232,131 research outputs found

    Soft, thermally conductive material

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    Silicon rubber filled with high percentage of silver-plated copper microspheres provides soft, thermally conductive seat for thermal switch. Material also could be used in thin sheet form to prevent corrosion between dissimilar metals while maintaining good thermal communication. It could be used as thermal gasketing

    FEM analysis on the deformation behavior of flange portion during early stage in deep drawing of dúplex embossed sheet metal

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    Duplex embossed sheet metals are very useful due to their high rigidity. Furthermore, it is very interesting that the periodic configurations given by embossing brings a new macroscopic feature into a sheet metal. In this study, in order to confirm the effect of only sub-macroscopic structure, which was the configuration given to sheet metal by duplex embossing process, the material was set to isotropy, and FEM simulation was carried out to investigate about the deformation ehavior of flange portion during the early stage in deep drawing of duplex embossed sheet

    Cross-bidge Kelvin resistor (CBKR) structures for measurement of low contact resistances

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    A convenient test structure for measurement of the specific contact resistance (ρc) of metal-semiconductor junctions is the CBKR structure. During last few decades the parasitic factors which may strongly affect the measurements accuracy for ρc < 10-6 Ω • cm2 have been sufficiently discussed and the minimum of the ρc to be measured using CBKR structures was estimated. We fabricated a set of CBKR structures with different geometries to confirm this limit experimentally. These structures were manufactured for metal-to-metal contacts. It was found that the extracted CBKR values were determined by dimensions of the two-metal stack in the contact area and sheet resistances of the metals used. \ud Index Terms—Contact resistance, cross-bridge Kelvin resistor (CBKR), sheet resistance, test structures, metal, silico

    Fermi surfaces of single layer dielectrics on transition metals

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    Single sheets of hexagonal boron nitride on transition metals provide a model system for single layer dielectrics. The progress in the understanding of h-BN layers on transition metals of the last 10 years are shortly reviewed. Particular emphasis lies on the boron nitride nanomesh on Rh(111), which is a corrugated single sheet of h-BN, where the corrugation imposes strong lateral electric fields. Fermi surface maps of h-BN/Rh(111) and Rh(111) are compared. A h-BN layer on Rh(111) introduces no new bands at the Fermi energy, which is expected for an insulator. The lateral electric fields of h-BN nanomesh violate the conservation law for parallel momentum in photoemission and smear out the momentum distribution curves on the Fermi surface.Comment: 14 pages, 6 figures, 1 table, 1 equation, Accepted for publication in the Special Surface Science issue in honor of Gerhard Ertl's Nobel Priz

    Process and machine system development for the forming of miniature/micro sheet metal products

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    This paper reports on the current development of the process for the forming of thin sheet-metal micro-parts (t < 50µm) and the corresponding machine system which is part of the research and technological development of an EU funded integrated project - MASMICRO ("Integration of Manufacturing Systems for the Mass-Manufacture of Miniature/Micro-Products" (/www.masmicro.net/). The process development started with qualification of the fundamentals related to the forming of thin sheet-metals in industrial environment, for which a testing machine and several sets of the testing tools were developed. The process was further optimised, followed by new tool designs. Based on the experience gained during the process development, a new forming press which is suitable for industrial, mass-customised production, has been designed

    Metallic multilayers for X-band Bragg reflector applications

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    We present a structural and high frequency (8.72GHz) electrical characterization of sputter deposited Ti/W, Ti/Ru and Mo/Ti metallic multilayers for potential application as acoustic Bragg reflectors. We prove that all metallic multilayers comprised of different acoustic impedance metals such as Ti, W, Mo are promising candidates for Bragg reflector/bottom electrode in full X-band thin film acoustic resonators. Values for high frequency resistivity of the order of 108ohm.m10^{-8} ohm.m are measured by use of a contact-free/non-invasive sheet resistance method

    Electrical upsetting of metal sheet forms weld edge

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    Electric gathering of sheet stock edges forms metal sheets in the shape of gore sections with heavier edge areas that can be welded without loss of strength. The edges are gathered by progressive resistance heating and upsetting, and are formed automatically. This process avoids disturbance of the metals internal structure
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