Transversely-excited film bulk acoustic resonator package

An acoustic resonator device comprising:

• an acoustic resonator chip comprising:
• a substrate having a surface;
• a piezoelectric layer attached to the surface of the substrate either directly or via one or more intermediate layers, the piezoelectric layer having portions that form at least two diaphragms over at least two cavities;
• a first conductor pattern comprising one or more conductor layers at the piezoelectric layer, the first conductor pattern including:
• at least two interdigital transducers (IDTs) comprising two bus bars and interleaved fingers, the interleaved fingers of each of the at least two IDTs disposed at respective diaphragms of the at least two diaphragms, wherein the piezoelectric layer and the at least two IDTs are configured so that a radio frequency or microwave signal applied between the two busbars excites a bulk shear acoustic wave in the at least two diaphragms;
• and
• a first plurality of contact pads;
• an interposer comprising:
• layers of a low temperature cofired ceramic (LTCC) circuit card, at least one layer of the LTCC circuit card comprising printed conductors;
• interposer front and back surfaces;
• and
• a second conductor pattern at the interposer back surface, the second conductor pattern including a second plurality of contact pads;
• and
• a plurality of conductive balls directly connecting first ones of the contact pads of the first plurality of contact pads to respective contact pads of the second plurality of contact pads.

A filter device, comprising:

• an acoustic resonator chip comprising:
• a substrate;
• a piezoelectric layer attached to the substrate either directly or via one or more intermediate layers;
• and
• a conductor pattern at the piezoelectric layer, the conductor pattern including a plurality of interdigital transducers (IDTs) of a respective plurality of resonators and a first plurality of contact pads, wherein:
• interleaved fingers of each of the plurality of IDTs are disposed at respective portions of the piezoelectric layer over one or more cavities;
• a first dielectric layer having a first thickness is disposed on and between the fingers of a respective IDT of a first resonator of a respective plurality of resonators;
• a second dielectric layer having a second thickness is disposed on and between the fingers of a respective IDT of a second resonator of a respective plurality of resonators;
• and
• the respective portions of the piezoelectric layer are two separate portions of a piezoelectric layer that are separated by an etched trench through the piezoelectric layer;
• and
• an interposer comprising:
• layers of a low temperature cofired ceramic (LTCC) circuit card, at least one layer of the LTCC circuit card comprising printed conductors;
• interposer front and back surfaces;
• and
• a second conductor pattern at the interposer back surface, the second conductor pattern including a second plurality of contact pads;
• and
• a plurality of conductive balls directly connecting first ones of the contact pads of the first plurality of contact pads to respective contact pads of the second plurality of contact pads.