Fully Automated Inductance Measuring System Using New Fabricated Inductance Box

Decade inductance boxes are widely used in electrical laboratories for calibration of instruments that measure inductance. The main aim of this paper is to construct a new inductance box providing a huge number of automated inductance steps, which are used in the laboratories to perform full automatic calibration of inductance meters. Therefore, a new inductance box has been introduced that mainly consists of three decades. The three inductance decades have the same design, but each has its four different internal inductive elements. Each decade can generate 15 different inductance values, so it is more economical and practical compared to the other ordinary decades, which produce only 10 values by using 10 internal inductive elements. 1666 different inductance values can be obtained from this inductance box, while 4096 inductance values can be obtained by the possible combinations of its three decades steps. Practical design, fabrication and specifications of this new inductance box are demonstrated in detail. It is designed to achieve relative accuracy in the range from 5 × 10^?4 to 5 × 10^?3. It could be used to perform full automatic inductance measurements at the National Institute of Standards, Egypt, for the first time. Comparison between an ordinary inductance box and the new introduced one has been made to validate its performance.     

Electrolytic capacitors produced from deformation-processed two-phase alloys

Arc cast Cu-Ta and powder processed Al-Ta and Al-Nb composite alloys have been examined as potential materials for making electrolytic capacitors. These two phase alloys can be severely cold-worked, deformation-processed, to produce Ta surface areas considerably larger than those possible with the powder processing used in current Ta capacitors. The three alloys were deformation-processed into sheet and rod form and then processed through anodization, electrolyte formation and cathode fabrication steps to make prototype capacitors. The capacitors were tested for capacitance, effective series resistance and leakage. The figure of merit,CVg^–1, (capacitance × voltage per gram) values obtained closely approached those of currently manufactured capacitors but d.c. leakage values were unacceptably high using a solid electrolyte. To realize the full potential of this new method for fabricating Al-Ta capacitors further research is required to improve the deformation of the Ta powders and to find methods of anodization and solid-state electrolyte formation capable of maintaining oxide film integrity.     

Evaluation of a Capacitance Scaling System

An improved error analysis of an existing capacitance scaling system for supporting measurements of higher valued (10 nF to 100 ) ceramic-dielectric four-terminal-pair (4TP) capacitance standards over the 100-Hz to 100-kHz frequency range is described. The capacitance scaling system uses a commercial impedance (inductance-capacitance-resistance) meter and a single-decade inductive voltage divider as an impedance comparator. Four-terminal-pair capacitors in decade (10 : 1) steps from 10 nF to 100 F are measured. The system's 10 : 1 scaling error is determined using 100-pF and 1-nF air-dielectric 4TP capacitance standards with known capacitance and loss characteristics over frequency. This paper discusses the significant reductions in measurement uncertainty that were attained through the use of improved calibration standards and measurement method refinements. Details of the uncertainty analysis for a 10-nF capacitor (in the 100-Hz to 10-kHz frequency range) and verification data are presented.     

New Fused-Silica-Dielectric 10-and 100-pF Capacitors and a System for Their Measurement

New instruments have been designed to bring to standards laboratories the improved accuracy of capacitor calibrations developed by the National Bureau of Standards. The new 10-and 100-pF reference standard capacitors, based upon an NBS design, use a fused-silica dielectric with gold electrodes to provide the time and voltage stability required for calibrations to parts in 107. To maintain the capacitor temperature constant to within 0.01 °C, one model of the capacitors is designed for use in an oil bath, the other model is fitted with a new, stable, thermostatically controlled air bath. The system to measure these capacitors with a precision of parts in 108 consists of a bridge, detector, and oscillator. For these special measurements and for the general calibration of a wide range of capacitors, the new transformer-ratio-arm bridge has 12 capacitance decades and a range of 10 MAF-10-7 pF, and five conductance decades and a range of 103110-10 tmho. The new phasesensitive detector and power oscillator provide high sensitivity to bridge imbalance over the frequency range 10 Hz-100 kHz.     

