Piezoelectric ceramic plates are used for a variety of electronic components, such as a piezoelectric actuator, which utilize, as a mechanical driving source, displacement or force generated via a piezoelectric phenomenon. With broadened use of piezoelectric actuators, multi-layer piezoelectric actuators from which larger displacement or larger generated force can be obtained at lower voltages have become increasingly used.
Since conventional piezoelectric ceramic plates develop significant deformation (variation in shrinkage) after firing, such piezoelectric ceramic plates are subjected to processing, such as cutting and polishing, after firing in order to control the shape and dimensions of the piezoelectric ceramic plates into prescribed ranges (see, for example, Patent Literature 1).