Piezoelectric thin film device having a drive section with a weighted portion

Abstract

There is provided a piezoelectric thin film device with its frequency impedance characteristic unsusceptible to spuriousness. A film bulk acoustic resonator has a configuration where an adhesive layer, a lower electrode, a piezoelectric thin film, and an upper electrode are laminated in this order on a support substrate. A drive section of the upper electrode and a drive section of the lower electrode are opposed to each other with the piezoelectric thin film interposed therebetween. The respective drive section has a slender two-dimensional shape, with magnitude in its longitudinal direction being not less than twice, more desirably four times, and further desirably ten times, as large as magnitude in its widthwise direction.

Dependencies are inferred from the claim text.