Preparation Of Copper Nanoparticles And Its Applicaton In RFID Antenna

Printed electronics is a newly environment friendly industry, differentprinting methods have different characteristics which can be applied indifferent fields. More and more countries and regions are concerned on thesimply, green, large area and flexible printed electronics process. Gravureprinting technology, which has faster speed, high plate printing resistance rate,will have a wide range of applications in the field of printed electronics industry.Conductive ink is an important crude material of the printed electronics,nano-silver conductive inks have been widely used, but the high price limits thesilver conductive ink’s wide application. Owing to the low prices, excellentelectrical conductivity, copper is considerate as a good substitute. This paperworks on the preparation of copper nanoparticles and its application in RFIDantenna, which researched on the reaction parameters and centrifuged andpurified the solution to prepare the gravure copper conductive ink and testedthe performance of the RFID antenna.Firstly, We prepared the copper disperse solution and studied the fivereaction parameters, such as reducing agents, protective agents, feed rate, pH,reaction temperature, was researched by the liquid phase reduction method.The copper particle size of60nm was attained in the mole ratio ofreductant/protective agent is3.75:1, protective agent/copper salt is1:1, thetemperature is70℃, pH value of11.0, intermittent feeding speed is6mL/min.According to the basic experiments and appropriately adjusted the reactionparameters,1280g copper nanoparticles were obtained in one pot and theaverage size was144nm. To further reduce the content of the protective agentand added the solvent with a low sintering point to prepare the free ofhigh-temperature heat treatment copper conductive ink, the sheet resistanceof93mΩ/□, resistivity of5×10-4Ω cm after sintered at50℃without inertatmosphere. After purification and concentration the reaction liquid, the aqueous basedand the organic solvent stable Cu inks were prepared, the solid content andthe viscosity respectively are35.15%,1.28Pa s and58.74%,6.29Pa s. Theconductivity of the free of high-temperature sinter Cu ink was only30%greaterand stable in10h after sintered at50℃.The58.74%of solid content solvent-based copper the conductive ink wasused to print the RFID antenna on the PET, PI substrate under the printingspeed of5m/s, the plates ink cell depth of15μm,10μm,5μm. The resultindicated that the RFID antenna pattern printed by the ink cell depth of15μmwas complete, clear lines, thick ink layer and with the ink cell depth reduce, theprinted lines turns blank cavity. The diffusion of the horizontal linesperpendicular to the printing direction is greater than the vertical lines parallelto printing direction, the line width smaller, the diffusion rate higher. The inklayer thick on the PI is higher than that on PET and the resistivity up to6.5×10^-5Ω cm after sintered at300℃.The roughness of the lines printed on the PIsubstrate less than the lines printed on PET substrate. PI is non-absorbingmedium, without any treatment, the ink adhesion on the PI substrate is poor,only4B.