• 제목/요약/키워드: micro scale

검색결과 1,171건 처리시간 0.022초

Effect of Scale-down of Structure on Dynamic Characteristic Parameters in Bolted-Joint Beams (구조물의 소형화가 볼트 결합부의 동특성 파라미터에 미치는 영향 분석)

  • Kim, Bong-Suk;Lee, Seong-Min;Song, Jun-Yeob;Lee, Chang-Woo;Lee, Soo-Hun
    • Journal of the Korean Society for Precision Engineering
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    • 제24권3호
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    • pp.108-116
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    • 2007
  • To overcome many defects such as the high product cost, large energy consumption, and big space capacity in conventional mechanical machining, the miniaturization of machine tool and micro factory systems has been envisioned recently. The object of this paper is to research the effect of dynamic characteristic parameters in bolted-joint beams, which is widely applied to the joining of mechanical structures in order to identify structural system characteristics and to predict dynamic behavior according to scale-down from macro to micro system as the development of micro/meso-scale machine tool and micro factories. Modal parameters such as the natural frequency, damping ratio, and mode shape from modal testing and dynamic characteristics from finite element analysis are extracted with all 12 test beam models by materials, by size, and by joining condition, and then the results obtained by both methods are compared.

Micro-scale Thermal Sensor Manufacturing and Verification for Measurement of Temperature on Wafer Surface

  • Kim, JunYoung;Jang, KyungMin;Joo, KangWo;Kim, KwangSun
    • Journal of the Semiconductor & Display Technology
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    • 제12권4호
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    • pp.39-44
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    • 2013
  • In the semiconductor heat-treatment process, the temperature uniformity determines the film quality of a wafer. This film quality effects on the overall yield rate. The heat transfer of the wafer surface in the heat-treatment process equipment is occurred by convection and radiation complexly. Because of this, there is the nonlinearity between the wafer temperature and reactor. Therefore, the accurate prediction of temperature on the wafer surface is difficult without the direct measurement. The thermal camera and the T/C wafer are general ways to confirm the temperature uniformity on the heat-treatment process. As above ways have limit to measure the temperature in the precise domain under the micro-scale. In this study, we developed the thin film type temperature sensor using the MEMS technology to establish the system which can measure the temperature under the micro-scale. We combined the experiment and numerical analysis to verify and calibrate the system. Finally, we measured the temperature on the wafer surface on the semiconductor process using the developed system, and confirmed the temperature variation by comparison with the commercial T/C wafer.

Current Status of Biomedical Applications using 3D Printing Technology (3D프린팅 활용 생체의료분야 기술동향)

  • Park, Suk-Hee;Park, Jean Ho;Lee, Hye Jin;Lee, Nak Kyu
    • Journal of the Korean Society for Precision Engineering
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    • 제31권12호
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    • pp.1067-1076
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    • 2014
  • To date, biomedical application of three-dimensional (3D) printing technology remains one of the most important research topics and business targets. A wide range of approaches have been attempted using various 3D printing systems with general materials and specific biomaterials. In this review, we provide a brief overview of the biomedical applications using 3D printing techniques, such as surgical tool, medical device, prosthesis, and tissue engineering scaffold. Compared to the other applications of 3D printed products, the scaffold fabrication should be performed with careful selection of bio-functional materials. In particular, we describe how the biomaterials can be processed into 3D printed scaffold and applied to tissue engineering area.

