| 摘要 |
<p>PURPOSE:To prevent the mechanical breakdown during polarizing treatment for piezoelectric ceramics and to improve the yield rate in manufacturing. CONSTITUTION:Heat treatment is performed for a long time for piezoelectric ceramics beforehand at a temperature higher than polarization treatment temperature. Immediately after the heat treatment, a DC voltage is applied, and the polarization treatment is performed. Since the applying time of the DC-voltage applying time required for the polarization treatment is greatly shortened, the discharging frequency during the polarization treatment is decreased, and the mechanical breakdowns of the piezoelectric ceramics caused by the discharge are decreased.</p> |
