CN-122027929-A - Microelectromechanical system microphone with increased back volume

Abstract

The application relates to a microelectromechanical system microphone with an increased back volume. A microelectromechanical system (MEMS) microphone may include a housing, an Integrated Circuit (IC), and a MEMS transducer. The housing may include a cover mounted on a base having a first Printed Circuit Board (PCB) facing a second PCB. The first recess may be located in the base and at least partially defined by a hole through the first PCB. The second recess may be located in the base and at least partially defined by a cavity in the first PCB. The internal electrical interface may be located on a side of the first PCB in the housing facing the second PCB. The MEMS transducer may be electrically connected to the IC and include a diaphragm dividing an interior of the housing into a front volume and a back volume, wherein the first recess and the second recess form a portion of the back volume.

Inventors

• MONTI CHRISTOPHER
• J Sizehe

Assignees

• 美商楼氏电子有限公司

Dates

Publication Date

20260512

Application Date

20251110

Priority Date

20241112

Claims (19)

1. 1. A microelectromechanical system microphone, the microelectromechanical system microphone comprising: a housing including a cover mounted on a base, the base including a first printed circuit board facing a second printed circuit board, the cover being located on a side of the first printed circuit board facing away from the second printed circuit board; A first recess in the base and at least partially defined by a hole through the first printed circuit board; A second recess in the base and at least partially defined by a cavity in the first printed circuit board; An internal electrical interface located in the housing and between the first printed circuit board and the second printed circuit board; An external electrical interface on a side of the base facing an exterior of the housing, the external electrical interface electrically connected to the internal electrical interface; An integrated circuit located in the housing and electrically connected to the internal electrical interface, and A mems transducer located in the housing and mounted on an inside of the cover over the sound port of the cover, the mems transducer electrically connected to the integrated circuit, the mems transducer comprising a diaphragm dividing an interior of the housing into a front volume and a back volume, the front volume being located between the diaphragm and the sound port and the back volume being located between the diaphragm and the base, wherein the first recess and the second recess form part of the back volume.
2. 2. The microelectromechanical system microphone of claim 1, wherein the integrated circuit is electrically connected to the internal electrical interface by an electrical conductor that extends through the aperture of the first recess into a channel between the first recess and the internal electrical interface.
3. 3. The microelectromechanical system microphone of claim 1, wherein the first recess comprises a cavity in the second printed circuit board that overlaps the internal electrical interface, wherein the integrated circuit is electrically connected to the internal electrical interface by an electrical conductor that extends through the aperture of the first recess into the cavity of the first recess.
4. 4. The mems microphone of claim 3, wherein the internal electrical interface is located on a side of the first printed circuit board facing the second printed circuit board.
5. 5. The mems microphone of claim 1, wherein the second recess comprises a hole through the first printed circuit board.
6. 6. The mems microphone of claim 5, wherein the second recess further comprises a cavity in the second printed circuit board.
7. 7. The mems microphone of claim 1, wherein the integrated circuit is mounted on the inner side of the cover.
8. 8. The microelectromechanical system microphone of claim 1, wherein the internal electrical interface is located between the first recess and the second recess.
9. 9. The mems microphone of claim 8, wherein the internal electrical interface is located on a portion of the first printed circuit board separating the first recess and the second recess.
10. 10. A microelectromechanical system microphone, the microelectromechanical system microphone comprising: a housing including a cover mounted on a base, the base including a first printed circuit board facing a second printed circuit board, the cover being located on a side of the first printed circuit board facing away from the second printed circuit board; a first recess in the base and including a hole through the first printed circuit board and a cavity in the second printed circuit board; A second recess in the base and at least partially defined by a cavity in the first printed circuit board; an internal electrical interface located in the housing and on a side of the first printed circuit board facing the second printed circuit board; An external electrical interface on a side of the base facing an exterior of the housing, the external electrical interface electrically connected to the internal electrical interface; An integrated circuit mounted on an inner side of the cover and electrically connected to the internal electrical interface via conductors extending into the cavity of the first recess through the aperture of the first recess, and A microelectromechanical system transducer located in the housing and mounted over the sound port of the cover on the inside of the cover, the microelectromechanical system transducer electrically connected to the integrated circuit, the microelectromechanical system transducer comprising a diaphragm dividing an interior of the housing into a front volume and a back volume, the front volume being located between the diaphragm and the sound port and the back volume being located between the diaphragm and the base, wherein the first recess and the second recess form part of the back volume.
11. 11. The microelectromechanical system microphone of claim 10, wherein the internal electrical interface is located between the first recess and the second recess.
12. 12. The mems microphone of claim 10, wherein the second recess comprises a hole through the first printed circuit board.
13. 13. The mems microphone of claim 12, wherein the second recess further comprises a cavity in the second printed circuit board.
14. 14. The mems microphone of claim 12, wherein the aperture of the first recess and the aperture of the second recess form a communication aperture through the first printed circuit board.
15. 15. The mems microphone of claim 14, wherein the internal electrical interface is located on a portion of the first printed circuit board protruding through the first printed circuit board into the communication aperture.
16. 16. The mems microphone of claim 15, wherein the second recess further comprises a cavity in the second printed circuit board.
17. 17. A microelectromechanical system microphone, the microelectromechanical system microphone comprising: a housing including a cover mounted on a base, the base including a first printed circuit board facing a second printed circuit board, the cover being located on a side of the first printed circuit board facing away from the second printed circuit board; a first recess in the base and including a hole through the first printed circuit board and a cavity in the second printed circuit board; an internal electrical interface located in the housing and on a side of the first printed circuit board facing the second printed circuit board; An external electrical interface on a side of the base facing an exterior of the housing, the external electrical interface electrically connected to the internal electrical interface; An integrated circuit mounted on an inner side of the cover and electrically connected to the internal electrical interface via conductors extending into the cavity of the first recess through the aperture of the first recess, and A microelectromechanical system transducer located in the housing and mounted over the sound port of the cover on the inside of the cover, the microelectromechanical system transducer electrically connected to the integrated circuit, the microelectromechanical system transducer comprising a diaphragm dividing an interior of the housing into a front volume and a back volume, the front volume being located between the diaphragm and the sound port, and the back volume being located between the diaphragm and the base, wherein the first recess and the second recess form part of the back volume.
18. 18. The mems microphone of claim 17, wherein the internal electrical interface is located on a portion of the first printed circuit board protruding through the first printed circuit board into the aperture.
19. 19. The mems microphone of claim 18, wherein the internal electrical interface is located between the first recess and the second recess.

