CN218387898U

CN218387898U - Microphone and electronic equipment

Info

Publication number: CN218387898U
Application number: CN202222821814.4U
Authority: CN
Inventors: 张庆; 刘波
Original assignee: Goertek Microelectronics Inc
Current assignee: Goertek Microelectronics Inc
Priority date: 2022-10-25
Filing date: 2022-10-25
Publication date: 2023-01-24
Anticipated expiration: 2032-10-25

Abstract

The utility model discloses a microphone and electronic equipment. The microphone comprises a shell, an MEMS chip and a waterproof membrane; the shell is provided with an installation cavity and is also provided with a sound hole; the MEMS chip is arranged in the mounting cavity, and is surrounded with the cavity wall of the mounting cavity to form a sound cavity, and the sound hole is communicated with the sound cavity; the MEMS chip comprises a vibrating diaphragm provided with a pressure relief hole, and the vibrating diaphragm is arranged facing the sound hole; the waterproof membrane covers the sound hole. The utility model discloses technical scheme is through setting up the water proof membrane in closing cap sound hole, then can prevent on the one hand that water from getting into in the sound cavity and through the pressure release hole on the vibrating diaphragm get into the installation cavity inside, on the other hand water proof membrane has better compliance and vibration characteristic for the sound wave that the external world sent still can make the water proof membrane vibration, and pass the effect that the water proof membrane got into in the sound cavity in order to further arouse the vibrating diaphragm vibration on the MEMS chip.

Description

Microphone and electronic device

Technical Field

The utility model relates to an electron device technical field, in particular to microphone and electronic equipment of using this microphone.

Background

In order to balance the internal and external air pressures and adjust the low-frequency performance of a conventional MEMS (Micro-Electro-Mechanical System) microphone, air release holes are required to be formed in the MEMS diaphragm, and the size of the air release holes is usually large. Under the above conditions, when the microphone encounters water, water can enter the package through the air leakage hole on the MEMS diaphragm, so that the product performance is affected and even the product is invalid.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a microphone aims at improving and has great disappointing hole and make steam get into the inside problem of microphone through this disappointing hole easily because of the vibrating diaphragm on the chip.

In order to achieve the above object, the present invention provides a microphone, which includes a housing, an MEMS chip, and a waterproof film; the shell is provided with an installation cavity and is also provided with a sound hole; the MEMS chip is arranged in the mounting cavity, and is surrounded with the cavity wall of the mounting cavity to form a sound cavity, and the sound hole is communicated with the sound cavity; the MEMS chip comprises a vibrating diaphragm provided with a pressure relief hole, and the vibrating diaphragm is arranged facing the sound hole; the waterproof membrane covers the sound hole.

Optionally, the waterproof membrane is arranged outside the installation cavity; and/or, the waterproof membrane is an air-impermeable waterproof membrane.

Optionally, the microphone still includes the support frame, the one end of support frame connect in the casing and towards deviating from the direction of installation cavity extends, the support frame is kept away from the one end of installation cavity is equipped with the installing port, the water proof membrane install in the installing port.

Optionally, the housing comprises:

a protective shell; and

the protective shell is welded on the circuit board through a welding ring and forms the mounting cavity together with the circuit board in an enclosing manner; the circuit board is provided with the sound hole, and the MEMS chip is electrically connected with the circuit board.

Optionally, the weld ring comprises:

the inner welding ring is arranged between the protective shell and the circuit board, and is provided with a first air leakage hole communicated with the mounting cavity; and

the outer welding ring is arranged outside the inner welding ring in a surrounding mode and is arranged at a distance from the inner welding ring to form a spacing channel; the outer welding ring is provided with a second air leakage hole communicated with the outside, and the first air leakage hole and the second air leakage hole are communicated with the interval channel.

Optionally, defining a weld edge of the inner welding ring, which is provided with the first air leakage hole, as a reference weld edge; the outer weld ring includes:

a first weld edge parallel to and disposed adjacent to the reference weld edge; and

the second welds the limit, the second weld the limit with first parallel relative setting of limit, just seted up on the second welds the limit the second is lost heart.

