• 제목/요약/키워드: Embossing Technique

검색결과 32건 처리시간 0.025초

그루브를 이용한 표면형상변형 동특성 변경법 :HDD 커버에 대한 적용 (Structural Dynamics Modification Using Surface Grooving Technique : Application to the HDD Cover model)

  • 박미유;박영진;박윤식
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 추계학술대회논문집
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    • pp.826-829
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    • 2004
  • Structural Dynamics Modification is very effective technique to improve structure's dynamic characteristics by adding or removing auxiliary structures, changing material property, changing shape of structure. In this research, using the surface grooving technique, shape of base structure was changed to improve its first natural frequency. Utilizing the result of frequency variation analysis, groove shape was formed gathering the many small embossing elements. For this process, Criterion Factor was introduced. To reduce its amount of calculation, the range of target area was restricted to their neighboring area and initial grooving point was selected using high-strain energy. This surface grooving technique was successfully applied to the HDD cover model.

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임의의 형태를 갖는 흠을 이용한 표면형상변형을 통한 동특성 변경 (Structural Dynamics Modification Using Surface Grooving Technique)

  • 박미유;박영진;박윤식
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.859-863
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    • 2004
  • Structural Dynamics Modification is very effective technique to improve structure's dynamic characteristics by adding or removing auxiliary structures, changing material property, changing shape of structure. In this research, using the surface grooving technique, shape of base structure was changed to improve its first natural frequency. Utilizing the result of sensitivity analysis, groove shape was formed gathering the many small embossing elements. For this process, Sensitivity Criterion Factor was introduced. To reduce its amount of calculation, the range of target area was restricted to their neighboring area and that result was very successful.

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LIGA 공정을 이용한 평면형 광소자용 Ni 마스터 제작 (Fabrication of Ni master for the replication of planar optical devices by LIGA process)

  • 김진태;정명영
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.945-949
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    • 2003
  • LIGA(Lithographie Galvanoformung Abformung), a fabrication method for the production of microstructrues with a high aspect ratio, is now playing an important role in a fabrication of polymeric optical waveguide device as the replication processes have been developed such as hot embossing and injection molding. The present report deals with the fabrication of Ni master used for the replication of multi-mode polymeric optical waveguide. With the basic technological features in the sequence of the LIGA technique, we fabricated Ni master with 12 channel microstructures of $100\;{\times}\;100{\mu}m\;^2{\times}\;60mm$, and achieved an accuracy of ${\pm}1\;{\mu}m$. Manufactured polymeric optical wavegude with the same using hot embossing process has also the same accuracy and approved its mass production capability.

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그루브를 이용한 표면형상변형 동특성 변경법 : HDD 커버에 대한 적용 (Structural Dynamics Modification Using Surface Grooving Technique: Application to HDD Cover Model)

  • 박미유;박영진;박윤식
    • 한국소음진동공학회논문집
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    • 제15권3호
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    • pp.341-345
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    • 2005
  • Structural Dynamics Modification (SDM) is a very effective technique to improve structure's dynamic characteristics by adding or removing auxiliary structures, changing material properties and shape of structure. Among those of SDM technique, the method to change shape of structure has been mostly relied on engineer's experience and trial-and-error process which are very time consuming. In order to develop a systematic method to change structure shape, surface grooving technique is studied. In this work, the shape of base structure was modified to improve its dynamic characteristics such as natural frequencies via surface grooving technique. Grooving shape was formed by mergingthe neighboring small embossing elements after analyzing frequency increment sensitivities of all the neighboring emboss elements. For this process, Criterion Factor was introduced and the initial grooving was started from the element having highest strain energy and the grooving is expanded into neighboring element. The range of targeting grooving area to check its frequency variations restricted to their neighboring area to reduce the computation effort. This surface grooving technique was successfully applied to a hard disk drives (HDD) cover model to raise its natural frequency by giving some groove on its surface.

LIGA공정을 이용한 정밀 고분자 광도파로 제작 (Fabrication of Polymeric Optical Waveguide by LIGA)

  • 김진태;김병철;최춘기;윤근병;정명영
    • 대한기계학회논문집A
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    • 제27권6호
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    • pp.997-1006
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    • 2003
  • LICA technique evolved as a basic fabrication process fur micro-structure. The present report deals with the basic technological features in the sequence of the LIGA technique such as deep x-ray lithography(DXRL), electroplating, and moulding processes at Pohang Light Source (PLS). We designed 3-D structured master for fabrication of polymeric optical wavegude and manufactured polymeric optical wavegude with the same using hot embossing process. Polymeric optical waveguide could be produced with ${\pm}$ 1 $\mu\textrm{m}$ accuracy and good surface roughness.

