An
improved method for depositing ferroelectric particles on a surface of a substrate to form films or stand-alone bodies. The improvement is based on
electrophoretic deposition (EPD) of ferroelectric films by using a tri-functional
phosphate ester additive having a concentration less than 10
volume percent in the EPD suspension, without the need for addition of a binder. The method includes preparation of the suspension by washing and dispersing ferroelectric particles, for example, commercially available PZT
powder, in a polar
solvent such as
ethanol, followed by addition of the
phosphate ester additive to the suspension, and an
ultrasound treatment. The suspension is used in EPD of the ferroelectric particles on a prepared substrate. Following EPD, the green film is dried and sintered at high temperature. Visual and
physical examination of stand alone and patterned PZT deposited films show excellent quality obtained in manufacturing a diversity of piezoelectric products, featuring exceptionally high green film uniformity, thickness distribution, and reproducibility to within + / -2 microns for 20
micrometer film thickness. The
phosphate ester additive functions by improving stabilization and control of suspension characteristics and properties during the electrophoretic migration process, and by improving desired dimensions, characteristics, and electrical properties of the deposited green film. Thin or thick ferroelectric films, either as stand alone products, or formed on geometrically demanding patterned or non-patterned substrates are produced by using the method. The
improved method is applicable to different ferroelectric particulate materials and to different substrates used for manufacturing piezoelectric elements and devices, in a cost effective manner.