发射装置电接触可靠性设计分析

本文对发射装置中导电零部件电接触可靠性问题进行了分析研究。对影响触柱与电底火接触的主要因素 ,进行了测试、计算、分析 ,指出了在工程设计和使用中降低接触电阻的方法。     

汇流环技术的研究与发展

论述汇流环技术的研究进展。分析了汇流环的主要电性能指标,其中包括接触电阻、绝缘电阻、电介质强度、串扰、电噪声及驻波比等;针对汇流环电接触件结构、电接触材料及零部件制造工艺等方面的研究发展现状分别进行阐述;探讨了汇流环未来的发展方向:小型化、集成化以及向民用领域拓展。     

圆片测试中探针接触电阻的影响与改善方法

介绍了影响探针接触电阻的几个因素,探讨了在测试过程中探针表面的变化以及接触电阻变大的原因、接触电阻对测试的影响。提出了几种控制接触电阻的办法,从材料、探针卡制作方面控制接触电阻的产生,在测试生产过程中通过定期清针、吹氮气等方式减少针尖损耗并减小接触电阻,在测试技术上采用双针开尔文连接和其他一些优化方式避免接触电阻对电参数测试的影响。通过以上方式有效提高了测试准确性和测试过程的顺畅性。     

毛刷电接触对的接触电阻研究

基于R.holm电接触理论建立了毛刷电接触对的接触电阻模型。采用有限元仿真确定了毛刷电接触对在插拔过程中只有弹性变形,并得到了接触电阻模型中的M值为1/2,进行了毛刷电接触对不同插拔深度上的接触电阻试验,通过试验数据拟合确定了毛刷电接触接触电阻模型中的K值为248。进行了毛刷、麻花针、线簧孔接触对在不同插拔深度的接触电阻对比试验,得到了毛刷电接触插拔深度的最优范围为2~2.2 mm,进行了毛刷电接触在2~2.2mm插拔深度时接触电阻寿命试验,基于接触电阻寿命曲线提出了预插拔工艺以提高接触电阻及插拔力的稳定性。毛刷电接触接触电阻研究为毛刷电接触的扩展设计、制造提供了参考。     

金属/半导体接触孔噪声特性研究

通过对1μm金属/半导体接触孔链样品施加高应力的加速寿命试验和室温下的噪声频谱测量,得到了1/f噪声、10Hz点频功率谱特征及其变化规律.实验中发现应力前后1/f噪声10Hz点频功率谱有明显的变化.对比实验中电阻和噪声的变化,噪声变化量是电阻变化量的1304倍.1/f噪声可以作为金属/半导体接触孔可靠性的灵敏表征参量.     

电子机械元件可靠性及寿命的电接触现象测试方法

电子元件的可靠性及使用寿命非常重要。在这方面虽然作了某些研究,但看来还不能引起人们足够的重视。事实上,电子机械元件的可靠性及使用寿命是很重要的,甚至要比电子元件本身更为重要。可是电子机械元件和电子元件和电子元件间存在很大的差异,因为电子机械元件的电接触现象有其专门的特性。要明确表示电子机械元件的可靠性等级及其使用寿命,接触电阻现象是一个重要的因素。为了了解接触电阻现象的特性,我们应说明研究那些与电子元件的可靠性及电阻现象特性是相当困难的。我们通过显示的接触特性之间联系的例子之后就可以订出电子机械元件的可靠性及其使用寿命的定义。其次我们来描述一下如何使用随机循环抽验法来估计出电子机械元件的可靠性等级及寿命的期限。预计电子机械元件的可靠性和寿命采用随机循环抽检法要比用恒定循环试验法更为实际可行。因此我们提议将用一套采用微型计算机的随机循环试验方法测试系统来测试元件可靠性及寿命的正确数值,不但适用于电子机械动态元件、也适用于机械静态元件。     

电缆连接器组件初级电学性能检验

不论是高频电连接器，还是低频电连接器，接触电阻（直流电阻）、绝缘电阻和介质耐压（又称抗电强度）都是保证电连接器能正常可靠地工作的最基本的电气参数。这三个检验项目也是用户判别电连接器质量和可靠性优劣的重要依据。[第一段]     

