• 전자공학회논문지 IE
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• v.43 no.4
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• pp.99-104
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• 2006

The Langmuir-Blodgett(LB) technique has attracted considerable interest in the fabrication of electrical and electronic devices. Maxwell displacement current (MDC) measurement has been employed to study the dielectric property of Langmuir-films. MDC flowing across monolayers is analyzed using a rod-like molecular model. A linear relationship between the monolayer compression speed u and the molecular area Am. Compression speed a was about 30, 40, 50mm/min. Langmuir-Blodgett(LB)layers of Arachidic acid deposited by LB method were deposited onto slide glass as Y-type film. The structure of manufactured device is Au/Arachidic acid/Al, the number of accumulated layers are 9$\sim$21. Also, we then examined of the Metal-Insulator-Metal(MIM) device by means of I-V. The I-V characteristics of the device are measured from -3 to +3[V]. The insulation property of a thin film is better as the distance between electrodes is larger.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1202-1203
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• 2015

This paper describes the development of HVDC ${\pm}500kV$ polypropylene laminated paper (PPLP) mass-impregnated (MI) type cable system for HVDC transmission lines. As you know, mass-impregnated type cable generally has only insulating layer with the Kraft paper impregnated with a high-viscosity insulating compound. But polypropylene laminated paper is made of a layer of extruded polypropylene (PP) film sandwiched between two layers of Kraft paper. Thanks to PP film and its combination with Kraft paper, PPLP has higher AC, Impulse (Imp.) and DC breakdown (BD) strengths as well as lower dielectric loss than conventional Kraft paper insulation. In addition, Kraft MI cable has a limitation for the maximum conductor temperature as $55^{\circ}C$ But this PPLP MI cable has higher maximum conductor temperature than that of Kraft MI cable due to advantage of oil drainage characteristics. It is the most economic type of cable for HVDC transmission. Also HVDC ${\pm}500kV$ PPLP MI cable system was developed including land joints and outdoor-terminations. In order to prove the mechanical and electrical performances, the type test was carried out according to CIGRE recommendations. A full scale cable system has been tested successfully. And additional load cycle and polarity reversal tests on the cable system showed a higher performance compared with a similar mass impregnated paper cable.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.71-71
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• 2012

As the critical dimensions of integrated circuits are scaled down, the line width and spacing between the metal interconnects are made smaller. The dielectric film used as insulation between the metal lines contributes to the resistance-capacitance (RC) time constant that governs the device speed. If the RC time delay, cross talk and lowering the power dissipation are to be reduced, the intermetal dielectric (IMD) films should have a low dielectric constant. The introduction of Cu and low-k dielectrics has incrementally improved the situation as compared to the conventional $Al/SiO_2$ technology by reducing both the resistivity and the capacitance between interconnects. Some of the potential candidate materials to be used as an ILD are organic and inorganic precursors such as hydrogensilsequioxane (HSQ), silsesquioxane (SSQ), methylsilsisequioxane (MSQ) and carbon doped silicon oxide (SiOCH), It has been shown that organic functional groups can dramatically decrease dielectric constant by increasing the free volume of films. Recently, various inorganic precursors have been used to prepare the SiOCH films. The k value of the material depends on the number of $CH_3$ groups built into the structure since they lower both polarity and density of the material by steric hindrance, which the replacement of Si-O bonds with Si-$CH_3$ (methyl group) bonds causes bulk porosity due to the formation of nano-sized voids within the silicon oxide matrix. In this talk, we will be introduce some properties of SiOC(-H) thin films deposited with the dimethyldimethoxysilane (DMDMS: $C_4H_{12}O_2Si$) and oxygen as precursors by using plasma-enhanced chemical vapor deposition with and without ultraviolet (UV) irradiation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11b
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• pp.27-32
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• 2004

Maxwell displacement current (MDC) measurement has been employed to study the dielectric property of Langmuir-films. MDC flowing across monolayers is analyzed using a rod-like molecular model. A method for determining the dielectric relaxation time ${\tau}$ of floating 'monolayers on the water surface is presented. MDC floing across monolayers is analyzed using a rod-like molecular model. It is revealed that the dielectric relaxation time ${\tau}$ of monolayers in the isotropic polar orientational phase is determined using a liner relationship between the monolayer compression speed a and the molecular area Am. Compression speed a was about 30,40,50mm/min. LB layers of Arachidic acid deposited by LB method were deposited onto slide glass as Y-type film.The physicochemical properties of the LB films were examined by UV absorption spectrum, SEM and AFM. The structure of manufactured device is Au/Arachidic acid/Al, the number of accumulated layers are 3~9. Also, we then examined of the MIM device by means of I-V characteristic of the device is measured from -3 to +3[V]. The insulation property of a thin film is better as the distance between electrodes is larger.

• Journal of the Korean Society for Railway
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• v.19 no.1
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• pp.1-10
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• 2016

To improve the sound insulation performance of laminated glass in high speed trains, it is beneficial to study the relationship between the characteristics of interlayer films and the acoustical performance. In addition to those of conventional PVB (polyvinyl butyral), the dynamic mechanical properties of PVB derivatives and PC (polycarbonate), which are candidates for interlayer films, were analyzed. We assumed that PVB-HEMU, which has a glass transition temperature ($T_g$) around room temperature and a large tan ${\delta}$ (loss tangent) value, can be made to damp efficiently. The damping capability was tested utilizing sound transmission loss measurement and simulation under the identical structure of laminated glass in high speed trains. We also built a database for analysis of relations between interlayer film characteristics and acoustical performance; this was followed by the determination of sound transmission loss using the intensity technique and FEA.

