Piezoelectric sensor with increased sensitivity and devices having the same

Patent metadata

Field	Value
Publication number	US-12329033-B2
Application number	US-202218047443-A
Country	US
Kind code	B2
Filing date	Oct 18, 2022
Priority date	Oct 21, 2021
Publication date	Jun 10, 2025
Grant date	Jun 10, 2025

Abstract

A piezoelectric sensor (e.g., for use in a piezoelectric MEMS microphone) includes a substrate and a cantilever beam attached to the substrate. The cantilever beam has a proximal portion attached to the substrate and extending to an unsupported distal end. An electrode is disposed on or in the proximal portion of the beam and has an outer boundary with a shape substantially corresponding to a contour line of a strain distribution plot for the cantilever beam resulting from a force applied to the cantilever beam.

First claim

What is claimed is:

1. A piezoelectric sensor, comprising:
a substrate;
a cantilever beam having a proximal portion attached to the substrate and extending to an unsupported distal end of the beam; and
an electrode disposed on or in the proximal portion of the beam, the electrode having an outer boundary with a shape substantially corresponding to a contour line of a strain distribution plot for the cantilever beam resulting from a force applied to the cantilever beam.

2. The sensor of claim 1 wherein the cantilever beam is a triangular beam, the unsupported distal end being a distal tip of the triangular beam.

3. The sensor of claim 1 wherein at least a portion of two edges of the outer boundary of the electrode are disposed inward of a pair of outer edges of the cantilever beam.

4. The sensor of claim 1 wherein two corners of the proximal portion of the cantilever beam are not covered by the electrode.

5. The sensor of claim 1 wherein at least a portion of the outer boundary of the electrode is non-linear.

6. The sensor of claim 1 wherein the cantilever beam has a rectangular shape.

7. A piezoelectric microelectromechanical systems microphone, comprising:
a substrate; and
a plurality of piezoelectric sensors movably coupled to the substrate, each of the piezoelectric sensors spaced apart from an adjacent piezoelectric sensor by a gap and including: a cantilever beam having a proximal portion attached to the substrate and extending to an unsupported distal end of the beam, and an electrode disposed on or in the proximal portion of the beam, the electrode having an outer boundary with a shape substantially corresponding to a contour line of a strain distribution plot for the cantilever beam resulting from a force applied to the cantilever beam, the plurality of piezoelectric sensors configured to deflect when subjected to sound pressure.

8. The microphone of claim 7 wherein the cantilever beam is a triangular beam, the unsupported distal end being a distal tip of the triangular beam.

9. The microphone of claim 7 wherein at least a portion of two edges of the outer boundary of the electrode are disposed inward of a pair of outer edges of the cantilever beam.

10. The microphone of claim 7 wherein two corners of the proximal portion of the cantilever beam are not covered by the electrode.

11. The microphone of claim 7 wherein at least a portion of the outer boundary of the electrode is non-linear.

12. The microphone of claim 7 wherein the cantilever beam has a rectangular shape.

13. An audio subsystem, comprising:
an audio codec; and
one or more piezoelectric microelectromechanical systems microphones in communication with the audio codec, each microphone including: a substrate and a plurality of piezoelectric sensors movably coupled to the substrate, each of the piezoelectric sensors spaced apart from an adjacent piezoelectric sensor by a gap and including a cantilever beam having a proximal portion attached to the substrate and extending to an unsupported distal end of the beam, and an electrode disposed on or in the proximal portion of the beam, the electrode having an outer boundary with a shape substantially corresponding to a contour line of a strain distribution plot for the cantilever beam resulting from a force applied to the cantilever beam.

14. The audio subsystem of claim 13 wherein the cantilever beam is a triangular beam, the unsupported distal end being a distal tip of the triangular beam.

15. The audio subsystem of claim 13 wherein at least a portion of two edges of the outer boundary of the electrode are disposed inward of a pair of outer edges of the cantilever beam.

16. The audio subsystem of claim 13 wherein two corners of the proximal portion of the cantilever beam are not covered by the electrode.

17. The audio subsystem of claim 13 wherein at least a portion of the outer boundary of the electrode is non-linear.

18. The audio subsystem of claim 13 wherein the cantilever beam has a rectangular shape.

Assignees

• Skyworks Solutions Inc

Inventors

• Qian You
• Campanella-Pineda Humberto
• Chen Guofeng
• Kumar Rakesh

Classifications

• H04R2201/003

  Mems transducers or their use · CPC title

• H04R17/02

  Microphones · CPC title

• H04R7/10

  comprising superposed layers in contact · CPC title

• H04R3/005

  for combining the signals of two or more microphones (specially adapted for hearing aids H04R25/407) · CPC title

• H10N30/302

  Sensors · CPC title