• 한국표면공학회지
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• 제24권1호
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• pp.25-30
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• 1991

The evaporation characteristics of Ag, Al, Au, Cr. Cu, In, Mg, Mn, Pb, Pd, Si, SiO, Sn, Ti and Zn with the various resistive heating sources have been studied. The employed sources are refractory metal (Mo, Ta and W) boats, W-wire, ceramic (usually Al2O3)-coated and -barriered refractory metal boats, and special boats such as baffled boats and intermetallic boats (nitride compound and graphite). We investigated the melting mode, evaporation rate at a specific power, and lifetime of the sources. A special boat holder is also discussed which is needed to cool the sources at a large heat capacity.

• 열처리공학회지
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• 제22권3호
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• pp.143-148
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• 2009

We have fabricated Ti metal films on Cu wire substrates by using a RF magnetron sputtering method at different RF powers (0, 30 and 60 W) in a high vacuum, and we have investigated the thin film characteristics and resistivity. The ion bombardment effect is increased by the method to superimpose RF power to DC power applied to two poles of the base; thus, the thin film is deposited at sputtering gas pressures below 1 Pa. Moreover, the thin film formation of the multilayer structure becomes possible by gradually injecting the RF power, and the thin film quality is improved.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.251-253
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• 2007

현재 다이아몬드 공구에서 극세선에 브레이징 공정을 이용하여 다이아몬드를 접합하는 기술은 국내외 적으로 전무한 상태이다. 이 연구는 금속 와이어에 다이아몬드를 브레이징을 실시하여 최적의 와이어 브레이징 공정법을 개발 하는데 있다. 다이아몬드와 금속필러메탈 접합 계면에서의 금속성분과 탄화물의 거동을 분석하며, 브레이징에 따른 와이어의 물성 변화를 관찰하였다. 금속필러로는 Ag-Cu-5Ti(wt.%)을 사용하였으며, 와이어는 스테인리스를 이용하였다. 브레이징 공정은 진공 접합 장치를 이용하여 $800{\sim}1000^{\circ}C$에서 유지시간 $5{\sim}30$분로 실시하였다. 브레이징된 다이아몬드는 $900{\sim}950$도, 유지시간 10분 사이에서 각각 건전한 계면과 표면을 얻을 수 있었으며, 계면에서 Ti-rich상과 화합물이 확인되었다. 또한 열처리 따른 와이어의 최적의 건전한 상태를 고찰 하였다. 다이아몬드와 Ag계 브레이징 필러의 계면에서의 미세조직 및 화학반응의 메커니즘은 SEM, EPMA, XRD를 이용하여 분석하였다.

• Journal of Electrical Engineering and information Science
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• 제2권3호
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• pp.77-81
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• 1997

In his work, the influence of wire type conducting particles on the insulation reliability of GIS has been systematically investigated when the epoxy resin based dielectric coating was made on he inner side of outer electrode. For this purpose, coaxial cylinder-type electrode was adopted in 362 kV chamber and various sizes of Cu conducting particle were used under different gas pressures. In order to elucidate the coating effect on the gas insulation, different thickness of dielectric coating has been considered and then the lift-off voltage and flashover voltages have been measured. The results shown that the dielectric coating has a remarkable influence by restraining the movement of particle in GIS system, and thus GIS insulation reliability is noticeably improved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1494-1496
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• 1997

The MRI Magnet is a most practical application of NbTi superconductor. In this paper, we present the main research results on superconducting wires for MRI magnet which we have developed. Cu/NbTi superconducting wires were fabricated by repeat of cold working and heat-treating process after that billets were extruded. We investigated the relation of superconductivities of wires and heat treatment condition. The correlation between cross section shape of wires and work inhomogeneity of NbTi rods was investigated by microscopic observation. The more repeatation number of cold working and heat-treating process, the higher critical current is achieved.

