高热导率银粉导电胶在LED照明中的应用及前景

高热导率银粉导电胶是近几年为适合大功率高亮度LED封装用而研发的新型产品。介绍了高热导率银粉导电胶在LED照明中的应用现状及市场情况,以及影响银粉导电胶导热性能的主要因素、提高其导热性的途径,并对导热银粉导电胶的发展前景进行了展望。     

导电胶的研究新进展

介绍了近年来发展迅速的几种典型的导电胶(如纳米导电胶、复合导电胶、紫外光固化导电胶和无导电粒子导电胶等),阐述了导电胶可靠性研究中环境影响试验的研究现状,展望了今后导电胶的应用前景和发展方向。     

铜粉导电胶研制成功

近些年来,导电胶粘剂在微电子封装、组装行业中得到了广泛应用,目前仍以添加型导电胶占据主导地位。在各种导电胶中金粉导电胶性能最佳,但价格昂贵,应用受限;银粉导电胶效果很好,不过存在着电迁移等弊端,价也很高;铜粉导电胶的导电性能基本接近银粉导电胶,价格便宜,却因铜粉极易氧化而影响导电性能。东北大学材料与冶金学院采用硅烷偶联剂（KH-550）对铜粉进行改性处理,提高了其在导电胶中的分散性、使用过程中的抗氧化性和粘接强度。还将甲醛作为还原剂加入到树脂中,     

关于254—2铜粉导电胶的室内自然老化性能

有许多资料[1-3]认为,可以用铜粉作为导电胶的导电介质,但同时又认为,铜粉的氧化问题难以解决。所以,至今在世界上只有少数国家有铜粉导电胶[4,5],而且历史也不长,资料甚少,因而人们对铜粉导电胶认识不深。254—2铜粉导电胶问世以夹,已在一些刊物中作了介绍;但其应用不够广泛,只有一些新开发的产品采用铜粉导电胶。对铜     

导电胶的应用现状

介绍了导电胶的组成、分类、国内研究及应用现状,展望了导电胶的发展方向。     

环氧树脂导电胶的研究现状

环氧导电胶是代替Sn/Pb焊料的一种胶黏剂,与传统的Sn/Pb焊料相比,环氧导电胶具有粘接温度低、可控性好、分辨率高、工艺简便以及环保等优点。近年来,科研工作者积极地研发高性能、多功能以及低成本的新型导电胶,以满足不断发展的市场需求。环氧导电胶作为一种新型的复合工业材料,具有巨大的发展潜力以及广阔的应用前景。阐述了影响环氧导电胶黏剂性能的因素以及高性能环氧导电胶的研究状况,并对环氧导电胶黏剂的未来发展作了展望。     

导电胶的研究与应用

新型复合材料导电胶自被发现可用于代替焊接以来,研究者就在研究可用于不同领域内的导电胶,此文对导电胶的组成以及各组份的作用做了简单介绍,根据其组份对其进行不同的分类;并对其导电机理进行了探讨.相对焊接,导电胶具有的成本低、效果好的优点因而具有较好的市场,但当前市场中的各类常用导电胶都存在一定的缺陷,通过大量的研究实践,就针对其问题提出了一些解决办法.最后对导电胶在市场的应用状况也做了简要介绍.     

导电胶的应用现状

介绍了导电胶的组成、导电机理及在各方面的应用,并对未来导电胶的发展作了展望。     

碳系导电胶的研究进展

介绍了导电胶的种类,重点综述了碳系导电胶[如导电炭黑导电胶、石墨导电胶、碳纳米管(CNTs)导电胶、石墨烯导电胶和碳纤维导电胶等]、复合导电胶(如Ag/CNTs导电胶、Ag/石墨烯导电胶等)的研究进展。最后对碳系导电胶的研究方向进行了展望。     

电磁屏蔽用导电硅胶的固化动力学研究

为导电胶的应用工艺提供基础,有必要研究导电胶的固化行为。本文采用动态热机械性能测试法（DMA法）,针对不同配比的有机硅导电胶进行了非等温固化特性考察,主要针对储能模量变化曲线,利用Kissinger方程、Crane方程和Ozawa方程分别计算出了有机硅导电胶的固化活化能、反应级数等固化反应动力学参数,为电磁屏蔽用导电硅胶的制备和应用提供了基础数据。     

无铅化微电子互连技术与导电胶

介绍了电子互连用导电胶(ECA)的组成和基本性能,综述了ECA在电学性能、力学性能和稳定性等方面的研究进展。随着世界范围内含铅材料的限制和禁止使用,电子制造过程中的无铅化已成为该领域的发展方向和必须面对的挑战。ECA是替代含铅钎料、实现微电子互连技术无铅化的重要发展方向。虽然目前ECA仍存在着电阻率偏高、易老化失效和电流通过能力偏低等问题,但是高性能树脂和新型导电填料的不断涌现,将为ECA性能的提高提供新的解决途径和方法。     

