• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2011년도 춘계학술대회 논문집
• /
• pp.447-452
• /
• 2011

This paper predicted the dynamic behaviors of a cantilevered carbon nanotube(CNT) incorporating the electrostatic force, van der Waals interactions between the CNT and ground plane. The structural model of the CNT includes geometric and inertial nonlinearities for predicting various phenomena of nonlinear responses of the CNT due to the electrostatic force. In order to solve the problem, we used Galerkin's approximation and the numerical integration techniques and as a result, we predicted characteristics of nonlinear response of nano resonator. The cantilevered CNT shows complex dynamic responses and instabilities due to the applied ac and ac voltages, and driving frequencies. The results investigated in this paper are helpful to the modeling of nanotube based electromechanical devices such as nano-resonators and nano-sensors.

• 전기학회논문지
• /
• 제58권10호
• /
• pp.1936-1941
• /
• 2009

This paper deals with a new methodology for topology optimization in which the topology of the design domain may change during the shape optimization process. To achieve this, the concept of the topological gradient is introduced to compute the sensitivity of an objective function when a small hole is drilled in the domain. Based on shape and topological sensitivity values, the shape and topology of the design domain may be simultaneously changed during design iterations if necessary. To verify the advantages and also to facilitate understanding of the method itself, two electrostatic design problems have been tested by using 2D finite element analysis: the first is the inverse problem of a simple dielectric model and the second is the rotor design of a MEMS actuator.

• 한국안전학회지
• /
• 제21권4호
• /
• pp.60-65
• /
• 2006

It is a well known fact that LCD is a central part of the IT industry which is important in the present and the future. But the biggest problem of LCD manufacturing is maintaining a cleaning room environment and administration. Therefore the purpose of this study is to first, prevent the yield depreciation and damage of products, and second, protect the worker ftom accidental electrostatic discharge during LCD manufacture. The soft x-ray ionizer is a type of electrostatic reducer device. It protects against electrostatic discharge in the cleaning room environment and is a necessary environmental factor during LCD production. The positive aspects of the soft x-ray are its shorter time and wider angle of exposure. But the negative aspect of the soft x-ray is its need for several shielding of protection from the harmful x-ray exposure. On this study, the development of the Air Nozzle-type ionizer to amend and refine some problems. For example, examined the electrostatic reduce device of a soft x-ray type and discovered the ion did not go inside well. also workers to be free from danger. An Air Nozzle-type ionizer is comprised of soft x-ray radiation and ionized air production. Air is injected through the nozzle after being ionized from radiation. It supplies air keeping the same pressure into the end foundation of ion production. The soft x-ray is the structure which radiates ionized air through the nozzle (21 holes) having micro holes of the ionizable radiation after ionizing the inside air by the ion production. A worker does not need a cover to protect against x-rays and the Air Nozzle-type ionizer is easy to set up and is more effective at eliminating electrostatic.

• 한국정밀공학회지
• /
• 제30권6호
• /
• pp.567-572
• /
• 2013

In many electro-devices, the vacuum process is used as the manufacturing process. However, the vacuum process has a problem, it is difficult to apply to a continuous process such as a R2R(roll to roll) printing process. In this paper, we propose an ESD (electro static deposition) printing process has been used to apply an organic solar cell of thin film forming. ESD is a method of liquid atomization by electrical forces, an electrostatic atomizer sprays micro-drops from the solution injected into the capillary with electrostatic force generated by electric potential of about several tens kV. The organic solar cell based on a P3HT/PCBM active layer and a PEDOT:PSS electron blocking layer prepared from ESD method shows solar-to-electrical conversion efficiency of 1.42% at AM 1.5G 1sun light illumination, while 1.86% efficiency is observed when the ESD deposition of P3HT/PCBM is performed on a spin-coated PEDOT:PSS layer.

• 한국안전학회지
• /
• 제17권4호
• /
• pp.94-100
• /
• 2002

As the use of automatic handling equipment for sensitive semiconductor devices is rapidly increased, manufacturers of electronic components and equipments need to be more alert to the problem of electrostatic discharges(ESD). In order to analyze damage characteristics of semiconductor device damaged by ESD, this study adopts a new charged-device model(CDM), field-induced charged model(FCDM) simulator that is suitable for rapid, routine testing of semiconductor devices and provides a fast and inexpensive test that faithfully represents ESD hazards in plants. High voltage applied to the device under test is raised by the field of non-contacting electrodes in the FCDM simulator, which avoids premature device stressing and permits a faster test cycle. Discharge current and time are measured and calculated. The characteristics of electrostatic attenuation of domestic semiconductor devices are investigated to evaluate the ESD phenomena in the semiconductors. Also, the field charging mechanism, the device thresholds and failure modes are investigated and analyzed. The damaged devices obtained in the simulator are analyzed and evaluated by SEM. The results obtained in this paper can be used to prevent semiconductor devices form ESD hazards and be a foundation of research area and industry relevant to ESD phenomena.

