• Proceedings of the KSME Conference
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• 2001.11a
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• pp.871-875
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• 2001

Laser photolithography technique is useful for fabricating micro-patterns of silicon wafers. In this work, the laser photolithography micromachining technique is optimized based on Taguchi method. Sensitivity analysis was performed using laser scanning speed and laser power level as the parameters. The results show that for the photoresist used in this work, a laser scan speed of $70{\mu}m/s$ at 50mW laser power gives the best result.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.199-202
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• 1999

In this paper, a possibility of building various types of RF passive components using the silicon micromachining technique has been examined with special emphasis on the wireless and mobile communication applications. Silicon micromachining technique is compatible with conventional silicon IC process and could provide a possibility of integrating base-band signal processing units and RF passive and active circuit components all in one silicon wafer rendering implementation of system-on-chip paradigm for future mobile and wireless communication systems.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.322-323
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• 2003

Silicon substrate was fabricated by bulk silicon micromachining and it's structure is based on a proof mass suspended by two beam. To monitor the acceleration, dynamic excitation of accelerometer was performed using a shaker. The attached FFPI and suspension beam are bent because support beam move with variation of the proof mass. Thus phase difference detected by the acceleration change. So we can know that resonance frequency of fabricated accelerometer is about 557 Hz and dynamic range was measured from 0 g to 2 g.

• Journal of the KSME
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• v.33 no.6
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• pp.523-528
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• 1993

과거 10년 동안 마이크로 전자 공학의 극소형화는 실리콘 기판상에서 평면구조를 제작하는 기 술의 발전을 가져왔으며 정보처리 분야에 일대 혁명을 가져왔다. 그런데 지금은 이 기술의 발 전으로 기계공학에서도 이에 상응하는 연구개발이 진행되고 있으니 이를 총칭하여 마이크로 가 공기술(micromachining)이라 부른다. 기계, 광학, 전자 부품의 마이크로 집적화는 하나의 마이 크로 시스템으로 구현되어 기술혁신의 새로운 영역을 개척할 것으로 예상되고 있다. 이 새로운 기술은 마이크론 단위의3차원 초정밀 가공을 가능케 함으로써 미래 메카트로닉스 (mechatronics)의 새로운 영역으로 자리잡게 될 것으로 전망한다. 이 글에서는 마이크로 시스템에 대해서 기술하고자 한다.

• Journal of the KSME
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• v.33 no.6
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• pp.499-514
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• 1993

이 MEMS연구는 상당히 넓은 분야를 포함하나, 그 핵심은 바로 마이크로가공 기 술(micromachining technology)에 있다. (막연히 작은 것이 아닌 마이크로미터 단위의 가공이라는 점을 살리기 위해, "마이크로" 가공이라 부르겠다.) 이 글에서는 우선 MEMS란 무엇인가에 대해 언급한 후, MEMS에 있어서의 마이크로가공(micromachining)이 어떤 것인지를 소개, 설명함에 주력한다. 마이크로가공 기본개념의 전달에 있어서는, 처음 대하는 이들의 이해를 돕기위해 되 도록 인용을 줄이고 핵심개념만 담아 최대한 단순화시켜 설명하였다. 이러한 핵심 개념을 바탕 으로하여 설명되는, 뒤 따르는 실제 예로는 기계공학적으로 관련이 있어 보이는 몇 가지를 인 용하였다.지를 인 용하였다.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.413-415
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• 1996

This paper presents a technique for fabricating an electro-optical microlens for microcolumn e-beam system. The device, named Self-Aligned Microlens (SAM) was realized by mixing surface and bulk micromachining technology. The microbridges were formed on both sides of silicon wafer symmetrically. The alignment error between the electrodes could be controlled within a few micrometers with also reducing the numbers of anodic bonding.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.12
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• pp.1923-1930
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• 2004

This paper presents digital microflow controllers(DMFC), where a fluidic digital-to-analog converter(DAC) is used to achieve high-linearity, fine-level flow control for applications to precision biomedical dosing systems. The fluidic DAC, composed of binary-weighted flow resistance, controls the flow-rate based on the ratio of the flow resistance to achieve high-precision flow-rate control. The binary-weighted flow resistance has been specified by a serial or a parallel connection of an identical flow resistor to improve the linearity of the flow-rate control, thereby making the flow-resistance ratio insensitive to the size uncertainty in flow resistors due to micromachining errors. We have designed and fabricated three different types of 4-digit DMFC: Prototype S and P are composed of the serial and the parallel combinations of an identical flow resistor, while Prototype V is based on the width-varied flow resistors. In the experimental study, we perform a static test for DMFC at the forward and backward flow conditions as well as a dynamic tests at pulsating flow conditions. The fabricated DMFC shows the nonlinearity of 5.0% and the flow-rate levels of 16(2$^{N}$) for the digital control of 4(N) valves. Among the 4-digit DMFC fabricated with micromachining errors, Prototypes S and P show 27.2% and 27.6% of the flow-rate deviation measured from Prototype V, respectively; thus verifying that Prototypes S and P are less sensitive to the micromachining error than Prototype V.V.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.1
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• pp.81-89
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• 1999

The fabrication process for miniaturizing the Electronic Article Surveillance (EAS) sensor was studied using micromachining technique. Two types of sensor structure, free standing membrane type and diving beard type, were proposed and researched for establishing the fabrication process. The membrane type structure was easy to change the sensor shape but had the limitation for miniaturizing, because the size of the sensor depends on the silicon substrate thickness. The diving board type structure has the advantage of miniaturization and of free motion. Since the elastic modulus is not trio high, SiN film is expected to be adequate for the supporting membrane of magnetic sensor. The selectivity of $H_2O_2$for sputtered W with respect to Fe-B-Si, which was studded for magnetic sensor materials, was high enough to be removed after using as a protection layer. Therefore, the diving board type process using the silicon nitride film for the supporter of the sensor material and the sputtered W for protection layer is expected to be useful fur miniaturizing the Electronic Article Surveillance (EAS) sensor.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.105-111
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• 2000

Micronization of sensor is a trend of the silicon sensor development with regard to a piezoresistive silicon pressure sensor, the size of the pressure sensor diaphragm have become smaller year by year, and a microaccelerometer with a size less than 200~300${\mu}{\textrm}{m}$ has been realized. Over the past four or five years, numerical modeling of microsensors and microstructures has gradually been developed as a field of microelectromechanical system(MEMS) design process. In this paper, we study some of the micromachining processes of single crystal silicon(SCS) for the microaccelerometer, and their subsequent processes which might affect thermal and mechanical loads. The finite element method(FEM) has been a standard numerical modeling technique extensively utilized in structural engineering discipline for component design of microaccelerometer. Temperature rise sufficiently low at the suspended beams. Instead, larger temperature gradient can be seen at the bottom of paddle part. The center of paddle part becomes about 5~2$0^{\circ}C$ higher than the corner of paddle and suspended beam edges.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.10
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• pp.1089-1095
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• 2012

Laser beam machining (LBM) using nanosecond pulsed laser is widely known to be rapid and non-wear process for micromachining. However, the quality itself cannot meet the precision standard due to the recast layer and heat affected zone. In this paper, a fabrication method for machining micro features in stainless steel using a hybrid process of LBM using nanosecond pulsed laser and electrochemical etching (ECE) is reported. ECE uses non-contacting method for precise surface machining and selectively removes the recast layer and heat affected zone produced by laser beam in an effective way. Compared to the single LBM process, the hybrid process of LBM and ECE enhanced the quality of the micro features.