聚氨酯/镀银纳米石墨导电胶的制备与性能研究

以聚氨酯(PU)预聚体为基体,以镀银纳米石墨为导电填料,采用共混法制备PU/镀银纳米石墨导电胶,并与PU/纳米石墨导电胶进行电学性能、力学性能和热稳定性能对比。结果表明:PU/镀银纳米石墨导电胶和PU/纳米石墨导电胶的导电渗流阈值分别为3%和9%,此时对应的电导率分别为0.044 S/cm和0.012 S/cm;前者的力学性能(最大剪切强度为5.76 MPa)高于后者(最大剪切强度为3.65 MPa),并且前者的起始分解温度比后者提高了近10℃,说明前者的应用前景比后者更广阔。     

国内纳米二氧化钛制备的研究进展

纳米二氧化钛由于其许多优异的性质而显示出日益广阔的应用前景,纳米二氧化钛的制备因此成为研究的热点之一。主要对我国在纳米TiO2粉体、纳米TiO2薄膜、一维纳米TiO2及其阵列的制备研究工作进行了综述,指出了当前在制备研究方面存在的不足,展望了今后的主要研究方向。     

膜生物反应器的优化设计

膜生物反应器(MBR)在城市污水和工业废水的处理中受到了越来越多的重视。但目前限制其广泛应用的一个主要的障碍就是膜污染。在过去的几年中,关于膜污染的文章大量出现,它们详细阐述了膜污染的形成机理,并对减缓膜污染的措施进行了论述。本文是在总结以往研究的基础上,分析膜污染的形成原因并对膜生物反应器中减缓膜污染的方案提出优化设计。     

Properties of Phenolic-Based Ag-Filled Conductive Adhesive Affected by Different Coupling Agents

In this study, a phenolic-based Ag flake-filled electrically conductive adhesive (ECA) was investigated in terms of rheological, electrical, and mechanical properties. To clarify the effect of various Ag flake filler content and silane coupling agents on the characteristic of the ECA, rheological properties of the Ag flake-filled ECA paste, electrical resistivity, and shear strength of the cured ECA were investigated. Results showed that an increase of Ag flake content leads to an increase in both viscosity of the ECA paste and electrical conductivity of the as-cured ECA. Silane coupling agents-treated Ag flakes have a significant effect on the electrical resistivity and shear strength in the ECAs.     

环保增塑剂环氧腰果酚乙酸酯增塑PVC研究

首先,以腰果酚(cardanol)与乙酸酐为原料,对甲苯磺酸为催化剂,在无溶剂常温条件下合成了腰果酚乙酸酯(CA)。然后,以甲酸为催化剂双氧水为氧源合成环氧腰果酚乙酸酯(ECA)。考察了合成ECA的用量对聚氯乙烯(PVC)的热失重曲线、邵氏硬度、玻璃化转变温度、拉伸强度与断裂伸长率的影响。结果表明,随着增塑剂用量从20份增加到90份,PVC的热稳定性和断裂伸长率逐渐增加,拉伸强度、邵氏硬度以及玻璃化温度逐渐降低;与未加入增塑剂的PVC树脂及邻苯二甲酸二辛酯增塑的PVC树脂相比,所合成的ECA具有良好的增塑效果。     

Modification of ethyl 2-cyanoacrylate using silica and nitrile butadiene rubber to achieve high thixotropy and low internal stress

A mixture of fumed silica and nitrile butadiene rubber (NBR) is used to improve the viscosity and thixotropy of ethyl 2-cyanoacrylate (ECA) and to reduce the internal stress of ECA. Rheological characteristics of ECA/silica, ECA/NBR, and ECA/silica/NBR are measured using a rheometer and are presented using the viscosity and thixotropic index. The pristine and modified ECA were characterized using Fourier transform infrared spectrometer (FT-IR) and Thermal gravity analysis (TGA). The impact of additives on curing internal stress of ECA is measured and analyzed. Results shown that addition of fumed silica and NBR effectively improve the viscosity of ECA blends, which increases with an increased content of both additives. Thixotropic ECA/silica/NBR shows an apparent shear-thinning character and is well fitted by a power law equation. FT-IR spectra and TGA analysis indicated that the thixotropy of the obtained ECA/silica/NBR blends is mainly attributed to silica via the creation of hydrogen bonds between silica particles and between silica and polymers, and a synergistic effect between silica and NBR is shown to improve viscosity. The modified ECA showed considerable stability and their viscosity were slightly increased after 30 days. The presence of NBR is beneficial for silica dispersion in the ECA matrix and for a smooth surface of cured ECA. The added silica and NBR can alleviate the internal stress of the cured adhesive layer, and NBR plays a significant role in reducing internal stress. This work is devoted to developing thixotropic and low-shrinkage cyanoacrylate-based adhesives.     

