一种新型电子标签天线用导电油墨的配制

基于电子标签天线对导电性要求较高的特性,实验以自制Ag作为导电填料。论文采用液相化学还原法,以次磷酸钠为还原剂,还原硝酸银制备纳米银胶。通过控制反应条件(温度、pH值等)、反应物的量(六偏磷酸钠、PVP),制备出粒径分布均匀、分散稳定性优良的纳米银胶。通过向银胶中添加电解质,析出纳米银粉,加上适量的助剂、溶剂和分散剂,制备了水性丙烯酸树脂和水性聚氨酯基导电油墨。分析了影响油墨导电性能的各影响因素。     

铜粉添加量对铜酚醛树脂导电油墨性能的影响

以微米级铜粉为导电填料、酚醛树脂为粘接剂制备了导电油墨,并将该油墨以聚酰亚胺薄膜为基底,采用丝网印刷技术制备导电涂层。研究了铜粉添加量对铜酚醛树脂导电油墨的黏度、固含量以及导电涂层的微观形貌、电阻率和附着力的影响。研究表明,当铜粉添加量质量分数为70%时,制备的铜酚醛树脂导电油墨具有良好的性能,该导电油墨经丝网印刷得到的导电铜膜经低温固化后具有良好的电性能,其电阻率最低可以达到53.865×10–3Ω·cm。     

低温固化银系导电油墨导电性能的影响因素

为了提高低温固化银系导电油墨的导电性,对导电机理进行了研究。通过实验研究了聚合物分子结构,银粉的含量、形貌、粒径,溶剂种类对导电性能的影响。得出:氯化聚乙酸乙烯为主体树脂,以片状与球状混合银粉(质量比为9:1)为导电填料,并以酮和酯组成混合溶剂,调制的导电油墨导电性最好,其Rs达9 mΩ/□。     

柔性银包铜基导电线路的制备与性能

针对导电银浆价格高、导电铜浆易氧化等问题,采用银包铜粉作为导电填料,聚氨酯改性丙烯酸树脂为树脂基体,通过丝网印刷在聚酰亚胺薄膜上印制导电线路,并用热固化的方式进行固化,从而获得导电性能优良的柔性银包铜基导电线路。结果表明:当银包铜粉的含量为65%(质量分数)时,制备的导电胶各项性能达到最佳值,满足丝印要求,平均膜厚为29.25μm,固化后得到的导电膜电阻率达到最低值1.06×10~(-3)Ω·cm。     

纳米碳球屏蔽涂料的制备与导电性能研究

利用复合法制备了以纳米碳球、非晶合金粉体作为填料、丙烯酸树脂为基的电磁屏蔽涂料。通过表面电阻率和屏蔽效能测量后发现,由于使用的纳米碳球本身导电性较差,且沉降较严重,涂层并没有表现出很好的屏蔽效果,当碳球含量达到90%时,屏蔽效能最高达到5dB左右,平均在3dB,但已经达到了体系的渗滤阈值,证明距涂层实际应用还有一定的距离。     

纳米银链增强导电复合材料的导电性及柔性的机理

本论文针对柔性导电复合材料的导电性差和柔性差这两个亟需同时解决的关键问题,分别从导电填料的柔性化及降低填料含量两方面着手,首先以DNA大分子链作为模板,制备了大小均一、链状排列的柔性纳米银链及纳米银链/聚氨酯柔性导电复合材料。采用紫外-可见吸收光谱（UV-vis）、透射电镜（TEM）对纳米银链进行了表征. 研究发现,当保持填料总含量一定,纳米银链的含量为4 wt%时,复合材料的电阻率及形变下的电阻变化率达到最佳值,分别为2.13×10-4 Ω cm和3.6. 利用扫描电镜对（SEM）对纳米银链导电复合材料的界面结构进行了表征,探讨了纳米银链增强导电复合材料导电性及柔性的机理;以纳米银链为单一填料时,导电复合材料具有优异的柔性. 分别采用机械共混法及泡沫模板法制备了两种不同的纳米银链导电复合材料,对其导电性能进行了研究. 结果发现,泡沫法制得复合材料可以在低填料含量下达到更高的导电性,当纳米银链含量为60 wt%时,方阻为56 Ω/sq,低于共混法制得填料含量为65wt%时的导电复合材料（98 Ω/sq）.     

