Research of 3D Printing Technology for Silver Paste based on Direct Ink Writing

Flexible electronics devices have many advantages, such as portability, transparency, good stretching and bending ability. In recent years, with the growing demand of the flexible electronics, it promoting the innovation of manufacturing method. Direct ink writing (DIW) is a low-cost, flexible and efficiency method to patterning conductive circuits on the flexible substrate. In this paper, Direct ink writing of commercial silver paste on PI substrates is introduced and the parameters that can be modified to tune the process include feed pressure, dispensing gap, moving speed and nozzle size are discussed. The results show that the commercial silver paste based on DIW method can obtain minimal trace width of 151μm on PI substrates under 0.11mm inner diameter nozzle, 100mm/min moving speed, 0.15Mpa feed pressure and 0.07mm dispensing gap. Then using the five-axis micro pen direct writing device developed by Ruite 3D, the silver paste pattern was successfully printed on the curved surface, which provided a useful reference for the subsequent application of the silver paste DIW technology in conformal antennas, flexible wearable devices and other 3D circuit fabrication directions.