• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.05a
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• pp.234-238
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• 1995

In this parer, by means of adding nonsuperconductive phase sliver into YBCO matrix, the superconductivity of Melted Texture Growth (MTG) YBa$_2$Cu$_3$O$\_$7-x/ was improved remarkably. In order to eliminate the crack inthe YBCO and the weak linkin the grain boundary, Ag contents from 2wt% to 18Wt% were doped in the YBCO It was found that J$\_$c/ of YBCO increase with the increasing Ag content till 14 wt% over 14wt% of Ag content, the Jc tends to stable . The grain size of YBCO became fine when Ag was added in the YBCO and X-ray diffraction showed that the YBCO crystal prepared by the above technique had (001) orientation and growing plane of YBCO was a-b plane. Using Bens medel, the J$\_$c/ was calculated and the best result was J$\_$c/ 76000A$\textrm{cm}^2$(77K, 100Gs).

• Proceedings of the KWS Conference
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• 2007.11a
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• pp.235-237
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• 2007

In this paper, fabrication of Sn-3.0Ag-0.5Cu solder bumping having accurate composition and behavior of intermetallic compounds(IMCs) growth at interface between Sn-Ag-Cu bumps and Cu substrate were studied. The ternary alloy of the Sn-3.0Ag-0.5Cu solder was made by two binary(Sn-Cu, Sn-Ag) electroplating on Cu pad. For the manufacturing of the micro-bumps, photo-lithography and reflow process were carried out. After reflow process, the micro-bumps were aged at $150^{\circ}C$ during 1 hr to 500 hrs to observe behavior of IMCs growth at interface. As a different of Cu contents(0.5 or 2wt%) at Sn-Cu layer, behavior of IMCs was estimated. The interface were observed by FE-SEM and TEM for estimating of their each IMCs volume ratio and crystallographic-structure, respectively. From the results, it was found that the thickness of $Cu_3Sn$ layer formed at Sn-2.0Cu was thinner than the thickness of that layer be formed Sn-0.5Cu. After aging treatment $Cu_3Sn$ was formed at Sn-0.5Cu layer far thinner.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.3
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• pp.45-51
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• 2013

Thermal annealing tests were performed in an in-situ scanning electron microscope chamber at $130^{\circ}C$, $150^{\circ}C$, and $170^{\circ}C$ in order to investigate the effects of solder structure on the growth kinetics of intermetallic compound (IMC) in Cu/Sn-3.5Ag microbump. Cu/Sn-3.5Ag($6{\mu}m$) microbump with spreading solder structure showed $Cu_6Sn_5$ and $Cu_3Sn$ phase growths and then IMC phase transition stages with increasing annealing time. By the way, Cu/Sn-3.5Ag($4{\mu}m$) microbump without solder spreading, remaining solder was transformed to $Cu_6Sn_5$ right after bonding and had only a phase transition of $Cu_6Sn_5$ to $Cu_3Sn$ during annealing. Measured activation energies for the growth of the $Cu_3Sn$ phase during the annealing were 0.80 and 0.71eV for Cu/Sn-3.5Ag($6{\mu}m$) and Cu/Sn-3.5Ag($4{\mu}m$), respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.2081-2086
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• 2015

