• 한국전기전자재료학회논문지
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• 제16권5호
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• pp.385-389
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• 2003

There are four main components of the CMP process: polishing pad, slurry, elastic supporter, and pad conditioner. The polishing pad is an essential component to the reproducibility of polishing uniformity in CMP process. However, the polishing pad in recently using metal CMP raised the several points of high cost caused by the increase of cycle time and the many usage of slurry. It is necessary to develop the novel polishing pad which would lead the cost reduction by the higher pad life-cycle, minimized cycle time and lower slurry usage. The characteristics of polishing pad were studied on the effects of different sets of the Polishing pad, which can be applied to metal chemical mechanical polishing process for global planarization of multilevel interconnection structure. The main purpose of this experiment is cost reduction by the increase of pad life-time, the decrease of cycle time and the lower usage of slurry through the specific hard porous structured pad design. It is confirmed that the novel polishing pad made the slurry usage decrease to 60% as well as the pad life-time increase twice with the 25% improvement of removal rate. The polishing time could be decreased and it also helped the cycle time to diminish. It can be expected that this results will help both the process throughput and the device yield to be improved.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.355-358
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• 2003

This paper presents characteristics of vacuum preloaded porous air bearing. Pressure distribution of a porous pad and vacuum pocket are calculated. And load capacity and stiffness of the bearing are analyzed with various vacuum parameters, that is. clearance height. tube diameter, tube length. pumping speed of vacuum pump, vacuum pocket to porous pad area ratio. From the simulation results, optimum clearance for best performance can be selected adjusting these parameters, especially tube diameter which is the most dominant source.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.231-236
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• 2004

The area of flat glass panel displays such as LCD (Liquid crystal display) and PDP (Plasma display panel) has been increased more than 2 $\times$ 2 m$^2$ for productivity improvement. However, such a large panel area incurs large panel deflection during panel transfer using robots or AGV (Automated guided vehicle) systems. Therefore, electronic industries are making an effort to find an alternative transfer system for the large glass panels with small deflection. The air conveyor with porous pads is one plausible solution, but it becomes expensive because the large porous pads cost much and air consumption increases as the panel area increases. In this work, a simple air slit levitating conveyor was devised to lower the equipment cost and to reduce the air consumption of system. The air flow model between the LCD glass panel and conveyor was constructed and its validity was verified by experiments. To minimize the air consumption, the conveyor dimensions were optimized, and the air consumptions between the air conveyors with the air slit and that with the porous pad were compared.

• 연구논문집
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• 통권34호
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• pp.101-112
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• 2004

In order to analyze the motion errors of the aerostatic stage, it is necessary to consider the influence of the moment variation occurredinside the pads. In this paper, a motion error anaysis method utilizing the transfer functions on the reaction force and moment is proposed, and general characteristics of the transfer functions are discussed. Calculated motion errors by the proposed method show good agreement with the ones calculated by Multi Pad Method, which is considered the entire table as an analysis object. Also, by the introduction of the transfer function of motion errors, which represent the relationship between the spatial frequency components of the rail form error and motion errors, motional characteristics of the porous aerostatic stage can be generalized. In detail, the influence of the spatial frequencies is analyzed quantatively, and the patterns of the insensitive frequencies which almost do not affect the linear motion error or angular motion error according to the rail length ratio and the number of the pad are verified. The relationship between the moment variation occurred inside the pads and the motion errors is also verified together.

• 복식
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• 제66권4호
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• pp.45-60
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• 2016

Elderly women have a high risk of falling down in their daily lives. The purpose of this study is to develop protective pants for elderly women, which will mitigate the impact of falls, and play a major role in reducing injuries. The two types of design were proposed for development of protective pants by selecting pad insertion point and inserting lining for keeping pad in place through the checklist to investigate from the interviews with the medical workers and the investigation of the user requirement. Design A has protective pads in the hip, hip joint, and knee, while design B has protective pads in the hip and hip joint area. For the impact absorbing material, CR (chloroprene rubber) foam was selected for its flexibility, lightness, and impact absorbing capacity, and its pad shapes were designed to produce much flexibility in consideration of the activity and human body fitness of the wearers. Three kinds of pad types, which are the cut type, the porous type, and the honeycomb type, were proposed, and were manufactured to fit into the protective parts according to their design types.

• ETRI Journal
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• 제27권4호
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• pp.433-438
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• 2005

We present a new type of silicon micro-probe card using a three-dimensional probe beam of the cantilever type. It was fabricated using KOH and dry etching, a porous silicon micromachining technique, and an Au electroplating process. The cantilever-type probe beam had a thickness of $5 {\mu}m$, and a width of $50{\mu}$ and a length of $800 {\mu}m$. The probe beam for pad contact was formed by the thermal expansion coefficient difference between the films. The maximum height of the curled probe beam was $170 {\mu}m$, and an annealing process was performed for 20 min at $500^{\circ}C$. The contact resistance of the newly fabricated probe card was less than $2{\Omega}$, and its lifetime was more than 20,000 turns.

