Electrophoretic deposition and characterization of micrometer-scale BaTiO3 based X7R dielectric thick films

Uniform and relatively dense BaTiO3 thick films of 1-5 mu m were prepared by an electrophoretic deposition process using submicrometer BaTiO3 powders (mean particle size: similar to 0.2 mu m). Two different BaTiO3 powders and solvent media were used to investigate the film quality and thickness control. The surface charge mechanism of BaTiO3 particles was explained according to the observed results. The microstructures were examined by means of SEM. The experimental results show that the thickness could be controlled independently of suspension concentration by keeping a constant applied voltage and a constant current drop in a given suspension. BaTiO3 thick films have good insulation resistance and dielectric properties such as a dielectric constant and a dissipation factor that are compatible with the data from conventional tape-cast BaTiO3 thin layers.