• Title/Summary/Keyword: Multilayered structure design

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Thermomechanical Analysis of Functionally Gradient Al-$SiC_{p}$ Composite for Electronic Packaging (전자패키지용 경사조성 Al-$SiC_{p}$ 복합재료의 열 . 기계적 변형특성 해석)

  • 송대현;최낙봉;김애정;조경목;박익민
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.04a
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    • pp.175-183
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    • 2000
  • The internal residual stresses within the multilayered structure with shan interface induced by the difference in thermal expansion coefficient between the materials of adjacent layers often provide the source of failure such as delamination of interfaces and etc. Recent development of the multilayered structure with functionally graded interface would be the solution to prevent this kind of failure. However a systematic thermo-mechanical analysis is needed fur the customized structural design of multilayered structure. In this study, theoretical model for the thermo-mechanical analysis is developed for multilayered structures of the Al-$SiC_p$ functionally graded composite for electronic packaging. The evolution of curvature and internal stresses in response to temperature variations is presented for the different combinations of geometry. The resultant analytical solutions are used for the optimal design of the multilayered structures with functionally graded interface as well as with sharp interface.

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Design of antireflection coationgs on the facets of a multilayered structure waveguide device (다층 구조 도파관 소자 단면에의 무반사 코팅 설계)

  • 김용곤;김부균;주흥로
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.7
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    • pp.1850-1860
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    • 1996
  • We present the results for the design ofantireflection (AR) coatings on facets of a multilayered structure waveguide device. The method, whose results agree very well with the reusults of the rigorous method in the case of a symmetric three layer structure deveice, is extended for the design of AR coatings on the facets of a multilayered structure waveguide device. the field profile in a multilayered structure waveguide necessary for the use of the extended method is obtained from the transfer matrix method. The virtual four layered structure method (VFLM) is proposed to reduce the time for the design ofAR coatings because the time for the design of AR coatings using the extended method increases as the number of layers increases. The optimum coating parameters and tolerance mapsfor two different six layered waveguide devices in Ref. [9] and [10] are obtained using the extendedmethod and the VFLM,and for the three different cases approximated as three layered waveguide devices to compare the results of each case. The results of the VFLM are similar to those of the extended methodcompared to those of the three layered structure waveguide. The main reason for the above results is that the field profile in the device calculated usingthe VFLM is similar to that calculated using the extended method compared to that for three layered structure wavegjide. We conclude that the extended method or VFLM should be used for the design of AR coatings on facets of a deice required for the facet reflectivity less than 10$^{-3}$ such as a semiconductor otical amplifier.

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Thermomechanical Analysis of Functionally Gradient $Al-SiC_p$ Composite for Electronic Packaging (전자패키지용 경사조성 $Al-SiC_p$복합재료의 열.기계적 변형특성 해석)

  • 송대현;최낙봉;김애정;조경목;박익민
    • Composites Research
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    • v.13 no.6
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    • pp.23-29
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    • 2000
  • The internal residual stresses within the multilayered structure with sharp interface induced by the difference in thermal expansion coefficient between the materials of adjacent layers often provide the source of failure such as delamination of interfaces etc. Recent development of the multilayered structure with functionally graded interface would be the solution to prevent this kind of failure. However a systematic thermo-mechanical analysis is needed for the customized structural design of multilayered structure. In this study, theoretical model for the thermo-mechanical analysis is developed for multilayered structures of the $Al-SiC_p$ functionally graded composite for electronic packaging. The evolution of curvature and internal stresses in response to temperature variations is presented for the different combinations of geometry. The resultant analytical solutions are used for the optimal design of the multilayered structures with functionally graded interface as well as with sharp interface.

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Electrical Properties of the multilayered PZT(4060)/(6040) Thin Films (PZT(4060)/(6040) 다층 박막의 전기적 특성)

  • Nam, Sung-Pill;Lee, Sung-Gap;Bea, Seon-Gi;Lee, Young-Hie
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1301-1302
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    • 2007
  • The multilayered $Pb_{1.1}(Zr_{0.4}Ti_{0.6})O_{3}$/$Pb_{1.1}(Zr_{0.6}Ti_{0.4})O_{3}/Pb_{1.1}(Zr_{0.4}Ti_{0.6})O_{3}$[PZT(4060)/(6040)/(4060)] thin films were deposited by RF sputtering method on the Pt/TiO2/SiO2/Si substrate. We investigated the effects of deposition conditions on the structural and electrical properties of the multilayered PZT thin films. All the multilayered PZT thin films showed dense and homogeneous structure without the presence of the rosette structure. The dielectric properties such as dielectric constant, loss, remanent polarization of the multilayered PZT thin film were superior to those of single composition PZT(4060) and PZT(6040) films, and those values for the multilayered PZT(10/20/10) thin film were 903, 1.01% and $25.60{\mu}C/cm^2$. This study suggests that the design of the multilayered PZT thin films capacitor with tetragonal and rhombohedral phase should be an effective method to enhance the dielectric and ferroelectric performance in devices.

