CN210958792U

CN210958792U - MEMS microphone and electronic equipment

Info

Publication number: CN210958792U
Application number: CN201921868576.4U
Authority: CN
Inventors: 黄龙燕
Original assignee: Puma SE
Current assignee: Shenzhen 3Nod Digital Technology Co Ltd; Puma SE
Priority date: 2019-10-29
Filing date: 2019-10-29
Publication date: 2020-07-07
Anticipated expiration: 2029-10-29

Abstract

The embodiment of the application provides an MEMS microphone, which comprises a circuit board, a shell, an ASIC chip and an MEMS acoustic sensor; the shell cover is arranged on the circuit board to form an accommodating cavity, the ASIC chip and the MEMS acoustic sensor are arranged in the accommodating cavity, and the ASIC chip is electrically connected with the MEMS acoustic sensor and the circuit board respectively; a conductive pad and a first grounding pad are arranged on one side of the circuit board, which is far away from the shell, and the first grounding pad is arranged at the peripheral edge of the conductive pad; a second grounding pad is further arranged on one side, close to the shell, of the circuit board, and the first grounding pad and the second grounding pad are electrically connected with the shell in sequence; the accommodating cavity is provided with a sound inlet hole communicated with the outside. When the MEMS microphone is attached to an external circuit board, the MEMS microphone can effectively shield radio frequency signals and electromagnetic wave interference conductive bonding pads; and the first grounding pad is matched with the conductive pad and welded on the external circuit board together, so that the welding firmness and the sealing property can be enhanced.

Description

MEMS microphone and electronic equipment

Technical Field

The present disclosure relates to the field of microphone technologies, and more particularly, to a MEMS microphone and an electronic device.

Background

In recent years, MEMS microphones integrated with MEMS (micro electro mechanical system) processes are widely used in smart mobile devices such as mobile phones, notebooks, smart wearing, earphones, remote controllers, and the like. An MEMS (micro electro mechanical system) microphone is a microphone manufactured based on the MEMS technology, and simply, a capacitor is integrated on a micro silicon wafer, and can be manufactured by a surface mount process, which can withstand a very high reflow temperature, is easily integrated with a CMOS process and other audio circuits, and has the characteristics of high signal-to-noise ratio, low power consumption, and high sensitivity.

However, since various types of smart mobile devices generally have radio frequency signal transmitting and receiving functions and electromagnetic fields, the existing MEMS microphone has poor radio frequency and electromagnetic interference resistance in back-end applications.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the embodiments of the present application is to provide an MEMS microphone and an electronic device with enhanced radio frequency and electromagnetic interference resistance.

In order to solve the above technical problem, an embodiment of the present application provides an MEMS microphone, which adopts the following technical solutions:

an MEMS microphone comprises a circuit board, a shell, an ASIC chip and an MEMS acoustic sensor;

the shell cover is arranged on the circuit board to form an accommodating cavity, the ASIC chip and the MEMS acoustic sensor are both arranged in the accommodating cavity, and the ASIC chip is electrically connected with the MEMS acoustic sensor and the circuit board respectively;

a conductive pad and a first grounding pad are arranged on one side of the circuit board, which is far away from the shell, and the first grounding pad is arranged at the peripheral edge of the conductive pad;

a second grounding pad is further arranged on one side, close to the shell, of the circuit board, and the first grounding pad and the second grounding pad are electrically connected with the shell in sequence;

the accommodating cavity is provided with a sound inlet hole communicated with the outside.

As a further improvement of the above technical solution, the first ground pad and the second ground pad are connected by a metallization hole.

As a further improvement of the above technical solution, the first ground pad has a hollow ring shape.

As a further improvement of the above technical means, the second ground pad has a hollow ring shape, is provided corresponding to the housing, and is connected thereto by soldering.

As a further improvement of the above technical solution, the sound inlet hole is disposed on the circuit board.

As a further improvement of the above technical solution, the sound inlet hole is provided in the housing.

