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비전도성 에폭시를 사용한 RF-MEMS 소자의 웨이퍼 레벨 밀봉 실장 특성

  • 박윤권;이덕중;박흥우;송인상;박정호;김철주;주병권
    • 한국마이크로전자및패키징학회:학술대회논문집
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    • 한국마이크로전자및패키징학회 2001년도 추계 기술심포지움
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    • pp.129-133
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    • 2001
  • In this paper, hermetic sealing was studied fur wafer level packaging of the MEMS devices. With the flip-chip bonding method, this B-stage epoxy sealing will be profit to MEMS device sealing and further more RF-MEMS device sealing. B-stage epoxy can be cured 2-step and hermetic sealing can be obtained. After defining $500{\mu}{\textrm}{m}$-width seal-lines on the glass cap substrate by screen printing, it was pre-baked at $90^{\circ}C$ for about 30 minutes. It was then aligned and bonded with device substrate followed by post-baked at $175^{\circ}C$ for about 30 minutes. By using this 2-step baking characteristic, the width and the height of the seal-line were maintained during the sealing process. The height of the seal-line was controlled within $\pm0.6${\mu}{\textrm}{m}$ and the strength was measured to about 20MPa by pull test. The leak rate of the epoxy was about $10^7$ cc/sec from the leak test.

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나노 크기의 세 채널 플라즈마 방향성 결합기의 전력분배 (Power Splitting of Plasmonic Directional Couplers with Nano-scale Three Channels)

  • 호광춘
    • 한국인터넷방송통신학회논문지
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    • 제11권3호
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    • pp.47-52
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    • 2011
  • 세 채널로 구성된 나노 크기의 플라즈마 방향성 결합기가 모드 결합효과와 립형 전송구조를 사용하여 설계되었다. 종방향 모드 전송선로 해석법을 이용하여 방향성 결합기에서 전파하는 빛의 전파특성과 설계특성들을 분석하였다. 전력분배기로 동작하는 플라즈마 방향성 결합기는 약 200~250 nm의 전송 폭을 갖는 나노 크기로 설계하였다. 최적의 전력분배율을 얻기 위하여 중심 채널의 폭 변화에 따른 전송 모드들의 굴절률을 분석하였다. 결국, 하향 채널에서 입사된 광 신호를 각 채널을 통하여 출력하는 나노 크기의 플라즈마 방향성 결합기가 설계되었다.

마그네슘 페라이트에서 강자성 공명의 시료 크기 의존성 연구 (A Study on Sample Size Dependence of Ferromagnetic Resonance in Polycrystalline Magnesium Ferrites)

  • 한기태;백종규
    • 한국세라믹학회지
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    • 제32권2호
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    • pp.163-170
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    • 1995
  • Sample size effect on ferromagnetic resonance (FMR) in polycrystalline MgFe2O4 has been investigated. The signal intensity (SI), resonance field (Hres) and line width (ΔH) were found to increase proportionally to r3 with the increase of sample radius. The r3-depencence of SI means the complete penetration of rf-field into the sample, and the broadening of ΔH due to the sample size appears to be closely related to the amount of scattering sources like pores. Meanwhile, the values of Hres (0) and ΔH (0) obtained by extrapolating the data of Hres (r) and ΔH (r) measured at several sizes to r=0, were in good agreement with those calculated using the Schlomann's equations for internal field and ΔH, respectively. This result indicates that the discrepancy between the measured FMR parameters and those calculated by Schlomann's equation could be ascribed to the effect of sample size. Thus it is suggested that the size effect on FMR should be removed for the analysis of the FMR parameters. Meanwhile, our result for the size dependance of ΔH was found to be contradictory to those reported by Dionne, where ΔH 1/r at a given surface roughness. This discrepancy appears to arise from the difference in the definition of reading the line width.

