CN210641074U

CN210641074U - MEMS microphone

Info

Publication number: CN210641074U
Application number: CN201922090145.6U
Authority: CN
Inventors: 孙宁杨
Original assignee: Goertek Techology Co Ltd
Current assignee: Goertek Microelectronics Inc
Priority date: 2019-11-27
Filing date: 2019-11-27
Publication date: 2020-05-29
Anticipated expiration: 2029-11-27

Abstract

The utility model discloses a MEMS microphone, which comprises a substrate, a shell, an MEMS chip, a dustproof component and a waterproof component, wherein the shell is connected with the substrate to form a cavity; the MEMS chip is arranged in the cavity and connected with the substrate; the substrate is provided with a sound hole penetrating through the substrate at a position opposite to the MEMS chip; the dustproof member and the waterproof member are disposed on a sound passage from the sound hole to the MEMS chip. The MEMS microphone has small volume and high component precision, so high dustproof and waterproof requirements are required, and the dustproof member and the waterproof member are arranged in the MEMS microphone together, so that the dustproof and waterproof functions can be realized under the condition that the overall size of the MEMS microphone is not increased.

Description

MEMS microphone

Technical Field

The utility model relates to a receive electro-acoustic transducer field a little, specifically, the utility model relates to a MEMS microphone.

Background

An MEMS (Micro-Electro-Mechanical System) microphone is an electric transducer manufactured by micromachining technology, and has the characteristics of small volume, good phase characteristics, low noise, and the like. With the development of miniaturization and thinning of electronic devices, MEMS microphones are widely used in various electronic devices.

The traditional MEMS microphone has small volume and high manufacturing precision, and has very high requirements on dust prevention and water prevention, and the common dust prevention and water prevention operation is to add a complicated and high-weight component at the position outside the sound hole, so that the whole height of the whole MEMS microphone is increased, and the development requirement of modern industry on the lightness and thinness of electronic products is not facilitated.

Disclosure of Invention

An object of the utility model is to provide a MEMS microphone, this MEMS microphone has dustproof and waterproof dual function, and dustproof and waterproof structure is little moreover, light in weight.

According to a first aspect of the present invention, there is provided a MEMS microphone, comprising:

a substrate;

the shell is covered on the substrate, and a cavity is formed between the shell and the substrate;

the MEMS chip is arranged in the cavity and connected with the substrate;

the sound hole is arranged on the substrate and opposite to the MEMS chip;

a dust-proof member and a water-proof member disposed on a sound passage from the acoustic hole to the MEMS chip;

the dust-proof member is configured to prevent foreign matter from entering from the acoustic hole into the MEMS chip;

the waterproof member is configured to prevent liquid from entering into the MEMS chip.

Preferably, a support part for supporting the MEMS chip is disposed on the substrate;

the supporting part comprises a top surface and side walls connected with two ends of the top surface.

Preferably, the MEMS chip has a back cavity, and the top surface of the support portion is provided with a first through hole therethrough at a position opposite to the back cavity, the first through hole being configured to communicate the back cavity with the acoustic hole.

Preferably, the shape of the first through hole is one or a combination of more than one of a circle, a square, a rectangle and a hexagon, and the diameter of the inscribed circle of the first through hole is 6-15 μm.

Preferably, the dust-proof member includes a first dust-proof mesh and a second dust-proof mesh;

the first dustproof net is arranged on one side, far away from the cavity, of the substrate, and a plurality of through second through holes are formed in the positions, corresponding to the sound holes, of the first dustproof net;

the second dust screen with the both ends lateral wall of supporting part is connected, be provided with a plurality of third through-holes that link up on the second dust screen.

Preferably, the thickness of the first dust screen ranges from 30 μm to 80 μm, the shape of the second through hole is one or a combination of more than one of a circle, a square, a rectangle and a hexagon, and the diameter of the inner tangent circle of the second through hole ranges from 5 μm to 10 μm.

Preferably, the thickness range of the second dust screen is 20-50 μm, the shape of the third through hole is one or a combination of more than one of a circle, a square, a rectangle and a hexagon, and the diameter range of the inner tangent circle of the third through hole is 2-6 μm.

