钉基厚膜应变电姐力敏模型的初始讨论

摘要：通过分析钌基厚膜应变电阻的隧道势垒模型，提出力敏模型。     

钌基厚膜应变电阻力敏模型的初始讨论

通过分析钌基厚膜应变电阻的隧道势垒模型,提出力敏模型。用Bi2O3和RuO2合成Bi2Ru2O3并进行试验,发现应变系数随导电相粒径的增大而增大。用力敏模型解释了这一现象,并解释了其他力敏现象,诸如应变系数随势垒高度的增大而增大。     

烧结温度对厚膜电阻的影响研究

以钌系R-2200厚膜电阻浆料作为研究对象,探讨了烧结温度、保温时间和升温速率工艺因素对其阻值及电阻温度系数(TCR)的影响。利用导电机理模型和液相烧结模型,说明了烧结工艺对钌系厚膜电阻性能的影响。实验数据与SEM表明:厚膜浆料烧结温度在875℃时,结构均匀且致密性好;烧结温度过低时,结构不稳定,功能相没有形成导电网络;而烧结温度过高时,RuO2晶粒异常长大,导电链断裂,势垒升高。     

电子元件、组件

TN60 2004050570钉基厚膜应变电阻力敏模型的初始讨论/丁鹏,马以武(中国科学院合肥智能机械所)11电子器件.一2 004,27(1)一63一65,52通过分析钉基厚膜应变电阻的隧道势垒模型,提出力敏模型.用BiZO3和RuOZ合成BiZRuZO7并进行试验,发现应变系数随导电相粒径的增大而增大.用力敏模型解释了这一现象,并解释了其他力敏现象,诸如应变系数随势垒高度的增大而增大.图1参10(金)明,镍离子的加入明显改变了聚苯胺膜的形貌;循环伏安,交流阻抗以及恒流充放电等实验表明,聚合过程中镍离子的存在对聚苯胺膜的电容行为有良好的改进作用.从含有0 .2mol/…     

厚膜PTC电阻烧结工艺的研究

研究厚膜PTC电阻的电性能随烧结工艺的变化规律，确定了在不同的烧结制度下的最佳烧结峰值温度。比较了两种烧结工艺条件下烧结的厚膜PTC电阻性能的差异。结果表明：厚膜PTC电阻对烧结温度敏感，随着烧结峰值温度上升，方阻Rs下降，电阻温度系数TCR上升；烧结工艺条件决定了厚膜PTC电阻的电性能，烧结工艺Ⅱ优于烧结工艺Ⅰ。本文运用液相烧结模型对实验结果进行了探讨。     

基于退化数据的厚膜电阻可靠性评估

设计了厚膜电阻的高温贮存试验,以评估厚膜电阻的可靠性。基于阻值的退化数据,采用线性退化模型描述厚膜电阻的退化过程,结果表明,厚膜电阻伪寿命分布满足对数正态分布规律。结合Arrhenius模型推算得出,厚膜电阻在室温下的寿命约为17.8年。分析了厚膜电阻的失效机理,完成了厚膜电阻在温度应力下的可靠性评估。     

厚膜应变电阻的导电机理研究

制备了不同表面电阻率的Ｒｕ基厚膜应变电阻浆料,研究了厚膜应变电阻的表面电阻率与电阻应变系数之间的关系,并对其导电机理与特性进行了分析。     

一种新型BaPbO3厚膜电阻的研究

对具有金属导电性能的BaPbO3的合成进行阐述，确定合成最低电阻率的摩尔配比。以方阻和电阻温度系数为特征参数对BaPbO3厚膜电阻性能进行分析。通过掺银的方法改善厚膜电阻电阻温度系数负值偏大的状况。并提及一个可能的导电模型解释本文中的实验结果。     

厚膜电阻浆料用有机载体挥发特性研究

研究了厚膜电阻浆料用有机载体的挥发特性。模拟厚膜浆料的烘干曲线进行实验,对乙基纤维素为增稠剂的载体系列的挥发特性进行了研究,比较了不同溶剂对载体挥发特性的影响。通过使用混合溶剂,得到了具有层次挥发性的厚膜电阻浆料用有机载体,此载体在添加少量添加剂后表现出良好的使用性能,满足了实际生产的需要。     

