• 한국전기전자재료학회논문지
• /
• 제22권4호
• /
• pp.303-306
• /
• 2009

This paper describes the characteristics of polycrystalline 3C-SiC doubly clamped beam micro resonators. The polycrystalline 3C-SiC doubly clamped beam resonators with $60{\sim}100{\mu}m$ lengths, $10{\mu}m$ width, and $0.4{\mu}m$ thickness were fabricated using a surface micromachining technique. Polycrystalline 3C-SiC micro resonators were actuated by piezoelectric element and their fundamental resonant frequency was measured by a laser vibrometer in vacuum at room temperature. For the $60{\sim}100{\mu}m$ long cantilevers, the fundamental frequency appeared at $373.4{\sim}908.1\;kHz$. The resonant frequencies of doubly clamped beam with lengths were higher than simulated results because of tensile stress. Therefore, polycrystalline 3C-SiC doubly clamped beam micro resonators are suitable for RF MEMS devices and bio/chemical sensor applications.

• 반도체디스플레이기술학회지
• /
• 제8권4호
• /
• pp.43-48
• /
• 2009

The aim of this paper is to describe the development of the electron-beam optic analysis algorithm for simulating the e-beam behavior concerned with electrostatic lenses and their focal properties in the micro-column of the multi-beam lithography system. The electrostatic lens consists of an array of electrodes held at different potentials. The electrostatic lens, the so-called einzel lens, which is composed of three electrodes, is used to focus the electron beam by adjusting the voltages of the electrodes. The optics of an electron beam penetrating a region of an electric field is similar to the situation in light optics. The electron is accelerated or decelerated, and the trajectory depends on the angle of incidence with respect to the equi-potential surfaces of the field. The performance parameters, such as the working distances and the beam diameters are obtained by the computational simulations as a function of the focusing voltages of the einzel lens electrodes. Based on the developed simulation algorithm, the high performance of the micro-column can be achieved through optimized control of the einzel lens.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2011년도 춘계학술대회 논문집
• /
• pp.777-778
• /
• 2011

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2004년도 추계학술발표대회 개요집
• /
• pp.79-81
• /
• 2004

In this study EB(Electron Beam) welder was modified to apply Ef welder to micro-joining for soldering and micro-brazing. The power and beam current of EB welder is 6kW, 100mA(60kV) and the minimum current was 1mA. The minimum current of EB welder was modified to decrease the amount of beam current to 0.0lmA and the monitoring system to observe materials was made up. The system is developed including teaching function for generating patterns. The control system and CAD/CAM software for EB direct writing was developed and the deflection beam was controlled without moving workpieces. the possibility of applying EB welder to micro-joining for soldering and brazing was studied through this experiments.

• 한국정밀공학회지
• /
• 제22권5호
• /
• pp.175-180
• /
• 2005

The application of focused ion beam (FIB) technology in micro/nano machining has become increasingly popular. Its use in micro/nano machining has advantages over contemporary photolithography or other micro/nano machining technologies such as small feature resolution, the ability to process without masks and being accommodating for a variety of materials and geometries. In this research, fabrication of micro plasma electrode was carried out using FIB. The one of problems of FIB-sputtering is the redeposition of material including Ga+ ion source during sputtering process. Therefore the effect of the redeposition was verified by EDX. And the micro plasma electrode of copper was fabricated by FIB.

• KSTLE International Journal
• /
• 제3권1호
• /
• pp.12-16
• /
• 2002

Micro/nano tribological and water wetting characteristics of ion beam treated PTFE (polytetrafluoroethylene) surfaces were experimentally studied. The ion beam treatment was performed with a hollow cathode ion gun at different argon ion dose conditions in a vacuum chamber to modify the topography of PTFE surface. Micro/nano tribological characteristics, water wetting angles and roughness were measured with a micro tribe tester, SPM (scanning probe microscope), contact anglemeter and profilometer, respectively. Results showed that surface roughness increased with the argon ion dose. Water wetting angle of the ion beam treated samples increased with the ion dose, so the surface shows an ultra-hydrophobic nature. Micro-adhesion and micro-friction depend on the wetting characteristics of the PTFE samples. However, nano-tribological characteristics showed different results. The scale effect of surface topography on tribological characteristics was discussed. Also, the water wetting characteristics of modified PTFE samples were discussed in terms of the surface topographic characteristics.

