锆铝吸气剂在内腔式He-Ne激光器中的应用

吸气剂在真空技术中是相当重要的。它可以吸收电真空器件在封离后内部构件放出的残余气体以及微小漏孔渗进的外部杂气,维持器件的真空度,提高器件的寿命。 吸气剂有蒸散型(如钡类吸气剂)和非蒸散型两种。武汉地震大队等单位曾在He-Ne管中使用过蒸散型的钡类吸气剂。钡类吸气剂的缺点是钡膜常在激光管内升华和爬迁,容易引起极间漏电、污染阴极和膜片,对外观也有影响。     

电子管以及灯丝型和放电型灯泡中的真空与吸气问题

本评论中,根据结构和制造技术,描述并讨论了电子学中残余气体引起的问题,以及灯热型和放电型灯泡中多余气体的问题,摘要阐述了电子学中残余气体的各种来源,附带有为克服这些气体的有害影响而使用吸气剂的概念性说明。略述了钡和非蒸散吸气剂之间的基本差异。注意到白炽灯和高压以及低压放电灯中多余气体的有害影响,但着重于荧光灯中的气体问题。指出了每一类型灯泡的合理的吸气技术,其中包括荧光灯用的兼有吸气剂和汞释放剂的新型装置的说明。最后,简单比较了在真空电子学和充气灯两者之间气体分析的基本差异。     

冷阴极管中吸气剂的应用

本文重点介绍在金属陶瓷盘封结构的冷阴极真空触发管中使用非蒸散型间热式锆石墨吸气剂时,如何选择吸气剂表面积,怎样安装以及加热激活等问题。     

锆钒铁消气剂在行波管中的应用

本文介绍一种低温激活具有室温条件下较大吸气能力的新型非蒸散式消气剂在行波管的应用,对改善管内真空气氛延长行波管使用寿命起了重大作用。     

非蒸散型吸气剂激活的研究

用χ-射线光电子能谱(XPS)和视线残余气体分析(line of sight residual gas analysis—LOSRGA),对数个非蒸散型吸气剂的激活作了研究。正如人们所知,XPS或ESCA技术,常用来探视表面的化学变化,而LOSRGA技术,常用来确定放出气体的类型和相对数量。所研究的吸气剂。据称是锆的金属粉末与石墨的混合物,内嵌一个(?)绕热供间接加热用。根据制造厂家提供的加热电流对温度的关系曲线,确定吸气剂的激活温度。本文提供的数据记录表明,吸气剂的激活产生一种近金属性的Zr表面。所释放的气体主要是H_2,也释放一些H_2O、CO和CO_2。吸气剂同气体生成稳定的化合物,如ZrO_2、ZrH_2、ZrC等。这可以从XPS谱线的变化观察到。在此之前,吸气剂继续保持活性。     

抽除活性气体的SORB—AC泵

SORB—AC泵是一种利用非蒸散吸气材料来着活性气体的新型真空泵。吸气材料为ST101锆—铝合金。ST101合金是十年来深入研究非蒸散吸气的材料的成果。 同时,这种合金材料的实用产品——非蒸散吸气剂褶带,也已研制成功。 ST101合金被在窄长的金属条上,然后将金属条按手风琴式样褶叠起来,并将褶叠带圈成圆柱形,做成吸气剂泵褶带。 被复杂的基体材料可以是铁或磁合金。 吸气剂泵头褶带组装在具有中心加热器的上。 然后可将泵头褶带赤裸地组装在真空室的里边,或者安装在与真空室相连的套壳里。 两种泵者发用标准的超高真空法兰盘。 与升华泵所采用工艺规范不同,这种泵的抽气工艺规范不涉及到吸气材料蒸散成膜的问题。 在非蒸散吸气剂中,活性气体都被吸着在吸气材料的第一颗粒表面上。     

现代吸气剂及其应用技术

近年来，新型叹气剂的开发和应用均取得长足的进步。吸气剂在真空技术领域内愈加显示出它的重要性。本文介绍了吸气剂的吸气机理，吸气材料对氢及其同位素之间的吸附、解吸的平衡理论问题，蒸散型吸气剂和非蒸散型吸气剂的最新发展和应用等．     

