Abstract: In recent years, the automotive and aerospace industries have brought stringent reliability constraints on power electronic converters because of safety requirements. Today customers of many power electronic products expect up to 20 years (or even longer) of lifetime and they also want to have a "failure free period" and all with focus on the financials. The renewable energy sectors are also following the same tred, and more and more efforts are being devoted to improving power electronic converters to account for reliability with cost-effective and sustainable solutions. This presentation will introduce the recent progress in the reliability aspect study of power electronic converters for power electronic applications with special focus on renewables. It will cover the following contents: the motivations for highly reliable electric energy conversion in renewables; the reliability requirements of typical power electronic systems; failure mechanisms and lifetime models of key power electronic components (e.g., power semiconductor switches, capacitors, and fans); long-term mission profiles in renewable applications and their components; reliability analysis methods for more complicated systems, tools to be applied, and improvement strategies of power electronic converters in their applications. A few case studies will be given.

Abstract: This paper focuses on the hardware aspects of battery management systems (BMS) for electric vehicle and stationary applications. The purpose is giving an overview on existing concepts in state-of-the-art systems and enabling the reader to estimate what has to be considered when designing a BMS for a given application. After a short analysis of general requirements, several possible topologies for battery packs and their consequences for the BMS’ complexity are examined. Four battery packs that were taken from commercially available electric vehicles are shown as examples. Later, implementation aspects regarding measurement of needed physical variables (voltage, current, temperature, etc.) are discussed, as well as balancing issues and strategies. Finally, safety considerations and reliability aspects are investigated.

Abstract: Power cycling test is one of the important tasks to investigate the reliability performance of power device modules in respect to temperature stress. From this, it is able to predict the lifetime of a component in power converters. In this paper, representative power cycling test circuits, measurement circuits of wear-out failure indicators as well as measurement strategies for different power cycling test circuits are discussed in order to provide the current state of knowledge of this topic by organizing and evaluating current literature. In the first section of this paper, the structure of a conventional power device module and its related wear-out failure mechanisms with degradation indicators are discussed. Then, representative power cycling test circuits are introduced. Furthermore, on-state collector–emitter voltage $(V_{{\rm{CE\_ON}}})$ and forward voltage $(V_{F})$ measurement circuits for wear-out condition monitoring of power device modules during power cycling test are presented. Finally, different junction temperature measurement strategies for monitoring of solder joint degradation are explained.

Abstract: Photoactive perovskite semiconductors are highly tunable, with numerous inorganic and organic cations readily incorporated to modify optoelectronic properties. However, despite the importance of device reliability and long service lifetimes, the effects of various cations on the mechanical properties of perovskites are largely overlooked. In this study, the cohesion energy of perovskites containing various cation combinations of methylammonium, formamidinium, cesium, butylammonium, and 5‐aminovaleric acid is reported. A trade‐off is observed between the mechanical integrity and the efficiency of perovskite devices. High efficiency devices exhibit decreased cohesion, which is attributed to reduced grain sizes with the inclusion of additional cations and PbI2 additives. Microindentation hardness testing is performed to estimate the fracture toughness of single‐crystal perovskite, and the results indicated perovskites are inherently fragile, even in the absence of grain boundaries and defects. The devices found to have the highest fracture energies are perovskites infiltrated into a porous TiO2/ZrO2/C triple layer, which provide extrinsic reinforcement and shielding for enhanced mechanical and chemical stability.

Abstract: GaN based high electron mobility transistors (HEMTs) have demonstrated extraordinary features in the applications of high power and high frequency devices. In this paper, we review recent progress in AlGaN/GaN HEMTs, including the following sections. First, challenges in device fabrication and optimizations will be discussed. Then, the latest progress in device fabrication technologies will be presented. Finally, some promising device structures from simulation studies will be discussed.

Abstract: A vertical ferroelectric HfO 2 field effect transistor based on 3-D macaroni NAND architecture is reported for the first time. Up to 2 V memory window was obtained after the application of 100 ns program/erase pulses. Flash-like endurance of 104 cycles is reported and first reliability assessments were performed.

Abstract: Compared to AC microgrids, DC microgrids have the advantage of higher reliability and efficiency and are convenient to connect with various distribution energy resources (DERs). Concentrated in different time-scale control objectives, a multi-level control structure can guarantee that none of the control objectives affect each other. Considering this, an extensive review on the hierarchical structure of the DC microgrid is applied, and two typical control structures are presented in detail: two-level control architecture and three-level control architecture. Furthermore, the primary, secondary, and tertiary control levels are systematically analyzed and classified according to different control objectives. In order to improve the control capability of the primary control level, an energy efficiency improved DC bus voltage control strategy is proposed to increase the energy efficiency and system reliability. Finally, a distributed DC microgrid model is established and simulated in the RT-LAB to verify the effectiveness of the proposed control strategy.

