• 한국의류학회지
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• 제39권2호
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• pp.287-293
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• 2015

This research verifies stainability, super bacteria antibacterial features and antibiotic resistance of Ulmus davidiana var. japonica Nakai (UD) extract in dye cotton cloth. UD was extracted with hot water, the test cloth dyed, and then processed by mordanting treatment using $FeSO_4$ $7H_2O$, $CuSO_4$ $5H_2O$ and $Al_2(SO_4)_3$. The surface color and color fastness of the three kinds (original cloth, the cloth without mordancy and mordant cloth) were measured and the influence of dying of cotton cloth and the mordant method on the genesistasis of Methicillin-resistant Staphylococcus aureus (MRSA), antibiotic resistant bacteria. 1. The surface color of the cotton cloth for dyeing (without and with mordancy) displayed a reddish and yellowish color. Stainability was greatest when the mordant of $FeSO_4$ $7H_2O$ was used. 2. When a mordant was not used for dyeing, the color fastness to washing, perspiration and friction of the contaminated cloth was satisfactory at 4 to 5 grade in general. 3. As for the antibiotic effect to super bacteria, the growth of germ was meaningfully suppressed both on the cloth without and with mordancy compared to the comparison cloth; in addition, the dyeing method with the biggest antibacterial impact was found to be the mordancy with the mordant of $CuSO_4$ $5H_2O$ after dyeing. The results of the experiments that involved dyeing with UD extract showed that cotton cloth processed through mordancy with the mordant of $CuSO_4$ $5H_2O$ had the biggest antibiosis to super bacteria and that processed with the mordant of $FeSO_4$ $7H_2O$ had the greatest stainability.

• 한국환경농학회지
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• 제11권3호
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• pp.195-200
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• 1992

매장량(埋藏量)이 풍부한 peat를 중금속(重金屬) 흡착제(吸着劑)로서의 이용(利用) 가능성(可能性)을 확인(確認)하기 위한 실험(實驗)을 행한 결과(結果) 다음과 같았다. Peat의 입자(粒子)가 적을수록 중금속(重金屬) 흡착(吸着)이 효과적(效果的)이었으며 동일(同一) 농도용액(濃度溶液)에서 중금속(重金屬) 흡착량(吸着量)은 $Cu^{2+}$ > $Cd^{2+}$ > $Zn^{2+}$순(順) 이었다. Peat는 pH $4{\sim}5$사이에서 중금속(重金屬)의 최대흡착(最大吸着)이 일어났다. 중금속(重金屬) 농도(濃度)가 증가(增加)할수록 중금속(重金屬)의 흡착량(吸着量)의 증가(增加)되었으나 흡착율(吸着率)은 감소(減少)되었다. Peat에 의한 중금속(重金屬) 이온흡착은 Freundlich 흡착등온식(吸着等溫式)에 잘 적용(適用)되므로 효과적(效果的)인 흡착제(吸着劑)로 생각되며 peat에 PEI(polyethylenimine)를 처리(處理)하면 중금속(重金屬)의 흡착량(吸着量)이 증가(增加)하여 효과적(效果的)이었다. 중금속(重金屬) 흡착후(吸着後) peat의 처리방법(處理方法)은 열량(熱量)이 풍부하여 연료원(燃料源)으로 사용후(使用後) 용량(容量)을 줄일 수 있어서 경제적(經濟的)인 처리방법(處理方法)으로 생각된다.

• 한국표면공학회지
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• 제36권5호
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• pp.373-378
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• 2003

With increasing environmental concerns, application of lead-free solder and fluxless soldering process have been taken attention from the electronic packaging industry. Plasma treatment is one of the soldering methods for the fluxless soldering, and it can prevent environmental pollution cased by flux. On this study fluxless soldering process under $Ar-H_2$plasma using lead free solders such as Sn-3.5 wt%Ag, Sn-3.5 wt%Ag-0.7 wt%Cu and Sn-37%Pb for a reference was investigated. As the plasma reflow has higher soldering temperature than normal air reflow, the effects of UBM(Under Bump Metallization) thickness on the interfacial reaction and bonding strength can be critical. Experimental results showed in case of the thin UBM, Au(20 nm)/Cu(0.3 $\mu\textrm{m}$)/Ni(0.4 $\mu\textrm{m}$)/Al(0.4 $\mu\textrm{m}$), shear strength of the soldered joint was relatively low as 19-27㎫, and it's caused by the crack observed along the bonded interface. The crack was believed to be produced by the exhaustion of the thin UBM-layer due to the excessive reaction with solder under plasma. However, in case of thick UBM, Au(20 nm)/Cu(4 $\mu\textrm{m}$)/Ni(4 $\mu\textrm{m}$)/Al(0.4 $\mu\textrm{m}$), the bonded interface was sound without any crack and shear strength gives 32∼42㎫. Thus, by increasing UBM thickness in this study the shear strength can be improved to 50∼70%. Fluxed reflow soldering under hot air was also carried out for a reference, and the shear strength was 48∼52㎫. Consequently the fluxless soldering with plasma showed around 65∼80% as those of fluxed air reflow, and the possibility of the $Ar-H_2$ plasma reflow was evaluated.