厚膜电阻的阻抗与驻波比频率特性的新测量方法

随着电子信息技术和移动通信技术的发展,厚膜电阻的应用越来越广泛。然而,如何准确测量厚膜电阻的阻抗和驻波比频率特性成为了一个难点。建立和分析微带线终端加载厚膜电阻的电路模型,使电阻在电路中匹配,再对应地建立终端短路的电路,最后联合求解出厚膜电阻的阻抗和驻波比频率特性。实测表明,这种测量方法是可行、准确的,对射频厚膜电阻的制造工艺和质量检测有着重要意义。     

Experimental and theoretical characterization of electrical contactin anisotropically conductive adhesive

Electrical conduction through anisotropically conductive adhesive (ACA) is caused by deformation of metal fillers under pressure and heat. In this work, the hardness of the electrical particles under various deformation degrees was determined by nano-indentor measurements and the electrical resistance of the electrical contacts was measured under various deformation degrees. Theoretical model and simulation have been developed for the microscopic mechanism of the electrical conduction through metal fillers in the anisotropically conductive adhesive. By comparing with experimental data it is concluded that the deformation of the metal filler in our ACA is plastic even at rather low external load. Further theoretical simulation reveals two important aspects of the conductance characteristics. The conductance is improved by increasing the external load but the dependence of the conductance on the spatial position of the metal filler becomes stronger. Design and optimization of the ACA with respect to the absolute value of the electric conductance and its dependence on the spatial position of the metal filler are of essential importance for the electronics packaging application of the anisotropically conductive adhesives     

BiFeO3薄膜中的电学输运性质

报道了铁酸铋薄膜样品在80K~300K温度范围直流电学输运性质的研究结果.利用同一前驱体不同老化时间,用化学溶液沉积法在钛酸锶衬底上制备出两种样品.在低阻样品中,低场下电流随电压变化遵从欧姆定律,电阻不随温度变化;而在中等强度外场下显示出肖特基二极管性质.在高阻样品中,低场下电流密度沿晶界分布,输运中的势垒能级为0.57eV;高场下电流的传输则遵从Frenkel-Poole模型,相关势垒能级0.12eV.低阻和高阻两种样品在85K温度下可测最大剩余极化分别为2.6μC/cm2和28.8μC/cm2.     

Modeling the gate bias dependence of contact resistance in staggered polycrystalline organic thin film transistors

We have modeled the dependence on the gate voltage of the bulk contact resistance and interface contact resistance in staggered polycrystalline organic thin film transistors. In the specific, we have investigated how traps, at the grain boundaries of an organic semiconductor thin film layer placed between the metal electrode and the active layer, can contribute to the bulk contact resistance. In order to the take into account this contribution, within the frame of the grain boundary trapping model (GBTM), a model of the energy barrier E_B, which emerges between the accumulation layer at the organic semiconductor/insulator interface and injecting contact, has been proposed. Moreover, the lowering of the energy barrier at the contacts interface region has been included by considering the influence of the electric field generated by the accumulation layer on the injection of carriers at the source and on the collection of charges from the accumulation layer to the drain contact. This work outlines both a Schottky barrier lowering, determined by the accumulation layer opposite the source electrode, as well as a Poole-Frenkel mechanism determined by the electric field of the accumulation layer active at the drain contact region. Finally it is provided and tested an analytical equation of our model for the contact resistance, summarizing the Poole-Frenkel and Schottky barrier lowering contribution with the grain boundary trapping model.     

Size effect on the electrical conduction and noise of RuO2-based thick film resistors

Temperature dependence of sheet resistance for a generic RuO₂-based resistor with a composition of 20wt.% RuO₂-80wt.% glass (63wt.% PbO-25wt.% B₂O₃-12wt.% SiO₂) is evaluated. A combined tunnel/parallel conduction model is employed to describe the resistance behavior with respect to the temperature variation. The geometry of the resistive film, such as the aspect ratio and thickness, cast a significant effect on the electrical characteristic of the thick film assembly. It is observed that shorter resistive films exhibit smaller resistivity as compared to that of the longer film. Thinner resistive films have smaller resistivity as compared to the thicker ones. In addition,1/f noise is the dominating contribution in the thick film resistor. The presence of1/f noise can be qualitatively explained with the aid of the tunneling mechanism.     

