Samuel Charlot

A low cost and hybrid technology for integrating silicon sensors or actuators in polymer microfluidic systems

This paper describes a new technology permitting a hybrid integration of silicon chips in polymer (PDMS and SU8) microfluidic structures. This two-step technology starts with transferring the silicon device onto a rigid substrate (typically PCB) and planarizing it, and then it proceeds with stacking of the polymer-made fluidic network onto the device. The technology is low cost, based on screen printing and lamination, can be applied to treat large surface areas, and is compatible with standard photolithography and vacuum based approaches. We show, as an example, the integration of a thermal sensor inside channels made of PDMS or SU8. The developed structures had no fluid leaks at the Si/polymer interfaces and the electrical circuit was perfectly tightproof.

Low-profile small-size ferrite cores for powerSiP integrated inductors

Ferrite-based micro-inductors integrated on silicon are proposed as potential hybrid integration in low-power medium frequency DC-DC power converters. The inductors are fabricated at wafer level using micromachining and flip chip assembling techniques. The proposed process is based on a sintered ferrite core placed in between thick electroplated copper windings on two silicon substrates. The low profile (110 μm thick) ferrite cores are produced by thermal bonding of two green tape-casted films of 1.2 × 2.6 × 0.2 mm3, then micro-milled to the final dimensions before sintering. This paper presents the magnetic characterization of the sintered ferrite films cut in rectangular shape and sintered at different temperatures. It is concluded that these small dimension cores could be used in the frequency range applications of 5-10 MHz and would potentially allow a high inductance density in a 3D integration process.

3D heterogeneous integration of wireless communicating nano-sensors on flexible substrate

In this communication, the 3D heterogeneous integration of miniaturized communicating modules used for wireless network application is described. These communicating objects present the particularity of being in Nano-scale range. In fact, each object is composed of Nano-sensors, transceivers and E/R antenna. Such investigated ways of Nano-system integration will allow the development of sensor communicating modules which can be inserted and located in areas with access difficulty (in particular in non planar area) or even in inaccessible places. This attractive integration concept is discussed and illustrated here.

Analysis of the three-chip switching cells approach for integrated multiphase power converter combining monolithic and hybrid techniques: Experimental validation on SiC and Si power assembly prototypes

In this paper, the authors present a novel integration approach for multi-phase IGBT module, based on both monolithic and hybrid integration methods. In this proposed “3-chip” approach, the discrete switches are integrated into three generic monolithic multi-pole power chips and assembled with a judicious packaging. This reduces significantly the commutation loop area and so the stray inductance responsible of overshoot voltage and common-mode dv/dt effect. The operating modes of the multi-pole chips were validated in an inverter application by 2D simulations under mixed-mode SentaurusTM. In order to characterize the commutation loop of the 3-chip approach, two prototype power modules with different technologies (Si and SiC dies) have been realized on PCB substrates. The stray inductances were measured using a precision impedance analyzer (frequency analysis). A double-pulse characterization was also performed to illustrate the effect of stray inductance reduction at the turn-off (temporal analysis). For comparison purposes, two “classical” power converters have been also realized and analyzed. According the results, measurements and analytic estimates, the proposed packaging design allows reducing the stray inductance by at least a ratio of two as compared to the classical layout.

VHF/UHF Kapton supported antenna for cubesat applications

This paper addresses an original concept for very low mass planar flexible Kapton supported antenna for cubesat application. In order to illustrate the concept a dual-band VHF/UHF planar cross dipole antenna is presented. This circularly polarized antenna is compatible with the integration requirements for a cubesat mission and demonstrates very good performances in terms of input matching and radiation pattern.

Recent advances in electromagnetic energy harvesting and Wireless Power Transfer for IoT and SHM applications

This paper addresses the recent advances obtained in LAAS-CNRS Toulouse concerning the development of compact, high-efficiency and multiband RF/microwave energy harvesting devices for autonomous wireless sensors. Several topology of rectenna designed for the Structural Health Monitoring of the satellite antenna panels and for Internet of Things application are discussed.

Mixed monolithic-hybrid integration of multiphase power converter: Preliminary evaluation of the 3-chip integration concept

The authors present a 3-chip mixed integration approach that combines monolithic silicon multi-terminal power chips and flip-chip assembly on a printed circuit board (PCB) for the realization of a multiphase power converter. The overall approach allows for taking advantage of the degrees of freedom offered by silicon and PCB technologies with a limited and well-mastered complexity. The multiphase converter is integrated within three multi-terminal chips that are judiciously packaged, using the partial flip-chip, on a PCB board so as to reduce the switching cell stray inductance as well as the impact of voltage variations on the common mode current that flows through the converters PCB. Using Si and SiC dipole MOSFET and diode chips, converters based on the 3-chip approach were realized and compared to the conventional one. The obtained commutation loop inductance value is reduced by at least a factor of two as compared to that of the conventional one.