Optionally, the first air release hole is formed in the middle of the reference welding edge, and the second air release hole is formed in the middle of the second welding edge.

Optionally, the diameter of the first air leakage hole is less than or equal to 3 micrometers;

and/or the diameter of the second air leakage hole is less than or equal to 3 microns.

Optionally, the protective case comprises:

the inner cover and the circuit board jointly enclose to form the mounting cavity, and the inner cover is welded with the circuit board through the inner welding ring; and

the outer cover is arranged outside the inner cover and welded with the circuit board through the outer welding ring.

The utility model also provides an electronic equipment, including foretell microphone.

The utility model discloses technical scheme is through having seted up the sound hole on the casing, installs the MEMS chip in the installation cavity of casing, and the MEMS chip has towards the vibrating diaphragm of sound hole, and the vibrating diaphragm closes with the chamber wall of installation cavity encloses jointly and forms the sound cavity, makes to make sound wave accessible sound hole get into the sound cavity to make the vibrating diaphragm vibration, so that the MEMS chip experiences this sound wave signal. In addition, through the waterproof membrane that sets up the closing cap sound hole, then can prevent on the one hand that water from getting into in the sound chamber and through the pressure release hole on the vibrating diaphragm get into the installation cavity inside, on the other hand waterproof membrane has better compliance and vibration characteristic for the sound wave that the external world sent still can make the waterproof membrane vibration, and pass the effect that the waterproof membrane got into the sound intracavity in order to further arouse the vibrating diaphragm vibration on the MEMS chip.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

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

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

fig. 3 is a schematic structural diagram of an embodiment of a solder ring in a microphone according to the present invention;

fig. 4 is a schematic side view of the microphone of the present invention.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				100	Shell body	110	Protective shell
111	Inner cover	112	Outer cover
				120	Circuit board	121	Sound hole
101	Mounting cavity	102	Acoustic chamber
				200	MEMS chip	210	Vibrating diaphragm
211	Pressure relief hole	220	Body
				230	Back pole	300	Waterproof film
400	Supporting frame	500	Inner welding ring
				510	Reference welding edge	511	A first air release hole
600	Outer welding ring	610	First welding edge
				620	Second welding edge	621	Second air release hole
700	Spacing channel

The objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, back, 8230; \8230;) are provided in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the attached drawings), and if the specific posture is changed, the directional indications are correspondingly changed.

In addition, if there is a description relating to "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

The utility model provides a microphone.

In the embodiment of the present invention, as shown in fig. 1, the microphone includes a housing 100, a MEMS chip 200, and a waterproof film 300; the shell 100 is provided with a mounting cavity 101, and the shell 100 is also provided with a sound hole 121; the MEMS chip 200 is arranged in the installation cavity 101, and is surrounded with the cavity wall of the installation cavity 101 to form an acoustic cavity 102, and the acoustic hole 121 is communicated with the acoustic cavity 102; the MEMS chip 200 includes a diaphragm 210 having a pressure relief hole 211, the diaphragm 210 being disposed facing the sound hole 121; the waterproof membrane 300 covers the sound hole 121.