Abstract: This paper presents a comprehensive analysis about bus bar design procedure. Some applications in terms of rated power and shape are investigated regarding their particular requirements and challenges. The dc-link capacitor selection is one of the first and most important steps. It not only dictates the bus bar complexity but also is the key to accomplish a high-power density prototype. Current density and distribution is discussed in this paper based on simulation results. Moreover, the effects of stray inductance and capacitance are explained along with the dc-link capacitors and power semiconductor devices. Simulated results are compared with measurements by a high precision impedance analyzer, which shows the reliability of 3-D modeling-based designs.

Abstract: In many industrial applications, power interruption is not tolerated, and a highly reliable power electronics system is required. In fact, a failure on the power converter penalizes not only the maintenance cost (to repair or change the converter), but also the operational cost, because the service is interrupted. Thus, this article investigates the failure in dc-dc converters, with the aim to identify the most vulnerable devices and discuss solutions for improving the converter's availability.

Abstract: Microthermoelectric modules are of potential use in fields such as energy harvesting, thermal management, thermal imaging and high-spatial-resolution temperature sensing. In particular, microthermoelectric coolers (µ-TECs)—in which the application of an electric current cools the device—can be used to manage heat locally in microelectronic circuits. However, a cost-effective µ-TEC device that is compatible with the modern semiconductor fabrication industry has not yet been developed. Furthermore, the device performance of µ-TECs in terms of transient responses, cycling reliability and cooling stability has not been adequately assessed. Here we report the fabrication of µ-TECs that offer a rapid response time of 1 ms, reliability of up to 10 million cycles and a cooling stability of more than 1 month at constant electric current. The high cooling reliability and stability of our µ-TEC module can be attributed to a design of free-standing top contacts between the thermoelectric legs and metallic bridges, which reduces the thermomechanical stress in the devices. A free-standing top contact design reduces the thermomechanical stress in microthermoelectric coolers, resulting in improved reliability and cooling stability.

Abstract: Development of an industry leading 10nm CMOS process technology with the highest reported drive currents and cell densities involved numerous enabling innovations, judicious choice of design rules, novel features, and most importantly a relentless pursuit of performance-reliability co-optimization. This paper reports that Intel's 10nm technology achieved scaling benefit over its preceding 14nm generation at matched or better transistor reliability. An elaborate study of the challenges to scaling is presented, which once addressed, enabled meeting aggressive technology reliability targets.

Abstract: Wireless networks for industrial control systems are promising because of their reduced cost, flexible structure, and improved long-term reliability. However, wireless control systems are vulnerable to probing-free attacks (PFAs), which are not possible in wired control systems. Thus, wireless control systems must be made as secure as wired systems. Physical (PHY)-layer security technology (PHY-Sec) may be a new strategy for securing industrial wireless control systems. Among all PHY-Sec technologies, PHY-layer authentication is the first step for PHYSec in industrial wireless control systems. This article discusses the principles of PHY-Sec, its application to wireless control systems, and potential research directions.

Abstract: Perfect power system voltage stability is not possible in practice Generally, the power grid is continually exposed to changes in its load and operating conditions Therefore, dynamic stability analysis is one the most important and effective elements for greater security, stability and reliability of planning, design, operation and economic aspects of electric power networks This study investigates and reports on the dynamic stability of the power system with a large-scale photovoltaic system (L-S PV) Two different scenarios with centralised PV power plants are considered in the medium voltage level without voltage regulation capabilities Simulation results with these scenarios will show how the voltage instability decreases with the L-S PV based on the bus status, disturbance location, and disturbance duration In addition, the study discusses network terminal voltage, generator's rotor angle, generator's terminal current, generator's reactive power and electrical power output This study is an extension of the earlier published conference paper

Abstract: Electric Power Grid Reliability Evaluation deals with the effective evaluation of the electric power grid and explores the role that this process plays in the planning and designing of the expansion of the power grid. The book is a guide to the theoretical approaches and processes that underpin the electric power grid and reviews the most current and emerging technologies designed to ensure reliability. The authors—noted experts in the field—also present the algorithms that have been developed for analyzing the soundness of the power grid.

