Thermal and laser sintering of a highly stable inkjet ink consisting of silver nanoparticles stabilized by a combination of a short chain carboxylic acid and a polymeric dispersant

A mixture of silver nanoparicles and its organic salt has been used for the development of conductive inks for inkjet printing. Silver nanoparticles stabilized with butanoic acid (C4) with the average size of 11.1 +/- 2.4 nm have been synthesized via the reduction of solid silver carboxylate with hydrazine hydrate in benzyl alcohol. An inkjet ink formulation consisting of the silver nanoparticles capped with butanoic acid (up to 50 wt.%) with the addition of polymeric BYK dispersant in a mixture of nontoxic solvents with different boiling temperatures and different polarities has been developed and its physical properties and stability have been studied. Silver layers were spin coated and printed on a polyimide film using the developed ink. Experiments on the thermal annealing of the silver films showed that the curing temperature can be below 200 degrees C to obtain a layer having the electrical resistivity less than 10 mu Omega xcm. A study of the laser sintering of the printed and spin coated elements on a polyimide film using a diode laser operating at 453 nm in impulse mode showed that the best mode is a multi-pass sintering, which can be divided into two steps: the evaporation of the solvent and sintering of the silver nanoparticles. (c) 2018 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of 10th International Symposium on Flexible Organic Electronics (ISFOE17).