PIEZOELECTRIC DEVICE, PIEZOELECTRIC TRANSFORMER, AND PIEZOELECTRIC DEVICE MANUFACTURING METHOD

摘要

A piezoelectric device (101) is provided with a base material (1), and an upper layer (2) supported by the base material (1). The upper layer (2) includes a vibration section (3), i.e., a portion (51) of the upper layer (2), said portion not overlapping the base material (1). The vibration section (3) includes a lower electrode (31), an intermediate electrode (32), and an upper electrode (33), which are disposed by being separated from each other in the thickness direction. The upper layer (2) includes: a first piezoelectric layer (4) that is disposed such that at least a part thereof is sandwiched between the lower electrode (31) and the intermediate electrode (32); and a second piezoelectric layer (5) that is disposed such that at least a part thereof is sandwiched between the intermediate electrode (32) and the upper electrode (33), while being disposed to overlap the first piezoelectric layer (4). The first piezoelectric layer (4) and the second piezoelectric layer (5) extend to a portion (52) where the upper layer (2) overlaps the base material (1), while extending to the vibration section (3) of the upper layer (2). The first piezoelectric layer (4) and the second piezoelectric layer (5) have different relative dielectric constants in the thickness direction.