As a further improvement of the above technical solution, the ASIC chip is electrically connected to the MEMS acoustic sensor by a first gold wire.

As a further improvement of the above technical solution, the ASIC chip is electrically connected to the circuit board by a second gold wire.

As a further improvement of the above technical solution, the housing is made of a metal material having weldability.

In order to solve the above technical problem, an embodiment of the present application further provides an electronic device, which adopts the following technical solutions:

an electronic device comprising a MEMS microphone as described above.

Compared with the prior art, the embodiment of the application mainly has the following beneficial effects:

the embodiment of the application provides an MEMS microphone, wherein a first grounding pad and a second grounding pad are arranged on a circuit board, the first grounding pad surrounds a conductive pad, the second grounding pad is electrically connected with a shell in sequence, when the MEMS microphone is attached to an external circuit board, the first grounding pad, the second grounding pad and the shell form a grounding shielding layer, so that radio frequency signals and electromagnetic waves can be effectively shielded from interfering the conductive pad from a gap between the circuit board and the external circuit board, the external radio frequency signals and electromagnetic light are prevented from interfering input and output signals, and therefore pickup acoustic signals of the MEMS microphone are improved; in addition, the first grounding pad and the conductive pad are jointly welded on the external circuit board, so that the welding area is increased, and the welding firmness and the sealing performance can be further enhanced.

Drawings

In order to illustrate the present application or prior art more clearly, a brief description of the drawings needed for the description of the embodiments or prior art will be given below, it being clear that the drawings in the following description are some embodiments of the present application and that other drawings can be derived from them by a person skilled in the art without inventive effort.

Fig. 1 is a schematic longitudinal sectional structure diagram of a MEMS microphone according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a bottom surface of a MEMS microphone according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a side of a circuit board of a MEMS microphone near a second ground pad according to an embodiment of the present invention;

fig. 4 is a schematic view of an installation of a MEMS microphone according to an embodiment of the present invention;

fig. 5 is a schematic longitudinal sectional structure view of a MEMS microphone according to another embodiment of the present invention;

fig. 6 is a schematic view of the installation of a MEMS microphone in the prior art.

Reference numerals:

100. a circuit board; 110. a conductive pad; 120. a first ground pad; 130. a second ground pad; 200. a housing; 300. a MEMS acoustic sensor; 400. an ASIC chip; 500. a sound inlet hole; 600. a first gold wire; 610. a second gold wire; 700. an external circuit board; 800. a gap.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the description and claims of this application or in the above-described drawings are used for distinguishing between different objects and not for describing a particular order.

In this context, it will be understood by those skilled in the art that terms indicating orientation or positional relationship herein are based on the orientation or positional relationship shown in the drawings and are for convenience in describing the present application and for simplicity in description, but do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be considered limiting of the present application.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

Example one

Referring to fig. 1, the MEMS microphone includes a Circuit board 100, a housing 200, an ASIC (Application Specific Integrated Circuit, ASIC for short) chip 400, and a MEMS (micro electro mechanical Systems, MEMS for short) acoustic sensor 300;

the housing 200 is covered on the circuit board 100 to form an accommodating cavity, the ASIC chip 400 and the MEMS acoustic sensor 300 are both disposed in the accommodating cavity, and the housing 200 protects the ASIC chip 400 and the MEMS acoustic sensor 300 disposed in the accommodating cavity;

the ASIC chip 400 is electrically connected to the MEMS acoustic sensor 300 and the circuit board 100, respectively;

a first grounding pad 120 and a conductive pad 110 for inputting and outputting signals of the MEMS microphone are disposed on one side of the circuit board 100 away from the housing 200, and the first grounding pad 120 is disposed at the peripheral edge of the conductive pad 110;

a second grounding pad 130 is further disposed on one side of the circuit board 100 close to the housing 200, and the first grounding pad 120 and the second grounding pad 130 are electrically connected to the housing 200 in sequence;

the accommodating cavity is provided with a sound inlet hole 500 communicated with the outside, and the arrangement of the sound inlet hole 500 is convenient for sound to be transmitted into the MEMS acoustic sensor 300 in the accommodating cavity.