Abstract: DC-DC converters are becoming more commonly used in power conversion solutions for energy management purposes, being employed in an ever-increasing range of DC-based applications, such as LED lighting, electric vehicles, energy storage solutions, and consumer electronics (laptops, smartphones, etc.). In this context, efficiency and reliability are critical. The research efforts made in improving reliability of DC-DC converters are still quite narrow and scattered. Moreover, DC-DC converters take the shape of an endless number of topologies, with different functionalities and operation principles, thus complicating the task of improving reliability of all forms of DC-DC converters. Consequently, compiling the information about the main failure modes, corresponding fault diagnostic algorithms and fault tolerance strategies developed so far, in a single document, becomes increasingly necessary. Accordingly, this paper presents an up-to-date review of the recent achievements attained regarding the improvement of availability and reliability of DC-DC converters.

Abstract: Co has elicited a strong interest to replace Cu for future interconnect applications in microelectronic circuits due to its potentially lower resistivity and better reliability at scaled dimensions. Here, we demonstrate Co wires with electrical cross-sectional areas as small as 34 nm2 using a simple subtractive patterning technique. Semiclassical resistivity modeling of the wire resistivity indicates that grain boundary scattering is the dominant contribution for cross-sectional areas of the order of 100 nm2, while the contribution of surface scattering increases drastically below 50 nm2. Furthermore, wafer-level reliability tests of the Co wires show the high fusing current densities and a strong resistance to thermoelectric stress demonstrating the potential for robust reliability. The resistivity and the reliability of the Co wires are comparable with those of Ru wires.

Abstract: As the state-of-the-art voltage-source topology, the modular multilevel converter (MMC) is attractive for various medium- or high-power applications. In MMC, reliability and uninterruptable operation are always seen as primary concerns, which requires the MMC can continue operating even though some of the submodules (SMs) are failed. In this paper, a novel fault-tolerant modulation and control strategy is proposed for MMC in medium voltage applications. Compared with previous works, the proposed strategy provides optimum performances under healthy conditions and minimum performance degradation after SM failures. During healthy conditions, the redundant SMs are fully utilized to decrease SM capacitor voltage for higher reliability and to reduce switching frequency for higher efficiency. While during fault-tolerant operation, by appropriate modification of the modulation and controllers, no extra healthy SMs need to be bypassed and the output voltage harmonics of MMC remain unchanged without causing voltage mismatches. Feasibility and effectiveness of the proposed strategy have been verified by simulations in MATLAB/Simulink software and experiments on a downscaled three-phase MMC prototype.

Abstract: This paper discusses the reliability of a new metallization scheme for 10nm back end of line (BEOL) local interconnect. Electromigration (EM) and time dependent dielectric breakdown (TDDB) on cobalt fill interconnects are investigated. Significant innovation in process manufacturing are delivered to meet the reliability challenges of technology scaling. Electromigration time to failure is observed to be at least four orders of magnitude higher for Co fill interconnects compared to Cu alloy metallurgy. Intrinsic TDDB reliability for Co/low-k ILD meets the expectations and surpasses the capability of Cu/low-k ILD systems with E-field acceleration factor of ∼5 cm/MV using E-model fit. Wafer level stress induced voiding reliability on Co shows superior intrinsic properties with respect to Cu.

Abstract: Voltage-sensorless control has been investigated for voltage source inverters (VSIs) for many years due to the reduced system cost and potentially improved system reliability. The VSI-based resistive-active power filters (R-APFs) are now widely used to prevent the harmonic resonance in power distribution network, for which the voltage sensors are needed in order to obtain the current reference. In this paper, a grid-voltage-sensorless control strategy is proposed for the R-APF with series LC -filter. Unlike the traditional resistance emulation method, this proposed control method reshapes the output impedance of the R-APF at the harmonic frequencies, which is independent of the current reference. A fundamental grid-voltage estimation method is also proposed to control the dc-link voltage. The performance of the proposed control method is verified in both simulations and experiments. The results show good accuracy of the emulated resistance and functionality of the dc-link voltage control. With the proposed method, the cost of the R-APF can also be reduced with potentially improved system reliability.

Abstract: Cycle time forecasting (CTF) is one of the most crucial issues for production planning to keep high delivery reliability in semiconductor wafer fabrication systems (SWFS). This paper proposes a nov...

Abstract: The GaN HEMT is a novel wide bandgap device which could improve the overall efficiency and at the same time shrink the system size. In order to verify the reliability of this promising semiconductor device, new measurement and testing methods have to be developed. In this work, as a general basis for performing reliability tests junction temperature measurement methods for GaN HEMT were investigated. By using suitable temperature measurement method, several power cycling tests were performed on GaN HEMT from three different manufacturers. The main failure mechanism of the GaN HEMT from two manufacturers under power cycling tests is the degradation of solder layer between device and printed circuit board. The main failure mechanism of the devices from the third manufacturer is bond wire lift-off. In GaN the piezoelectric effect is involved in the formation of the 2DEG, and electrical characteristics are sensitive to compressive and tensile stress. The question is whether repetitive deformation leads to new failure mechanisms compared to Si devices.

