• Journal of the Korean Society for Precision Engineering
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• v.33 no.11
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• pp.885-891
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• 2016

3D images are generally manufactured by complex production processes. We suggested a simple method to make 3D images based on a mechanical machining technology in this study. We designed a tetrahedron consisted of many arcs having the depth of $100{\mu}m$ and the pitch of $500{\mu}m$, and machined them on an aluminum plate using end-milling under several conditions of feed-rate and depth of cut. The area of undeformed chip including depth of cut and feed-rate can predict quality of the machined arcs more precisely than the undeformed chip thickness including only feed rate. Moreover, a diamond tool can improve the quality than a CBN tool when many arcs are machined. Based on the analysis, the designed tetrahedron having many arcs was machined with no burr, and it showed different images when observed from the left and right directions. Therefore, it is verified that a 3D image can be designed and manufactured on a metal plate by end-milling under optimized machining conditions.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.345-348
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• 2008

Metallic bipolar plate for molten carbonate fuel cell(MCFC) is composed of the shielded slot plate and the center plate. Among these, the center plate plays an important role in gas sealing. Therefore, manufacturing of the center plate is considered one of the key issues in MCFC. The center plate is manufactured by bending process. In bending process, springback and recoiling are two main problems. The aim of this article is to optimize the bending process of the center plate regardless of springback and recoiling. To achieve this goal, we proposed the punch having step to reduce springback and recoiling. Using finite element method and $L_9$ orthogonal array, we determined the main factors in the center plate bending process. And we found the optimal bending process condition for the MCFC center plate.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.1
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• pp.39-44
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• 2006

Ultra precision positioning mechanism has been widely used on semiconductor manufacturing equipments, optical spectrum analyzers and cell manipulations. Ultra precision positioning mechanism consists of several actuators, sensors, guides and control systems. Its efficiency depends on each performance of components. The object of this study is to design and analyze the micro stage that is one of the equipments embodied in ultra precision positioning mechanism. The micro stage consists of PZT actuators and flexure hinges. The structural design of flexure hinge is optimized by using RSM and FEM. The control factors concerned with the design of flexure hinges of stage and arms are optimized by minimizing the equivalent stress on the hinge and maximizing 1st natural frequency based on RSM and FEM simulation under various kinds of design conditions.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.204-204
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• 2012

고용량/대면적/초정밀 제품을 지향하는 개발추세에 따라 고진공 펌프중 하나인 크라이오펌프의 활용도가 크게 증가하며 첨단 공정장비인 LCD 분야 등과 같이 수소 분자와 물 분자 등의 배기가 중요한 응용분야에 크라이오펌프의 수요가 대부분을 차지하고 있다. 그러나 크라이오펌프의 운전성능에 대한 표준절차에 따른 실질적인 측정은 빈약한 편이다. 이에 크라이오펌프의 종합 성능평가 기술 개발을 통해 실질적인 크라이오펌프의 운전성능을 제시하고자 한다. 본 연구에서는 고진공 펌프중의 하나인 크라이오펌프의 종합 성능평가 표준절차 및 표준시스템에 대해 소개하며, 상용화 제품에 대한 각 회사에서 제시하고 있는 성능지표에 대해 실질적인 측정에 대한 비교분석을 하고자 한다. 또한 가장 중용한 성능지표 중의 하나인 배기속도 측정에 대해 물리적 특징과 구조적 오차에 대한 보정 식들을 제공하고자 한다.