Micro-scale Observation of Corrosion of Hot-Dip Aluminized 11% Cr Stainless Steel

  • Cho, Min-Seung;Park, Choong-Nyeon;Park, Chan-Jin
    • Corrosion Science and Technology
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    • 제18권3호
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    • pp.73-77
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    • 2019
  • Hot-dip aluminized coating has been widely used to protect steel substrate against corrosion. In this study, the corrosion behavior of hot-dip aluminized type 409L (11% Cr) stainless steel (SS) was investigated using macro- and micro-scale polarization tests. An Al-Fe-Si alloy layer that was formed due to inter-diffusion of alloying elements between Al coating and SS substrate was observed between Al coating and 409L SS substrate. In both macro- and micro-scale polarization tests, the corrosion potential ($E_{corr}$) of the 409L SS substrate was much nobler than that of the Al coating and alloy layer. $E_{corr}$ of the alloy layer was between that of Al coating and 409L SS substrate. This indicates that the alloy layer can act as a buffer between the more active Al coating and the nobler SS substrate for pit growth in aluminized SS. The presence of the alloy layer appears to be helpful in hindering pitting corrosion of aluminized SS.

Development of Method for In-situ Micro-Scale Observation of Stress Corrosion Cracking in High-Temperature Primary Water Environment (원전 고온 1차수 환경에서 응력부식균열의 실시간 마이크로 스케일 관찰 방법 개발)

  • Jung-Ho Shin;Jong-Yeon Lee;Sung-Woo Kim
    • Corrosion Science and Technology
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    • 제22권4호
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    • pp.265-272
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    • 2023
  • The aim of this study was to develop a new in-situ observation method and instrument in micro-scale to investigate the mechanism of stress corrosion cracking (SCC) initiation of Ni-base alloys in a high temperature water environment of pressurized water reactors (PWRs). A laser confocal microscope (LCM), an autoclave with diamond window view port, and a slow strain-rate tester with primary water circulation loop system were components of the instrument. Diamond window, one of the core components of the instrument, was selected based on its optical, chemical, and mechanical properties. LCM was used to observe the specimen in micro-scale, considering the experimental condition of a high-temperature primary water environment. Using in-situ method and instrument, it is possible to observe oxidation and deformation of specimen surface in micro-scale through the diamond window in a high-temperature primary water in real-time. The in-situ method and instrument developed in this work can be utilized to investigate effects of various factors on SCC initiation in a high-temperature water environment.

Experimental Study of Dynamic Behavior of a Water Droplet on Diverse Wrinkling Surfaces (마이크로 표면주름 구조에 따른 물방울 동적거동에 관한 실험적 연구)

  • Baek, Dae Hyeon;Zhao, Zhijun;Park, Sang-Hu
    • Journal of the Korean Society for Precision Engineering
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    • 제32권6호
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    • pp.577-585
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    • 2015
  • We fabricated multi-scale such as macro-, micro-, and multi-scale wrinkles by using repetitive volume dividing (RVD) method and thermal curing process. Also wrinkle surface was modified with coating of a self-assembled monolayer (SAM). We measured the contact angle of each wrinkled surface, and observed the behavior of droplets on sloping surface. Through experimental study, we found out that the contact angle was much higher in case of multi-scale and SAM coated wrinkles. And micro-scale wrinkle showed a high contact angle comparing with that of macro-scale wrinkle. Dynamic behaviors of a water droplet like sliding velocity on diverse wrinkled surfaces were dependent on their static contact angles. These results showed that hydro-dynamic characteristics were changed depending on the wrinkle structure and the material forming the wrinkle. These dynamic characteristics can be utilized in bio-chip, microfluidics, and many others in order to control easily chemical reactivity.

On the analysis of micro pattern forming on the thin sheet metal (마이크로 박판 미세 패턴 성형공정에 대한 해석적 연구)

  • Cha, S.H.;Shin, M.S.;Kim, J.H.;Kim, J.B.;Lee, H.J.;Song, J.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 한국소성가공학회 2009년도 추계학술대회 논문집
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    • pp.53-56
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    • 2009
  • Roll forming process is one of important metal processing technology because the process is simple and economical. These days, roll forming process is tried to be employed in manufacturing the circuit board, barrier ribs and solar cell plate for productivity. However, it is difficult to apply to the forming of micro scale or sub-micro scale pattern. In this study, the roll forming processing for the micro scale is designed and analyzed. In this study, the forming of micro pattern for solar cell plate by incremental roll forming process is analyzed. The solar cell plate may have thousands of patterns, and the analysis of forming considering all the patterns is impossible due to the computational costs. In this study, analyses are carried out for various numbers of patterns and the results are compared. It is shown that the analyses results with four row patterns and twelve row patterns are same. So, it is considered that the analysis can be carried out for only four rows of pattern for the design of incremental roll forming process. Also experiment is carried out process that is designed through simulation.

