CN211089966U

CN211089966U - MEMS microphone and electronic equipment

Info

Publication number: CN211089966U
Application number: CN201921866051.7U
Authority: CN
Inventors: 黄龙燕
Original assignee: Shenzhen 3Nod Digital Technology Co Ltd
Current assignee: Shenzhen 3Nod Digital Technology Co Ltd
Priority date: 2019-10-29
Filing date: 2019-10-29
Publication date: 2020-07-24
Anticipated expiration: 2029-10-29

Abstract

The embodiment of the present application provides a MEMS microphone, including: the circuit board, the shell, the ASIC chip and the 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; the circuit board is provided with a sound inlet hole and a plurality of annular conductive bonding pads, the plurality of conductive bonding pads are all sleeved at the peripheral edge of the sound inlet hole, and the conductive bonding pads are not intersected; the circuit board is provided with a plurality of annular conductive bonding pads to surround the sound inlet hole, so that when the MEMS microphone is welded on the external circuit board through an SMT (surface mount technology), the condition that sound pick-up sound leaks or non-necessary sound signals are picked up due to open-loop welding of tin paste of the MEMS microphone can be remarkably reduced; in addition, the welding firmness can be further enhanced by welding a plurality of conductive welding pads on the external circuit board together.

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 by MEMS (micro electro mechanical systems) technology 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 MEMS technology, namely a capacitor is integrated on a micro silicon wafer, can be manufactured by adopting a surface-mount process, can bear high reflow soldering temperature, is easy to integrate with a CMOS (complementary metal oxide semiconductor) process and other audio circuits, and has the characteristics of high signal-to-noise ratio, low power consumption and high sensitivity.

In order to allow sound to pass into the MEMS acoustic sensor, the MEMS microphone needs to be perforated in the package structure, and the sound hole can be located on the housing (upper sound hole) or near a pad of the circuit board (lower sound hole). The pad arranged beside the sound inlet hole of the MEMS microphone with the sound hole is used for being welded on an external circuit board through an SMT (surface mount technology) process and preventing external sound from entering the sound inlet hole to leak after welding; for example, as shown in fig. 4, the circuit board 100 of the MEMS microphone is generally provided with only a single circular conductive pad 600 and a plurality of square or circular conductive pads 600 at the periphery of the sound inlet 500 for soldering with an external circuit board, so that local solder paste printing anomalies, such as local solder paste missing, little solder, unevenness, etc., are easily generated when the SMT mounting process is performed, and thus the circular conductive pad 600 at the periphery of the sound inlet 500 is soldered open, and the MEMS microphone generates sound leakage or picks up unnecessary sound signals.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the embodiments of the present application is to provide a MEMS microphone capable of reducing sound-pickup sound leakage or picking up unnecessary sound signals.

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

a MEMS microphone, comprising: the circuit board, the shell, the ASIC chip and the 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;

be equipped with into sound hole and a plurality of annular electrically conductive pad on the circuit board, electrically conductive pad is located the circuit board deviates from one side of shell, it is a plurality of electrically conductive pad all overlaps and locates advance sound hole edge all around, and each electrically conductive pad is all not crossing.

As a further improvement of the above technical solution, the shape of the conductive pad is any one of a circular ring shape, a square ring shape and an irregular ring shape.

As a further improvement of the above technical solution, the conductive pads are circular, a plurality of conductive pads are sleeved to form a concentric circle, and the sound inlet hole is located at the center of the concentric circle.

As a further improvement of the above technical solution, the shape of the circuit board is any one of a circle, a square and an irregular shape.

As a further improvement of the above technical solution, the cross-sectional shape of the housing is any one of a circle, a square and an irregular shape.

As a further improvement of the above technical solution, a metalized hole is provided on the conductive pad.

As a further improvement of the above technical solution, the housing is sealed and adhered to the circuit board by solder paste or conductive silver paste to form an electrical connection.

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.

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, which comprises a circuit board, a sound inlet hole, a plurality of annular conductive bonding pads, a plurality of conductive bonding pads and a plurality of conductive bonding pads, wherein the sound inlet hole is surrounded by the plurality of annular conductive bonding pads, when the conductive bonding pads are welded on an external circuit board by an SMT (surface mount technology), the plurality of conductive bonding pads are all welded with the external circuit board and are mutually matched, and when the open loop of the conductive bonding pads is caused by the abnormal printing of local solder paste generated in the SMT process of any conductive bonding pad, the compensation can be carried out by printing normal conductive bonding pads through other solder pastes, so that the condition that sound pickup sound leakage or non-necessary sound signals are picked up due to the open loop welding of the solder paste of the MEMS; in addition, the plurality of conductive pads are welded on the external circuit board together, so that the welding area is increased, and the welding firmness 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 diagram of a longitudinal cross-sectional structure of an MEMS microphone according to the present invention;

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

fig. 3 is a schematic perspective view of a MEMS microphone according to an embodiment of the present invention;

fig. 4 is a bottom view of a MEMS microphone according to the prior art.

Reference numerals:

100. a circuit board; 200. a housing; 300. a MEMS acoustic sensor; 400. an ASIC chip; 500. a sound inlet hole; 600. a conductive pad; 700. a first gold wire; 800. and a second gold wire.