吸气剂激活与再生的机理

一、吸气剂的吸气三因素 吸气剂的吸气是一个复杂的物理的和化学的过程。例如,吸气剂蒸散时金属蒸汽与气相分子的碰撞;气相分子与蒸散薄膜,菲蒸散吸剂表面之间物理的和化学的作用;以及吸附相分子(或原子)在吸气剂内部的扩散、渗透和固溶等等,都是造成气体被吸着的原因。通常认为,吸气剂的吸气大致有三个主要的,并且互相联系的作用因素:蒸散吸气(非蒸散吸气剂除外);气相分子的表面吸附(物理吸附和化学吸附);吸附相分子(或原子)的扩散(表面扩散和体扩散)。     

MEMS器件真空封装工艺研究

MEMS器件的真空封装是整个工艺过程中的难点,封装的质量决定着整个器件的质量和使用寿命。现有的封装工艺,封装后器件内部真空度不能有效保持,是需要在真空下工作的器件的瓶颈。随着吸气剂的广泛使用,使MEMS器件的真空度保持能力大大提高,但现有的封装工艺设备不能满足吸气剂的激活条件。分析了空气阻尼对MEMS器件品质因数的影响,提出一种将现有的真空共晶设备的改进方法,使之能应用于使用吸气剂的MEMS器件的真空封装工艺。     

ZrAl_(16)非蒸散消气剂的吸气性能

在我们的实验条件下,对国产ZrAl_(16)非蒸散消气剂的吸气性能作了试验。测得在高真空范围内,在压强为1×10~(-5)托,温度为740℃时,对空气的比抽速为360厘米~3/秒厘米~2;在低真空范围内,在压强10~(-2)～10~(-3)托下,温度为750℃时,对氮气的比抽速为180厘米~3/秒厘米~2;对氮气的吸气容量大干24厘米~3托/厘米~2;起动压强为0.5托左右。实验表明,消气剂颗粒粉的性质,吸气时的工作温度,激活情况等对比抽速都有较大的影响。并表明ZrAl_(16)合金粉以镍作底金属,在运用温度超过60℃时,因高温烧结引起再结晶,破坏了它的吸气性能。文中对ZrAl_(16)消气剂的吸气机理也给予了一定的物理解释。摸索了消气剂粉的涂复方法,得到了粉层和底金属有比较牢固结合的方法,即机械滚轧式的涂复方法。由此可作出大面积的涂复消气剂,可装配成消气泵,作为无油机组的一个组件。ZrAl_(16)具有的卓越性能,可相信将广泛地用于电真空器件制造工业,并用于高能加速器,受控热核反应等其他领域。     

Titanium-Based Getter Solution for Wafer-Level MEMS Vacuum Packaging

Ultrahigh-vacuum conditions can be achieved by employing porous absorbent materials such as Ti, Zr, Ta, and Yt. Commercial getters are primarily Zr-based, since Zr possesses the best adsorption characteristics. Titanium is not considered as a candidate, since adsorption of gases by Ti is significantly reduced due to oxidation and other contamination. In the present work, it is demonstrated that the adsorption property of Ti can be substantially enhanced and benchmarked against other Zr-based commercial getters by employing a sacrificial layer such as Ni over Ti, and also by using other surface engineering techniques. It has been confirmed that, in addition to the activation temperature, the vacuum level during getter activation also plays a pivotal role in influencing the adsorption characteristics of Ti. It has been determined that the getter life could be significantly improved by the reversible adsorption characteristic of H₂ gas, facilitating regeneration cycles.     