The housing 100 of the microphone is formed with a mounting cavity 101, and the MEMS chip 200 or other chips are mounted in the mounting cavity 101, so as to protect the components mounted in the mounting cavity 101. It can be understood that, the MEMS chip 200 generally needs to be electrically connected to the circuit board 120, the circuit board 120 may also be disposed in the housing 100, or the circuit board 120 may serve as a part of the housing 100, that is, the housing 100 may include a protective shell 110 and the circuit board 120, the protective shell 110 is a cover structure, and the protective shell 110 covers the circuit board 120 and encloses with the circuit board 120 to form the mounting cavity 101. The MEMS chip 200 installed in the installation cavity 101 includes a diaphragm 210, the diaphragm 210 divides the installation cavity 101 into two acoustic cavities 102, wherein the acoustic cavity 102 that communicates the acoustic hole 121 is a front cavity, external sound can enter the front cavity through the acoustic hole 121, the diaphragm 210 vibrates under the impact of the sound wave, the MEMS chip 200 converts the vibration signal of the diaphragm 210 into an electrical signal for transmission, and then the electrical connection is performed to the circuit board 120, and other chips (for example, ASIC chips) electrically connected to the MEMS chip 200 amplify the signal output by the MEMS chip 200, thereby realizing the sound receiving effect of the microphone. In general, in order to balance air pressure inside and outside the microphone, the diaphragm 210 has a pressure relief hole 211 with a larger size, and since the diaphragm 210 is disposed opposite to the sound hole 121, external water is likely to enter the microphone through the sound hole 121 and the pressure relief hole 211 in sequence. The utility model discloses microphone among the technical scheme still includes water proof membrane 300, and water proof membrane 300 sets up with vibrating diaphragm 210 relatively to closing cap sound hole 121, then this water proof membrane 300 can block in steam gets into sound chamber 102, and then further avoids steam to get into the deeper in casing 100 through pressure release hole 211 on vibrating diaphragm 210. In addition, the waterproof membrane 300 has better compliance and vibration characteristics, and sound waves emitted from the outside can still make the waterproof membrane 300 vibrate and pass through the waterproof membrane 300 into the acoustic cavity 102 to further cause the vibration of the diaphragm 210 on the MEMS chip 200.

Specifically, the waterproof film 300 may be an air-impermeable waterproof film 300, and in this case, the material of the waterproof film 300 may be an acrylic polymer plastic material, a polyimide material, a silicone film, a rubber film, or the like. By providing the waterproof film 300 as the air-impermeable waterproof film 300, the waterproof performance of the waterproof film 300 is further improved, and it is prevented that small molecules of moisture enter the inside of the microphone through the waterproof film 300. Of course, in another example, the waterproof membrane 300 may also be a breathable waterproof membrane 300 in order to ensure the air pressure inside and outside the microphone is balanced. Namely, the film layer is provided with a microporous structure, so that the film layer can be understood that water particles are very fine in a water vapor state, and can smoothly permeate into a capillary to the other side according to the capillary movement principle, so that the air permeability phenomenon is generated. After the water vapor is condensed into water drops, the particles become large, and water molecules cannot smoothly separate from the water drops to permeate to the other side under the action of the surface tension of the water drops, so that the water permeation is prevented, and the waterproof breathable film has a waterproof function. The gas can pass through the waterproof breathable film to keep the internal and external air pressure balance of the installation cavity 101, and the water drops can not pass through the waterproof breathable film to achieve the waterproof effect. In addition, when the waterproof film 300 covers the sound hole 121, it may be disposed outside the mounting cavity 101, or may be disposed inside the mounting cavity 101, as long as water can be prevented from entering the inside of the housing 100 through the pressure relief hole 211 on the diaphragm 210. When the waterproof film 300 covers the sound hole 121, the waterproof film may be directly adhered to the wall of the installation cavity 101, or a support member connected to the housing 100 may be provided, and the waterproof film 300 is provided on the support member.

The utility model discloses technical scheme is through having seted up the sound hole 121 on casing 100, installs MEMS chip 200 in casing 100's the installation cavity 101, and MEMS chip 200 has the vibrating diaphragm 210 towards sound hole 121, and vibrating diaphragm 210 encloses jointly with the chamber wall of installation cavity 101 and closes formation sound cavity 102, makes to make sound wave accessible sound hole 121 get into sound cavity 102 to make vibrating diaphragm 210 vibrate, so that MEMS chip 200 experiences this sound wave signal. In addition, by providing the waterproof membrane 300 for sealing the acoustic hole 121, on one hand, water can be prevented from entering the acoustic cavity 102 and entering the installation cavity 101 through the pressure relief hole 211 on the diaphragm 210, and on the other hand, the waterproof membrane 300 has better compliance and vibration characteristics, so that the sound waves emitted from the outside can still make the waterproof membrane 300 vibrate and pass through the waterproof membrane 300 to enter the acoustic cavity 102 to further cause the effect of vibrating the diaphragm 210 on the MEMS chip 200.

