• Title/Summary/Keyword: ZnO blocks

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Changes of Electrical Characteristics of Arrester Blocks by a Multiple-lightning Impulse Current (다중 뇌충격전류에 의한 피뢰기 소자의 전기적 특성 변화)

  • Lee, J.H.;Cheon, S.G..;Kim, I.K.;Han, J.S.;Kil, G.S.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.2035-2037
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    • 2000
  • This paper describes the effect of lightning impulse current on deterioration of ZnO blocks for distribution arrester. In this study. a multiple-lightning impulse current generator which can produce quadruple 8/20 ${\mu}s$ 5 kA is designed and fabricated, and total energy applied to the arrester block at each pulse is about 1,217 J. The experimental results indicate that the type of arresters are more vulnerable to deteriorate or damage at multiple-lightning impulse current.

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Development of Transfer Method for Transparent Thin Film Transistor of Heat-treated Zinc Oxide Thin Film by Solution Process (용액공정을 이용한 열처리된 산화아연 박막의 투명한 박막 트랜지스터 구현을 위한 전사방법 개발)

  • Kwon, Soon Yeol;Jung, Dong Geon;Choi, Young Chan;Lee, Jae Yong;Kong, Seong Ho
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.2
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    • pp.57-60
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    • 2018
  • Recently, Thin-film transistors (TFTs) are fundamental building blocks for state-of-the-art microelectronics, such as flat-panel displays and system-on-glass. Zinc oxide thin films have the advantage that they can grow at low temperature and can obtain high charge movility. Also the zinc oxide thin film can be used to control the resistance according to the oxygen content, so it is very easy to obtain the desired physical properties. In this paper, we fabricated a zinc oxide thin film on a polished copper substrate through a solution process, then improved the crystallinity through a geat treatment porcess, and studied to transfer it on a flexible substrate after the heat treatment was completed.

Improvement in the negative bias stability on the water vapor permeation barriers on Hf doped $SnO_x$ thin film transistors

  • Han, Dong-Seok;Mun, Dae-Yong;Park, Jae-Hyeong;Gang, Yu-Jin;Yun, Don-Gyu;Sin, So-Ra;Park, Jong-Wan
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.110.1-110.1
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    • 2012
  • Recently, advances in ZnO based oxide semiconductor materials have accelerated the development of thin-film transistors (TFTs), which are the building blocks for active matrix flat-panel displays including liquid crystal displays (LCD) and organic light-emitting diodes (OLED). However, the electrical performances of oxide semiconductors are significantly affected by interactions with the ambient atmosphere. Jeong et al. reported that the channel of the IGZO-TFT is very sensitive to water vapor adsorption. Thus, water vapor passivation layers are necessary for long-term current stability in the operation of the oxide-based TFTs. In the present work, $Al_2O_3$ and $TiO_2$ thin films were deposited on poly ether sulfon (PES) and $SnO_x$-based TFTs by electron cyclotron resonance atomic layer deposition (ECR-ALD). And enhancing the WVTR (water vapor transmission rate) characteristics, barrier layer structure was modified to $Al_2O_3/TiO_2$ layered structure. For example, $Al_2O_3$, $TiO_2$ single layer, $Al_2O_3/TiO_2$ double layer and $Al_2O_3/TiO_2/Al_2O_3/TiO_2$ multilayer were studied for enhancement of water vapor barrier properties. After thin film water vapor barrier deposited on PES substrate and $SnO_x$-based TFT, thin film permeation characteristics were three orders of magnitude smaller than that without water vapor barrier layer of PES substrate, stability of $SnO_x$-based TFT devices were significantly improved. Therefore, the results indicate that $Al_2O_3/TiO_2$ water vapor barrier layers are highly proper for use as a passivation layer in $SnO_x$-based TFT devices.

