• Title/Summary/Keyword: Organic PCB

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Risk Assessment of Polychrorinated Biphenyls (PCBs) through Food Intake for the Korean Population (식품 중 폴리염화비페닐 위해평가)

  • Paek, Ockjin;Suh, Junghyuk;Park, Heera;Oh, Keumsoon;Hong, Selyung;Lee, Hyunkyung;Kim, Meehye
    • Korean Journal of Food Science and Technology
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    • v.45 no.3
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    • pp.364-369
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    • 2013
  • Polychlorinated biphenyls (PCBs) have been studied during the past few decades because of their potential impacts on the environment and human health. PCBs are toxic environmental pollutants and persistent organic pollutants (POPs). This study was carried out to assess the dietary exposure and risk to PCBs for the general Korean population through food intake. Various samples (n=389) covering 28 kinds of food were collected from 5 cities in Korea. The PCB content was not detected-$182.4{\mu}g/kg$ (mean of $5.4{\mu}g/kg$) in the food. The mean dietary exposure of PCBs for the general population was 9.54 ng/kg bw/day with an intake of 0.19% of tolerable daily intake (TDI) ($5{\mu}g/kg$ bw/day). Therefore, the level of overall dietary exposure to PCBs for the Korean population through food intake is below the recommended TDI levels.

On the Harzadous Components of Paper Mill Sludge and Sludge Treated Soil (제지(製紙)슬러지와 슬러지 시용토양중(施用土壤中)의 유해성분(有害性分)에 관하여)

  • Lee, Kyu Seung;Choi, Jong Woo;Jo, Jeong Rye;Kim, Moon Kyu
    • Korean Journal of Agricultural Science
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    • v.19 no.2
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    • pp.194-200
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    • 1992
  • In order to use organic resource like a compost 44 samples of paper mill sludge were collected from each paper manufacturer. Some metal and PCBs(polychlorinated biphenyls) contents in/on sludge were investigated and metal contents of soil treated with kraft and paper board sludge were checked in contrast io the non-treated soil. The staple results were the same as followings. 1. Average contents of Pb in sludge ranged 14.5-25.7 ppm, and Al, Cd, Cu, Fe, Zn were similar concentration to unpolluted soil. Also, Cr and Hg were not detected from any sludge sample. 2. PCBs contents in sludge of kraft, paper board and news print paper were determined. Less than 10 ppb of $PCB_s$ contents were detected from kraft and paper board sludges, but a little more was found in sludge of news print paper. 3. Some metal contents in sludge treated soil were much similar to non-treated soil and the concentration also were ranged under the average of unpolluted natural soil. 4. From these results paper mill sludge seemed to be no harmful effects to soil.

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Effects of PCB Surface Finishes on Mechanical Reliability of Sn-1.2Ag-0.7Cu-0.4In Pb-free Solder Joint (PCB 표면처리에 따른 Sn-1.2Ag-0.7Cu-0.4In 무연솔더 접합부의 기계적 신뢰성에 관한 연구)

  • Kim, Sung-Hyuk;Kim, Jae-Myeong;Yoo, Sehoon;Park, Young-Bae
    • Journal of the Microelectronics and Packaging Society
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    • v.19 no.4
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    • pp.57-64
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    • 2012
  • Ball shear test was performed by test variables such as loading speed and annealing time in order to investigate the effect of surface finishes on the bonding strength of Sn-1.2Ag-0.7Cu-0.4In Pb-free solder. The shear strength increased and the ductility decreased with increasing shear speed. With increasing shear speed, the electroless nickel immersion gold (ENIG) finish showed dominant brittle fracture mode, while organic solderability preservative (OSP) finish showed pad open fracture mode. The shear strength and toughness for both surface finishes decreased with increasing annealing time under the high-speed shear test of 500 mm/s. Typically, the thickness of intermetallic compound increased with increasing annealing time, which means that exposure of brittle fracture became much easier. With increasing annealing time, the both ENIG and OSP finishes exhibited the pad open fracture mode. Overall, ENIG finish showed higher shear strength rather than OSP finish due to its superior barrier stability.

A Study on the Leaching of Heavy Metals by Municipal Solid Waste Landfill Leachate (폐기물 매립지 침출수에 의한 중금속 용출에 관한 연구)