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Optimization of Multilayered Foam-panel Sequence for Sound Transmission Loss Maximization (전달손실 최대화를 위한 다층 흡음재-패널 배열 최적설계)

  • Kim, Yong-Jin;Lee, Joong-Seok;Kang, Yeon-June;Kim, Yoon-Young
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.12
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    • pp.1262-1269
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    • 2008
  • Though multilayered foam-panel structures have been widely used to reduce sound transmission in various fields, most of the previous works to design them were conducted by repeated analyses or experiments based on initially given configurations or sequences. Therefore, it was difficult to obtain an optimal sequence of multilayered foam-panel structure yielding superior sound isolation capability. In this work, we propose a new design method to sequence a multi-panel structure lined with a poroelastic material having maximized sound transmission loss. Being formulated as a one-dimensional topology optimization problem fur a given target frequency, the optimal sequencing of panel-poroelastic layers is systematically carried out in an iterative manner. In this method, a panel layer is expressed as a limiting case of a poroelastic layer to facilitate the optimization process. This means that main material properties of a poroelastic material are treated as interpolated functions of design variable. The designed sequences of panel-poroelastic multilayer were shown to be significantly affected by the target frequencies; more panels were obtained at higher target frequency. The sound transmission loss of the system was calculated by the transfer matrix derived from Biot's theory.

Design of Optimal Finline Taper in Multilayered structure with Spectral Domain Immittance Approach

  • Song Seung-Hyun;Cheon Chang-Yul;Hahn Song-Yop;Kim Hyeong-Seok
    • 한국정보통신설비학회:학술대회논문집
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    • 2002.08a
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    • pp.21-23
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    • 2002
  • In millimeter wave applications, it is often necessary to use transitions between waveguide and planar circuits. Finline structures can be used effectively to this purpose. In multilayered case, it is necessary to analyze the structure with numerical method such as spectral domain immittance method. The design procedure uses tile cutoff frequency for each taper width. The dispersion data in a single layer are compared with those in literature. The performance of the designed finline taper is verified with the FEM simulation using HFSS.

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Sintering of LTCC Tape on Alumina Substrates for Multilayered Structure

  • Kim, Hyo-Tae;Nam, Myung-Hwa;Chun, Byung-Joon;Kim, Jong-Hee
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.908-909
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    • 2006
  • The HTCC based multilayer structure plasma head unit have some difficulties in fabrication due to complicated post-processes, such as heat treatment at reduced atmosphere, re-bonding of each layer, and silver metallization. On the other hand, LTCC based technology provides relatively simple process for multilayer plasma unit except weak mechanical properties. To overcome this problem a combined scheme using both LTCC and HTCC technology has been developed in our group, recently. In this work, we report the structural design, materials selection, joining of LTCC with HTCC substrate, and co-firing process for the fabrication of multilayered atmospheric plasma head unit.

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A Design of Multi-layer Planar Type Microwave Filter (다층 평면형 초고주파 필터의 설계)

  • Lee Hong-Seop;Hwang Hee-Yong
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.4 no.1
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    • pp.31-36
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    • 2005
  • In this paper, a planar type bandpass filter in multilayered PCB is presented. The multilayered PCB structure has some advantages on fabricating microwave devices such as the size reduction and ability of tight coupling by folding or embedding. The proposed BPF has two transmission zeros at the both sides of the center frequency by using independent electric and magnetic coupling structure. The designed BPF with four layer teflon PCBs of dielectric constant 2.94 has dimensions of 24x20x1.524 in mm, center frequency of 2.47GHz and bandwidth of about l00MHz. A good agrement is achieved between the measured result and the simulated one. The influences of air gaps between the layers are also analyzed and presented.

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Evaluation of the delamination strengths in differently processed practical Ag-stabilized REBCO CC tapes under transverse loading

  • Diaz, Mark A.;Shin, Hyung-Seop;Ha, Hongsoo;Oh, Sang-Soo
    • Progress in Superconductivity and Cryogenics
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    • v.21 no.4
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    • pp.34-38
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    • 2019
  • Multilayered high-temperature superconductor coated conductor (CC) tapes are used in an extensive range of applications and are exposed to many stresses such as hoop stress, radial/transverse tensile stress under large Lorentz forces, and thermal stress while cooling if thermal expansion properties differ. Loads induced transversely at the tape surface inevitably create delamination phenomena in the multilayered CC tapes. Thus, delamination behaviors of CC tapes along the c-axis under transverse loading conditions, which can vary based on manufacturing process and constituent layers, must be characterized for applications. The anvil test method was used to mechanically investigate the delamination characteristics of various commercially available Ag-stabilized CC tapes at room temperature and 77 K, finding superior strength at the latter. The wide variations found depended on tape structure and fabrication technique. Fractographic morphologies of delaminated tapes supported the findings under transverse loading conditions.

An LTCC Linear Delay Filter Design with Interdigital Stripline Structure

  • Hwang, Hee-Yong;Kim, Seok-Jin;Kim, Hyeong-Seok
    • KIEE International Transactions on Electrophysics and Applications
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    • v.4C no.6
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    • pp.300-305
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    • 2004
  • In this paper, new design equations based on the pole-zero analysis for multi-layered interdigital stripline linear group delay bandpass filter with tap input ports are presented. As a design example, a four-pole group delay filter with center frequency of 2.14GHz, bandwidth of 160MHz, and group delay variation of $\pm$0.1nS for LTCC technology or multilayered PCB technology is designed. In the design process, it is not necessary to simulate the entire structure, as the simulation of half structures is sufficient. Good results can be attained after the optimizing process was performed three times using the proposed equations and a commercial EM simulator.