US 12,407,326 B2
Stacked die transversely-excited film bulk acoustic resonator (XBAR) filters
James R. Costa, Grass Valley, CA (US)
Assigned to Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Sep. 2, 2022, as Appl. No. 17/902,616.
Claims priority of provisional application 63/275,870, filed on Nov. 4, 2021.
Prior Publication US 2023/0134889 A1, May 4, 2023
Int. Cl. H03H 9/56 (2006.01); H03H 3/02 (2006.01); H03H 9/13 (2006.01); H03H 9/17 (2006.01)
CPC H03H 9/564 (2013.01) [H03H 3/02 (2013.01); H03H 9/133 (2013.01); H03H 9/173 (2013.01); H03H 9/568 (2013.01); H03H 2003/021 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A stacked die XBAR filter device comprising:
a first die containing one or more shunt XBARs on a first surface, the one or more shunt XBARs having a first piezoelectric layer with a first thickness T1 and a first interdigital transducer having interleaved fingers on the first piezoelectric layer;
a second die containing one or more series XBARs on a second surface, the one or more series XBARs having a second piezoelectric layer with a second thickness T2 that is less than the first thickness T1 and a second interdigital transducer having interleaved fingers on the second piezoelectric layer; and
one or more conductive vias through either the first die or the second die,
wherein the first die is connected to the second die with the first surface facing the second surface, and
wherein the interleaved fingers of the first interdigital transducer have a different thickness than the interleaved fingers of the second interdigital transducer.