Study of the conductance of ultrathin tin diphthalocyanine films

The frequency dependences of the conductance and capacitance of Langmuir-Blodgett tin diphthalocyanine films in vacuum and in the case of adsorption of water molecules were studied. An increase in the film conductance due to adsorption was detected. Possible conduction mechanisms of tin diphthalocyanine in vacuum and water vapor are discussed. The permittivity of tin diphthalocyanine films was estimated from an analysis of the frequency dependence of the capacitance.     

Dipole radiation over an inhomogeneous thin sheet

A general Sommerfeld integral formulation is given for the electromagnetic (EM) fields of an oscillating vertical magnetic or electric dipole over an electrically inhomogeneous thin sheet. The electrical properties of the sheet are characterized by a conductance function that is an arbitrary function of spatial coordinates. When the conductance function has axial symmetry relative to the source dipole, the general solution form simplifies to a Fredholm integral equation of the third kind. The general solution is shown to reduce to the special case of an infinite sheet having uniform conductance. When the sheet conductance is either uniform or varies linearly, the field expressions show an algebraic dependence on the conductance. For a general inhomogeneous conductance distribution, the field dependence is not algebraic     

Influence of Bias-Enhanced Nucleation on Thermal Conductance Through Chemical Vapor Deposited Diamond Films

This work describes an experimental study of the cross-plane thermal conductance of plasma-enhanced chemical vapor deposited (PECVD) diamond films grown as a result of bias-enhanced nucleation (BEN). The diamond films are grown on silicon wafers using a two-step process in which a nucleation layer of amorphous or diamond like (DLC) carbon is first deposited on the silicon under the influence of a voltage bias. Then, conditions are adjusted to allow for polycrystalline diamond (PD) growth. The nucleation layer is essential for seeding diamond growth on smooth substrates and for optimizing PD properties such as grain size, orientation, transparency, adhesion, and roughness. A photoacoustic (PA) technique is employed to measure the thermal conductivities of and the thermal interface resistances between the layers in the diamond film structure. The influence of nucleation layers that are 70, 240, 400, and 650 nm thick on the thermal conductance of the diamond film structure is characterized. The thermal conductivity of the nucleation layer exhibits a thickness dependence for relatively thin layers. For each sample, the thermal conductivity of the PD is higher than 500 Wldrm^-1K^-1 (measurement sensitivity limit). A resistive network for the diamond film structure is developed. The resistance at the silicon/nucleation interface is less than 10^-9m²ldrKldrW^-1 (measurement sensitivity limit), which is of the order of theoretical predictions. The minimum diamond film structure resistance occurs when the nucleation layer is thinnest. When the nucleation layer is sufficiently thick, it begins to exhibit bulk behavior, and the resistance at the nucleation/PD interface dominates the thermal resistance of the diamond film structure.     

钽掺杂的钌基厚膜电阻导电相和玻璃相颗粒尺寸效应的研究

本文报道了钽掺杂钌基厚膜电阻制备过程中导电相和玻璃相颗粒尺寸效应的实验研究结果。当导电相和玻璃相颗粒尺寸分别达到25和50nm时,电阻阻值和电阻温度系数也随之发生显著变化,并尝试根据厚膜电阻导电机理对其产生的原因进行定性的分析。     

Temperature dependence of the electrical conduction in RuO2-based thick film resistors

In this paper, the temperature dependence of resistance of two generic RuO₂-based resistors is investigated. The resistor compositions studied are 80 wt.% glass (63 wt.% PbO - 25 wt.% B₂O₃ - 12 wt.% SiO₂, designated as G1) - 20 wt.% RuO₂ and 80 wt.% glass (55.5 wt.% PbO - 22 wt.% B₂O₃ - 10.5 wt.% SiO₂ - 12 wt.% Al₂O₃, designated as G2) - 20 wt.% RuO₂. The sheet resistance of resistor 80 wt.% G1 - 20 wt.% RuO₂ fired at 850° C decreases as the temperature is increased from 100 K to ∼400 K, remains a minimum value at temperatures 400 K ∼690 K, and then increases as the temperature is further raised. A negative temperature coefficient of resistance (TCR) of ∼-480 ppm/°C is obtained from 100 K to 500 K. TheTCR becomes less negative when temperature increases. Three models for conduction mechanism of thick film resistors are employed to explain the experimental results. A modified model, consisting of both tunneling and parallel conduction approaches, is proposed to elucidate the change in slope in the resistance-inverse temperature curve as well as the temperature dependence of the resistance. In addition, an equivalent circuit model is proposed to describe the electrical behavior of the thick film resistors.