• Title/Summary/Keyword: Organic PCB

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Investigation on Fabrication Process and Tolerance of Resistance Body with A Uniform Thickness Shape on Organic Substrate for Application of Embedded Resistor (Embedded Resistor 적용을 위한 Organic 기판 위에 균일한 두께의 형상을 갖는 저항체의 제조공정과 편차에 대한 조사)

  • Park, Hwa-Sun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.4
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    • pp.72-77
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    • 2008
  • This paper investgated on fabrication process and tolerance of resistance body with a uniform thickness formed by the process of cavity type on organic substrate for application of embedded resistor. To improve the tolerance of resistance value according to a position of PCB cause by conventional screen printing, we introduced the process of cavity type from organic substrate. A resistor with a desired shape and volume was precisely formed by the process of cavity using a resistor paste and screen printing. This method can increase PCB's productivity by shortening its production time because process conditions of a screen prining device can be set quickly without any affection on its position accuracy.

Global Fate of Persistent Organic Pollutants: Multimedia Environmental Modelling and Model Improvement (잔류성 유기오염물질의 전 지구적 거동: 다매체 환경모델의 결과해석 및 개선방안)

  • Choi, Sung-Deuk;Chang, Yoon-Seok
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.1
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    • pp.24-31
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    • 2007
  • Global fates of polychlorinated biphenyl(PCB) were investigated with a fugacity based multimedia transport and fate model, Globe-POP(persistent organic pollutant). The accumulation of PCB was directly affected by the emission patterns of PCB into the atmosphere and surface areas of environmental compartments. Partition coefficients and reaction rates also influenced on the accumulation patterns of PCB. The emission patterns of PCB in 10 climate zones were consistent for the past 70 years, while the contribution of PCB in high-latitude zones to the globe has increased by cold condensation. Considering the amounts of emission and accumulation of PCB, the North temperature zone is regarded as an important source and sink of PCB. Meanwhile, in spite of no significant sources, POPs accumulate in Antarctic environments mainly due to extremely low temperature. Finally we suggested that a global water balance accounting for snow/ice should be incorporated into multimedia environmental models for high-latitude zones and polar regions with the seasonal snow pack and/or permanent ice caps. The modified model will be useful to evaluate the influence of climate change on the fate of POPs.

Complete Decomposition of Chlorinated-Organic Compounds(PCB, 4-DCBz) with Improved Supercritical Water Oxidation Method (개량된 초임계수 산화법에 의한 염소계 유기물(PCB, 4-DCBz)의 완전분해반응)

  • Lee Sang-Hwan;Park Ki-Chul;Park Yoon-Yul;Yang Jong-Gyu;Kim Jung-Sung;Hiroshi Tomiyasu
    • Journal of Environmental Science International
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    • v.14 no.5
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    • pp.513-520
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    • 2005
  • For the destruction of toxic chlorinated organic compounds, this study proposes improved supercritical water oxidation method (multistep oxidation) using sodium nitrate as an oxidizer. This method solves the problems involved in the existing supercritical water oxidation method. Multistep oxidation means that $NaNO_3$ is oxidized to $N_2\;via\;NaNO_2$ and NO. Toxic and hard to destroy organic substances like para-dichlorobenzen(4-DCBz), polychlorinate biphenyl(PCB) ware oxidized to non toxic substances in a condition, in which rapid pressure and temperature rise is restrained as much as possible. 4-dichlorobenzene(4-DCBz) and Polychlorinate biphenyl(PCB) in condition$(450^{\circ}C,\;p_w=0.25g/cm^3,\;30min)$ Was discomposed perfectly.

Effects of Dissolved Humic Acid on Complexation and Activate Carbon Adsorption of PCB (Humic Acid가 PCB의 착화합과 활성탄 흡착특성에 미치는 영향)

  • Kim, Sung-Hyun;Beak, Il-Hyun
    • Applied Chemistry for Engineering
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    • v.4 no.4
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    • pp.746-752
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    • 1993
  • Quantitative measurements have been made by using equilibrium dialysis techniques on the extent of complexation between PCB and dissoved humic acid(HA). This research investigates the effectiveness of activated carbon adsorption for the removal of PCB from organic free water and humid acid background solution by using bench-scale equilibrium and rate tests. It was found that the extent of complexation depended on the pH, calcium concentration, ionic strength, and the concentration of humic acid. When HA was present, activated carbon capacity was greatly reduced due to complexation and competitive adsorption effects and the adsorption characteristics became complicated by the presence of various species such as the unassociated HA, PCB, and PCB-HA complexes.

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Flip Chip Assembly on PCB Substrates with Coined Solder Bumps (코인된 솔더 범프를 형성시킨 PCB 기판을 이용한 플립 칩 접속)

  • 나재웅;백경욱
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2002.11a
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    • pp.21-26
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    • 2002
  • Solder flip chip bumping and subsequent coining processes on PCB were investigated to solve the warpage problem of organic substrates for high pin count flip chip assembly by providing good co-planarity. Coining of solder bumps on PCB has been successfully demonstrated using a modified tension/compression tester with height, coining rate and coining temperature variables. It was observed that applied loads as a function of coined height showed three stages as coining deformation : (1) elastic deformation at early stage, (2) linear increase of applied load, and (3) rapid increase of applied load. In order to reduce applied loads for coining solder bumps on PCB, effects of coining process parameters were investigated. Coining loads for solder bump deformation strongly depended on coining rates and coining temperatures. As coining rates decreased and process temperature increased, coining loads decreased. Among the effect of two factors on coining loads, it was found that process temperature had more significant effect to reduce applied coining loads during the coining process. Lower coining loads were needed to prevent substrate damages such as micro-via failure and build-up dielectric layer thickness change during applying loads. For flip chip assembly, 97Pb/Sn flip chip bumped devices were successfully assembled on organic substrates with 37Pb/Sn coined flip chip bumps.

