• 동력기계공학회지
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• 제10권2호
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• pp.99-103
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• 2006

The laser interferometer has been used for measurement of the micro displacement error. Although the laser interferometer is widely accepted as a tool for measurement of motion accuracy, the set-up procedure is time-consuming because of the strict requirement on alignment between a laser head and optic units. This paper addresses the development of a laser interferometer to measure the micro displacement for a micro machine. The portable laser interferometer which integrates a laser probe and optics, is developed for the convenient measurement. For the experiment, moving mirror set up on the micro stage. The velocity decoding board is also added to calculate doppler shift frequency directly. The output signal is obtained and analyzed by LabView. Finally experiments are found out the relation between micro displacement and output signal.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.334-339
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• 2004

Ultraprecision machining and MEMS technology have been taken more and more important position in machining of microparts. Micro endmilling is one of the prominent technology that has wide spectrum of application field ranging from macro parts to micro products. Also, the method of micro-grooving using micro endmilling is used widely owing to many merit, but has problems of precision and quality of products due to tool wear and tool fracture. This investigation deals with state monitoring using acoustic emission(AE) signal in the micro-grooving. Characteristic evaluation of AE raw signal, AE hit and frequency analysis for state monitoring is also presented in the paper.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.500-504
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• 2004

The bio-micro pin has been usually used for the biochemistry analysis. The manufacturing capability of the micro-pin and the their array with the effective and low-cost way is very important and it gives great economical benefits to developers. The micro-pin is composed of the sample channel for holding the liquid with the fixed volume, the flat tip which determines the printing quality and the pin head for preventing the rotation of the pin in the holder. In this study, we have manufactured newly designed micro-pins by the wire-EDM process with special jigs, and analyzed liquid holding and printing characteristics with respect to the variation of the shape and the tip size of the micro-pin.

• 한국공작기계학회논문집
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• 제14권5호
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• pp.13-20
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• 2005

Micro EDM process is generally used for machining microholes, cavities, and three dimensional shapes. For machining micro structures, first of all, micro tool electrode is indispensable and WEDG system is proposed for tool fabrication method. When using WEDG, its machining characteristics are highly affected by many EDM parameters such as applied voltage, current, rotation speed, capacitance, and pulse duration. Therefore, the design of experiment is introduced to fully understand the effect of the EDM parameters on machining tool electrode. And an attempt has been made to develop the mathematical model for predicting the size of the tool electrode by calculating spark distance. The suggested model was verified with experiment and predicted working gap distance is in good accord with the measured value.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.407-412
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• 2005

For micro electrochemical machining (ECM), tool electrodes with various sizes and shapes are necessary. In this paper, tool electrodes were fabricated by micro electrical discharge machining (EDM). Electrode material is tungsten carbide which has high rigidity and good conductivity for micro electrochemical machining. Disk-type and sphere-type electrodes were fabricated to prevent taper shape of side walls or to produce spherical features. Various 3D micro structures were fabricated by electrochemical milling with developed electrodes.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.274-279
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• 2002

In this paper, the development process of an unique and creative micro/nano-structure fabrication technique based on micro/nano-tribology are reviewed and discussed. The so-called Mechano-Chemical Process(MCP), which has been developed since 1995 by Tribology Research Laboratory at Yonsei University with the motivation to overcome the demerits of the conventional photolithographic techniques, is based on the fundamental understanding of the interaction between the tool tip and the workpiece surface. This process is a maskless process which offers tremendous flexibility in surface patterns that can be created on a workpiece surface without using any capital intensive equipment. It Is capable of fabricating the prototypes of micro/nano-components, micro- structured surface with various geometries, micro-molds for making polymer or metal parts, and micro-fluidic channels for lab-on-a- chip

• 한국생산제조학회지
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• 제25권2호
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• pp.143-148
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• 2016

A micro end mill is one of the precise tools used in machining ultra-precision products such as microchannel and micropatterned mold. To achieve the required precision of these products, several studies investigated the cutting force, burr formation, and burr generation mechanism of micro end mills; however, there are few studies on the alignment of micro tools, which is the foundation of machining. Hence, in this investigation, relation expressions were derived to determine the relation between the misalignment parameters and the machining accuracy. At the same time, the effect of the machining parameters was analyzed using a multiple linear regression analysis and the analysis of variance. The results indicate that the tilting angle of a micro tool has more influence on the machining accuracy than other parameters.

• 한국공작기계학회논문집
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• 제16권6호
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• pp.168-174
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• 2007

A ceramic glass mold was developed for micro hot-embossing and replicated polymer parts are fabricated. The glass-ceramic micro mold could be fabricated with a laser process and a wet etching process and the fabrication time could be saved a lot. Various polymer micro structures can be obtained by hot-embossing. The process parameters such as ho-embossing temperatures or pressures were investigated and optimized. This process can be applied for fabrication of micro structures for flip-chips or micro fluidic channels for bio-engineering. The advantages and disadvantages of this process are discussed, too.

• 한국공작기계학회논문집
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• 제17권2호
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• pp.51-57
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• 2008

Recently, the manufacturer of microscopic structures along with the development of technology to produce electronics, communication and semiconductors allows various components to be smaller in size, with higher precision. Therefore, preoccupancy of micro/nano-level machining technology in order to product micro/nano-components and parts is key issue in the field of manufacturing. In this study, machinability of micro machining was studied through the machining of aluminum, brass and steel workpiece. Inspection of the cutting force variation patterns of large numbers of micro machining indicated that characteristics of the workpiece. Surface roughness prediction methods were developed by considering the variation of the static part of the feed direction cutting force. The accuracy of the proposed approaches were tested with experimental data and the agreement between the predictions and actual observations are addressed.

• 한국전기전자재료학회논문지
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• 제31권7호
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• pp.496-501
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• 2018

In this study, we prepared 40, 45, 50, 55, 60, 65, and 70 wt% content composites filled in epoxy matrix for two micro silica and three micro alumina types for use as a GIS heavy electric machine. As a filler type of epoxy composite, micro silica composites showed excellent AC breakdown strength properties compared to micro alumina composites in the case of electrical properties of micro silica and alumina. The electrical breakdown properties of micro silica composites increased with increasing filler content, whereas those of micro alumina decreased with increasing filler content. In the case of mechanical properties, the micro silica composite showed improved tensile strength and flexural strength compared with the micro alumina composite. In addition, mechanical properties such as tensile strength and flexural strength of micro silica and alumina composites decreased with increasing filler content. This is probably because O-H groups are present on the surface of silica in the case of micro silica but are not present on the surface of alumina in the case of micro alumina.