• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.999-1002
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• 2003

Electrooptical (EO) characteristics of a new multidomain vertical-alignment (MVA) liquid crystal display (LCD) with negative dielectric anisotropy on a homeotropic photopolymer were studied. Good voltage-transmittance (V-T) curves of the new MVA-LCD on the homeotropic photopolymer were obtained. Also, the stable response time of the new MVA-LCD on the homeotropic photopolymer was achieved. The viewing angle of the new MVA-LCD could be improved by a crossed stripe grating-groove surface as the alignment layer using a photolithograph method on the photopolymer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.3
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• pp.219-223
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• 2003

The electro-optical (EO) performances of a multidomain verticial-alignment (MYA) cell on a homeotropic photopolymer have been investigated. In the absence of an electric field, the WVA cell achieved black state as LC alignment is homeotropic An electric field created by interdigitated electrodes and rib made after photolithograph using the photopolymer on both substrates causes a director deformation of a multidomain type. Good voltage transmittance curves for a MVA cell on the homeotropic photopolymer were observed. Also, the stable response time of MYA cell on the homeotropic photopolymer can be achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.953-956
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• 2002

The electro-optical (EO) performances of a multidomain vertical-alignment (MVA) cell on a homeotropic photopolymer have been investigated. In the absence of an electric field, the MVA cell achieved black state as LC alignment is homeotropic. An electric field created by interdigitated electrodes and rib made after photolithograph using the photopolymer on both substrates causes a director deformation of a multidomain type. Good voltage-transmittance curves for a MVA cell on the homeotropic photopolymer were observed. Also, the stable response time of MVA cell on the homeotropic photopolymer can be achieved.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.750-753
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• 2002

At present, almost circuits are wired using copper in flexible circuits. But, these circuit have limit to flexibility so it occurs fracture about cyclic bending and, thermal load of bending stress occur a circuit trouble. a study of all-polymer flexible circuits get over that problem. Established fabrication method of all-polymer circuits is photolithograph. This method can not have mass production, so this method wastes time and human effort. In this study, all polymer flexible circuits are fabricated using the inkjet process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.189-192
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• 2002

Recently, micro-nano system is fabricated by photolithograph method. This method can not have mass production, so this method wastes time and human effort. accordingly, the aim of this paper is to research on injection molding of micro-nano system. For injection molding process, development of micro-nano mold is required. Mold for injection mold process is maintained its shape in high pressure and temperature. So in this paper, we studied the simulation of mold fur injection molding and then we consider a result of injection molding simulation.

• Journal of KSNVE
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• v.2 no.4
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• pp.281-292
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• 1992

Two types of vibration problems are encountered in industrial field: active isolation and passive isolation. In a passive type of vibration isolation, a foundation of a delicated machinery such as TEM, SEM, inspection- probe test, photolithograph, etc. is designed to have a vibration amplitude lower than an acceptable limit. In an active type, the isolation is focused on the vibration reduction caused by the machine itself(pump, motor, press, compressor, etc.). The foundation for such a machine should be so designed as to reduce the transmitted vibration below the permissible level prescribed. At any case, a transmissibility and stability must to be considered. Since an active isolation type is aimed for a vibration source, it is useful to isolate the transmitted vibrations energy from a major vibration source at the specific location. In this paper, a designed methodology of double anti-vibration system has been examined in order to have low transmissibility and reliable stability. Also experiment of scale model behavior has been conducted. Finally, the experiment output of the transfer function is compared to the analytical data.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.73-73
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• 2003

최근 LCD(liquid crystal display)분야에서 고해상도와 빠른 응답속도를 가지는 다결정 실리콘 박막트랜지스터에 대한 연구를 하고 있다. 그러나, poly-Si은 poly-Sil-xGex에 비해 intrinsic carrier mobility가 낮고 고온의 결정화 공정을 필요로 한다. 따라서, Poly-Si을 대체할 재료로 poly-SiGe에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 전계에 의해 결정화가 가속되고 한쪽 방향으로 결정화를 제어하여 채널내 전자나 정공의 이동도를 향상시 킬 수 있는 새로운 결정화 방법인 전계 유도 방향성 결정화법을 이용하여 Ge 함량에 따른 a-Sil-xGex(0$\leq$x$\leq$0.5)의 결정화 특성을 연구하였다. 대기압 화학 기상 증착법으로 5000$\AA$의 산화막(SiO$_2$)이 증착된 유리 기판상에 플라즈마 화학 기상 증착법을 이용하여 800$\AA$의 비정질 실리콘을 증착한 후 RF magnetron sputtering법을 이용하여 Ge 함량에 따른 Sil-xGex 박막을 1000$\AA$ 증착하였다. Photolithograph방법을 이용하여 금속이 선택적으로 증착될 수 있는 특정 Pattern을 가진 mask를 형성한 후 금속을 DC magnetron sputtering법을 이용하여 상온에서 50$\AA$.을 증착하였다. 이후 시편에 전계를 인가하기 위해 시편의 양단에 전극을 형성한 후 DC Power Supply를 통해 전압을 제어하는 방식으로 전계를 인가하였다. 결정화 속도는 광학현미경을 이용하여 분석하였으며 결정화된 영역의 결정화 정도는 micro-Raman spectroscopy로 분석하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.549-554
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• 2017

In this paper, we studied the design and fabrication of $2{\times}2$ microstrip array antenna at around 5 GHz band.. To improve of frequency properties of antenna, feed microstrip patch antenna was simulated by HFSS(High Frequency Structure Simulator). A $2{\times}2$ array antenna was designed and fabricated by photolithograph on an FR4 substrate (dielectric constant of 4.4 and thickness of 1.6 mm). The fabricated $2{\times}2$ array antenna showed a center frequency, the minimum return loss and bandwidth were 5.3 GHz, -24dB, and 390MHz, respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1003-1008
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• 2017

In this paper, we studied the design and fabrication of double T Structure with CPW antenna at around 5 GHz band.. To improve of frequency properties of antenna, Double T Structure with CPW antenna was simulated by HFSS(: High Frequency Structure Simulator). A double T Structure with CPW antenna was designed and fabricated by photolithograph on an FR4 substrate (dielectric constant of 4.4 and thickness of 1.6 mm). The fabricated A double T Structure with CPW antenna showed a center frequency, the minimum return loss and impedance were 5.29GHz, -34dB, and 390MHz, $49.6{\Omega}$ respectively.

• Current Optics and Photonics
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• v.6 no.4
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• pp.381-391
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• 2022

Two-photon-polymerization additive-manufacturing systems feature high resolution and precision. However, there are few reports on specific methods and possible problems concerning the use of small lasers to independently build such platforms. In this paper, a femtosecond-laser two-photon-polymerization additive-manufacturing system containing an optical unit, control unit, monitoring unit, and testing unit is built using a miniature femtosecond laser, with a detailed building process and corresponding control software that is developed independently. This system has integrated functions of light-spot detection, interface searching, micro-/nanomanufacturing, and performance testing. In addition, possible problems in the processes of platform establishment, resin preparation, and actual polymerization for two-photon-polymerization additive manufacturing are explained specifically, and the causes of these problems analyzed. Moreover, the impacts of different power levels and scanning speeds on the degree of polymerization are compared, and the influence of the magnification of the object lens on the linewidth is analyzed in detail. A qualitative analysis model is established, and the concepts of the threshold broadening and focus narrowing effects are proposed, with their influences and cooperative relation discussed. Besides, a linear structure with micrometer accuracy is manufactured at the millimeter scale.