交流安规瓷介电容器

研制、开发并生产高品质的交流安规瓷介电容器势在必行,并能满足国内需求,还可以出口创汇.     

交流安规瓷介电容器交流安规瓷介电容器

研制、开发并生产高品质的交流安规瓷介电容器势在必行，并能满足国内需求，还可以出口创汇。     

低温固化银浆的制备及树脂粘结相对其性能影响的研究进展

低温固化银浆广泛应用于电子标签、薄膜开关、触摸屏、印刷电路和太阳能电池等领域。本文对低温固化银浆的制备进行了系统总结,并重点叙述了太阳能电池片用低温固化银浆与柔性基材用低温固化银浆的制备。同时也总结了树脂粘结相对低温固化银浆性能的影响。低温固化银浆中的导电功能相要优先选用片状或片状球状相结合的微纳米银粉,树脂粘结相的选择在满足其使用要求的前提下要优先考虑其粘结性。为了开发出更好的低温固化银浆产品,除导电功能相和树脂粘结相外,还需深入探究溶剂及助剂等成分对低温固化银浆性能的影响。     

DJ—84型电容器击穿测试台

目前我国生产瓷介电容器的厂家其电容抗电强度的检验都是由击穿装置代替的,使用这种仪器来进行抗电试验主要存在下面两个方面的问题:1.按工艺文件要求所要测量的每个电容器只能是一个一个地插上去,经10s 或20s 加     

金属膜电极层对Na2O-PbO-Nb2O5-SiO2玻璃陶瓷电容器电性能的影响

玻璃陶瓷电容器内电极结构及界面形貌对电性能有重要影响.采用磁控溅射法在介质层与银浆料电极间分别制备了Pt、Au、Cu和Ag金属膜内电极层,研究此电极层对Na2O-PbO-Nb2O5-SiO2玻璃陶瓷电容器电性能的影响.与单层浆料的电极结构相比,引入Pt、Au金属膜可以更有效地改善电性能:等效电容值增加25%,漏电流降低一个数量级.由SEM结果可知:Pt、Au、Cu膜与玻璃陶瓷紧密的界面接触能够抑制银向介质中扩散;然而,采用单层银浆料或引入Ag金属膜的样品界面多孔且银扩散严重.以上分析表明:Pt、Au金属膜电极层能够改善玻璃陶瓷电容器界面微观结构,有效抑制银的扩散,提高整体电性能.     

银粉性质对太阳能电池浆料的影响

作为传统化石能源的有效替代品,太阳能电池引起了学者们的广泛关注。导电银浆作为太阳能电池的重要原料,影响着太阳能电池的光电转换率和度电成本。银粉作为银浆中的导电相,其性能对银浆的电性能、流动性、粘附性等性质起着关键作用。近年来针对银粉的形态、尺寸、分散度、粒度分布和振实密度对导电银浆电性能的影响有较多研究。研究表明银粉的形态和粒径是决定银浆导电性、烧结质量等特性的主要因素;银粉的振实密度也是影响烧结厚膜的致密性以及电池的光电转化率的重要因素。在银粉制备过程中,不同种类的分散剂会影响银粉的分散性,从而影响银浆的细度、粘附性和电阻率。     

Bi2O3掺杂堇青石陶瓷坯片与导电银浆共烧行为的研究

采用Bi2O3进行掺杂,成功地将堇青石陶瓷坯片的烧结温度降低到900℃。利用水基流延法制备堇青石坯片,研究了堇青石流延坯片的性能及其与导电银浆的共烧行为。结果表明,在900℃烧结的堇青石陶瓷坯片主晶相为α相,烧结试样具有良好的致密性和介电性能,且与导电银浆具有较好的共烧匹配性。     

水性聚氨酯/丙烯酸酯基多维度导电银浆的制备及低温固化特性

采用醇热法制备了纳米银颗粒、纳米银线和微米银片，对其进行多维度配合作为复合导电填料，以水性聚氨酯/丙烯酸脂复合树脂(WPUA)为载体和黏结相，采用搅拌混合法制备了水性树脂基多维度低温固化导电银浆。利用透射电镜、扫描电镜、水接触角测试和电阻测试，研究了不同固化温度对导电银浆成膜后的力学性能、导电性能及亲疏水特性的影响。结果表明，随着固化温度的上升，银浆漆膜的硬度、附着力及耐水性逐渐增加，WPUA基银浆漆膜的硬度在120℃时可达到3H等级，附着力在100℃可达到1等级，水接触角在140℃时可以达到93°；而WPUA银浆漆膜的电阻率随着固化温度的上升，呈现先增加后减小的趋势，在固化温度为160℃时的电阻率为0.19×10^-3Ω·cm。文中制备的多维度复合导电银浆在柔性电子印刷领域有着很好的应用前景。     

太阳能电池导电银浆的研究进展与市场现状

综述了国内外太阳能电池导电银浆的最新研究进展,介绍了银浆中各组分(银粉、玻璃粉、有机载体以及添加剂)对银浆性能的影响,分析了国内外太阳能电池导电银浆市场的应用与需求现状,并对我国导电银浆国产化提出了思路与对策.     

