• Korean Journal of Metals and Materials
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• v.48 no.10
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• pp.951-956
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• 2010

This study examined the effect of copper and sulfuric acid concentrations on the surface morphology and physical properties of copper plated on a polyimide (PI) film. Electrochemical experiments with SEM and a four-point probe were performed to characterize the morphology and mechanical characteristics of copper electrodeposited in the composition of an electrolyte. The resistivity and peel strength were controlled using a range of electrolyte compositions. A lower resistivity and high flexibility were obtained when an electrolyte with 20 g/l of copper was used. However, a uniform surface was obtained when a high current density that exceeded $20mA/cm^2$ was applied, which was maintained at copper concentrations exceeding 40 g/l. Increasing sulfuric acid to >150 g/l decreased the peel strength and flexibility. The lowest resistivity and fine adhesion were detected at a $Cu^{2+}:H_2SO_4$ ratio of 50:100 g/l.

• Journal of the Korean Magnetics Society
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• v.14 no.1
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• pp.52-57
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• 2004

In this research, characteristics of air core rectangular spiral type inductors of ㎓ band are numerical analyzed. The basic structure of inductors is a rectangular spiral having 390${\mu}{\textrm}{m}$${\times}$390${\mu}{\textrm}{m}$ size, 5.5 turns, line width of 10 ${\mu}{\textrm}{m}$ and line space of 10 ${\mu}{\textrm}{m}$. Frequency characteristics were simulated up to 10 ㎓. The substrate was modeled as Si, Sapphire, glass and GaAs and the conductor as Cu. The thickness of the conductor was fixed at 2. The number of turns was n.5 to make the input and output terminals to be on the opposite sides. The initial inductance of the basic inductor structure was 13.0 nH, maximum inductance 60.0 nH and resonance frequency 4.25 ㎓. As the dielectric constant of the substrate was increased, the initial inductance varied only slightly, but the resonance frequency decreased considerably. As the number of turns was varied from 1.5 to 9.5, the initial inductance was increased linearly from 2.9 nH to 15.9 nH and, then, saturated at 16.9 nH. The Q factor increased only slightly. The line width and line space of inductors were varied from 5 ${\mu}{\textrm}{m}$ to 20 ${\mu}{\textrm}{m}$, which resulted in the decrease of the initial and maximum inductances. But the resonance frequency was increased. Q factor displayed an increase and a decrease, respectively, when the line width and line space were increased.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.72-76
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• 2003

Ultrafiltration (UF) tests performed on traditional soy sauce (kanjang) using UF flat membrane test cell unit with thin film laminar flow similar to the spiral type membrane module in batch operations revealed reduction in permeate flux is proportional to the logarithm values of volume reduction ratio of the retentate kanjang at different feed rate of kanjang. Feed rate of 1.5 L/min was found to be adequate for long-term UF operation of kanjang using the test unit attached with MW cut-off size of 200,000 dalton polyoleffin plastic membrane in batch operation with the least concentration polarization. The higher the feed rate of kanjang, the lower the permeability of total nitrogen and NaCl, resulting in lower optical density at 500 nm and lower permeability of minerals such as Cu, Mn, and Mg. Microbial cells were completely rejected regardless of the feed rate, whereas most free amino acids were not.

• Journal of the Korean Vacuum Society
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• v.18 no.1
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• pp.1-8
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• 2009

Hydrophilic Surface modification of Polysarene (PS) was performed by Atmospheric Pressure Plasma (APP). Air or 0, gases were used for carrier gases and RF power was changed from 150 to 350 W. We controlled the treatment time as 1 time to 4 time passing through the plasma region. when the carrier gas was air, the water contact angle on the PS surface was decreased from $91^{\circ}$ to $20^{\circ}$. And the surface energy increased from 45.74 dyne/cm to 68.48 dyne/cm. In case of the $O_2$ plasma treatment, at 300 W of RF power and 4 times treatment, the water contact angle on the PS. Surface was decreased from $91^{\circ}$ to $17^{\circ}$ and the surface energy was increased from 45.74 dyne/cm to 69.73 dyne/cm. The surface energy was increased by polar force not by dispersion force. Improvement of surface properties can be explained by the formation of new hydrophilic groups which is identified as C-O, C=O by XPS analysis. The contact angle of APP treated PS surface kept in air was increased with time elapse, but maintained same value when it was kept in water. We treated the PS surface by APP and deposited Cu as $4,000\;{\AA}$ and $8,000\;{\AA}$ by thermal evaporation. The adhesion between sample and Cu thin film improvement of treated PS surface against untreated sample. could be verifiable by Tape test (ASTM D3359)

