Piezoelectric actuator, piezoelectric vibration apparatus and portable terminal having a region that is not flat for bonding to a flexible substrate

摘要

A piezoelectric actuator, a piezoelectric vibration apparatus and a portable terminal are disclosed. The actuator includes a piezoelectric element, a flexible substrate and a bonding layer. The piezoelectric element includes a laminate in which inner electrodes and piezoelectric layers are alternatively stacked; and surface electrodes on a first main surface of the laminate, each electrically connected to some of the inner electrodes, respectively. The flexible substrate includes a wiring conductor that is electrically connected to the surface electrodes. The bonding layer is located between a part of flexible substrate and the first main surface. At least a region, where the flexible substrate is bonded, of the first main surface has a flatness worse than a flatness of an second main surface which is opposed to the first main surface.