Piezoelectric microelectromechanical system corrugated microphone

Patent metadata

Field	Value
Publication number	US-12212925-B2
Application number	US-202217879933-A
Country	US
Kind code	B2
Filing date	Aug 3, 2022
Priority date	Aug 4, 2021
Publication date	Jan 28, 2025
Grant date	Jan 28, 2025

Abstract

A piezoelectric microelectromechanical system microphone comprises a support substrate, a piezoelectric element configured to deform and generate an electrical potential responsive to impingement of sound waves on the piezoelectric element, the piezoelectric element attached to the support substrate about a perimeter of the piezoelectric element, a sensing electrode disposed on the piezoelectric element and configured to sense the electrical potential, and corrugations defined in the piezoelectric element about the perimeter of the piezoelectric element to release residual stress and improve sensitivity of the piezoelectric microelectromechanical system microphone.

First claim

What is claimed is:

1. A piezoelectric microelectromechanical system microphone comprising:
a support substrate;
a piezoelectric element configured to deform and generate an electrical potential responsive to impingement of sound waves on the piezoelectric element, the piezoelectric element attached to the support substrate about a perimeter of the piezoelectric element;
a sensing electrode disposed on the piezoelectric element and configured to sense the electrical potential; and
corrugations defined in the piezoelectric element about the perimeter of the piezoelectric element to release residual stress and improve sensitivity of the piezoelectric microelectromechanical system microphone.

2. The piezoelectric microelectromechanical system microphone of claim 1 wherein the piezoelectric element has a diaphragm structure.

3. The piezoelectric microelectromechanical system microphone of claim 2 wherein the piezoelectric element is circular.

4. The piezoelectric microelectromechanical system microphone of claim 2 wherein the corrugations are defined in an anchor region of the diaphragm structure.

5. The piezoelectric microelectromechanical system microphone of claim 4 wherein the corrugations include portions of the piezoelectric element displaced from one another in a direction normal to a plane defined by the perimeter of the piezoelectric element.

6. The piezoelectric microelectromechanical system microphone of claim 5 wherein the corrugations further include a trench defined in the piezoelectric element.

7. The piezoelectric microelectromechanical system microphone of claim 5 wherein the corrugations further include a plurality of trenches defined in the piezoelectric element.

8. The piezoelectric microelectromechanical system microphone of claim 2 wherein the sensing electrode includes an inner sensing electrode disposed proximate a center of the diaphragm structure and an outer sensing electrode disposed proximate the perimeter of the diaphragm structure.

9. The piezoelectric microelectromechanical system microphone of claim 8 wherein the corrugations are defined in a region of the piezoelectric element surrounding the outer sensing electrode.

10. The piezoelectric microelectromechanical system microphone of claim 1 further comprising an elastic layer disposed on a lower surface of the piezoelectric element.

11. The piezoelectric microelectromechanical system microphone of claim 10 wherein the corrugations include portions of the elastic layer displaced from one another in a direction normal to a plane defined by the perimeter of the piezoelectric element.

12. The piezoelectric microelectromechanical system microphone of claim 11 wherein the corrugations further include a trench defined in the elastic layer.

13. The piezoelectric microelectromechanical system microphone of claim 1 further comprising a piezoelectric material layer disposed on a lower surface of the piezoelectric element.

14. The piezoelectric microelectromechanical system microphone of claim 13 wherein the corrugations include portions of the piezoelectric material layer displaced from one another in a direction normal to a plane defined by the perimeter of the piezoelectric element.

15. The piezoelectric microelectromechanical system microphone of claim 14 wherein the corrugations further include a trench defined in the piezoelectric material layer.

16. An electronic device module including the piezoelectric microelectromechanical system microphone of claim 1 .

17. An electronic device including the electronic device module of claim 16 .

18. A cellular telephone including the electronic device module of claim 16 .

19. A method of forming a piezoelectric microelectromechanical system microphone, the method comprising:
depositing a film of piezoelectric material on a support substrate, the film of piezoelectric material secured to the support substrate about a perimeter of the film of piezoelectric material and including a central region defined within the perimeter that is free to vibrate responsive to impingement of sound waves on the central region;
forming electrodes on one or both of upper and lower surfaces of the film of piezoelectric material within the central region; and
forming corrugations in the film of piezoelectric material in an anchor region of the film of piezoelectric material.

20. The method of claim 19 wherein forming the corrugations includes forming one or more trenches in the film of piezoelectric material.

Assignees

• Skyworks Global Pte Ltd

Inventors

• Hui Yu
• Chen Guofeng
• Shin Kwang Jae
• Gu Myeong Gweon

Classifications

• H04R17/02 Primary

  Microphones · CPC title

• H04R2201/003

  Mems transducers or their use · CPC title

• B81B2203/0127

  Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function · CPC title

• B81B2201/0257

  Microphones or microspeakers · CPC title

• B81B3/0072

  For controlling internal stress or strain in moving or flexible elements, e.g. stress compensating layers · CPC title