• Journal of the Microelectronics and Packaging Society
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• v.6 no.2
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• pp.37-43
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• 1999

Modules of the system that requires large capacity and high-speed information processing are implemented in the form of MCM that allows high-speed data processing, high density circuit integration and widely applied to such fields as ATM, GPS and PCS. Hence we developed the ATM switching module that is consisted of three chips and 2.48 Gbps data throughput, in the form of 10 multi-layer by Cu/Photo-BCB and 491pin PBGA which size is $48 \times 48 \textrm {mm}^2$. hnologies required for the development of the MCM includes extracting parameters for designing the substrate/package through the interconnect characterization to implement the high-speed characteristics, thermal management at the high-density MCM, and the generation of the testability that is one of the most difficult issues for developing the MCM. For the development of the ATM Switching MCM, we extracted signaling delay, via characteristics and crosstalk parameters through the interconnect characterization on the MCM-D. For the thermal management of 15.6 Watt under the high-density structure, we carried out the thermal analysis. formed 1.108 thermal vias through the substrate, and performed heat-proofing processing for the entire package so that it can keep the temperature less than $85^{\circ}C$. Lastly, in order to ensure the testability, we verified the substrate through fine pitch probing and applied the Boundary Scan Test (BST) for verifying the complex packaging/assembling processes, through which we developed an efficient and cost-effective product.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.251-251
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• 2016

For several decades, industrial processes consume a huge amount of raw water for various objects that consequently results in the generation of large amounts of wastewater. Wastewaters are consisting of complex mixture of different inorganic and organic compounds and some of them can be toxic, hazardous and hard to degrade. These effluents are mainly treated by conventional technologies such are aerobic and anaerobic treatment and chemical coagulation. But, these processes are not suitable for eliminating all hazardous chemical compounds form wastewater and generate a large amount of toxic sludge. Therefore, other processes have been studied and applied together with these techniques to enhance purification results. These include photocatalysis, absorption, advanced oxidation processes, and ozonation, but also have their own drawbacks. In recent years, electrochemical techniques have received attention as wastewater treatment process that could be show higher purification results. Among them, boron doped diamond (BDD) attract attention as electrochemical electrode due to good chemical and electrochemical stability, long lifetime and wide potential window that necessary properties for anode electrode. So, there are many researches about high quality BDD on Nb, Ta, W and Si substrates, but, their application in effluents treatment is not suitable due to high cost of metal and low conductivity of Si. To solve these problems, Ti has been candidate as substrate in consideration of cost and property. But there are adhesion issues that must be overcome to apply Ti as BDD substrate. Al, Cu, Ti and Nb thin films were deposited on Ti substrate to improve adhesion between substrate and BDD thin film. In this paper, BDD films were deposited by hot filament chemical vapor deposition (HF-CVD) method. Prior to deposition, cleaning processes were conducted in acetone, ethanol, and isopropyl alcohol (IPA) using sonification machine for 7 min, respectively. And metal layer with the thickness of 200 nm were deposited by DC magnetron sputtering (DCMS). To analyze microstructure X-ray diffraction (XRD, Bruker gads) and field emission scanning electron microscopy (FE-SEM, Hitachi) were used. It is confirmed that metal layer was effective to adhesion property and improved electrode property. Electrochemical measurements were carried out in a three electrode electrochemical cell containing a 0.5 % H2SO4 in deionized water. As a result, it is confirmed that metal inter layer heavily effect on BDD property by improving adhesion property due to suppressing formation of titanium carbide.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.4
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• pp.345-353
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• 2007

We have obtained a topographical image nondestructively for a Cu thin film in liquid using a near-field scanning microwave microscope (NSMM), its operating frequency was 3.5 to 5.5 GHz. We have kept a distance of 10 nm between tip and sample using a quartz tuning fork shear force feedback system. As an end of tip was attached to one prong of the quartz tuning fork has a length of 2 mm, the only tip of tuning fork was immersed in water tank. A loss cause by evaporation in water tank is regulated with actuator was connected to a supplementary tank. Moreover, using a revise program of LabView, we could increase the accuracy of a measurement in liquid.