• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.313-314
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• 2005

$PbTiO_3$ and PZT(52/48) powders, prepared by the sol-gel method, were mixed with an organic vehicle and the PT/PZT(52/40) heterolayered thick films were fabricated by the screen-printing method on Pt/$Al_2O_3$ substrates. The structural properties such as DTA, X-ray diffraction and microstructure, were examined as a amount of the PbO-$PbF_2$ flux. In the X-ray diffraction analysis, PZT(52/48) thick films showed a perovskite polycrystalline structure without a pyrochlore phase.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.497-499
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• 2005

A portable terminal assistant market grows rapidly every year and it requires many change in research on display devices. Among many newly developing methods, OLED(Organic Light Emitting Diode) is considered an advanced flat display device because its excellent characteristics, including high speed response, full color performance, low power consumption and flux of panel. However changes in the market of display shows that the market will require 3-dimensional images, but it is hard for existing 2-dimensional displays to make 3-dimensional images. Therefore we will try to find various methods such as holograms. In this paper, we will show existing flat displays can make 3-dimensional images by applying Lenticular Screen printing techniques on the organic semiconductor display device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.359-360
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• 2005

PZT(20/80) and PZT(80/20) powders, prepared by the sol-gel method, were mixed with an organic vehicle and the PZT(20/80)/PZT(80/20) heterolayered thick films were fabricated by the screen-printing method on Pt/$Al_2O_3$ substrates. The structural properties such as DTA, X-ray diffraction and microstructure, were examined as a amount of the excess PbO. In the DTA analysis, the formation of the polycrystalline perovskite phase was observed at around $880^{\circ}C$. The average thickness of the PZT heterolayered thick films was approximately $80{\mu}m$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.3
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• pp.245-249
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• 2011

Carbon nanotubes (CNTs) have been significantly used for the field emitters for display applications. However, the lifetime of CNT emitters which are formed by screen printing technique is not guaranteed yet, because the constituents in CNT paste affect the lifetime of CNTs. The CNT pastes for screen printing are normally composed of organic vehicles (nitro cellulose, ethyl cellulose, etc) and additives (glass frits, indium tin oxide (ITO), etc) with CNTs. In this study, the effects of constituents in CNT pastes on the lifetime and emission characteristics of CNTs were investigated by thermal and electrical analysis. Use of glass frits worsened the lifetime and electron emission of CNTs. However, an addition of ITO to CNT paste rather improved the lifetime of CNTs. Degradation of CNTs was small when nitro cellulose was used in CNT paste as an organic vehicle.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.806-808
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• 2004

본 연구에서는 MEMS 공정에 의해 제작된 실리콘 멤브레인 위에 스크린 프린팅법을 이용하여 압전 후막을 제작, 그 특성을 관찰하였다. 실리콘 웨이퍼의 후면을 각각 다른 4가지의 크기로 식각하여 멤브레인을 제작하였다. 제작된 멤브레인 위에 하부전극 Ag-Pd를 스크린 프린팅법으로 형성하고, 그 위에 압전 후막을 스크린 프린팅하여 열처리 하였다. 제작된 압전 후막위에 MFM(Metal-Ferroelectric-Metal)구조의 액츄에이터를 제작하기위해 상부전극으로 Pt를 스퍼터링으로 증착하였다. 제작된 마이크로 액츄에이터는 SEM(Scanning Electron Microscope)으로 구조분석하고, RT66A와 MTI2000으로 동작특성을 해석 하였다.

• The Research Journal of the Costume Culture
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• v.12 no.6 s.53
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• pp.1010-1020
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• 2004

