采用阳极屏蔽提高电镀厚度均匀性

在不改变电镀工艺参数及电镀设备的条件下,利用阳极屏蔽,提高印制板镀铜厚度均匀性。     

Ni层厚度对p-GaN/Ni/Au欧姆接触特性的影响

对p-GaN/Ni/Au欧姆接触特性与Ni金属层厚度之间的相关性进行了对比实验研究,利用XRD衍射结果与表面金相显微分析手段对Ni/Au双层金属电极在合金退火过程中的行为特性进行了细致探讨。分析结果表明:在Ni/Au电极结构中,由双层互扩散机制与NiO氧化反应机理决定,Ni层与Au层之间的厚度比率对p型GaN欧姆接触特性的优劣有重要影响,在Ni、Au层厚度相当时可获得最佳的p型欧姆接触。     

多变量单值控制图在电镀零件镀层厚度统计控制方面的应用

电镀零件的质量状况好坏会严重影响微波管的可靠性.本文运用多变量单值控制图法对微波管生产过程中零件镀层厚度进行统计控制,判断零件电镀是否处于统计受控状态,为进一步采取工程措施提供依据.     

各种镀层厚度不同图形双面电镀的可行性研究

根据晶圆电镀原理,建立简化的晶圆双面电镀槽模型,分析了改变阴阳极间距对电流密度的影响,探索了各种镀层厚度不同图形双面电镀的可行性。     

浅谈多层埋／盲孔厚铜板的厚度控制

简要概述了带有埋/盲孔厚铜箔多层印制板制作过程中的厚度控制要点和方法。     

聚酰亚胺薄膜厚度均匀性分析

聚酰亚胺薄膜(Polyimide Film),简称PI薄膜,是世界上最好的绝缘类高分子材料,本文简单论述了聚酰亚胺薄膜的生产工艺,并重点分析了厚度均匀性对薄膜力学性能、电气性能的影响以及测试和改进方法。     

化学镀Ni层中的添加剂对焊料接合可靠性的影响

概述了化学镀镍层中的微量添加剂(PDIS)浓度对化学镀Ni/Pa/Au镀层的析出速度、耐蚀性、焊料湿润性和焊料接合可靠性的影响。     

涡流技术在检测钢件淬火层厚度中的应用

涡流检测实质上就是通过运用法拉利电磁感应定律来反映金属导电材料表面缺陷和厚度变化。文章主要研究电涡流检测钢件淬火层厚度时表面阻抗的变化,通过阻抗变化来反映淬火层厚度的变化,经过数据处理得到待测钢件的厚度。由于在电涡流测厚传感器设计过程中会受到多种因素的干扰,对测量精度和可靠性有很大的影响,这里也对主要的干扰因素进行了推导和分析,通过对标准涂层试块进行测量和对数据的分析,能够大略的反映出淬火层厚度的变化。     

PCB镀层厚度控制的必要性

概述了PCB的电性能,应用电镀法制造的多层板和工艺,特性阻抗的整合和变化因素,以及镀层控制和可靠性。     

基于NDIR的塑料薄膜厚度在线检测系统

为了快速、精确的在线测量塑料薄膜厚度,提出了一种基于NDIR的塑料薄膜厚度在线检测技术,此技术改进了现代近红外测厚方法中常采用的双单色红外光对比法,使用单光源简化了双光源调制的难度,优化了由于双光源照射薄膜不同位置带来的准确性问题。应用上述技术设计实现了此检测系统,此系统应用NDIR相关技术,将现代数字信号处理方法用于数据处理过程中。通过实验方式得到测量结果,并对测量结果进行了数据分析和误差统计,实验结果表明,此系统具有精度高,稳定性可靠等优点,值得推广。     

Cladding Layer Impedance Reduction to Improve Microwave Propagation Properties in p-i-n Waveguides

The cladding layer effect on microwave propagation properties of semiconductor p-i-n waveguides is investigated in this letter. Through the optical excitation in quantum wells of p-i-n waveguides, high-speed photocurrent is used to examine the microwave propagation. Two devices of p-i-n waveguides with different cladding layers are fabricated and measured, showing that a higher speed is found in the waveguide of wider cladding width. Verified by the microwave propagation properties, the higher speed is mainly attributed to lower microwave propagation loss due to the lower impedance in the wider cladding layer, suggesting this kind of structure can be applied to high-speed waveguide-based devices     

On Spurious Outputs from High-Power Pulsed Microwave Tubes and Their Control

Excessive spurious outputs from high-power pulsed magnetrons, klystrons and traveling-wave tubes can cause intolerable interference and deleterious effects in a high-power microwave system. The harmonic output from a klystron may vary appreciably with changes in operating conditions. Harmonic outputs from tubes cannot be eliminated but their radiation can be significantly reduced by using filters. If the parasitic or spurious oscillations are very strong, adverse effects such as amplitude and phase instability of the fundamental frequency output may occur. Some of the spurious outputs may be reduced or eliminated by redesign of the tube or its modulator.     

