• Proceedings of the KWS Conference
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• 2010.05a
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• pp.80-80
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• 2010

전자제품의 소형화, 경량화, 고집적화가 심화됨에 따라 전자제품을 구성하는 회로의 미세화 또한 요구되고 있다. 이러한 요구는 경성회로기판 (rigid printed circuit board, RPCB) 뿐만 아니라 연성회로기판 (flexible printed circuit board, FPCB) 에도 적용되고 있으며 이에 대한 많은 연구 또한 이루어지고 있다. 연성회로기판은 일반적으로 절연층을 이루는 폴리이미드 (polyimide, PI)와 전도층을 이루는 구리로 이루어져 있다. 폴리이미드는 뛰어난 열적 화학적 안정성, 우수한 기계적 특성, 연속공정이 가능한 장점을 가지고 있으나, 고온다습한 환경하에서 높은 흡습성으로 인해 전도층을 이루는 구리와의 접합특성이 저하되는 단점 또한 가지고 있다. 또한 전도층을 이루는 구리는 고온다습한 환경하에서 산화 발생이 용이하기 때문에 접합특성의 감소를 야기할 수 있다. 따라서 본 연구에서는 고온다습한 조건하에서 sputtering and plating 공정을 통해 순수 Cr seed layer를 가지는 연성회로기판의 seed layer의 두께와 시효시간의 변화로 인해 발생하는 접합특성의 변화를 관찰하고 분석하였다. 본 연구에서는 두께 $25{\mu}m$의 일본 Kadena사(社)에서 제작된 폴리이미드 상에 sputtering 공정을 통해 순수 Cr으로 이루어진 각각 두께 100, 200, $300{\AA}$의 seed layer를 형성한 후 전해도금법을 이용, 두께 $8{\mu}m$의 구리 전도층을 형성한 시료를 사용하였다. 제작된 시료는 고온다습한 환경하에서의 접합 특성의 변화를 관찰하기 위하여 $85^{\circ}C$/85%RH 항온항습 조건하에서 각각 24, 72, 120, 168시간 동안 시효처리 한 후, Interconnections Packaging Circuitry (IPC) 규격에 의거하여 접합강도를 측정하였다. 시료의 전도층은 폭 3.2mm 길이 230mm의 패턴을 가지도록, 절연층은 폭 10mm, 길이 230mm으로 구성되었으며 이를 50.8mm/min의 박리 속도로 각 시편당 8회의 $90^{\circ}$ peel test를 실시하였다. 파면의 형상과 화학적 조성을 분석하기 위해 SEM (Scanning electron microscope)과 EDS (Energy-dispersive X-ray spectroscopy)를 사용하였으며, 파면의 조도 측정을 위해 AFM (Atomic force microscope)을 사용하였다. 또한 계면의 화학적 결합상태를 분석하기 위해 XPS (X-ray photoelectron spectroscopy)를 통해 파면을 관찰 분석하였다.

• Journal of the Mineralogical Society of Korea
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• v.29 no.3
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• pp.103-111
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• 2016

Li-bearing hectorite, one member of trioctahedral smectite, occurred large in quantity and confirmed in Turkey western sedimentary boron deposit. Li-bearing hectorite attracted a particular attention because it is one of potential lithium resources. There have been no consensus for the change of hectorite due to heat and acid treatment although it is very important to use in industrial application. In this study, we examined changes of hectorite after heat and acid treatment as well as acid treatement followed by heating. We used clay ores collected in Bigadic deposit, which contained the highest $Li_2O$ content in Turkey boron deposits. Hectorite showed a strong endothermic reaction at $84^{\circ}C$ due to dehydration of absorbed water and interlayer water and a weak endothermic reaction above $600^{\circ}C$ owing to dehydration of crystallization water. The first endothermic reaction accompanied a large weight loss about 6%. Hectorite decomposed into enstatite, cristobalite and amorphous Fe material at $762^{\circ}C$ with exothermic reaction. When hectorite reacted with 3 kinds of 0.1 M acid during 1 hours, it had a good dissolution efficiency with $H_2SO_4{\geq}HCl$ > $HNO_3$ in order.