• KIEAE Journal
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• v.16 no.4
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• pp.41-46
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• 2016

Purpose: This is a study on the planning of temporary housing for post application of Mega Sports facilities. The subject of the study is 2018 Pyeongchang Winter Olympics, which is to suggest building an alternative temporary housing using shipping containers(high cube), which solve the lack of accommodations and recycle temporary housing after Olympics, save money and be eco-friendly in Olympics. Method: This study includes this ; research on the a fact-finding survey about Mega sports facilities post application and demand survey on 2018 Pyeongchang Winter Olympics accomodations and an analysis about temporary housing plan. Furthermore we decided temporary housing building plan by analyzing residents' needs and traits of the housing etc. Through this, we made a schematic design for household units. Result: As a result, this study is a plan of making space, forms, and structure. The planned size is $38.4m^2$(L:12m, W:3.2m) except balcony, and indoor height is 2.5m. The space consists of entrance, bathroom, bedroom and living room with folding furniture system. Also there's a detailed floor plan of the ceiling, wall, and floor we drew up. The ceiling and wall consist of dampproof film, noncombustible board, fire proof urethane form, and color-designed sheet. The floor is composed of floor tile, cement mortar, light concrete(with heat coil), insulation, and dampproof film. Additionally, this study is a plan of interior dry wall with detail using modular construction method for work efficiency and quality improvement.

• Journal of the Korean Ceramic Society
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• v.52 no.5
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• pp.366-373
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• 2015

Sol-gel binder was prepared by hydrolysis and condensation reaction using boehmite sol and methyltrimethoxysilane as a function of aging-time. The coating slurry was composed of a plate-shape alumina in the sol-gel binder for the EPD process, in which particles dispersed in the slurry were deposited on the electrode under an electric field due to the surface charge. We studied the effects of three parameters: the content of boehmite, the aging time, and the applied voltage, on the physical, thermal, and electrical properties of the hybrid composite films by EPD. The amount of boehmite was 10 ~ 20 wt% and the aging time was 0.5 ~ 72, with a fixed amount of plate-shape alumina of 10 wt%. The condition of applied voltage was 5 ~ 30 V with a distance of 2 cm between the electrode during the EPD process. We confirmed that a structure of hybrid composite films of well-ordered plate alumina was deposited on the substrate when the film was prepared using a sol-gel binder composed of 15 wt% boehmite with 1 hr aging time and EPD at 10 V. The process shows a weight loss of 7% at $500^{\circ}C$ in TGA and a breakdown voltage of 8 kV at $87{\mu}m$.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.519-524
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• 2019

Even though stainless steel foil is not a highly efficient material for film-type solar cell, it has strong passivation capability without additional process. In this study, silicone resin was employed during a-Si:H thin film solar cell fabrication for the purpose of planarization and electrical insulation. In the first stage of process, silicone resin was coat onto the stainless steel (STS) using spin coater with thickness of $2{\sim}3{\mu}m$ and followed by aluminum deposition using ion beam application. Unexpectedly buckling was formed during aluminum deposition process. After subsequent fabrication processes, solar cell performance was evaluated. In voltage-current data, slight increase of cell performance was obtained and interpreted by the increase of light scattering.

• Journal of Bio-Environment Control
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• v.21 no.1
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• pp.1-11
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• 2012

The objective of the present study is to provide data needed to find double covering method to be able to improve environment of temperature, humidity and PPF in tomato greenhouse. The distribution charts of temperature, humidity and PPF which were measured in environment control conditions such as thermal insulation, air heating, roof ventilation and air fog cooling in conventional and air inflated double layers greenhouses were drawn and analysed. The thermal insulation effect of the air inflated greenhouse was the same as that of conventional greenhouse because the temperature between insulation curtain and roof covering material was equal in heating season. The ventilation effect of the air inflated greenhouse was superior to the conventional greenhouse. The temperature distribution in the fog cooled greenhouse was uniform and the cooling effect was about $3.5^{\circ}C$. The condensation on the roof covering surface could be controlled by removing the moisture between insulation curtain and roof covering by using humidifier. The PPF of conventional greenhouse was more decreased than the air inflated greenhouse as time went by because the transmittance of conventional greenhouse declined by dust collected on the inside plastic film owing to rolling up and down operation for ventilation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.429-429
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• 2007

For various applications of liquid crystal displays (LCDs), the uniform alignment of liquid crystal (LC) molecules on treated surfaces is significantly important. Generally, a rubbing method has been widely used to align the LC molecules on polyimide (PI) surfaces. Rubbed PI surfaces have suitable characteristics, such as uniform alignment. However, the rubbing method has some drawbacks, such as the generation of electrostatic charges and the creation of contaminating particles. Thus, we strongly recommend a non contact alignment technique for future generations of large high-resolution LCDs. Most recently, the LC aligning capabilities achieved by ultraviolet and ion-beam exposures which are non contact methods, on diamond-like carbon (DLC) inorganic thin film layers have been successfully studied because DLC thin films have a high mechanical hardness, a high electrical resistivity, optical transparency, and chemical inertness. In addition, nitrogen-doped DLC (NDLC) thin films exhibit properties similar to those of the DLC thin films and a higher thermal stability than the DLC thin films because C:N bonding in the NDLC thin filmsis stronger against thermal stress than C:H bonding in the DLC thin films. Our research group has already studied the NDLC thin films by an ion-beam alignment method. The $SiN_x$ thin films deposited by plasma-enhanced chemical vapor deposition are widely used as an insulation layer for a thin film transistor, which has characteristics similar to those of DLC inorganic thin films. Therefore, in this paper, we report on LC alignment effects and pretilt angle generation on a $SiN_x$, thin film treated by ion-beam irradiation for various N ratios