基于导电银浆流变特性的导线印刷品质分析与控制

提出了高精度电子产品印刷品质的评价指标,然后根据银微粒在银浆聚合物基体中的受力情况,分析了导电银浆的流动性和触变性对导线印刷品质的影响和墨膜中的银微粒体积分数与浆体流变特性之间的关系,进而提出了银浆中银微粒填充量及墨膜干燥状态是影响导线印刷品质的主要因素.通过大量实验样本的分析和评价,提出了确定银浆中银微粒渗流阈值及墨膜最佳干燥条件的目的和方法,为有效控制导线印刷品质提供了理论支持和实践指导.     

Surfactant-stabilized copper paticles for low-temperature sintering: Paste preparation using a milling with small zirconia beads: Effect of pre-treatment with the disperse medium

Copper paste is considered as a promising candidate for printed electronics in replacement for silver paste. This is owing to copper which has anti-electromigration property, lower cost, and similar conductivity and compared with silver. We synthesize a copper nanoparticle (NP) paste that can be sintered at low temperature for high conductivity. The copper NP paste composes of 50 wt% copper NPs and dipropylene glycol (DPG) as the disperse medium. The effect of DPG coating and various conditions of milling with small beads on improving the dispersity of copper NPs has been investigated. The optimum conditions for milling are at 1000 and 2000 rpm for 30 min. This results in a volume resistivity of 6.62 × 10^-6 Ω·cm after sintering the copper NP paste at 200 °C.     

Effects of organic additives on the microstructural,rheological and electrical properties of silver paste for LTCC applications

Silver powders were prepared by a chemical reduction method. Effects of different surfactants during this preparation process were examined. Using these silver powders, silver pastes were prepared for low temperature co-fired ceramics (LTCC) applications. Another batch of different surfactants were added into the silver paste and evaluated. Moreover, various organic thixotropic agents were used to modify the thixotropy behavior of the silver paste. It was found that the surfactants of PVP (Polyvinyl pyrrolidone, for preparation of the silver powder) and Span-85 (for the preparation of silver paste) exhibited the best performance, with an electrical resistivity of 0.11 mΩ mm. The silver paste with the thixotropic agent of hydrogenated castor oil shows the largest thixotropic index of 1.56. Using different organic additives, the microstructural, rheological and electrical properties of the silver paste can be considerably improved, and our results shed light on the optimization of the silver paste for LTCC applications.

     

Analysis of the formation mechanism of coarse-dense structure of silver paste in die bonding

The flow behavior of silver paste during die bonding was analyzed by numerical simulation to clarify the formation mechanism of coarse-dense inhomogeneous distribution of silver particles in a die-attach layer. Depending on the loading speed of a die, silver particles in the paste flow and form a coarse-dense distribution under a die. The microstructure of the paste before sintering was observed by X-ray computer tomography (X-ray CT) and Scanning Electron Microscope (SEM). At a slow loading speed of 1.0 μm/s, the paste is densely packed with silver particles along the diagonal of the die. A coarse structure was observed in the other area of the paste. On the other hand, at a high loading speed of 60.0 μm/s, there was no clear segregation and the paste layer has an almost uniform structure. The SPH method was used to calculate the flow behavior of particles in the paste, and the flow velocity and shear stress of the paste were calculated. The paste velocity and shear stress in the region along the diagonal of the die is smaller than those in other area of the die. A comparison of the shear stress applied to the paste at different loading speeds showed that the smaller the loading speed, the larger the value of summation of shear stress. The difference between the maximum and minimum shear stress in a lateral direction through the center of the die increases with decreasing of loading speed. Thus, a large difference in local shear stress acting on the paste causes the formation of coarse-dense structure of the silver paste. It was found that it is necessary to eliminate local differences in the shear stress acting on the paste in order to achieve uniform joint the silver paste to the substrate without forming a coarse-dense structure.     