Fabrication of Ag/PVA nanocomposites and their potential applicability as dielectric layer in thin film capacitor

Over the past decade, polymer–metal nanocomposites have drawn a great deal of attention due to their extensive application in organic flexible devices. Here, we describe the synthesis and characterisation of silver–polyvinyl alcohol nanocomposite thin films and investigates the possibility of application of these composite films as dielectric layer in efficient capacitors. The material characterisation is done through UV–vis absorption, scanning electron microscopy and atomic force microscope. The dielectric property of the nanocomposite material is investigated with a LCR meter. The different fabricating parameters for generating homogeneous thin films are optimised in this investigation. The composite material thin films exhibit high capacitance density and low dielectric loss and hence they may be suitable ingredients for high capacitance capacitors.     

A Novel Spacer Process for Sub-10-nm-Thick Vertical MOS and Its Integration With Planar MOS Device

We demonstrate vertical capacitors using a novel spacer process capable of fin thickness down to 5 nm. We also integrate this process compatibly with planar devices on the same die using minimal additional mask steps. Various implant conditions, order of implant step, and starting substrate dopings are studied and best conditions identified through TSUPREM4 simulations and later through experiments to ensure process robustness and dopant tunability for the vertical devices as well as to ensure comparable performance for planar and vertical devices. In anticipation of usage of this process in a high-density environment, the impact of isolation density on the leakage characteristics of vertical capacitors is also studied. After simultaneously fabricating planar and vertical structures, electrical characterization using capacitance–voltage (C–V) and current–voltage (I–V) measurements is performed. Functional capacitors for both types of devices are obtained. Oxide thickness is backtracked using I–V, C–V, and TEM and yield consistent results. The leakage current shows expected trends with voltage and is successfully fitted using prevalent tunneling models. The vertical structures are found to suffer from two problems: a larger leakage current and an additional planar parasitic capacitance due to a finite polysilicon gate thickness. The larger leakage is attributed to thin corners as confirmed by higher leakage in structures having a larger fraction of corner area (higher isolation density structures). A modified novel vertical device process circumventing both these problems by yielding thicker bottom and corner oxides is proposed and experimentally demonstrated. Finally, a path to extending this process for vertical transistor fabrication is shown in simulations.     

快递箱辅助把手对搬运作业舒适度的影响

目的 旨在探索工人在手工搬运工作中最佳的快递箱辅助把手结构,并以该研究为基础提出在快递箱设计时更具舒适性的建议。方法 募集35名被试者使用4种不同辅助把手的快递箱执行2项手工任务（提举任务、携带任务）,测试了被试者的最大可接受重量,并记录了其身体部位的不适感、心率和总体喜好度。通过调研法和生理测量仪器测量法得到消费者对4种不同辅助把手的快递箱样本的主观评价和测量数据来分析生理负荷。结果 结果表明,在2项手工任务中,使用4种快递箱时心率的变化均无显著差异,手腕部的不适感也是如此。快递箱C的手掌部位不适感明显高于其他样本。在提举任务中,快递箱C的最大可接受重量和总体偏好等级最高。在携带任务中,快递箱B的最大可接受重量和总体优先等级最高。结论 证明了对于负载提举作业,位置偏上的把手位置是首选。在携带作业中,较低位置的把手对手工作业更友好。此外,提供更多容放手的空间以便轻松握住把手对于提高舒适度非常重要,并且更平滑和更大的接触面积可以减轻手掌的不适感。     

Integrated ferroelectric stacked mim capacitors with 100 nF/mm2and 90 V breakdown as replacement for discretes

This paper shows for the first time integrated thin film ferroelectric metal-insulator-metal capacitors on silicon with a record high capacitance density above 100 nF/mm² combined with a breakdown voltage of 90 V and a lifetime exceeding 10 years at 85degC and 5 V. The high capacitance density was obtained by a combination of material optimizations resulting in a dielectric constant of 1600, and stacking of capacitors. The reliability of these ferroelectric capacitors was studied in detail with accelerated lifetime testing. The high performance of the integrated capacitors in this paper shows great potential for applications demanding high capacitance densities combined with electrostatic discharge protection.     