大电流密度下欧姆接触退化机理的研究

对大电流密度下欧姆接触的结构进行了改进,采用只对接触区域老化而其它区域非破坏性的结构特点,保证测量数据的真实有效性。工艺制备中采取多次SiO2铺垫多次光刻技术解决了引线电极断裂的可能。通过施加达到或超过105A/cm2电流密度,利用文中结构测得比接触电阻早期快速失效,且随电流密度增加退化加剧,对样品老化前后进行能谱分析得知,大电流密度下接触层中Al离子发生了扩散从而破坏了良好接触。     

电接触材料锡及其合金镀层

为了保证锡及其合金镀层在电接触表面能无故障、有效和安全可靠地接触,就必须清楚地了解锡及其合金镀层作为电接触表面材料的特性和特征;同时,还应考虑锡及其合金镀层在电接触表面的使用功能、使用条件和使用环境.实践证明:锡及其合金镀层的电接触表面只要与电接触表面润滑保护材料如LP-38T或SP-32T等有效地配合使用就可以更为合理地配置、利用和节约有限的贵金属自然资源,就能使人类社会达到持续、稳定和文明地向前发展.     

弹片连接的弱力接触电阻测试与分析

弹片作为一种重要的电连接器,它的可靠性会直接影响设备的电性能。研究弹片电连接的规律和影响因素,对于提升设备性能并节约成本具有重要意义。本文通过软件仿真及实验测量,测试了在弱外加力(<2 N)的条件下,以弹片为代表的电连接部件,接触电阻阻值随着接触金属面材料的电阻率减小而减小,且随着外加力的增大而减小的规律。通过机械接触理论分析及计算,验证了接触电阻会受到材料的电阻率与外加力影响;对弹片的接触电阻产生机理给出了明确解释,能够更准确地判断弹片与不同接触界面产生接触电阻的大小关系。     

接触效应对小型半导体温差发电器性能的影响

针对小型半导体温差(TEG)发电器中接触热阻和接触电阻的影响进行了分析研究.结果表明,接触热阻和接触电阻只在2mm以内的电偶臂长度内有明显影响;在电偶臂长度小于1mm时,输出功率和热电效率均有一个急剧上升的变化阶段;当长度超过5mm后,输出功率和热电效率均趋于定值;在冷热端温度分别为283和383K,Z=0.0024K-1、电偶臂长为2mm、接触热阻比0.2和接触电阻比0.1条件下,热电功率约为4mW/mm2,热电效率约为3.5%,而理想无接触热阻和电阻的热电效率约为4.2%.由此可知,半导体温差发电器中接触热阻和接触电阻的影响不可忽视.     

Processability and reliability of nonconductive adhesives (NCAs) in fine-pitch chip-on-flex applications

The use of NCAs to form direct contact interconnections between chip bumps and substrate pads have become a viable option in interconnection technology for fine-pitch applications. However, the primary concerns with NCAs are their long-term reliability, stability, and consistent electrical performance in particulate interconnections. Results of assembly process studies and environmental testing using NCAs on flexible substrates are analyzed and discussed herein. An extensive design experiment was performed to determine which process parameters were critical in obtaining good electrical connections. A reliability evaluation of NCAs for flexible substrate applications was carried out to gain more insight into the failure mechanisms of this type of interconnect. Pressure cooker test results showed that failures occurring in NCA joints are primarily due to moisture absorption, which could lead to interfacial delamination at the substrate/adhesive interface, accompanied by hygroscopic swelling. NCAs with lower coefficients of thermal expansion also exhibited better contact resistance stability during high-temperature storage tests.     

一种腔体滤波器悬臂螺旋振子的抗冲振优化设计

针对大功率腔体滤波器螺旋振子刚度小,在载机环境条件下特性响应曲线不稳定的问题,提出了一种螺旋振子的抗冲振创新设计思路与方法.通过铝材铣制成梯形截面螺旋振子增加其刚度,采用对称局部环抱的异形结构件对悬臂螺旋振子进行加固以提高抗冲振能力.优化设计后的振子顺利通过载机环境试验考核和电性能指标测试.该设计方案已成功应用于大功率跳频滤波器设备中,效果良好.     