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Design of Roll-to-Roll Forming Process for Micro Pattern on the Thin Sheet Metal by Finite Element Analysis (유한요소해석을 이용한 마이크로 박판 미세 패턴 롤-롤 성형공정 설계)

  • Cha, S.H.;Shin, M.S.;Lee, H.J.;Kim, J.B.
    • Transactions of Materials Processing
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    • 제19권3호
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    • pp.167-172
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    • 2010
  • Roll-to-roll forming process is one of important metal processing technology because the process is simple and economical. These days, with these merits, roll-to-roll forming process is tried to be employed in manufacturing the circuit board, barrier ribs and solar cell plate. However, it is difficult to apply to the forming of micro scale or sub-micro scale pattern. In this study, the roll forming processing for the micro scale is designed and analyzed. The forming of micro pattern for small electric device such as LCD panel by incremental roll forming process is analyzed. Firstly, the optimum analysis conditions are found by several analyses. And then, formability is analyzed for various protrusion shapes at various forming temperatures. The formability is evaluated in terms of filling ratio and damage value. The filling ratio is defined from the tool geometry and critical damage is determined from the analysis of uniaxial tensile test. Finally, optimum forming conditions that guarantee the successful forming are found.

The Characteristics of Focused Ion Beam Utilized Silicon Mold Fabrication on the Micro/Nano Scale (집속이온빔을 이용한 마이크로/나노스케일에서의 실리콘 금형 가공 특성)

  • Kim, Heung-Bae;Noh, Sang-Lai
    • Journal of the Korean Society for Precision Engineering
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    • 제28권8호
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    • pp.966-974
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    • 2011
  • The use of ion beams in the micro/nano scale is greatly increased by technology development. Especially, focused ion beams (FIBs) have a great potential to fabricate the device in sub micro scale. Nevertheless, FIB has several limitations, surface swelling in low ion dose regime, precipitation of incident ions, and the redeposition effect due to the sputtered atoms. In this research, we demonstrate a way which can be used to fabricate mold structures on a silicon substrate using FIBs. For the purpose of the demonstration, two essential subjects are necessary. One is that focused ion beam diameter as well as shape has to be measured and verified. The other one is that the accurate rotational symmetric model of ion-solid interaction has to be mathematically developed. We apply those two, measured beam diameter and mathematical model, to fabricate optical lenses mold on silicon. The characteristics of silicon mold fabrication will be discussed as well as simulation results.

On the effective analysis method of micro pattern forming on the thin sheet metal (마이크로 박판 미세 패턴 성형공정에 대한 해석 효율성 연구)

  • Cha, S.H.;Shin, M.S.;Kim, J.H.;Kim, J.B.;Lee, H.J.;Song, J.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 한국소성가공학회 2009년도 춘계학술대회 논문집
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    • pp.56-59
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    • 2009
  • Roll forming process is one of important metal processing technology because the process is simple and economical. These days, roll forming process is tried to be employed in manufacturing the circuit board, barrier ribs and solar cell plate for productivity. However, it is difficult to apply to the forming of micro scale or sub-micro scale pattern. In this study, the roll forming processing for the micro scale is designed and analyzed. In this study, the forming of micro pattern for solar cell plate by incremental roll forming process is analyzed. The solar cell plate may have thousands of patterns, and the analysis of forming considering all the patterns is impossible due to the computational costs. In this study, analyses are carried out for various numbers of patterns and the results are compared. It is shown that the analyses results with four row patterns and twelve row patterns are same. So, it is considered that the analysis can be carried out for only four rows of pattern for the design of incremental roll forming process.

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