【作者】 秦峻；

【导师】 堵永国；

【作者基本信息】 国防科学技术大学 ， 材料科学与工程， 2011， 硕士

【摘要】 随着物联网和RFID技术的快速发展, RFID电子标签的需求量越来越大,其应用形式也越来越广泛。RFID标签天线作为电子标签的关键组件,大多采用传统的蚀刻工艺制造,然而其在制造过程中会造成大量金属废弃物污染环境。RFID导电油墨制备电子标签的方法具有成本低、效率高、无污染等特点,是RFID标签天线制造技术的发展方向。本文以丝网印刷用RFID导电油墨为研究对象,从RFID导电油墨中导电相银粉的制备和应用、导电油墨粘结剂体系的设计和性能以及导电油墨流变学研究三个方面对RFID导电油墨进行了系统的研究。采用机械球磨法制备了不同片径的片状银粉,研究了原料球形银粉粒径对球磨工艺和片状银粉性能的影响。结果表明,银粉片径先随着球磨时间的增大而增大,片状化程度达到极限时,片径反而减小,而原料球形银粉粒径越小,达到完全片状化的时间越短;在球磨工艺相同时,原料球形银粉粒径越小,球磨后的片状银粉越不规则。采用不锈钢辅助醇热法高浓度、大规模制得低长径比的适合丝网印刷工艺的一维银线;研究了不同种类的银粉对导电油墨导电性能、粘度以及溶剂释放性能的影响规律。设计了一种热固性-热塑性高分子共混粘结剂体系,其中热固性树脂为环氧树脂,热塑性树脂为PVB(聚乙烯醇缩丁醛);通过对环氧树脂粘结剂体系固化行为的研究和溶剂体系的选择,初步确定了导电油墨的固化工艺为鼓风干燥箱内120℃固化至少30min;研究了导电油墨中银粉含量、粘结剂树脂组分对固化膜体积电阻率、附着力、抗弯折性能和印刷特性的影响。结果表明,导电油墨中银粉含量越高,固化膜导电性能越好,但脆性越大;粘结剂体系中PVB含量越高,导电油墨固化膜抗弯折性能越好,附着力更强;高PVB含量的导电油墨在高剪切速率下的粘度较大,粘弹性中粘性组分也较大,使得印刷后的图案边缘不齐,出现毛刺现象。采用流变仪对导电油墨剪切稀化特性、动态屈服应力、触变性大小、触变结构的恢复速度和动态粘弹特性进行了测量。研究了导电油墨中银粉含量、银粉种类以及触变剂含量对导电油墨流变性能和抗沉降性能的影响情况;采用Cross和Herschel-Bulkley流变模型对测出的导电油墨粘度曲线进行拟合,得到了导电油墨的屈服应力、零剪切粘度、无穷大剪切粘度等流变参数,与流变仪实际测试结果基本符合,对导电油墨配方性能的预测和设计工作具有重要的指导作用。更多还原

【Abstract】 With the rapid development of Internet of Things and RFID technology, the demand for RFID electronic label is growing and its application form extends with each passing day. As a key component of the electronic label, most of RFID electronic label antenna is prepared through traditional etching process. However, a large number of metal waste is produced in etching processing and may pollute the environment. Conductive ink printing method in RFID electronic tag preparation has the advantages of low cost, high efficiency, no pollution etc, which is the future development direction of RFID tag antenna manufacturing technology. The paper has chose screen printable RFID conductive ink as the object of study. A systematic study of RFID conductive ink was developed from three aspects: conductive phase silver powder preparation and application in conductive ink, the design of binder system in conductive ink and its performance, research on rheology of conductive ink.Different sheet sizes of flake silver powder were prepared by mechanically ball milling process. The effect of silver particle size on ball milling process and the properties of flake silver powder was studied. Silver flake diameter was increasing with milling time firstly. However, when the flaking process reached the limit, sheet size of flake silver powder decreased. The smaller sizes of silver particles, the shorter time sheet size reaching the limit and the more irregular flake silver powder with the same balling process. A steel-assisted polyol method has been proposed for high-concentration and large-scale preparation of screen printable 1D silver wires with low aspect ratios(10~20). Conductive properties, viscosity and solvent release property of conductive ink with different types of silver powder were investigated.A thermoset-thermoplastic resin blend was designed. Epoxy resin was used as the thermosetting resin and PVB(Polyvinyl butyral) was used as the thermoplastic resin. The curing process was 120℃in blast drying box for 30min according to the curing behavior of epoxy binder system and chosed solvents. The effect of silver content, binder resin components in conductive ink on volume resistivity, adhesion, printing and anti-bending performance of cured films were investigated. The higher silver content of conductive ink, the better conductive property and the bigger brittleness of cured film; The higher PVB content of Binder system, the better bending resistant performance and stronger adhesive force of cued membrane. In addition, conductive ink with higher PVP content had higher viscosity and more viscous components, so the pattern printed had the irregular edges and appeared many burrs.Shear-thinning characteristics, dynamic yield stress, thixotropy, thixotropic structure recovery rate and dynamic viscoelastic properties were measured using a rheometer. Rheological properties and anti-settling performance of conductive ink with different silver content, different silver types and thixotropic agent content were studied. Yield stress, zero shear viscosity and infinite shear viscosity of conductive ink obtained by curve fitting of viscosity measurable using Cross and Herschel-Bulkley rheological model were proved right and would play great important roles in conductive formulation design.更多还原