Further, as shown in fig. 1, a waterproof membrane 300 is provided outside the installation cavity 101.

By arranging the waterproof membrane 300 outside the installation cavity 101, the waterproof membrane 300 can block water outside before entering the acoustic cavity 102, so that a better waterproof effect is achieved. Specifically, the waterproof membrane 300 may be adhered to the outer wall of the installation cavity 101, or the waterproof membrane 300 may be spaced apart from the outer wall of the installation cavity 101, and the waterproof membrane 300 is connected to the housing 100 through another connection structure.

In an embodiment, as shown in fig. 1, the microphone further includes a supporting frame 400, one end of the supporting frame 400 is connected to the casing 100, and the other end extends in a direction away from the mounting cavity 101, an installation opening is provided at an end of the supporting frame 400 away from the mounting cavity 101, and the waterproof membrane 300 is installed at the installation opening.

So configured, the waterproof membrane 300 can be connected to the casing 100 through the support frame 400, and a relatively stable state between the casing 100 and the waterproof membrane 300 can also be ensured. Specifically, the supporting bracket 400 may include two supporting rods between which a mounting opening is naturally formed; alternatively, the supporting frame 400 may be a rectangular frame, and a mounting opening is formed on a side wall of the frame away from the mounting cavity 101, so that the waterproof membrane 300 is mounted in the mounting opening. When the supporting frame 400 is connected to the casing 100, the supporting frame may be connected by bonding, welding or other fixing means.

In an embodiment, please refer to fig. 1 and fig. 2 in combination, the casing 100 includes a protective shell 110 and a circuit board 120, the protective shell 110 is welded to the circuit board 120 by a solder ring, and forms a mounting cavity 101 together with the circuit board 120; the circuit board 120 is provided with a sound hole 121, and the MEMS chip 200 is electrically connected with the circuit board 120.

By enclosing the circuit board 120 and the protective shell 110 together to form the mounting cavity 101, the circuit board 120 can serve as a part of the shell 100, thereby reducing the material and volume of the protective shell 110. The protective shell 110 is welded to the circuit board 120 by a solder ring, and a stable connection effect between the protective shell 110 and the circuit board 120 is achieved. Since the MEMS chip 200 is electrically connected to the circuit board 120, the sound hole 121 is formed on the circuit board 120, which is beneficial to the arrangement of the diaphragm 210 on the MEMS chip 200 opposite to the sound hole 121.

Specifically, the MEMS chip 200 may be connected to the circuit board 120 by bonding, the MEMS chip 200 further includes a body 220 and a back electrode 230, one end of the body 220 is bonded to the circuit board 120 and electrically connected to the circuit board 120, the diaphragm 210 is disposed at one end of the body 220 away from the circuit board 120, the diaphragm 210, the body 220 and the circuit board 120 jointly form the acoustic cavity 102, the back electrode 230 is disposed at one side of the diaphragm 210 away from the acoustic hole 121, and the back electrode 230 and the diaphragm 210 form two plates of a parallel plate capacitor.

Further, referring to fig. 1 to 4, the welding ring includes an inner welding ring 500 and an outer welding ring 600, the inner welding ring 500 is disposed between the protective shell 110 and the circuit board 120, and a first air release hole 511 communicating with the mounting cavity 101 is formed at one side of the inner welding ring 500; the outer welding ring 600 is arranged around the inner welding ring 500 and is arranged at an interval with the inner welding ring 500 to form an interval channel 700; the second of outer welding ring 600's one side seted up with external intercommunication loses heart hole 621, and first disappointing hole 511 and second loses heart hole 621 and all communicate interval passageway 700.

