Co-located microelectromechanical system microphone and sensor with minimal acoustic coupling

Patent metadata

Field	Value
Publication number	US-12273680-B2
Application number	US-202218045888-A
Country	US
Kind code	B2
Filing date	Oct 12, 2022
Priority date	Mar 15, 2022
Publication date	Apr 8, 2025
Grant date	Apr 8, 2025

Abstract

An electronic device package comprises a primary microphone having a frequency response having a first resonance frequency, and a reference microphone having a frequency response including a second resonance frequency, the primary microphone and the reference microphone configured to substantially simultaneously receive a same acoustic signal to produce a transduced signal of the primary microphone and a transduced signal of the reference microphone, the second resonance frequency of the reference microphone being different than the first resonance frequency of the primary microphone, the package having dimensions that cause the primary microphone and reference microphone to be acoustically isolated from one another at the resonance frequency of the primary microphone, there being less than 3 dB of acoustic coupling between the primary microphone and reference microphone at the first resonance frequency.

First claim

What is claimed is:

1. An electronic device package comprising:
a primary microphone having a frequency response having a first resonance frequency; and
a reference microphone having a frequency response including a second resonance frequency, the primary microphone and the reference microphone configured to substantially simultaneously receive a same acoustic signal to produce a transduced signal of the primary microphone and a transduced signal of the reference microphone, the second resonance frequency of the reference microphone being different than the first resonance frequency of the primary microphone, the package having dimensions that cause the primary microphone and reference microphone to be acoustically isolated from one another at the first resonance frequency of the primary microphone, there being less than 3 dB of acoustic coupling between the primary microphone and reference microphone at the first resonance frequency.

2. The package of claim 1 wherein the primary microphone and reference microphone share an enclosure having a volume, the package having an acoustic port with a diameter and a depth, the volume, depth, and diameter optimized to provide the less than 3 dB of acoustic coupling between the primary microphone and reference microphone at the first resonance frequency.

3. The package of claim 1 wherein the primary microphone and reference microphone share an enclosure having a first volume, the package including an acoustic port with a diameter and a depth, and a front cavity having a second volume, the second volume, first resonance frequency, and second resonance frequency optimized to provide the less than 3 dB of acoustic coupling between the primary microphone and reference microphone at the first resonance frequency.

4. The package of claim 1 wherein each of the primary microphone and the reference microphone is a micro-electromechanical system (MEMS) microphone.

5. The package of claim 1 wherein the first resonance frequency of the primary microphone is below 20 kHz.

6. The package of claim 5 wherein the second resonance frequency of the reference microphone is above 20 kHz.

7. The package of claim 1 configured as a system-in-package module.

8. The package of claim 1 configured as a system-on-chip module.

9. The package of claim 1 wherein the primary microphone and reference microphone are formed on a same die.

10. The package of claim 1 wherein the primary microphone and reference microphone share a same acoustic port and a same front cavity.

11. The package of claim 10 wherein the primary microphone and reference microphone share a same back cavity.

12. The package of claim 1 wherein the primary microphone and reference microphone have different respective acoustic ports but share a same back cavity.

13. The package of claim 1 wherein the primary microphone and reference microphone are disposed in a same plane and separated laterally from one another.

14. The package of claim 1 wherein the primary microphone and reference microphone are formed on a same substrate by a same manufacturing process.

15. The package of claim 1 further comprising a plurality of cascaded primary microphones.

16. The package of claim 15 further comprising a plurality of cascaded reference microphones.

17. The package of claim 16 wherein the plurality of cascaded primary microphones and the plurality of cascaded reference microphones share a same acoustic port and a same front cavity.

18. The package of claim 17 wherein the plurality of cascaded primary microphones and the plurality of cascaded reference microphones share a same back cavity.

19. The package of claim 16 wherein the plurality of cascaded primary microphones and the plurality of cascaded reference microphones have different respective acoustic ports but share a same back cavity.

20. The package of claim 16 wherein the plurality of cascaded primary microphones and the plurality of cascaded reference microphones are disposed in an arrangement having at least two axes of symmetry.

21. The package of claim 16 wherein the plurality of cascaded primary microphones and the plurality of cascaded reference microphones are disposed in a concentric arrangement.

22. The package of claim 16 wherein the plurality of cascaded primary microphones and the plurality of cascaded reference microphones are circumferentially arranged.

23. The package of claim 16 wherein the plurality of cascaded primary microphones are shaped differently from the plurality of cascaded reference microphones.

24. A method of fabricating a package including a primary microphone and a reference sensor, the method comprising:
defining a first resonance frequency of the primary microphone and a second resonance frequency of the reference sensor;
defining a volume of a front cavity of the package;
defining a decoupling criterion;
initializing a thickness and a diameter of an acoustic port of the package;
initializing a volume of a back cavity of the package;
determining an amount of acoustic coupling between the primary microphone and the reference sensor at the first resonance frequency; and
responsive to the acoustic coupling being greater than the decoupling criteria, adjusting one or more of the thickness of the acoustic port, diameter of the acoustic port, or the volume of the back cavity and iterating the adjusting until the acoustic coupling is less than the decoupling criteria.

25. A method of fabricating a package including a primary microphone and a reference sensor, the method comprising:
defining a thickness and a diameter of an acoustic port of the package;
defining a volume of a back cavity of the package;
defining a decoupling criterion;
initializing a first resonance frequency of the primary microphone and a second resonance frequency of the reference sensor;
initializing a volume of a front cavity of the package;
determining an amount of acoustic coupling between the primary microphone and the reference sensor at the first resonance frequency; and
responsive to the acoustic coupling being greater than the decoupling criteria, adjusting one or more of the first resonance frequency, the second resonance frequency, or the volume of the front cavity and iterating the adjusting until the acoustic coupling is less than the decoupling criteria.

Assignees

• Skyworks Solutions Inc

Inventors

• Campanella-Pineda Humberto
• Wurtz Michael Jon
• Qian You
• Chen Guofeng
• Kumar Rakesh

Classifications

• H04R1/04

  Structural association of microphone with electric circuitry therefor (in electric hearing aids H04R25/00) · CPC title

• H04R31/006

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

• H04R19/04

  Microphones (H04R19/01 takes precedence) · CPC title

• H04R2201/003

  Mems transducers or their use · CPC title

• G01H3/12 Primary

  by electric means (G01H3/14 takes precedence) · CPC title