연속체 개념에 기반한 나노 임프린트 공정해석 연구 (Numerical Analysis Based on Continuum Hypothesis in Nano-imprining process)

  • 김현칠;이우일
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 추계학술대회논문집
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    • pp.333-338
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    • 2003
  • Nano-imprint lithography(NIL) is a polymer embossing technique, capable of transferring nano-scale patterns onto a thin film of thermoplastics such as polymethyl methacrylate(PMMA) using this parallel process. Feature size down 10 nm have been demonstrated. In NIL, the pattern is formed by displacing polymer material, which can be squeeze flow of a viscous liquid. Due to the size of the pattern, a thorough understood of the process through experiments may be very different. Therefore we nead to resort to numerical simulation on the embossing process. Generally, there are two ways of numerical simulation on nano-scale flow, namely top-down and bottom-up approach. Top-down approach is a way to simulate the flow assuming that polymer is a continuum. On the contrary, in the bottom-up approach, simulation is peformed using molecular dynamics(MD). However, as latter method is not feasible yet. we chose the top-down approach. For the numerical analysis, two dimensional moving grid was used since the moving grid can predict the flow front. Effects of surface tension as well as the slip at the boundary were also considered.

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하프피어싱에 의한 원형돌기의 성형 및 마킹공정에의 응용 (Forming of Circular Protrusion by Half-Piercing and its Application to Marking of Sheet Metal)

  • 정효기;김종호
    • 소성∙가공
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    • 제21권3호
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    • pp.202-206
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    • 2012
  • Marking is a process that engraves letters or a pattern onto the surface of sheet metal. During marking, it is important to set the proper working conditions for clarity of the letters. In this study a simple case for forming circular protrusions by half-piercing and embossing was initially attempted to determine the working conditions which gave good results with respect to shape accuracy. Corner-radius and flatness of circular protrusions made under several experimental conditions were measured and compared. It is shown that the precision of protrusions by half-piercing is superior to that of embossing, and the clearance between punch and die exerts a strong influence on the shape accuracy rather than the penetration percentage into the thickness of the sheet metal. The marking dies for "SNUT" letters, as an example, by applying the above results were manufactured with four different clearances. The working variables for the experiment were clearance and marking depth. For the very shallow depth of 0.1mm the letters were not clearly read. Letters marked under other conditions were easily distinguished with increasing marking depth. It was confirmed that the half-piercing technique with proper values of the working variables gives good quality for the marking of sheet metal.

둥근 엠보싱 형상이 있는 슬라이더 베어링의 경사도에 따른 윤활효과 (Lubrication Effect of Slider Bearing with Round Embossed Surface According to Its Slider Slope)

  • 진도훈;윤문철
    • Tribology and Lubricants
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    • 제30권5호
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    • pp.284-290
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    • 2014
  • The influence of round embossed surface on slider bearing characteristics and its load carrying capacity is discussed for thin film effect of embossed slider bearing. For the numerical computation of lubrication parameters such as pressure, load capacity and shear stress that are normalized and a Reynolds equation is used for the analysis of embossed slider bearing characteristics. For this purpose, the finite difference method of central difference scheme is used in this study. In a slider bearing with embossed form, several simulation parameters such as pressure, load capacity and shear stress of the bearing can be obtained according to independent parameters such as the slope of the slider bearing and number of embossing in the upper slider. Also this results can be summarized and be stored in sequential data file for latter analysis. After all, their distribution of the pressure and shear stress parameters can be displayed and be analyzed easily by using the developed program with matlab GUI technique. The independent parameters such as a number of embossing and a slope of the embossed surface slider are used for discussing simulation parameters of pressure distribution, shear stress and load carrying capacity of the round embossing. These study results reported in this paper should be applied to the other shaped slider bearing with a rectangular embossed surface or rectangular waved surface.

엠보스를 이용한 동특성 변경 : 신경망과 스트레인 에너지를 이용한 방법의 비교 연구 (Structural Dynamics Modification with Embossing: A Comparison Study Between Neural Network and Modal Dynamic Strain Energy)

  • 김정욱;박윤식;박영진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 추계학술대회논문집
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    • pp.219-222
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    • 2004
  • This research is about SDM (Structural Dynamics Modification) technique using embosses. SDM using embosses do not need to add additional mass element ana model of embosses and resulting huge calculation for getting analytical solution of an embossed structure. The object of this research is to suggest a method to guide placing embossment in a structure to raise its natural frequencies. Two methods to optimize model with embossing are suggested, indepuldently. The former is response surface analysis by neural network. And the latter is an indirect method using modal dynamic strain energy.

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