Micro-writing Process Of The Flexible Nano Silver And Conductivity Regulation

Traditional micro-nano manufacturing technology based on screen printing and lithography technology can not meet the requirements of flexible,miniaturized,low-cost,short manufacturing cycle of wearable electronic devices due to its own limitations.A new type of micro-nano manufacturing Method—Micro-write straight-through technology came into being.The unique working principle of the micro-writing technology perfectly fits the characteristics of the wearable electronic device,but the matching conductive ink must be a nano-scale conductive ink.In this paper,silver nitrate was used as precursor,glucose was used as reducing agent,and polyvinylpyrrolidone(PVP)was used as surfactant to prepare nano silver particles with particle size mainly distributed at 30 nm by liquid phase reduction method at room temperature.Using this as a conductive filler,the optimal ratio of conductive inks meeting the requirements of micro-write direct writing technology was explored.The final prepared nano-silver conductive ink conductive fillers accounted for 37% by mass and 58 CP.In this paper,the nano-silver conduction was prepared on the epoxy resin substrate by micro-writing technology.The optimal micro-writing technology was found to have a direct writing speed of 20 mm/s and a direct writing pressure of 25 PSI.The single-layer nano-silver wire written under this process parameter has a line width of 200 ?m;the wire height is increased by a multi-step direct writing process,and the line width of the 1st,2nd,5th,8th,10 th,and 15 th layers is directly written.Line heights are 200 ?m,1.2 ?m,203 ?m,3.3 ?m,217 ?m,4.2 ?m,231 ?m,6.9 ?m,256 ?m,10.5 ?m,280 ?m,11.8 ?m,352 ?m,13.5 ?m,of which direct writing The 10-layer nano-silver wire is optimal in line shape with a line width of 280 ?m and a line height of 11.8 ?m.In this paper,the room temperature sintering process was used to control the conductivity of the straight-through wire.The optimum room temperature sintering process parameters were 0.2 mol/L chloride ion and 10 min sintering time.The variation of the conductivity of different straight-through layers under this process parameter was investigated.The average resistance of the 1st,3rd,5th,8th,and 10 th layers of nano-silver wires are: 2.31 ?/cm,1.68 ?/cm,1.01 ?/cm,0.51 ?/cm,and 0.30 ?/cm,respectively.In this paper,the sintering process at room temperature was observed by SEM and TEM,and the sintering process was simplified into two stages.In the first stage,the interaction between the chloride ion and the silver particle is stronger,thereby destroying the Ag-O chemical bonding between the silver particle and the PVP,so that the nano silver particle is exposed to soften and form an original contact;afterwards,due to the high surface activity and surface of the nanoparticle The surface of the nano-silver particles can be diffused to provide a sintering driving force to form a joint.During the sintering process,the crystal plane orientation is the orientation of the crystal plane in the original contact,but the bonding strength of the different crystal planes is different,and the surface energy is Highest sintering strength when(111)interconnected.