Understanding of wet and alternative particle removal processes in microelectronics: theoretical capabilities and limitations, Journal of Telecommunications and Information Technology, 2005, nr 1

A 2 orders of magnitude range of van der Waals interactions is considered here to take the majority of the variety of shapes and materials of actual particles into account. Comparing these interactions with the repulsive forces generated by electrostatic charges, drag, surface tension, shock waves, high accelerations and aerosol particles, the intrinsic capabilities and limitations of the different cleaning processes can be predicted. Three kinds of particle-removal processes have been identified { universal processes capable of removing all particle sizes and types, even from patterned wafers, processes that present the same theoretical ability but are actually limited by the accessibility of the particles, and finally cleanings that are not able to remove all particle sizes

Accelerated aging test of solar reflectors according to the new AENOR standard – results of a round Robin test

Durability tests of reflector materials for concentrating solar applications are crucial to guarantee the profitability of the plants and to ensure a proper efficiency during their lifetime. A standard including a set of five accelerated aging tests is close to be published by the Spanish standardization entity AENOR, within the sub-committee AEN/CTN 206/SC117. Under the framework of the STAGE-STE project, a Round Robin Test was organized by six partners to evaluate the comparability of results obtained in their respective laboratories after performing these durability tests. According to the results, in general a good agreement among the partners was found, with negligible to slight reflectance losses. In addition, it was noticed that the reference standard used in the reflectance measurements is of high importance. The conclusions of this work will help to improve the standard in future versions.The research leading to this work has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 609837 (STAGE-STE). The authors would like to thank the participants of the working group for solar reflectors of WG 2 of the Spanish sub-committee AEN/CTN 206/SC 117

A comparative study of non-covalent encapsulation methods for organic dyes into silica nanoparticles

Numerous luminophores may be encapsulated into silica nanoparticles (< 100 nm) using the reverse microemulsion process. Nevertheless, the behaviour and effect of such luminescent molecules appear to have been much less studied and may possibly prevent the encapsulation process from occurring. Such nanospheres represent attractive nanoplatforms for the development of biotargeted biocompatible luminescent tracers. Physical and chemical properties of the encapsulated molecules may be affected by the nanomatrix. This study examines the synthesis of different types of dispersed silica nanoparticles, the ability of the selected luminophores towards incorporation into the silica matrix of those nanoobjects as well as the photophysical properties of the produced dye-doped silica nanoparticles. The nanoparticles present mean diameters between 40 and 60 nm as shown by TEM analysis. Mainly, the photophysical characteristics of the dyes are retained upon their encapsulation into the silica matrix, leading to fluorescent silica nanoparticles. This feature article surveys recent research progress on the fabrication strategies of these dye-doped silica nanoparticles

Etude des mécanismes de collage des microsystèmes lors de la phase de libération. Mise en oeuvre de moyens de prévention

Microsystems are components manufactured starting from the processes of microelectronics and which gather on the same substrate of the electronic, mechanical, optical, chemical or biological functions. Their geometrical characteristics make them extremely sensitive to the forces surfaces which can lead to their adhesion, in particular during the release step. This thesis relates to the comprehension of this phenomenon. For that a measurement of the forces of adhesions between two silicon surfaces in liquid medium was undertaken using a surface force apparatus and using microstructures. Impact of the surface tension of various liquids on adhesion was studied. The study of the rugosification of silicon by wet etching, characterized by atomic force microsopy ; and the impact of surface roughness on adhesion was also carried out. Lastly, an original industrial process of wet release without dewetting substrates was developed.Les microsystèmes regroupent sur un même substrat des fonctions électroniques, mécaniques, optiques, chimiques ou biologiques et sont fabriqués par les procédés de la microélectronique. Leurs particularités géométriques les rendent extrêmement sensibles aux forces de surfaces qui peuvent conduire à leur collage définitif, notamment lors de l'étape de libération. Cette thèse porte sur la compréhension de ce phénomène. Pour cela une mesure des forces d'adh´esions entre deux surfaces de silicium en milieu liquide a été entreprise à l'aide d'un appareil de mesure des forces de surface et à l'aide de microstructures. L'impact de la tension de surface de différents liquides sur l'adhésion a été étudié. L'étude de la rugosification du silicium par gravure humide, caractérisée par microscope à force atomique ; et l'impact cette rugosité sur l'adhésion a également été menée. Enfin, un procédé industriel original de libération par voie humide sans démouillage des substrats a été développé

