• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2333-2337
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• 2007

The practical studies on the method of particle contamination control for yield enhancement in the cleanroom were carried out. The method of the contamination control was considered, which is composed of data collection, data analysis, improvement action, verification, and implement control. The composition analysis for data collection and data analysis was used in the cellular phone module packaging lines. And this method was evaluated by the variation of yield loss between before and after improvement action. In case that the composition analysis was applied, the critical sources were selected and yield loss reduction through improvement actions was also investigated. From these results, it is concluded that the composition analysis is effective solutions for particle contamination control in the cleanroom.

• 한국대기환경학회지
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• 제12권4호
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• pp.377-387
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• 1996

This study was carried out to monitor the visibility including measurement and analysis of the various parameters such as particle size distribution, chemical composition, and meteorotical conditions to understand the characteristics and causes of this phenomenon. According to the analysis of intensive sampling, $SO_4^{2-}, NO-3^-, Cl^-, NH_4^+$ ion concentration increased together with the mass concentration around 1 $\mu$m in the case of low visibility. $(NH_4)_2SO_4, NH_4NO_3$, and $NH_4Cl$ were thought to be the major components of fine particles. The statistical analysis showed that the scattering effect of particle was 81.2%, the absorption effect was 14.9%. Therefore, these effects were the major factors to reduce the visibility. In conclusion, the visibility was reduced by the fine particle of sulfate (18.6%), nitrate (14.2%), organic carbon (10.8%), element carbon (25.8%), and residual (24.8%) during this study.

• 대한기계학회논문집B
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• 제31권6호
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• pp.522-530
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• 2007

The practical studies on the method of particle contamination control for yield enhancement in the cleanroom were carried out. The method of the contamination control was proposed, which are composed of data collection, data analysis, improvement action, verification, and implement control. The partition check method and the composition analysis for data collection and data analysis were respectively used in the main board and the cellular phone module production lines. And these methods were evaluated by the variation of yield loss between before and after improvement action. In case that the partition check method was applied, the critical process step was selected and yield loss reduction through improvement actions was observed. While in case that the composition analysis was applied, the critical sources were selected and yield loss reduction through improvement actions was also investigated. From these results, it is concluded that the partition check and the composition analysis are effective solutions for particle contamination control in the cleanroom production lines.

• 광물과 암석
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• 제36권4호
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• pp.345-353
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• 2023

본 연구는 상업용 영동 일라이트 분말 제품의 판매 규격, 즉 메쉬(mesh)에 따른 구성광물, 입도, 화학조성의 차이를 조사하여, 일라이트 분말 제품의 특성을 이해하고 다양한 활용 분야를 개척하기 위한 광물학적 데이터베이스로 활용하고자 하였다. 충청북도 영동군의 광산을 보유한 두 곳의 회사에서 제공받은 상업용 일라이트 분말 시료를 X-선 회절 분석, 레이저 회절 입도 분석, 주사전자현미경 분석, X-선 형광 분석을 이용해 조사하였다. X-선 회절 분석 결과, 두 광산의 일라이트 분말 제품에는 주로 일라이트 및 백운모, 석영, 사장석이 존재하며, 이는 각 광산의 광석의 구성광물과 일치하는 경향을 보인다. 레이저 회절 입도 분석에서는 제품 규격에 따라 입자 크기의 차이가 나타났으며, 입도의 균일성은 메쉬가 높아질수록 증가하는 경향을 보였다. 주사전자현미경 분석에서는 입자의 형태와 크기가 규격에 따라 다르게 나타났다. 일라이트 입자의 크기는 제품의 규격 메쉬에 따른 차이가 크게 없으며, 주로 장석 및 석영의 입자 크기에 변화가 발생하는 것으로 나타났다. 또한, 시료의 화학 조성은 광산마다 다소의 차이가 있으나, 규격별로 큰 차이는 나타나지 않았다. 이러한 결과를 토대로, 상업용 일라이트 분말의 활용 분야를 고려할 때 규격에 따른 특성 변화를 고려하여 선택하는 것이 중요하다. 본 연구 결과는 상업용 일라이트 분말의 다양한 응용 가능성을 제시하며, 산업적 활용 및 새로운 기술 개발에 기여할 것으로 기대된다.

• 한국대기환경학회지
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• 제15권2호
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• pp.175-182
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• 1999

Scanning electron microscopy (SEM) has played an important role in receptor modeling area because it is a powerful tool for characterizing individual particles. The purpose of the study was to classify individual diesel particles base on statistical analysis and image analysis by SEM/EDX (energy dispersive x-ray analyser). The diesel particles were sampled by both a modified CVS 75 mode and a high speed mode with a chassis dynamometer. The SEM/EDX system provides various physical parameters including particle's particle diameter and chemical information. Thus density and mass of the diesel particle were estimated cased on its chemical composition and further fractal dimensions of the diesel particle were obtained by the Hurst exponent method. The fractal dimension in the sample of modified CVS 75 mode was higher than the high speed mode. Finally, mass fractions for a diesel vehicle as a source profile were estimated cased on a particle class concept.