高频钎焊在微波电子管中的应用

微波电子行波管的高频系统往往要采用结构复杂的不锈钢零件，为解决这些零件常规钎焊工艺条件下存在的润湿性差、生产周期长以及不适于批量生产的问题，本文采用了冲击镀镍-高频钎焊的新工艺。实际应用表明，采用这一工艺，不仅较好地解决了不锈钢表面的润湿问题，而且焊接过程工艺简单、快捷。这一工艺已成功应用于产品的批量生产。     

材料是保证微波电子管制造的决定因素

微波电子管设计与制造过程中合理选用材料，除了解材料的电性能、热性能、真空性能外，还要对材料的综合机械性能、物理和化学性能均有较高的要求。材料的性能是微波电子管的质量、可靠性、安全性和发展的决定性因素。     

微波管器件现状及技术发展分析

综述了国内外几种主要的微波真空功率器件技术的发展现状,特别对微波管CAD技术、短（亚）毫米波器件、阴极技术等进行了分析,并对整个微波管行业面临的挑战和机遇进行了讨论。     

大功率微波真空电子器件的发展及应用

本文给出了大功率微波真空电子器件的发展及应用情况。海湾战争证明,微波管仍然是现代军事电子装备的关键器件,其性能的不断改进,大大增强了电子战和雷达系统的成力。真空微电子技术和相对论电子学为微波真空电子器件的发展,奠定了更为广阔的基础。     

Sn-Cu Intermetallic Grain Morphology Related to Sn Layer Thickness

Tin is widely used as a coating material for copper metal in the electronics industry where tin whisker growth is a concern because it affects the reliability of electronic devices. Because whisker growth reduces joint reliability, it is important to monitor the growth of Cu₃Sn and Cu₆Sn₅, which is usually done by using an X-ray diffraction method to estimate the thickness of the tin layer. In this study, we use the sequential electrochemical reduction analysis (SERA) technique to measure the thickness of layers of pure tin, Cu₆Sn₅, and Cu₃Sn. We also discuss the depletion rate of tin layers at high-temperature aging and the growth of these intermetallics.     

Quality-Control Practices in Lead-Acid Battery Manufacturing to Improve Quality, Cost, Reliability

This is a case study on the diagnosis of quality problems in a lead-acid battery plant. The study demonstrates the effectiveness of integrating statistical quality assurance programs with process and production control methods in improving the overall performance of the plant. It asserts that quality control is an integral part of process and production control methods. Process and production control methods had to be characterized in order to discover the correction needed for improving quality. The salient features of the study include: * adoption of operating schedules which maintain steady production * application of statistical quality control tools to monitor and direct trends in quality parameters * use of quality circles for diagnosing quality problems * the efficacy of simple devices for dissemination of quality standards to all production staff by posting specification control charts. Several quality improvements were achieved by paying attention to manufacturing process details rather than by sophisticated research methods. The outcome of the study led to reducing scrap and rework as well as improving battery performance and reliability in the field.     

Exact Analytical Solution for the Critical Layer Thickness of a Lattice-Mismatched Heteroepitaxial Layer

Based on the Lambert W-function, an exact analytical solution for the critical thickness of a lattice-mismatched heteroepitaxial layer is presented. The new expression in exact and algebraic closed form eliminates the need for complex iterative computation. Its high accuracy is proved by comparison of the calculated critical thickness versus fractional atomic content of an alloy epilayer with the respective numerical solution.     

薄膜SOI结构中反型层厚度与薄膜厚度的关系

本文从理论上分析了薄膜SOI结构中反型层厚度与薄膜厚度的关系。为设计薄膜MOS/SOI器件引进了一个新的参数──薄膜整体反型临界厚度。分析认为,为使超薄膜MOS/SOI器件高速和高功率工作,有必要使薄膜厚度接近整体强反型临界厚度。