Together with collaborators from Lappeenranta-Lahti University of Technology LUT, Zhao Fu et al. conducted a research to investigate the impact of load and rubbing material on the reliability and failure mechanism of inkjet-printed silver nanoparticle conductor on the flexible paperboard materials by using wear tests. The conductor’s reliability was characterized by resistance measurement, the failures and tested counter materials were analyzed using an optical microscope, profilometer, Scanning Electron Microscope (SEM), and Energy Dispersive Spectrometer (EDS).
The main findings / highlights are:
1) The counter material has a dominant impact on the counter’s reliability and failure mechanism compared with load.
2) The conductors were exceptionally reliable but subject to adhesive wear when tested by paperboards. They were also highly reliable when tested by brushed steel sheet although the silver became severely detached, and the conductivity was lost suddenly when a major scratch was caused by two-body and three-body abrasive wear mechanisms.
3) Sandpaper rubbing caused the most severe silver detachment and quick loss of conductivity, as a large amount of small-size (5 – 15 µm) silicon carbide (SiC) particles with sharp edges and corners caused a dense cutting effect via two-body abrasive wear (by cutting) mechanism.
4) The failures in all cases were accelerated by the edge effect.
5) This study proves that inkjet-printed electronics on the investigated paperboard is exceptionally durable when rubbed by paperboards and steel sheets, and thus provides a reliable solution to intelligent packaging.