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US 11,376,628 B2Granted
Capacitive device and piezoelectric device
AssigneeHitachi, Ltd.
InventorsTaiichi Takezaki, Hiroaki Hasegawa, Shuntaro Machida
Life of this patent
Estimating the term…
Abstract
A capacitive device includes a unit cell including a CMUT, and a transmission/reception plate for impedance matching which is provided above the unit cell via a connection portion, in which a membrane of the CMUT constituting the unit cell is connected to the transmission/reception plate via the connection portion having an area smaller than that of the transmission/reception plate. The area of the transmission/reception plate is desirably larger than the area of a hollow portion of the CMUT.
Claims3
A capacitive device comprising:
- an ultrasonic transducer comprising:
- a substrate,
- a lower electrode formed above the substrate,
- a hollow portion provided above a first insulating film and below a second insulating film sequentially formed above the lower electrode,
- an upper electrode formed above the hollow portion,
- a third insulating film formed above the upper electrode, and
- a membrane constituted by the second insulating film and the third insulating film above the hollow portion;
- a connection portion formed on the membrane and having a first area;
- and
- a transmission/reception plate formed above the ultrasonic transducer via the connection portion and having a second area larger than the first area, wherein
- the second area of the transmission/reception plate is larger than an area of the hollow portion,
- the transmission/reception plate is fixed to the ultrasonic transducer via a fixed portion,
- the transmission/reception plate has a planar spiral shape, and
- the hollow portion, the membrane, and the connection portion are arranged at a position closer to the fixing portion than a center portion of the transmission/reception plate.
11 more elements
Dependencies are inferred from the claim text.