Reference trimmer disc capacitor for frequencies up to 200 Mc

Conclusions The above disc capacitor can be used for various purposes as a reference single-valued effective capacitance, or as a many-valued capacitance set at will to any value within its range, for testing or research purposes.The KVCh-8M capacitors are particularly convenient for determining the frequency characteristic of effective capacitances of other capacitors by the substitution method. In this method the measured capacitor is replaced at the high frequency by the KVCh-8M capacitor, which is set to the appropriate value by adjusting the distance between its plates.The preliminary adjustment is made with the capacitor screen removed, and the final adjustment through the opening in the screen.The actual capacitance of the disc trimmer is then calculated from (4) having measured its capacitance on a low-frequency bridge. Such a method of checking capacitors is very simple, since it does not require any accurate high-frequency capacity measuring devices. It is quite sufficient to have any type of Q-meter.     

Capacitively-Coupled SQUID Bias for Time Division Multiplexing

The multiplexing scheme presented in this paper is part of the readout chain of the QUBIC instrument devoted to cosmic microwave background polarization observations. It is based on time domain multiplexing using superconducting quantum interference devices (SQUIDs) to read out a large array of superconducting bolometers. The originality of the multiplexer presented here lies in the use of capacitors for the SQUID addressing. Capacitive coupling allows us to bias many SQUIDs in parallel (in a 2D topology), with low crosstalk and low power dissipation of the cryogenic front-end readout. However, capacitors in series with the SQUID require a modification of the addressing strategy. This paper presents a bias reversal technique adopted to sequentially address the SQUIDs through capacitors using a cryogenic SiGe integrated circuit. We further present the different limitations of this technique and how to choose the proper capacitance for a given multiplexing frequency and current source compliance.     

Research on Activated Carbon Supercapacitors Electrochemical Properties Based on Improved PSO-BP Neural Network

Supercapacitors, also called electrical double-layer capacitors (EDLCs), occupy a region between batteries and dielectric capacitors on the Ragone plot describing the relation between energy and power. BET specific surface area and specific capacitance are two important electrochemical property parameters for activated carbon EDLCs, which are usually tested by experimental method. However, it is misspent time to repeat lots of experiments for EDLCs' studies. In this investigation, we developed one theoretical model based on improved particle swarm optimization algorithm back propagation (PSO-BP) neural network (NN) to simulate and optimize BET specific surface area and specific capacitance. Comparative studies between the predicted data and experimental data-earlier deduced by Liu et al, have revealed that improved PSO-BPNN model bears higher prediction accuracy, faster computation speed and better generalization performance.It is concluded that the improved PSO-BP NN is one simple and effective method to find optimal conditions of BET specific surface area and specific capacitance for activated carbon EDLCs.     

Polarization-switching D/A converter

This paper describes a novel digital-to-analog (D/A) conversion technique, which uses the analog quantity polarization as a D/A conversion medium. It can be implemented by CMOS capacitors or by ferroelectric capacitors, which exhibit strong nonlinearity in charge versus voltage behavior. Because a ferroelectric material inherently has spontaneous polarization and generally has a large dielectric constant, the effective capacitance of a ferroelectric capacitor is much larger than that of a CMOS capacitor of the same size. This ensures less influence of bottom-electrode parasitic capacitance on a ferroelectric capacitor. Furthermore, a data converter based on ferroelectric capacitors possesses the potential nonvolatile memory function owing to ferroelectric hysteresis. Along with the architecture proposed for polarization-switching digital-to-analog converter (PDAC), its circuit implementation is introduced. Described is implementation of two 9-bit bipolar PDACs: one is based on CMOS capacitors and the other on off-chip ferroelectric capacitors. Experimental results are presented for the performance of these two prototypes.     

碳纳米管表面沉积氧化镍及其超电容器的电化学行为

通过催化裂解法制备了碳纳米管并进一步制备了碳纳米管薄膜电极.基于该种材料的超电容器电极比容量达到36F/g.研究了在碳纳米管薄膜基体上使用电化学方法沉积氧化镍的新工艺,制备出碳纳米管和氧化镍的复合电极.电化学测试证明复合电极的比容量提高到52F/g以上且基于这种复合电极的超电容器具有极低的自放电率.     