Abstract: This paper presents an optimized switching strategy to reduce the dc-link ripple current for three-level photovoltaic (PV) inverters. The large electrolytic capacitors are commonly used for the dc link of power electronics applications to stabilize the dc-link voltage. The most important factor of designing the dc-link capacitor is the allowable current ripple. The over-ripple current flowing through the capacitor causes a high heat loss, shortened lifespan, low stability, and reliability. The proposed switching scheme selects voltage vectors and reconfigures dwelling order of the vectors to reduce the capacitor ripple current. This switching method is able to extend the lifetime of the dc-link capacitors by simple software programming. In addition, this switching method reduces the common-mode voltage and leakage current that represent high reliability and safety of the system. The effectiveness of the proposed method is verified with simulations and experimental results.

Abstract: Intel's commitment to the environment continues with a breakthrough technology – Low Temperature Solder for Surface Mounted Devices. In this paper we will introduce the technology and its benefits to PC and electronic device manufacturers. We will also discuss the process, material, design optimization efforts performed in order to ensure Yield, Quality and Reliability goals are met. Manufacturability and mechanical/ thermomechanical solder joint reliability data will be shared to demonstrate the impact of key technical modulators.

Abstract: Strain sensors can distinguish diverse deformations of target objects and have promising application as electronic skins, health monitors, soft robotics, etc. However, most of strain sensors suffer from reliability issue along with small strain‐sensing region due to the slippages of conducting components and the relaxation of their underlying elastomers. Here, a strain sensor with a sandwiched structure (i.e., poly(3,4‐ethylenedioxythiophene): poly(styrenesulfonate) and Ag nanowires (NWs) are embedded into polydimethylsiloxane) via a transfer‐printing technique is reported. The devices not only show a broad sensing region up to 50% strain with improved sensitivity, but also possess a reliable resistance response with recoverable conductance. The work provides a simple transfer‐printing method to make reliable, stretchable, and sensitive strain sensors for their promising implementation.

Abstract: Abstract Establishment of effective cooperation between vehicles and transportation infrastructure improves travel reliability in urban transportation networks. Lack of collaboration, however, exacerbates congestion due mainly to frequent stops at signalized intersections. It is beneficial to develop a control logic that collects basic safety message from approaching connected and autonomous vehicles and guarantees efficient intersection operations with safe and incident free vehicle maneuvers. In this paper, a signal-head-free intersection control logic is formulated into a dynamic programming model that aims to maximize the intersection throughput. A stochastic look-ahead technique is proposed based on Monte Carlo tree search algorithm to determine the near-optimal actions (i.e., acceleration rates) over time to prevent movement conflicts. Our numerical results confirm that the proposed technique can solve the problem efficiently and addresses the consequences of existing traffic signals. The proposed approach, while completely avoids incidents at intersections, significantly reduces travel time (ranging between 59.4% and 83.7% when compared to fixed-time and fully-actuated control strategies) at intersections under various demand patterns.

Abstract: The power command in wind energy conversion systems is subject to wind power fluctuations, which may cause significant thermal cyclings of high-power insulated-gate bipolar transistors and may, consequently, lead to a reduction in lifetime. To address this reliability issue, a model integration is established in MATLAB/Simulink, which includes a doubly fed induction generator (DFIG), an aerodynamic model, a drive train model, and a pitch control system. A detailed model of a three-phase converter is adopted for thermal modeling and lifetime estimation. A low-pass filter is utilized to improve the lifetime consumption of the rotor-side converter control in the active power loop in the DFIG. The simulation results indicate that the resulting reliability performance of the system has been significantly improved. Moreover, the capacity factor has been estimated.

Abstract: 2.5D packages have been widely used in electronics industry for high performance and product miniaturization. As Through-Silicon-Via (TSV) fabrication methods and multi-level assembly technologies get mature, 2.5D packaging becomes reliable and affordable. In this work, board-level life prediction was performed for a 2.5D Field-Programmable Gate Array (FPGA) assembly in both accelerated thermal cycling and power cycling. Finite element models were built and validated by warpage measurement. Solder fatigue life in power cycling was investigated by computational fluid dynamics (CFD) simulation and finite element analysis. Improved life prediction for power cycling was achieved by mapping temperature results from CFD model to finite element model. Parametric studies regarding geometry and material factors were performed including PCB, substrate, thermal interface material (TIM) and lid adhesive, to give design suggestions to improve board-level thermal reliability. Maximum junction temperature of a 2.5D FPGA package is dependent on application scenarios and working environment. It is found that the designed maximum junction temperature and applied heatsink clamping force have considerable influences on board-level reliability.