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Improvements in characteristics of magnetic materials and switching devices have provided the feasibility of replacing the electrical buses with high frequency magnetic links in micro-grids. This effectively reduces the number of voltage conversion stages, and the size and cost of the renewable energy system. It also isolates the converter ports, which increases the system safety and facilitates bidirectional...
In this paper, the effect of changes in the width of teeth and yoke on stator temperature characteristics was analyzed. An initial model of fill factor 45% was produced. The validity of the temperature analysis using the thermal equivalent circuit method was experimentally verified. A basic model was selected as the initial model. Also, a temperature characteristic analysis was performed for various...
For evaluate the thermal behavior of a permanent magnet motor under different types of losses and various loss distributions, a simplified thermal circuit is proposed. The result shows that, the model presented in the companion paper is suitable to use in machine design with certain accuracy.
A three-dimensional finite element model of miniature circuit breaker is established. The steady state temperature field is obtained by the method of electrothermal coupling, and the mechanism of overload protection is analyzed. The influence of wire size on the temperature of bimetal is studied. A simple and effective method to reduce the influence of external wire size is presented. The influence...
Surface spiral winding has been demonstrated to achieve low skin and proximity effects copper losses, and low air-gap magnetic flux density in MHz, kW level inductive wireless power transfer systems. Even though different dielectric geometries have been proposed to reduce dielectric losses, dielectric losses are still the limiting factor to further improve the coil-to-coil power transfer efficiency...
The influence of different fault modes (open-circuit fault and short-circuit fault) on the post-fault performance of six-phase fault tolerant permanent magnet synchronous motor (FTPMSM) is investigated in this paper. The copper loss of the FTPMSM under different fault modes is calculated in analytical form based on the heat equivalence principle due to the non-sinusoidal waveform of non-fault phase...
This paper focuses on investigating the influence of design parameters on characteristics of external rotor permanent magnet synchronous machine (PMSM). Under the constraint of torque density, the effects of pole number and teeth height ratio on copper and iron losses are studied, as well as motor efficiency and winding temperature rise. Finally, to meet the need of the new micro-EV C11CB by Beijing...
Optical systems-on-chip (SOCs) with integrated optical passives in the visible and near-IR range can have a tremendous impact in miniaturizing complex optical instrumentation to enable a new class of ultra-compact, low-cost optical sensors and imagers for a wide variety of emerging applications. However, while high-density image sensors are now commonplace in CMOS, all passive optical components are...
In this paper, we propose a feasible and prospective method to prepare copper-coated ceramic substrate by using nano thermo-compression bonding technology. Nanoporous copper (NPC) can be prepared by dealloying of Cu-Zn alloy system in L-tartaric acid solution. By controlling the concentration of L-tartaric acid solution and dealloying temperature, NPC presents good homogeneity and open bi-continuous...
The plasma activation is a promised process to improve the bonding performance for materials pretreated with the plasma. In this study, the chips studded with gold bumps flipped-bonding onto alumina substrates using the thermal compressional bonding. To improve the bonding performance of gold bumps onto copper electrodes, both gold bumps and alumina substrates were pretreated to Ar/H2 plasma at 400...
In this paper, the growth behavior of twin boundary in plated copper film was thoroughly investigated using SEM and TEM to facilitate its application as under bump metallization (UBM). The bath consisting of different amounts of H2SO4 was adopted to individually study the influence of pH on cross-sectional microstructure of copper film. Increasing the sulfuric acid concentration could greatly increase...
With the rapid increase in the number of integrated circuits I/O, the traditional wire bonding package has been unable to meet the high I/O number of interconnection needs, flip-chip process can undoubtedly solve the high I/O number of miniaturization package problems, especially flip-chip plastic package can fundamentally meet the increasing number of pins, improve speed and high frequency performance,...
This paper focuses on the influence of annealing process on the properties and microstructural evolution of through-silicon-via electroplating copper. Particular attention is paid to the interposer-related through-silicon-via applications, which is fabricated by via-last process with the diameter of 20 microns and above. A interposer was designed and fabricated with its diameter of 100 microns and...
Driven by the pressure of environment protection and cost reduction, direct plating as a new alternative process had been used to replace the conventional electroless copper in some factories. It is necessary to realize the potential reliability problems when using this completely plating method. An internal circuit open failure case in PCB with direct plating using conductive polymers was studied...
The joints of Au60AgCu alloy to silver and copper plated wire were obtained by using Sn63Pb solder, and the microstructure and mechanical properties of the brazing joints were investigated. The shear strength and the reliability of joints after the high and low temperature test were evaluated in this study.
Three-dimensional system integration with through-silicon-vias (TSVs) is regarded as a promising solution to the “More-than-Moore” challenge to improve the performance of micro- and nano-electronic devices. However, the copper extrusion of TSVs during the back-end-of-the-line (BEOL) process and under service conditions poses serious reliability concerns. Substantial experimental and simulation work...
The rapid development of three dimensional packaging makes it necessary to develop smaller and more reliable microbumps. In the electrodeposition process of bump cylinder, the filling quality is largely determined by the combination of additives. In this work, the effect and competitive adsorption between suppressor polyethylene glycol (PEG) and accelerator Bis-(3-sodiumsulfopropyl disulfide) (SPS)...
A method of extracting the effective copper surface roughness of a laminate in situ is introduced. The rough copper attenuation, as a function of surface roughness, is removed from the total attenuation. The residual loss is fit to coefficients, and an error is calculated based on the remaining surface roughness contribution. When the error is minimized or when the apparent surface roughness contribution...
Surface permanent magnet vernier (SPMV) motors are gaining more and more attentions over recent years due to their high torque density. Generally, most researches focuses on their applications in low speed, high torque area, and the study on their high speed operation is rarely seen. In this paper, a SPMV motor with 12 slot, 20 rotor pole is evaluated for traction application. The optimal designed...
A thermoelectric generator (TEG) can be defined as a low voltage high-current dc power with a linear I-V feature. Even though efficiencies for TEGs are as low as 3-5%, useful electricity generation is possible due to the great amount of heat emitted from almost any electric device. The idea is to convert the thermal energy from any source releasing waste heat directly to electrical energy by a thermoelectric...
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