• 한국지능시스템학회논문지
• /
• 제24권4호
• /
• pp.437-442
• /
• 2014

최근에는 크기 및 비용의 관점에서 많은 장점을 갖는 초소형 해양로봇(Micro Marine Robot : MMR)의 개발 및 적용에 대한 요구가 증가하고 있다. 하지만 국내에서는 그 기반이 매우 부족한 상황이다. 다행히도 초소형 수상로봇(Micro Surface Robot : MSR)의 장애물회피와 관련해서는 크기와 성능의 관점에서 최적화되어 4방향 탐지가 가능한 장애물회피소나(Obstacle Avoidance Sonar : OAS)가 개발되었으나, 제한된 빔폭(beam width) 및 탐지거리를 갖는 고정 소나빔의 사용으로 인하여 장애물의 형상에 따라 탐지성능이 저하되는 문제점이 존재했다. 이러한 문제를 해결하기 위하여, 본 논문에서는 평기어(spur gear) 및 서보모터를 활용하여 회전 소나빔을 구현한 MSR의 메커니즘을 제안하였다. 제안된 메커니즘의 검증을 위해 다각 평면 장애물에 대한 MSR의 벽면 추적(wall-tracking) 문제를 고려하였고, 탐지성능 및 구동명령 측면에서 기존의 고정 소나빔 적용 시와 비교 및 분석을 수행하였다. 실험결과는 제안된 메커니즘의 타당성을 보여준다.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2004년도 춘계학술대회 논문집
• /
• pp.166-171
• /
• 2004

In this study, shape optimization of micro-static mixer with a cantilever beam was accomplished for mixing the mixing efficiency by using successive response surface approximations. Variables were chosen as the length of cantilever beam and the angle between horizontal and the cantilever beam. Sequential approximate optimization method was used to deal with both highly nonlinear and non-smooth characteristics of flow field in a micro-static mixer. Shape optimization problem of a micro-static mixer can be divided into a series of simple subproblems. Approximation to solve the subproblems was performed by response surface approximation, which does not require the sensitivity analysis. To verify the reliability of approximated objective function and the accuracy of it, ANOVA analysis and variables selection method were implemented, respectively. It was verified that successive response surface approximation worked very well and the mixing efficiency was improved very much comparing with the initial shape of a micro-static mixer.

• 한국정밀공학회지
• /
• 제24권10호
• /
• pp.109-116
• /
• 2007

Focused ion beams are a potential tool for micro/nano structure fabrication while several problems still have to be overcome. Redeposition of sputtered atoms limits the accurate fabrication of micro/nano structures. The challenge lies in accurately controlling the focused ion beam to fabricate various arbitrary curved shapes. In this paper a basic approach for the focused ion beam induced direct fabricate of fundamental features is presented. This approach is based on the topography simulation which naturally considers the redeposition of sputtered atoms and sputtered yield changes. Fundamental features such as trapezoidal, circular and triangular were fabricated with this approach using single or multiple pass box milling. The beam diameter(FWHM) and maximum current density are 68 nm and $0.8 A/cm^2$, respectively. The experimental investigations show that the fabricated shape is well suited for the pre-designed fundamental features. The characteristics of ion beam induced direct fabrication and shape formation will be discussed.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2003년도 추계학술발표대회 개요집
• /
• pp.24-26
• /
• 2003

In this study EB(Electron Beam) welder was modified to apply EB welder to micro-joining with solder ball and Pt wire. The power and beam current of EB welder is 6kW, 100mA and the minimum current was 1mA. The minimum current of EB welder was modified to decrease the amount of beam current to 0.0lmA and the monitoring system to observe materials was made up. The control system and CAD/CAM software for e-beam direct writing was developed and the deflection beam was controlled without moving workpieces. the possibility of applying EB welder to micro-joining with solder ball and Pt wire was studied through this experiments.