Mems microphone and package with integrated passive acoustic filter, extended soundport

Patent metadata

Field	Value
Publication number	US-2022369025-A1
Application number	US-202217658546-A
Country	US
Kind code	A1
Filing date	Apr 8, 2022
Priority date	May 11, 2021
Publication date	Nov 17, 2022
Grant date	—

Abstract

A MEMS device includes a package for providing an inner volume, a MEMS microphone arranged in the inner volume, a sound port through the package to the inner volume, and a passive acoustic attenuation filter acoustically coupled to the sound port.

First claim

What is claimed is:

1 . A MEMS device comprising:
a package for providing an inner volume; a MEMS microphone arranged in the inner volume; a sound port through the package to the inner volume; and a passive acoustic attenuation filter acoustically coupled to the sound port.

2 . The MEMS device according to claim 1 , wherein the passive acoustic attenuation filter comprises a tube element or an extension cavity, which branches off from the sound port.

3 . The MEMS device according to claim 2 , wherein the tube element has a tube length to provide an attenuation center frequency of the passive acoustic attenuation filter which corresponds to a frequency or frequency range of an acoustic resonance in the inner volume.

4 . The MEMS device according to claim 2 , wherein the passive acoustic attenuation filter is a passive acoustic notch filter acoustically coupled to the sound port, and wherein the tube element has a tube length to provide a notch center frequency of the passive acoustic notch filter which corresponds to a frequency or frequency range of a Helmholtz resonance or a back-cavity resonance in the inner volume.

5 . The MEMS device according to claim 2 , wherein the tube element comprises a bypass tube having a tube inlet and a tube outlet, which are acoustically coupled to the sound port, wherein the tube inlet is arranged in the sound port acoustically upstream to the tube outlet.

6 . The MEMS device according to claim 2 , wherein the tube element comprises a λ/4 tube extension having a tube inlet, which is acoustically coupled to the sound port.

7 . The MEMS device according to claim 1 , wherein the passive acoustic attenuation filter comprises a plurality of parallel tube elements which branch off from the sound port.

8 . The MEMS device according to claim 7 , wherein the plurality of parallel tube elements have the same dimensions for providing the same attenuation center frequency.

9 . The MEMS device according to claim 7 , wherein a subset of the plurality of parallel tube elements has a different dimension with respect to the remaining tube elements for providing a different attenuation center frequency with respect to the attenuation center frequency of the remaining tube elements.

10 . The MEMS device according to claim 2 , wherein the package comprises a substrate structure and a lid structure, wherein the sound port extends through the substrate structure, and wherein the passive acoustic attenuation filter is part of the substrate structure.

11 . The MEMS device according to claim 10 , wherein the tube element is integrated in the substrate structure, is integrated in different layers of the substrate structure or is attached to the substrate structure.

12 . The MEMS device according to claim 2 , wherein the package comprises a substrate structure and a lid structure, wherein the sound port extends through the lid structure, and wherein the passive acoustic attenuation filter is part of the lid structure.

13 . The MEMS device according to claim 12 , wherein the tube element is integrated in the lid structure, is integrated in different layers of the lid structure or is attached to the lid structure.

14 . The MEMS device according to claim 2 , wherein the passive acoustic attenuation filter is part of a filter device attached to the package at the sound port, wherein the filter device comprises partially the sound port and the tube element.

15 . The MEMS device according to claim 2 , wherein the tube element of the passive acoustic attenuation filter comprises a spiral tube extending around the sound port.

16 . The MEMS device according to claim 2 , wherein the tube element of the passive acoustic attenuation filter is filled with a medium having a different speed of sound than the medium of the environmental atmosphere.

Assignees

• Infineon Technologies Ag

Inventors

• Neumaier Daniel
• De Milleri Niccoló

Classifications

• B81B3/0059

  Constitution or structural means for controlling the movement not provided for in groups B81B3/0037 - B81B3/0056 · CPC title

• H04R19/005 Primary

  using semiconductor materials · CPC title

• H04R2201/003

  Mems transducers or their use · CPC title

• H04R1/222

  for microphones (H04R1/24, H04R1/26 take precedence) · 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