CN216795281U - MEMS device, microphone and electronic product - Google Patents

Abstract

The application discloses MEMS device, microphone and electronic product, the MEMS device includes: the circuit board is provided with a first acoustic through hole which is communicated along the thickness direction of the circuit board; the shell is arranged on the circuit board, the shell and the circuit board are matched to define a containing cavity, and a second acoustic through hole communicated with the containing cavity is formed in one side of the shell, which is back to the circuit board; the MEMS chip is arranged on the circuit board and positioned in the accommodating cavity, one side of the MEMS chip corresponds to the first acoustic through hole, and the other side of the MEMS chip corresponds to the second acoustic through hole; the cover body, the cover body is established in one side towards the circuit board of casing, and the cover body is equipped with the passageway, passageway and second acoustics through-hole with hold the chamber intercommunication. The MEMS device of this application sets up the cover body in the position department of second acoustics through-hole, guarantees that the sound wave gets into second acoustics through-hole and contacts the MEMS chip more intensively, improves the sensitivity of MEMS device, eliminates the echo, promotes the interference killing feature of MEMS device, promotes and produces the property ability.

Description

MEMS device, microphone and electronic product

Technical Field

The present disclosure relates to the field of micro-electromechanical systems, and more particularly, to a MEMS device, a microphone, and an electronic product having the MEMS device.

Background

The existing microphone is usually provided with a sound hole on the top surface of the shell. For example, a TOP type microphone may be understood as a microphone in which the sound hole and the land are separately provided, not in an arrangement on the same circuit board.

The top surface of the shell is provided with the sound holes, so that sound waves are difficult to be intensively led into the shell through the sound holes and contact with the MEMS chip, and the sensitivity and the anti-interference capability of the MEMS chip are reduced. Meanwhile, as the sound hole is formed in the top surface of the shell, impurities such as dust and the like easily enter the shell through the sound hole, and the performance and the service life of the microphone are influenced.

SUMMERY OF THE UTILITY MODEL

An object of the present application is to provide a new technical solution for a MEMS device, which can at least solve the problem in the prior art that sound waves are difficult to concentrate and guide into a housing through a sound hole.

According to a first aspect of the present application, there is provided a MEMS device comprising: the circuit board is provided with a first acoustic through hole which penetrates through the circuit board along the thickness direction of the circuit board; the shell is arranged on the circuit board, the shell and the circuit board are matched to define an accommodating cavity, and a second acoustic through hole communicated with the accommodating cavity is formed in one side of the shell, which is back to the circuit board; the MEMS chip is arranged on the circuit board and is positioned in the accommodating cavity, one side of the MEMS chip corresponds to the first acoustic through hole, and the other side of the MEMS chip corresponds to the second acoustic through hole; the cover body is arranged on one side, facing the circuit board, of the shell and provided with a channel, and the channel is communicated with the second acoustic through hole and the accommodating cavity.

Optionally, a first end of the channel faces the second acoustic via, a second end of the channel faces the MEMS chip, and a radial dimension of the channel in a direction from the first end to the second end gradually increases.

Optionally, one end of the cover body facing the MEMS chip is provided with a dust screen, and the shape of the dust screen corresponds to the shape of the second end of the channel.

Optionally, the cross-sectional shape of the MEMS chip is square, and the radial dimension of the dust screen is not less than the cross-sectional length of the MEMS chip.

Optionally, the dust screen is a polytetrafluoroethylene microporous membrane.

Optionally, the cover body is a steel cover or a plastic cover.

Optionally, the first acoustic via and the second acoustic via are disposed directly opposite to each other.

Optionally, the MEMS device further comprises: the ASIC chip is arranged on the circuit board and is positioned in the accommodating cavity, and the MEMS chip is electrically connected with the ASIC chip through a metal lead.

According to a second aspect of the present application, there is provided a microphone comprising the MEMS device described in the above embodiments.

According to a third aspect of the present application, there is provided an electronic product comprising the MEMS device described in the above embodiments.

According to the MEMS device provided by the embodiment of the utility model, the first acoustic through hole is arranged on the circuit board, the second acoustic through hole is arranged at the top of the shell, and the cover body is arranged at the position of the second acoustic through hole, so that sound waves can enter the second acoustic through hole more intensively and contact the MEMS chip, the sensitivity of the MEMS device is effectively improved, the MEMS device can conveniently pick up a single sound wave signal in a noisy environment scene, echoes are effectively eliminated, the anti-interference capability of the MEMS device is improved, and the product performance is improved.

