• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.3
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• pp.52-57
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• 2003

In this paper, stability of ultra precision cutting unit is analyzed and this unit is the kernel unit in ultra precision processing machine. According to alteration of shape and material about hinge, stability investigation is performed Through this stability investigation, trial and error is reduced in design and manufacture, at the same time, we are accumulated foundation data for unit control.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2495-2497
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• 2004

A system, featuring the hybrid isolator for control in the vertical direction, of active microvibration control was proposed. The main components of this system are a stage vibration isolation table with built-in acceleration sensors for detecting microvibration, hybrid isolators and a digital controller with high precision signal converters. The vibration control algorithm is focused on settling-time critical application and feedback/feedforward combination.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.198-202
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• 2002

In this paper, stability of ultra precisio unit is analyzed, this unit is the kernel unit precision processing machine. According alteration of shape and material about stability investigation is performed. Through this stability investigation, trial is reduced in design and manufacture, at the time, we are accumulated foundation data for control.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.12a
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• pp.177-181
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• 2003

This paper presents a 3-axis fine positioning stage. All the procedure concerning the design and fabrication of the stage are described. The stage considered here is composed of flexure hinges, piezoelectric actuators and their peripherals. A special flexure hinge is adopted to be able to actuate the single stage in three axes at the same time. A ball contact mechanism is introduced into the piezoelectric actuator to avoid the cross talk among the axes. The final design is obtained with the theoretical analysis on the stage. An actual fine stage is developed and the design specifications are verified through an experiment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.452-460
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• 2002

The precision stage using a novel contact-free planar actuator based on magnetic farces, magnetized force and Lorentz farce, is suggested. In the promising magnetic structure, the mover is driven directly without any transmission mechanism, and doesn't need any auxiliary driver for its posture calibration. Then it is estimated that the proposed operating principle is very suitable for work requiring high accuracy and cleanness, or general-purpose nano-stage. In this paper, we discuss a driving principle of the planar system including the magnetic force generation mechanism, a framework for the force model, governing characteristics of the levitated plate, and a planar motion control of the constructed prototype. And experimental results are given to verify the derived theoretical model and a feasibility of the system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.11
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• pp.1863-1872
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• 2001

In this Paper, we suggest the precision stage using a novel non-contact planar actuator that utilizes an interaction between an array type of air-core solenoids and permanent magnets. The former with axes arranged in the mutually orthogonal direction is fixed on the stator and the latter with the same polar direction is attached below the stage. The promising magnetic structure has little uncertainty such as hysteresis loss caused by ferromagnetic material, then it is simple to quantify the magnetic phenomenon. And all the magnetic forces are transmitted through narrow air-gap between the coil and the permanent magnet, therefore the structure can be highly compacted. Furthermore, the stage or plate can be perfectly isolated from the stator without any wire connection, leading to diminish the generating possibility of wear particles due to mechanical contact. Then. it is estimated that the proposed operating principle is very suitable for work requiring high accuracy and cleanness. or general-purpose nano stage. The main issues rebated to the plate driving are discussed here.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1273-1276
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• 2005

A displacement magnification mechanism is usually employed in a nano-positioning stage to achieve a large stage motion. A lever mechanism is the most widely used displacement magnifying mechanism. For more large stage motion, double or multiple lever mechanisms can be used. In this case, a more accurate analysis model is needed. This study proposes a more reasonable analysis model for a multiple lever mechanism based on the single lever mechanism model. This paper describes that the high equivalent stiffness of the lever is the most important factor reducing the magnification ratio of the lever mechanism through increasing the deflection of the link and including the axial displacement of the pivot.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.912-915
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• 2004

A vacuum environment is very important for NGL(Next Generation Lithography) apparatuses such as EUVL(Extreme Ultra Violet Lithography) or EPL(Electron Projection Lithography) and so on. The performance of these systems is dominated by vacuum level of processing and positioning accuracy of a stage. So, ultra-precision stage usable in a high vacuum level is needed for the improved performance of these devices. In contrast to atmospheric condition, a special attention must be paid to guide bearing, actuator and other elements. In this paper, air bearing is adopted because of its very high motional accuracy. So, air bearing is designed to be vacuum compatible using differential exhaust method, which prevents air from entering into vacuum chamber. For this, leakage analysis is performed theoretically and verified from experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.175-178
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• 2000

An aerostatic stage has frictionless behavior, so it has a advantage of investigation into positioning characteristics. A one-dimensional aemstatic ceramic stage with ballscrew driven and laser scale feedback system is manufactured. aiming at investigating positioning characteristic of aerostatic stage, especially position error and repeatability, we analyze positioning behavior with other factors such as angular error, temperature. Experimemal results show that the aerostatic stage has a l0nm micro step response. Comparing experimental results and calculated abbe's error, we confirm that mean of position error is owing to angular error. And, also we confirm the temperature is dominant factor of repeatability in ten nm order.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.190-194
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• 2001

Because, Piezo-electric transducer(PZT) transform electric energy into mechanical energy, it is a adequate material for positioning control and force control, take excellent properties as actuator with high speed and high performance. Recently, researches of ultra precision positioning using this PZT are advanced in. In this paper, we use a actuator of PZT, design a positioning apparatus with ultra precision position apparatus as hinge structure. Because of this purpose, before, we were confirmed in control properties of ultra precision stage by FEM method.