PIEZOELECTRIC SENSOR DEVICE

摘要

Disclosed is a piezoelectric sensor device with which reduction in device size can be achieved and in which costs can be reduced without requiring precise fixing of the piezoelectric detection element and without needing to provide a space on the opposite side to the detection face. One side face of a piezoelectric detection element (2) of the enclosed energy type is designated as the detection face and a holding member (7) is laminated, with interposition of a joining layer (6), on the face on the opposite side to this detection face. If the acoustic impedance value of the piezoelectric detection element (2) is identified as the first acoustic impedance value Z1, the acoustic impedance value of the joining layer (6) is identified as the second acoustic impedance value Z2, and the acoustic impedance value of the holding member (7) is identified as the third acoustic impedance value Z3, then, for this piezoelectric sensor device (1), it is specified that: Z1 > Z2 < Z3.