基于RC-RL串联电路测量电阻值

根据串联电路的特点和容抗、感抗的计算公式,推导电阻值的计算公式,分别利用万用表测量电阻器、电容器、电感器两端电压,代入计算公式,得出实际电阻值,并与标称电阻值相比,分析两者之间的误差。同时,在其他参数不变的情况下,不断调整电阻值大小,分析不同电阻值的计算结果与标称电阻值之间的误差。实践表明,该电路元件少、体积小、价格低廉。该方法计算速度较快、计算难度较低、测量精度较高、测量范围较广。     

高阻硅低温欧姆接触

提出用激光诱导扩散法在室温电阻率大于15,000(Ω·cm)的P型高阻硅上制备低温欧姆接触(77—300K).研究了激光参数对低温比接触电阻值的影响关系,结合诱导区表面热学性质的理论计算讨论了实验结果.比较了二种不同的铟焊引线方法.     

测量计算金属-半导体接触电阻率的方法

如何测量、计算得到精确接触电阻值已凸显重要.介绍了多种测量计算金属-半导体欧姆接触电阻率的模型和方法,如矩形传输线模型、圆点传输线模型、多圆环传输线模型等,对各方法的利弊进行了讨论,并结合最新的研究进展进行了评述和归纳.综合多种因素考虑,认为圆点传输线模型是一种较好的测量金属半导体接触电阻率的方法.     

综合通信大楼基础接地电阻值的计算

介绍了综合通信大楼基础接地电阻值的四种计算方法，并将计算值与实测值进行了比较。     

压敏电阻器的电阻值

压敏电阻器是一种限压型非线性电阻器,主要用于抑制浪涌过电压。通常不用电阻值而用电压(压敏电压、限制电压)或电流(漏电流、最大脉冲电流)来描述它的特性。但是,在有些问题中,例如在压敏电阻器的冲击电流试验中,要考虑它与冲击电流发生回路的匹配问题,这时用电阻值这个参数就更为方便。根据作者在研制压敏电阻器测试仪器中所进行的实验,对压敏电阻器的电阻值这个参数作一些讨论。     

防雷接地检测电阻值偏离真值的原因和对策

针对防雷检测工作中经常出现的接地电阻值偏离真值的现状,从接地电阻测试仪原理出发,归纳了造成接地电阻值偏离真值的八大常见原因,提出了避免或减小接地电阻值偏离真值的方法.     

SiC接触的电学和化学特性

用化学和电学方法研究测定了６Ｈ－ＳｉＣ与元素金属（Ｎｉ，Ｍｏ）和硅化物（ＭｏＳｉ＿２，ＴａＳｉ＿２和ＴｉＳｉ＿２）的接触特性。用俄歇电子光谱（ＡＥＳ）化学分析技术研究了由热处理引起的界面反应。在退火过程中，用电学测量方法（电流－电压和电容－电压）测量了整流特性或欧姆接触特性。并尽可能地计算了势垒高度及接触电阻值。     

SiC接触的电学和化学特性

用化学和电学研究测试了６Ｈ－ＳｉＣ与元素金属（Ｎｉ，Ｍｏ）和硅化物（ＭｏＳｉ２，ＴａＳｉ２和ＴｉＳｉ２）的接触特性。用俄歇电子光谱（ＡＥＳ）化学分析技术研究了由热处理引起的界面反应，在退火过程中，用电学测量方法（电流－电压和电容－电压）测量了整流特性或欧姆接触特性。并尽可能地计算了势垒高度及接触电阻值。     

测试系统继电器电阻值异常的工程学分析及解决

介绍了对于测试系统接触测试项目出现异常所做的分析,最终定位问题出现在测试系统继电器的电阻值的异常,经过分析和试验,其异常的原因归结为测试系统针对特定结构的被测产品因为考虑不周而使悬空的测试线路带有超过允许范围的电荷,导致在之后的继电器开关过程中对触点造成伤害.文中提出了解决方案并通过实践验证解决方案的可行性.     

降低岩石山接地电阻值的方法

为解决偏远山区收看广播电视节目问题,沙河市在高山顶上分别建立了3座电视信号发射塔和配套的多路电视信号发射机,为确保发射设备免遭雷击的危害,我们到实地进行勘查,测试3处的电阻率都在3 000～4 000 Ω·m之间,要使接地电阻值小于4 Ω,必须采取措施降低接地电阻值,为此,我们同有关厂家联系,根据实际情况采用如下方法降低岩石山接地电阻值:     

Serial-layered-transmission line contact-resistance representation for partially-overlaid Al-to-contacts to silicon

We have developed a contact resistance representation for metallurgical systems having two interfacial conductive and resistive layers to a semiconductor surface. This configuration results when an interconnect metal (e.g. Al), which only partially overlays a contact metal (e.g. silicide), reacts with it to form a less conductive interface. As a consequence, circuit designers can take advantage of the unreacted region's lower contact resistance to ease circuit layout constraints. Contact resistance minima are suggested by the degree of overlaid or reacted segment and specific contact resistance degradation trade-off. A coupling of two layered transmission lines is used to simulate these two segment contacts. The model is compared to measurements of hardware.     

Effects of different loads on the surface of silver metal oxide contacts for general-purpose relays

Silver metal oxides have become very popular as contact materials in electromechanical switching devices due to their high resistance to erosion and contact welding. Initially, these materials were developed for contactors and circuit breakers. Investigations on silver metal oxide contacts for general-purpose relays were conducted in order to gain an insight into the effects and failure mechanism of such contacts under specific loads, such as resistive and inrush current loads. It will be shown that contact failures may be influenced by very thin silver layers on the surface of silver metal oxide materials and the behavior of these layers at thermal stress. The silver layers are a result of the mechanical treatment in the production of rivets and the following riveting process. The results support the development of new silver metal oxide materials for general-purpose relay applications.     

