• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.305.2-305.2
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• 2016

Tin monosulfide (SnS) is one promising candidate absorber material which replace the current technology based on cadmium telluride (CdTe) and copper indium gallium sulfide selenide (CIGS) for its suitable optical band gap, high absorption coefficient, earth-abundant, non-toxic and cost-effective. During past years work, thin film solar cells based on SnS films had been improved to 4.36% certified efficiency. In this study, Tin monosul fide was obtained by atomic layer deposition (ALD) using the reaction of Tetrakis (dimethylamino) tin (TDMASn, [(CH3)2N]4Sn) and hydrogen sulfide (H2S) at low temperatures (100 to 200 oC). The direct optical band gap and strong optical absorption of SnS films were observed throughout the Ultraviolet visible spectroscopy (UV VIS), and the properties of SnS films were analyzed by sanning Electron Microscope (SEM) and X-Ray Diffraction (XRD).

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.6
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• pp.496-503
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• 2008

We propose rectangular type spiral coils with folded comers for the applications to low frequency guided wave magnetostrictive transducers and describe a method for making the proposed coils from insulated electrical wire such as enameled copper wire. Expressions for the electrical properties of the coils are also presented and compared with experimental measurements. An overlapped-2-channel folded-comer spiral-coil array is fabricated and applied to a magnetostrictive strip transducer generating and detecting fundamental torsional mode guided waves. From the results we conclude that the design and fabrication method make it possible to use the magnetostrictive transducers optimized for various guided wave applications and also will greatly help engineers gain easy access to the optimized transducers.

• Journal of the Korean Vacuum Society
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• v.15 no.1
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• pp.45-49
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• 2006

The changes in the optical anisotropy of the clean Cu(110) and the oxygen covered Cu(110) surfaces due to Cu growth have been studied by reflectance difference spectroscopy(RDS). We have monitored the growth mode of Cu atoms on Cu(110) and Cu(110)-(2XlO surfaces at 250K and checked the surfactant effect of oxygen during the Cu growth. For Cu grow on Cu(110) and Cu(110)-(2Xl)O surface at low temperature, we observed evidence for the layer-by-layer growth mode with change of 4.25eV peak intensity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.2
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• pp.107-111
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• 2018

In this study, we designed the temperature coefficient of resistance (TCR) and heat radiation properties of shunt fixed resistors by adjusting the atomic composition of a metal alloy resistor, and fabricated a resistor that satisfied the designed properties. Resistors with similar atomic composition of copper and nickel showed low TCR and excellent shunt fixed resistor properties such as short-time overload, rated load, humidity load, and high temperature load. Finally, we expect that improved sensor accuracy will be obtained in current-distribution-type shunt fixed resistor for IoT sensors by designing the atomic composition of the metal alloy resistor proposed in this work.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.145-146
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• 2012

Recently the problem of the fouling organisms, especially Sn-compounds is expanded to environmental problems from the chemical reaction with imposex and secondary contamination. One of the existing antifouling system, antifouling paints, is regulated from 2012, July because of seriousness about toxic substances such as TBT, mercury, copper and so on. TBT is known that causes a variety of biological inhibition in various chemicals even a very small amount of concentration. So it has been developed to replace it. In this paper, we try to develope a new system with the environmental background and the research of the adhesion characteristics of fouling organisms using a low current, high frequency high voltage pulse power, not toxic compounds.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.2
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• pp.23-29
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• 2014

Less power consumption, lower cost, smaller size and more functionality are the increasing demands for consumer electronic devices. The three dimensional(3-D) TSV packaging technology is the potential solution to meet this requirement because it can supply short vertical interconnects and high input/output(I/O) counts. Cu(Copper) has usually been chosen to fill the TSV because of its high conductivity, low cost and good compatibility with the multilayer interconnects process. However, the CTE mismatch and Cu ion drift under thermal stress can raise reliability issues. This study discribe the thermal stress reliability trend for successful implementation of 3-D packaging.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.29-33
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• 2001

The production of Secondary Non-ferrous Metals (SNM) is characterized by low investment, energy consumption and cost, less pollution as well as rather simple technology. In the past years, the SNM industry has seen relevantly rapid progress in China. Especially in the filed of clean hydrometallurgical treatment certain novel technologies for recovery and separation have successfully been elaborated, and a number of medium and small commercial plants established. On the basis of four common metals Cu, Al, Pb, Zn, and Ni, Co, this paper describes the status quo and progress of SNM industry in China, indicating that a lot of work should still be done in salvage of waste metals. It is recommended that measures for collecting and classifying SNM resource should be strengthened and the research on new technologies for scavenging such metals should be supported.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.537-537
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• 2008

Copper (Cu) has been widely used for interconnection structure in intergrated circuits because of its properties such as a low resistance and high resistance to electromigration compared with aluminuim. Damascene processing for the interconnection structure utilizes 2-steps chemical mechanical polishing(CMP). After polishing, the removal of abrasive particles on the surfaces becomes as important as the polishing process. In the paper, buffing process for the removal of colloidal silica from polished Cu wafer was proposed and demonstrated.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.370-371
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• 2006

The particulate strengthened $Cu-MoSi_2$ composites were prepared by a PM process to develop novel copper based composites with reasonable strength, high thermal conductivity and low thermal expansion coefficient. Microstructure of the composites was investigated by SEM; the tensile strength, elongation, thermal conductivity and thermal expansion coefficient (CTE) of the composites were examined. A comparative analysis of mechanical and thermal properties of various Cu-matrix composites currently in use was given and the strengthening mechanisms for the $Cu-MoSi_2$ composites were discussed.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1141-1143
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• 2005

This paper presents the reasonable design parameters of a SRM for hybrid electric vehicle driving. For the design of SRM, the initial model is designed using the equivalent magnetic circuit method. In order to optimize the SRM for HEV. The initial model is redesigned by FEM with the variation of the stock length and turns of winding. This paper shows that a flat-topped current of a phase can be made from a change of the stack length and the number of turns for high efficiency, high average torque and a lower torque ripple. The change of current falling time as a variation of turn-off angle was shown by FEA. The iron loss and copper loss were described. The torque of the redesigned motor is suitable for low and high speed ranges to drive a HEV that was verified by the speed-torque curve.