Method of electrophoretic deposition of ferroelectric films using a trifunctional additive and compositions for effecting same
US6127283A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1999 |
| Grant date | Oct 3, 2000 |
| Priority date | — |
| Expiry date | Nov 2, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/097
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
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 stabi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.