Synthesis Of Silver Nanoparticles For Printed Electronic And Chemical Sintering At Room Temperature

As a modern technology in the manufacturing process of flexible electronic products,printed electronics technology has received a wide attention due to its high efficiency,low resource consumption,low environmental pollution and short production cycle.In the fabrication process of printed circuits and devices by using nano-silver materials,sintering processes is required in order to trigger coalescence and fusion of nanoparticles to form conductive structure.However,there is an unavoidable heating temperature rise process above 200 °C in the traditional post-processing sintering method of printed electronics.Excessive temperatures rise can result in failure of printed electronics and devices,limiting the application of printed electronics.Therefore,a new post-processing sintering process to cause the fusion process of-silver nanoparticles at room temperature is urgently needed.In this paper,silver nanoparticles are facilely synthesized by ethylene glycol(EG)while polyvinyl pyrrolidone(PVP)serves as the stabilizer under heating conditions.The growth mechanism,grain orientation,surface morphology and coating conditions of the silver nanoparticles are analyzed.The size and size distribution of silver nanoparticles by chemical reduction are studied by the reaction temperature,silver nitrate concentration,mass ratio of silver nitrate and PVP.Based on the prepared silver nanoparticles,chlorine ions are used to trigger desorption of PVP on the silver nanoparticles surface and achieve the fusion of nanoparticles at room temperature.As new post-processing sintering process,the chemical sintering principle and sintering morphology at room temperature were analyzed.The influence of sintering time and chloride ion concentration on the resistivity after sintering was studied to find the best room temperature chemical sintering process.Micro-pen direct writing devices are used to print wires on different flexible substrates by using the synthesized silver nanoparticles.The printing performance of flexible substrates such as FR-4 sheet,PI substrate,and paper substrate are analyzed and the line width and morphology of the printed circuit are characterized.The chemical sintering at room temperature is used to sinter the directly printed conductors on different substrates and the lines are connected to a simple circuit after being chemical sintering to light up an LED.