石墨和石墨烯填充导电硅橡胶的拉敏特性研究

以107室温硫化硅橡胶作为橡胶基体,石墨和石墨烯纳米薄片为导电填料,用常温加压固化的方法制备出导电硅橡胶。研究了石墨含量及拉力对导电硅橡胶电阻的影响以及填充石墨烯对导电硅橡胶导电性能的影响。结果表明:仅添加石墨,且石墨质量分数为41.2%时,拉敏性能最佳;在导电填料总含量为质量分数35.5%~41.2%时,添加0.04 g石墨烯能有效改善其导电性能,但拉力敏感性降低。     

水性镍系电磁屏蔽涂料的制备及导电性能研究

以水性丙烯酸树脂为基料,导电镍粉为填料以及水和助剂,制备成水性电磁屏蔽导电涂料。讨论了分散时间、黏度、成膜助剂、基材对导电性能的影响,并通过涂层的微观结构和导电机理,探讨了造成这些现象的原因。所制成的涂料在频率100kHz~1.5GHz范围内,屏蔽效能为45~60dB。     

铜酚醛树脂导电油墨的研究

高性能导电油墨的开发是印制电子技术研究焦点之一。本文利用自制热固性酚醛树脂做联接剂,铜粉做导电填料来制备导电油墨。通过试验获得的最佳配方中各组分比例为:合成树脂组分中苯酚:甲醛溶液:氢氧化钠=1:(4-5):3,铜粉重量占固化后油墨总重的75%-80%。在此配比范围内,150℃加热固化后导电油墨的电阻率可以达到实际应用要求的100Ω/cm。     

用喷墨打印法直接形成铜导电线路图形

金属纳米粒子的喷墨打印直接形成金属导电线路,低成本、低消耗、工艺过程简单,是一个很具吸引力的方法。虽然目前大多数的研究集中在新金属方面,如金和银,但是本实验开发出一种廉价的导电材料作为替代品,即铜纳米粒子导电油墨。用多元醇过程制备出粒径为40nm～50nm的铜纳米粒子,把铜离子很好的分散在低粘度的导电油墨中。实验成功地演示了用铜导电油墨直接形成导电线路的方法。喷墨印刷形成的铜导电线路图形具有金属般的外观,并且在热处理后具有很好的导电性。薄膜在真空中以325℃的温度持续1h后,薄膜的电阻率达到17．2μΩm·cm。     

导（散）热印制板

概括地评论了散（导）热PCB 的发展的原因和环境,PCB的高密度化和信号传输的高频化是散（导）热PCB发展的两大主要原因,散（导）热PCB主要是通过三种方法（金属芯板、金属基板和导热性CCL）来实现。     

High performance conductive adhesives

Isotropic conductive adhesives (ICAs) have been developed as an alternative for traditional tin/lead (Sn/Pb) solders for electronic applications. Compared to mature soldering technology, conductive adhesive technology is still in its infant stage, therefore, there are some limitations for current commercial ICAs. Two critical limitations are poor impact performance and unstable contact resistance with nonnoble metal finished components. These limitations seriously hindered the wide applications of ICA's. No current commercial ICAs show both desirable impact performance and stable contact resistance. In this paper, novel conductive adhesives were formulated using mixtures of an epoxide-modified polyurethane resin and a bisphenol-F type epoxy resin and a corrosion inhibitor. Cure profiles, rheology, and dynamic mechanical properties of the conductive adhesives were studied using a differential scanning calorimeter (DSC), a rheometer, and a dynamic mechanical analyzer (DMA), respectively. Impact strength and contact resistance with several nonnoble metals (Sn/Pb, Sn, and copper) of these conductive adhesives were tested and compared to those of a commercial conductive adhesive. It was found that these in-house conductive adhesives showed superior impact performance and substantially stable contact resistance with nonnoble metal finished components during elevated temperature and humidity aging     

Combined resistive and conductive sheets

To simulate a thin layer of material whose permittivity and permeability both differ from the values for the surrounding medium, a combination resistive and conductive sheet is defined and its properties described.     

