Ultrasonic Spray Coated Silver Layers

Ultrasonic spray coated silver layers from designed precursor inks for flexible electronics

Integrating electronic circuit components onto flexible materials such as plastic foil, paper and textiles is a key challenge for the development of future intelligent applications. Therefore, there is a need to deposit conductive metal features on temperature-sensitive substrates in a fast and straightforward manner. The feasibility of these emerging (nano) electronic technologies depends on the availability of well-designed deposition techniques and novel functional metallic inks. Since ultrasonic spraying is one of the most promising technologies to meet the above requirements, the innovative metal organic decomposition ink is designed to deposit silver features on plastic foil. Various amine ligands were screened and their effects on ink stability and properties of the resulting metal deposits were evaluated to determine the best formulation. Finally, when working in the extremely low temperature range of 70 ° C–120 ° C, a silver layer with excellent electrical conductivity (15% volume silver electrical conductivity), stability, morphology and adhesion can be obtained. In addition, the in-depth analysis of the ultrasonic sprayed silver layer determined the optimal deposition conditions. Using these tailor-made metal organic decomposition inks, ultrasonic spray technology can form a smooth, translucent silver layer with adjustable thickness over a large area without the need for additional sintering steps after deposition. Therefore, the novel combination of this nanoparticle-free silver ink and ultrasonic spraying process provides hope for high-flux deposition of highly conductive silver features on highly heat-sensitive substrates and even 3D objects.