Study of Silicon Carbide Power MOSFETs Behaviour in Out-of-SOA Conditions

The need for efficient conversion and control of electrical power in many application areas has rapidly increased the demand for power devices with better and better performances. In order to go beyond the limit imposed by Silicon devices, there has always been a great interest for new materials. In recent years, Silicon Carbide Power devices, mainly power diodes and MOSFETs, have become commercially available and have begun to replace their Silicon counterpart in many application areas. The reason lays in some superior material properties that allow developing higher efficient power systems. Nevertheless, a wider spread of these devices could not be achieved without a deep analysis of the elements that might affect their reliability. The current work deals with the study of SiC Power MOSFETs reliability, with particular focus on short-circuit operation. To achieve this purpose, wide set of experiments has been carried out on commercially available devices, providing both electrical and thermal characterization. Alongside experimental evidences, TCAD simulations have been used to get a full understanding of the inner physical failure dynamics. Eventually, it has been possible to give explanation about SiC Power MOSFETs failure mechanisms. In particular, two different phenomena might occur and both are related to temperature increase inside the device

Influence of design parameters on the short-circuit ruggedness of SiC Power MOSFETs

This work aims to present an investigation on short-circuit (SC) failure behaviour of SiC Power MOSFETs due to the onset of thermal runaway. As inferable from experimental outcomes, it is related to the formation of hotspot, whose exact location is mainly unpredictable and dictated by device structure and design parameters non-uniformities. TCAD simulations were performed to examine the impact of some parameters mismatch on hotspot formation and failure occurrenc

Advanced OoA and automated technologies for the manufacturing of a composite outer wing box

International audienceThis work resumes the results achieved until today in the European project AirGreen 2 of Clean Sky 2 programme, deriving from the application of two different dry preforming processes for the manufacturing of a composite outer wing box of the next generation turboprop aircrafts. Liquid Resin Infusion and Out of Autoclave techniques, by Hand-Layup and Automated Fiber Placement, are considered. The optimisation and validation of the manufacturing processes have been done according to key performance indexes: weight and cost reduction, lower energy consumption, high productivity and minimal reworking time, less intensive labour, minimal scrap and less waste of materials. The work has been performed through manufacturing tests and optimisation of the process parameters, implementation of several bagging techniques, numerical simulations of the infusion process and material characterization tests in operative conditions, from coupons level up to details and elements level (flat stiffened panels). Pro and cons, suggestions and technical considerations useful for the next step of the project (final manufacturing of large parts and components) are assessed

A comprehensive study of the short-circuit ruggedness of silicon carbide power MOSFETs

The behavior of Silicon Carbide Power MOSFETs under stressful short circuit conditions is investigated in this paper. Illustration of two different short-circuit failure phenomena for Silicon Carbide Power MOSFETs are thoroughly reported. Experimental evidences and TCAD electro-thermal simulations are exploited to describe and discriminate the failure sources. Physical causes are finally investigated and explained by means of properly calibrated numerical investigations, and are reported along with their effects on devices short-circuit capability

Transient out-of-SOA robustness of SiC power MOSFETs

Beyond their main function of high-frequency switches in modulated power converters, solid-state power devices are required in many application domains to also ensure robustness against a number of overload operational conditions. This paper considers the specific case of 1200 V SiC power MOSFETs and analyses their performance under three main transient regimes at the edge of and out of their Safe Operating Area: unclamped inductive switching led avalanche breakdown; short-circuit; operation as current limiting and regulating devices. The results presented highlight both inherent major strengths of SiC over Si and areas for improvement by tailored device design. The paper aims to contribute useful indications for technology development in future device generations to better match widespread and varied application requirements

Amphibians of the Aurunci Mountains (Latium, Central Italy). Checklist and conservation guidelines

The Aurunci Mounts are among the less investigated areas of Latium for herpetological researches. In this study we surveyed 72 potential breeding sites of amphibians within the Monti Aurunci Regional Park. Fifty-eight spawning sites, and nine amphibian species (64.3% out the 14 amphibian species living in Latium region) have been found. Green toad and European tree frog were recorded for the first time for the Aurunci Mounts. Reproductive activity was recorded for Salamandrina perspicillata, Triturus carnifex, Lissotriton vulgaris, Lissotriton italicus, Bufo bufo, Pseudopidalea viridis, Hyla intermedia, Rana italica and Rana synklepton hispanica. Unexpectedly, no amphibian species has been recorded within the Monte Redentore (pSIC IT6040027), despite this site was included within the Natura 2000 network also basing on the presence of Triturus carnifex

A comprehensive study on the avalanche breakdown robustness of silicon carbide power MOSFETs

This paper presents an in-depth investigation into the avalanche breakdown robustness of commercial state-of-the-art silicon carbide (SiC) power MOSFETs comprising of functional as well as structural characterization and the corresponding underlying physical mechanisms responsible for device failure. One aspect of robustness for power MOSFETs is determined by its ability to withstand energy during avalanche breakdown. Avalanche energy (EAV) is an important figure of merit for all applications requiring load dumping and/or to benefit from snubber-less converter design. 2D TCAD electro-thermal simulations were performed to get important insight into the failure mechanism of SiC power MOSFETs during avalanche breakdow

ブンカ シュウカン テキ サイオ ウメル コミュニティ ツウヤク トハ

This paper investigates the failure mechanism of SiC power MOSFETs during avalanche breakdown under unclamped inductive switching (UIS) test regime. Switches deployed within motor drive applications could experience undesired avalanche breakdown events. Therefore, avalanche ruggedness is an important feature of power devices enabling snubber-less converter design and is also a desired feature in certain applications such as automotive. It is essential to thoroughly characterize SiC power MOSFETs for better understanding of their robustness and more importantly of their corresponding underling physical mechanisms responsible for failure in order to inform device design and technology evolution. Experimental results during UIS at failure and 2D TCAD simulation results are presented in this study