US 12,170,513 B2
Transversely-excited film bulk acoustic resonator with reduced substrate to contact bump thermal resistance
Albert Cardona, Santa Barbara, CA (US); Chris O'Brien, Santa Barbara, CA (US); and Greg Dyer, Santa Barbara, CA (US)
Assigned to Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Oct. 20, 2021, as Appl. No. 17/506,571.
Claims priority of provisional application 63/216,525, filed on Jun. 30, 2021.
Prior Publication US 2023/0006640 A1, Jan. 5, 2023
Int. Cl. H03H 9/13 (2006.01); H03H 9/02 (2006.01); H03H 9/15 (2006.01); H03H 9/17 (2006.01); H03H 9/54 (2006.01); H03H 9/56 (2006.01); H10N 30/05 (2023.01); H10N 30/06 (2023.01); H10N 30/20 (2023.01)
CPC H03H 9/13 (2013.01) [H03H 9/02015 (2013.01); H03H 9/15 (2013.01); H03H 9/17 (2013.01); H03H 9/54 (2013.01); H03H 9/568 (2013.01); H10N 30/05 (2023.02); H10N 30/06 (2023.02); H10N 30/20 (2023.02)] 19 Claims
OG exemplary drawing
 
1. An acoustic resonator device with reduced substrate to contact bump thermal resistance, the acoustic resonator comprising:
a substrate having a surface;
a piezoelectric plate having front and back surfaces, the back surface attached to the surface of the substrate via a bonding oxide (BOX) layer over the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate;
a conductor pattern including an interdigital transducer (IDT) on the front surface of the piezoelectric plate such that interleaved fingers of the IDT are on the diaphragm;
contact pads disposed at selected locations over the surface of the substrate to provide electrical connections between the IDT and contact bumps to be attached to the contact pads; and
an electrically isolating layer disposed between the contact pads and the surface of the substrate,
wherein the piezoelectric plate is absent from at least a portion of a surface area of the acoustic resonator device beneath each of the contact pads to provide lower thermal resistance between the contact bumps to be formed on the acoustic resonator device and the substrate, and
wherein the BOX layer is absent from at least the portion of the surface area of the acoustic resonator device beneath each of the contact pads to provide lower thermal resistance between the contact bumps and the substrate.