• Economic and Environmental Geology
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• v.38 no.3 s.172
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• pp.335-346
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• 2005

In this study, core sediments and pore water were analysed to identify the origin of organic matter and Bas in late Quaternary sediments from the northwestern Ulleung Basin of the East Sea. C/N and C/S ratios in the sediments show that the organic matter in the study area originated predominantly from marine algae. However, the results of Rock-Eval pyrolysis indicate that the organic matter has an origin of the land-plant (Type III), locating in the immature stage. These different results might be due to the heavy oxidizing of the organic matter during sinking down to the seafloor or after deposition in the sediments. Concentration of sulfate in the pore water decreases gradually with core depth, while concentration of $CH_4$ increases gradually with core depth. This indicates that sulfate reduction and methanogenesis occurred actively in the sediments. Also, it is likely that the compositions of $CH_4$ are characterized as a more biogenic origin, mostly caused by microbial activity, rather than a thermogenic one.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.75-75
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• 2009

연성회로기판은 일반적으로 절연체를 이루는 폴리이미드와 전도체를 이루는 구리로 구성되어 있다. 폴리이미드는 뛰어난 열적 화학적 안정성, 기계적 특성, 공정성 등의 장점으로 인해 연성회로기판의 절연체로서 제안되었지만 전도체를 이루는 구리와의 접합 특성이 우수하지 않기 때문에 많은 연구가 현재까지 진행되고 있고, 그 결과 연성회로기판의 접합 특성에 많은 개선이 이루어짐과 동시에 다양한 공정 방법이 제안되고 있다. 하지만 고온다습한 환경에서 사용될 경우 폴리이미드의 높은 흡습성과, 구리와 seed layer의 산화 문제로 인해 접합 특성이 저하된다는 단점 또한 가지고 있다. 따라서 본 연구를 통해 고온다습한 조건하에서 seed layer가 80Ni/20Cr 합금으로 구성된 연성회로기판의 seed layer의 두께와 시효시간으로 인해 발생하는 접합 신뢰성의 차이를 관찰하였다. 본 연구에서는 두께 $25{\mu}m$의 폴리이미드 위에 각각 100, 200, $300{\AA}$ 두께의 80Ni/20Cr의 합금 조성을 가지는 seed layer를 스퍼터링 공정을 통해 형성한 후 전해도금법을 이용하여 $8{\mu}m$ 두께의 구리 전도층을 형성하였다. 접합 특성 평가를 위해 ICP 규격에 따라 전도층 패턴을 폭 3.2mm, 길이 230mm로 시편을 제작하여 50.8mm/min의 이송 속도로 각 시편당 8회의 $90^{\circ}$ peel test를 실시하였다. 또한 $85^{\circ}C$/85% 항온항습 조건하에서 각각 24, 72, 120, 168시간 동안 시효 처리 후 같은 방법으로 연성회로기판의 접합 특성을 평가하였다. 파면의 형상과 조성을 분석하기 위해 SEM (Scanning electron microscope)과 EDS (Energy-dispersive X-ray spectroscopy)를 사용하였으며, 파면의 조도 측정을 위해 AFM (Atomic force microscope)을 사용하였다. 또한 파면의 잔여물 분석을 위해 EPMA (Energy probe microanalysis)를 사용하였고 계면의 화학적 결합상태를 분석하기 위해 XPS (X-ray photoelectron spectroscopy)를 통해 파면을 분석하였다.

• Korean Journal of Materials Research
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• v.2 no.2
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• pp.126-132
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• 1992

Experiment has been performed to investigate the thermal and magnetic properties of Mn-ferrite by electrolysis. Using the 0.2%C mild steel as soluble anode and SUS 304 stainless steel as cathode, Mn-ferrite could be made from the sulfuric acid leaching of the wasted manganese dry cell and $MnSO_4$reagent by electrolysis. As the result of X-ray diffraction, thermal analysis and magnetic measurement, Mn-ferrite was the spinel type in $Mn_{x}Fe_{3-x}O_4$ (X=1), the weight loss rate of $Mn_{x}Fe_{3-x}O_4$ were linearly increased up to the $200^{\circ}C$. Ms, Mr and Hc values were decreased with increasing Mn content and heating temperature. When Mn-ferrite was formed by $MnCl_2$reagent electrolysis, Ms values were higher than those formed from the sulfuric acid leaching of the wasted manganese dry cell and $MnSO_4$reagent by electrolysis. In Mn-ferrite, which was formed from the sulfuric acid leaching of the wasted manganese dry cell by electrolysis, Ms and Mr values were higher, Hc values were lower than which was formed by $MnSO_4$ reagent electrolysis at $200^{\circ}C\;and\;300^{\circ}C, while the same values at $100^{\circ}C$. The shape of particles was spherical type, the sizes of them were about $0.1{\mu}m$ sub-micron in $MnSO_4$reagent electrolysis, $0.5{\mu}m$ in the sulfuric acid leaching of the wasted manganese dry cell by electrolysis.