  • Jung, Jong-Gwan;Jang, Won;Park, Young-Suk
    • Journal of Environmental Impact Assessment
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    • v.6 no.1
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    • pp.105-110
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    • 1997
  • Sanitary landfill is a general method as a final disposal of municipal solid waste(MSW), therefore leachate characteristics are very various as lime goes by because of highly concentrated organic acids are contained non biodegradable COD. So it is hard to abide by the mandatory standards of discharge eventhough applying the physicochemical and biological processes to treat the leachate. The process of treating leachate are determined by the degree of removal and components, but they are highly contained organic materials. It is a removal method to use jointly with the physicochemical process if the hard and fast rule is needed. The critical components of material are COD, ammonia, salts and heavy metals in the case of treating biologically. Biological process is to use metabolism of microorganism, therefore it is a desirable condition which heavy metals are not contained, because they acting as an inhibitor of enzyme. Of these are contained, organic decomposition and synthetic function of microorganisms decrease significantly. Consequently, this research paper lays emphasis on the concentration of heavy metals in leachate and for the purpose of forecasting the factors which are affecting the leaching of metalic waste in some degree, experimented the various reacting conditions. 1. When the concentration of heavy metals in leachate is in comparison with the level eluted after reaction, at pH 7.9 the result of reaction for PCB to CCL scrap showed that Zn, Mn, Cu was more eluted 11.6 times, 340.3 times, and 2,705.5 times respectively than the leachate undiluted solution. 2. At the condition of strong acid pH 4.7, the concentration of heavy metals in EM undiluted solution showed that Zn, Mn, Cu was more eluted 26.5 times, 147.3 times, and 3,656.3 times respectively than leachate undiluted solution. 3. When the ratio leachate to EM was 50 vs 50(V/V%), Mn was more eluted 198.7 times than leachate undiluted solution, but Zn and Cu do not show the meaningful results. 4. The color of landfill leachate was black-brown. And fulvic acid that is main ingredient of NBD COD contained, oxygen of 44~50%. For that reason, I estimated that the level of Zn, Mn, Cu was higher than the case of leachate. 5. COD of leachate from general landfill is difficult to remove. Because the solution of heavy metals is improved by the character of leachate(pH & ingredient of oxygen etc.) hence the Mn, Cu, Zn act as disturbing factor, the biochemical treatment is hard. Therefore the type of PCB & CCL scrap, iron, aluminum contained metals need to previously separate from general wastes as much as possible.

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Effects of Organic Additives on Residual Stress and Surface Roughness of Electroplated Copper for Flexible PCB

  • Kim, Jongsoo;Kim, Heesan
    • Corrosion Science and Technology
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    • v.6 no.4
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    • pp.154-158
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    • 2007
  • For the application of flexible printed circuit board (FPCB), electroplated copper is required to have low surface roughness and residual stress. In the paper, the effects of surface roughness and residual stress of electroplated copper as thick as $8{\mu}m$ were studied on organic additives such as inhibitor, leveler and accelerator. Polyimide film coated with sputtered copper was used as a substrate. Surface roughness and surface morphology were measured by 3D-laser surface analysis and FESEM, respectively. Residual stress was calculated by Stoney's equation after measuring radius curvature of specimen. The addition of additives except high concentration of accelerator in the electrolyte decreased surface roughness of electroplated copper film. Such a tendency was explained by the function of additives among which the inhibitor and the leveler inhibit electroplating on a whole surface and prolusions, respectively. The accelerator plays a role in accelerating the electroplating in valley parts. The inhibitors and the leveler increased residual stress, whereas the accelerator decreased it. It was thought to be related with entrapped additives on electroplated copper film rather than the preferred orientation of electroplated copper film. The reason why additives lead to residual stress remains for the future work.

Design and Fabrication of Low Temperature Processed $BaTiO_3$ Embedded Capacitor for Low Cost Organic System-on-Package (SOP) Applications (저가형 유기 SOP 적용을 위한 저온 공정의 $BaTiO_3$ 임베디드 커페시터 설계 및 제작)

  • Lee, Seung-J.;Park, Jae-Y.;Ko, Yeong-J.
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1587-1588
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    • 2006
  • Tn this paper, PCB (Printed Circuit Board) embedded $BaTiO_3$ MIM capacitors were designed, fabricated, and characterized for low cost organic SOP applications by using 3-D EM simulator and low temperature processes. Size of electrodes and thickness of high dielectric films are optimized for improving the performance characteristics of the proposed embedded MIM capacitors at high frequency regime. The selected thicknesses of the $BaTiO_3$ film are $12{\mu}m$, $16{\mu}m$, and $20{\mu}m$. The fabricated MIM capacitor with dielectric constant of 30 and thickness of $12{\mu}m$ has capacitance density of $21.5p\;F/mm^2$ at 100MHz, maximum quality factor of 37.4 at 300 MHz, a quality factor of 30.9 at 1GHz, self resonant frequency of 5.4 GHz, respectively. The measured capacitances and quality factors are well matched with 3-D EM simulated ones. These embedded capacitors are promising for SOP based advanced electronic systems with various functionality, low cost, small size and volume.

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Study of Peel Strength Property of Aluminum/Organic Composite (알루미늄/유기물 복합재료의 Peel 강도 특성에 대한 연구)

  • Kim, Jun-Young;Yoo, Myong-Jae;Kim, Seoung-Taek;Lee, Woo-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.217-218
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    • 2007
  • Aluminum 분말과 고분자를 혼합하여 고분자-금속 복합재료(polymer-metal composite)를 만들어 copper foil과 기판의 접착력을 평가하였다. Tape casting 방법을 이용하여 sheet 만들고 vacuum lamination으로 PCB(Printed Circuit Board)기판을 제조한 후 포토공정으로 peel strength pattern을 형성하였으며, 본 연구에서는 최적의 aluminum 조건을 찾기 위하여 압력, 온도, copper foil의 표면 상태와 silane 표면 코팅에 따른 aluminum-polymer복합재료의 peel strength의 변화를 확인하였다. 최적의 조건은 silane 표면 코팅 처리를 한 aluminum 분말로 $210^{\circ}C$에서 $9.7kg/cm^2$ 압력으로 matte면의 돌기 크기가 크며, 응집이 잘 되어있는 copper foil을 사용하여 13.89N의 우수한 peel strength를 구현 할 수 있었다.

