Preparation And Application Of Particle-free Conductive Ink Of Inkjet Based On RFID Antenna

In recent years,Printed Electronics,as an emerging technology,developing very fast,it's an important innovation of microelectronics.It is widely used in sensors,paper battery,membrane switches,solar cells,RFID smart labels and other fields.The key point of Printed Electronics is transferring functional conductive ink onto the substrate by printing,making it has a corresponding electrical properties and achieving the production of electronic components.The conductive ink contains functional materials,therefore,the conductive features can be implemented.Among them,particle-free conductive ink has low sintering temperature,no solid particles,high stability,enabling the general substrate transfer.In this study,selecting silver citrate as conductive metal precursor,which has high stability,low decomposition temperature and high silver content.It can be achieved through a simple reaction of the ion-exchange,the preparation process is relatively simple and has higher yields at room temperature.In order to verify whether the product is silver citrate or not,the product was characterized by infrared Organic amine is the complexing agent to dissolve silver citrate,in this study,we examined the status of silver citrate dissolved in various organic amines,and the conductivity of ink and surface condition of conductive thin film were characterized.Adding alcohol substance to adjust the viscosity and surface tension of the ink.The experiment tested the effects of adding different alcohols about the conductivity of ink and surface condition of conductive thin film,and combine with their own viscosity and surface tension values,we ensured two kinds of alcohol meet our requirements.When sintering,the difference of temperature between the edge and center of the drop,caused "coffee ring" on the conductive thin film.With the aid of Marangoni convection,choosing an alcohol with high boiling point and high surface tension,Successfully achieved weaken or eliminate the effect.Based on the results of the above experiments,taking silver citrate as conductive metal precursor,sec-Butylamine as complexing agent and ethanol,tert-butanol and ethylene glycol as media adjusting the viscosity and surface tension,prepared a kind of particle-free conductive ink with high conductivity and low sintering temperature.And the viscosity,surface tension,conductivity of the ink and surface condition of conductive thin film were characterized.Under 20? the viscosity of the ink is 5.83cp,surface condition is 25.8dyn/cm.PET as the substrate and coating,after sintering 20 min under the conditions of 150?,the square resistance of conductive thin film is only 1.49?/?.This paper also used the conductive ink,printed an UHF RFID Antenna by inkjet printer,the antenna has excellent conductivity and adhesion.