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

In this paper, a novel online technique for the state of health monitoring of supercapacitors energy storage systems is presented. It is based on measuring the equivalent series resistance of the energy storage element representing its aging. The suggested approach uses a suitable balancing circuit connected to the terminal of the storage element in order to extract its actual parameters. This new method is characterized by its simplicity which makes it convenient for industrial applications. A test bench is developed in order to prove the new method’s reliability and accuracy. Experimental results taken from the test bench and from an offline classical laboratory characterization method shows that the differences between both responses do not exceed 7%.

https://hal.archives-ouvertes.fr/hal-01721810/document

Online supercapacitor health monitoring using a balancing circuit

Bi-directional electrical characterisation of microbial fuel cell.

High temperature power electronics has become possible with the recent availability of siliconcarbide devices. This material, as other wide-bandgap semiconductors, can operate at tempera-turesabove500°C,whereassiliconislimitedto150-200°C.Applicationssuchastransportationor a deep oil and gas wells drilling can benet. A few converters operating above 200°C havebeen demonstrated, but work is still ongoing to design and build a power system able to operatein harsh environment (high temperature and deep thermal cycling). 1 Introduction The rst part of this paper will describe some of the most prominent applications for hightemperature power electronics. This is where high temperature-capable converters are enablerfor new solutions, such as electrical actuators for jet engine.The second part will give a short explanation on why wide-bandgap semiconductors areneeded for high-temperature electronics, and why, among them, silicon carbide has been cho-sen.Finally, we will see that a lot of work is still required to design a complete power converter(this include passive components, packaging, control circuits in addition to the active powerdevices).

https://hal.archives-ouvertes.fr/hal-00413349/document

State of the art of High Temperature Power Electronics

This paper presents the design and fabrication of micro-planar inductors with one and two magnetic layers, as well as the corresponding experimental results. Spiral inductors are suitable for low power (1 W) DC-DC monolithic converters. Sufficiently high switching frequency (>100 MHz) enables a System-In-Package assembly with the micro-planar inductors that could be used as a carrier of the active chip. Thick magnetic layers serve as a mechanical carrier and also present a double purpose of increasing the inductance value and absorbing electromagnetic interferences (EMI). Geometrical parameters are studied using an electromagnetic simulator for optimization purposes. A 500 nH spiral inductor with expected 140m RDC, 9mm2 footprint area is designed for operating at 100 MHz. A low-cost, labscale technology that is compatible with industrial clean rooms has been developed. Samples are tested using a LCR meter in the 10 kHz to 110MHz frequency range. The performances of the micro-inductors are compared to the predicted response of simulated equivalent model with good agreement.

Planar, Double-Layer Magnetic Inductors for Low Power, High Frequency DC-DC Converters

The behavior of 4H-SiC power devices in severe environment with varying temperature is a key characteristic indicating their reliability. This paper shows the dependence of the ionization rates of 4H-SiC with respect to temperature. Optical Beam Induced Current (OBIC) measurements have been performed on PN junctions to determine the multiplication coefficient for temperature varying between 100 and 450K. That allows extracting the ionization rates by fitting the curves of multiplication coefficient.

/pdf/temperature-dependence-of-4h-sic-ionization-rates-using-4lpbb9kg1d.pdf

Pascal Bevilacqua

Papers

Online supercapacitor health monitoring using a balancing circuit

Bi-directional electrical characterisation of microbial fuel cell.

State of the art of High Temperature Power Electronics

Planar, Double-Layer Magnetic Inductors for Low Power, High Frequency DC-DC Converters

Temperature Dependence of 4H-SiC Ionization Rates Using Optical Beam Induced Current