• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.265-265
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• 2004

최근 IT산업으로 대표되는 광통신 및 광신호 전달에 이용되는 광 반사경 및 렌즈어레이, 광가이드 판넬(BLU, FLU)등 광부품의 수요가 급증하고 있고, 이의 생산을 위한 다양한 제조공정이 연구 개발되고 있다 근년까지 이러한 마이크로 광부품의 제조방법은 포토리소그래피, 에칭기술을 베이스로 한 MEMS 기술, PDMS를 이용한 복재기술에 크게 의존하고 있다. 기계적 가공법으로는 오래전부터 초정밀 경면 선삭이나 연삭에 의한 마이크로 렌즈와 미세 패턴의 금형가공이 이루어져 왔다.(중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.266-269
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• 2002

Research during the past several years has established the effectiveness of acoustic emission (AE)-based sensing methodologies for machine condition analysis and process. AE has been proposed and evaluated for a variety of sensing tasks as well as for use as a technique for quantitative studies of manufacturing process. STD11 has been known as difficult-to-cut materials. For this study, the micro-grooving machine was developed. The experiments were performed using diamond blade and CBN blade f3r machining STD11. Evaluating the machining conditions, frequency spectrum analysis of acoustic emission (AE) signals according to each conditions were applied.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1597-1600
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• 2005

Recently, the trends of TFT-LCD are large scale and thin thickness, so, the demands of Light Guide Panel(LGP) which is able to substitute for prism sheets are appeared. Functions of LGP obtaining polarization of light of the prism sheet as well as the incidence and reflection of light are demanded. This prismless type LGP to complete functions of the existing LGP and polarization at once must be supported by micro machining technology of LGP surface. In this research, we have used the STAMPER method for the mass product and In-Line process, and the optimized conditions are established by analyzing the cutting force and conditions according to the material and processing properties when the prismless type LGP mold is fabricated. Parameters of the cutting condition were the workpiece and cutting depth.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.918-921
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• 2002

Some investigators who have tried to achieve the highly smooth surface finish using electrochemical processes have reported that high current density produced lustrous surfaces while the opposite conditions produced a passive layer and had a tendency to produce a black surface. However, processing at a low current density may produce a non-lustrous surface but the improvement of dimensional accuracy of the surface is significant. The surface with pulse process was a bit more lustrous than with continuous current but the black passive layer still could be found at grooved surface. There are two ways to achieve highly smooth surface finish. One is brushing it with a brush the other is electrochemical machining (ECM) with high current. The former method is the most common polishing practice, but not only may the surface obtained differ from operator to operator, but precision smooth surface on micro grooves are difficult to obtain. The latter one recently has been used to produce a highly smooth surface after EDM process. However, the material removal rate in ECM with high current is relatively high. Hence the original shape of the micro grooves, which was formed by electrochemical micro-machining (EMM) process, may be destroyed. In this study, an electrochemical polishing process using pulse current is adopted as a possible alternative process when micro grooves formed by EMM process should be polished. Mirror-like micro grooves with lustrous and smooth surface can be produced electrochemically with pulse current because the voltage and current used can be lower than the case of continuous current. This study will discuss the accurate control of physical and electrical conditions so as to achieve mirror-like micro grooves with lustrous and smooth surface without destroying the original shape of micro grooves.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1631-1636
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• 2010

In this study, we demonstrate a nano-scale lithograph obtained on localized (100) silicon (p-type) surface using by modified AFM (Atomic force microscope) apparatuses and by adopting controlling methods. AFM-based experimental apparatuses are connected to a customized pulse generator that supplies electricity between the conductive tip and the silicon surface, while maintaining a constant humidity throughout the lithography process. The pulse durations are controlled according to various experimental conditions. The electrochemical reaction induced by the pulses occurs in the gap between the conductive tip and silicon surface and result in the formation of nanoscale oxide particles. Oxide particles with various heights and widths can be created by AFM surface modification; the size of the oxide particle depends on the pulse durations and the applied electrical conditions under a humid environment.