Alloy design: a historical perspective

This paper presents a historical perspective of the progress of mankind from the bronze age to the present stage in alloy development. In particular, the last four decades have seen empiricism giving way to intelligent and informed design of alloys. A spectacular example from this decade is the design of metallic glasses with optimum magnetic properties in 1979.     

Next generation integral passives: materials, processes, and integration of resistors and capacitors on PWB substrates

Integral passives are becoming increasingly important in realizing next generation electronics industry needs through gradual replacement of discretes. The need for integral passives emerges from the increasing consumer demand for product miniaturization thus requiring components to be smaller and packaging to be space efficient. In this paper, the feasibility of integration of polymer/ceramic thin film (5 m thick) capacitors (C) with other passive components such as resistors (R) and inductors (L) has been discussed. An integrated RC network requiring relatively large capacitance and resistance is selected as a model for co-integration of R and C components using low temperature PWB compatible fabrication processes. This test vehicle is a subset of a large electrical circuit of a functional medical device. In order to produce higher capacitance density and reduce in-plane device area, multi-layer (currently two-layer) capacitors are stacked in the thickness direction. A commercially available Ohmega-Ply resistor/conductor material is selected for integral resistors. Resistors were fabricated using a multi-step lithography process with the utilization of two separate masks. Bottom copper electrodes for capacitors were also defined during the resistor fabrication process. Photodefinable epoxies filled with a high permittivity ceramic powder were used for fabrication of thin film capacitors. Epoxy and ceramic powders were mixed in the required proportion and blended using a high shear apparatus. The coating solution was homogenized in a roll miller for 3 to 5 days prior to casting in order to prevent settling of the higher density ceramic particles. Capacitors were fabricated by spin-coating on the sub-etched copper electrodes. The deposited dielectric layers were dried, exposed with UV radiation, patterned, and thermally cured. Top capacitor electrodes (copper) were deposited using a metal or an e-beam evaporator. The electrodes were patterned using the standard photolithography processes. Selected good samples were used for depositing the second capacitor layer. The RC network is extended to incorporate electroplated polymer/ferrite core micro-inductors through the fabrication of an industry prototype low pass RLC filter. Meniscus coating was evaluated for large area manufacturing with high process yield. A capacitance density of 3 nF cm^–2 was obtained on a single layer capacitor with 6 m thick films. The capacitance density was increased to 6 nF cm^–2 with the two-layer deposition process. The capacitors were relatively stable up to a frequency range of 120 Hz to 100 KHz. Meniscus coating was qualified to be a viable manufacturable method for depositing polymer/ceramic capacitors on large area (300mm x 300mm) PWB substrates. Dielectric constant values in the range of 3.5 to 35 with increase in filler loading up to 45 vol% were achieved in the epoxy nanocomposite system where the dielectric constant of the host polymer was limited to 3.5. Higher dielectric constant polymers are required to meet the increasingly higher capacitance needs for the next generation electronics packaging. Possible avenues for achieving higher capacitance density in polymer/ceramic nanocomposite system have been discussed.     

预炭化对KOH活化石油焦的结构及电容性能的影响

以不同温度炭化的石油焦为原料、KOH为活化剂制备电化学电容器用炭电极材料. 采用XRD、TEM和N₂吸附法对前驱体及活化产物的结构进行了表征, 并考察了样品的电化学性能. 结果表明: 通过调整前驱体的预炭化温度, 可实现对石油焦基活性炭的微晶结构和孔结构的调控, 分别制得无晶体特性的高比表面积活性炭和由大量类石墨微晶构成的低比表面积活性炭. 低表面积活性炭依靠充电过程中电解质离子嵌入类石墨微晶层间而实现能量存储, 具有比高比面积活性炭高10倍的面积比电容和更大的体积比电容.     

Effects of moisture absorption on the electrical parameters of embedded capacitors with epoxy-BaTiO3 nanocomposite dielectric

In this work the effects of moisture absorption on the electrical parameters of embedded capacitors is investigated. Capacitors of two different areas embedded inside a four-layered printed wiring board were selected for this work. The dielectric was a nanocomposite of epoxy and BaTiO₃ which is common dielectric material used in embedded capacitors. These capacitors were exposed to elevated temperature and humidity conditions (85?°C and 85% RH) and two parameters, capacitance and dissipation factor, were measured in situ. The diffusion of moisture in the dielectric was also modeled using the finite element method (FEM), and the changes in electrical parameters were calculated theoretically. The FEM methodology was then verified by applying it on capacitors of different dimensions.     