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

be equipped with on the circuit board 100 and advance sound hole 500 and a plurality of annular electrically conductive pad 600 that are used for MEMS microphone signal input/output, electrically conductive pad 600 is located circuit board 100 deviates from one side of shell 200, and is a plurality of electrically conductive pad 600 all overlaps and locates advance sound hole 500 edge all around, and each electrically conductive pad 600 is all criss-cross.

As described above, when the MEMS microphone is connected to the external circuit board, the MEMS microphone is connected to the external circuit board through the conductive pad 600, and the specific connection manner may be that the conductive pad 600 is soldered to the external circuit board by using solder paste through an SMT mounting process, so as to achieve the purpose of electrically connecting the MEMS microphone to the external circuit board.

It will be appreciated that since the single conductive pad 600 surrounds the sound inlet hole 500, local solder paste printing anomalies due to process defects may cause the conductive pad 600 to open loop when the SMT mounting process is performed, thereby causing pickup sound leakage or picking up unwanted acoustic signals. In this embodiment, the plurality of annular conductive pads 600 are arranged on the circuit board 100 to surround the sound inlet 500, when the MEMS microphone is soldered on the external circuit board by the SMT mounting process, the plurality of conductive pads 600 are soldered to the external circuit board, the plurality of conductive pads 600 are matched with each other, and when any conductive pad 600 is opened due to an open loop of the conductive pad 600 caused by a local solder paste printing abnormality generated by the SMT mounting process, the compensation can be performed by printing a normal conductive pad 600 with other solder paste, so that the occurrence of sound pickup leakage or non-essential sound signal pickup of the MEMS microphone due to the open loop of solder paste soldering can be significantly reduced; in addition, the plurality of conductive pads 600 are soldered to an external circuit board together, increasing a soldering area, thereby further enhancing soldering reliability.

Specifically, the external circuit board may be a flexible circuit board, a rigid-flex board, a rigid board, or other PCB board.

Optionally, the number of the conductive pads 600 is 2, 3, 4, 5, 6, etc., and the specific number may be set according to specific requirements, which is not particularly limited herein.

Preferably, the number of the conductive pads 600 is 3 to 5. The 3-5 conductive bonding pads 600 are arranged on the circuit board 100, so that the condition that the MEMS microphone has sound-collecting leakage or picks up unnecessary sound signals can be obviously reduced, the gain effect brought by continuously increasing the number of the conductive bonding pads 600 is not obvious on the basis, and the preparation cost and the manufacturing difficulty can be increased.

Optionally, the conductive pad 600 is provided with a metalized hole for electrically connecting the front side and the back side of the circuit board 100.

Specifically, the shape of the conductive pad 600 may be a circular ring shape, a square ring shape, an irregular ring shape, etc., and is not particularly limited herein.

Preferably, referring to fig. 2, the conductive pad 600 is annular, a plurality of conductive pads 600 are sleeved to form a concentric circle, and the sound inlet 500 is located at a center of the concentric circle. The plurality of conductive pads 600 are arranged in concentric circles, which is less difficult to manufacture and has an aesthetic effect.

Specifically, the shape of the wiring board 100 may be square, circular, triangular, irregular, etc., and is not particularly limited herein.

Specifically, the cross-sectional shape of the housing 200 may be square, circular, triangular, irregular, etc., and is not particularly limited thereto.

For convenience of industrial production and better application effect, please refer to fig. 3, the shape of the circuit board 100 is preferably circular, and the cross-sectional shape of the housing 200 is set to be circular correspondingly, so that the housing 200 and the circuit board 100 are packaged to form a circular MEMS microphone; in addition, the round MEMS microphone with the round edge design has an aesthetic effect.

Optionally, the housing 200 is hermetically attached to the circuit board 100 by solder paste or conductive silver paste to form an electrical connection.

Optionally, the MEMS acoustic sensor 300 and the ASIC chip 400 are connected to the circuit board 100, and the connection manner may be by 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 700.

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 800.

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

the plurality of annular conductive bonding pads 600 are arranged on the circuit board 100 to surround the sound inlet 500, so that the condition that sound-collecting sound leaks or non-necessary sound signals are collected due to open-loop solder paste welding of the conductive bonding pads 600 caused by SMT mounting process defects of the MEMS microphone can be remarkably reduced; in addition, the plurality of conductive pads 600 are soldered to an external circuit board together, increasing a soldering area, thereby further enhancing soldering reliability.

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. A MEMS microphone, comprising: the circuit board, the shell, the ASIC chip and the MEMS acoustic sensor;

2. The MEMS microphone of claim 1, wherein the conductive pad has a shape of any one of a circular ring shape, a square ring shape, and an irregular ring shape.

3. The MEMS microphone of claim 2, wherein the conductive pads are circular, a plurality of the conductive pads are sleeved to form a concentric circle, and the sound inlet hole is located at a center of the concentric circle.

4. The MEMS microphone of claim 1, wherein the wiring board has a shape of any one of a circle, a square, and an irregular shape.

5. The MEMS microphone of claim 1, wherein the cross-sectional shape of the housing is any one of circular, square, and irregular.

6. The MEMS microphone of claim 1, wherein the conductive pad has a metalized hole formed therein.

7. The MEMS microphone of claim 1, wherein the housing is hermetically attached and electrically connected to the circuit board by solder paste or conductive silver paste.

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

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

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