Preferably, the waterproof member is disposed between the second dust-proof net and the top surface of the support portion.

Preferably, the waterproof member includes a waterproof membrane and fixing parts provided at edges of the waterproof membrane, the fixing parts being connected with both end side walls of the support part;

the waterproof membrane is one or the combination of two of a PI membrane and a PTFE membrane, the thickness range of the PI membrane is 15-30 mu m, and the pore diameter range of the PI membrane is 0.05-0.5 mu m;

the thickness of the PTFE membrane ranges from 20 to 30 μm, and the pore diameter of the PTFE membrane ranges from 0.05 to 0.5 μm.

Preferably, a groove is arranged at a position on the substrate, which is connected with the supporting part, and the depth of the groove ranges from 50 to 120 μm.

The technical effect of the utility model lies in, through having dustproof and waterproof dual function component in MEMS microphone inside setting, on the basis that does not increase MEMS microphone overall structure, reached dustproof and waterproof effect, guaranteed that MEMS microphone structure is little, light in weight's characteristics.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments of the invention, which proceeds with reference to the accompanying drawings.

Drawings

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

Fig. 1 is a schematic structural diagram of an MEMS microphone according to the present invention;

fig. 2 is a schematic view of a first through hole structure of a first dust screen according to the present invention;

fig. 3 is a schematic structural view of a second dust screen of the present invention;

fig. 4 is a schematic structural diagram of a supporting portion of the present invention.

Wherein: 1-a substrate; 2-a shell; 3-a MEMS chip; 4-an ASIC chip; 5-a cavity; 6-sound hole; 7-a support; 8-a first via; 9-the back cavity; 10-gold wire; 11-a first dust screen; 12-a second dust screen; 13-a second via; 14-a third via; 15-a water-resistant membrane; 16-a fixed part; 17-grooves.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: unless specifically stated otherwise, 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 invention.

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

Referring to fig. 1, the utility model discloses a MEMS microphone, which comprises a substrate 1, a shell 2, a MEMS chip 3, a dustproof member and a waterproof member, wherein the substrate 1 is used for supporting the whole MEMS microphone; the shell 2 is covered on the substrate 1, and the shell 2 is connected with the substrate 1 to form a cavity 5; the MEMS chip 3 is arranged in the cavity 5 and is connected with the substrate 1; the substrate 1 is provided with a sound hole 6 penetrating through the substrate 1 at a position opposite to the MEMS chip 3; the dustproof member and the waterproof member are arranged on the sound channel from the sound hole 6 to the MEMS chip 3; the dust-proof member is configured to prevent foreign matter from entering from the sound hole 6 into the MEMS chip 3 during an external sound is transmitted into the MEMS chip 3; the waterproofing member is configured to prevent liquid from entering into the MEMS chip 3 during the transmission of external sound into the MEMS chip 3.

The MEMS microphone has small volume and high component precision, so high dustproof and waterproof requirements are required, and the dustproof member and the waterproof member are arranged in the MEMS microphone together, so that the dustproof and waterproof functions can be realized under the condition that the overall size of the MEMS microphone is not increased.

In a possible embodiment of the present invention, a supporting portion 7 for supporting the MEMS chip 3 is provided between the substrate 1 and the MEMS chip 3, the supporting portion 7 may be an inverted U shape, including a top surface and a side wall connected to both ends of the top surface. The support portion 7 can play a role of supporting the MEMS chip 3 and providing the dust-proof member and the waterproof member, so that the dust-proof member and the waterproof member are separately arranged and spaced at a certain distance, and thus, the protection function of the dust-proof member and the waterproof member can be respectively exerted.

Further, the MEMS chip 3 of the present embodiment has a back cavity 9. Referring to fig. 4, a plurality of first through holes 8 penetrating through the upper and lower portions of the top surface of the support portion 7 are disposed at positions opposite to the back cavity 9, the plurality of first through holes 8 may be separated from each other or communicated with each other, the first through holes 8 may be one or a combination of one or more of a circle, a square, a rectangle, and a hexagon, and a diameter of an inscribed circle of the first through holes 8 is 6 to 15 μm. The first through hole 8 on the support 7 is configured to allow external sound to quickly pass into the back cavity 9 of the MEMS chip 3 through the sound hole 6.

