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A battery separator isolates anode and cathode electrically and contributes to the ionic conductivity on the one side. On the other side, it is a highly sensitive functional component concerning mechanical loads. During production as well as the operation of a battery this thin, polymer based film is stressed by compressive and tensile forces. This contribution presents an enhanced characterization...
In earlier work it was recommended that accelerated tests, using elevated currents, be used to evaluate the performance of contact designs using materials that may be susceptible to electro-migration. This is necessary since it was found in earlier work that the type of self-diffusion in some cases had a major impact on time to failure. Since the type of diffusion is generally not known in advance,...
Through past testing it has been observed that the endurance life of contacts tested using DC automotive type loads is better if the polarity of the test is set to use the terminal contact as the anode as opposed to using the thin contact spring as the anode. A DOE approach was used to look at the effect on contact erosion and transfer for changing the thermal characteristics of the terminal with...
A one-dimensional electrochemical DC pulse simplified model for an 8Ah lithium ion phosphate battery monomer is built with the help of COMSOL software on the base of the porous electrode theory. Based on the experimental data and analysis, the model can be optimized by putting the values of effective conductivity and the concentration of the lithium at different temperature as well as the equilibrium...
A model is developed to determine the peak current required to weld large area closed contacts with ‘n’ points of contact when passing short duration, high fault currents. The model also predicts the threshold welding current for parallel contact structures used to carry large currents in high current switching devices. The model considers: (1) the total contact resistance of the closed contacts by...
This paper presents a comparison of the thermal properties between infiltrated and non-infiltrated copper windings. The focus is on thermal conductivity in the radial direction on the winding. The samples have a fill factor above 65 % due to the manufacturing method of the samples. Samples are produced and measured with the transient plane source technique and then compared to FEM simulations and...
The Copper-Chromium (CuCr) contact material is the most widely used material for the contacts of the vacuum interrupters (VI). Performance of the VI is greatly influenced by the properties of contact materials. During switching operations, such as short-circuit current interruption, a vacuum arc is generated which in turn produces melted and resolidified layers at the contact surface. Melting followed...
The resistance of vacuum interrupters can be calculated from the geometry and resistivity of current carrying parts and the additional resistance of the contact points between movable and fixed contacts. Since vacuum interrupter contacts are designed as flat contacts facing each other, the resistance is mainly determined by contact force, hardness and resistivity of the contact material. It is known...
Terahertz time-domain spectroscopy was used as a nondestructive and a noncontact optical probe to investigate the material properties and high frequency carrier dynamics of undoped and Al-doped ZnO nanowires (NWs). The frequency dependent refractive index was first determined through effective medium theory and numerical iteration process applied to the detected terahertz signals transmitted through...
Electrode material seriously influences the characteristics of vacuum arc and further affects the performance of switches. In this paper, thermal processes of six kinds of metal anodes (including pure metal and alloy anodes) are simulated and researched. Two kinds of temperature calculation methods are used. Simulation results show that W and Mo anodes have the higher temperature than Cu, Cr, CuCr25...
A THz TDS study of permittivity and conductivity properties of new variant of Yttria-stabilized-Zirconia (YSZ) produced using tape-cast method is reported. This study extends the frequency coverage of some of the previously published work. We find a general agreement with published results but the frequency gap in the mm-wave range needs to be measured more carefully before final conclusions on the...
This paper deals with the development of a new test stand for determination the thermal conductivity of metals, semiconductors, highly conductive die attaches and substrates using the steady state technique. We designed the test stand and optimized it by FE simulation to have flexibility for the selection of the sample size and measurement parameters. We determine the thermal conductivity from the...
This paper presents SPICE modeling of Phase-change Random Access Memory (PCRAM). Different models of PCRAM have been already proposed but those models still lack capability to exactly model the behavior of PCRAM. In this paper we have introduced various physical parameters in the programming, to accurately model PCRAM behavior. The modeling of PCRAM cell has been done in Verilog-A and simulation results...
To meet the requirements for future fine pitch and high-performance interconnects in advanced packaging, ICAs with nano-materials are attracting more and more interest due to their specific electrical, mechanical and optical properties. There has been extensive research on nano-conductive adhesives containing nanofillers such as nanoparticles, nanowires or carbon nanotubes. In this paper, copper nanoparticles...
According to Moore's Laws, complexity and power densities of electronic devices are increased during the last decades, moreover their dimensions are shrinking to nanometers causing hot-spot temperature escalation. Thermal management, therefore, becomes a critical issue for next generation of electronics. This scenario motivates development of novel thermal conductive adhesive (TCA) with enhanced thermal...
First principles-based calculations of the electronic and phonon properties of monolayer MoS2 are performed to assess the thermoelectric performance of this 2D material. By comparing monolayer MoS2 to bulk Bi2Te3, a good and well-characterized thermoelectric, it is found that the intrinsic properties of MoS2 are similar to Bi2Te3 in terms of thermoelectric figure-of-merit. While the advantage of Bi...
Thermal issues increase with the electronic industry pushing towards fast in high speed, high density, and high performance. Thermal conductive materials are strongly demanded for increasing heat dissipation and reducing operating temperature of devices. Hexagonal boron nitride (h-BN) nanosheet that owns high thermal conductivity and low coefficient of thermal expansion is a good filler candidate...
Thermal interface materials (TIMs) which consist of metal foil and soft cushion are used in the process of chip processor platform validation (PPV) process, and some defects, such as the stains caused by debris peeled off from TIMs due to stress concentration, were found on the surface of the chips and they had an hazardous influence in the testing process. As well as that, the thermal resistance...
This paper describes a study of automatic composition design software for human body-equivalent phantoms. Based on adaptive multiple regression analysis, this software enables engineers to efficiently design a target phantom for experiments. The materials water, silicone emulsion, glycerin, sodium chloride, and agar can be used to compose human body-equivalent phantoms. This paper will also present...
Measurements of physical transport properties of thermoelectric materials are plagued by large uncertainties (of tens of percent). Development of new materials towards larger efficiency in converting heat into electrical energy would benefit from improved measurement reliability. We are proposing to extend the 3ω method for the simultaneous measurement of the Seebeck coefficient, electrical conductivity...
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