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A 12-bit Hybrid Digital Pulse Width Modulator

  • Lu, Jing;Lee, Ho Joon;Kim, Yong-Bin;Kim, Kyung Ki
    • 한국산업정보학회논문지
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    • 제20권1호
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    • pp.1-7
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    • 2015
  • In this paper, a 12-bit high resolution, power and area efficiency hybrid digital pulse width modulator (DPWM) with process and temperature (PT) calibration has been proposed for digital controlled DC-DC converters. The hybrid structure of DPWM combines a 6-bit differential tapped delay line ring-mux digital-to-time converter (DTC) schema and a 6-bit counter-comparator DTC schema, resulting in a power and area saving solution. Furthermore, since the 6-bit differential delay line ring oscillator serves as the clock to the high 6-bit counter-comparator DTC, a high frequency clock is eliminated, and the power is significantly saved. In order to have a simple delay cell and flexible delay time controllability, a voltage controlled inverter is adopted to build the deferential delay cell, which allows fine-tuning of the delay time. The PT calibration circuit is composed of process and temperature monitors, two 2-bit flash ADCs and a lookup table. The monitor circuits sense the PT (Process and Temperature) variations, and the flash ADC converts the data into a digital code. The complete circuits design has been verified under different corners of CMOS 0.18um process technology node.

Photometric Reverberation Mapping of Active Galactic Nuclei with Medium-band Filters and a Large FOV Telescope.

  • Hwang, Sungyong;Im, Myungshin;Ji, Tae-Geun;Lee, Hye-In;Pak, Soojong
    • 천문학회보
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    • 제42권2호
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    • pp.78.1-78.1
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    • 2017
  • We present a noble method to determine BH mass of many AGNs directly through reverberation mapping using a small telescope with wide-field of view. In 2017 August we installed five medium-band filters to a 0.25m diameter $5deg^2$ FOV telescope at the McDonald observatory. The width of these filters (FWHM ~ 50nm) are matched to the broad line width of type-1 AGNs at various redshifts. From recently obtained data, about r ~ 19 magnitude AGNs can be detected in line component with 150s exposure. With this magnitude limit, about 20~30 AGNs can be studied in one field. We plan to carry out at one day cadence observation over 20~30 fields, enabling us to monitor up to ~1000 AGNs over a wide range of variability. This poster presents out plan and early results from test observation.

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조선초기(朝鮮初期) 요선첩리(腰線帖裏) 재현에 대한 연구 (A Study on the Reproduction of Yoseon-Cheobli (腰線帖裵) of the Earlier Joseon Dynasty)

  • 김진홍;조우현
    • 복식
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    • 제61권2호
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    • pp.102-115
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    • 2011
  • This study is about reproduction of Yoseon-Cheobli excavated from Byun-su tomb in earlier Joseon Dynasty. There are three Yoseon-Cheobli in Byun-su tomb. The producing process is made in concrete by suggesting the process of producing clothing. Based on the Annals of the Joseon Dynasty, the most frequently recorded one, was reproduced by dying fabric with safflower and indigo plants. Through the research about their specific size, sewing method and construction, it have been produced in the following. First, the revealing that collar to be half-square and to compose the line in the center of collar. The width of the collar is 11.6 12.1cm. Second, the 21~22 pairs of waist lines that are 13~14cm in width fixed at intervals of 0.3cm. The method of making waist lines is twisting either fabrics or silk threads. Third, fine gathering around the part of the waist of skirt, and the size of fold surface is 0.2cm. Sewing method needs running stitch and backstitch. As the result of producing the cloth, it became to possess more ornamental features after transformation suitable to the new environment while the same remained functional features for everyday life such as a dressing shape, length of the bodice and curvy completion line of a collar strip.

TFT/LCD 시스템 패키지 전기적 특성 분석 및 설계도구의 구현 (Development of a Tool for the Electrical Analysis and Design of TFT/LCD System Package)

  • 임호남;지용
    • 전자공학회논문지A
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    • 제32A권12호
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    • pp.149-158
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    • 1995
  • This paper describes the development of a software tool LCD FRAME that may guide the analyzing process for the electrical characteristics and the design procedure for constructing the thin film transistor liquid crystal display(TFT/LCD) packages. LCD FRAME can analyze its electrical characteristics from the TFT/LCD system package configuration, and provide the design variables to meet the user's requirements. These analysis and design procedure can be done in real time according to the model at simplified package level of TFT/LCD. LCD_FRAME is an object-oriented expert system which considers package elements as objects. With this LCD_FRAME software tool, we analyzed the I-V characteristics of a-Si TFT and its signal distortion which has maximum 1.58 $\mu$s delay along the panel scan line of the package containing 480 ${\times}$ 240 pixels. We designed the package structure of maximum 6.35 $\mu$s signal delays and 3360 ${\times}$ 780 pixels, and as a result we showed that the proper structure of 20 $\mu$m scan line width, 60$\mu$m panel TFT gate width and 8 $\mu$m gate length. This LCD_FRAME software tool provides results of the analysis and the design in the form of input files of the SPICE program, text data files, and graphic charts.