• 대한전기학회논문지
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• 제45권2호
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• pp.193-198
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• 1996

Low power superconducting persistent current switch(PCS) for the superconducting magnet systems in the persistent mode was developed and its experimental results were analyzed when the system was charged or discharged. The multifilament NbTi wire with Cu matrix was used for the PCS. The constructed NbTi superconducting switch with superconducting magnet system operated successfully. It also operated on-off switching action with good stabilization. The maximum operating current in persistent mode was 60A (at 1T). In persistent current mode, the decay of the persistent current at 60A was observed. Its decay was 3.55% in 60 min. It is possible to make the persistent current switch with the better decaying of persistent current if some problems for joint resistance are solved.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.288-291
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• 2001

It is very important to select suspension solution for forming electrophoretic deposited YBCO thick film, because it is heavily affected to its superconducting properties. In this paper, high-temperature superconductor films of YBa$_2$Cu$_3$$O_{7-x}$ were fabricated by electrophoretic deposition (EPD) from alcohol-based suspension such as iso-propanol, iso-butanol, and their mixture. For the formation of YBCO dense and adherent coating on a silver wire by EPD, 1% PEG(1000) 2 $m\ell$, as a additive for making their surface crack-free, was used for electrophoresis. As a results, the cracks were considerably decreased and the superconducting critical current density (J$_{c}$) without/with PEG was 1200 A/$\textrm{cm}^2$ and 2020 A/$\textrm{cm}^2$, which films deposited in mix ism-propanol and iso-butanol suspension.ion.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.267-269
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• 1996

In this work, the influence of wire type conducting particles on the insulation reliability of GIS has been systematically investigated when outer electrode was dielectric coated by epoxy resin. For this purpose, coaxial cylinder-type electrode was adopted in 362 kV chamber and various size of Cu conducting particle was used and different gas pressure was applied. To prove the coating effect on the gas insulation, different thickness of epoxy coated outer electrode have been considered and the lift-off voltage and flashover voltage have been analyzed. The results show that the dielectric coated electrode has an remarkable influence on the reducing particle behavior in GIS system and enhancing the GIS insulation reliability.

• 한국산업융합학회 논문집
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• 제12권4호
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• pp.215-219
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• 2009

A packaging technology based on flip-chip bonding and Pb-free solder for silicon pressure sensors on printed circuit board (PCB) is presented. First, the bump formation process was conducted by Pb-free solder. Ag-Sn-Cu solder and the pressed-screen printing method were used to fabricate solder bumps. The fabricated solder bumps had $189-223{\mu}m$ width, $120-160{\mu}m$ thickness, and 5.4-6.9 standard deviation. Also, shear tests was conducted to measure the bump shear strength by a Dage 2400 PC shear tester; the average shear strength was 74 g at 0.125 mm/s of test speed and $5{\mu}m$ shear height. Then, silicon pressure sensor packaging was implemented using the Pb-free solder and bump formation process. The characteristics of the pressure sensor were analogous to the results obtained when the pressure sensor dice are assembled and packaged using the standard wire-bonding technique.

• 자원리싸이클링
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• 제21권3호
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• pp.48-55
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• 2012

최근 친환경적이며 고효율적인 폐동선의 재활용을 위하여 다양한 방안이 모색되고 있는 실정이다. 본 연구에서는 폐동선의 고주파 유도가열을 이용하여 폐동선의 피복제거의 실험을 수행하여 폐동선의 친환경적이며 고효율의 재활용방안을 모색하고자 다양한 공정조건하에 최적화된 방안을 도출하였다. FT-IR 분석결과, 폐동선에 코팅된 물질은 polyester임이 나타났으며, 와전류의 전산모사결과, 최적화 과정을 도출하고 이에 대하여 논의하였다. 폐동선의 피복을 효과적으로 단시간에 분리하기 위하여 폐동선을 고주파 유도코일에 수직으로 장입하고 $950^{\circ}C$이상의 온도에서 유지해야 함을 알 수 있다.