Further features of the present application and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which is to be read in connection with the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and together with the description, serve to explain the principles of the application.

FIG. 1 is a schematic structural diagram of a MEMS device in accordance with an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a MEMS device of an embodiment of the utility model.

Reference numerals:

a MEMS device 100;

a wiring board 10; a first acoustic via 11;

a housing 20; a second acoustic through hole 21;

a cover body 30; a channel 31;

a dust screen 40;

a MEMS chip 50;

an ASIC chip 60;

a metal lead 70.

Detailed Description

Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the application, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

The MEMS device 100 according to an embodiment of the present invention is described in detail below with reference to the drawings.

As shown in fig. 1 and 2, a MEMS device 100 according to an embodiment of the present invention includes a wiring board 10, a case 20, a MEMS chip 50, and a cap 30.

Specifically, the wiring board 10 is opened with a first acoustic through hole 11 penetrating in the thickness direction thereof. The shell 20 is arranged on the circuit board 10, the shell 20 and the circuit board 10 cooperate to define a containing cavity, and a second acoustic through hole 21 communicated with the containing cavity is arranged on one side of the shell 20, which faces away from the circuit board 10. The MEMS chip 50 is disposed on the circuit board 10, and the MEMS chip 50 is located in the accommodating cavity, one side of the MEMS chip 50 corresponds to the first acoustic through hole 11, and the other side of the MEMS chip 50 corresponds to the second acoustic through hole 21. The cover 30 is provided on the side of the housing 20 facing the circuit board 10, and the cover 30 is provided with a passage 31, and the passage 31 communicates with the second acoustic through hole 21 and the accommodating chamber.

In other words, referring to fig. 1 and 2, the MEMS device 100 according to the embodiment of the present invention is mainly composed of the wiring board 10, the case 20, the MEMS chip 50, and the cap 30. The MEMS device 100(Micro-Electro-Mechanical System, Micro Electro-Mechanical System) has the characteristics of small volume, good frequency response, noise ground, and the like, and is one of the essential devices of the mobile terminal. In the MEMS device 100, a first acoustic through hole 11 penetrating through a circuit board 10 in the thickness direction is formed. The sound of the external environment can be introduced from the first acoustic through hole 11. The wiring board 10 is referred to as a Printed circuit board { Printed circuit boards }, or a Printed circuit board. The casing 20 is disposed on the circuit board 10, the casing 20 covers the circuit board 10 as a housing cover, and the casing 20 and the circuit board 10 cooperate to form a receiving cavity. The side of the casing 20 facing away from the circuit board 10, i.e., the top surface of the casing 20, is provided with a second acoustic through hole 21, and the second acoustic through hole 21 communicates with the accommodating chamber. The external environment can be introduced into the accommodation chamber from the first acoustic through hole 11 and the second acoustic through hole 21, respectively.

The MEMS chip 50 is disposed on the wiring board 10, and the MEMS chip 50 is located in the accommodation chamber. One side of the MEMS chip 50 corresponds to the first acoustic via 11, and the other side of the MEMS chip 50 corresponds to the second acoustic via 21. The one side and the other side of the MEMS chip 50 may be understood as portions facing the first acoustic via 11 and the second acoustic via 21, respectively. The MEMS chip 50 can sense sound (or referred to as sound pressure) introduced from the first acoustic via 11 and the second acoustic via 21 and convert the sound into an electrical signal.

The cover 30 is disposed on a side of the housing 20 facing the circuit board 10 (an inner wall of the top surface of the housing 20), and the cover 30 is located in the accommodating chamber. The cover 30 is provided with a through passage 31, and the passage 31 communicates with the second acoustic through hole 21 and the accommodating chamber. The sound of the external environment is intensively guided into the accommodating cavity through the second acoustic through hole 21 via the cover 30, and the MEMS chip 50 contacts and senses the sound of the external environment. Through setting up in the cover body 30 of the 21 intercommunication of second acoustics through-hole at casing 20 inner wall, can guarantee that the sound wave can get into second acoustics through-hole 21 and contact MEMS chip 50 more intensively, effectively improve MEMS device 100's sensitivity, be convenient for MEMS device 100 picks up single sound wave signal under noisy environmental scene, effectively eliminate the echo, promote MEMS device 100's interference killing feature, promote product property ability.