• Membrane Journal
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• v.20 no.4
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• pp.312-319
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• 2010

Carbon membrane materials have received considerable attention for the gas separation including hydrocarbon mixture of ingredients of the volatile organic compounds(VOCs) because they possess their higher selectivity, permeability, and thermal stability than the polymeric membranes. The use of activated carbon membranes makes it possible to separate continuously the VOCs mixture by the selective adsorption-diffusion mechanism which the condensable components are preferentially adsorbed in to the micropores of the membrane. The activated carbon hollow fiber membranes with uniform adsorptive micropores on the wall of open pores and the surface of the membranes have been fabricated by the carbonization of a thin film of phenolic resin deposited on porous alumina hollow fiber membrane. Oxidation, carbonization, and activation processing variables were controlled under different conditions in order to improve the separation characteristics of the activated carbon membrane. Properties of activated carbon hollow fiber membranes and the characterization of a gas permeation by pyrolysis conditions were studied. As the result, the activated carbon hollow fiber membranes with good separation capabilities by the molecular size mechanism as well as selective adsorption on the pores surface followed by surface diffusion effective in the recovery hydrocarbons have been obtained. Therefore, these activated carbon membranes prepared in this study are shown as promising candidate membrane for separation of VOCs.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.1
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• pp.47-53
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• 2012

Bonding strength of Sn-3.0Ag-0.5Cu solder joint due to degradation characteristic of OSP surface finish was investigated, compared with SnPb finish. The thickness variation and degradation mechanism of organic solderability preservative(OSP) coating were also analyzed with the number of reflow process. To analyze the degradation degree of solder joint strength, FR-4 PCB coated with OSP and SnPb were experienced preheat treatment as a function of reflow number from 1st to 6th pass, respectively. After 2012 chip resistors were soldered with Sn-3.0Ag-0.5Cu on the pre-heated PCB, the shear strength of solder joints was measured. The thickness of OSP increased with increase of the number of reflow pass by thermal degradation during the reflow process. It was also observed that the preservation effect of OSP decreased due to OSP degradation which led Cu pad oxidation. The mean shear strength of solder joints formed on the Cu pads finished with OSP and SnPb were 58.1 N and 62.2 N, respectively, through the pre-heating of 6 times. Although OSP was degraded with reflow process, the feasibility of its application was proven.

• Journal of the Korean Chemical Society
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• v.40 no.5
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• pp.295-301
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• 1996

A series of solid solutions of the $CaGa_1-xFexO_3-y$ system with the compositions of x=0.25, 0.50, 0.75, and 1.00 has been prepared at $1150^{\circ}C$ under an atmospheric air pressure. The structure, nonstoichiometric chemical formula, and the distribution of cations for the solid solutions are determined by X-ray diffraction analysis, Mohr salt titration, Mossbauer spectroscopic analysis. Their physical properties are discussed with electrical conductivity and magnetic measurements. The crystal system of all the compositions is a brownmillerite orthorhombic system from the X-ray diffraction analysis and the reduced lattice volume increases linearly with x value except that of the composition of x=0.25. All the solid solutions do not contain $Fe^{4+}$ ion and the mole number of oxygen vacancies or y value is 0.50 from Mohr salt analysis. The oxidation state of Fe ion, the coordination state, the structure change in the Brownmillerite-type structure, and the distribution of $Ga^{3+}$ and $Fe^{3+}$ ions are discussed with Mossbauer spectroscopic analysis. The electrical conductivity increases and activation energy decreases, as x value increases. The traditional semiconducting property of this system is described in terms of band theory. The compositions of x=0.50∼1.00 show a thermal magnetic hysteresis in the magnetic measurement with the cooling conditions, which is discussed in terms of the space group and Dzyaloshinsky-Moriya interaction.

