• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.467-470
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• 2000

This paper present the result of the investigation, electric properties of outdoor insulators with the difference of contaminated condition. In general, the humidity and the amount of soluble salts such as NaCl, MgCl$_2$are the most dominant factor. A mini-fog chamber with transparent acryl and the standard contamination solution with kaoline was used. The kaoline was applied with sprayer to get the specific ESDD and NSDD value, then the specimen was dried and installed horizontally. And to measure the leakage current and the ambient condition, such as relative humidity and temperature, a DAS system was developed with LabView. From the result, we could know the influence of contaminated condition. Contaminated area and pattern has a close relationship with the electrical properties of outdoor insulator.

• Applied Microscopy
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• 제50권
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• pp.13.1-13.7
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• 2020

We examined the morphology of fertilized egg and ultrastructures of fertilized egg envelopes of Ancistrus cirrhosus belong to Loricariidae using light and electron microscopes. The fertilized eggs formed a mass on the spawning place and were yellowish, spherical, non-transparent, demersal, adhesive, and a narrow perivitelline space. But, the adhesiveness of fertilized eggs was disappeared after spawning excluding contact parts. The micropyle with funnel shape was surrounded by 15-19 furrow lines of egg envelope in a spoke-like pattern. The outer surface of egg envelope has smooth side and inner surface of egg envelope was rough with grooves. Also, the total thickness of the fertilized egg envelope was about 32.58 ± 0.85 ㎛ (n = 20), and the fertilized egg envelope consisted of three layers, an outer adhesive electron-dense layer, a middle layer with low electron density and an inner electron-dense layer with grooves in counter structure from other most teleost. Collectively, these morphological characteristics and adhesive property of fertilized egg, and ultrastructures of micropyle, outer surface, and section of fertilized egg envelope are showed species specificity.

• 한국분말재료학회지
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• 제24권6호
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• pp.464-471
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• 2017

A metal mesh TCE film is fabricated using a series of processes such as UV imprinting of a transparent trench pattern (with a width of $2-5{\mu}m$) onto a PET film, filling it with silver paste, wiping of the surface, and heat-curing the silver paste. In this work nanosized (40-50 nm) silver particles are synthesized and mixed with submicron (250-300 nm)-sized silver particles to prepare silver paste for the fabrication of metal mesh-type TCE films. The filling of these silver pastes into the patterned trench layer is examined using a specially designed filling machine and the rheological testing of the silver pastes. The wiping of the trench layer surface to remove any residual silver paste or particles is tested with various mixture solvents, and ethyl cellosolve acetate (ECA):DI water = 90:10 wt% is found to give the best result. The silver paste with 40-50 nm Ag:250-300 nm Ag in a 10:90 wt% mixture gives the highest electrical conductance. The metal mesh TCE film obtained with this silver paste in an optimized process exhibits a light transmittance of 90.4% and haze at 1.2%, which is suitable for TSP application.

• 한국레이저가공학회지
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• 제17권1호
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• pp.1-6
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• 2014

Indium tin oxide (ITO) is an important transparent conducting oxide (TCO). ITO films have been widely used as transparent electrodes in optoelectronic devices such as organic light-emitting devices (OLED) because of their high electrical conductivity and high transmission in the visible wavelength. Finding ways to control ITO micromachining depth is important role in the fabrication and assembly of display field. This study presented the depth control of ITO patterns on glass substrate using a femtosecond laser and slit. In the proposed approach, a gaussian beam was transformed into a quasi-flat top beam by slit. In addition, pattern of square type shaped by slit were fabricated on the surfaces of ITO films using femtosecond laser pulse irradiation, under 1030nm, single pulse. Using femtosecond laser and slit, we selectively controlled forming depth and removed the ITO thin films with thickness 145nm on glass substrates. In particular, we studied the effect of pulse number on the ablation of ITO. Clean removal of the ITO layer was observed when the 6 pulse number at $2.8TW/cm^2$. Furthermore, the morphologies and fabricated depth were characterized using a optical microscope, atomic force microscope (AFM), and energy dispersive X-ray spectroscopy (EDS).

