• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.6
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• pp.462-467
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• 2013

In this paper, we analyzed the effects of doctoring process on the patterns of Ag ink in gravure off-set printing. The parameters of doctoring process were the angle and the pressure, which was represented by the depth of blade movement to the gravure roll, of doctor blade to the surface of gravure roll, and the angle of patterns engraved on the gravure roll to the doctor blade moving direction. The proper parameters were extracted for the fine patterns and they were 15 mm for the pressure, $60^{\circ}$ for the blade angle. And the angle of patterns with respect to the blade movement should be less than $40^{\circ}$ for the best results. The gravure off-set printing with the above parameters was carried out to print gate electrodes and scan bus lines of OTFT-backplane for e-paper. The line width of $50{\mu}m$ was successfully obtained. The thickness of electrodes was $2.5{\mu}m$ and the surface roughness was $0.65{\mu}m$ and the sheet resistance was $15.8{\Omega}/{\Box}$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.4
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• pp.298-302
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• 2010

We investigated the resistance change behavior of SABiT (Samsung Advanced Bump interconnection Technology) technology-applied PCB (Printed Circuit Board) with the various bump sizes and fabrication conditions. Many testing samples with different bump size, prepreg thickness, number of print on the formation of Ag paste bump, were made. The resistance of Ag paste bump itself was calculated from the Ag paste resistivity and bump size, measured by using 4-point probe method and FE-SEM (Field Emission Scanning Electron Microscope), respectively. The contact resistance between Ag paste bump and conducting Cu line were obtained by subtracting the Cu line and bump resistances from the measured total resistance. It was found that the contact resistance drastically changed with the variation of Ag paste bump size and the contact resistance had the largest influence on total resistance. We found that the bump size and contact resistance obeyed the power law relationship. The resistance of a circuit in PCB can be estimated from this kind of relationship as the bump size and fabrication technique vary.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.46-50
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• 2004

인쇄/소결 방법으로 가시영역에서 광감도가 매우 큰 CdSSe 다결정 후막을 만들고 이를 이용하여 광전도 젤을 제작하였다. 후막의 낱알 크기는 $5{\mu}m$ 정도이였다. 광전도 셀은 소결 촉진제로 첨가한 $cucl_2$ 양이 CdSSe 1 g 당 3.06~0.10 mg 정도이변 감도, 광전류와 암전류의 비율이 각각 0.7과 $10^5$ 이상을 나타내었고, Cds 와 CdSe 의 질량비가 1:0, 9:1, 8:2, 7:3, 6:4, 5:5일 때 응답파장은 각각 500nm, 520nm, 540nm, 570nm, 620nm, 660nm였다. 또한 주파수 특성을 나타내는 응답시간은 오름시간과 감쇠시간이 각각 30관 20ms 정도 이였으며 최대허용 소비 전력은 80mw 이상이었다. 이상과 같이 인쇄/소결 방법으로 제작된 광전도 셀은 $cucl_2$ 양이 CdSSe 1g 당 0.06~0.10 mg 정도 주입되면 센서로써 좋은 특성을 나타내었다.

• Korean Journal of Materials Research
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• v.27 no.2
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• pp.82-88
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• 2017

Ink-jet printing techniques with ceramic ink, which contains ceramic pigments as colorant, are in increasingly use in the ceramic industry. Generally, ceramic pigments that are produced by conventional method show diameters of several micrometers; these micrometer sized particles in the ink-jet printing process can cause undesirable behavior such as print head nozzle clogging. To prevent this problem, a particle size reduction process is required. In this study, CMYK (cyan, magenta, yellow, black) pigments were synthesized via solid state method. Each pigment particle was milled to submicron size by an attrition mill. The effects of micronizing on the morphology, mechanical property, crystal structure and color property of the CMYK ceramic pigments were investigated by field emission scanning electron microscopy (FE-SEM), particle size analysis (PSA), X-ray diffraction (XRD) and CIE $L^{\ast}a^{\ast}b^{\ast}$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11b
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• pp.15-17
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• 2004

The quality of X -ray image is depending on the acquired signal pattern So far, the MTF(modulation transfer function) of medical image system has been obtained through various kinds of calculationprocesses after using SWRF (A square wave response function method) to print out it into films. In this study, a tool has been developed that can help the actual user who actually creates the medical images measure the MTF of the finaldisplay image very simply by applying Borland C++ builder software as well as LEAD tools software for the SWRF calculation process to analyze the MTF even on the display image. Films have been printed out by this newly developed MTF measuring tool under the same conditions with the ones for the existing tools and also the calculation method has shown no difference with any existing SWRF calculation method. By using this, it was found out that the MTF of the resolving power of the computed radiography(CR) Image plate (IP) that is a conventional X-ray detection system Jar the conventional X-ray purpose was about 10% at the range of 3.00 LP/mm.