Modern high precision bridges for measuring inductance and capacitance at audio frequencies

Summary Bridges of the type of 716-B and TM-351 and in general Schering type bridges can be considered as most suitable for measuring capacitance. The wide use of such bridges permits one to consider them as standard for the purpose.Attention should also be drawn to bridges with inductive ratio arms which possess very valuable properties: they require a small number of standard capacitors, they can measure the capacitance not only of two- but also of three-terminal capacitors, in this respect they are in no way inferior to the Schering circuit. Another property of these circuits should also be noted, they cannot be used at frequencies below 200 cps which rather limits their range of application as compared with some other circuit.Soviet industry has not as yet progressed very far in making capacitance bridges. Manufacture of bridges similar to type 716-B and TM-351 has begun.As far as the inductance bridges are concerned it is advisable to refrain, on the basis of the experience gained, from manufacturing bridges similar to TM-282 and completely reject the principle on which bridge 667-A is constructed, and which was criticized above. On the other hand improved types which are theoretically completely acceptable (such as the Sullivan AC-1100 or the Siemens Halske Rel-3R-114) will be too complicated for mass production. In addition the accuracy of the above-mentioned Siemens bridge may, despite many of its other advantages, prove to be in many cases inadequate.The difficulties thus arising in the choice of an inductance bridge circuit may perhaps be resolved by M. A. Bykov's proposal [5] of using a modified Anderson circuit for direct reading measurements. This modification opens up great possibilities in measuring small inductances with small Q factors, which is the great difficulty in bridge design; yet the Anderson circuit which gives a perfect balance, can, with the proposed modification, provide convenient measurements up to 0.01 h. At higher values it is advisable to use a Maxwell circuit in its usual form, as for instance in the TM-382 bridge. Work in one of the development departments, according to available information, is being conducted on these lines.     

BaTiO3–P(VDF-TrFE) composite ink properties for printed decoupling capacitors

In this research a composite for printable capacitors using screen printed structures and low temperature curing ferroelectric ink was investigated. The realized ink consisted of 40 vol% barium titanate in a poly(vinylidenefluoride-trifluoroethylene) matrix. DuPont silver ink 5064H was used for the conductive lines in the design and the maximum process temperature was 130 °C. The thickness of the composite and the area of the printed capacitor were 43 μm and area 25 mm², respectively. The obtained relative permittivity of the composite was 46 and the tan δ was 0.15 at 1 MHz. Additionally, the microstructure of the composite was investigated and the temperature dependence of the dielectric properties measured. The capacitance of the parallel plate structure was approximately 200 pF at 1 MHz. This is easily adjustable by changing the printing pattern, number of layers or the filler loading. The freedom of choice in integration and capacitance value selection makes the ink highly usable in, for example, decoupling capacitors that are compatible with inorganic, organic and even flexible, substrates.     

Billiards Optimization Algorithm: A New Game-Based Metaheuristic Approach

Metaheuristic algorithms are one of the most widely used stochastic approaches in solving optimization problems. In this paper, a new metaheuristic algorithm entitled Billiards Optimization Algorithm (BOA) is proposed and designed to be used in optimization applications. The fundamental inspiration in BOA design is the behavior of the players and the rules of the billiards game. Various steps of BOA are described and then its mathematical model is thoroughly explained. The efficiency of BOA in dealing with optimization problems is evaluated through optimizing twenty-three standard benchmark functions of different types including unimodal, high-dimensional multimodal, and fixed-dimensional multimodal functions. In order to analyze the quality of the results obtained by BOA, the performance of the proposed approach is compared with ten well-known algorithms. The simulation results show that BOA, with its high exploration and exploitation abilities, achieves an impressive performance in providing solutions to objective functions and is superior and far more competitive compared to the ten competitor algorithms.