• 한국물환경학회지
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• 제38권2호
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• pp.82-94
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• 2022

In this study, chemically modified biochar (NSBP500, KSBP500, OSBP500) derived from starfish was utilized to improve the adsorption ability of the SBP500 (Starfish Biochar Pyrolyzed at 500℃) in a solution contaminated with heavy metals. According to the biochar modification performance evaluation batch tests, the removal rate and adsorption amount of NSBP500 increased 1.4 times for Cu, 1.5 times for Cd, and 1.2 times for Zn as compared to the control sample SBP500. In addition, the removal rate and adsorption amount of KSBP500 increased 2 times for Cu, 1.8 times for Cd, and 1.2 times for Zn. The removal rate and adsorption amount of OSBP500 increased 5.8 times for Cu. The FT-IR analysis confirmed the changes in the generation and movement of new functional groups after adsorption. SEM analysis confirmed Cu in KSBP500 was in the form of Cu(OH)₂ and resembled the structure of nanowires. The Cd in KSBP500 was densely covered in cubic form of Cd(OH)₂. Lead(Pb) was in the form of Pb₃(OH)₂(CO₃)₂ in a hexagonal atomic layer structure in NSBP500. In addition, it was observed that Zn was randomly covered with Zn₅(CO₃)₂(OH)₆ pieces which resembled plates in KSBP500. Therefore, this study confirmed that biochar removal efficiency was improved through a chemical modification treatment. Accordingly, adsorption and precipitation were found to be the complex mechanisms behind the improved removal efficiency in the biochar. This was accomplished by electrostatic interactions between the biochar and heavy metals and ion exchange with Ca²⁺.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년 추계학술발표대회 개요집
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• pp.136-138
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• 2006

Recently a lots of problems have observed in high densified and high integrated electronic components. One of them is ion migration phenomena, which induce the electrical short of electrical circuit. Ion migration phenomena has been observed in the field of exposing the specific environment and using for a long time. Also as the RoHS restriction was started in July 1st, 2006, Pb-free solder was utilized in electronics assemblies. In this case, it is very important to compatible between components and printed circuit board(PCB), thus surface treatment materials of PCB was changed to Sn, Sn-3.0Ag-0.5Cu, Cu. Therefore these new application become to need to reevaluate the sensitivity about electrochemical ion migration. This study was evaluated the occurrence time of electrochemical ion migration using by water drop test. We utilized PCB(printed circuit board) having a comb pattern as follows 0.1, 0.318, 0.5, 1.0 mm pattern distance. Sn-3.0Ag-0.5Cu and Sn-37Pb were electroplated on the comb pattern. 6.5V and 15.0V were applied in the comb pattern and then we measured the electrical short time causing by occurring the ion migration. In these results, we evaluate the sensitivity and derived the prediction models of ion migration occurrence time depending on the pattern materials, applied voltage and pattern spacing of PCB conductor.

• 대한금속재료학회지
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• 제48권12호
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• pp.1130-1135
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• 2010

Cu/carbon nano-particle hybrids were fabricated through the cathodic electrophoretic deposition (EPD) process. CNT and CNF nano-particles were modified to give positive charges by polyethyleneimine (PEI) treatment before depositing them on the substrate. Since a Cu plate was used as an anode in the EPD process, Cu particles were also deposited along with the carbon nano-particles. Experimental observation showed the nano-hybrids constructed a novel formicary-like nano-structure which is strong and highly conductive. Utilizing the hybrids, carbon fiber composites were manufactured, and their electrical conductivity and interlaminar shear strength were measured. In addition, the deposition morphology and failure surface were examined by SEM observations. Results demonstrated that the electrical conductivities in the through-the-thickness direction and the interlaminar shear strength significantly increased by 350~2100% and 14%, respectively.

• 마이크로전자및패키징학회지
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• 제30권4호
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• pp.8-16
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• 2023

