Publications by Sonia Vionnet Menot

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Thick film deposition of conductive, dielectric and resistive pastes on ceramic membranes is a cost effective technique to manufacture piezoresistive pressure sensors. Thick-film resistors consist of a percolating network of conductive oxide nanoparticles dispersed in an insulating glassy matrix, the electrical properties of which depend on firing conditions and composition. Ceramic membranes are appropriate to withstand the firing temperatures of thick-film materials, which are about 850°C. However brittle

Thick-film materials are very advantageous for piezoresistive pressure and force sensors because of ease of processing, reliability and low cost. However, their applications are restricted because standard thick-film materials require processing temperatures around 850°C, which essentially restricts them to ceramic substrates. In this work, we examine the processing and properties of thick-film dielectric and resistor compositions designed to sinter at lower temperatures, making them compatible with high-st

Thick-film technology has found applications on miniaturised hybrid circuits in various fields (automotive electronics, televisions, ...). This technology is also now widely used for the fabrication of force and pressure sensors that use the piezoresistive ...

In this work, a set of low-temperature thick-film dielectrics consisting of two high-lead low-temperature glasses, stabilised by various amounts of alumina filler, is characterised on alumina and aluminium metal, as a function of firing temperature. Corres ...

The piezoresistive effect of thick-film resistors has found widespread application in pressure and force sensors due to their high strain-sensitivity, stability and low-cost. The main material requirements for these applications are a high piezoresistive response, low noise and low temperature dependence. However, many useful elastic substrate materials are degraded at the standard thick-film processing temperature of 850 °C, and therefore require a lower one. This is achieved by engineering the glass compo

In this work, a novel low-temperature thick-film system (dielectrics, resistors and conductors) is characterised for application on substrates, which cannot be exposed to the standard high-temperature 850 C thick-film firing cycle. Aluminium alloy sheets are ideal substrate materials for high power electronics, due to their excellent thermal dissipation, mechanical sturdiness, easy packaging and adjustable thermal expansion coefficient (Al-Si system). In addition to standard hybrid electronics, potential ap

In this work, we aim to understand the firing behaviour of three representative thick-film resistor compositions used in force and pressure sensors. The dependence of the materials' microstructure and properties (sheet resistance and its temperature coefficient, gauge factor) is studied as a function of firing temperature and time, and cooling rate (furnace or quench). The stability of the properties is assessed by annealing at intermediate temperatures (100 and 250 °C). Microscopic and structural analysis

In this work, we have modified a low-temperature thick-film system previously developed for aluminium and aluminium alloy substrates in order to adapt it to ferritic and austenitic stainless steel, and glass substrates, which, unlike the common alumina substrate material, cannot usually be exposed to the standard high-temperature 850 °C thick-film firing cycle. Such substrate materials are useful for several important applications: high-response piezoresistive thick-film sensors (steel), displays (glass), h

A vast class of disordered conducting-insulating compounds close to the percolation threshold is characterized by nonuniversal values of transport critical exponent t, in disagreement with the standard theory of percolation which predicts t ...

A vast class of disordered conducting-insulating compounds close to the percolation threshold is characterized by nonuniversal values of transport critical exponents. The lack of universality implies that critical indexes may depend on material properties such as microstructure, composition etc., and that in principle they can be influenced by suitable applied perturbations leading to important informations about the origin of nonuniversality. Here we show that RuO2-glass compounds can have nonuniversal val

Thick-film resistors (TFRs) consist of a percolating network of conducting oxide nanoparticlesdispersed in an insulating glassy matrix, whose resistive properties are dominated by quantumtunneling across insulating layers separating adjacent conducting grains. Tunneling processes are at the origin of the high sensitivity of the TFRs resistances to applied strains. We have measuredtransport and piezoresistive response for different RuO2-based TFRs as a function of metallic concentration x and RuO 2 grain siz