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Palaeomagnetism of Cretaceous Rocks in the Ǔisǒng Area, Kyǒngsang Basin, Korea (의성지역 백악기 암석에 대한 고자기 연구)

  • Kim, In-Soo;Lee, Hyun Koo;Yun, Hyesu;Kang, Hee-Cheol
    • Economic and Environmental Geology
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    • v.26 no.3
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    • pp.403-420
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    • 1993
  • The Cretaceous Kyongsang Basin is known to be composed of several tectonic blocks (or subbasins) with each distinct stratigraphic succession. The study area represents a major part of one of these blocks, i. e. the $\check{U}is\check{o}ng$ block. The area is charaterized by a suite of WNW-trending sinistral strike-slip faults as well as a number of ring faults. A total of 292 independently oriented core samples were drilled from 23 sites, covering virtually all the formations of the Cretaceous $Ky\check{o}ngsang$ Supergroup. Alternating field and thermal demagnetization experiments were conducted to reveal the primary magnetization. Due to the homoclinal nature of the strata in the area, it was not possible to make use of the conventional fold test It is, however, believed that the primary remanent components have been obtained from the majority of the formations, considering the similarity of the palaeomagnetic pole positions with those of contemporary strata of other blocks and the existence of antiparallel reversed remanence. It was found neither any significant difference in magnetic declination on each side of the strike-slip faults nor systematic change of magnetic declination with distance from the fault-line. This does not support such a block rotation hypothesis associated with the strike-slip faulting in the area as alleged by some authors. The samples from the outcrops on or near the fault-lines were severely overprinted by the recent magnetic fields regardless of age and lithology. Epithermal Au-Ag-Cu-Pb-Zn mineralizations are known along some fault lines in the area. It is interpreted that these two facts are closely related with fluid circulations along the fracture zones caused by fault activities. In regard to the age of the strata as deduced from the magnetostratigraphic consideration, the $Ch\check{o}mgok$ formation and the lower strata should be older than Barremian or 124 Ma. The age of volcanics of the $Yuch^{\prime}\check{o}n$ Group sampled in this study should be younger than Campanian or 83 Ma.

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Temperature Characteristics with Structure of 18kV Lightning Arresters for Distribution System (18kV 배전용 피뢰기의 구조에 따른 온도특성)

  • Cho, Han-Goo;Yoon, Han-Soo;Lee, Un-Yong;Kim, Suk-Sou;Choi, In-Hyuk
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.1125-1128
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    • 2004
  • This paper presents the temperature characteristics with structure of 18 kV lightning arresters for distribution. Three types of polymer arresters were fabricated and ceramic type arrester was also ready to investigate. Below $100^{\circ}C$, three types of polymer arresters exhibited almost the same leakage current value, but above $100^{\circ}C$, polymer arrester that arrester module was injected into polymer housing with grease exhibited the highest leakage current and the arrester with the lowest leakage current was the arrester that silicon rubber was directly injected to arrester module. The rising of leakage current of polymer arrester with grease was because of existing grease between FRP winding and silicon housing, and reducing the insulation characteristics of the grease. All polymer arresters exhibited the same temperature characteristics but ceramic typr arrester was slower than polymer arrester in heat emission despite lowest leakage current. It was thought that the air layer between ZnO varistor blocks and ceramic housing prevented the heat emission. However, in spite of the difference of the structure, the variation of the surface temperature of all arresters exhibited the same result.

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Temperature and Leakage Current Characteristics with Structure of Polymeric Surge Arresters (폴리머 피뢰기의 구조에 따른 온도와 누설전류 특성)

  • Cho, Han-Goo;Lee, Un-Yong;Kim, Ha-Na
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.513-514
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    • 2006
  • This paper presents the temperature characteristics with the structure of 18 kV surge arresters for distribution system. Three types of polymer arrester were fabricated and a ceramic arrester was also prepared to investigate. Below $100^{\circ}C$, three types of polymeric arresters exhibited almost the same leakage current value, but above $100^{\circ}C$, the polymeric arresters whose module was injected into polymeric housing with the grease exhibited the highest leakage current. In contrary, the arresters being manufactured by directly injecting silicone rubber onto arrester module exhibited the lowest leakage current. The rapid rising of leakage current of the polymeric arresters with the grease at $120^{\circ}C$ was because of the deterioration of the insulation characteristics of the grease between the FRP module and the silicone housing. All polymeric arresters exhibited the same surface temperature characteristics but the ceramic arresters was slower than the polymer arrester in heat emission despite the lowest leakage current. It was thought that the air layer between ZnO varistor blocks and the ceramic housing prevented the heat emission.

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