• Transactions on Electrical and Electronic Materials
• /
• 제6권2호
• /
• pp.39-45
• /
• 2005

Numerical and visualization procedures are used in a finite difference grid to analyze and better understand the heat transfer in the MEMS based air micro-jet array (MIA) impingement cooling device. The Navier-Stokes (NS) equations with incompressible flow are solved using an implicit procedure. The temperature contour and velocity vector visualization diagrams are used for illustration. The computed temperature distribution at the bottom of the MIA is in good agreement with the experimental measurement data. The parameters are investigated to improve the efficiency of heat transfer in the MIA. The optimum configuration of the MIA is suggested. The present modeling explains the flow phenomenon and yields valuable information to understand the flow and heat transfer in MIA.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 추계학술대회논문집
• /
• pp.469-474
• /
• 2005

The most recent trend on digital hearing aid is to increase the ratio of signal to noise by directivity or to develop noise reduction algorithm inside DSP IC chip. This paper designed, fabricated and tested a digital hearing aid directivity testing device in which a micro-mouse-1ike the stepping motor with a speaker rotates around an examinant. Both ears of the examinant were fixed with ITE hearing aids in order to response to receiving sound. The experimental results were compared with a boundary element method program for verification. The diameter of the directivity testing device was 2 [m] and the micro-mouse was precisely controlled by PICBASIC micro processor.

• 한국정밀공학회지
• /
• 제15권12호
• /
• pp.55-61
• /
• 1998

Recently, the needs of machining technologies of very small parts have been increasing with advent of micro-revolution. These technologies have mostly used the method applied to semi-conductor production process such as LIGA, etc. But they have serious difficulties to settle down in terms of workpiece materials, machining thickness, 3-dimensional structure. Therefore. mciro-machining technology using EDM(Electrical Discharge Machining) was proposed. It is very difficult to machine the micro-parts (microshaft, microhole) using conventional machining. Micro-machining using BDM can machine the micro-parts easily because it requires little machining force. This MEDM(Micro-EDM) need the capabilities to move a electrode and control a discharge energy precisely, and the gap control strategy to maintain the optimal discharge condition is necessary. Therefore, in this study, the new EDM machine with high precision motion stage and high-performance EDM device was developed. Using this MEDM machine, we have machined microshaft and microhole with various shapes and sizes.

• 한국추진공학회지
• /
• 제12권1호
• /
• pp.64-70
• /
• 2008

마이크로 가공기술의 눈부신 발달에 힘입어 다양한 항공우주 시스템을 초소형화 하려는 시도가 있어 왔다. 마이크로 비행체, 나노 위성, 마이크로 로봇 등의 개념들이 등장하였다. 이들 독립 이동식 마이크로 시스템을 구동하는 데에는 기존의 배터리 보다 훨씬 에너지 밀도가 높은 동력원이 필요하다. 그러나 이와 같은 고에너지 동력원이 아직 존재하지 않는다. 이 논문에서는 초소형 동력원 연구의 과거와 현재를 살펴보고, 미래 발전 방향에 대한 제안을 시도하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 하계학술대회 논문집
• /
• pp.569-572
• /
• 2000

This paper presents the optimized fabrication and thermal characteristics of micro-heaters for thermal MEMS applications using a SDB SOI substrate. The micro-heater is based on a thermal measurement principle and contains for thermal isolation regions a 10$\mu\textrm{m}$ thick silicon membrane with oxide-filled trenches in the SOI membrane rim. The micro-heater was fabricated with Pt-RTD(Resistance Thermometer Device)on the same substrate by using MgO as medium layer. The thermal characteristics of the micro-heater with the SOI membrane is 280$^{\circ}C$ at input Power 0.9 W; for the SOI membrane with 10 trenches, it is 580$^{\circ}C$ due to reduction of the external thermal loss. Therefore, the micro-heater with trenches in SOI membrane rim provides a powerful and versatile alternative technology for improving the performance of micro thermal sensors and actuators.

