Modeling and numerical study of the influence of imperfect interface properties on the reflection coefficient for isotropic multilayered structures.

International audienceThe microelectronics industry is expressing an increased demand for the development of non-destructive tools and methods for health control and diagnostics in multilayered structures. The purpose of these tools is to detect problems such as delaminations, inclusions and microcracks. The aim of this paper is to study the effect of imperfect interfaces on the wave propagation in multilayered structures. This type of structure represents the typical architecture of many microelectronic components. This study will be based on the calculation of the reflection coefficient and the guided waves dispersion curves. The investigated structure is an isotropic trilayer where two metallic layers are bonded together by an adhesive layer made of an epoxy resin. Comparisons were performed in order to evaluate numerically the influence of several properties of the adhesive layer on the guided waves behavior. In addition, an imperfect viscoelastic interface layer model [1] has been implemented in order to simulate different adherence qualities between the metallic layers

High resolution B-Scan imaging of the skin using a 50 MHz P(VDF-TrFE) Transducer

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A Novel Design of Surface Acoustic Wave Device: Towards Sensor Sensitivity Enhancement

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Acoustoelectric effect in piezocomposite sensors

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Impédance acoustique d'un liquide à la surface d'un quartz coupe AT

The Shear acoustic impedance of a liquid can be determined from the complex reflection coefficient of the acoustic wave incident on the AT-cut quartz/liquid interface. This complex acoustic coefficient is related to the down shift of the resonant frequency as well as the decrease of the quality factor, due to the liquid load. The effective acoustic impedance measured with the thickness shear mode resonator is shown to be composed of three main components : a preponderant complex component due to viscous coupling between the quartz and the liquid, a pure imaginary additional component due to liquid trapped in the surface irregularities and a pure real additional component due to compressional wave generation in the bulk liquid

Transducteurs ultrasonores miniatures haute fréquence : application à l'imagerie des structures superficielles de la peau et de l'oeil

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Characterisation of P(VDF-TrFE) material taking into account dielectric relaxation: application to modelling of high frequency transducers

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