디바이스 소형화의 한계에 다다르면서, 이를 극복할 수 있는 방안으로 차세대 패키징 기술의 중요성이 부각되고 있다. 병목 현상을 해결하기 위해 2.5D 및 3D 인터커넥트 피치의 필요성이 커지고 있는데, 이는 신호 지연을 최소화 할 수 있도록 크기가 작고, 전력 소모가 적으며, 많은 I/O를 가져야 하는 등의 요구 사항을 충족해야 한다. 기존 솔더 범프의 경우 미세화 한계와 고온 공정에서 녹는 등의 신뢰성 문제가 있어, 하이브리드 본딩 기술이 대안책으로 주목받고 있으며 최근 Cu/SiO₂ 구조의 문제점을 개선하고자 SiCN에 대한 연구 또한 활발히 진행되고 있다. 해당 논문에서는 Cu/SiO₂ 구조 대비 Cu/SiCN이 가지는 이점을 전구체, 증착 온도 및 기판 온도, 증착 방식, 그리고 사용 가스 등 다양한 증착 조건에 따른 SiCN 필름의 특성 변화 관점에서 소개한다. 또한, SiCN-SiCN 본딩의 핵심 메커니즘인 Dangling bond와 OH 그룹의 작용, 그리고 플라즈마 표면 처리 효과에 대해 설명함으로써 SiO₂와의 차이점에 대해 기술한다. 이를 통해, 궁극적으로 Cu/SiCN 하이브리드 본딩 구조 적용 시 얻을 수 있는 이점에 대해 제시하고자 한다.

• 공업화학
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• 제32권6호
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• pp.671-678
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• 2021

암모니아의 흡착 성능을 향상할 목적으로 활성탄의 질산 처리 및 활성탄으로 금속 염화물의 첨착 효과를 연구하였다. 질산 처리에 의해 활성탄으로 하이드록시기 및 카르복실기와 같은 작용기들의 도입을 확인하였다. 이후 초음파 함침법을 사용하여 각 금속 염화물(NiCl₂, MgCl₂, CuCl₂, MnCl₂ 또는 CoCl₂)을 표면 개질 활성탄 위로 첨착하였다. 여러첨착된 활성탄들의 물리화학적 특성과 암모니아 흡착 성능을 관찰하였다. 금속 염화물은 초음파 처리에 의해 원활하게 분산되었으며 활성탄 표면 위에 고르게 분포되었다. 금속 염화물이 첨착된 표면 개질 활성탄은 감소된 비표면적 및 세공 부피에도 불구하고 매우 우수한 암모니아 흡착 성능을 나타내었다. 특히, NiCl₂를 첨착하여 제조한 HNO₃-NiCl₂ AC는 가장 우수한 암모니아 흡착능(3.736 mmol·g^-1)을 나타내었으며, 미처리된 활성탄(0.066 mmol·g^-1)과 비교하여 약 57배 향상되었다.

• 열처리공학회지
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• 제23권1호
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• pp.23-28
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• 2010

The cylindrical magnetron sputtering has not been widely used, although this system is useful for only certain types of applications such as fiber coatings. This paper presents electrode configurations which improved the complicacy of the target assembly by using the positive voltage power supply. It is a modified type which has a target constructed with a large cylindrical part, a conical part and a small cylindrical part. When positive voltage was applied to an anode, a stable glow discharge was established and a high deposition rate was obtained. The substrate bias current was monitored to estimate the effect of ion bombardment. As a result, it was found that the substrate current was large. With cylindrical and conical cathode magnetron sputter deposition on the surface of the substrate to prevent re-sputtering, ion impact because it can increase the effectiveness with excellent ductility and adhesion of Ti film deposition can be obtained. We board at the front end of the ground resistance of $5\;k{\Omega}$ attached to the substrate potential can be controlled easily, and Ti film deposition with excellent adhesion can be obtained. Microstructure and morphology of Ti films deposited on pure Cu wires were investigated by scanning electron microscopy in relation to preparation conditions. High level ion bombardment was found to be effective in obtaining a good adhesion for Cu wire coatings.

• 멤브레인
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• 제34권1호
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• pp.50-57
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• 2024

본 실험에서는 α-Al₂O₃ 지지체에 무전해도금을 이용하여 Pd-Ag-Cu 분리막을 제조하였다. Pd, Ag, Cu는 각각 무전해도금을 통해 지지체 표면에 코팅하였고, 합금의 형성을 위해 무전해도금 중간에 H₂, 500℃의 조건에서 18 h 동안 열처리를 진행하였다. 이를 통해 제조된 Pd-Ag-Cu 분리막은 SEM을 통해 표면을 관찰하였으며, Pd 분리막의 두께는 7.82 ㎛, Pd-Ag-Cu 분리막의 두께는 3.54 ㎛로 측정되었다. EDS와 XRD 분석을 통해 Pd-Ag-Cu 합금이 Pd-78%, Ag-8.81%, Cu-13.19%의 조성으로 형성된 것을 확인하였다. 기체투과 실험은 H₂ 단일가스와 H₂/N₂ 혼합가스에서 실험을 진행하였다. H₂ 단일가스에서 측정한 수소 분리막의 최대 H₂ flux는 Pd 분리막의 경우 450℃, 4 bar에서 74.16 ml/cm²·min이고, Pd-Ag-Cu 분리막의 경우 450℃, 4 bar에서 113.64 ml/cm²·min인 것을 확인하였고, H₂/N₂ 혼합가스에서 측정한 separation factor의 경우 450℃, 4 bar에서 각각 2437, 11032의 separation factor가 측정되었다.