Research on the contact resistance,reliability, and degradation mechanisms of anisotropically conductive film interconnection for flip-chip-on-flex applications

Although there have been many years of development, the degradation of the electrical performance of anisotropically conductive adhesive or film (ACA or ACF) interconnection for flip-chip assembly is still a critical drawback despite wide application. In-depth study about the reliability and degradation mechanism of ACF interconnection is necessary. In this paper, the initial contact resistance, electrical performance after reliability tests, and degradation mechanisms of ACF interconnection for flip-chip-on-flex (FCOF) assembly were studied using very-low-height Ni and Au-coated Ni-bumped chips. The combination of ACF and very-low-height bumped chips was considered because it has potential for very low cost and ultrafine pitch interconnection. Contact resistance changes were monitored during reliability tests, such as high humidity and temperature and thermal cycling. The high, initial contact resistance resulted from a thin oxide layer on the surface of the bumps. The reliability results showed that the degradation of electrical performance was mainly related to the oxide formation on the surface of deformed particles with non-noble metal coating, the severe metal oxidation on the conductive surface of bumps, and coefficient of thermal expansion (CTE) mismatch between the ACF adhesive and the contact conductive-surface metallization. Some methods for reducing initial contact resistance and improving ACF interconnection reliability were suggested. The suggestions include the removal of the oxide layer and an increase of the Au-coating film to improve conductive-surface quality, appropriate choice of conductive particle, and further development of better polymeric adhesives with low CTE and high electrical performance.     

Contact Resistance in Organic Field‐Effect Transistors: Conquering the Barrier

Organic semiconductors have sparked interest as flexible, solution processable, and chemically tunable electronic materials. Improvements in charge carrier mobility put organic semiconductors in a competitive position for incorporation in a variety of (opto‐)electronic applications. One example is the organic field‐effect transistor (OFET), which is the fundamental building block of many applications based on organic semiconductors. While the semiconductor performance improvements opened up the possibilities for applying organic materials as active components in fast switching electrical devices, the ability to make good electrical contact hinders further development of deployable electronics. Additionally, inefficient contacts represent serious bottlenecks in identifying new electronic materials by inhibiting access to their intrinsic properties or providing misleading information. Recent work focused on the relationships of contact resistance with device architecture, applied voltage, metal and dielectric interfaces, has led to a steady reduction in contact resistance in OFETs. While impressive progress was made, contact resistance is still above the limits necessary to drive devices at the speed required for many active electronic components. Here, the origins of contact resistance and recent improvement in organic transistors are presented, with emphasis on the electric field and geometric considerations of charge injection in OFETs.     

高空飞行器供油驱动系统IGBT模块结温特性研究

对高空飞行器供油驱动系统在特定负载状态下的IGBT模块结温特性进行研究。高空飞行器对供油驱动系统的高功率密度要求高及环境散热条件差的状况,使得其关键部件IGBT模块在功率裕量与结温控制方面更为严格。根据负载特性精确计算结温,对于在特定散热条件下系统的可靠运行非常重要。运用非稳态导热的Foster集总参数法,分析IGBT模块点热源特性及其他热源对计算影响,建立一种含校正系数的热网络模型,并在短时脉冲过载及输出低频两种特有状态下,对IGBT模块的结温特性进行分析。通过对高空飞行器飞行过程中IGBT模块结温特性的计算,结合仿真软件Semisel的对比分析,验证了建模和分析本文所提方法的有效性。     

温差电器件接触电阻和接触热阻的测试及分析

接触电阻和接触热阻是影响温差电器件性能的两个重要的工艺参数，直接反映器件制造的工艺水平。因此，对器件的接触电阻和接触热阻进行测试分析，将能够定量地了解现行工艺对器件温差电性能的影响程度。本文首先介绍接触电阻的测试方法和实验结果，然后利用所测的数据，再通过对器件输出功率特性的测试，间接地导出器件的接触热阻。据笔者所知，这是温差电器件接触热阻实测数值的首次报道。     

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。