• Elastomers and Composites
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• v.14 no.3
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• pp.161-168
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• 1979

이 논문(論文)의 목적(目的)은 열적안정성(熱的安定性) 및 내노화성면(耐老化性面)에 있어서 디엔제3성분단위체(第三成分單位體)(diene termonomer)의 각각(各各)의 종류(種類)가 EPDM의 중합체(重合體)의 성질(性質)에 미치는 효과(效果)를 구명(究明)하는데 있다. 제3성분단위체(第三成分單位體) 5종(種)으로 각각(各各) 다음과 같다. 즉, ethylidene norbonene(ENB), butadiene(BD), dicyclopentadiene(DCPD), methyltetrahydroindene (MTHI) 및 1,4-hexadiene(HD)이다. 이들을 써서 만든 각각(各各)의 EPDM은 동(同)몰의 불포화도(不飽和度)로 만들어졌다. 또한 가황계(加黃系)는 동일(同一)한 황/촉진제계(黃/促進劑系)를 사용(使用)하였다. ENB-EPDM이 순(純)고무배합체(配合體) 및 충전제함유배합체(充塡劑含有配合體)의 가황(加黃)에 있어서 모두 함께 가장 빠른 가황속도(加黃速度)를 보였다. HD-EPDM은 순(純)고무배합체(配合體)에서 가황속도(加黃速度)가 가장느렸으나 충전제함유배합물(充塡劑含有配合物)에서는 DCPD-EPDM보다는 발랐다. BD-EPDM을 제외(除外)한 이들 중합체(重合禮)는 거의 같은 초기가교밀도(初期架橋密度)를 갖는다. 가교밀도(架橋密度) 및 가교형(架橋型)을 분석(分析)하여 보면 BD-EPDM 쇄(鎖)에서 부타디엔 단위(單位)는 블럭을 이루고 있다. 또한 HD-EPDM은 순(純)고무가황체(加黃體) 및 충전제배합가황체(充塡劑配合加黃體)에 있어서 원가교결합(原架橋結合)의 50%가 monosulfide의 구조(構造)를 가지고있다. 이외(外)의 4종(四種)의 EPDM 폴리머는 보다 낮은 monosulfide구조를 가진다. $177^{\circ}C(350^{\circ}F)$의 노화온도(老化溫度)에서 ENB 및 HD폴리머는 약(約) 65% monosulfide 가교(架橋) 및 거의 동일(同一)한 파괴에너지값$(E_b)$을 가진다. 그러나 1,4HD의 원가교(原架橋)의 monosulfide 구조함량(含量)이 보다 높다고 해서 그의 내노화성(耐老化性)이 다른 폴리머보다 더 좋다고는 생각되지 않는다. DCPD는 $177^{\circ}C(350^{\circ}F)$의 노화온도(老化溫度)에서 똑같은 monosulfide가교(架橋)를 가지나 노화온도(老化溫度)가 $259^{\circ}C(500^{\circ}F)$로 높아짐에 따라 monosulfide 함량(含量)도 증가(增加)한다. $550^{\circ}F(287.7^{\circ}C)$의 노화온도(老化溫度)에서는 EPDM폴리머의 모든 가교(架橋)가 monosulfide구조가 되나 전가교밀도(全架橋密度) 및 $E_b$ (신장률(伸長率), 절단시(切斷時)의)는 대단(大端)히 낮은 것으로 나타나는데 이것은 산화(酸化)에 의한 노화(劣化)에 기인(基因)되는 것으로 보인다. 질소기류(窒素氣流)속에서의 TGA의 분석결과(分析結果)를 보면 EPDM 가황체(加黃體)는 $800\sim935^{\circ}F(427\sim502^{\circ}C)$의 온도범위(溫度範圍)에서 분해(分解)되며 공기중(空氣中)에서는 $750\sim935^{\circ}F$ 범위(範圍)에서 분해(分解)한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1745-1753
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• 2008

We analyzed the physical and chemical properties such as proximate analysis, ultimate analysis, heating values, thermogravimetric analysis, and combustion test for the organic sludge discharged from chemical and petrochemical product manufacturing industries in the industrial complex. The average combustible and ash content of organic sludges from chemical and petrochemical product manufacturing industries were 17.42%, 7.45%, and 18.25%, 4.22%, respectively. The C, H, O, N, and S compositions for chemical and petrochemical product manufacturing industries were 33.06, 4.34, 24.81, 5.18, and 0.72%. And those compositions for petrochemical product manufacturing industries were 36.58, 4.74, 26.79, 5.09, and 0.49%, respectively. From the TGA test, the minimum temperature for combustion of the sludge discharged from B company was $700^{\circ}C$ for direct use for energy and 2 sludges(F and N companies) were about $600^{\circ}C$. According to the basic combustion test, high concentration of CO was formed because oxidation and pyrolysis reaction take place in the batch type reactor at the same time. From this phenomena we could obtain the significant data for the overheating and breakage of furnace.