• 한국초전도학회:학술대회논문집
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• v.15
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• pp.90-90
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• 2005

• Journal of the Korean institute of surface engineering
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• v.5 no.1
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• pp.1-7
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• 1972

Copper -clad laminate(CCL) was fabricated and evaluated by bonding 35${\pm}$5${\mu}$ thick electroplated copper foils with a suitable adhesive to an insulating base such as phenolic resin laminate. In this study, electroplating methods and conditions were studied to produced good quality copper foils for printed circuit board applications. The electroplating bath solutions used were a copper-sulfate solution and a concentrated copper fluoborate solution. A surface roughening treatment that improved the adhesive strength of copper foils with an insulating laminate was also developed . A conventional copper sulfate solution containing sulfuric acid was used for the roughening treatment.

• Korean Journal of Materials Research
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• v.18 no.3
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• pp.117-122
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• 2008

Micro-sized bumps on a multi-layered build-up PCB were fabricated by pulse-reverse copper electroplating. The values of the current density and brightener content for the electroplating were optimized for suitable performance with maximum efficiency. The micro-bumps thus electroplated were characterized using a range of analytical tools that included an optical microscope, a scanning electron microscope, an atomic force microscope and a hydraulic bulge tester. The optical microscope and scanning electron microscope analyses results showed that the uniformity of the electroplating was viable in the current density range of $2-4\;A/dm^2$; however, the uniformity was slightly degraded as the current density increased. To study the effect of the brightener concentration, the concentration was varied from zero to 1.2 ml/L. The optimum concentration for micro-bump electroplating was found to be 0.6 ml/L based on an examination of the electroplating properties, including the roughness, yield strength and grain size.

• Journal of the Korean institute of surface engineering
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• v.36 no.2
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• pp.194-199
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• 2003

Polarization measurements were peformed to investigate the electrochemical behavior of copper ions and limiting current density in waste rinse water from copper electroplating processes. A newly designed cyclone type electrolyzer was tested to recover the copper powder. Synthetic solutions were prepared using analytical grade $CuSO_4$ to the desired waste water concentration and pH was adjusted with $H_2$$SO_4$. Electrowinning was peformed at room temperature and the solution was cycled with a pump. Results showed that more than 99 percent of Cu was recovered and the size of the recovered Cu powder ranges from 0.1 - $0.5\mu\textrm{m}$. The chemical composition of the Cu powder mainly consists of $Cu_2$O and Cu and can be easily reduced to pure Cu powder.

• Journal of the Korean institute of surface engineering
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• v.43 no.6
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• pp.289-296
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• 2010

The effect of organic additives, thiourea (TU), on the copper electroplated layer of large rectangular size was investigated through physical and various electrochemical techniques. It was found that TU had strong adsorption characteristics on the Ni substrate and affected the initial electroplating process by inducing surface reaction instead of mass transfer in the bulk solution. TU additives had its critical micelle concentration at 200 ppm in copper sulphate solution and showed abrupt change in morphological and electrochemical impedance spectroscopic results around this concentration, which could be related with the destruction of adsorption structure of TU-Cu(I) complex formed at the Ni substrate surface. By conducting a commercial electroplating simulation, when TU additives was included at cmc in the plating solution, it acted as a depolarizer for copper electrodeposition and was effective to reduce the unevenness of copper deposits between centre and edge region at high current densities of 10 ASD.

• Journal of Electrochemical Science and Technology
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• v.11 no.1
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• pp.60-67
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• 2020

In this study, copper (II) oxide powder for electroplating was prepared by recovering CuCl₂ from NaClO₃ type etching wastes via recovered non-sintering two step chemical reaction. In case of alkali copper carbonate [mCuCo₃·nCu(OH)₂], first reaction product, CuCo₃ is produced more than Cu(OH)₂ when the reaction molar ratio of sodium carbonate is low, since m is larger than n. As the reaction molar ratio of sodium carbonate increased, m is larger than n and Cu(OH)₂ was produced more than CuCO₃. In the case of m has same values as n, the optimum reaction mole ratio was 1.44 at the reaction temperature of 80℃ based on the theoretical copper content of 57.5 wt. %. The optimum amount of sodium hydroxide was 120 g at 80℃ for production of copper (II) oxide prepared by using basic copper carbonate product of first reaction. At this time, the yield of copper (II) oxide was 96.6 wt.%. Also, the chloride ion concentration was 9.7 mg/L. The properties of produced copper (II) oxide such as mean particle size, dissolution time for sulfuric acid, and repose angle were 19.5 mm, 64 second, and 34.8°, respectively. As a result of the hole filling test, it was found that the copper oxide (II) prepared with 120 g of sodium hydroxide, the optimum amount of basic hydroxide for copper carbonate, has a hole filling of 11.0 mm, which satisfies the general hole filling management range of 15 mm or less.

• Journal of the Korean Vacuum Society
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• v.9 no.3
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• pp.267-272
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• 2000

Electroplating Cu was deposited on Si(100) wafer after seed Cu was deposited by sputtering first. TaN was deposited as a diffusion barrier before depositing the seed Cu. Electroplating Cu thin films show highly (111)-oriented microstructure for both before and after annealing at $450^{\circ}C$ for 30min and no copper silicide was detected in the same samples, which indicates that TaN barrier layer blocks well the Cu diffusion into silicon substrate. After annealing the electroplating Cu film up to $450^{\circ}C$, the Cu film became columnar from non-columnar, its grain size became larger about two times, and also defects density of stacking faults, twins and dislocations decreased greatly. Thus the heat treatment will improve significantly electromigration property caused by the grain boundary in the Cu thin films.

• Environmental Engineering Research
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• v.23 no.1
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• pp.92-98
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• 2018

Suitability of aluminium-based water treatment sludge (WTS), a waste product from water treatment facilities, was assessed for removal of heavy metals from an electroplating wastewater which had high concentrations of copper and chromium along with other heavy metals. Batch tests with simulated wastewater in single- and multi-metal solutions indicated the influence of initial pH and WTS dose on removal of six metals namely Cu(II), Co(II), Cr(VI), Hg(II), Pb(II) and Zn(II). In general, removal of cationic metals such as Pb(II), Cu(II) and Zn(II) increased with increase in pH while that of anionic Cr(VI) showed a reduction with increased pH values. Tests with multi-metal solution showed that the influence of competition was more pronounced at lower WTS dosages. Column test with diluted (100 times) real electroplating wastewater showed complete removal of copper up to 100 bed volumes while chromium removal ranged between 78-92%. Other metals which were present in lower concentrations were also effectively removed. Mass balance for copper and chromium showed that the WTS media had Cu(II) and Cr(VI) sorption capacities of about 1.7 and 3.5 mg/g of dried sludge, respectively. The study thus indicates that WTS has the potential to be used as a filtration/adsorption medium for removal of metals from metal-bearing wastewaters.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.1
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• pp.43-51
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• 2011

Natural convection heat transfer phenomena on a horizontal cylinder have been studied experimentally in order to investigate the applicability of analogy experimental methodology using a copper electroplating system and to visualize the local heat transfer rates depending on the angular position and the diameter of the horizontal cylinder. In the copper electroplating system, the copper ion produced at the anode moves by convection and diffusion to the cathode and reduces at the cathode, representing the heat transfer. By using aluminum cathode with a distinguishable color, the amount of copper plated could visualize the amount of heat transferred depending on the angular position of the cylinder. The diameter of the cylinder is varied from 0.01m to 0.15m, which correspond to Rayleigh numbers in the range of $1.73{\times}10^7$ to $5.69{\times}10^{11}$. The test results are in good agreement with existing heat transfer correlations.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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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.