Preparation and adhesive performance of electrical conductive epoxy-acrylate resin containing silver-plated graphene

The epoxy-acrylate (EA) was mixed with Ag-plated graphene (Ag-G), which was used as the conductive filler, to prepare the dual-curable electrical conductive adhesive (ECA). The characterization of Ag-G has been carried out by transmission electron microscope, X-ray diffraction, Raman spectrum, and X-ray photoelectron spectroscopy. Results showed that the Ag-G has been successfully prepared and the relative amount of Ag nanoparticles was 11.25?At%. The mechanical and conductive properties together with thermal stability of ECA have also been investigated. The shear strength reached to 4.67?MPa and the electrical conductivity of ECA reached to 0.41?S/cm when the content of conductive filler was 25?wt%, respectively. This content was regarded as the optimum. And, thermal analysis indicated that ECA exhibited better thermal stability than EA.     

SYNTHESIS AND CHARACTERIZATION OF A NEW ACRYLIC ADHESIVE MIXTURE FOR USE IN OCULAR STRABISMUS SURGERY

A new series of acrylic adhesive mixtures was specifically designed for use in strabismus surgery, more precisely to join the rectus muscles to the sclera. These two-part adhesives consisted of a mixture of ethyl cyanoacrylate (CN) and ethyl carboxyacrylate (ECA). ECA acted as a plasticizer imparting flexibility to the CN, and also as a nonreactive diluent, serving to reduce the exotherm in the reaction between CN and eye tissues. In this article, the synthesis of the ethyl carboxyacrylate is described, and the properties of different ethyl cyanoacrylate + ethyl carboxyacrylate mixtures were studied. The curing reaction of the adhesive mixtures was monitored using Fourier transform infrared (FTIR) spectroscopy and scanning differential calorimetry (DSC). The rheological properties of the cured CN-ECA adhesive films were studied using plate-plate rheometer experiments. To quantify the adhesion, single lap-shear tests produced between a rubber and the adhesive mixtures were performed and, to evaluate the adhesion to eye tissues, tensile strength measurements of superior rectus muscle/adhesive mixture/sclera joints were carried out. The 70CN-30ECA (v/v) adhesive mixture provided the most adequate balance between adhesion and mechanical properties in the joining of the superior rectus muscle to the sclera. The glass transition temperature of the CN-ECA adhesive mixtures linearly decreased with increase in the ECA content, and a lower degree of conversion during polymerization was obtained by increasing the ECA content. As a consequence, the CN-ECA mixtures were less stiff than CN, giving better performance in the joining of the rectus muscles to the sclera. Finally, the adhesion of CN was sufficiently decreased in CN-ECA mixtures, and the locus of failure was directed to the adhesive film in the joint between the rectus muscles and the sclera.     

Synthesis and characterization of a new acrylic adhesive mixture for use in ocular strabismus surgery

A new series of acrylic adhesive mixtures was specifically designed for use in strabismus surgery, more precisely to join the rectus muscles to the sclera. These two-part adhesives consisted of a mixture of ethyl cyanoacrylate (CN) and ethyl carboxyacrylate (ECA). ECA acted as a plasticizer imparting flexibility to the CN, and also as a nonreactive diluent, serving to reduce the exotherm in the reaction between CN and eye tissues. In this article, the synthesis of the ethyl carboxyacrylate is described, and the properties of different ethyl cyanoacrylate + ethyl carboxyacrylate mixtures were studied. The curing reaction of the adhesive mixtures was monitored using Fourier transform infrared (FTIR) spectroscopy and scanning differential calorimetry (DSC). The rheological properties of the cured CN-ECA adhesive films were studied using plate-plate rheometer experiments. To quantify the adhesion, single lap-shear tests produced between a rubber and the adhesive mixtures were performed and, to evaluate the adhesion to eye tissues, tensile strength measurements of superior rectus muscle/adhesive mixture/sclera joints were carried out. The 70CN-30ECA (v/v) adhesive mixture provided the most adequate balance between adhesion and mechanical properties in the joining of the superior rectus muscle to the sclera. The glass transition temperature of the CN-ECA adhesive mixtures linearly decreased with increase in the ECA content, and a lower degree of conversion during polymerization was obtained by increasing the ECA content. As a consequence, the CN-ECA mixtures were less stiff than CN, giving better performance in the joining of the rectus muscles to the sclera. Finally, the adhesion of CN was sufficiently decreased in CN-ECA mixtures, and the locus of failure was directed to the adhesive film in the joint between the rectus muscles and the sclera.