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Program > TutorialsESREF 2019 TutorialsWithin the frame of ESREF 2019, we offer a series of attractive tutorials on important issues of electronics. Since avionic and aeronautic applications are in focus of this year’s conference, related tutorials deal with reliability and power electronics as well as PCB- and system-related analysis and anamnesis approaches towards root cause finding. Take the opportunity looking beyond the scope of device-related failure analysis by learning from experienced tutorialists from industry and research.
Tutorial 1 : The Future of Reliability TestingJ.W. McPherson, McPherson Reliability Consulting LLC, USAHistorically, reliability physics has focused on developing models for time-to-failure. The time- to-failure models for circuits were generally developed using reliability data gathered from very simple test structures that could be stressed to failure. However, today, with circuits playing a such a critical role in our life-support systems (implantable medical devices, auto safety devices, business and home security systems, etc.) a chip failure is no longer an acceptable option. For example, a paradigm shift in the way we approach reliability testing is needed if were are to fully succeed in autonomous driving vehicles. During this presentation it will be emphasized that we must start to focus on device degradation rates rather than failure rates. Special monitoring circuits can be embed in future chip designs to monitor circuit-level degradation. These relatively small reliability monitoring circuits will analyze (real time) the degradation rate (which is a precursor to failure) and forewarn the user of an impending reliability issue. Using this chip-level degradation analysis approach, the chip user can take corrective actions well in advance of a life-threatening chip failure. This presentation will show how degradation rate analysis is well suited for many of the well-known device-degradation mechanisms: HCI, BTI, EM, SM, etc. Even for a failure mechanism such as TDDB (which often gives little/no forewarning of impending failure), the monitoring circuits can analyze voltage overshoots, local temperature rises, high duty-cycle use conditions, and alert the chip user of an impending TDDB issue. In summary, with relatively small monitoring circuits strategically placed and connected in many locations on the chip, there is no fundamental reason why these monitoring circuits cannot analyze circuit degradation and alert the user of an impending reliability issue. Zero chip failures can go from a goal to reality.
Tutorial 2 : Reliability of Power Electronic PackagingOlaf Wittler, Fraunhofer IZM, GermanyAndreas Middendorf, Fraunhofer IZM, GermanyPower electronics modules and packages are subject to changing requirements. On the one hand automotive electrification requires increasing duty cycles in shorter time. On the other hand energy generation and conversion is being done in different outdoor atmospheres like onshore and offshore wind energy generation. Both application fields show an increased impact from moisture related failure mechanisms. In order to address the trend for more performant and robust packages a range of new technologies enter the market, which need to be evaluated regarding their reliability. The tutorial will give an overview on packaging trends and related solutions to assure reliability for long lifetimes and harsh environments. The topics to be covered are:
Tutorial 3 : Introducing layered dielectrics in solid-state microelectronic devicesMario Lanza, Institute of Functional Nano & Soft Materials, Soochow University, ChinaThe introduction of two-dimensional (2D) layered materials in the structure of microelectronic devices is a promising strategy to enhance and extend their performance. Several 2D layered metallic and semiconducting materials (e.g. graphene and MoS2) have been successfully implemented in different types of devices. However, their interaction with traditional dielectrics (e.g. SiO2, HfO2, Al2O3) is very poor because 2D materials do not have dangling bonds, leading to a highly defective interface. To solve this problem, the most feasible solution is to couple graphene and MoS2 with 2D layered dielectrics, so that they can form a clean van der Waals interface. In this context, h-BN is a 2D layered dielectric (with a direct band gap of ~5.9 eV) in which boron and nitrogen atoms arrange in a sp2 hexagonal lattice by covalent bonding, whereas the layers stick to each other by van der Waals attraction. Given its high in-plane mechanical strength (500 N/m), large thermal conductivity (600 Wm-1K-1), and high chemical stability (up to 1500 ºC in air), h-BN has attracted much attention as dielectric. However, most investigations in this field just analyzed small (<10 µm) and thick (> 10 nm) nanoflakes, and applied the electrical stresses using experimental techniques, such as conductive atomic force microscopy (CAFM). In this talk, I will present the most scalable approaches to synthesize multilayer hexagonal boron nitride (h-BN) dielectric stacks, and I will discuss their reliability when used as dielectric in different electronic devices.
Tutorial 4 : Methodology of soft error expertise applied for the use of embedded electronic devices in natural radiation environmentsLaurent Artola, ONERA, FranceThe effects of the space radiation environment on spacecraft systems and instruments are significant design considerations for space missions. The wide interest in satellite and more recently in nano-satellites and drones is reflected by the rapid decrease in cost of COTS (Components Off The Sheft) embedded systems, such as FPGA (Field Programmable Gate Array). Due to the very limited size of these embedded systems and hence of their batteries and/or solar cells, their maximum power consumption is usually constrained to a few tens of Watts. This tight power budget is mostly dominated by the engine and the radio-frequency (RF) transmissions. Laurent Artola will first discuss on the description of radiation environment, from space down to the ground and the associated radiation effects. The applicative environments of the embedded electronic systems are harsh: (1) space radiation particles, (2) civil artificial radiation environment. These radiation environment are known to induce functional errors in analog and digital devices. Moreover, it has been highlighted that low power systems are more sensitive to radiation than standard power devices. Next, he will present two methodologies of soft error expertise: first to evaluate and size the use of COST components such as a FPGA; second, to help designers to harden specific microelectronics, such an ASICs use for IR detector. Finally, he will present the challenge of reliability induced by radiation in the very large scale interaction roadmap.
Tutorial 5 : Review on failure mechanisms InGaN/GaN MQW LED for public light applicationsYannick Deshayes, IMS University of Bordeaux, France
This tutorial gives an actual overview of sustainability, robustness and reliability of GaN LED devices. The overview deals with low, medium and high power GaN LEDs and detailed the main functional parameters drift to estimate performances of the technology regarding application. Different LEDs are considering and coming from different manufacturer and different years of development: LED type I(2005), II(2010) and type III(2015). GaN-based LEDs often use polymer material as chip coating. The most used polymer coatings are siloxane-based materials such as Poly(Methyl-Phenyl-Silixane) – PMPS – or Poly(DiMethylSiloxane) – PDMS. Although their thermal properties offer great possibilities to justify their integration in optoelectronic devices, pellicular effect may occur. This paper points out a pellicular failure mechanism occurring in different Multi Quantum Wells (MQW) GaN-based LEDs coming from different manufacturer and submitted to active storage. Before ageing, an absorption/reemission fluorescence process has been extracted from some LEDs. By performing fluorescence analysis, we have found out the cause of such mechanism coming from silicone oil (polymer coating). Additional physics-chemical analyses, consisting in 1H NMR (Nuclear Magnetic Resonance) and MALDI-TOF (Matrix Assisted Laser Desorption Ionisation/Time Of Flight) mass spectrometry, have been investigated to work out the origin of the absorption/reemission process. The presence of Low Molecular Weight Molecules (LMWM) playing the role of fluorophor molecules is responsible for it. After ageing, some LEDs have loss from 3%(type III) to 65%(type I) of optical power showing the technological evolution of LED assembly. A combination of electro-optical characterizations and physico-chemical analyses has led to the main failure mechanism extraction that is the molecular change of silicone oil activated by photothermal phenomenon. Such pellicular failure mechanism has been suggested to be linked to polymerization or cross-linking of silicone oil usually present in GaN-based LEDs.
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