Endurance behavior of conductive yarns

Various companies are industrializing ‘photonic’ textiles for medical and architectural applications. Here we report reliability testing of photonic textiles based on woven textiles with integrated copper-based conductive yarns used to drive attached LEDs. These textiles were subjected to cyclic mechanical stress tests and the cycle life was analyzed in terms of fatigue. Results show that failure is due to wire fractures at the transition from the rigid component to the compliant textile. The results are in good agreement with Cu-fatigue data from literature. This shows that it is possible to estimate the lifetime of electronic textiles under use conditions by the mechanical fatigue of the conducting yarn material properties.     

Shielding effectiveness of conductive polymers

The plane wave shielding effectiveness of two new materials, conductive polymers polyacetylene and PBT doped by ion implantation with iodine, is evaluated as a function of frequency, electrical thickness, doping, polarization, and angle of incidence. Conductivity of the polymers, measured in previous investigations by the cavity perturbation technique, is used to compute the overall reflection and transmission coefficients of single and multiple layers of the polymers. The polymers are found to display excellent shielding effectiveness (better than 40 dB over a substantial frequency band). With recent advances in synthesizing stable highly conductive polymers these light-weight mechanically strong materials appear to be viable alternatives to metals for EMI shielding     

无颗粒银导电墨水及高导电率银薄膜的制备及其性能研究

以酒石酸银为原料、1,2丙二胺为络合剂、无水乙醇为溶剂制备了无颗粒银基导电墨水,将该墨水棒涂于玻璃、PET、PI和相纸基板,在加热板上130℃固化5 min获得银膜,通过XRD、FTIR、TG-DSC、FE-SEM和四探针测电阻率方法对合成的酒石酸银粉体、导电墨水和银膜进行表征。结果表明:导电墨水的分解温度远低于银前驱体的分解温度;在不同基板上的银薄膜表现出不同的形貌和颗粒尺寸,其中相纸基板上的电阻率最低为6.7×10~(–6)?·cm。喷墨打印银线条于PI基板,130℃固化5 min后,银线条宽度约100μm,表面平整光滑且微观组织致密,在柔性印刷方向有良好的应用前景。     

应用于导电墨水的铜胶体的研究

将自制的纳米铜粉作为导电墨水的导电填料,通过添加一定量的分散剂、表面活性剂等其他助剂,超声波粉碎后制得纳米铜导电墨水。结果表明:随着固含量的增加,超声波分散时间越长,墨水的黏度越大。但电导率与超声波分散时间并无直接关系。随着固含量和烧结温度的增加,导电薄膜变得更致密、平整,电阻率逐渐降低。经过300℃烧结后电阻率可减至9.4×10–3Ω·cm。     

Laser ablation of anisotropic conductive adhesive

A laser ablation process has been developed and optimized for the rework of anisotropic conducting adhesive bonds. Ablative photodecomposition of the adhesive matrix and simultaneous removal of the conductive particles is a dry, controllable, and readily implemented alternative for removal of these materials and preparation of the substrate for reprocessing. The ultraviolet absorption spectrum was evaluated, and ablation results evaluated at both λ=193 nm and λ=248 nm. The λ=193 nm wavelength was determined to be optimal for complete adhesive removal and minimal thermal damage to the substrate. A systematic evaluation of the fluence level, angle of incidence, and cumulative exposure established the parameter range between complete adhesive removal and substrate damage. The surface topology of reworked samples showed little change from the original, but a resistance increase was observed for the rebonded circuits. This process appears superior to competing methods because it is both dry and restores the bonding surface to nearly original condition     

导电聚合物直接电镀技术

虽然传统的PTH（镀通孔）工艺十分成熟,应用广泛,但仍有很多不足之处。因此一些取代传统PTH工艺的直接电镀技术应用而生。导电聚合物直接电镀技术已经较为成熟,文中系统介绍了EcopactCP工艺的导电聚合物直接电镀技术。     

导电胶粘剂的研究进展

随着微电子技术的发展以及环保意识的增强,作为Pb/Sn焊料替代物的导电胶粘剂,已成为当前研究的热点和重点。介绍了导电胶粘剂的导电机理及其组成、功能和分类。重点概述了近年来国内外导电胶粘剂的研究现状,并展望了未来导电胶粘剂的研究方向。