Morphological influences on the electrical sintering process of Aerosol Jet and Ink Jet printed silver microstructures

The morphology of non-sintered printed structures depends on the applied printing process. Aerosol Jet and Ink Jet printed silver structures have been post-treated by furnace and electrical sintering. The resulting different morphologies of the structures were investigated optically by scanning electron microscopy and electrically by measuring the specific electrical resistances. Aerosol Jet printed silver required higher temperature during furnace sintering compared to Ink Jet printed structures to reach the same specific resistance. At temperatures above 200 °C an influence of the printing process on the final electrical resistance was not observed anymore. The electrical sintering with direct current of Aerosol Jet and Ink Jet printed silver microstructures showed lower specific resistances for the aerosol generated structures. Electrical sintering was extended by an electronic regulator module (ERM), which allows the sintering of the printed structures to a specified target resistance. While the average resistance of the structures is depending on accurate adjustment of the ERM, the maximum standard deviation of the resistance values is only 2 % which is much better than in conventional sintering.