Therefore, according to the MEMS device 100 of the embodiment of the present invention, the first acoustic through hole 11 is disposed on the circuit board 10, the second acoustic through hole 21 is disposed on the top of the housing 20, and the cover 30 is disposed at the position of the second acoustic through hole 21, so that it can be ensured that the sound waves can enter the second acoustic through hole 21 and contact the MEMS chip 50 more intensively, the sensitivity of the MEMS device 100 is effectively improved, the MEMS device 100 can pick up a single sound wave signal in a noisy environment scene, the echo is effectively eliminated, the anti-interference capability of the MEMS device 100 is improved, and the product performance is improved.

According to an embodiment of the present invention, the first end of the channel 31 faces the second acoustic via 21, the second end of the channel 31 faces the MEMS chip 50, and the radial dimension of the channel 31 in the direction from the first end to the second end gradually increases.

That is, as shown in fig. 2, the first end of the passage 31 in the cover 30 faces the second acoustic through hole 21, and the first end of the passage 31 communicates with the second acoustic through hole 21. The second end of passageway 31 is towards MEMS chip 50, is convenient for transmit environmental sound for MEMS chip 50 through cover body 30 more concentratedly, effectively improves MEMS chip 50's sensitivity, and the MEMS device 100 of being convenient for picks up single sound wave signal under noisy environmental scene, effectively eliminates the echo, promotes MEMS device 100's interference killing feature, promotes and produces the property ability. As shown in fig. 1, the cover 30 of the present invention may be provided with a trumpet-like configuration, with the radial dimension of the passage 31 gradually increasing in the direction from the first end to the second end. The first end and the second end of the cover body 30 are the relative both ends of the cover body 30, the radial dimension of the first end of the cover body 30 is equivalent to the aperture size of the second acoustic through hole 21, the radial dimension of the second end of the cover body 30 is greater than the aperture of the second acoustic through hole 21, after the environmental sound is led in from the second acoustic through hole 21, the sound can be diffused out of the cover body 30 to reach the MEMS chip 50, the effective contact surface between the MEMS chip 50 and the sound is further improved, the sensitivity of the MEMS chip 50 is improved, and the MEMS device 100 can pick up a single sound wave signal in a noisy environment scene conveniently.

Meanwhile, the horn-shaped cover body 30 is arranged, echoes can be effectively eliminated, the anti-interference capability of the MEMS device 100 is improved, and the product performance is improved. Of course, the cover 30 is not limited to the trumpet-shaped structure design in this application, and other designs that can facilitate the concentrated conduction of the sound wave should fall within the scope of this application.

According to an embodiment of the present invention, the end of the cap 30 facing the MEMS chip 50 is provided with a dust screen 40, and the shape of the dust screen 40 corresponds to the shape of the second end of the channel 31.

In other words, referring to fig. 1 and 2, one end of the cap 30 facing the MEMS chip 50 is provided with a dust-proof mesh 40, and the shape of the dust-proof mesh 40 corresponds to the shape of the second end of the channel 31. Through set up dust screen 40 at the second end of cover body 30, can effectively block impurity such as environmental dust, steam and get into MEMS device 100 when the leading-in cover body 30 of environmental sound, guarantee that the internal environment of MEMS device 100 is clean, improve MEMS device 100's performance reliability, prolong MEMS device 100's life.

In some embodiments of the present invention, the cross-sectional shape of the MEMS chip 50 is square, and the radial dimension of the dust screen 40 is not less than the cross-sectional length of the MEMS chip 50.

That is to say, as shown in fig. 1 and fig. 2, the MEMS chip 50 may be designed as a square device, the radial dimension of the dust-proof mesh 40 is not less than the length of the cross section of the MEMS chip 50, and it is ensured that the orthogonal projection of the dust-proof mesh 40 (the second end of the cover 30) on the MEMS chip 50 can cover the MEMS chip 50, so that the environmental sound can directly contact with the maximum area of the MEMS chip 50 after being guided out through the cover 30, thereby effectively improving the sensitivity of the MEMS chip 50 and improving the performance of the MEMS device 100. Optionally, the radial dimension of the dust screen 40 is comparable to the cross-sectional length of the MEMS chip 50, improving the sensitivity of the MEMS chip 50.

