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Currently the false data injection (FDI) attack bring direct challenges in synchronized phase measurement unit (PMU) based network state estimation in wide-area measurement system, resulting in degraded system reliability and power supply security. This paper assesses the performance of state estimation in electric cyber-physical system paradigm considering the presence of FDI attacks. The adverse...
In the present study, Sn0.3Ag0.7Cu spherical solders with diameter in the range of 10∼50 µm were assembled on the flux-coated Cu metallization and then reflowed at temperature of 250°C to form Sn0.3Ag0.7Cu/Cu micro-bump joints, and the size and boundary effects on the growth and morphology evolution of interfacial intermetallic compound (IMC) of micro-bump solder joints were studied. Results show...
Grain characteristics of copper filler have an important influence on physical properties of through silicon vias (TSVs) in three-dimensional (3D) packaging. Due to the mismatch of coefficients of thermal expansion (CTE) between the copper and silicon, there exist obvious thermal stresses when the TSV structure is bearing thermal load. However, the elastic response characteristics of copper can be...
With advantages of non-contact, high energy density and local heating, the laser jet solder ball bonding (SBB) technique provides a flexible packaging method for three dimensional (3D) package structure and temperature sensitive components. In previous works, the microstructure and reliability of solder joints fabricated by laser jet SBB were studied. In recent studies, the essential factors influencing...
The effects of zinc-oxide/salt with different contents in the aluminum soldering flux on the interfacial microstructure of Sn-0.7Cu/6061Al and mechanical property of 6061Al/Sn-0.7Cu/6061Al joints were investigated. Results show that the flux containing zinc-oxide and zinc-salt can effectively remove the oxide film on surface of 6061Al and result in formation of corrosion pits at the interface of the...
In order to reduce the cost of solder materials and retard the thermal shock of temperature-sensitive electronic components during packaging process, SnBi solder paste was explored to replace SnAgCu solder paste due to the low melting temperature. In this study, BGA structure Cu/solder-ball/solder-paste/Cu joints were designed and prepared to study the interfacial reactions and microstructural evolution...
The existence of microcracks in solder interconnects plays a key role in determining the performance and reliability of solder interconnects, in particular, may increase significantly the potential for brittle interfacial fracture of interconnects and reduce the thermal conductivity of the systems. Thus, characterization of the formation and propagation of microcracks is very important for evaluating...
The separation state and inhomogeneous nature of microstructure in Sn-Bi based solders can reduce the reliability of solder interconnects obviously. Notably, continuously scaling down of the feature size of solder interconnects may greatly promote the electromigation and segregation of Bi atoms in Cu/Sn-Bi/Cu interconnects under electric current stressing, which will induce the inhomogeneity of the...
In the present study, several conventional dicarboxylic acids (e.g., oxalic acid, malonic acid, succinic acid, adipic acid and glutaric acid) are selected to modify electrically conductive adhesives (ECAs) filled with micro-sized silver flakes, and so-designed ECAs have been prepared. In so-designed and prepared ECAs, dicarboxylic acids take in effect through in-situ replacement of surfactant so as...
Size effect of solder balls on the interfacial reaction and microstructural evolution of BGA structure Cu/Sn3.0Ag0.5Cu-ball/Sn3.0Ag0.5Cu-paste/Cu joints during isothermal aging at 125 °C was systematically investigated. Results show that a large amount of bulk Cu6Sn5 phase distributes in the solder matrix of joints with large solder ball size, resulting from larger outflux Cu atoms from the interface...
With the advantages of non-contact, flexible, high energy density and local heating, the laser jet solder ball bonding (SBB) technique is widely used in electronic packaging. The reliability of laser jet SBB solder joints has long been concerned. As is well known, the wettability (i.e., the spreading ability) of the molten solder on the boding pad is a key factor influencing the formation and performance...
Low-temperature soldering of 6061Al by an aluminum solder paste consisting of a purpose-designed flux and Sn-0.3Ag-0.7Cu (SAC0307) solder alloy powder with different reflow process parameters (such as the heating rate, peak soldering temperature and joint thickness) and the reliability of the soldered joints were investigated in this study. With increasing the heating rate, the spreading performance...
Thermomigration issue has attracted increasing attention as it can induce the failure of solder interconnects, owing to the migration of atoms driven by heat flux. Further, thermomigration can promote the formation of microvoids, and also induces the evolution and migration of many other types of microvoids in solder interconnects, resulting in loss of the integrity of solder interconnects and a dramatic...
In this paper, an operating parameters optimization method for SMES considering transient thermal stability is proposed. Firstly, based on the analysis of transient thermal characteristics of SMES, a neural network based transient thermal analysis model is established to test the transient thermal stability of SMES for particular application scenarios. Then, based on the proposed model, a procedure...
The solder joint's volume and interfacial reaction during the soldering significantly affect its solidification behavior and microstructure feature; further, the microstructure of the solder matrix and the intermetallic compounds (IMC) have a direct impact on the performance and reliability of the solder joint. In this study, the effects of the solder volume and interfacial reaction on the undercooling...
During the soldering process, Kirkendall voids may form at the Cu/Cu3Sn interface and in Cu3Sn compound layer. Excessive formation and growth of Kirkendall voids may increase the potential for brittle interfacial fracture, and the existence of voids will reduce the thermal conductivity. Thus, characterization of formation and growth of Kirkendall voids is very important to the evaluation of performance...
During the soldering process, Kirkendall voids may form at the Cu/Cu3Sn interface and in Cu3Sn compound layer. Excessive formation and growth of Kirkendall voids may increase the potential for brittle interfacial fracture, and the existence of voids will reduce the thermal conductivity. Thus, characterization of formation and growth of Kirkendall voids is very important to the evaluation of performance...
The solder joint's volume and interfacial reaction during the soldering significantly affect its solidification behavior and microstructure feature; further, the microstructure of the solder matrix and the intermetallic compounds (IMC) have a direct impact on the performance and reliability of the solder joint. In this study, the effects of the solder volume and interfacial reaction on the undercooling...
The component service in Web service composition may fail or degrade in QoS thus needs to be replaced. In this paper, we propose a novel approach for services replacement of the composition. The target service could be replaced individually, or it could be replaced with its related services in the composition as a whole by a more complex service. In this way, far more choices will be available to...
A dual redundancy electrical mechanic actuator designed for high-performance and high-reliable aero electrical drive systems is studied in this paper. The dual redundancy system contains two coaxial permanent magnet synchronous motors (PMSM), two independent power converters with intelligent power modules (IPM) and two position sensors. In the dual redundancy vector control, a novel space vector pulsewidth...
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