In this work, a low-temperature thick-film dielectric consisting of a high-lead low-temperature glass with a reactive nanoscale filler is characterised to enable deposition of thick-film electronics onto substrates such as glass and metals (steel, aluminium, brass, titanium) which cannot be exposed to the standard high-temperature 850 C thick-film firing cycle. The dielectric is stabilised by reaction of the filler with the lead in the glass. For a TiO2 filler, we get : PbO (glass) + TiO2 (filler) -> PbTiO3

In this work, the properties (sheet-resistance, temperature coefficient and piezoresistance / gauge factor) and stability of thick-film resistors with low firing temperatures (525...650°C) are studied. To this end, two low-melting lead borosilicate glass composition have been chosen, together with RuO2 as a conductive filler. The effect on the properties and stability of composition and firing temperature is studied. The stability of the materials is quantified during high-temperature storage (annealing) at

We show that in RuO2–glass composites the nonuniversal resistivity exponent can be modulated by an applied mechanical strain, signaled by a logarithmic divergence of the piezoresistive response at the percolation threshold. We interpret this phenomenon as being due to a tunneling-distance dependence of the transport exponent, supporting therefore a theory of transport nonuniversality proposed some years ago. © 2004 American Institute of Physics. [DOI: 10.1063/1.1835996]

Analyse des diélectriques commerciaux : fluorescence X, Infrared absorption, EDX, X-ray Diffraction. Détermination des éléments, déduction des composés par détermination des phases de ceux ci. Tout ceci afin de déterminer les éléments responsables de l’adhérence des TF sur acier et titane.

This paper presents recent work on complete thick-film systems, including dielectrics, conductors and resistors, with a lowered firing temperature range of 450...750°C. These materials allow the extension of proven, reliable and inexpensive thick-film technology to novel applications in electronics and sensors.

L’IPM développe des capteurs de pressions piézorésistifs basés sur la technologie hybride (couches épaisses) sur céramique. Le projet consiste à réaliser des prototypes de tels capteurs de forces formés par un assemblage de deux structures en alumine soudées entre elles par une brasure tendre. Le but final de cette étude est d’atteindre une bonne résistance mécanique du capteur, couplée à une stabilité au fluage et au cyclage thermique. Il s’agit donc d’optimiser la stabilité de ce type d’assemblage par bra

Project aim: optimised piezoresistive thick-film compositions, especially for low-temperature applications on aluminum alloys, titanium alloys, steel and glass

Sonia Vionnet Menot

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Development of pressure sensors by powder technology

Development of low-temperature thick-film materials for piezoresistive sensors

Low firing temperature thick-film piezoresistive composites : properties and conduction mechanism

Low-temperature thick-film dielectrics and resistors for metal substrates

Study of electrical properties of piezoresistive pastes and determination of the electrical transport

Effect of composition and microstructure on the transport and piezoresistive properties of thick-film resistors

Integrated thick-film hybrid microelectronics on aluminium substrates

Firing, quenching and annealing studies on thick-film resistors

Properties and stability of thick-film resistors with low processing temperatures - effect of composition and processing parameters

Integrated thick-film hybrid microelectronics applied on different material substrates

Tunneling-percolation origin of nonuniversality: Theory and experiments

Strain dependence of transport critical exponent in RuO2-glass systems

Transport nonuniversality and critical behavior of the piezoresistive response in thick-film resistors

Low-temperature thick-film dielectrics stabilised by reaction with a nanocrystalline powder

Properties and stability of thick-film resistors with low processing temperatures - effect of composition and processing parameters

Strain modulation of transport criticality in RuO2-based thick-film resistors

Analyse FX des diélectriques commerciaux [XRF analysis of commercial dielectrics]

Low-temperature thick-film systems for electronic and sensor applications

Qualification de capteurs amplifiés : Tests en charge et en température (alumine sur alumine)

Nano grain thick-film pastes for mechanical sensor applications