• 대한기계학회논문집A
• /
• 제31권12호
• /
• pp.1139-1143
• /
• 2007

A simple method for the fabrication of 3D micro-nano hybrid patterns was presented. In conventional fabrication methods of the micro-nano hybrid patterns, micro-patterns were firstly fabricated and then nano-patterns were formatted on the micro-patterns. Moreover, these micro-nano hybrid patterns could be fabricated on the flat substrate. In this paper, we suggested the fabrication method of 3D micro-nano hybrid patterns using micro-indentation on the anodized aluminum substrate. Since diameter of the hemispherical nano-pattern can be controlled by electrolyte and applied voltage in the anodizing process, we can easily fabricated nano-patterns of diameter of loom to 300nm. Nano-patterns were firstly formatted on the aluminum substrate, and then micro-patterns were fabricated by deforming the nano-patterned aluminum substrate. Hemispherical nano-patterns of diameter of 150nm were fabricated by anodizing process, and then micro-pyramid patterns of the side-length of $50{\mu}m$ were formatted on the nano-patterns using micro-indentation. Finally we successfully replicated 3D micro-nano hybrid patterns by hot-embossing process. 3D micro-nano hybrid patterns can be applied to nano-photonic device and nano-biochip application.

• 대한기계학회논문집A
• /
• 제27권1호
• /
• pp.183-193
• /
• 2003

Micro-weighing device by using null balance method is being essential part in fields of high-technology industries such as precision semiconductor industry, precision chemistry, biotechnology and genetics etc. Also, requirements for high resolution and for large measurement range increase more and more. The performance of the micro-weighing device can be determined by the mechanism design and analysis. The analytical design method has been proposed for the performance improvement such as resolution, measurement range and fast response. The 2-stage displacement amplification is designed to overcome the limit of conventional force transmitting lever. The parallel spring is designed for the measurement result independent of the input force position variation. Also, the natural frequency of mechanism is analyzed for the fast response. After each analysis, optimal design has been carried out. To verify the analysis and design result, characteristics experiments had been carried out after construction. Finally, the system had been controlled.

• Tribology and Lubricants
• /
• 제25권3호
• /
• pp.163-170
• /
• 2009

We developed a compact micro indentation testing device (designated SNUT) which is capable to measure Young's modulus of a sample using depth and applied load data during indentation. Performance of this device was evaluated using pure Ti, pure Ni, and die steel (SKD11). As a result of analysing the indentation test data, the frame compliance $C_f$ was found to influence mainly the modulus by 80% among several factors affecting accuracy of Young's modulus. Project area, which was determined by indirect indentation method, was modified using direct SEM observation. Finally, Young's modulus error was reduced to 5% after taking into consideration the frame compliance and modified projected area from 80% error without any these two correction factors. The performance of SNUT and MTS instruments was compared using same specimen (pure Ti).

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
• /
• pp.1992-1994
• /
• 2005

In this study, Bragg reflector was formed as tungsten(W) and $SiO_2$ deposited by RF magnetron sputtering according to variable conditions of RF power and working pressure to apply to the SMR type FBAR device, one of the next generation mobile communication devices. The micro-structural properties such as a crystal orientation, roughness and micro- structure were measured by XRD, AFM and SEM and the best condition of Bragg reflector was elicited with analyzing that results of the thin films about each conditions. Finally, FBAR device was fabricated with applying the Bragg reflector was formed on the best condition and measured the resonance properties and compared other research and considered it.

• 한국전기전자재료학회논문지
• /
• 제27권10호
• /
• pp.623-629
• /
• 2014

For the semiconductor device safety from over current in the digital electronic circuit system must be surely designed that it's surface mount type micro fuse device. In this paper, We has analysed to the fusing character of micro fuse as a function changed thickness of thermosetting ink epoxy. To the change of thermosetting ink epoxy thickness with in production lot, in the electrically character (fusing test in the 2 multiple over current and 10 multiple over current, surface temperature test in the 1.25 multiple over current) of micro fuse has been tested. According to the electrically character result, changed thickness of thermosetting ink epoxy in designed micro fuse withheld direct effect in both end resistance changes. Also, because high thermal energy in the micro fuse test of over current was occurred to effect such as thermal runaway and explosion. Therefore, screen printing process in the design of micro fuse using thermosetting ink epoxy is very important for production quality improvement.