Preparation of BaTiO3 Thick Films by Inkjet Printing on Oxygen-Plasma-Modified Substrates

Thick film patterns were prepared by an inkjet method with water-based ink containing BaTiO 3 powder. An ethyl cellulose layer was made over Pt electrodes, and oxygen plasma modification was performed. After this modification, patterns on substrates were printed in shape. The measurement of the contact angle of ink on the ethyl cellulose layer and the X-ray photoelectron spectroscopy of the ethyl cellulose layer were carried out. From the obtained results, wettability was determined to be improved by increasing the number of hydrophilic functional groups on the surface of ethyl cellulose layer. Surface observation using a scanning electron microscope was carried out on a modified ethyl cellulose layer. Surface roughness due to the etching effect of oxygen plasma was observed to increase with modification time. After firing at 1340 °C for 1 h, the BaTiO 3 film thickness was approximately 30 µm. The electric properties of BaTiO 3 films were examined. The dielectric constant and tan δ were 2200 and 0.05 at 1 kHz, respectively. The remanent polarization and coercive field measured from a P – E hysteresis curve were 3.1 µC/cm 2 and 1.1 kV/cm, respectively. These results indicate that an inkjet printing method using a modified EC layer is applicable to the fabrication of thick films on substrates.