Etude des mécanismes de collage des microsystèmes lors de la phase de libération (Mise en oeuvre de moyens de prévention)

AIX-MARSEILLE2-BU Sci.Luminy (130552106) / SudocSudocFranceF

Does micro-scaling of CPV modules improve efficiency? A cell-to-module performance analysis

International audienc

Stress factors identification and Risk Probabilistic Number (RPN) analysis of Li-ionbatteries based on worldwide electric vehicles usage

International audienceHaving clear insights of the stress factors that the electric vehicle (EV) batteriesencounter during their service lifetime is crucial for more reliable ageing testing andmodelling. Since the first deployment of Li-ion battery based EV, numerous drivingcampaigns with field data were published. The goal of this article is to gather, assessand analyse them in order to quantify the stress factors depending on the EV type. Thetargeted stress factors are the temperature of the cells, the discharging and chargingrates, as well as the SOC ranges. 228 million km of driving and 7.8 million trips worthof data for over 37,000 EV were investigated. Along with this literature enquiry, datafrom an EV in which cells' temperature was monitored for driving, charging andparking conditions, complemented the analysis. For each stress factor, results werecollected, homogenised and compared with each other in order to draw conclusions.Finally, a Risk Probabilistic Number (RPN) was used to evaluate the stress factors withrespect to their impact on the ageing of Li-ion batteries, considering a central Europeanweather. The most critical stress factors for BEV cells are cycling at high mid-SOCregions and high SOC idle times. Concerning HEV cells, high power cycling at mid-SOC regions is the most critical stress, and no stresses were identified during idletimes. PHEV cells' most critical stress factors are large DOD cycling and highcharge/discharge power. Mild and low temperatures are found to be the most commonin such weathers. The RPN analysis serves as a guide for parametrizing and designingreliable accelerated ageing testing on Li-ion batteries depending on their application

Results and Analysis of a BEV Driving Campaign Comprising Three Types of Daily Uses Categorized by Home-to-Work Distance

International audienceIn this poster, the results, analyses and observations obtained from a driving campaign are going to be exposed. 24 drivers volunteered to use a monitored commercial BEV for home-to-work trips during two weeks each. They were divided into three kinds of profiles depending on the distance from their homes: short (<10km), medium (10 to 20km) and long (20 to 40km). Along with the electrical and GPS measurements, the BEV was implemented with thermocouples over the entire architecture of the battery pack and temperature measurements were taken during driving, charging and parking

Review of accelerated ageing test modelling and its application to solar mirrors

International audienceSolar mirrors for concentrated solar power (CSP) plants are expected to last at least 30 years. As this delay is far too long to obtain useful information regarding in-service degradation, accelerated approaches to weathering testing are performed by manufacturers and research laboratories in order to quickly assess the lifetime of commercial or new technologies. However, most published studies that have been performed in the CSP field are based on phenomenological approaches. The characterization of the degradation, which mostly considers reflectance loss, has rarely been linked to physical or chemical processes that are responsible for the degradation of properties. Furthermore, the general laws that can be established from these data to establish material behaviour are empirical.Ageing tests have been used for many years in other fields, particularly in the domain of polymeric materials. The impacts on the material properties of stress factors such as temperature, irradiation and humidity have been extensively studied, and models have been proposed for different kinds of materials, even though most are based on empirical observations. One of the goals of this article is to determine how these models could be applied to the weathering of solar mirrors, and as such, the goal of this paper is to provide a critical review of the various models that are most used and accepted by the scientific community. All of these models include material-dependent parameters, and the values that have been determined in these studies are reported here to list their order of magnitude