The purposes of this study were to investigate characteristic changes on nonwoven fabric by the charcoal and the yellow soil printing. It separate the grind charcoal and the yellow soil as two different size of particles $45{\sim}52{\mu}m\;and\;53{\sim}65{\mu}m$ for hand screen printing on three kind of nonwoven fabrics. To examine the effect of the charcoal and the yellow soil printing on nonwoven fabric were to observe surface changes by a scanning electron microscope, dyeability by using spectrophotometer, moisture regain by oven method, deodorization and antibacterial activity. The results were as follows: When the charcoal and the yellow soil powder concentration increased from 3 to $9\%$ or from 5 to $10\%$, K/S value also increased from 3.06 to 8.55 or from 1.14 to 1.80. The charcoal and the yellow soil moisture regain also increased. In same concentration, moisture regain occurred higher as particle of small size. In concentration of charcoal $3\%$, rate of deodorization measured as $89\%,\;83\%\;and\;87\%,\;and\;9\%$ concentration caused $96\%,\;86\%\;and\;93\%$ of high deodorization. In concentration of 5, $10\%$ of yellow soil, rate of deodorization measured as $85\%$ over. Antibacterial activity examination in nonfinished nonwoven fabric resulted range of $60\%$, however, $3\%\;and\;9\%$ concentration finished nonwoven fabric resulted $99.9\%$ of excellent antibacterial activity. Also $5\%,\;10\%$ yellow soil concentration was appeared same resoult.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.687-687
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• 2013

In rearpoint contact solar cell and the PERC (passivated emitter rear contact) type cell, surfaces were passivated by SiO2 or Al2O3 to increase solar cell efficiency. Therefore, we have investigated the effect of surface passivation for crystalline silicon solarcell using mass-production atomic layer deposited (ALD) Al2O3. The patttern which consists of cylinders with 100um diameter and 5um height was formed by PR patterning on Si (100) substrate and then Al2O3 of about 10nm and 20nm thickness was deposited by ALD. The pattern in 10 nm Al2O3 film was removed by dipping in aceton solution for about 10 min but the pattern in 20 nm Al2O3 film was not. The influences of process temperature and heat treatment were investigated using microwave photoconductance decay (PCD) and Quasi-Steady-State photoconductance (QSSPC). The solar cell process used in this work combines the advantage of using the applicability of a selective deposition associated with a ALD passivation and the use of low-cost screen print for the contacts formation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.1
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• pp.19-24
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• 2017

In this paper, we propose a textile metamaterial absorber that using screen printing technology. A unit cell of the proposed absorber is motivated from the commercial Chanel logo for wearable applications. The complex impedance of the designed unit cell is analyzed by full-wave simulation. To verify its performance, the proposed metamaterial absorber is fabricated where the silver conductive ink is screen printed on an ordinary textile. From experimental results, the absorptivity of the proposed absorber is around 93 % at 10.8 GHz under normal incidence.

• New & Renewable Energy
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• v.8 no.1
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• pp.18-23
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• 2012

The screen printing has been widely used to form silver electrodes in solar cell device due to their simplicity of process. However, the wavy and irregular surface which is believed to be originated from a screen mask mesh and thixotropic characteristics of paste on screen printing process is well-known to give a negative effect on solar cell efficiency. The dispensing method that the silver paste is extruded through micro nozzle under a moderate pressure and coated on substrate can form the silver electrode without any wavy surface. In this study, we optimize the composition of silver paste and develop paste blending condition based on the thixotropic behavior of paste. The optimized paste shows a large thixotropic loop area which is related to an aspect ratio of electrode line and has the viscosity of 40 $Pa{\cdot}s$ at 40 s-1. The electrode line we finally obtainis 67.2 ${\mu}m$ in width and has an aspect ratio of 0.277.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.9
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• pp.724-727
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• 2009

We have fabricated (Ba,Sr)TiO3$TiO_3$ thick films doped with various amount of ZnBO dopants (1, 3, and 5 wt%) by screen printing method on the alumina substrates, which were sintered at the temperature below $1200^{\circ}C$. With increasing the amount of ZnBO dopants, the relative dielectric permittivity of ZnBO doped (Ba,Sr)$TiO_3$ was decreased, while loss tangent was increased. 1 wt% ZnBO doped (Ba,Sr)$TiO_3$ thick film has relative dielectric permittivity of 759 at 1 MHz, while 3 and 5 wt% of ZnBO doped (Ba,Sr)$TiO_3$ thick films have 624 and 554, respectively. By introducing ZnBO dopants to the (Ba,Sr)$TiO_3$ thick films, leakage current densities were decreased. The decreased leakage current with increasing ZnBO dopants can be explained by increased density and grain size of thick film on alumina substrate. We believe this decreased leakage current density probably come from the increased grain size and increased density.