Polymer nanocomposites for screen printed electronic connections

Printed electronics makes possible to produce flexible electronic connections using printing techniques. This causes that printed items can be applied even on corrugated surfaces without any damages or changes in their properties. However, it is necessary to elaborate new materials which exhibited high flexibility. According to the results of investigations described in the literature nanomaterials, especially carbon nanotubes, allow to increase flexibility of printed layers. In the study, polymer nanocomposites for screen printed electronic interconnections were investigated. Carbon nanotubes, carbon nanofibres and silver nanopowder were used as fillers for elaborating of conductive pastes. Poly(methyl methacrylate) (PMMA), poly(methyl methacrylate)-poly(butyl methacrylate) (PMMA-PBMA) or conductive polymer PEDOT:PSS were applied as a carrier which was dissolved in an organic solvent butyl carbitol acetate. Elaborated polymer nanocomposites were printed on flexible substrate, like foil or paper. The resistance of specimens made with the paste with silver nanopowder was the lowest achieved value (below 100 mΩ/□). For the other pastes, it was equal significantly to above 150 Ω/□ and changed depending on a number of printed layers. The printed layers were also evaluated in terms of their durability to mechanical stresses. The smallest increase (2.65 %) in sheet resistance after 1000 bending cycles was observed for the layer printed with the paste containing silver nanopowder.