• 한국공작기계학회논문집
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• 제17권4호
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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.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.465-468
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• 2001

An aerostatic stage has frictionless behavior, so it has a advantage of investigation into positioning characteristics. A one-dimensional aerostatic ceramic stage with ballscrew driven and laser scale feedback system is manufactured, aiming at investigating positioning characteristic of ultra-precision stage. We confirm, this ceramic aerostatic stage has a 10nm micro resolution, and can be reduced mean of position error by compensation of numeric control command. By means of analyzing relationship of position error and change of temperature, we build a on-line compensation algorithm of position error from the measured temperature data. So we can improve repeatability of ultra-precision stage up to 34%($0.095{\mu}$) of the normal condition.

• 기계와재료
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• 제22권1호
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• pp.30-35
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• 2010

전자부품산업이 빠르게 발전하고 있기 때문에 고기능성 PCB의 수요 또한 많이 늘고 있다. 이러한 PCB는 전자제품의 굴곡성(flexibility) 있는 형태로 발전하여 전자제품의 소형화 및 고밀도화가 가능하고, 반복적인 굴곡에 높은 내구성을 갖는 연성(flexible) PCB(FPCB)의 사용이 증가하고 있으며, 이런 시장의 요구에 맞춰 연성 다층 구조의 FPCB에 대한 정밀 고속 가공 기술에 대한 수요도 급격히 확대되고 있다. 따라서 장비 운영의 효율성 극대화 및 설비 투자를 최소화하고 단일 장비로 절단(half cut, full cut), 제거, 트리밍, 리페어 고정 등을 수행할 수 있는 장비 개발을 위한 스캐너/스테이지 고정밀 제어, Z축 스텝가공, 멀티포인트 비전 인식을 통한 왜곡 최소화 등의 요소기술 개발관련 내용을 소개하고자 한다.

• 한국산학기술학회논문지
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• 제13권4호
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• pp.1453-1459
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• 2012

본 연구에서는 보이스코일 모터와 압전 구동기를 동일 축으로 배치함으로써 초정밀 위치결정뿐만 아니라 동특성을 개선할 수 있도록 하는 듀얼 스테이지를 다룬다. 듀얼 스테이지는 모델링이 엉성할 경우 오히려 나쁜 동특성을 보이는 단점이 있다. 이 논문은 본드그래프를 이용하여 듀얼 스테이지를 모델링하고 동적 상태방정식을 본드그래프에서 유도하였다. 또한 동특성을 향상시키기 위한 보상기의 설계 예시를 보이고 있으며, 시뮬레이션을 통해 검증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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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

• 한국정밀공학회지
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• 제33권7호
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• pp.579-586
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• 2016

This paper describes kinematic analysis of a 6-degrees-of-freedom (DOF) ultra-precision positioning stage based on a flexure hinge. The stage is designed for processes which require ultra-precision and high load capacities, e.g. wafer-level precision bonding/assembly. During the initial design process, inverse and forward kinematic analyses were performed to actuate the precision positioning stage and to calculate workspace. A two-step procedure was used for inverse kinematic analysis. The first step involved calculating the amount of actuation of the horizontal actuation units. The second step involved calculating the amount of actuation of the vertical actuation unit, given the the results of the first step, by including a lever hinge mechanism adopted for motion amplification. Forward kinematic analysis was performed by defining six distance relationships between hinge positions for in-plane and out-of-plane motion. Finally, the result of a circular path actuation test with respect to the x-y, y-z, and x-z planes is presented.

• 한국기계가공학회지
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• 제5권1호
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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.

• 한국기계가공학회지
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• 제11권2호
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• pp.112-117
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• 2012

This paper presents a new stopper mechanism for precision stage by using the Piezoelectric element actuator. The new stage including a new stopper mechanism has the precision positioning mechanism that was been developed for generation displacements with nanometer accuracy and a millimeter dynamic range simulataneouly. The stage is composed not of the mechanical two stopper but of only one Piezoelectric element actuator. The characteristics for the new stage and the stopper have been evaluated experimentally. As the results, we can know that the linearity error characteristics of stage is 30nm in the $20{\mu}m$ measurement range. In addition, the experimental results are confirmed the possibility of the movement in millimeter range.

• 한국정밀공학회지
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• 제31권5호
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• pp.423-430
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• 2014

In this study, the five-DOF motion at ultra-precision linear stage under static and dynamic conditions are evaluated through the extending application of ISO 230-2. As the performance factors, the bi-directional accuracy and repeatability of the five-DOF motion are quantitatively evaluated with the measurement uncertainties which are determined using the standard uncertainty of equipment used in experiment. The motion under static condition are analyzed using geometric errors. The five geometric errors except the linear displacement error are measured using optimal measurement system which is designed to enhance the standard uncertainty of geometric errors. In addition, the motion under dynamic conditions are analyzed with respect to the conditions with different feed rate of the stage. The experimental results shows that the feed rate of stage has a significant effect on straightness motions.

• 한국정밀공학회지
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• 제25권6호
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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.