip for flip chip application. Under bump metallization (UBM) layers consisting of Cr, Cu, Ni and Au sequentially from bottom to top with the aim of achieving Sn-Cu bumps $10\times10\times6$ ${\mu}m$ in size, with 20${\mu}m$ pitch. In order to determine optimal plating parameters, the polarization curve, current density and plating time were analyzed. Experimental results showed the equilibrium potential from the Sn-Cu polarization curve is -0.465 V, which is attained when Sn-Cu electro-deposition occurred. The thickness of the electroplated bumps increased with rising current density and plating time up to 20 mA/$cm^2$ and 30 min respectively. The near eutectic composition of the Sn-0.72wt%Cu bump was obtained by plating at 10 mA/$cm^2$ for 20 min, and the bump size at these conditions was $10\times10\times6$ ${\mu}m$. The shear strength of the eutectic Sn-Cu bump was 9.0 gf when the shearing tip height was 50% of the bump height.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.21-26
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• 2022

Zinc is emerging as a environment-friendly plating material to replace cadmium, which is harmful to the human body, to prevent hydrogen gas penetration or release from metal materials. Electroplating of Zn and Zn alloys, which is usually performed in an aqueous acidic atmosphere, has disadvantages such as low coulombic efficiency, corrosion, and hydrogen release, resulting in industrial use difficult. In this study, a deep-eutectic solvent was synthesized using choline chloride and ethylene glycol. Using this as a solvent, an electrolyte for Zn plating was prepared, and then zinc was plated on the STS 304 substrate. The surface microstructure and roughness were observed using SEM and AFM. The crystal structure of the electro-plated film was analyzed using XRD. Finally, the preventing effects of hydrogen release through Zn-based deep-eutectic plating on the STS 304 substrate were compared with the uncoated substrate.

• Resources Recycling
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• v.10 no.3
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• pp.23-28
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• 2001

Zinc ion could be recovered from metal plating wastewater with the spent iron oxide catalyst which was used in the plant of Styrene Monomer(SM) production. The zinc was recovered more than 98.7% at higher than pH 2.0. The saturation magnetization of the spent catalyst is enough high as 59.4 emu/g to apply in the solid-liquid separation after treating the wastewater. The mechanism of zinc recovery with the iron oxide catalyst could be a electro-chemical adsorption at pH 3.0~8.5, and a precipitation as $Zn(OH)_2$ at higher than pH 8.5.

• Electrical & Electronic Materials
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• v.9 no.1
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• pp.51-58
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• 1996

This report describes thick traveling-wave electrode formation and microwave transmission characteristics of the fabricated electrodes. Effective refractive indices of the microwave in the 5 micron CPW type traveling-wave electrodes is around 2.45 according to the results of time domain S parameter measurements. The bandwidth of the electrodes is about 10 GHz and could be extended to 15 GHz through optimization of the process. The developed process technique that enables plating of micropatterns upto 20 micron can be applied to broadband optical intensity modulators.