基于分子动力学的丝网印刷柔性传感器电极导电性机理研究

目的 研究提高丝网印刷柔性传感器电极的导电性,为提升柔性传感器的电学性能提供参考依据。方法 首先采用分子动力学（Molecular Dynamic,MD）模拟方法,建立在Wenzel模型下导电银浆团簇在不同粗糙因子下的对苯二甲酸乙二醇酯（Polyethylene Terephthalate,PET）表面铺展的分子动力学模型,其次分别计算各体系下的结合能,用以表征不同体系下PET表面对导电银浆团簇结合能力,接下来通过丝网印刷实验的方法探究银浆与不同粗糙因子PET的结合能力对传感器电极的导电性的影响。结果 仿真结果表明,导电银浆团簇在不同粗糙因子的PET表面的铺展过程中会陷入粗糙表面的凹陷处,且导电银浆与基材的结合能随着PET粗糙因子的增加而增加。实验结果表明,使用不同粗糙因子的PET作为承印物能显著提升电极的导电性。相比于未处理的PET,随着粗糙因子的增加,导电线条的电导率逐渐升高,电阻率逐渐降低,方块电阻逐渐降低。电导率最大提升了77%,电阻率最大下降了43%,方块电阻最大下降了38%。结论 导电银浆在粗糙表面铺展的过程中会渗入基材的凹陷处,增加了吸附点位,使得银浆与基材的结合更加紧密...     

Te-Bi玻璃对晶体硅太阳能电池正银电极性能的影响

正银浆料是晶体硅太阳能电池金属化的关键材料, 环保型浆料是正银电极的主要发展方向之一。通过正交实验方法, 研究了不同配方和组分的Te-Bi玻璃对正银电极性能的影响。用TGA-DSC分析了Te-Bi玻璃和正银浆料的热处理特性, 用SEM分析了Ag-Si界面处银微晶的分布和大小, 利用隧道电流模型分析了玻璃对正银电极性能的影响规律。结果表明: TeO₂含量45wt%, Bi₂O₃含量36wt%的Z7玻璃, 其T_g为379.07℃, 对应的正银浆料在612.8℃出现吸热反应, 同时发生失重(-0.16%), 制作的多晶硅电池效率达到16.87%, 电极的附着力达到4.35 N。     

Impact of interface microstructure on adhesion force between silver paste and silicon solar cells’ emitter

The adhesion strength between silver paste and silicon solar cell’s emitter is a primary source of long-term degradation in solar modules. In this study, the interface microstructure between screen-printed silver thick-film and silicon solar cells’ emitter was studied. Three kinds of commercial silver pastes were printed on silicon solar cells’ emitter to form different Ag–Si contact structures. The interface microstructure between silver paste and emitter was observed by SEM, while the compositions of Ag thick-film were analyzed by EDX. The deductions we got from SEM and EDX were verified by the pull test for the first time. The results presented in this study give some suggestions to the development of silver paste and crystalline silicon solar cells’ fire-through.     

Investigation of contact resistance between silicon and silver paste made by screen-printing

In this paper, the front contact resistance of screen-printing crystalline silicon solar cells was investigated. By establishing a fine model for silicon and silver paste contact made by screen-printing and fire-through, the three kinds of conduction mechanism were analyzed quantitatively. According to the model, the comprehensive calculation of the contact resistance between silicon and silver paste sintering was made for the first time. The results calculated in this study suggest that the contact resistance of silicon and silver paste is about 1.20 mΩ for 125 mm × 125 mm single crystalline silicon solar cells, this approximately agrees with the measured values. By optimizing composition of silver paste according to our results, the silver consumption per watt can be reduced, and the efficiency of crystalline silicon solar cells can be further improved. The results laid the foundation for studying the screen-printed crystalline silicon solar cell front contact metallization system.     

Electrical properties of silver paste prepared from nanoparticles and lead-free frit

Recently, PbO containing glass systems in commercial silver paste have been used due to their low glass transition temperature, good thermal and electrical properties. However, PbO is a hazardous material to both health and the environment. In this study, Pb-free silver paste was prepared by mixing commercial silver powder and silver nanoparticles. The commercial powder has an average particle size of 1.6 microm. The silver nanoparticles with particles size of 20-50 nm were synthesized by a chemical reduction method using surfactant. Pb-free frit was added into the mixed silver powder as the amounts of 3, 6 and 9 wt%. Using the obtained paste, thick films were fabricated by a screen printing on alumina substrate and the films were fired at temperature from 400 to 550 degrees C. The films had thickness of 6-11 microm and sheet resistivity of about 4-11 microomega cm.     

光伏电池用背电极银浆的制备与性能研究

通过化学还原法制备了粒径均一的高分散超细球形银粉,粒径1～2μm,并研究了影响银粉制备的因素。以此银粉为基础,选择合适的组分,制备晶硅光伏电池用背电极银浆,并改善了配制工艺,节省了制备步骤。经过印刷、烧结后,测试了银浆的焊接拉力、电阻率及与铝浆的复合性,达到了工业生产应用的要求。