Study On The Factors Affecting The Transfer Rate Of Conductive Ink Based On Screen Printing

The sunrise industry printing industry,printing electronic technology,with its large area,flexibility,personalization,low cost,green environmental protection and other advantages,has become an important means of preparing electronic products.Printed electronics technology is a comprehensive technology that combines printing technology with electronic technology.With its rapid development,conductive inks and related technology applications have also received great attention.In the process of industrialization of printed electronics,in order to obtain a printed circuit with excellent electrical conductivity,it is necessary to ensure a high transfer rate of conductive ink during printing.Among all the printing methods,screen printing is the earliest printing method for printed electronic products.Its viscosity is large,and it is often used to print conductors,resistors,and joint materials,which are relatively easy to achieve high-viscosity functional materials.The screen printing process equipment is simple and easy to handle.It can apply high solid content materials,ensure high transfer rate of conductive ink,and obtain thicker ink layer to realize highly conductive printed circuit.Aiming at the screen printing,this paper has studied a series of factors that affecting the transfer rate of conductive ink in the printing process,including the performance of screen printing conductive ink and its printing suitability on ink transfer rate;different printing process parameters,the influence of plate mesh number,printing pressure,printing speed and embossing angle on the transfer rate of conductive ink;the influence of the surface characteristics of the printing material on the transfer rate of conductive ink;the influence of different post-treatment temperatures on the conductivity of the ink layer.The results show that the PET film with a surface energy of 58 mN/m and a contact angle of 25.5°,a printing pressure of 105 N,a printing speed of 7 m/min,a plate mesh of 300 mesh,and an embossing angle of 50°.The conductive ink transfer rate is optimal,and the conductive coating has the best conductivity.In this paper,DBE(dibasic ester mixture,DuPont called DBE)environmentally friendly solvent is used as a diluent.By changing the solid content of conductive filler silver particles in conductive ink and using mechanical stirring method to prepare conductive inks with different viscosities,the effect of the viscosity of the ink on the ink transfer rate was studied,and thus the conductivity of the coating.The results show that when the dilution ratio of conductive ink to DBE is 20:2 and the viscosity of conductive ink is 1530mPa·s,the transfer rate of conductive ink is optimal.In this paper,the effect of post-treatment temperature on the conductivity of the coating was studied.By setting a series of drying temperatures,the printed samples were characterized by a four-probe tester.The results show that the conductive coatings with long drying time at the same temperature Good electrical conductivity;when the temperature is lower than 60°C and the drying time is less than 20 minutes,the conductive performance of the conductive ink is about 60%~70% under the same drying time and temperature,because the ink layer is thick that more than 10 ?m,the solvent volatilizes slowly,resulting in poor conductivity.Drying at 120 ° C for 10~20 minutes is selected,and the relatively thin drying time of the ink layer is greater than 10 minutes.The relatively thick drying time of the ink layer is less than 20 minutes.Finally,a printed silver coating was used as a metal cathode,and an ITO film was used as a transparent electrode to fabricate an electroluminescent device.The results showed that the electroluminescent device prepared by the printed coating that transfer rate between 60% and 70%,and a thick printed layer between 6?m and 10?m had a high luminance,but the thickness is more than 10?m,the brightness is reduced.