一种低蠕变单组分应变胶的研制

为便于在应变计贴片量少的场合下使用,根据对应变计贴片胶（以下简称应变胶）的性能要求,研制了一种单组分应变胶,其蠕变小,粘接强度高,粘贴工艺简单,贮存期长,完全达到粘贴应变计的使用要求。介绍了应变胶的制备原理、配方和制备工艺。讨论了双酚A型环氧树脂相对分子质量、F-44酚醛环氧树脂用量、聚乙烯醇缩醛用量、固化剂用量、固化条件等因素对粘贴后应变计蠕变和剪切强度等性能的影响。将该单组分应变胶与国内某种双组分应变胶进行了性能对比测试,结果表明,该单组分应变胶具有良好的低蠕变特性。     

贴片胶的选择与使用

贴片胶在SMT混装生产中具有至关重要的作用。贴片胶通常由基本树脂、固化剂、促进剂、增韧剂以及无机填料等组成，其主要功能是保证元器件位置的正确性。目前在组装、焊接过程中用于保持元器件位置及方向的贴片胶，普遍采用的基本树脂有丙烯酸树脂和环氧树脂两种，它们具有各自的优缺点，如表1所示。由于环氧树脂有很好的电气性能，且粘接强度高，故目前使用环氧树脂贴片胶的居多数。     

贴片胶的特性及其应用

主要介绍贴片胶的特性和使用方法，同时还介绍了点胶工艺的一般技术要求．并给出了典型温度曲线。     

MEMS高g加速度传感器封装贴片技术的研究

针对设计的高g加速度传感器,建立封装有限元模型,并利用ANSYS软件仿真分析了贴片热应力及贴片技术对高g加速度传感器性能的影响.分析结果表明,贴片胶的热膨胀系数、弹性模量和厚度是影响热应力的主要因素,同时贴片胶的弹性模量、厚度及贴片胶的量将影响到传感嚣的输出灵敏度.     

贴片胶使用工艺

主要介绍贴片胶的特性,在各种工艺下的使用方法及使用中出现的不良与对策。     

浅谈电子制造行业中的贴片胶涂布工艺技术

主要介绍贴片胶的特性,在各种工艺下的使用方法及使用中出现的不良现象与对策,并给出了典型温度曲线以及温度曲线上主要控制点的工艺参数.     

专利介绍

<正>表面贴装技术用贴片胶CN102 850 948(2013-01-02)。该贴片胶以低黏度液体环氧树脂、潜伏性固化剂、固化促进剂、触变剂、无机填料和颜料为原料,在真空状态下搅拌均匀即可。该贴片胶具有耐高温性优、固化速率快、储存稳定性好、湿强度高、触变性佳、不拉丝和不坍塌等优点,可广泛应用于SMT工艺中。     

专利介绍

<正>一种新型表面贴装技术用贴片胶CN101440266(2009-05-27)。该贴片胶的原料包括环氧树脂混合物、稀释剂、潜伏性固化剂、咪唑类微胶囊固化剂、触变剂、增塑剂、消泡剂、颜料和填     

贴片胶的研发和应用

随着印制线路板(PCB)表面贴装技术(SMT)的高速发展,作为SMT中重要组装辅料的贴片胶越来越受到关注。本文研发的高速点胶用贴片胶,在抗潮、湿强度、拖尾、粘接强度、贮存期等方面都具有优异的特性,在电脑主板元器件高速贴装生产线上应用良好。该胶各项指标均接近甚至超过国外著名品牌,并通过美国相关实验室认证。     

蜂窝夹层结构板-芯脱粘后的修补及对透气性的影响研究

介绍了蜂窝夹层结构板-芯脱粘的注胶修补、挖补和贴片加强方法,分析了不同修补方法对夹层结构胶接质量、强度、重量和透气性的影响。结果表明:两种修补方法配合贴片加强后均可满足结构的胶接质量和设计许用强度要求;采取挖补方法不会影响原有结构的透气性,试件停止抽真空后压力恢复时间不到2 s,且修补增重最小;采取侧向定位注胶修补方法对原有结构4.5 mm高度外的透气性基本没有影响,试件停止抽真空后压力恢复时间约为4 s,但修补增重略大;采取竖直注胶修补方法对原有结构的透气性影响最大,修补区域或有1/3的蜂窝格孔会被胶液完全填充,因此试件停止抽真空后压力恢复时间最长,约为9 s,且修补增重最大。所得结果可为优化产品修补工艺提供参考。     

Some Practical Experiences in Solvent Dyeing

The chief processes for dyeing various fibres in perchloroethylene are described briefly and the factors that determine the design of machinery for using these processes commercially are discussed. The development of machines both of the rotary type and of the circulating-liquor type is described.     