新一代导电胶材料接触电阻稳定性研究

文中主要针对环保型集成电路封装中替代SMT焊料的新一代导电胶进行了介绍,重点研究了导电胶材料在封装应用中接触电阻稳定性方面的问题,对于填充金属的导电胶,分析了其老化过程中接触电阻稳定性的问题,提出了影响其接触电阻稳定性的物理机制,并通过实验方法加以分析和讨论。     

A Pyrenylpropyl Phosphonic Acid Surface Modifier for Mitigating the Thermal Resistance of Carbon Nanotube Contacts

Efforts to utilize the high intrinsic thermal conductivity of carbon nanotubes (CNTs) for thermal transport applications, namely for thermal interface materials (TIMs), have been encumbered by the presence of high thermal contact resistances between the CNTs and connecting materials. Here, a pyrenylpropyl‐phosphonic acid surface modifier is synthesized and applied in a straight forward and repeatable approach to reduce the thermal contact resistance between CNTs and metal oxide surfaces. When used to bond nominally vertically aligned multi‐walled CNT forests to Cu oxide surfaces, the modifier facilitates a roughly 9‐fold reduction in the thermal contact resistance over dry contact, enabling CNT‐based TIMs with thermal resistances of 4.6 ± 0.5 mm² K W^?1, comparable to conventional metallic solders. Additional experimental characterization of the modifier suggests that it may be used to reduce the electrical resistance of CNT‐metal oxide contacts by similar orders of magnitude.     

导电胶粘接元件接触电阻的稳定性研究

为解决导电胶粘接元件接触电阻不稳定的问题,研究了在温度及压力应力条件下,导电胶在不同界面的导电性和体电阻率的变化情况,分析了导电胶接触电阻不稳定的机理。试验结果表明,导电胶粘接片式元件的接触电阻的稳定性不仅与工艺加工过程有关,而且与元件端头金属基材表面金属化层的电极电动势密切相关;采用Ag基或Au基端头元件时,其导电胶粘接元件的接触电阻在粘接装配工艺过程中是最稳定的。     

新型接触电阻检测仪的应用

互连器件接触电阻检测,一直是系统连接后判别每个接点接触是否可靠良好,必须解决的实际问题。随着高密度、小型化的互连器件在电子电气设备上的广泛应用,如何解决互连器件接触电阻的在线自动检测,己成为确保互连器件质量和可靠性的关键。文中在详细阐述接触电阻检测原理的基础上,介绍了新研制的TDO-MCR-07A多接点接触电阻检测仪特点、检测方法和主要技术参数,以及连接电脑和工装组成自动检测系统后,成功用于保险丝盒接触电阻自动检测的实例。     

Electrical Contact Resistance Degradation of a Hot-Switched Simulated Metal MEMS Contact

Electrical contact resistance testing was performed by hot-switching a simulated gold-platinum metal microelectromechanical systems contact. The experimental objective was to determine the sensitivity of the contact resistance degradation to current level and environment. The contact resistance increased sharply after 100hot-switched cycles in air. Hot-switching at a reduced current and in nitrogen atmosphere curtailed contact resistance degradation by several orders of magnitude. The mechanism responsible for the resistance degradation was found to be arc-induced decomposition of adsorbed surface contaminants     

Laser‐fired contact for n‐type crystalline Si solar cells

Laser‐fired contacts to n‐type crystalline silicon were developed by investigating novel metal stacks containing Antimony (Sb). Lasing conditions and the structure of metals stacks were optimized for lowest contact resistance and minimum surface damage. Specific contact resistance for firing different metal stacks through either silicon nitride or p‐type amorphous silicon was determined using two different models and test structures. Specific contact resistance values of 2–7 mΩcm² have been achieved. Recombination loss due to laser damage was consistent with an extracted local surface recombination velocity of ~20 000 cm/s, which is similar to values for laser‐fired base contact for p‐type crystalline silicon. Interdigitated back contact silicon heterojunction cells were fabricated with laser‐fired base contact and proof‐of‐concept efficiencies of 16.9% were achieved. This localized base contact technique will enable low cost back contact patterning and innovative designs for n‐type crystalline solar cell. Copyright © 2014 John Wiley & Sons, Ltd.     

Resistance Analysis of Spherical Metal Thin Films Combining Van Der Pauw and Electromechanical Nanoindentation Methods

Although micron-sized metal-coated polymer particles are an important conductive filler material in anisotropic conductive adhesives, the resistance of the particles in an adhesive is not well understood. In this study, a van der Pauw method for spherical thin films is developed and applied to determine the resistivity of 30 μm silver-coated poly(methyl methacrylate) (PMMA) particles. The resistivity is used to interpret resistance contributions in single particle electromechanical nanoindentation measurements, which simulate the compression particles undergo in application. The resistivity was found to be coating thickness dependent for thin films in the range 60–270 nm. Estimation of the resistance of the metal shell using the measured resistivity did not account for the total resistance measured in electromechanical nanoindentation. We therefore deduce a significant contribution of contact resistance at the interfaces of the particle. The contact resistance is both coating thickness and particle deformation dependent.     

Emitter excess resistance in GaAlAs/GaAs heterojunction bipolar transistors

Numerous studies have shown the influence of parasitic elements, particularly emitter access resistance and inductance, on HBTs DC and dynamic performances. Instead the achievement of low specific contact resistances, the apparent emitter resistance presents high values. To explain this discrepancy the longitudinal distribution of the emitter current has been investigated by using a distributed DC-model, taking into account the metal layers resistance of the different contacts. Thus it is shown that only the emitter contact parameters act on the non equipotentiality along the structure.