• Electronics and Telecommunications Trends
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• v.28 no.2
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• pp.77-85
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• 2013

본고에서는 의료용, 보안용, 정밀거리 측위 등 다양한 분야에 응용이 가능한 근거리 고해상도 레이더 칩 기술에 대하여 소개한다. 먼저 근거리 고해상도 레이더 칩의 대표적인 구조와 동작원리에 대하여 기술하고 상용제품, 최신 논문에서 발표된 레이더 칩에 대하여 소개하였다. 고해상도를 얻기 위한 짧은 펄스 폭(나노초, 십억분의 1초)을 가지는 펄스를 송신하고 목표물을 맞고 되돌아온 에코 펄스를 고해상도로 수신하여 복원된 펄스로부터 얻어지는 거리정보로부터 신호처리 과정을 거쳐 고도화된 응용 분야에 따른 부가적인 정보를 얻는다. 수신기는 상관(correlation)법에 의한 수신 방식과 샘플링(sampling)에 의한 수신 방식으로 크게 나눌 수 있다. 끝으로 한국전자통신연구원에서 개발 중인 CMOS(Complementary Metal Oxide Semiconductor) 기술을 이용한 근거리 레이더 칩의 목표 성능, 구조, 설계 및 측정 결과에 대하여 소개하였다.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.39-41
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• 2003

This paper deals with the characteristics of the permanent magnet type linear synchronous motors(PMLSMs). Firstly, the structures and the characteristics of a slotted type and a slotless type PMLSM are compared. Secondly, the analyses and the design methods of each motor are presented. Finally, slotted type PMLSM and slotless type PMLSM are designed using the presented design method.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.227-228
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• 2003

대기 중에 존재하는 휘발성 유기화합물 (Volatile Organic Compound: VOC)의 경우 반응성이 매우 높고, 잔존농도가 여타 가스상 오염물질에 비해 상대적으로 낮기 때문에, 채취와 분석에는 전문적인 기술이 요구된다 (Hidy, 2000; Yamamoto et al., 2000). 많은 연구자들이 VOC 성분의 분석에 연계된 실험적인 오차를 줄이기 위해 많은 노력을 기울여왔다. 실제로 다양한 채취 및 분석방식을 사용하는 개별 연구기관들 간에 동시비교실험을 수행한 결과, 각 연구기관들 간에 대체로 유사한 분석결과를 산출하는 것이 가능하다는 점도 이미 확인된 바 있다(나광삼 등, 1998; 김기현 등, 2000; Barket Jr. et al., 2001). (중략)

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.422-428
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• 2002

In this study, actuator, sensor, guide, power transmission element and control method are considered for ultra-precision positioning apparatus. Through previous process, single plane X-Y stage with ultra-precision positioning is manufactured. Global stage for the purpose of materialization with robust system, is combined by using AC servo motor and ball screw and rolling guide. And ultra-precision positioning system is developed by micro stage with elastic hinge type and piezo element. global servo and micro servo for the purpose of materialization positioning accuracy with nm(nanometer) are controlled simultaneously by using incremental encoder and laser interferometer as displacement measurement sensor. Through previous process, ultra-precision positioning system (100mm stroke and ${\pm}$ 10nm positioning accuracy) with single plane X-Y stage are materialized.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.524-529
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• 2004

Recently High precision positioning device is used in many kinds of manufacturing and scientific instruments. Piezoelectric transducer is applied to the positioning devive as actuator, PZT has a high resolution, however, moving range is short. Many researcher have developed the mechanism for increasing a motion range. The types of increasing motion range mechanism with PZT are inertial slider, friction driver, ultrasonic motor, etc. In this paper we discuss the review of the hish precision actuator mechanism with PZT. Many kinds of mechanism for high precision are shown and compared.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.453-458
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• 2004

A capacitate sensor is a proper device for measuring high small displacement. General design parameters and procedure are discussed and a test sensor was built to have a measuring range of 100$\mu\textrm{m}$ and a sensitivity about 30nm. This sensor has too opposing electrode of comparably large area and has nominal gap distance about 150$\mu\textrm{m}$. So as to achieve a nano order displacement sensitivity, both sensor and target system have to be considered. This is important for the sensitivity can be achieved by minimizing a system total noise level in electronic type sensor application. Typical performance of the developed sensor is demonstrated in precision moving stage having 0.1$\mu\textrm{m}$ moving resolution.