• 제목/요약/키워드: Chip flow

검색결과 316건 처리시간 0.025초

초정밀 고속가공 공정에서의 변형율속도를 고려한 전산 시뮬레이션 해석에 관한 연구 (A Study on Computational Analysis of Ultraprecsion High-speed Machining Process Considering the Strain Rate Effect)

  • 신보성;제태진
    • 한국기계가공학회지
    • /
    • 제5권2호
    • /
    • pp.3-9
    • /
    • 2006
  • HSM(High-speed Machining) is widely used in rapid manufacturing of precision products and molds of various materials. Improvement in cutting efficiency is one of the important subjects in the HSM process. To analyse the dynamic behavior during a very short cutting time, the computational analysis code, LS-DYNA3D, was employed for the simulation of the mechanism of HSM for aluminium 7075. This cutting mechanism includes some difficult points in simulation, for example, material and geometrical non-linearity, high-speed dynamic impact, contact with friction, etc. In this paper, a finite element model considering the strain rate effect is proposed to predict the cutting phenomena such as chip deformation, strain and stress distributions, which will help us to design the HSM process.

  • PDF

다중 적층 금속의 선삭가공에 대한 FEM 해석 (FEM Analysis of Turning Multi-layer Metal)

  • 김기선
    • 한국기계가공학회지
    • /
    • 제10권4호
    • /
    • pp.57-63
    • /
    • 2011
  • The aim of this study is to analyze turning process using commercial FEM simulation code. Various simulation models of orthogonal cutting process for 3 layers of metallic material have been simulated and analyzed. The workpiece material used for the orthogonal plane-strain metal cutting simulation consists of three layers, which are Allow Tool Steel, Aluminum and Stainless Steel. The finite element model is composed of a deformable workpiece and a rigid tool. The tool penetrates through the workpiece at a constant speed and constant feed rate. As an analytical result, detailed cutting temperature, strain, pressure, residual stress for both a tool and each layer of workpiece were obtained during the turning process. It has been closely observed that the chip flow curve deforms continuously.

최적 범위내에서 WLS인 게이트 수가 최대가 되는 입력 벡터를 이용한 게이트 수정 기법 (A Gate Modification Method Using the Input Vector Maximizes the Number of Gates in WLS within the Optimum Range)

  • 성방현;박혜성;김석윤
    • 전기학회논문지
    • /
    • 제56권4호
    • /
    • pp.745-750
    • /
    • 2007
  • In this paper, we propose a new gate modification method using the input vector maximizes the number of gates in WLS within the optimum range of the minimum leakage power. We prove that MLV is not always the optimal solution, and that the leakage power and area can decrease when modifying the gates using the input vector for which the number of gates in WLS is maximized within the optimum range of the minimum leakage power for the circuits applying the IVC technique and gate modification method. Using the proposed method, the gate-level description circuit can be converted to the modified circuit which reduces the leakage power by chip designer, and the modified circuit can be applied without any modification in design flow.

경사진 전극링을 이용한 고균일도의 미세 솔더범프 형성 (Formation of Fine Pitch Solder Bump with High Uniformity by the Tilted Electrode Ring)

  • 주철원;이경호;민병규;김성일;이종민;강영일
    • 한국전기전자재료학회논문지
    • /
    • 제18권9호
    • /
    • pp.798-802
    • /
    • 2005
  • The plating shape in the opening of photoresist becomes gradated shape in the fountain plating system, because bubbles from the wafer surface are difficult to escape from the deep openings, vias. In this paper, the bubble flow from the wafer surface during plating process was studied and we designed the tilted electrode ring to get uniform bump height on all over the wafer and evaluated the film uniformity by SEM and $\alpha-step$. In a-step measurement, film uniformities in the fountain plating system and the tilted electrode ring contact system were $\pm16.6\%,\;\pm4\%$ respectively.

다중경로 페이딩 전송로에서 직접시퀀스 확산대역 다원접속 시스템의 포착성능 (Acquisition performance of a direct-sequence spread-specturm multiple-access system in a multipath fading channel)

  • 김진영;이재홍
    • 한국통신학회논문지
    • /
    • 제21권5호
    • /
    • pp.1230-1239
    • /
    • 1996
  • This paper analyzes matched-filter acquistion performance of a direct-sequence spread-specturm multiple-access system in a Rayleigh fading channel. For an application of multiple access system, multiple access interference is considered in the performance analysis. A signal flow graph technique is used to derive mean acquisition time in terms of detection and false alarm probabilities. As aresult of performance analysis, it is shown that mean acquisition time increases as fading rate becomes faster andthe numbre of users increases, and it decreases as a matched-filter length becomes logner. The variation of parameter values hs much influence on acquisition performance as SNR/chip becomes smaller.

  • PDF

젤라틴 기공유도물질과 유리모세관 장치를 이용한 다공성 PLGA 미세섬유의 제조 (Preparation of Porous PLGA Microfibers Using Gelatin Porogen Based on a Glass Capillary Device)

  • 김철민;김규만
    • 한국정밀공학회지
    • /
    • 제33권1호
    • /
    • pp.63-67
    • /
    • 2016
  • We present a method of fabricating poly (lactic-co-glycolic acid) (PLGA) porous microfibers using a pore template. PLGA microfibers were synthesized using a glass capillary tube in a poly-(dimethylsiloxane) (PDMS) microfluidic chip. Gelatin solution was used as a porous template to prepare pores in microfibers. Two phases of PLGA solutions in different solvents-DMSO (dimethyl sulfoxide) and DCM (dichloromethane)-were used to control the porosity and strength of the porous microfibers. The porosity of the PLGA microfibers differed depending on the ratio of flow rates in the two phases. The porous structure was formed in a spiral shape on the microfiber. The porous structure of the microfiber is expected to improve transfer of oxygen and nutrients, which is important for cell viability in tissue engineering.