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Development of Atmospheric Pressure Plasma Equipment and It's Application to Flip Chip BGA Manufacturing Process (대기압 플라즈마 설비 개발 및 Flip Chip BGA 제조공정 적용)

  • Lee, Ki-Seok;Ryu, Sun-Joong
    • Journal of the Semiconductor & Display Technology
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    • v.8 no.2
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    • pp.15-21
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    • 2009
  • Atmospheric pressure plasma equipment was successfully applied to the flip chip BGA manufacturing process to improve the uniformity of flux printing process. The problem was characterized as shrinkage of the printed flux layer due to insufficient surface energy of the flip chip BGA substrate. To improve the hydrophilic characteristics of the flip chip BGA substrate, remote DBD type atmospheric pressure plasma equipment was developed and adapted to the flux print process. The equipment enhanced the surface energy of the substrate to reasonable level and made the flux be distributed over the entire flip chip BGA substrate uniformly. This research was the first adaptation of the atmospheric pressure plasma equipment to the flip chip BGA manufacturing process and a lot of possible applications are supposed to be extended to other PCB manufacturing processes such as organic cleaning, etc.

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Cloning and Phylogenetic Analysis of Two Different bphC Genes and bphD Gene From PCB-Degrading Bacterium, Pseudomonas sp. Strain SY5

  • Na, Kyung-Su;Kim, Seong-Jun;Kubo, Motoki;Chung, Seon-Yong
    • Journal of Microbiology and Biotechnology
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    • v.11 no.4
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    • pp.668-676
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    • 2001
  • Pseudomonas sp. strain SY5 is a PCB-degrading bacterium [24] that includes two different enzymes (BphC1 and BphC2) encoding 2,3-dihdroxybiphenyl 1,2-dioxygenase and BphD encoding 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase. The bphC1 and bphC2 genes were found to consist of 897 based encoding 299 amino acids and 882 bases encoding 294 amino acids, respectively, whereas the bphD gene consisted of 861 bases encoding 287 amino acids. According to a homology search, a 50% and 39% similarity between the bphC1 and bphC2 genes at the nucleotide and amino acid level was shown, respectively. The bphC1 gene showed a 38% and 45% similarity at the amino acid level to Alcaligenes eutrophus A5 and Rhodococcus rhodochrous, respectively, whereas, bphC2 showed a 95% and 43% similarity, respectively. A comparison of the deduced amino acid sequence of the bphD product of Pseudomonas sp. SY5 with that of A. eutrophus A5, Pseudomons sp. KKS102, and LB400 showed a sequence identity of 92, 92, and 79%, respectively. Strain SY5 was originally isolated from municipal sewage containing recalcitrant organic compounds an found to have a high degradability of various aromatic compounds [23]. The current study found that strain SY5 had two extradiol-type dioxygenases, which did not hybridize with each other as they had a low similarity, yet a similar structure of evolutionarily conserved amino acids residues for catalytic activity between BphC1 and BphC2 was observed.

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Effect of Applied Voltage Bias on Electrochemical Migration in Eutectic SnPb Solder Alloy

  • Lee, Shin-Bok;Jung, Ja-Young;Yoo, Young-Ran;Park, Young-Bae;Kim, Young-Sik;Joo, Young-Chang
    • Corrosion Science and Technology
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    • v.6 no.6
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    • pp.282-285
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    • 2007
  • Smaller size and higher integration of electronic systems make narrower interconnect pitch not only in chip-level but also in package-level. Moreover electronic systems are required to operate in harsher conditions, that is, higher current / voltage, elevated temperature / humidity, and complex chemical contaminants. Under these severe circumstances, electronic components respond to applied voltages by electrochemically ionization of metals and conducting filament forms between anode and cathode across a nonmetallic medium. This phenomenon is called as the electrochemical migration. Many kinds of metal (Cu, Ag, SnPb, Sn etc) using in electronic packages are failed by ECM. Eutectic SnPb which is used in various electronic packaging structures, that is, printed circuit boards, plastic-encapsulated packages, organic display panels, and tape chip carriers, chip-on-films etc. And the material for soldering (eutectic SnPb) using in electronic package easily makes insulation failure by ECM. In real PCB system, not only metals but also many chemical species are included. And these chemical species act as resources of contamination. Model test systems were developed to characterize the migration phenomena without contamination effect. The serpentine-shape pattern was developed for analyzing relationship of applied voltage bias and failure lifetime by the temperature / humidity biased(THB) test.