Specifically, the dust-proof member of the present embodiment includes a first dust-proof mesh 11 and a second dust-proof mesh 12, the first dust-proof mesh 11 is disposed on a side of the substrate 1 away from the cavity 5, a thickness of the first dust-proof mesh 11 ranges from 30 μm to 80 μm, the second dust-proof mesh 12 is connected to sidewalls of two ends of the supporting portion 7, and a thickness of the second dust-proof mesh 12 ranges from 20 μm to 50 μm.

Specifically, the material of the dust-proof member may be an inorganic material such as graphene or an organic polymer material such as polyethylene. The selection of the thickness ranges of the first dust-proof screen 11 and the second dust-proof screen 12 requires a combination of material type parameters and the stability and quality of the dust-proof structure. For the graphene dustproof member, the graphene has very high mechanical strength performance, good flexibility and lower density, so that the graphene dustproof member can meet the requirement of stability by arranging a thinner dustproof net; for the polyethylene dustproof member, because the mechanical strength of polyethylene is slightly poor, but the price is low, the polyethylene dustproof member can select a dustproof film with a relatively thick thickness to meet the requirement of stability, and meanwhile, the quality is ensured not to be increased more.

Referring to fig. 2, a plurality of second through holes 13 penetrating through the first dust screen 11 are formed in positions corresponding to the sound holes 6, and the second through holes 13 are spaced from each other; the shape of the second through hole 13 is one or a combination of more than one of a circle, a square, a rectangle and a hexagon, and the diameter range of an inscribed circle of the second through hole 13 is 5-10 μm. Referring to fig. 3, a plurality of third through holes 14 are formed through the second dust screen 12, and the third through holes 14 are spaced apart from each other. The shape of the third through hole 14 is one or a combination of more than one of a circle, a square, a rectangle and a hexagon, and the diameter range of an inscribed circle of the third through hole 14 is 2-6 μm.

The particle size of dust particles easy to propagate in the air is generally several micrometers to several hundred micrometers, and in the process of transmitting external sound into the interior of the speaker, the first through holes 13 of the first dust-proof screen 11 are contacted, the second through holes 13 can block dust with the particle size of above 10 μm and part of dust with the particle size of below 10 μm (PM10) outside the speaker, even if a small amount of dust enters the interior of the speaker, the second protection of the third through holes 14 can be provided, and dust particles below 10 μm (PM10) and even below 2.5 μm (PM2.5) can be blocked from entering the back cavity 9 of the EMS chip 3.

Specifically, the waterproof member of the present embodiment is disposed between the second dust-proof net 12 and the top surface of the support portion 7, and includes a waterproof membrane 15 and fixing portions 16 disposed at edges of the waterproof membrane, and the fixing portions 16 are connected to both end side walls of the support portion 7; the waterproof membrane can be one or the combination of two of a PI membrane and a PTFE membrane, the thickness of the PI membrane ranges from 15 to 30 μm, and the pore diameter of the PI membrane ranges from 0.05 to 0.5 μm; the thickness of the PTFE membrane ranges from 20 to 30 μm, and the pore diameter of the PTFE membrane ranges from 0.05 to 0.5 μm.

After dust which is introduced into the sound from outside is substantially blocked by the dust-proof member, part of water molecules may be carried in the sound, and at this time, the water-proof member may block the water molecules carried in the sound to the outside of the water-proof film. The surfaces of the PI film and the PTFE film can reach more than one billion micropores per square centimeter, the diameter of each micropore ranges from 0.05 mu m to 0.5 mu m, and the diameter of each micropore is hundreds of times smaller than the diameter of water molecules ranging from 20 mu m to 100 mu m, so that water drops can not pass through the micropores, and the micropore structure can achieve excellent waterproof function. And the PI film and the PTFE film have the advantages of high and low temperature resistance, good insulativity and good adhesion, and can improve the service life and the structural stability of the loudspeaker. The fixing portion 16 may be a hot-melt adhesive material having high and low temperature resistance and good insulation properties, and bonds the waterproof film 15 to the side walls of both ends of the supporting portion 7.

