贴片电容器失效分析

采用外观检查、金相切片、SEM和EDS分析等手段,通过对贴片电容器失效实例的分析,介绍了对贴片电容器失效的分析过程与方法,得出了内部电极间的陶瓷介质裂纹存在并联电阻特性,这是导致电容器产生漏电失效的主要原因,该裂纹属制造缺陷。失效分析对贴片电容器制造工艺有质量控制作用。     

CL81型高压聚酯膜电容器的阻燃试验

介绍了ＣＬ８１型高压聚酯膜电容器行业标准中关于阻燃试验的技术要求和试验方法。     

钽粉氧含量对其钽阳极漏电流的影响

在多年实践经验基础上，用氧含量Ｘ１（质量分数）０．２０％～０．３８％的四种钽粉，控制钽阳极中残余氧含量Ｘ２（质量分数）在０．０８％～０．２０％间，采用正交设计实验研究了对其漏电流的影响，并建立了漏电流峰值ＩＬ和Ｘ１、Ｘ２间的预示方程，描述了漏电流和钽粉氧含量（Ｘ１）、残余氧含量（Ｘ２）间的关系。随后，用预示方程讨论了钽中氧和钽阳极中残余氧对其漏电流的影响。     

Evaluation of the pole expressions of nano-scale multistage amplifiers based on equivalent output impedance

Several frequency compensation schemes have been proposed to stabilize multistage amplifiers with negative feedback. The performance of these amplifiers can be analyzed by inspecting their input-output transfer function as representation of their frequency response. With many circuit elements affecting the output response, it is relatively difficult to obtain the real transfer function of multistage amplifiers based on only the original small-signal expressions. Instead, certain techniques such as Miller’s theorem are used to approximate important parameters such as DC gain and dominant pole. These methods are not generally helpful for approximating the nondominant poles which have a critical role on the loop stability of nano-scale amplifiers. With this issue in mind, this work proposes a systematic methodology to achieve the pole expressions of multistage amplifiers with frequency compensation. The key in the proposed technique is to model the equivalent impedance of the compensation loop at the output. The effectiveness of the proposed approach has been verified through comparison between the transfer functions obtained from theory and those transfer functions found in the literature.     

CaTiO_3掺杂对BST铁电电容器陶瓷性能的影响

采用固相法制备了CaTiO3掺杂的(Ba0.65Sr0.35)TiO3(BST)陶瓷,研究了CaTiO3掺杂量对BST电容器陶瓷介电性能和微观结构的影响。结果表明:随着CaTiO3掺杂量的增加,BST陶瓷的相对介电常数(εr)先增大然后减小然后增大,介质损耗(tanδ)和交流耐压强度(Eb)先增大然后减小。当CaTiO3掺杂量为摩尔分数10%时,BST陶瓷的综合介电性能较好:εr为4480,tanδ为0.022,Eb为5.8×103V/mm(AC),容温特性符合Y5U特性。     

超级电容电池容量自动检测系统的研究

超级电容电池又叫双电层电容器,是一种新型储能装置,目前国内外对于超级电容电池容量的检测系统自动化程度不高,多数工作由人工控制完成。本文总结了相关蓄电池的自动检测系统,在此基础上提出了适合于超级电容电池的自动检测装置,并通过此装置检测出超级电容电池的常温容量,低温容量以及高倍率放电能力,为今后超级电容电池的自动化检测提供一套可行方案。     

On the Development of Analogue Sampled-Data Signal Processing

This paper provides a historical perspective on thedevelopment of analogue sampled-data signal processing circuitsand systems. The evolution, role and current trends in the developmentof analogue sampled-data signal processing systems is surveyed.Firstly, the evolution of integrated circuit based techniques,culminating in the ubiquitous switched-capacitor technique istraced. Then the role that analogue sampled-data systems playwithin the context of a general information processing environmentis examined and the required characteristics are identified.Trends in silicon integrated circuit processing technology aresummarised and their impact on sampled analogue circuits areidentified. Finally, the application of analogue current-modetechniques, and in particular switched-currents, to overcomesome of the limitations of previous voltage based approaches,is discussed.     

一个新双涡卷电路倍周期分岔到混沌的计算机模拟

本文对一个含分段线性负电容的三阶自治电路的定性性质进行了初步分析,选取一组典型参数进行计算机模拟,找出了超临界Ｈｏｐｆ分岔点及通过倍周期分岔通向混沌的参数区域。     

铁电电容的电极结构

作为铁电电容的电极材料 ,铂是使用最为广泛的金属。在 PZT薄膜的上下两层分别用离子束溅射淀积厚度为 50 nm和 10 0 nm的 Pt。在铂层上按常规工艺需蒸发 1～ 2 μm的 Al作为布线金属。为避免在热处理过程中的固相反应 ,Al/ Pt之间还需嵌入阻挡金属。观察了 Si,Co,Ni,Ti和 Ti/ W合金膜的阻挡特性。实验证明一定组分的 Ti/ W合金膜能有效地抑制 Al/ Pt固相反应 ,获得较为理想的接触特性。     

交流高压介质瓷料

在BaTiO3中适量引入Dy2O3,采用固相法合成(Ba1xDyx)TiO3,外加适量的CuO、MnCO3等添加剂,恰当控制喷雾造粒工艺,试制出交流高压电容器瓷料。利用Dy3+易于晶界或晶界附近分凝并使杂质富集于晶界或其附近,阻止晶界移动,使陶瓷晶粒细化的作用,达到提高陶瓷介质交流抗电强度的目的。大生产瓷料主要性能:er为7 200~ 8 000,tgd为(1.0~1.1)?02,ΔC/C,30℃时为(30~40)%,+85℃时为(50~53)%,交流抗电强度EAC为3.5~4.1 MV/m。