Ultrasonic sensing device
AssigneeInvenSense, Inc.
InventorsRenata Melamud Berger, Julius Ming-Lin Tsai, Stephen Lloyd
Life of this patent
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Abstract
An electronic device comprises a CMOS substrate having a first surface and a second surface opposite the first surface. A plurality of ultrasonic transducers is provided having a transmit/receive surface. A contact surface is piezoelectrically associated with the plurality of ultrasonic transducers and is formed on the first surface of the CMOS substrate. The plurality of ultrasonic transducers is disposed on the second surface of the CMOS substrate, with the transmit/receive side attached to the second surface thereof such that the CMOS substrate is between the plurality of ultrasonic transducers and the platen. An image sensing system is also provided, together with a method for ultrasonic sensing in the electronic device.
Claims15
An electronic device comprising:
- a CMOS substrate having a first surface and a second surface opposite the first surface;
- a two-dimensional array of Piezoelectric Micromachined Ultrasonic Transducer (PMUT) devices, wherein each PMUT device is independently operable to generate and receive ultrasonic signals, and wherein the two-dimensional array of PMUT devices is disposed on the second surface of the CMOS substrate, wherein at least one PMUT device comprises:
- an edge support structure connected to the CMOS substrate;
- and
- a membrane connected to the edge support structure such that a cavity is defined between the membrane and the CMOS substrate, the membrane configured to allow movement at ultrasonic frequencies, the membrane comprising:
- a piezoelectric layer;
- first and second electrodes coupled to opposing sides of the piezoelectric layer;
- and
- a mechanical support layer;
- and
- a contact surface piezoelectrically associated with the two-dimensional array of PMUT devices and disposed on the first surface;
- wherein the CMOS substrate is between the two-dimensional array of PMUT devices and the contact surface such that the ultrasonic signals are emitted from the two-dimensional array of PMUT devices through the CMOS substrate toward the contact surface and reflected ultrasonic signals travel through the CMOS substrate for receipt at the two-dimensional array of PMUT devices.
A mobile electronic device comprising:
- a host processor;
- a host memory;
- and
- an ultrasonic sensor comprising:
- a CMOS substrate having a first surface and a second surface opposite the first surface, the CMOS substrate comprising logic, control, and communication electronics;
- a plurality of Piezoelectric Micromachined Ultrasonic Transducer (PMUT) devices formed on the second surface of the CMOS substrate, each PMUT device independently operable to emit and receive acoustic waves, wherein at least one PMUT device comprises:
- an edge support structure connected to the CMOS substrate;
- and
- a membrane connected to the edge support structure such that a cavity is defined between the membrane and the CMOS substrate, the membrane configured to allow movement at ultrasonic frequencies, the membrane comprising:
- a piezoelectric layer;
- first and second electrodes coupled to opposing sides of the piezoelectric layer;
- and
- a mechanical support layer connected to the first electrode;
- and
- a platen formed over the first surface;
- wherein the CMOS substrate is between the plurality of PMUT devices and the platen such that the acoustic waves are emitted from the plurality of PMUT devices through the CMOS substrate toward the platen and reflected acoustic waves travel through the CMOS substrate for receipt at the plurality of PMUT devices.
A method for ultrasonic sensing using an electronic device, the method comprising:
- providing a CMOS substrate having a first surface and a second surface opposite the first surface;
- forming a two-dimensional array of Piezoelectric Micromachined Ultrasonic Transducer (PMUT) devices, wherein each PMUT device is independently operable to generate and receive ultrasonic signals, and wherein the two-dimensional array of PMUT devices is disposed on the second surface of the CMOS substrate, wherein at least one PMUT device comprises:
- an edge support structure connected to the CMOS substrate;
- and
- a membrane connected to the edge support structure such that a cavity is defined between the membrane and the CMOS substrate, the membrane configured to allow movement at ultrasonic frequencies, the membrane comprising:
- a piezoelectric layer;
- first and second electrodes coupled to opposing sides of the piezoelectric layer;
- and
- a mechanical support layer;
- and
- forming a platen on the first surface and having a contact surface piezoelectrically associated with the two-dimensional array of PMUT devices,
- wherein the CMOS substrate is between the two-dimensional array of PMUT devices and the platen such that the ultrasonic signals are emitted from the two-dimensional array of PMUT devices through the CMOS substrate toward the contact surface and reflected ultrasonic signals travel through the CMOS substrate for receipt at the two-dimensional array of PMUT devices.
Dependencies are inferred from the claim text.