24 research outputs found

    Micro-tensile tests on micromachined metal on polymer specimens: elasticity, plasticity and rupture

    Full text link
    This study is focused on the mechanical characterization of materials used in microelectronic and micro- electromechanical systems (MEMS) devices. In order to determine their mechanical parameters, a new deformation bench test with suitable micromachined specimens have been developed. Uniaxial tensile tests were performed on "low cost" specimens, consisting in electroplated thin copper films and structures, deposited on a polimide type substrate. Moreover, a cyclic mechanical actuation via piezoelectric actuators was tested on the same deformation bench. These experiments validate the device for performing dynamic characterization of materials, and reliability studies of different microstructures.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

    SEIS: Insight’s Seismic Experiment for Internal Structure of Mars

    Get PDF
    By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars’ surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking’s Mars seismic monitoring by a factor of ∌ 2500 at 1 Hz and ∌ 200 000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars’ surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of Mw ∌ 3 at 40◩ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution

    Cartographie par diffraction des rayons x à l'échelle du micromÚtre des contraintes intragranulaires et des orientations cristallines d'un film d'or déposé sur une micro-poutre en silisium

    Full text link
    Dans les micro-dispositifs, les contraintes rĂ©siduelles ont accru les risques d'endommagement en cours de fabrication et de dĂ©faillance en service. Ces contraintes d'origine thermomĂ©canique ne sont plus maĂźtrisables par des moyens empiriques et il est donc nĂ©cessaire d'utiliser conjointement des techniques expĂ©rimentales et des mĂ©thodes numĂ©riques afin d'amĂ©liorer la connaissance des interactions mĂ©caniques entre matĂ©riaux prĂ©sents dans ces architectures de dimension micromĂ©trique. L'objet de cet article est de prĂ©senter une des nombreuses applications de la micro-diffraction Ă  l'Ă©tude des contraintes rĂ©siduelles et de la microstructure Ă  l'Ă©chelle du micromĂštre dans des micro-dispositifs. Les rĂ©sultats obtenus dans le cas d'un dĂ©pĂŽt d'or de 0,56 Όm sur une poutre de silicium polycristallin de 20 Όm de large et de 100 Όm de long permettent de valider des mesures et simulations macromĂ©caniques rĂ©alisĂ©es sur les mĂȘmes objets
    corecore