• 한국전기전자재료학회논문지
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• 제17권7호
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• pp.747-753
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• 2004

In this paper, nanocrystalline indium tin oxide (ITO) particles were fabricated by using synthesis without harmful elements. The synthetic method is to eliminate the chloridic and nitridic elements which are included in the current wet type synthetic method. Therefore, it is possible to lower synthetic temperature below 600 $^{\circ}C$ to eliminate the harmful elements. Accordingly, fine particle can be achieved by applying the process. Particle size, surface area, crystal structure, and composition ratio of the synthesized nanocrystalline ITO particle by using the method were analyzed with high resolution transmission electron microscopy (HRTEM), BET surface area analyzer, X-ray diffraction (XRD), and energy dispersion spectroscopy (EDS). As a result, its particle size is less than 10 nm, and the surface area exceeds 100 m$^2$/g. The XRD analysis indicates that the cystal structure of the powder is cubic one with orientation of <222>, <400>, <440>. Also, the analysis of the composition demonstrates that the around 8 wt% tin is uniformly included in In$_2$O$_3$ lattice of the nanoparticle.

• 한국세라믹학회지
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• 제26권6호
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• pp.737-746
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• 1989

After Ba-ferrite powders synthesized hydrothermally and its heated powders were dissolved partially with HCl treatment time, the BaO/Fe2O3 mole ratio of dissolved solutions and powders were measured by AAS, also, lattice constants, particle morphology and magnetic properties in HCl treated, heated and no-heated Ba-ferrite powders were abtained by means of XRD, SEM and VSM, respectively. From above analysis results, the effect of Ba/Fe mole ration in suspension(as starting material) on the BaO/Fe2O3 composition and particle characteristics of products were investigated, and the effect of heat treatment on magnetic properties of products examined. The composition, lattice constant and crystal phase of products depend on the Ba/Fe mole ratio in suspension. Ba content in surface or outer part of Ba-ferrite powder is higher than inner and heterogeneous, and the excess Ba ions in the inner part of particle move into the outer by heating, so that the mole ratio of BaO/Fe2O3 in the more jinner approaches more to the stoichiometric composition 1 : 6. The crystallinity, coercivity and saturation magnetization of products are increased by heat treatment, and the heat-treated samples synthesized hydrothermally in lower temperature are appreciated to have better powder characteristics.

• 한국환경과학회지
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• 제22권1호
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• pp.7-15
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• 2013

Aerosol characterization study for individual particle in Busan metropolitan industrial complex was carried out from December 2010 to August 2011. SEM(scanning electron microscope)-EDX(energy dispersive x-ray) analysis was used for the analysis of 600 single particles during the sampling periods to identify non-metallic aerosol particle sources. Average $PM_{10}$ concentration was 65.5 ${\mu}g/m^3$ in summer, 104.1 ${\mu}g/m^3$ in winter during the sample periods. And Average $PM_{2.5}$ concentration was 24.5 ${\mu}g/m^3$ in summer, 64.5 ${\mu}g/m^3$ in winter individually. Particle density, enrichment factor, correlation analysis, principle component analysis were performed based on chemical composition data. Particle density distribution was measured to 2~4 $g/cm^3$, and the density of $PM_{2.5}$ was measured above 3 $g/cm^3$. In general, the elements Si, Ca, Fe and Al concentrations were higher in all samples of individual particles. The non-ferrous elements Zn, Br, Pb, Cu concentrations were higher in summer than in winter. The concentrations were not changed with the seasons because of non-ferrous industry emission pattern.

• Asian Journal of Atmospheric Environment
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• 제4권3호
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• pp.115-140
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• 2010

Great concerns about atmospheric aerosols are attributed to their multiple roles to atmospheric processes. For example, atmospheric aerosols influence global climate, directly by scattering or absorbing solar radiations and indirectly by serving as cloud condensation nuclei. They also have a significant impact on human health and visibility. Many of these effects depend on the size and composition of atmospheric aerosols, and thus detailed information on the physicochemical properties and the distribution of airborne particles is critical to accurately predict their impact on the Earth's climate as well as human health. A single particle analysis technique, named low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA) that can determine the concentration of low-Z elements such as carbon, nitrogen and oxygen in a microscopic volume has been developed. The capability of quantitative analysis of low-Z elements in individual particle allows the characterization of especially important atmospheric particles such as sulfates, nitrates, ammonium, and carbonaceous particles. Furthermore, the diversity and the complicated heterogeneity of atmospheric particles in chemical compositions can be investigated in detail. In this review, the development and methodology of low-Z particle EPMA for the analysis of atmospheric aerosols are introduced. Also, its typical applications for the characterization of various atmospheric particles, i.e., on the chemical compositions, morphologies, the size segregated distributions, and the origins of Asian dust, urban aerosols, indoor aerosols in underground subway station, and Arctic aerosols, are illustrated.

• 한국대기환경학회지
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• 제13권5호
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• pp.345-353
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• 1997

The purpose of the study was to stastically classify individual PM-10 measured by SEM/EDX (scanning electron microscopy/energy dispersive x-ray analyzer). The SEM/EDX provided various physical parameters like optical diameter, as well as major 18 chemical information (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Pb) for a particle-by-particle basis. The total of 1,419 particles were analyzed for the study. Thus density and mass of each particle can be estimated based on its chemical composition. Further the study developed 4 semisource profiles including highway, oil boiler, incinerator, and soil emissions, where each sample was collected near the source in the ambient air The profiles developed were consisted of mass fractions and their uncertainties based on a particle class concept. To obtain mass fraction of each particle class, an agglomerative hierarchical cluster analysis was initially applied to create particle classes for each sample. Then uncertainties were calculated for each class based on the jacknife method. The 1,258 particles out of 1,419 (88.7%) were assorted in newly generated particle classes. The study provides opportunities to identify particle's source quantitatively and to develope various receptor models.