MEMS封装中的封帽工艺技术

MEMS封装技术大多是从集成电路封装技术继承和发展而来,但MEMS器件自身有其特殊性,对封装技术也提出了更高的要求,如低湿,高真空,高气密性等。本文介绍了五种用于MEMS封装的封帽工艺技术,即平行缝焊、钎焊、激光焊接、超声焊接和胶粘封帽。总结了不同封帽工艺的特点以及不同MEMS器件对封帽工艺的选择。本文还介绍了几种常用的吸附剂类型,针对吸附剂易于饱和问题,给出了封帽工艺解决方案,探讨了使用吸附剂、润滑剂控制封装内部环境的方法。     

The use of titanium metal in vacuum devices

The excellent gettering and gas retention properties of titanium metal make it highly suitable for use in vacuum devices. Tiny receiving tubes made with titanium parts are described which are capable of operating at high cathode emission densities. These high densities reduce the electron transit times and give better high-frequency performance. They permit the use of small electrodes and reduced heater and plate input powers. Vacuum devices made with titanium and ceramic parts can be operated for long periods of time at temperatures up to 700°C.     

Subjective validation methods for analog integrated circuits’ metamodels using graphical displays of data

Metamodels are approximations to simulation models. They are built and validated using simulation results for samples of data points in the design variables space. Metamodels are more efficient to run compared to the simulation models they represent. They are validated to substantiate their accuracy using objective and/or subjective techniques. Objective validation methods based on various statistics such as root mean square RMS errors are often used. These methods require that certain statistical assumptions be satisfied by the data used in validation. Subjective validation methods are used, in particular, when some of these statistical assumptions are violated; for example, if the number of data points used is not sufficient. This paper presents and compares six different plot types that can be used to display data for subjective validation of metamodels, and demonstrates their usefulness as validation tools for analog circuits’ metamodels. These plots are easy to generate, using metamodel and simulation data. Furthermore, these methods are general and require no statistical assumptions for the data that can be displayed.     

A process for making clean gas discharge tubes

Tube assemblies of forsterite ceramic and titanium are outgassed and then sealed together with reactive alloys in an atmosphere of the noble gas with which they are to be filled. The gettering action of the hot titanium results in a very pure gas filling. Examples of gas tubes constructed by this new process include voltage regulators, voltage reference tubes, thyratrons, and spark gaps. This method of making ceramic-metal seals in an inert atmosphere may be applied to the production of ceramic-metal sub-assemblies and tube types that do not require gas filling or evacuation at the time of assembly. The fact that a vacuum system is not required to make these seals, and that the cooling time is shorted by convection currents, results in simplification of equipment and reduction of expense and should extend the usefulness of this type of ceramic-metal sealing.     

Diffusion and absorption of corrosive gases in electronic encapsulants

Plastic encapsulated microcircuits with aluminum triple track structures were exposed to mixed flowing gas conditions to simulate and accelerate possible environments during long-term storage. No increase in resistance was measured and no corrosion products were observed after 800 h of accelerated exposure. Further experimentation indicated that chloride gas reacts with surface moisture in microscale and macroscale voids within the encapsulant, creating chloride ions. These ions become strongly bound to ion getters present in the epoxy molding compound, trapping the chloride ions within the bulk encapsulant and effectively retarding the diffusion process, which could lead to corrosion at the surface of the die.     

吸气剂在行波管中的应用

本文介绍了目前行波管所使用的锆-石墨、锆-锫钒铁、钼-钛吸气剂,以及近年来使用吸气剂所发现的问题,同时介绍了应用于行波管吸气剂的新技术及发展趋势.     

共晶焊料焊接的孔隙率研究

大功率或高功率密度的高可靠集成电路等通常采用合金焊料焊接芯片,以降低封装热阻和提高芯片焊接的可靠性。合金焊料焊接方式主要有真空烧结、保护气氛下静压烧结、共晶摩擦焊等。不同焊接工艺有其不同的适应性和焊接可靠性。文章以高可靠封装常用金基焊料的共晶焊接为例,探讨在相同封装结构、不同共晶焊接工艺下焊接层孔隙率,以及相同工艺设备、工艺条件下随芯片尺寸增大孔隙率的变化趋势。研究结果表明:金-硅共晶摩擦焊工艺的孔隙率低于金-锡真空烧结工艺和金-锡保护气氛静压烧结;同一焊接工艺,随着芯片尺寸变大,其孔隙率变化不显著,但单个空洞的尺寸有明显增大趋势。