• Optical Science and Technology
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• v.9 no.2
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• pp.22-36
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• 2005

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.81-85
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• 2006

In this study, we have been examined nano Injection Molding process which can improve transcription of 100nm-level pattern. We changed the various parameter (temperature of injection mold, clamp force, temperature of nozzle) which can be influence for improving transcription. And we measured and analyzed shapes of 100nm-level pattern by Automic Force Microscope for proving transcription. We made the Blu-ray Disc sample for proving transcription. And we measured HF-Signal and jitter. As a result, when the temperature of mold is more than $120^{\circ}C$ and the clamp force is more than 10 ton, We reached over 95 percent of transcription compared with stamper pattern. And we reached in-spec. value for HF-Signal and Jitter. Then we reached over 95 percent of transcription compared with stamper pattern.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.346-350
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• 2004

In Blu-ray(BD) optical system, as a short laser wavelength of laser diode and thin cover layer thickness of' disc, the proper adjustment of spherical aberration should be performed. Considering thin cover layer' thickness and tolerance variation of disc in BD optical system, spherical aberration in BD format is mort: serious than CDㆍDVD format Especially, in dual-layer disc, to compensate the aberration at each layer, optical component should be moved finely in the way of optical path. In this study, 1 -axis moving actuator was introduced as the method of compensating the spherical aberration, and the mechanism of the system was described. Finally, its effect on optical system will be mentioned.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.162-167
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• 2006

Hot embossing lithography(HEL) has the production advantage of comparatively few process step, simple operation, a relatively low cost for embossing tools(Si), and high replication accuracy for small features. In this paper, we considered the nano-molding characteristic according to molding parameters(temperature, pressure, times, etc) and induced a optimal molding condition using HEL. High precision nano-patter master with various shapes were designed and manufactured using the DRIE(Deep Reactive ion Etching), LPCVD(Low Pressure Chemical Vapor Deposition) and thermal oxidation process, and we investigated the molding characteristic of DVD and Blu-ray nickel stamp. We induced flow behaviors of polymer, rheology by shapes and sizes of the pattern through various molding experiments. Finally, with achieving nano-structure molding with high aspect ratio, we will secure a basic technology about the molding of large-area nano-pattern media.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.495-498
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• 2009

To improve the efficiency of the high voltage cable for BLU(backlight unit) of TFT-LCD(Thin Film Transistor-Liquid Crystal Display), the analysis for the trial products(UL3239, UL3633) is conducted by using SEM(scanning electron microscope) and EDX(Energy Dispersive X-ray Spectroscopy). The result that it is possible to accumulate the know-how to about stranding pitch through effective improvement of stranding process. The troubles which are the badness of withstanding voltage and tensile strength etc. are solved by development of excellent material. Furthermore, phenomenon of conductor unfasten in the harness work is solved by improvement of the stranding wire process.

• Information and Communications Magazine
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• v.20 no.6
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• pp.778-799
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• 2003

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.93-94
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• 2008

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.722-723
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.161-162
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• 2007

• Journal of the Korean Society for Precision Engineering
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• v.25 no.12
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• pp.132-138
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• 2008

Recently, mastering processes for high density optical disc such as Blu-ray disc rely on electron beams, which are operable in only vacuum. In the mastering process, one of the most important tasks is to design precision stages for providing precise positioning of the works with respect to the source in a high vacuum environment. In this paper, we have developed a precision rotation table usable in the electron beam mastering. The rotation table adopted air bearings for a high positioning repeatability and velocity stability. The air leakage from the air bearings has been minimized by employing the differential exhaust scheme using three steps of air drain. The design parameters such as diameters of exhaust lines, seal lengths, and pumping speeds were decided according to the optimization method using genetic algorithm. The performance on the vacuum level of the rotation table was evaluated experimentally and theoretically. The results indicate that a vacuum level of $10^{-4}$ Pa is achieved with operation of air bearings in a vacuum chamber, which is sufficient for the electron beam mastering.