Weld ring 500 and outer ring 600 of welding in setting up the interval setting, weld ring 500 in and offer the first disappointing hole 511 with installation cavity 101 intercommunication, weld ring 600 outward and offer the second disappointing hole 621 with external intercommunication, then realized the effect that installation cavity 101 can communicate with the external world to realize the balanced effect of inside and outside atmospheric pressure of microphone. In addition, a first air release hole 511 is formed in the inner welding ring 500, a second air release hole 621 is formed in the outer welding ring 600, the first air release hole 511 and the second air release hole 621 are communicated with the spacing channel 700 between the inner welding ring 500 and the outer welding ring 600, so that the first air release hole 511, the second air release hole 621 and the spacing channel 700 form an air release channel together, and the air release channel is long, so that on one hand, a large sound resistance can be ensured, and external sound is prevented from entering the interior of the microphone shell 100 from the air release channel to influence the performance of the microphone; on the other hand, water is effectively prevented from directly entering the interior of the housing 100. According to the scheme, when the waterproof membrane 300 is the airtight waterproof membrane 300, the balance of the air pressure of the internal and external environments of the microphone can still be ensured.

Specifically, the thickness of the side of the protective case 110 close to the circuit board 120 may be set larger so as to be able to accommodate two layers of solder rings, i.e., to have an arrangement space in which the inner solder ring 500 and the outer solder ring 600 are arranged. Or the protective case 110 may have a double-layered hollow case structure such that the inner welding ring 500 and the outer welding ring 600 are respectively connected to two layers of the double-layered hollow case.

In an embodiment, referring to fig. 1 and fig. 2, the protective casing 110 includes an inner cover 111 and an outer cover 112, the inner cover 111 and the circuit board 120 together enclose to form the mounting cavity 101, and the inner cover 111 is welded to the circuit board 120 through an inner welding ring 500; the outer cover 112 covers the inner cover 111, and the outer cover 112 is welded to the circuit board 120 by an outer solder ring 600.

By arranging the inner cover 111 and the outer cover 112 covering the inner cover 111, the inner cover 111 can be used for arranging the inner welding ring 500 to ensure that the inner welding ring 500 is arranged between the protective shell 110 and the circuit board 120, and similarly, the outer cover 112 can be used for arranging the outer welding ring 600 to ensure that the outer welding ring 600 is arranged between the protective shell 110 and the circuit board 120. In addition, the protective case 110 includes an inner cover 111 and an outer cover 112, so that the protective case 110 can doubly protect components in the mounting cavity 101, further improving external impact resistance or water resistance.

Further, as shown in fig. 3, a reference welding edge 510 is defined as a side of the inner welding ring 500 where the first air release hole 511 is formed; outer weld ring 600 includes a first weld edge 610 and a second weld edge 620, the first weld edge 610 being parallel and disposed adjacent to the reference weld edge 510; the second welding edge 620 is opposite to the first welding edge 610 in parallel, and a second air release hole 621 is formed on the second welding edge 620.

It can be understood that the longer and more tortuous the air release passage formed between the first air release hole 511 and the second air release hole 621, the greater the acoustic resistance and the better the waterproof performance. In this embodiment, through locating first disappointing hole 511 the benchmark of inner welding ring 500 and welding limit 510, the second loses heart hole 621 and locates the one side of keeping away from benchmark welding limit 510, make first disappointing hole 511 and the setting of second disappointing hole 621 opposite direction, thereby it is longer to make the first disappointing hole 511 communicate to the disappointing passageway that second disappointing hole 621 formed, and this route is crooked route, consequently, guarantee the inside and outside atmospheric pressure balance of microphone, on the basis of guaranteeing that the microphone has better low frequency performance, can also further improve the acoustic resistance, prevent effectively that external sound from entering to the installation cavity 101 in through first disappointing hole 511 and influencing microphone self's performance. On the other hand, by making the path of the air leakage assume a curved shape, it is possible to further effectively prevent water from entering the inside of the casing 100. Specifically, the first air-release hole 511 may be disposed at any position of the reference bead 510, the second air-release hole 621 may be disposed at any position of the second bead 620, for example, the first air-release hole 511 and the second air-release hole 621 are diagonally disposed, or a connection line between the first air-release hole 511 and the second air-release hole 621 is perpendicular to the first bead 610 or the reference bead 510 or the second bead 620.