Gecko is a kind of traditional Chinese medicine with remarkable antineoplastic activity. However, undefined mechanisms and ambiguity regarding active ingredients limit new drug development from gecko. This study was conducted to assess anti-angiogenic properties of the aqueous extracts of fresh gecko (AG) or macromolecular components separated from AG (M-AG). An enzyme-linked immunosorbent assay (ELISA) approach was applied to detect the vascular endothelial growth factor (VEGF) secretion of the tumor cells treated with AG or M-AG. The effect of AG or M-AG on vascular endothelial cell proliferation and migratory ability was analyzed by tetrazolium dye colorimetric method, transwell and wound-healing assays. Chick embryo chorioallantoic membrane (CAM) assays were used to ensure the anti-angiogenic activity of M-AG in vivo. The results showed that AG or M-AG inhibited the VEGF secretion of tumor cells, the relative inhibition rates of AG and M-AG being 27.2% and 53.2% respectively at a concentration of $20{\mu}L/mL$. AG and M-AG inhibited the vascular endothelial (VE) cell proliferation with IC50 values of $11.5{\pm}0.5{\mu}L/mL$ and $12.9{\pm}0.4{\mu}L/mL$ respectively. The VE cell migration potential was inhibited significantly (p<0.01) by the AG (${\geq}24{\mu}L/mL$) or M-AG (${\geq}12\mu}L/mL$) treatment. In vivo, neovascularization of CAM treated with M-AG was inhibited significantly (p<0.05) at a concentration of ${\geq}0.4{\mu}L/mL$. This study provided evidence that anti-angiogenesis is one of the anti-tumor mechanisms of AG and M-AG, with the latter as a promising active component.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3261-3264
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• 2013

Carbon nanocomposites composed of carbon nanostructures and metal nanoparticles have become one of useful materials for various applications. Here we present the preparation and antibacterial activity of CNT-Ag and GO-Ag nanocomposites. Their physical properties were characterized by TEM, XPS, and Raman measurements, revealing that size-similar and quasi-spherical Ag nanoparticles were anchored to the surface of the CNT and GO. The antibacterial activities of CNT-Ag and GO-Ag were investigated using the growth curve method and minimal inhibitory concentrations against Gram-negative and Gram-positive bacteria. The antibacterial activities of the carbon nanocomposites were slightly different against Gram-positive and Gram-negative bacteria. The proposed mechanism was discussed.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.640-640
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• 2013

본 연구에서는 유리 기판과 Si 기판에 Ag-doped ZnO 나노로드를 수열합성법을 이용하여 성장하였다. ZnO는 UV 영역에서 exciton 발광을 하며, 가시광선에서도 발광을 하는 것으로 알려져 있다. 그리고 Ag 금속은 입자형태로 ZnO 박막에 도포되었을 때 UV영역의 발광 세기를 강화시킨다는 사실이 알려져 있다. 이러한 내용을 바탕으로 ZnO 나노로드 합성 용액에 Ag powder의 양을 변화시켜 첨가하고, 유리와 Si기판을 넣고 80도에서 30분간 성장하였다. XRD, XPS를 통해 구조적 특성 변화를 보았고 SEM을 통해 나노로드의 형태를 확인하였다. 또한 PL, 투과도 측정을 통해 Ag 도핑에 따른 광학적 특성 변화를 확인하였다. SEM 측정으로 샘플의 단면을 확인한 결과 Ag 도핑 농도에 따른 차이가 거의 없음을 알았다. ZnO 나노로드가 성장된 유리 기판은 본래의 유리기판보다 투과도가 높았으며, Ag를 많이 첨가할수록 투과도가 낮아졌다.

• Proceedings of the KWS Conference
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• v.43
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• pp.25-27
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• 2004

• Proceedings of the KWS Conference
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• 2001.05a
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• pp.271-272
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• 2001

• Proceedings of the KWS Conference
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• 2001.05a
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• pp.277-278
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• 2001

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.2
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• pp.94-98
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• 2017

In the past few years, Sn-3.0Ag-0.5Cu (weight%) solder composition has been a representative material to electronic industries as a replacement of Pb-base solder alloy. Therefore, extensive studies on process and/or reliability related with the composition have been reported. However, recent rapid rise in Ag price has demanded solder compositions of low Ag content. In this study, Sn-3.0Ag-0.5Cu solder bar sample was fabricated by melting of Sn, Ag and Cu metal powders. Crystal structure and element concentration were analyzed by XRD, optical microscope, FE-SEM and EDS. The Sn-3.0Ag-0.5Cu solder sample was composed of ${\beta}$-Sn, ${\varepsilon}-Ag_3Sn$ and ${\eta}-Cu_6Sn_5$ phases.