• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.05a
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• pp.150-155
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• 2006

PZT는 높은 분해능을 구현할 수 있는 구동기이지만 그 구동 범위가 협소하다는 단점이 있다. 최근에는 이러한 단점을 극복하기 위한 여러가지 메커니즘들이 제안되고 있다. 본 논문에서는 PZT를 이용하여 넓은 범위의 높은 분해능을 갖는 회전형 스테이지를 개발하였다. 개발되어진 회전형 스테이지는 빔 형태의 예압구조를 이용하였으며 일정한 마찰력을 구현하기 위하여 알루미나와 오닉스를 사용하였다. 대 변위와 미소변위를 동시에 구동하기 위하여 Dual mode control을 적용하였다. 또한 레이지 간섭계를 이용하여 구동기의 최대속도와 분해능을 측정하였으며 Sinsweep를 이용하여 구동기의 주파수 응답을 구하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.74-79
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• 2011

Alignment systems with multi-axis motions are applied to determine vertical arrangement of multilayer assembly such as LCD, PDP, and MLCC. This study reports the development of XY${\theta}$ alignment stage which is designed as thin-type structure and parallel actuations. The thin-type parallel XY${\theta}$ alignment stage is maintained below $1{\mu}m$ in repeatability error. The squareness and straightness also allow precise motion for the alignment by the developed stage. The measured error is ${\pm}6.25{\mu}m$ in the alignment experiment by the vision system on the parallel XY${\theta}$ alignment stage.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.51-58
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• 2008

This paper presents a new design of the precision stage for the reticle in lithography process and a low hunting control method for the stage. The stage has three axes for X, Y, ${\theta}_z$ those actuated by three voice coil motors individually. The designed reticle stage system has three gap sensors and voice coil motors, and supported by four air bearings and the forward/inverse kinematics of the stage were solved to get an accurate reference position. When a stage is in regulating control mode, there always exist small fluctuations(stage hunting) in the stage movement. Because the low stage hunting characteristic is very important in recent lithography and nano-level applications, a special regulating controller for ultra low hunting is proposed in this paper. Also this research proposed the 2-step transmission system for preventing the noise infection from environmental devices. The experimental results showed the proposed regulating control system reduced hunting noise as 35nm(rms) when a conventional PID generates 77nm(rms) in the same mechanical system. Besides the reticle stage has 100nm linear accuracy and $1{\mu}rad$ rotation accuracy at the control frequency of 8kHz.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1193-1197
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• 2008

Bridge is Most from stay of Gantry structures part. In compliance with oneself weight of the bridge deflecting, this occurs drops the location precision of the work tool. Also accelerative at the time of gives a serious load to Y axial motors which transfer the bridge damages. The motor with high-speed transfer of location control which is accurate makes disrupt. The malleability of the bridge to maintain consequently and necessary to minimize a weight. This paper the structural FEM interpretations of the stone and the aluminum alloy with the material by which will be used in the bridge and static deflected and a candle precise plane X-Y stage optimal design with character the interpretation result.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.6
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• pp.134-142
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• 2008

In this paper, we propose a precise linear motion stage supported by magnetically preloaded air bearings. The eight aerostatic bearings with rectangular carbon porous pads were located only one side of vertical direction under the platen where four bearings are in both sides of horizontal direction as wrap-around-design, and this gives simpler configuration than which constrained by air bearings for all direction. Each of the magnetic actuators has a permanent magnet generating static magnetic flux far required preload and a coil to perturb the magnetic farce resulting adjustment of air- bearing clearance. The characteristics of porous aerostatic bearing are analyzed by numerical analysis, and analytic magnetic circuit model is driven for magnetic actuator to calculate preload and variation of force due to current. A 1-axis linear stage motorized with a coreless linear motor and a linear encoder was designed and built to verify this design concept. The load capacity, stiffness and preload force were examined and compared with analysis. With the active magnetic preloading actuators controlled with DSP board and PWM power amplifiers, the active on-line adjusting tests about the vertical, pitching and rolling motion were performed. It was shown that motion control far three DOF motions were linear and independent after calibration of the control gains.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1394-1397
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• 2005

The object of this study was to design of micro stage, which is one of the equipments embodied in ultra precision positioning mechanism. Design factors for micro stage were decided a roundness of hinge, a thickness of hinge, a thickness of stage, a length of arms and a clearance of division. To obtain the $1^{st}$ natural frequency and equivalent stresses, FEM simulation was performed using the table of orthogonal arrays and Taguchi method was used to determine the optimal design parameters. As results of this study, the size of 1st natural frequency and equivalent stresses on micro stage was influenced significantly by a thickness of hinge and a length of arm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1453-1459
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• 2012

The dual stage manipulator is composed of the voice coil motor (VCM) and piezoelectric ceramics transducer (PZT), which can produce the high precise displacement and express a well dynamic performance. However, inaccurate modeling of the dual stage will exacerbate the positioning accuracy. This paper presents an approach to model the dual stage system by using bond graph theory. And the state space equations can be derived through the bond graph straightforwardly, which can be used in computing simulations. Through designing the compensators for the dual stage system and simulating, the dual stage performs better dynamics characteristic than the single actuator system.

• 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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.342-347
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• 2002

After the industrial revolution in 20 century, the world are preparing for new revolution that is society with knowledge for a basis such as IT(Information Technology), NT(Nano Technology) and BT(Bio Technology). Recently, NT is applied to various fields that are composed of science, industry, media and semiconductor-micro technology. It has need of IT that is ultra-precision positioning technology with strokes of many hundreds mm and maintenance of nm precision in fields of ultra micro process, ultra precision measurement, photo communication part and photo magnetic memory. Performance test of servo control system that is used ultra-precision positioning system with single plane X-Y stage is performed by simulation with Matlab. Analyzed for previous control algorithm and adapted for modern control theory, dual servo algorithm is developed by minimum order observer, and stability and priority on controller are secured. Through the simulation and experiments on ultra precision positioning, stability and priority on ultra-precision positioning system with single plane X-Y stage and control algorithm are secured by using Matlab with Simulink and ControlDesk made in dSPACE

• 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.