Furthermore, the substrate 1 of the present embodiment is provided with a groove 17 at a position connected to the supporting portion 7, and the depth of the groove 17 ranges from 50 μm to 120 μm. On one hand, the groove 17 is arranged to firmly fix the supporting part 7 on the surface of the groove 17, and the fixing mode can be welding or bonding; on the other hand, by adjusting the depth of the groove 17, the distance between the first dust-proof net 11 and the second dust-proof net 12 can be controlled, thereby improving the acoustic performance of the speaker.

Further, the speaker of the present embodiment further includes an ASIC chip 4 disposed in the cavity 5 and electrically connected to the substrate 1, and the MEMS chip 3 and the ASIC chip 4 are electrically connected by a gold wire 10. The MEMS chip 3 can receive sound from the outside and convert the sound into an electric signal, the ASIC chip 4 receives the electric signal sent by the MEMS chip 3 and processes the electric signal, then the ASIC chip 4 outputs the processed electric signal to the substrate 1, and finally the electric signal is output to the outside through the substrate 1.

Although certain specific embodiments of the present invention have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the invention. 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 invention. The scope of the invention is defined by the appended claims.

Claims

1. A MEMS microphone, comprising:

a substrate (1);

the shell (2) is covered on the substrate (1), and the shell (2) and the substrate (1) form a cavity (5);

the MEMS chip (3) is arranged in the cavity (5) and is connected with the substrate (1);

the sound hole (6), the said sound hole (6) is set up in the said base plate (1) and said MEMS chip (3) relative position;

a dust-proof member and a water-proof member provided on a sound passage from the sound hole (6) to the MEMS chip (3);

the dust-proof member is configured to prevent foreign matter from entering from the acoustic hole (6) into the MEMS chip (3);

the waterproofing member is configured to prevent liquid from entering into the MEMS chip (3).

2. A MEMS microphone according to claim 1, characterized in that the substrate (1) is provided with a support (7) for supporting the MEMS chip (3);

the supporting part (7) comprises a top surface and side walls connected with two ends of the top surface.

3. A MEMS microphone according to claim 2, characterized in that the MEMS chip (3) has a back cavity (9), the top surface of the support (7) is provided with a first through hole (8) therethrough at a position opposite to the back cavity (9), the first through hole (8) being configured to communicate the back cavity (9) with the acoustic aperture (6).

4. A MEMS microphone according to claim 3, characterized in that the shape of the first via (8) is one or a combination of more than one of circular, square, rectangular, hexagonal, and the diameter of the inscribed circle of the first via (8) is in the range of 6-15 μm.

5. A MEMS microphone according to claim 2, wherein the dust-proof means comprises a first dust-proof mesh (11) and a second dust-proof mesh (12);

the first dust screen (11) is arranged on one side, far away from the cavity (5), of the substrate (1), and a plurality of through second through holes (13) are formed in the first dust screen (11) and correspond to the sound holes (6);

the second dust screen (12) is connected with the side walls of the two ends of the supporting part (7), and a plurality of through third through holes (14) are formed in the second dust screen (12).

6. A MEMS microphone as claimed in claim 5, wherein the thickness of the first dust screen (11) is in the range of 30-80 μm, the shape of the second through hole (13) is one or more of circular, square, rectangular and hexagonal, and the diameter of the inscribed circle of the second through hole (13) is in the range of 5-10 μm.

7. The MEMS microphone according to claim 5, wherein the thickness of the second dust screen (12) is in the range of 20-50 μm, the shape of the third through hole (14) is one or more of circular, square, rectangular and hexagonal, and the diameter of the inscribed circle of the third through hole (14) is in the range of 2-6 μm.

8. A MEMS microphone as claimed in claim 5, characterized in that the waterproofing means are arranged between the second dust screen (12) and the top surface of the support (7).

9. A MEMS microphone according to claim 8, wherein the waterproof member comprises a waterproof membrane (15) and a fixing portion (16) provided at an edge of the waterproof membrane, the fixing portion (16) being connected to both end side walls of the support portion (7);

10. A MEMS microphone according to claim 2, characterized in that the substrate (1) is provided with a groove (17) at the location where it is connected to the support (7), the groove (17) having a depth in the range of 50-120 μm.