As described above, referring to fig. 4, when the MEMS microphone is connected to the external circuit board 700, the MEMS microphone is connected to the external circuit board 700 through the conductive pad 110 and the first ground pad 120, and the specific connection manner may be that the conductive pad 110 and the first ground pad 120 are soldered to the external circuit board 700 through an SMT mounting process, so as to achieve the purpose of electrically connecting the MEMS microphone to the external circuit board 700.

It can be understood that, by providing the first ground pad 120 and the second ground pad 130 on the circuit board 100, wherein the first ground pad 120 encloses the conductive pad 110, and the first ground pad 120 and the second ground pad 130 are electrically connected to the housing 200 in sequence, when the MEMS microphone is attached to the external circuit board 700, the first ground pad 120, the second ground pad 130 and the housing 200 form a ground shielding layer, which can effectively shield the external radio frequency signal and the electromagnetic wave from interfering with the conductive pad 110 at the gap 800 between the circuit board 100 and the external circuit board 700, and prevent the external radio frequency signal and the electromagnetic wave from interfering with the input and output signals, thereby improving the sound pickup signal of the MEMS microphone; in addition, the first ground pad 120 is soldered to the external circuit board 700 in cooperation with the conductive pad 110, so that the soldering area is increased, and the soldering reliability and the sealing performance can be further enhanced.

Specifically, the external circuit board 700 may be a PCB such as a flexible FPC board, a flexible-rigid board, and a rigid board.

Alternatively, the number of the conductive pads 110 may be 1, 2, 3, etc., and is not particularly limited herein.

Optionally, referring to fig. 2, the shape of the first ground pad 120 is a hollow ring, the conductive pad 110 is located in the hollow of the first ground pad 120, so as to surround the conductive pad 110 in the ring, the shape of the first ground pad 120 is designed as a circular ring, a square ring, or other irregular ring, for example, and the shape of the first ground pad 120 is not particularly limited herein.

Optionally, the first ground pad 120 and the second ground pad 130 are electrically connected through a metalized hole.

Alternatively, the shape of the wiring board 100 may be square, circular, polygonal, etc., and is not particularly limited herein.

In order to form a sealed connection state in the receiving cavity except for the sound inlet 500, referring to fig. 3, the second grounding pad 130 is shaped like a hollow ring and is disposed corresponding to the housing 200, and the housing 200 is hermetically connected to the second grounding pad 130, so that the housing 200 covers the circuit board 100 to form a sealed connection state.

In the present embodiment, the housing 200 is soldered to the second ground pad 130 by solder paste or conductive silver paste and an electrical connection is achieved.

Optionally, the housing 200 is made of a metal material with solderability, so that the housing 200 can be soldered to the second ground pad 130.

Optionally, the MEMS acoustic sensor 300 and the ASIC chip 400 are disposed on the circuit board 100, and the specific connection manner may be through adhesive bonding.

Optionally, the MEMS acoustic sensor 300 and the ASIC chip 400 may be electrically connected in various manners, for example, the MEMS acoustic sensor 300 and the ASIC chip 400 may be electrically connected by a wire bonding connection, and the wire may be a conductive metal wire.

Preferably, the MEMS acoustic sensor 300 is electrically connected to the ASIC chip 400 through a first gold wire 600.

Optionally, the ASIC chip 400 and the circuit board 100 may be electrically connected in various ways, for example, the ASIC chip 400 and the circuit board 100 may be electrically connected by a wire bonding connection method through a wire, and the wire may be a conductive metal wire.

Preferably, the ASIC chip 400 is electrically connected to the circuit board 100 through a second gold wire 610.

In this embodiment, referring to fig. 1, the sound inlet hole 500 is disposed on the circuit board 100, and the sound is directly transmitted to the MEMS acoustic sensor 300 through the sound inlet hole 500.

