Properties and Application of Geopolymers Vol. 841 (/MSF.841 /book) Development and Investigation of Materials Using Modern Techniques Vol. 840 (/MSF.840/book) Superplasticity in Advanced Materials ICSAM 2015 Vols. 838-839 (/MSF.838-839/book) 12th International Conference on High Speed Machining Vols. 836-837 (/MSF.836-837/book) Sintering Fundamentals II Vol. 835 (/MSF.835/book) Advanced Machining Technologies: Traditions and Innovations Vol. 834 (/MSF.834/book) Applied Materials and Technologies Vol. 833 (/MSF.833/book) Emerging Functional Materials: Book (/MSF.841/book) Papers (/MSF.841)

Materials Science Forum

Mechanical properties of nano-silver joints as die attach materials

The microbial fuel cell (MFC) technology offers sustainable solutions for distributed power systems and energy positive wastewater treatment, but the generation of practically usable power from MFCs remains a major challenge for system scale up and application. Commonly used external resistors will not harvest any usable energy, so energy-harvesting circuits are needed for real world applications. This review summarizes, explains, and discusses the different energy harvesting methods, components, and systems that can extract and condition the MFC energy for direct utilization. This study aims to assist environmental scientists and engineers to gain fundamental understandings of these electronic systems and algorithms, and it also offers research directions and insights on how to overcome the barriers, so the technology can be further advanced and applied in larger scale.

Practical Energy Harvesting for Microbial Fuel Cells: A Review

In order to take the full advantage of the high-temperature SiC and GaN operating devices, package materials able to withstand high-temperature storage and large thermal cycles have been investigated. The temperature under consideration here are higher than 200 °C. Such temperatures are required for several potential applications such as down-hole oil and gas industry for well logging, aircrafts, automotive, and space exploration. This review focuses on the reliability of a selection of potential components or materials used in the package assembly as the substrates, the die attaches, the interconnections, and the encapsulation materials. It reveals that, substrates with low coefficient of thermal expansion (CTE) conductors or with higher fracture resistant ceramics are potential candidates for high temperatures. Die attaches and interconnections reliable solutions are also available with the use of compatible metallization schemes. At this level, the reliability can also be improved by reducing the CTE mismatch between assembled materials. The encapsulation remains the most limiting packaging component since hard materials present thermomechanical reliability issues, while soft materials have low degradation temperatures. The review allows identifying reliable components and materials for high-temperature wide bandgap semiconductors and is expected to be very useful for researchers working for the development on high-temperature electronics.

Survey of High-Temperature Reliability of Power Electronics Packaging Components

Silver (Ag) has been under development for use as interconnect material for power electronics packaging since the late 1980s. Despite its long development history, high thermal and electrical conductivities, and lead-free composition, sintered Ag technology has limited market penetration. This review sets out to explore what is required to make this technology more viable. This review also covers the origin of sintered Ag, the different types and application methods of sintered Ag pastes and laminates, and the long-term reliability of sintered Ag joints. Sintered Ag pastes are classified according to whether pressure is required for sintering and further classified according to their filler sizes. This review discusses the main methods of applying Ag pastes/laminates as die-attach materials and the related processing conditions. The long-term reliability of sintered Ag joints depends on the density of the sintered joint, selection of metallization or plating schemes, types of substrates, substrate roughness, formulation of Ag pastes/laminates, joint configurations (i.e., joint thicknesses and die sizes), and testing conditions. This paper identifies four challenges that must be overcome for the proliferation of sintered Ag technology: changes in materials formulation, the successful navigation of the complex patent landscape, the availability of production and inspection equipment, and the health concerns of Ag nanoparticles. This paper is expected to be useful to materials suppliers and semiconductor companies that are considering this technology for their future packages.

/pdf/are-sintered-silver-joints-ready-for-use-as-interconnect-2rnz0z0bm7.pdf

Are Sintered Silver Joints Ready for Use as Interconnect Material in Microelectronic Packaging

High temperature power electronics has become possible with the recent availability of silicon carbide devices. This material, as other wide-bandgap semiconductors, can operate at temperatures above 500 °C, whereas silicon is limited to 150-200 °C. Applications such as transportation or a deep oil and gas wells drilling can benefit. A few converters operating above 200 °C have been demonstrated, but work is still ongoing to design and build a power system able to operate in harsh environment (high temperature and deep thermal cycling).

/pdf/state-of-the-art-of-high-temperature-power-electronics-3qyx36fnso.pdf

State of the art of high temperature power electronics

Electrical energy generation from a large number of microbial fuel cells operating at maximum power point electrical load

In view of their potential for high dielectric breakdown strengths, low dissipation factors, and good dielectric stability over a wide range of frequencies and temperature, metallized films capacitors are very used components for aeronautic applications Nevertheless, capacitors remain unreliable components; a good acquaintance of their deterioration over time would enable us to perform a predictive maintenance on the component and thus improve the availability of the whole system This operation requires the knowledge of the capacitor ageing law and their failure mechanisms associated with the application In a standard six pulses rectifier-fed pulse width modulation inverter, dc-link capacitors are generally subjected to gradients of temperature due to the encountered electrical stresses Since traditional floating ageing tests, which consist on applying constant voltages and temperature across the component, do not reflect the normal ageing of the component, we propose in this paper to study the degradation kinetics of metallized films capacitors under high ripple currents, alone or combined with a dc voltage across the devices terminals It will therefore reproduce with a more representative way the ageing of the component in comparison with the traditional floating ageing tests Based on the resonant circuit properties, the ageing test bench especially developed for our study provides high currents and voltages from a low power source Through the study and analysis of the capacitors parameters evolution under high ripple currents, an original ageing law is proposed to model the capacitance decrease with time based on the electrochemical corrosion of the capacitors electrodes The adequacy between the experimental points and the model proved the validity of the proposed law

Accelerated Ageing of Metallized Film Capacitors Under High Ripple Currents Combined With a DC Voltage

https://hal.archives-ouvertes.fr/hal-00874458/document

Migration issues in sintered-silver die attaches operating at high temperature

In this paper, the authors propose a solution to provide self protection in a normally-On JFET voltage fed inverter. The solution is a plug-in to an existing Gate driver. An overview of JFET Gate driving serves as an introduction to the problem of self protection of inverters using Normally-On devices.

Pascal Bevilacqua

Papers

State of the art of high temperature power electronics

Electrical energy generation from a large number of microbial fuel cells operating at maximum power point electrical load

Accelerated Ageing of Metallized Film Capacitors Under High Ripple Currents Combined With a DC Voltage

Migration issues in sintered-silver die attaches operating at high temperature

Normally-On SiC JFETs in power converters: Gate driver and safe operation