According to one embodiment of the present invention, the dust screen 40 is a polytetrafluoroethylene microporous membrane. That is to say, the dust screen 40 can adopt polytetrafluoroethylene microporous membrane (PB resin film), and polytetrafluoroethylene microporous membrane can also prevent impurity such as dust, liquid from passing through when can satisfying the passing through of sound air current, satisfies the dustproof of MEMS device 100, prevents the demand of steam, guarantees that the internal environment of MEMS device 100 is clean, improves the performance reliability of MEMS device 100, prolongs the life of MEMS device 100. Of course, in the present application, the dust screen 40 may also be made of ePTFE fabric, which is formed by laminating a polytetrafluoroethylene microporous membrane with a common fabric through a special process, and has excellent dust and liquid preventing effects. In the present application, the specific material of the dust-proof net 40 is not limited, and as long as the material having dust-proof and liquid-proof properties is within the protection scope of the present application, detailed description thereof is omitted.

According to one embodiment of the utility model, cover 30 is a steel or plastic cover.

In other words, the cover body 30 can adopt a steel cover, for example, the cover body 30 can be made of a steel sheet with a thinned plate, so that sound waves can enter the second acoustic through hole 21 and contact the MEMS chip 50 more intensively, the sensitivity of the MEMS device 100 is effectively improved, the MEMS device 100 can conveniently pick up a single sound wave signal in a noisy environment scene, echoes are effectively eliminated, the anti-interference capability of the MEMS device 100 is improved, and the product performance is improved. The cap 30 and the housing 20 may be welded together, which improves the structural stability of the MEMS device 100. The cap 30 may also be made of plastic, reducing the weight of the MEMS device 100.

According to an embodiment of the present invention, the first acoustic via 11 and the second acoustic via 21 are disposed to face each other. That is, referring to fig. 1 and fig. 2, the first acoustic through hole 11 on the circuit board 10 and the second acoustic through hole 21 on the top surface of the housing 20 may be disposed opposite to each other, and the first acoustic through hole 11 and the second acoustic through hole 21 are respectively located at the central positions of two sides of the MEMS chip 50, which is beneficial for the MEMS chip 50 to pick up an acoustic signal and improve the overall performance of the MEMS device 100.

According to an embodiment of the utility model, the MEMS device 100 further comprises: the ASIC chip 60, the ASIC chip 60 is located on the circuit board 10, and the ASIC chip 60 is located in the accommodation cavity, and the MEMS chip 50 and the ASIC chip 60 are electrically connected through a metal lead 70.

In other words, as shown in fig. 1 and fig. 2, the MEMS device 100 further includes an ASIC chip 60 (ASIC), the capacitance of the MEMS chip 50 changes correspondingly with the change of the incoming sound, and the ASIC chip 60 processes and outputs the changed capacitance signal to pick up the sound. The ASIC chip 60 is disposed on the wiring board 10, and the ASIC chip 60 is located in the housing cavity, the ASIC chip 60 being disposed side by side with the MEMS chip 50. The MEMS chip 50 and the ASIC chip 60 are electrically connected by metal wires 70. The ASIC chip 60 and the circuit board are also electrically connected by leads.

The ambient sound is introduced into the receiving chamber through the first acoustic through hole 11, the second acoustic through hole 21, and the cover 30, and the MEMS chip 50 induces the sound wave in the receiving chamber and stably converts the induced sound wave into an electrical signal. The capacitance of the MEMS chip 50 will change correspondingly with the difference of the input sound signal, and then the ASIC chip 60 is used to process the changed capacitance signal and output the processed capacitance signal to the circuit board 10, thereby realizing the sound pickup.

In summary, according to the MEMS device 100 of the embodiment of the present invention, the first acoustic through hole 11 is disposed on the circuit board 10, the second acoustic through hole 21 is disposed on the top of the casing 20, and the cover 30 is disposed at the position of the second acoustic through hole 21, so that it can be ensured that the sound wave can enter the second acoustic through hole 21 and contact the MEMS chip 50 more intensively, the sensitivity of the MEMS device 100 is effectively improved, the MEMS device 100 can pick up a single sound wave signal in a noisy environment scene, the echo is effectively eliminated, the anti-interference capability of the MEMS device 100 is improved, and the product performance is improved. Meanwhile, the dust screen 40 is arranged at the second end of the cover body 30, so that when environmental sound is introduced into the cover body 30, impurities such as environmental dust and water vapor can be effectively prevented from entering the MEMS device 100, the cleanness of the internal environment of the MEMS device 100 is guaranteed, the performance reliability of the MEMS device 100 is improved, and the service life of the MEMS device 100 is prolonged.