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Letters on Innoxious Treatment of Recalcitrant Nobiodegrable PCB Using Supercritical Method(1) (초임계법을 이용한 난분해성 유해물질인 폴리염화비폐닐(PCB)의 무해화 처리에 관한 총설(1))

  • 김정성;박윤열;김성윤
    • Journal of Environmental Science International
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    • v.9 no.6
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    • pp.523-529
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    • 2000
  • Attempts have been made to use Supercritical fluids for industrial purpose in a variety of fields and some of them, are already in practice. However, basic chemical properties of supercritical fluids have not been understood well. The present pater presents the results of physicochemical studies on Supercritical fluids as well as the application of supercritical fluids to industry. The detail is as follows PCB and organic compounds.

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Viscosity Change of Al2O3-SiO2-CaO Slag System with Used Electronic Scrap (산화처리된 PCB 스크랩을 첨가한 Al2O3-SiO2-CaO 3성분계 슬래그의 점도)

  • Kwon, Eui-Hyuk;Han, Sin-Suk;Ji, Jae-Hong;Han, Jeong-Whan;You, Byung-Don;Kim, Byung-Soo;Lee, Jae-Chun
    • Korean Journal of Materials Research
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    • v.13 no.4
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    • pp.239-245
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    • 2003
  • In order to explore the possibility to extract precious metals from PCB(Printed Circuit Board) scrap by gravity separation, a high temperature melting process was adopted, from the recycling view point, to investigate the influence of viscosity on A1$_2$$O_3$-CaO$-SiO_2$ slag system composed of PCB scrap. For optimizing the pre-treatment process of PCB scrap, an experimental condition for the complete calcination and oxidation of organic materials in PCB scrap was established and a quantitative analysis of oxidized PCB scrap was also carrie out. It was found that 6 hours were enough for the complete oxidation of PCB scrap at 1273 K in an atmosphere condition. A slag, l5wt%$A1_2$$O_3$-45wt%CaO-40wt%SiO$_2$, was chosen as a basic slag composition which is determined based on the quantitative analysis of PCB scrap. Viscosities were measured in slag systems both made from pure fluxes and from PCB scrap with additional fluxes. Slag viscosities composed of pure fluxes were measured to be 5.29 poise and 30.52 poise at temperatures of 1773 and 1573 K, whereas that of PCB scrap with additional fluxes were 3.37 poise and 69.89 poise, respectively.

Year-round Monitoring of Atmospheric Polychlorinated Biphenyls (PCBs) at the King Sejong Station in the Antarctic (남극 세종기지에서의 대기 중 PCB 모니터링)

  • Choi, Sung-Deuk;Baek, Song-Yee;Chang, Yoon-Seok;Yoon, Young-Jun;Park, Byong-Kwon;Hong, Sung-Min
    • Ocean and Polar Research
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    • v.29 no.4
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    • pp.297-302
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    • 2007
  • Atmospheric levels of polychlorinated biphenyls (PCBs) at the King Sejong station were monitored for one year using passive air samplers. Low-chlorinated PCB homologues were predominant in all samples. PCB levels were observed to decrease with distance from the station, which may indicate that a significant part of PCBs could be of local origin. Although the level of PCBs at the King Sejong station is very low (${\Sigma}_9PCB$ (18, 52, 101, 118, 128, 138, 153, 180, 187): $2.3\;pg\;m^{-3}$) probably due to decrease in the global PCB emissions, it is one order of magnitude higher than a background level in the Antarctic. Based on this preliminary study, more interpretation on PCB data and meteorological conditions is required.

A study on the Additive Decomposition Generated during the Via-Filling Process (Via-Filling 공정시 발생하는 첨가제 분해에 관한 연구)

  • Lee, Min Hyeong;Cho, Jin Ki
    • Journal of the Korean institute of surface engineering
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    • v.46 no.4
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    • pp.153-157
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    • 2013
  • The defect like the void or seam is frequently generated in the PCB (Printed Circuit Board) Via-Filling plating inside via hole. The organic additives including the accelerating agent, inhibitor, leveler, and etc. are needed for the copper Via-Filling plating without this defect for the plating bath. However, the decomposition of the organic additive reduces the lifetime of the plating bath during the plating process, or it becomes the factor reducing the reliability of the Via-Filling. In this paper, the interaction of each organic additives and the decomposition of additive were discussed. As to the accelerating agent, the bis (3-sulfopropyl) disulfide (SPS) and leveler the Janus Green B (JGB) and inhibitor used the polyethlylene glycol 8000 (PEG). The research on the interaction of the organic additives and decomposition implemented in the galvanostat method. The additive decomposition time was confirmed in the plating process from 0 Ah/l (AmpereHour/ liter) to 100 Ah/l with the potential change.