Study On The Sintering Process And Mechanism Of Silveracetate-Based Particle-Free Ink

In recent years,the development of micro-nano processing technology and flexible wearable technology has put forward new requirements for the printed electronics industry.As the most widely used functional material in printed electronic materials,conductive ink has arisen great interest in the printed electronics industry.At present,as a kind of conductive ink,silver-based ink with excellent conductivity and thermal conductivity has been studied to develop for the application in electronic devices such as radiofrequency electronic tags,wearable devices,solar cells,displays,and flexible sensors.However,traditional silver nanoparticle inks are prone to clog the nozzle during printing,and the post-processing temperature required for the printed circuit is high,which limits the types of polymer substrates.Reducing the post-processing temperature of the conductive ink to make it compatible with various polymer substrates is the focus of current research,which will also greatly promote the development of flexible electronic devices.Since the particle-free activate silver ink is not limited by particle size,and does not contain organic matter,high conductivity silver patterns can be obtained at a low temperature.In this paper,particle-free active silver ink was synthesized with silver acetate,formic acid,and ammonia.And inkjet printing technology was used to fabricate patterned silver on the modified polyimide substrate.Thermal sintering and plasma sintering were used to reduce the silver ions in the particle-free activate silver ink and join the reduced silver nanoparticles.The resistivity of the silver wire sintered by thermal is 1.2×10^-7?·m,which is 7.5 times that of bulk silver.The resistivity of the silver wire sintered by plasma is 8×10^-8?·m,which is the resistivity of bulk silver 4.8times.In this paper,the influences of thermal sintering parameters,plasma sintering parameters and printing parameters on the electrical properties of silver wires and the mechanism of thermal sintering and plasma sintering were studied.The sintering mechanism of silver nanoparticles is proposed:The sintering mechanism of silver nanoparticles is proposed:the thermal sintered and plasma sintered silver first decomposes under the action of heat transfer and plasma active substances,respectively,then the silver nanoparticles were reduced and sintered.By analyzing the chemical composition of the silver wire,it can be determined that the effect of plasma sintering is better than that of thermal sintering.Under the combined action of thermal sintering and plasma sintering,the resistivity of the silver wire can reach 6×10^-8?·m,which is only 3.6 times that of bulk silver.