节能环保型干燥设备在炼油催化剂制备及聚合物产品干燥中的应用

针对我国石化行业炼油催化剂及聚合物产品等干燥装置存在的问题,提出了采用节能环保型干燥设备及流程进行技术改造的优化方案,列举了采用优化方案在实际应用中取得的节能减排效果。     

Carbon molecular sieves: production from coal and application in gas separation

Carbon molecular sieves are adsorbents for gas separation processes of increasing importance. A variety of carbonaceous adsorbents, activated carbons and improved carbon molecular sieves, all with different pore size distributions, can be produced, systematically, by using different steps in the manufacturing process. The two types of carbon molecular sieves, CMSN2 and CMSH2, carefully developed by Bergbau-Forschung GmbH, can be distinguished by different separation mechanisms. The procedure of manufacturing the carbon molecular sieves type CMSN2 and type CMSH2 and their application in an air separating process for nitrogen recovery and hydrogen or nobel gas recovery processes, respectively, using different feed gases, is discussed.     

CARBON-BASED MONOLITHIC STRUCTURES

The interest in using monolithic structures for chemical conversion and adsorption processes is increasing. A relatively new type of monolith is based on carbon. The combined favorable properties of carbon and monolithic structures create a support with great potential in catalytic and adsorption processes. This review describes the current state of the art of carbon-based monolithic structures with respect to preparation, obtained support properties, and application in catalytic and adsorption processes, and it evaluates upcoming application areas.     

CARBON-BASED MONOLITHIC STRUCTURES

The interest in using monolithic structures for chemical conversion and adsorption processes is increasing. A relatively new type of monolith is based on carbon. The combined favorable properties of carbon and monolithic structures create a support with great potential in catalytic and adsorption processes. This review describes the current state of the art of carbon-based monolithic structures with respect to preparation, obtained support properties, and application in catalytic and adsorption processes, and it evaluates upcoming application areas.     

酵母细胞连续发酵过程振荡现象的研究进展

振荡现象在连续发酵过程中普遍存在,本文综述了酿酒酵母连续发酵中不同类型振荡现象的研究进展。一类以乙醇连续发酵过程中参数振荡为代表的特殊振荡现象,普遍存在于工业发酵过程,对发酵系统的稳定运行造成不利影响。本文论述了这类振荡现象产生的机理、调控策略的研究进展及其潜在的应用价值。     

Comparison of unsaturated polyester and vinylester resins in low temperature polymerization

Many composite products are produced at low temperatures in processes such as resin transfer molding (RTM), vacuum infusion molding (e.g., Seemann Composite Resin Infusion Molding Process—SCRIMP), and hand lay‐up. These processes are widely used for marine, civil infrastructure, transportation and defense applications. Unsaturated polyester and vinylester resins are two major resins used in these processes due to their low cost, good performance, and processibility. In this study, the reaction kinetics and rheological changes of these two resins cured at low temperatures were studied. Effects of resin type, initiator, promoter, inhibitor and retarder on the reaction kinetics and rheological behaviors were examined using a Differential Scanning Calorimeter (DSC) and a Rheometrics Dynamic Analyzer (RDA). A model was developed to quantify the effects of resin type, temperature, and different curing agents on the gel time for both polyester and vinylester resins cured at low temperatures. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1230–1242, 2001     

On the dependence of the Nernst diffusion layer thickness on potential and sweep rate for reversible and of the thickness of the charge transfer layer for irreversible processes studied by application of the linear potential sweep method

In this paper, a discussion is made of the dependence between the diffusion layer thickness and the potential sweep rate and the potential value for reversible charge transfer processes studied under the application of a linear potential sweep. Also the equivalent circuit for that type of processes is remembered as well as the concept of conductance. The same concepts are discussed for the case of irreversible charge transfer processes studied also by linear potential sweep voltammetry. A consideration is made of the concept of general conductance as utilised in electrochemical processes and the results of its utilisation are compared with those obtained by using the physical definition of conductance and discussed.     

硫磺回收及尾气处理工艺新型流程

针对硫磺回收及尾气处理Claus +SCOT装置存在的问题进行探讨 ,提出采用非在线加热炉并合理利用自身热源的新型简化流程。对新老流程进行了对比 ,指出了新流程设计中应考虑的问题。