Description

Microelectromechanical system microphone with increased back volume Technical Field The present disclosure relates generally to microelectromechanical systems (MEMS) microphones, and more particularly to top port MEMS microphones. Background Microelectromechanical System (MEMS) transducers are increasingly used in a variety of applications due to their small size, low cost, and the ability to easily integrate them into host devices and systems. MEMS transducers are commonly used to detect sound in wireless handsets, laptops, smart speakers, wireless headsets, appliances and automobiles, as well as various other consumer and industrial products and machinery. It is desirable to improve the acoustic performance of MEMS microphones. Improvements may be produced by increasing the sensitivity of the MEMS microphone, increasing the signal-to-noise ratio (SNR), and improving the low frequency response of the microphone. Each of these performance characteristics may be improved by increasing the back volume of the MEMS microphone. Unfortunately, the space available for increasing back volume in MEMS microphones is very limited, especially due to the need for smaller and smaller devices. This is especially true for top port MEMS microphones. Accordingly, there is a need for a MEMS microphone with improved acoustic performance, and in particular, a top port MEMS microphone with increased back volume. Disclosure of Invention One aspect of the application relates to a microelectromechanical system microphone comprising a housing comprising a cover mounted on a base, the base comprising a first printed circuit board facing a second printed circuit board, the cover being located on a side of the first printed circuit board facing away from the second printed circuit board, a first recess located in the base and defined at least in part by an aperture through the first printed circuit board, a second recess located in the base and defined at least in part by a cavity in the first printed circuit board, an internal electromechanical interface located in the housing and located between the first printed circuit board and the second printed circuit board, an external electromechanical interface located on a side of the base facing the outside of the housing, the external electromechanical interface being electrically connected to the internal interface, an integrated circuit located in the base and at least in part by an aperture through the first printed circuit board, a membrane and a membrane transducer located between the internal and the integrated circuit and the membrane, wherein the membrane transducer is divided between the internal and the volume, the membrane and the membrane is located between the internal and the membrane, the first recess and the second recess form part of the back volume. The integrated circuit is electrically connected to the internal electrical interface by an electrical conductor that extends through the aperture of the first recess into a channel between the first recess and the internal electrical interface. The first recess includes a cavity in the second printed circuit board that overlaps the internal electrical interface, wherein the integrated circuit is electrically connected to the internal electrical interface by an electrical conductor that extends into the cavity of the first recess through the aperture of the first recess. The internal electrical interface is located on a side of the first printed circuit board facing the second printed circuit board. The second recess includes a hole through the first printed circuit board. The second recess further includes a cavity in the second printed circuit board. The integrated circuit is mounted on the inner side of the cover. The internal electrical interface is located between the first recess and the second recess. The internal electrical interface is located on a portion of the first printed circuit board separating the first recess and the second recess. Another aspect of the application relates to a mems microphone comprising a housing comprising a cover mounted on a base, the base comprising a first printed circuit board facing a second printed circuit board, the cover being located on a side of the first printed circuit board facing away from the second printed circuit board, a first recess in the base and comprising a hole through the first printed circuit board and a cavity in the second printed circuit board, a second recess in the base and at least partially defined by a cavity in the first printed circuit board, an internal electrical interface in the housing and on a side of the first printed circuit board facing the second printed circuit board, an external electrical interface on a side of the base facing the outside of the housing, the external electrical interface being electrically connected to the internal electrical interface, the integrated circuit being located in the housing and the cavity extending between the