• 한국재료학회지
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• 제21권6호
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• pp.341-346
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• 2011

In this study, we inserted a Zn buffer layer into a AZO/p-type a-si:H layer interface in order to lower the contact resistance of the interface. For the Zn layer, the deposition was conducted at 5 nm, 7 nm and 10 nm using the rf-magnetron sputtering method. The results were compared to that of the AZO film to discuss the possibility of the Zn layer being used as a transparent conductive oxide thin film for application in the silicon heterojunction solar cell. We used the rf-magnetron sputtering method to fabricate Al 2 wt.% of Al-doped ZnO (AZO) film as a transparent conductive oxide (TCO). We analyzed the electro-optical properties of the ZnO as well as the interface properties of the AZO/p-type a-Si:H layer. After inserting a buffer layer into the AZO/p-type a-Si:H layers to enhance the interface properties, we measured the contact resistance of the layers using a CTLM (circular transmission line model) pattern, the depth profile of the layers using AES (auger electron spectroscopy), and the changes in the properties of the AZO thin film through heat treatment. We investigated the effects of the interface properties of the AZO/p-type a-Si:H layer on the characteristics of silicon heterojunction solar cells and the way to improve the interface properties. When depositing AZO thin film on a-Si layer, oxygen atoms are diffused from the AZO thin film towards the a-Si layer. Thus, the characteristics of the solar cells deteriorate due to the created oxide film. While a diffusion of Zn occurs toward the a-Si in the case of AZO used as TCO, the diffusion of In occurs toward a-Si in the case of ITO used as TCO.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.86-86
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• 2010

Micro- and nanoscale texturing and control of surface energy have been considered for superhydrophobicity on polymer and silicon. However these surfaces have been reported to be difficult to meet the robustness and transparency requirements for further applications, from self cleaning windows to biochip technology. Here we provided a novel method to fabricate a nearly superhydrophobic soda-lime glass using two-step method. The first step involved wet etching process to fabricate micro-sale patterns on soda-lime glass. The second step involved application of $SiO_x$-incorporated DLC to generate high intrinsic contact angle on the surface using chemical vapor deposition (CVD) process. To investigate the effect of surface roughness, we used both positive and negative micro-scale patterns on soda-limeglass, which is relatively hard for surface texturing in comparison to quartz or Pyrex glasses due to the presence of impurities, but cheaper. For all samples we tested the static wetting angle and transparency before and after 100 cycles of wear test using woolen steel. The surface morphology is observed using optical and scanning electron microscope (SEM). The results shows that negative patterns had a greater wear resistance while the hydrophobicity was best achieved using positive patterns having static contact angle up to 140 deg. with about 80% transparency. The overall experiment shows that positive patterns at etching time of 1 min shows the optimum transparency and hydrophobicity. The optimization of micro-scale pattern to achieve a robust, transparent, superhydrophobic soda-lime glass will be further investigated in the future works.

• 대한한의진단학회지
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• 제10권2호
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• pp.79-87
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• 2006

Objective : Biologic responses to color stimulation was observed and analyzed in relation with Korean medicine diagnostics. Methods : Twelve volunteers participated and completed the questionnaire on Hanyeol or Joseup patterns of Korean medicine diagnostics. Standard deviation of RR intervals (SDNN), an overall indicator of heart rate variability, was measured while wearing partially transparent acetate film glasses of various colors: (1) transparency or black, (2) red, green, or blue, or (3) cyan, or yellow. Results : Different responses to the color environmental stimulation were observed. Yeol pattern score was inversely related with the SDNN value under red color stimulation. Conclusion : This line of observations may serve as a basis of clinical application of color therapy, in particular, in relation with pattern diagnosis of Korean medicine, and may be applied in combination with existing electrodermal meridian measurement systems for better evaluation of Gi (life energy) phenomenon.

