• Corrosion Science and Technology
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• 제7권5호
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• pp.269-273
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• 2008

It is known that the fluoric resin has the most outstanding properties in the extremely acidic environment of high temperature. However, this resin is the thermal hardening type that needs long time heat treatments above $250^{\circ}C$. It's impossible to use in situ in the extremely acidic environment such as a huge FGD ductworks or industrial chemical tanks. Furthermore, even the natural hardening type fluoric coatings which can be hardened less than $120^{\circ}C$ can not be applied to the highly acidic environmental plants because of its chemical resistance. In this study, new fluoric coatings that has excellent thermal resistance, chemical resistance and corrosion resistance has been developed in order to solve above problems and to be applied to the large plant structures in the field. These newly developed coatings are organic and inorganic composite type that have fluoric rubber(100 wt%), fluoric resin(5~50 wt%), oxalates(5~30 wt%), inorganic fillers mixed with plate-type and bulk-type solids(20~150 wt%), hardeners(0.5~5 wt%), and hardening hasteners(0.1~3 wt%). The best chemical and physical properties of these coatings are acquired by variation of adhesive reinforcement agents, dispersants, leveling agents. Mixing ratios of plate-type and bulk-type inorganic fillers influence the thermal properties, abrasive resistance and chemical infiltration properties of coatings. The mixing control is also very important to have homogeneous surface and removing inner voids of coatings.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4317-4328
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• 2023

To ensure the measuring accuracy of the wall temperature, the outer wall temperature measurement values by using three kinds of thermocouple welding methods were analyzed and evaluated in the paper, including single-point flush-mounted in the wall groove method, single-point insert-mounted in the wall groove, and outer surface direct welding method, based on the application of a tube-in-tube condensing heat exchanger. And the impacts of silver, tin, and thermal resistance adhesive as filling materials on wall temperature measurement were also investigated, and the results were compared to that obtained without filling materials. The results showed that the wall temperatures measured by the three welding methods were lower than the theoretically calculated value. And the wall temperature measured by the outer surface direct welding method was lowest under the same experimental conditions. The wall temperatures measured by single-point flush-mounted and insert-mounted in the wall groove methods were also affected by different welding filling materials. It was found that the greater the thermal resistance of filling materials, the smaller the heat loss. By analyzing the reasons for the low measured value of wall temperature, a new wall temperature measurement method was developed to improve the accuracy of the current measurement method. Meanwhile, the outer wall temperature measurement experiments of vertical and horizontal heat transfer tubes were carried out to validate and calibrate the improved outer wall temperature measurement method. The results showed that the average outer wall temperature deviation measured by the improved wall temperature measurement method ranged from - 0.82% to +2.29% for vertical tubes and - 4.75% to - 1.44% for horizontal tubes, and the improved measurement method had good measurement accuracy.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2222-2227
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• 2007

Newly structured metal-supported solid oxide fuel cell was fabricated and characterized by impedance analysis and galvanodynamic experiment. Using a cermet adhesive, thin ceramic layer composed of anode(Ni/YSZ) and electrolyte(YSZ) was joined with STS430 metal support of which flow channel was fabricated. $La_{0.8}Sr_{0.2}Co_{0.4}Mn_{0.6}O_3$ perovskite oxide was used as cathode material. Single cell performance was increased and saturated at operating time to 300hours at 800$^{\circ}C$ because of cathode sintering effect. The sintering effect was reinvestigated by half cell test and exchange current density was measured as 0.005A/$cm^2$. Maximum power density of the cell was 0.09W/$cm^2$ at 800$^{\circ}C$. Numerical analysis was carried out to classify main factors influencing the single cell performances. Compared to experimental IV curve, simulated curve based on experimental parameters such as exchange current density was in good agreement.

• 공업화학
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• 제5권5호
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• pp.851-856
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• 1994

무용제 타입의 hot melt계 중 styrene-isoprene-styrene(SIS) 블럭공중합체에 대한 tackifier resin의 상용성과 점탄성, 그에 영향을 미치는 점착물성에 관해 조사하였다. SIS블럭공중합체의 이소프렌상에서는 $C^5$ petroleum resin이 상용성이 우수하며, coumarone-indene resin은 전혀 상용성을 보이지 않았다. 그에 따른 점착력, 초기점착력, 견지력 등의 점착물성은 $C^5$ petroleum resin>rosin ester resin>coumarone-indene resin순으로 나타났으며, 고무상에서 상용성이 우수한 tackifier resin이 효과적임을 알았다. 한편, 이때의 저장탄성률(G')에서, plateau modulus값이 $1{\times}10^6-3{\times}10^6dyn/cm^2$일때 점착력이 가장 우수하였다.

