Resonant Inc.
TRANSVERSELY-EXCITED FILM BULK ACOUSTIC RESONATOR PACKAGE

Abstract:

Acoustic resonator devices and filters; and methods of their fabrication are disclosed. A piezoelectric plate is bonded to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity that is formed in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer disposed on the diaphragm, and a first plurality of contact pads. A second conductor pattern is formed on a back surface of an interposer, the second conductor pattern including a second plurality of contact pads. The interposer is formed by cofiring layers of thin ceramic tape, at least one layer of the tape comprising printed conductors. A plurality of conductive balls is formed on and directly bonds the first plurality of contact pads to respective contact pads of the second plurality of contact pads.