• Journal of the Korean Ceramic Society
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• v.56 no.5
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• pp.461-467
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• 2019

Ink-jet printing technology, which utilizes a digitalized design to print fine ink directly on a substrate, has been of interest in various industries due to its high efficiency and adaptability to various materials. Recently, active attempts have been made to apply ceramic materials having excellent heat resistance, light resistance, and chemical resistance to the ink-jet printing process. In this study, ceramic ink was synthesized by combining ceramic pigments with UV curable polymer. 3D printability at various contact angles between ceramic ink and substrate was analyzed in detail. Rheological properties of the synthesized ceramic ink were optimized to meet the requirements of the ink-jet printing process, and the contact angle of UV curable ceramic ink was controlled through surface treatment of the substrate. The potential for additive manufacturing of ceramic material using ink-jet printing was investigated by analyzing the effect of contact angle control on ceramic ink droplets and their 3D printability.

• Korean Institute of Interior Design Journal
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• v.14 no.4 s.51
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• pp.79-86
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• 2005

According to the new multi-media appeared as a result of rapid growth of the information and science technique, the school library must be changed to the integration of the teach-study media resource from the existing print media. It means that the school library has to play a role of the study center with a different media from the existing teaching material, teaching instrument, facility and opportunity. The Information education must be conducted in the way of an integrated education course and able to do both information transaction and problem settlement. The education facility to solve this problem is the school library. Therefore, the school library becomes important more and more. It means that the school library is the center of entire study and education material for the teacher and student is focused on it. It is urgent to make the standard of the school library In order to cope with the new education and information environments. And especially it is very important to make a plan about the location and scale of the school library to improve the quality of the children's studying activity. The location of the school library is decided under consideration of the relationship with other room of school house and the proper scale of it is between 2.5units and 7.0units of classroom based on the number of class.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.345-345
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• 2007

본 연구는 x선 영상검출기 적용을 위한 $HgI_2$ 필름의 누설전류 특성 향상을 위한 연구로서, $HgI_2$기반의 다양한 물질을 이용하여 다층구조 방식으로 제작된 필름의 누설전류 특성평가 및 제작된 다층구조의 상부전극물질의 변화에 따른 누설전류 특성을 평가하였다. $HgI_2$기반 다층구조의 제작 물질은 Parylene, $PbI_2$, a-Se을 사용하여 시편(parylene/ITO, ITO/$HgI_2/PbI_2$/ITO, ITO/$HgI_2$/a-Se/ITO)을 제작하였으며, 필름 제작공정은 Screen print, PVD공정으로 다층구조 필름을 제작하였다. 또 한, 다층구조로 제작된 필름에 상부 전극물질은 Au, In, ITO를 사용하여 누설전류의 특성을 평가하였다. 측정 장치로 DC Power Supply(556H. EG&G : 50~200V), X 선 발생장치(Toshiba KXO-50N), 차폐체 (Al 및 Cu), Oscilloscope (LeCroy, LC334AM, USA), Electrometer (Keithley, 6517), Ion chamber 2060 (Radical Co.)을 이용하여, 제작된 $HgI_2$기반 다층구조 sample의 누설전류 특성을 실험하였다. 이 결과로 다층구조에 제작된 물질 및 상부전극에 따른 누설전류의 특성을 평가하였다.

• Progress in Superconductivity and Cryogenics
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• v.24 no.1
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• pp.8-12
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• 2022

Recently, research on applying composite materials to various industrial fields is being actively conducted. In particular, composite materials fabricated by Fused Deposition Modeling 3D printers have more advantages than existing materials as they have fewer restrictions on manufacturing shape, reduce the time required, weight. With these advantages, it is possible to consider utilizing composite materials in cryogenic environments such as the application of liquid oxygen and liquid hydrogen, which are mainly used in an aerospace and mobility. However, FDM composite materials are not verified in cryogenic environments less than 150K. This study evaluates the characteristics of composite materials such as tensile strength and strain using a UTM (Universal Testing Machine). The specimen is immersed in liquid nitrogen (77 K) to cool down during the test. The specimen is fabricated using 3D print, and can be manufactured by stacking reinforced fibers such as carbon fiber, fiber glass, and aramid fiber (Kevlar) with base material (Onyx). For the experimental method and specimen shape, international standards ASTM D638 and ASTM D3039 for tensile testing of composite materials were referenced.

• IE interfaces
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• v.7 no.1
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• pp.67-74
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• 1994

In this study, we propose an integrated CAD(Computer Aided Design) library database in a heterogeneous commercial ECAD(Electronic CAD) environment. To effectively solve engineering problems focused on BOM data extraction we use a software system called schematic capture and company-wide standard electronic part information loaded on different commercial ECADs. We unify many commercial ECADs into one schematic capture and a variety of PCB(Printed Circuit Board) design tools. For this purpose we develope a model for linking CAD symbol library with company-wide standard part information. We also develope a schematic design data conversion scheme and show how to extract PBA level BOM data using our customized schematic capture. This system is being operated in an X-Window based engineering work station and commercial RDBMS base.