Optionally, the sound inlet hole 500 faces the MEMS acoustic sensor 300.

Further, the sound inlet hole 500 is disposed on the circuit board 100 at a position opposite to the MEMS acoustic sensor 300.

In another embodiment, referring to fig. 5, the sound inlet hole 500 is disposed on the housing 200, and the sound propagates to the MEMS acoustic sensor 300 through the internal sound cavity.

Optionally, the sound inlet hole 500 faces the MEMS acoustic sensor 300 or the ASIC chip 400.

Compared with the prior art, the embodiment of the utility model provides a MEMS microphone has following progress:

referring to fig. 6, in the prior art, since the circuit board 100 of the MEMS microphone is directly soldered to the external circuit board 700 through the conductive pad 110 when being mounted on the external circuit board 700, there is a gap 800 with a certain height after being mounted, and radio frequency signals and electromagnetic waves are easily radiated from the gap 800 to interfere with the conductive pad 110 of the MEMS microphone, so as to interfere with input and output signals of the MEMS microphone, thereby reducing the quality of sound signals picked up by the MEMS microphone.

In the present application, when the MEMS microphone is attached to the external circuit board 700, the first ground pad 120 surrounds the conductive pad 110 in a ring, and the first ground pad 120, the second ground pad 130 and the housing 200 form a ground shielding layer, so that external radio frequency signals and electromagnetic waves can be effectively shielded from interfering with the conductive pad 110 from the gap 800, and the external radio frequency signals and electromagnetic waves can be prevented from interfering with input and output signals, so that the sound pickup signals of the MEMS microphone can be improved; in addition, the first ground pad 120 is soldered to the external circuit board 700 in cooperation with the conductive pad 110, so that the soldering area is increased, and the soldering reliability and the sealing performance can be further enhanced.

The MEMS microphone provided by the utility model has the characteristics of simple structure, small, with low costs, easily mass production manufacturing.

Example two

The present embodiment provides an electronic device comprising the MEMS microphone according to embodiment 1.

It is understood that the electronic devices include smart mobile electronic devices such as mobile phones, notebooks, smart wearing, headsets, remote controls, and the like.

It is to be understood that the above-described embodiments are merely illustrative of some, but not restrictive, of the broad invention, and that the appended drawings illustrate preferred embodiments of the invention and do not limit the scope of the invention. This application is capable of embodiments in many different forms and is provided for the purpose of enabling a thorough understanding of the disclosure of the application. Although the present application has been described in detail with reference to the foregoing embodiments, it will be apparent to one skilled in the art that the present application may be practiced without modification or with equivalents of some of the features described in the foregoing embodiments. All equivalent structures made by using the contents of the specification and the drawings of the present application are directly or indirectly applied to other related technical fields and are within the protection scope of the present application.

Claims

1. An MEMS microphone is characterized by comprising a circuit board, a shell, an ASIC chip and an MEMS acoustic sensor;

2. The MEMS microphone of claim 1, wherein the first ground pad and the second ground pad are connected by a metalized via.

3. The MEMS microphone of claim 1, wherein the first ground pad is shaped as a hollow ring.

4. The MEMS microphone of claim 1, wherein the second ground pad has a hollow ring shape, is provided corresponding to the housing, and is connected by soldering.

5. The MEMS microphone of claim 1, wherein the sound inlet hole is disposed on the circuit board.

6. The MEMS microphone of claim 1, wherein the sound inlet hole is disposed on the housing.

7. The MEMS microphone of claim 1, wherein the ASIC chip is electrically connected to the MEMS acoustic sensor by a first gold wire.

8. The MEMS microphone of claim 1, wherein the ASIC chip is electrically connected to the wiring board by a second gold wire.

9. The MEMS microphone of claim 1, wherein the housing is made of a metallic material having solderability.

10. An electronic device, characterized in that the electronic device comprises a MEMS microphone according to any of claims 1-9.