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Optimal Characteristics of a Long-pulse $CO_2$Laser by Controlling SCR Firing Angle in AC Power Line

  • Noh, Ki-Kyung;Kim, Geun-Yong;Chung, Hyun-Ju;Min, Byoung-Dae;Song, Keun-Ju;Kim, Hee-Je
    • KIEE International Transactions on Electrophysics and Applications
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    • 제2C권6호
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    • pp.304-308
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    • 2002
  • We demonstrate a simple pulsed $CO_2$ laser with millisecond long pulse duration in a tube at a low pressure of less than 30 Torr. The novel power supply for our laser system switches the voltage of the AC power line (60Hz) directly. The power supply doesn't need elements such as a rectifier bridge, energy-storage capacitors, or a current-limiting resistor in the discharge circuit. To control the laser output power, the pulse repetition rate is adjusted up to 60Hz and the firing angle of SCR(Silicon Controlled Rectifier) gate is varied from 30。 to 150。. A ZCS (Zero Crossing Switch) circuit and a PIC one-chip microprocessor are used to control precisely the gate signal of the SCR. The maximum laser output of 35 W is obtained at a total pressure of 18 Torr, a pulse repetition rate of 60 Hz, and a SCR gate firing angle of 90。 . In addition, the resulting laser pulse width is approximately 3㎳(FWHM). This is a relatively long pulse width, compared with other repetitively pulsed $CO_2$ lasers.

초콜릿 소재의 3차원 프린터 개발에 관한 연구 (A Study on Development of Three-Dimensional Chocolate Printer)

  • 김규언;박근;이치범
    • 한국정밀공학회지
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    • 제34권4호
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    • pp.293-298
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    • 2017
  • In this study, we developed a 3D chocolate printer and studied the conditions needed for chocolate printing. Because chocolate is a mixture of cocoa mass, cocoa butter and sugar particles, its properties vary with temperature, and care is required in melting and extrusion. A chocolate supply unit is composed of a heating block and a syringe pump. It is integrated with a 3-axis linear robot. In order to be more accurate than the existing 3D chocolate printer is, the system was configured so that the printing line width became $430{\mu}m$. Printing performance was studied according to various parameters. The condition needed for printing lines with a stable width was discovered by the experimental design method and has been confirmed by a 2D line test. These 3D printing experiments showed that it was possible to build a 3D shape with an inclination angle of up to $45^{\circ}$ without support. Further, chocolate printing of a 3D shape has been successfully verified with the developed system.

정수장 응집제주입 최적화를 위한 플럭 모니터링 (Optimum Coagulation of Water Treatment Plant using On-line Floc Monitoring System)

  • 황환도;임상호;성규종;한영진;김영범;곽종운
    • 상하수도학회지
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    • 제23권4호
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    • pp.397-406
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    • 2009
  • This study was conducted to monitor the floc sizes forming in the mixing zone in the water treatment plant. The dosing amount of poly aluminium chloride(PAC) was determined by particle dispersion analyzer(iPDA) in the lab and field scale test. During a field test period, PAC coagulant was used and the raw water was taken from Nakdong river. PAC wad diluted to activate the coagulant, leading to bring the more homogeneous dispersion in the shorter time. To monitor the floc sizes, the unit of floc size index(FSI) was used. With increasing of raw water turbidity, FSI value was increased. Also, the increased dosing amount of PAC brought the increased FSI and with overdosing of coagulant was in turn decreased. When the PAC was fed into the raw water after dilution in a field scale test, the width of FSI was narrower compared with the feeding of the mother liquor of PAC, implying that the formed flocs are denser and more uniform sizes. The width of FSI in average was varied on depending on the basicity of coagulant. Also, dF value, fractal dimension was evalued with the different coagulants, showing from 2.01 to 2.03. On-line floc monitor was effective for the optimal dosing in the drinking water plant.