According to a second aspect of the present application, a microphone is provided, comprising the MEMS device 100 of the above embodiments. Since the MEMS device 100 according to the embodiment of the present invention has the above technical effects, the microphone according to the embodiment of the present invention also has corresponding technical effects, that is, the microphone according to the embodiment of the present invention employs the MEMS device 100, so that it can be ensured that sound waves can enter the second acoustic through hole 21 and contact the MEMS chip 50 more intensively, the sensitivity of the MEMS device 100 is effectively improved, the MEMS device 100 can pick up a single sound wave signal in a noisy environment scene, an echo is effectively eliminated, and the anti-interference capability of the microphone is improved. Meanwhile, the dust screen 40 is arranged at the second end of the cover body 30, so that when environmental sound is led into the cover body 30, impurities such as environmental dust and water vapor can be effectively prevented from entering the MEMS device 100, the cleanness of the internal environment of the MEMS device 100 is guaranteed, the performance reliability of the microphone is improved, and the service life of the microphone is prolonged.

According to a third aspect of the present application, an electronic product is provided, comprising the MEMS device 100 of the above embodiments. The electronic product of the present application includes a complete machine housing and the MEMS device 100 of the above embodiment disposed in the complete machine housing. The electronic product may be a product with the MEMS device 100, such as a mobile phone, a tablet computer, or a headset.

Since the MEMS device 100 according to the embodiment of the present invention has the above technical effects, the electronic product according to the present invention also has corresponding technical effects, that is, the electronic product according to the present application adopts the MEMS device 100 according to the above embodiment, so that it can be ensured that the sound waves can enter the second acoustic through hole 21 and contact the MEMS chip 50 more intensively, the sensitivity of the MEMS device 100 is effectively improved, the MEMS device 100 can pick up a single sound wave signal in a noisy environment scene, the echo is effectively eliminated, and the anti-interference capability of the electronic product is improved. Meanwhile, the dust screen 40 is arranged at the second end of the cover body 30, so that when environmental sound is introduced into the cover body 30, impurities such as environmental dust and water vapor can be effectively prevented from entering the MEMS device 100, the cleanness of the internal environment of the MEMS device 100 is guaranteed, the performance reliability of an electronic product is improved, and the service life of the electronic product is prolonged.

Of course, the working principles and other structures of the MEMS device 100, the microphone and the electronic product of the present application are understood and can be implemented by those skilled in the art, and will not be described in detail in the present application.

Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present application. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present application. The scope of the application is defined by the appended claims.

Claims (10)

1. A MEMS device, comprising:

the circuit board is provided with a first acoustic through hole which penetrates through the circuit board along the thickness direction of the circuit board;

the shell is arranged on the circuit board, the shell and the circuit board are matched to define an accommodating cavity, and a second acoustic through hole communicated with the accommodating cavity is formed in one side of the shell, which is back to the circuit board;

the MEMS chip is arranged on the circuit board and is positioned in the accommodating cavity, one side of the MEMS chip corresponds to the first acoustic through hole, and the other side of the MEMS chip corresponds to the second acoustic through hole;

the cover body is arranged on one side, facing the circuit board, of the shell and provided with a channel, and the channel is communicated with the second acoustic through hole and the accommodating cavity.

2. The MEMS device, as recited in claim 1, wherein a first end of the channel is toward the second acoustic via, a second end of the channel is toward the MEMS chip, and a radial dimension of the channel in a direction from the first end to the second end gradually increases.

3. The MEMS device, as recited in claim 2, wherein an end of the cap facing the MEMS chip is provided with a dust screen having a shape corresponding to a shape of the second end of the channel.

4. The MEMS device, as recited in claim 3, wherein the MEMS chip has a square cross-sectional shape, and wherein the radial dimension of the dust screen is not less than the cross-sectional length of the MEMS chip.

5. The MEMS device, as recited in claim 3, wherein the dust screen is a polytetrafluoroethylene microporous membrane.

6. The MEMS device, as recited in claim 1, wherein the cap is a steel cap or a plastic cap.

7. The MEMS device, as recited in claim 1, wherein the first acoustic via and the second acoustic via are disposed directly opposite.

8. The MEMS device, as recited in claim 1, further comprising: the ASIC chip is arranged on the circuit board and is positioned in the accommodating cavity, and the MEMS chip is electrically connected with the ASIC chip through a metal lead.

9. A microphone comprising a MEMS device as claimed in any one of claims 1 to 8.

10. An electronic product comprising a MEMS device according to any of claims 1-8.

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