• 접착 및 계면
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• 제18권2호
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• pp.59-67
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• 2017

스마트 모바일 산업의 성장에 따라 부품의 집적화가 가속화 되고 있다. 이러한 부품의 집적화는 부품간의 간섭현상문제를 야기했으며, 이를 해결하기 위한 전자파 차폐 기술의 중요성이 부각되고 있다. 전자파 차폐 기술은 전자파를 반사하거나 흡수하는 방식으로 구현되며, 일반적으로 전도성물질이 전자파 차폐에 활용된다. 최근 산업의 변화에 따라 투명 차폐기술이 요구되고 있으며, 본 연구에서는 임프린팅 기술을 활용한 음각 구조 패턴에 전도성 복합 바인더를 충진 하여 투명 차폐소재를 제안하고자 하였다. 전도성 복합 바인더를 제조하기 위하여 UV 중합 아크릴 바인더를 활용하고 전도성 부여를 위해 구상, 판상 및 적층상의 은 입자를 활용하였다. 은 입자의 구조적인 특징에 따라 경화특성, 전도성 그리고 접착력의 변화를 확인하였다. 경화과정에서는 구상 입자의 활용이 가장 효율적이었으며, UV에 취약한 구조를 보완할 추가적인 경화 시스템이 요구되었다. 전도성평가에서는 적층상 구조가 우수한 특성을 보였다. 접착력은 구상이 가장 우수한 특성을 보였으며, 표면에서의 불규칙성에 따른 결과로 평가된다. 최종적으로 이를 활용한 패턴필름은 우수한 투명특성을 보여주었다.

• 한국정보전자통신기술학회논문지
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• 제16권1호
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• pp.8-17
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• 2023

기존 liquid crystal display(LCD) 공정에서 Indium Tin Oxide(ITO) 투명전극과 폴리이미드 배향막의 러빙 공정은 액정을 정렬하고 전계를 인가하기 위하여 필수적인 공정이다. 하지만 ITO의 증착은 높은 진공을 요구하며, 러빙 공정은 정전기에 의해 소자가 손상될 수 있는 단점이 존재한다. 본 논문에서는 기존 ITO 투명전극을 대체하기 위하여 PEDOT:PSS와 Multi-wall carbon nanotube(MWNT)를 혼합하여 PEDOT:PSS 나노복합체를 제조하고, 러빙 공정을 대체하기 위하여 나노 주름 구조 몰드를 통한 나노임프린팅을 통하여 박막을 형성함으로써 기존 액정 디스플레이의 투명전극과 배향막 두 가지 박막을 PEDOT:PSS/MWNT 나노복합체 박막 하나만으로 기능하게 하여 공정을 단순화 하였다. 전사된 나노 주름을 따라 액정이 잘 배향됨을 확인하였으며, 이를 기반으로 만들어진 액정 셀에서 박막 내 MWNT의 함량이 높아질수록 박막의 전기전도도가 증가하여 낮은 구동 전압과 빠른 응답 속도를 갖는다는 것을 확인하였다. 본 연구를 통해 공정 단순화와 용액공정에 의한 공정 단가 절감, 기존 러빙 공정의 단점을 해결하는데 기여 할 수 있을 것으로 기대된다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제32권4호
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• pp.258-267
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• 2005

본 논문에서는 사용자의 발걸음 정보를 이용하여 유비쿼터스 컴퓨팅 환경 중 가정과 같이 규모가 크지 않은 곳에서 사용자의 위치 추적 및 인식이 가능한 유비플로어 시스템을 제안한다. 유비쿼터스 환경에서 개인화 된 위치 기반 서비스를 제공하기 위해서는 사용자 및 위치 정보가 반드시 필요하다. 기존의 시스템은 이를 위해서 태그등의 센서를 휴대하거나 카메라등의 비접촉 센서를 사용하였다. 그러나 이들은 사용자에게 불편함을 주거나 주변 노이즈에 민감한 단점이 있다. 이를 극복하기 위해, 사용자가 걸을 때의 지면 반력을 이용한 플로어-기반의 인증 시스템이 제안되었으나 시스템을 구성하는 센서와 주변 기기가 비싸다는 단점이 있다. 제안된 시스템은 싼 ON/OFF 스위치 센서들을 사용해 일상생활에서 걷는 사용자의 발걸음 패턴을 파악하여 사용자를 인증한다. 성인 남녀 10명을 대상으로 실험하여 평균 $90\%$ 의 인식률을 잃었으며, 사용자는 인증받기 위해 특별한 장치의 착용이나 특정한 행동을 취할 필요가 없다.