Micromechanical sound transducer system and corresponding manufacturing method

Patent metadata

Field	Value
Publication number	US-10547951-B2
Application number	US-201815861787-A
Country	US
Kind code	B2
Filing date	Jan 4, 2018
Priority date	Jan 5, 2017
Publication date	Jan 28, 2020
Grant date	Jan 28, 2020

Abstract

A micromechanical sound transducer system includes a substrate that includes (a) a cavity with a cavity edge area, (b) a front side, and (c) a rear side; a piezoelectric vibrating beam that is elastically suspended on the front side and that extends across the cavity; and, for the piezoelectric vibrating beam, a respective deflection limiting device that is on a front edge area of the respective vibrating beam and that is configured to limit a deflection of the respective vibrating beam to a limiting deflection by causing the respective front edge area of the respective vibrating beam to interact with the cavity edge area or an opposing front edge area of another vibrating beam.

First claim

What is claimed is:

1. A micromechanical sound transducer system, including:
a substrate having a cavity with a cavity edge area, a front side, and a rear side;
at least two front piezoelectric vibrating beams, each of which is elastically suspended on the front side and which extends across the cavity towards the rear side;
at least two rear piezoelectric vibrating beams, each of which is elastically suspended on the rear side and which extends across the cavity towards a corresponding one of the front piezoelectric vibrating beams of the front side, so that there at least two pairs of front and rear piezoelectric vibrating beams; and
a respective deflection limiting device, connecting each of the at least two pairs of front and rear piezoelectric vibrating beams, which is on a front edge area of a respective one of the vibrating beams and which is configured to limit a deflection of the respective vibrating beam to a limiting deflection by causing the respective front edge area of the respective vibrating beam to interact with an opposing front edge area of the corresponding one of the vibrating beams, which forms a corresponding one of the pairs.

2. The micromechanical sound transducer of claim 1 , wherein the front and rear piezoelectric vibrating beams includes a plurality of piezoelectric vibrating beams, and the deflection limiting device connects to each other opposing front edge areas of a respective pair of the vibrating beams to thereby cause the interaction.

3. The micromechanical sound transducer system of claim 2 , wherein the deflection limiting device is a hook-like or comb-like integral molding configured to cause the opposing front edge areas to stop at a maximum deflection and thereby cause the interaction.

4. The micromechanical sound transducer system of claim 1 , wherein the deflection limiting device is a respective elastic strip device that mechanically connects to the cavity edge area of the respective front edge area of the respective vibrating beam on which the deflection limiting device is positioned to cause the interaction.

5. The micromechanical sound transducer system of claim 4 , wherein the respective elastic strip device is a non-linear spring device.

6. The micromechanical sound transducer system of claim 4 , wherein the respective elastic strip device is formed of at least one of a polymer, an AIN, and a metal.

7. The micromechanical sound transducer system of claim 3 , wherein, in a non-deflected state of the front and rear piezoelectric vibrating beams, the deflection limiting device is situated in a plane of the vibrating beams.

8. The micromechanical sound transducer system of claim 2 , wherein the deflection limiting device is a hook-like integral molding or a comb-like integral molding.

9. A method for manufacturing a micromechanical sound transducer system, the method comprising:
providing a substrate having a cavity with a cavity edge area, a front side, and a rear side;
forming at least two front piezoelectric vibrating beams, each of which is elastically suspended on the front side and which extends across the cavity towards the rear side;
forming at least two rear piezoelectric vibrating beams, each of which is elastically suspended on the rear side and which extends across the cavity towards a corresponding one of the front piezoelectric vibrating beams of the front side, so that there at least two pairs of front and rear piezoelectric vibrating beams; and
forming a respective deflection limiting device, connecting each of the at least two pairs of front and rear piezoelectric vibrating beams, which is on a front edge area of a respective one of the vibrating beams and which is configured to limit a deflection of the respective vibrating beam to a limiting deflection by causing the respective front edge area of the respective vibrating beam to interact with an opposing front edge area of the corresponding one of the vibrating beams, which forms a corresponding one of the pairs.

10. The method of claim 9 , wherein the front and rear piezoelectric vibrating beams includes a plurality of piezoelectric vibrating beams, and the deflection limiting device connects to each other opposing front edge areas of a respective pair of the vibrating beams to thereby cause the interaction.

11. The method of claim 10 , wherein the deflection limiting device is a hook-like or comb-like integral molding configured to cause the opposing front edge areas to stop at a maximum deflection and thereby cause the interaction.

12. The method of claim 9 , wherein the deflection limiting device is a respective elastic strip device that mechanically connects to the cavity edge area of the respective front edge area of the respective vibrating beam on which the deflection limiting device is positioned to cause the interaction.

13. The method of claim 12 , wherein the respective elastic strip device is a non-linear spring device.

14. The method of claim 12 , wherein the respective elastic strip device is formed of at least one of a polymer, an AIN, and a metal.

15. The method of claim 11 , wherein, in a non-deflected state of the front and rear piezoelectric vibrating beams, the deflection limiting device is situated in a plane of the vibrating beams.

16. The method of claim 10 , wherein the deflection limiting device is a hook-like integral molding or a comb-like integral molding.

Assignees

• Bosch Gmbh Robert

Inventors

• Mansour Ahmad
• Pantel Daniel
• Purkl Fabian
• Doessel Kerrin
• Buck Thomas
• Northemann Thomas

Classifications

• B81B3/0072

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

• H04R2201/003

  Mems transducers or their use · CPC title

• H04R19/04 Primary

  Microphones (H04R19/01 takes precedence) · CPC title

• H04R31/006

  Interconnection of transducer parts (of diaphragm and outer suspension by moulding H04R31/003) · CPC title

• B81B2201/032

  Bimorph and unimorph actuators, e.g. piezo and thermo · CPC title