• 한국생산제조학회지
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• 제22권4호
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• pp.635-642
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• 2013

We have prepared a DEMO conveyor device for conveying a large 8G class glass sheet using ahorizontal air-cushion system. This device consists of the body frame and the driving frame that are combined to realize a frame for conveying glass without any contact.The driving frame comprises an air flotation table (bed), drive roller supported at both ends, and ASU. Part of the ASU serves to control the airflow as the chamber consists of a porous pad and fan. Fiber filters replace the porous pad and axial fans serve as an air compressor. In addition, to determine the appropriate glass levitation from the air table, this study examined the design specifications of the applied filter (discharge speed of HEPA and ULPA filters, and flow rate) as well as the height of the and the proper supporting roller height (14mm). Then, after adjusting the position of the ASU and the number of ASUs required to configure the UNIT air floating C/V, we analyzed the height and flatness of the glass and derived the appropriate layout (1140-mm distance between ASUs).

• 한국소음진동공학회논문집
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• 제14권11호
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• pp.1153-1160
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• 2004

In contemporary society, vibration and noise in the road nearby buildings have become social problems as vehicles operation has increased. Especially. in the case of the building used to art performance, available suitability of the building is tested by the indoor noise class. Therefore, the Purpose of this paper is the measurement of the structure-borne noise of Seoul Art Center nearby Umyeonsan tunnel and analyzing the effects of countermeasure to it. To measure the effects of countermeasure, not only structure-borne noise is measured, but also the vibration is measured, before and after the construction of Pavement using pad and porous asphalt. Consequently, the sound pressure level in art center 1st floor is reduced after mat pavement method, structure-borne noise that was high In 25Hz wide-band before pavement decreased regardless of experimental vehicle's velocity Using porous asphalt pavement the noise was reduced about 3 dB(A).

• 한국정밀공학회지
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• 제21권7호
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• pp.185-194
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• 2004

In order to analyze the motion errors of the aerostatic stage, it is necessary to consider the influence of the moment variation occurred inside the pads. In this paper, a motion error analysis method utilizing the transfer functions on the reaction force and moment is proposed, and general characteristics of the transfer functions are discussed. Calculated motion errors by the proposed method show good agreement with the ones calculated by Multi fad Method, which is considered the entire table as an analysis object. Also, by the introduction of the transfer function of motion errors, which represent the relationship between the spatial frequency components of the rail form error and motion errors, motional characteristics of the porous aerostatic stage can be generalized. In detail, the influence of the spatial frequencies is analyzed qualitatively, and the patterns of the insensitive frequencies which almost do not affect the linear motion error or angular motion error according to the rail length ratio and the number of the pad are verified. The relationship between the moment variation occurred inside the pads and the motion errors is also verified together.

• 한국산학기술학회논문지
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• 제17권12호
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• pp.34-40
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• 2016

소비자들의 요구 증가로 고급차종에만 적용하던 통풍 시트는 점차 중소형 차종으로 확대 적용되고 있는 추세이다. 팬에서 발생한 유량이 폼 패드, 필터 폼 및 시트 커버 등을 통과하는 과정에서 많은 손실이 발생하기 때문에, 착좌면에 도달하는 유량의 정확한 해석은 쉽지 않다. 또한 유로 형상이 복잡하여 이의 정확한 모델링 없이는 착좌면에 도달하는 정확한 유량의 해석이 힘들다. 본 연구에서는 팬에서 발생한 유동이 통기 매트와 폼 패드를 통과하였을 때의 유량을 해석하였으며, 해석결과와 실험결과를 비교하였다. 해석에서 유동분산판 내부의 돌기 형상을 보다 정확하게 모델링함으로써, 해석결과와 실험결과의 경향을 정확하게 일치시킬 수 있었다. 유량이 통기성 재료인 패드 폼을 통과하는 과정에서 발생한 손실을 실험으로 측정하여 해석결과를 보정함으로써 해석결과와 실험결과를 정확하게 일치시킬 수 있었다. 다음으로 필터 폼과 시트 커버를 통과하여 착좌면에 도달하는 유량을 실험으로 측정하였다. 착좌면에서의 유량이 많지 않아서, 유량 콘을 사용하여 유량을 측정하였다. 팬에서 발생한 유량의 약 35.7%만이 최종적으로 착좌면에 도달하는 것을 확인할 수 있었다.