피에조 이송기구를 이용한 초소형 선반 (A Micro Turning Lathe Using Piezo Feed Driver)

  • 고태조;정종운;정병묵;김희술
    • 한국정밀공학회지
    • /
    • 제22권11호
    • /
    • pp.151-158
    • /
    • 2005
  • Micro-machine tool is essential in the micro/meso cutting for the sake of saving of space, resources, and energy. In this research, a micro-turning lathe was fabricated with piezoelectric feed drive mechanism, and motion of each axis was generated by stepwise mechanism with two piezo actuators. The resolution to drive the axis was $0.05{\mu}m$ and position accuracy less than $2{\mu}m$ was assured. From the positioning experiment, piezo feed mechanism is good enough for the micro machine tools. Many fuming experiments were carried out with diamond-cutting tools to evaluate cutting capability of a machine tool. Continuous flow type chip could be obtained even if the cutting speed was very low due to small diameter of workpiece. However, thorough investigation about machineability in micro/meso cutting is inevitable to assure high quality surface roughness in micro machine tool.

패킷프로세서 기반의 홈게이트웨이용 스위치칩 개발 (Development of the QoS Switch Chip with Packet Processors for the Home Gateway)

  • 안정균;김성수;김대환;이춘영
    • 한국정보통신설비학회:학술대회논문집
    • /
    • 한국정보통신설비학회 2006년도 하계학술대회
    • /
    • pp.134-140
    • /
    • 2006
  • 홈 게이트웨이가 가져야 하는 기능에 대한 요구사항을 분석하고 통신사업자의 관점에서, QoS 기능과 IP 주소변환 기능을 중심으로 세부적인 스위칭 칩의 기능과 성능을 규정하였다. QoS 기능, 패킷 필터링 기능, 그리고 IPv6 주소체계 도입 등과 같이 급변하는 네트워크의 요구사항을 유연하게 수용하여, 칩의 기능과 성능을 수정하거나 추가할 수 있도록 패킷프로세서 기반으로 스위칭 칩을 설계하였으며, 홈 게이트웨이의 구성을 단순화하기 위해 스위칭 칩의 패킷 메모리와 룩업 메모리를 칩 내부에 내장하였다. 그리고 칩의 설계를 검증하기 위해 FPGA를 이용하여 6포트 스위칭 칩으로 구현하여 기능 및 성능시험을 수행하였다. NAT, Flow에 따른 패킷 분류 및 패킷 변경, SPQ, DWRR과 같은 스케줄링 등의 시험을 통하여 설계한 칩의 기능과 성능을 확인하였다.

  • PDF

난삭재 고속가공에서의 엔드밀링 공정의 절삭력 해석 (Cutting Force Analysis in End Milling Process for High-Speed Machining of Difficult-to-Cut Materials)

  • 전태수
    • 한국공작기계학회:학술대회논문집
    • /
    • 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
    • /
    • pp.359-364
    • /
    • 1999
  • Due to rapid growth of die and mould industries, it is urgently required to maximize the productivity and the efficiency of machining. In recent years, owing to the development of new kinds of material, die and mould materials are much harder and it is more difficult to cut. In this study, the workpiece SKD11(HRC45) is cut with TiAlN coated tungsten-carbide cutting tools. To find the general characteristics of difficult-to-cut materials, orthogonal turning test is performed. Orthogonal cutting theory can be expanded to oblique cutting model. The oblique cutting process in the small cutting edge element has been analyzed as orthogonal cutting process in the plane containing the cutting velocity vector and chip-flow vector. Hence, with the orthogonal cutting data obtained from orthogonal turning test, the cutting forces can be analyzed through oblique cutting model. The simulation results have shown a fairy good agreement with the test results.

  • PDF

IC 칩 냉각용 초소형 히트 파이프의 제작 및 성능 평가 (Fabrication and Characteristics Test of Micro Heat Pipe Array for IC Chip Cooling)

  • 박진성;최장현;조형철;조한상;양상식;유재석
    • 대한전기학회논문지:전기물성ㆍ응용부문C
    • /
    • 제50권7호
    • /
    • pp.351-363
    • /
    • 2001
  • This paper presents an experimental investigation on the heat trensfer characteristic of micro pipe (MHP) array with 38 triangular microgrooves. A heat pipe is an effective heat exchanger operating without external power. The heat pipe transfers heat by means of the latent heat of vaporization and two-phase fluid flow driven by the capillary force. The overall size of the MHP array can be put undermeath a microelectonic die and integrated into the electrronic package of a microelectronin device to dissipate the heat from the die. The MHP array is fabricated by micromachining with a silicon wafer and a glass substrate. The MHP was filled with water and sealed. The experimental results show the temperature decrease of 12.1$^{\circ}C$ at the evaporator section for the input power of 5.9 W and the improvement of 28% in the heat transfer rate.

  • PDF