• Transactions on Electrical and Electronic Materials
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• 제8권2호
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• pp.89-92
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• 2007

$CuInSe_2$ thin film were prepared in order to clarify optimum conditions for growth of the thin film depending upon process, and then by changing a number of deposition conditions and heat treatment conditions variously, structural and electrical characteristics were measured. Thereby, optimum process variables were derived. For the manufacture of the $CuInSe_2$, Cu, In and Se were deposited in the named order. Among them, Cu and In were deposited by using the sputtering method in consideration of their adhesive force to the substrate, and the DC/RF power was controlled so that the composition of Cu and In might be 1:1, while the annealing temperature having an effect on the quality of the thin film was changed from $200\;^{\circ}C$ to $350\;^{\circ}C$ at intervals of $50\;^{\circ}C$.

• Transactions on Electrical and Electronic Materials
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• 제14권1호
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• pp.20-23
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• 2013

When applying superconducting wire to power machines, an investigation needs to be carried out on the characteristics of wire phase changes in connection with the insulating layer. This study examined trends in the increase of the wire's resistance and the characteristics of its recovery from quenching by a current-applied cycle at temperatures of 90 K, 180 K, and 250 K. The procedure was conducted based on the thickness and presence (or absence) of the insulating wire layers. To achieve this, YBCO thin-film wires with the same critical temperatures were prepared with copper and stainless steel stabilizing layers. At levels (-one, three, and five-), with superior performance, polyimide pressure-sensitive adhesive tape was attached to the wires at a very low temperature. The eight prepared test samples were wound around the linear frames. The wire's voltage and current created from the phase change characteristics were measured at the wire's prescribed temperature, using the four-point probe method. The wire's resistance and recovery characteristics were examined for each cycle at temperatures of 90 K, 180 K, and 250 K.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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• pp.86-90
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• 2008

$CuInSe_2$ thin film were prepared in order to clarify optimum conditions for growth of the thin film depending upon process, and then by changing a number of deposition conditions and heat treatment conditions variously, structural and electrical characteristics were measured. Thereby, optimum process variables were derived. For the manufacture of the $CuInSe_2$, Cu, In and Se were deposited in the named order. Among them, Cu and In were deposited by using the sputtering method in consideration of their adhesive force to the substrate, and the DC/RF power was controlled so that the composition of Cu and In might be 1:1, while the annealing temperature having an effect on the quality of the thin film was changed from $200^{\circ}C$ to $350^{\circ}C$ at intervals of $50^{\circ}C$.

• Current Photovoltaic Research
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• 제4권2호
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• pp.59-63
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• 2016

A key point of a soldering process for photovoltaic (PV) modules is to increase an adhesive strength leading a low resistivity between ribbon and cell. In this study, we intended to optimize a heating condition for the soldering process and characterize the soldered joint via physical and chemical analysis methods. For the purpose, the heating conditions were adjusted by IR lamp power, heating time and hot plate temperature for preheating a cell. Since then the peel test for the ribbon and cell was conducted, consequently the peel strength data shows that there is some optimum soldering condition. In here, we observed that the peel strength was modified by increasing the heating condition. Such a soldering property is affected by a various factors of which the soldered joint, flux and bus bar of the cell are changed on the heating condition. Therefore, we tried to reveal causes determining the soldering property through analyzing the soldered interface.

• Elastomers and Composites
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• 제35권4호
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• pp.296-302
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• 2000

신발 중창용 EVA 발포체의 수용성 폴리우레탄계 접착제에 대한 접착력을 증가시키기 위하여 발포체 표면을 저온 플라즈마 처리하였다. 플라즈마 처리기체 종류, 플라즈마 처리시간, 전극과 시료와의 거리등의 조건에 따른 발포체의 표면형태, 접촉각 및 수성폴리우레탄에 대한 접착력 등을 주사전자현미경, 접촉각 측정기, 인장강도시험기 등을 사용하여 측정하였다. 플라즈마 처리시간이 증가함에 따라 플라즈마 에칭에 의한 표면 형태의 변화가 더욱 뚜렷하게 나타났으며, 물로 측정한 발포체의 표면 접촉각은 현저히 감소하였다. 플라즈마 처리시간이 증가함에 따라 접착력은 현저히 증가하였다.

• 마이크로전자및패키징학회지
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• 제21권3호
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• pp.1-6
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• 2014

차세대 전자소자는 입출력(I/O) 핀 수의 증가, 전력소모의 감소, 소형화 등으로 인해 fine-pitch 배선 시스템이 요구되고 있다. Fine-pitch 특히 10 um 이하의 fine-pitch에서는 기존의 무연솔더나 Cu pillar/solder cap 구조를 사용할 수 없기 때문에 Cu-to-Cu bumpless 배선 시스템은 2D/3D 소자 구조에서 매우 필요한 기술이라 하겠다. Bumpless 배선 기술로는 BBUL 기술, 접착제를 이용한 WOW의 본딩 기술, SAB 기술, SAM 기술, 그리고 Cu-to-Cu 열압착 본딩 기술 등이 연구되고 있다. Fine-pitch Cu-to-Cu interconnect 기술은 연결 방법에 상관없이 Cu 층의 불순물을 제거하는 표면 처리 공정, 표면 활성화, 표면 평탄도 및 거칠기가 매우 중요한 요소라 하겠다.