US 12,302,047 B2
Transducer and electronic device
Takashi Naiki, Kyoto (JP); Noriyuki Shimoji, Kyoto (JP); and Tomohiro Date, Kyoto (JP)
Assigned to ROHM CO., LTD., Kyoto (JP)
Filed by ROHM CO., LTD., Kyoto (JP)
Filed on Jul. 26, 2022, as Appl. No. 17/815,009.
Application 17/815,009 is a continuation of application No. PCT/JP2021/003328, filed on Jan. 29, 2021.
Claims priority of application No. 2020-016079 (JP), filed on Feb. 3, 2020; and application No. 2020-022510 (JP), filed on Feb. 13, 2020.
Prior Publication US 2022/0360871 A1, Nov. 10, 2022
Int. Cl. H04R 1/02 (2006.01); H04R 17/00 (2006.01); H10N 30/20 (2023.01); H10N 30/87 (2023.01)
CPC H04R 1/02 (2013.01) [H04R 17/00 (2013.01); H10N 30/2043 (2023.02); H10N 30/872 (2023.02)] 15 Claims
OG exemplary drawing
 
1. A transducer comprising:
a film support portion having a hollow portion;
a vibration film connected to the film support portion and displaceable in a film thickness direction of the film support portion;
a piezoelectric element on the vibration film, the piezoelectric element including a pair of electrodes and a piezoelectric film sandwiched between the pair of electrodes; and
in regions overlapping the hollow portion, a plurality of first regions having a first total film thickness of the first regions which is a sum of a film thickness of the vibration film and a film thickness of the piezoelectric element in the first regions, and a plurality of second regions having a second total film thickness of the second regions which is a sum of a film thickness of the vibration film and a film thickness of the piezoelectric element in the second regions, the second total film thickness being different from the first total film thickness, wherein
the first regions and the second regions are alternately arranged, and
one of the first regions is adjacent to a connection portion between the film support portion and the vibration film.
 
5. A transducer comprising:
a film support portion having a hollow portion;
a vibration film connected to the film support portion and displaceable in a film thickness direction of the film support portion;
a piezoelectric element on the vibration film, the piezoelectric element including a pair of electrodes, a piezoelectric film sandwiched between the pair of electrodes, and a plurality of buffer layers on the pair of electrodes; and
in regions overlapping the hollow portion, first regions configured not to include the buffer layers, and second regions configured to include the buffer layers, wherein
the first regions and the second regions are alternately arranged, and
one of the first regions is adjacent to a connection portion between the film support portion and the vibration film.
 
14. A transducer comprising:
a film support portion having a hollow portion;
a vibration film connected to the film support portion and displaceable in a film thickness direction of the film support portion; and
a piezoelectric element on the vibration film, the piezoelectric element including a pair of electrodes and a piezoelectric film sandwiched between the pair of electrodes; wherein
the vibration film includes a plurality of recesses,
in regions overlapping the hollow portion, the transducer includes first regions configured not to include the recesses, and second regions configured to include the recesses,
the first regions and the second regions are alternately arranged,
one of the first regions is adjacent to a connection portion between the film support portion and the vibration film, and
one of the second regions is parallel to the connection portion.