Microelectromechanical transducer

Patent metadata

Field	Value
Publication number	US-10626007-B2
Application number	US-201816031722-A
Country	US
Kind code	B2
Filing date	Jul 10, 2018
Priority date	Jul 14, 2017
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

In accordance with an embodiment, a microelectromechanical transducer includes a displaceable membrane having an undulated section comprising at least one undulation trough and at least one undulation peak and a plurality of piezoelectric unit cells. At least one piezoelectric unit cell is provided in each case in at least one undulation trough and at least one undulation peak, where each piezoelectric unit cell has a piezoelectric layer and at least one electrode in electrical contact with the piezoelectric layer. The membrane may be formed as a planar component having a substantially larger extent in a first and a second spatial direction, which are orthogonal to one another, than in a third spatial direction, which is orthogonal to the first and the second spatial direction and defines an axial direction of the membrane.

First claim

What is claimed is:

1. A microelectromechanical transducer comprising:
a displaceable membrane having an undulated section comprising at least one undulation trough and at least one undulation peak;
a plurality of piezoelectric unit cells, wherein at least one piezoelectric unit cell of the plurality of piezoelectric unit cells is provided in each case in at least one undulation trough and at least one undulation peak, wherein each piezoelectric unit cell of the plurality of piezoelectric unit cells has a piezoelectric layer and at least one electrode in electrical contact with the piezoelectric layer,
wherein the membrane is formed as a planar component, which has a substantially larger extent in a first and a second spatial direction, which are orthogonal to one another, than in a third spatial direction, which is orthogonal to the first and the second spatial direction and defines an axial direction of the membrane,
wherein the at least one undulation peak and the at least one undulation trough are provided consecutively in a radial direction of the membrane; or
wherein the at least one undulation peak and the at least one undulation trough are provided consecutively in a circumferential direction of the membrane.

2. The microelectromechanical transducer as claimed in claim 1 ,
wherein the undulated section has a plurality of undulation peaks or/and a plurality of undulation troughs.

3. The microelectromechanical transducer as claimed in claim 2 ,
wherein the at least one piezoelectric unit cell has an electrode on just one side of its piezoelectric layer, wherein the electrodes of different piezoelectric unit cells are formed separately from one another; and
wherein a piezoelectric unit cell of the plurality of piezoelectric unit cells is provided in each case at the plurality of undulation peaks, wherein the piezoelectric unit cells provided at the plurality of undulation peaks have in each case electrodes on the same side of their piezoelectric layers, which electrodes are formed separately from one another and are electrically connected in parallel with one another or/and wherein a piezoelectric unit cell of the plurality of piezoelectric unit cells is provided in each case in the plurality of undulation troughs, wherein a plurality of or all of the unit cells provided in the plurality of undulation troughs have in each case electrodes on the same side of their piezoelectric layers, which electrodes are formed separately from one another and are electrically connected in parallel with one another.

4. The microelectromechanical transducer as claimed in claim 3 , further comprising a plurality of the electrodes connected electrically in parallel and provided at the undulation peaks and a plurality of the electrodes connected electrically in parallel and provided in the undulation troughs, wherein the electrodes provided at the undulation peaks and connected electrically in parallel with one another are electrically connected in series with the electrodes provided in the undulation troughs and connected electrically in parallel with one another.

5. The microelectromechanical transducer as claimed in claim 4 , wherein the plurality of the undulation peaks at which the plurality of the electrodes electrically connected in parallel with one another are provided are arranged consecutively in the radial direction of the membrane and wherein the plurality of the undulation troughs in which the plurality of the electrodes electrically connected in parallel with one another are provided are arranged consecutively in the radial direction of the membrane, wherein the electrodes connected in parallel and provided at the plurality of the undulation peaks and the electrodes connected in parallel and provided in the plurality of the undulation troughs, which electrodes are electrically connected in series with one another.

6. The microelectromechanical transducer as claimed in claim 5 , wherein a connecting electrode that extends in the radial direction is provided in the circumferential direction between the electrodes provided at the plurality of the undulation peaks and connected in parallel and the electrodes provided in the plurality of the undulation troughs and connected in parallel, by means of which connecting electrode the electrodes provided at the plurality of the undulation peaks and connected in parallel are electrically connected in series with the electrodes provided in the plurality of the undulation troughs and connected in parallel.

7. The microelectromechanical transducer as claimed in claim 2 ,
wherein the at least one piezoelectric unit cell has an electrode on just one side of its piezoelectric layer, wherein the electrodes of different piezoelectric unit cells are formed separately from one another, and
wherein the microelectromechanical transducer comprises the plurality of undulation peaks and the plurality of undulation troughs, which are provided consecutively in the radial direction of the membrane in alternating fashion.

8. The microelectromechanical transducer as claimed in claim 7 ,
wherein the plurality of undulation troughs or/and the plurality of undulation peaks have a substantially circular or circular-segment-shaped design.

9. The microelectromechanical transducer as claimed in claim 2
wherein the at least one piezoelectric unit cell has an electrode on just one side of its piezoelectric layer, wherein the electrodes of different piezoelectric unit cells are formed separately from one another, and
the microelectromechanical transducer further comprises the plurality of undulation peaks and the plurality of undulation troughs, which have in each case a substantially radial main extent and are provided consecutively in the circumferential direction of the membrane in alternating fashion.

10. The microelectromechanical transducer as claimed in claim 1 ,
wherein the at least one piezoelectric unit cell has an electrode on just one side of its piezoelectric layer, wherein the electrodes of different piezoelectric unit cells are formed separately from one another.

11. The microelectromechanical transducer as claimed in claim 1 , wherein the at least one piezoelectric unit cell has electrodes on mutually opposite sides of its piezoelectric layer.

12. The microelectromechanical transducer as claimed in claim ii,
wherein the plurality of piezoelectric unit cells have electrodes on mutually opposite sides of their piezoelectric layers, and the electrodes of the plurality of piezoelectric unit cells on a first side of the piezoelectric layers are formed separately from one another and the electrodes of the plurality of piezoelectric unit cells on a second side of the piezoelectric layers, which is opposite the first side, are formed integrally with one another.

13. The microelectromechanical transducer as claimed in claim 12 ,
wherein the plurality of the undulation peaks at which the plurality of the electrodes electrically connected in parallel with one another are provided are arranged consecutively in the radial direction of the membrane and wherein the plurality of the undulation troughs in which the plurality of the electrodes electrically connected in parallel with one another are provided are arranged consecutively in the radial direction of the membrane, wherein the electrodes connected in parallel and provided at the plurality of the undulation peaks and the electrodes connected in parallel and provided in the plurality of the undulation troughs, which electrodes are electrically connected in series with one another,
wherein the piezoelectric unit cells corresponding to the plurality of the electrodes provided at the und

Assignees

• Infineon Technologies Ag

Inventors

• Bretthauer Christian
• Dehe Alfons
• Sigl Alfred

Classifications

• B81B2201/0257

  Microphones or microspeakers · CPC title

• H04R17/02 Primary

  Microphones · CPC title

• B81B7/02

  containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS] (B81B7/04 takes precedence) · CPC title

• B81B2201/0264

  Pressure sensors · CPC title

• H04R31/003

  for diaphragms or their outer suspension · CPC title