Further, as shown in fig. 3, a first air-release hole 511 is provided in the middle of the reference welding edge 510, and a second air-release hole 621 is provided in the middle of the second welding edge 620.

It can be understood that when the first air-release hole 511 is disposed opposite to the second air-release hole 621, the first air-release hole 511 to the second air-release hole 621 have two communication paths when communicating with each other, and the sum of the two communication paths is equal to the total length of the spacing channel 700. Through locating first disappointing hole 511 in the middle part of benchmark welding edge 510, second disappointing hole 621 locates in the middle part of second welding edge 620, then two communicating paths length when first disappointing hole 511 communicates to second disappointing hole 621 equals to can avoid one of them communicating path to be short and make outside water get into in the microphone easily, perhaps avoid one of them communicating path to be short and make it have bad sound resistance performance.

In one embodiment, the diameter of the first relief hole 511 is less than or equal to 3 microns.

By setting the diameter of the first air release hole 511 to be less than or equal to 3 micrometers, it is ensured that the first air release hole 511 can release air, and at the same time, water is prevented from entering the inside of the installation cavity 101 through the first air release hole 511, so that the microphone is suitable for a deep water environment.

In one embodiment, the diameter of the second venting hole 621 is less than or equal to 3 microns.

Set the diameter through the second hole 621 that loses heart to be less than or equal to 3 microns, then when guaranteeing that the second hole 621 that loses heart can lose heart, still avoid water to get into the second through the second hole 621 that loses heart in the disappointing passageway between hole 621 and the first hole 511 that loses heart, and then avoid water to get into the installation cavity 101 with first hole 511 intercommunication that loses heart to make the microphone be applicable to the deep water environment.

The utility model also provides an electronic equipment, this electronic equipment include the microphone, and the concrete structure of this microphone refers to above-mentioned embodiment, because this electronic equipment has adopted the whole technical scheme of above-mentioned all embodiments, consequently has all beneficial effects that the technical scheme of above-mentioned embodiment brought at least, and the repeated description is no longer given here.

The above only is the preferred embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structure changes made by the contents of the specification and the drawings under the inventive concept of the present invention, or the direct/indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A microphone, comprising:

the device comprises a shell, a sound hole and a sound guide plate, wherein a mounting cavity is formed in the shell, and the shell is also provided with the sound hole;

the MEMS chip is arranged in the mounting cavity, and is encircled together with the wall of the mounting cavity to form an acoustic cavity, and the acoustic hole is communicated with the acoustic cavity; the MEMS chip comprises a vibrating diaphragm provided with a pressure relief hole, and the vibrating diaphragm is arranged facing the sound hole; and

a waterproof membrane covering the sound hole.

2. The microphone of claim 1, wherein the waterproof membrane is disposed outside the mounting cavity; and/or the waterproof membrane is an air-impermeable waterproof membrane.

3. The microphone of claim 2, further comprising a support frame, wherein one end of the support frame is connected to the housing and extends away from the mounting cavity, a mounting opening is formed at one end of the support frame away from the mounting cavity, and the waterproof membrane is mounted at the mounting opening.

4. The microphone of claim 1, wherein the housing comprises:

a protective shell; and

5. The microphone of claim 4, wherein the weld ring comprises:

the inner welding ring is arranged between the protective shell and the circuit board, and is provided with a first air release hole communicated with the mounting cavity; and

6. The microphone of claim 5, wherein the weld edge of the inner weld ring provided with the first relief hole is defined as a reference weld edge; the outer weld ring includes:

the first welding edges are parallel and are arranged close to the reference welding edge; and

the second welds the limit, the second weld the limit with first welding limit parallel relative setting, just seted up on the second welds the limit the second is lost air the hole.

7. The microphone of claim 6, wherein the first relief hole is formed in the middle of the reference weld and the second relief hole is formed in the middle of the second weld.

8. The microphone of claim 6, wherein the diameter of the first relief hole is less than or equal to 3 microns;

9. The microphone of any of claims 5 to 8, wherein the protective case comprises:

10. An electronic device, characterized in that it comprises a microphone according to any one of claims 1 to 9.