• 한국위성정보통신학회논문지
• /
• 제8권4호
• /
• pp.124-129
• /
• 2013

PPS 구조가 삽입된 N형 실리콘 제어 정류기 소자를 마이크로 칩의 고전압 I/O 응용을 위해 연구하였다. 종래의 NSCR_PPS_Std 표준소자는 매우 낮은 스냅백 홀딩 전압을 갖는 전형적인 SCR 특성을 가지고 있어 정상적인 동작 동안 래치업 문제가 나타나는 것으로 보고되고 있다. 그러나 본 연구에서 제안하는 CPS 및 부분적으로 형성된 P-Well(PPW) 구조를 갖는 변형된 NSCR_PPS_CPS_PPW 소자는 높은 래치업 면역과 트리거링 전압의 조절이 용이한 안정한 ESD 보호 성능을 나타내어 고전압 동작용 마이크로 칩의 정전기보호 소자로 적용 가능함을 확인하였다.

• 대한기계학회논문집A
• /
• 제25권11호
• /
• pp.1796-1801
• /
• 2001

For micro-machines, very few design methodologies based on optimization hale been developed so far. To overcome the difficulties of design optimization of micro-machines, the search method for multi-dimensional design window (DW)s is proposed. The proposed method is defined as areas of satisfactory design solutions in a design parameter space, using both continuous evolutionary algorithms (CEA) and the modified K-means clustering algorithm . To demonstrate practical performance of the proposed method, it was applied to an optimal shape design of micro electrostatic actuator of optical memory. The shape design problem has 5 design parameters and 5 objective functions, and finally shows 4 specific design shapes and design characters based on the proposed DWs.

• 한국위성정보통신학회논문지
• /
• 제8권1호
• /
• pp.45-53
• /
• 2013

기존의 NEDSCR 소자는 매우 낮은 스냅백 홀딩전압과 낮은 온-저항을 가져 정상적인 동작 동안 래치업을 초래하므로 ESD 보호소자로 사용하는데 어려움이 있었다. 본 연구에서는 NEDSCR 소자의 시뮬레이션 및 TLP 테스트를 통해 이러한 단점들을 극복할 수 있는 새로운 방법을 제안하였다. 매우 우수한 ESD 보호 성능과 높은 래치업 면역 특성을 구현하기 위해 N+ 소오스 확산영역을 둘러싸는 P형의 CPS 이온주입공정을 추가함으로써 NEDSCR 소자의 스냅백 홀딩전압과 온 저항을 증가시켜 정전기 보호 성능을 개선시킬 수 있는 것으로 입증되었다.

• 한국가스학회지
• /
• 제4권4호
• /
• pp.20-24
• /
• 2000

한국의 Liquid Petroleum Gas 충전소에 있어서 안전관리자의 정전기에 대한 안전 의식을 설문 조사했다. 또한, 위험요소로 판단된 일반 작업복과 순면 작업복의 정전기에 의한 화재 폭발 위험성을 평가했다. 설문 조사에 의하면, 충전소에서는 정전기 예방 측면의 효율적인 교육 및 인식 부족으로 인해 무분별한 작업복을 착용하고 있는 것으로 나타났다. 특히 현재 착용하고 있는 일반 작업복의 경우, 실험에 의한 대전 전하량이 동복 1.79$\mu$C 춘추복 1.44$\mu$C, 하복 1.02$\mu$C로 한국공업규격 (KS K-7807) 에서 정전기 재해 위험 가능성에 대해 언급한 0.60$\mu$C를 크게 상회하여 위험성이 존재했다. 반면. 순면 작업복의 경우는 대전량이 0.52$\mu$C에서 0.42$\mu$C의 범위로 안전한 것으로 나타났다. 따라서, 향후 시각적, 체험적 교육을 병행한 정전기 교육의 질적 향상이 요구되며, 정전기에 의한 재해를 방지하기 위해 착용하는 작업복에 대한 관련 기술 기준의 제정이 요구된다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제48권6호
• /
• pp.469-474
• /
• 1999

Methods and systems to remove static electricity are requested in the field of industry because the static electricity causes a flammable gas explosion or fire and a reduction of production rate in manufacturing semiconductor devices and so on. This paper is a basic study about a new structure of electrode system to control the quantities of generated ions and to solve the problem of dust attachment to needle electrode. In addition, a new type field controlled electrostatic charge neutralizer was proposed, and it could control the electric field in the end of the needle electrode by controlling the voltage of the third electrode around the tip of the needle electrode. As aresult, it was possible to control the quantities of generated ion by controlling the electric field in the needle electrode with the third electrode, which shows the possibilities to solve the nonequilibrium of generated ions in ac power source and the problem of the dust in the needle electrode.