Transversely-excited film bulk acoustic resonator package and method

An acoustic resonator device comprising:

• a radio frequency filter comprising:
• a substrate;
• a piezoelectric layer attached to the substrate either directly or via one or more intermediate layers;
• and
• a first conductor pattern on the piezoelectric layer and including an interdigitated transducer (IDT) with interleaved fingers and a first contact pad on the piezoelectric layer opposite the substrate;
• and
• an interposer having a planar surface facing the piezoelectric layer and a second conductor pattern with a second contact pad on the planar surface of the interposer that faces the piezoelectric layer,
• wherein the first conductor pattern is bonded to the second conductor pattern to form a seal to prevent an intrusion of fluids to an interior of the radio frequency filter, and
• wherein the seal couples a perimeter of the piezoelectric layer to a perimeter of the interposer.

An acoustic resonator device comprising:

• a substrate;
• a piezoelectric layer above the substrate and including a diaphragm that is suspended over a cavity between the piezoelectric layer and the substrate;
• a first conductor pattern on the piezoelectric layer and including an interdigitated transducer (IDT) with interleaved fingers on the diaphragm and a first contact pad;
• an interposer having a planar surface facing the piezoelectric layer and a second conductor pattern with a second contact pad on the planar surface of the interposer that face the piezoelectric layer;
• and
• a metal seal formed by the first conductor pattern being bonded to the second conductor pattern and that couples the acoustic resonator chip to the interposer,
• wherein the interposer is a printed circuit board that comprises a plurality of vias that connect the second contact pad to a third contact pad on a surface of the interposer opposite the planar surface of the interposer that faces the piezoelectric layer.