Transversely-excited film bulk acoustic resonator package and method

An acoustic resonator device comprising:

• an acoustic resonator chip comprising:
• a substrate having front and back surfaces, a cavity formed in the front surface;
• a piezoelectric plate having front and back surfaces, the back surface attached to the front surface of the substrate except for a portion of the piezoelectric plate that forms a diaphragm spanning the cavity;
• a first conductor pattern formed as one or more conductor layers on the front surface of the piezoelectric plate, the first conductor pattern including:
• an interdigitated transducer (IDT) comprising two bus bars and interleaved fingers, the interleaved fingers of the IDT disposed on the diaphragm,
• the piezoelectric plate and IDT configured so that a radio frequency or microwave signal applied between the two busbars excites a bulk shear acoustic wave within the diaphragm;
• and
• a first plurality of contact pads;
• an interposer comprising:
• a base having front and back surfaces;
• and
• a second conductor pattern formed on the back surface of the base, the second conductor pattern including:
• a second plurality of contact pads;
• and
• a ring-shaped seal connecting a perimeter of the piezoelectric plate to a perimeter of the base, wherein
• each contact pad of the first plurality of contact pads is directly bonded to a respective contact pad of the second plurality of contact pads.

A filter device, comprising:

• an acoustic resonator chip comprising:
• a substrate;
• a piezoelectric plate having parallel front and back surfaces, the back surface attached to the substrate;
• and
• a conductor pattern formed on the front surface, 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 on respective portions of the piezoelectric plate suspended over one or more cavities formed in the substrate;
• a first thickness of a first dielectric layer deposited between the fingers of the IDT of a first resonator of a respective plurality of resonators;
• and
• a second thickness of a second dielectric layer deposited between the fingers of the IDT of a second resonator of a respective plurality of resonators;
• and
• an interposer comprising:
• a base having front and back surfaces;
• and
• a second conductor pattern formed on the back surface of the base, the second conductor pattern including:
• a second plurality of contact pads;
• and
• a ring-shaped seal connecting a perimeter of the piezoelectric plate to a perimeter of the base, wherein
• each contact pad of the first plurality of contact pads is directly bonded to a respective contact pad of the second plurality of contact pads.