CN216491060U

CN216491060U - Miniature microphone and electronic equipment

Info

Publication number: CN216491060U
Application number: CN202123282111.0U
Authority: CN
Inventors: 庞胜利
Original assignee: Goertek Microelectronics Inc
Current assignee: Goertek Microelectronics Inc
Priority date: 2021-12-23
Filing date: 2021-12-23
Publication date: 2022-05-10
Anticipated expiration: 2031-12-23

Abstract

The utility model discloses a miniature microphone and electronic equipment, the miniature microphone comprises a shell, a signal processing chip and an MEMS chip, the shell is provided with an installation cavity, and the shell is also provided with a first sound hole which communicates the installation cavity with the outside; the signal processing chip is arranged in the mounting cavity, the signal processing chip and the wall of the mounting cavity are enclosed to form an acoustic cavity, and the signal processing chip is provided with a second sound hole for communicating the mounting cavity and the acoustic cavity; the MEMS chip is arranged in the acoustic cavity and is electrically connected with the signal processing chip, and the MEMS chip and the cavity wall of the acoustic cavity are enclosed to form a back cavity. The utility model discloses technical scheme has reduced miniature microphone's size.

Description

Miniature microphone and electronic equipment

Technical Field

The utility model relates to an acoustoelectric product technical field, in particular to miniature microphone and applied this miniature microphone's electronic equipment.

Background

With the progress of society and the development of electronic technology, electronic products have become more and more important in daily life, for example, mobile phones, tablet computers and the like are almost indispensable for people to carry about, and in electronic products such as mobile phones and the like, microphones are required to be arranged to collect voice signals in order to realize functions such as conversation. In order to meet the performance requirements and miniaturization trend of electronic products, a MEMS (Micro-Electro-Mechanical System) microphone is generally used. The MEMS microphone is a packaging structure consisting of a shell and a circuit board, an MEMS sound-electricity chip and an ASIC chip are arranged on the surface of the circuit board inside the packaging structure, external sound acts on the MEMS sound-electricity chip, and the ASIC chip performs signal processing to realize sound inlet effect.

In the related art, the MEMS acousto-electric chip and the ASIC chip are arranged side by side, which occupies too much lateral area of the circuit board, resulting in too large lateral size of the microphone.

SUMMERY OF THE UTILITY MODEL

The main object of the present invention is to provide a miniature microphone, which is intended to reduce the size of the miniature microphone.

In order to achieve the above object, the present invention provides a miniature microphone comprising:

the device comprises a shell, a first sound hole and a second sound hole, wherein the shell is provided with a mounting cavity and is also provided with the first sound hole which is communicated with the mounting cavity and the outside;

the signal processing chip is arranged in the mounting cavity, an acoustic cavity is formed by the signal processing chip and the wall of the mounting cavity in a surrounding mode, and the signal processing chip is provided with a second sound hole for communicating the mounting cavity and the acoustic cavity; and

the MEMS chip is arranged in the sound cavity and is electrically connected with the signal processing chip, and the MEMS chip and the cavity wall of the sound cavity are enclosed to form a back cavity.

Optionally, the housing comprises:

the signal processing chip is arranged on the substrate and forms the acoustic cavity with the substrate in an enclosing manner, and the MEMS chip is arranged on the substrate and forms the rear cavity with the substrate in an enclosing manner; and

the shell covers the signal processing chip and encloses with the substrate to form the installation cavity, and the shell is provided with the first sound hole.

Optionally, the first sound hole is coaxially disposed with the second sound hole;

and/or the first sound hole and the second sound hole are arranged right opposite to the rear cavity.

Optionally, a groove is formed in one side, facing the MEMS chip, of the substrate, and the groove is communicated with the rear cavity.

Optionally, the outer surface of the housing is provided with a barrier coating.

Optionally, the material of the housing is a metal material, and the housing is grounded.

Optionally, an avoidance groove is formed in one side, facing the substrate, of the signal processing chip, and a groove wall of the avoidance groove and the substrate enclose to form the acoustic cavity;

and/or, the signal processing chip includes mounting bracket and chip body, the mounting bracket with the base plate is connected, the mounting bracket is equipped with and dodges the groove, dodge the cell wall in groove with the base plate encloses to close and forms the acoustic cavity, the chip body is located the mounting bracket, and with the base plate electricity is connected.

Optionally, the signal processing chip is fixed to the substrate by gluing;

and/or the MEMS chip is fixed with the substrate in an adhesive manner.

Optionally, a first bonding pad is arranged on one side of the substrate facing the MEMS chip, and the MEMS chip is connected to the first bonding pad through a connection line;

and/or a second bonding pad is arranged on one side of the substrate facing the signal processing chip, and the signal processing chip is connected with the second bonding pad through a connecting wire;

and/or a third bonding pad is arranged on one side of the substrate, which faces away from the MEMS chip, and the third bonding pad is used for connecting external equipment.

The utility model also provides an electronic equipment, including the main part and as above miniature microphone, miniature microphone is located the main part.

The utility model discloses technical scheme is through locating the installation intracavity of casing with the signal processing chip to protect it. Meanwhile, the signal processing chip and the wall of the mounting cavity are enclosed to form an acoustic cavity, and the MEMS chip is arranged in the acoustic cavity. The casing is equipped with the first sound hole of the external and installation cavity of intercommunication, and the second sound hole of intercommunication installation cavity and sound cavity is seted up to the signal processing chip, so, the MEMS chip of external sound in entering into the sound cavity through first sound hole and second sound hole, and the cavity wall enclosure of MEMS chip and sound cavity is formed with the back cavity to make the MEMS chip realize sound signal's collection. The signal processing chip is electrically connected with the MEMS chip so as to process the sound signal. Therefore, the MEMS chip is covered by the signal processing chip, so that the signal processing chip and the MEMS chip are prevented from being arranged side by side, and the transverse size of the miniature microphone is reduced.

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 longitudinal sectional view of an embodiment of a miniature microphone according to the present invention;

fig. 2 is a longitudinal sectional view of another embodiment of the miniature microphone of the present invention.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				100	Miniature microphone	2	Signal processing chip
1	Shell body	21	Acoustic chamber
				11	Substrate	22	Second sound hole
111	Groove	3	MEMS chip
				12	Outer casing	31	Rear cavity
121	First sound hole	4	Connecting wire
				13	Mounting cavity

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 all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit ly 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 miniature microphone 100.

As shown in fig. 1, in the embodiment of the present invention, the miniature microphone 100 includes a housing 1, a signal processing chip 2 and an MEMS chip 3, the housing 1 is formed with a mounting cavity 13, and the housing 1 is further provided with a first sound hole 121 communicating the mounting cavity 13 with the outside; the signal processing chip 2 is arranged in the mounting cavity 13, the signal processing chip 2 and the wall of the mounting cavity 13 enclose to form a sound cavity 21, and the signal processing chip 2 is provided with a second sound hole 22 communicating the mounting cavity 13 and the sound cavity 21; the MEMS chip 3 is arranged in the acoustic cavity 21 and is electrically connected with the signal processing chip 2, and the MEMS chip 3 and the cavity wall of the acoustic cavity 21 are enclosed to form a back cavity 31.

In this embodiment, the microphone is a pressure sensor that finally converts a sound pressure signal into an electrical signal, and a small-sized microphone manufactured by using a Micro Electro Mechanical technology is called an MEMS (Micro-Electro-Mechanical System) microphone or a Micro microphone. Here, the shape of the mounting cavity 13 may be a square, a cylinder, a sphere, or the like, which is not limited herein. The signal processing chip 2 and the MEMS chip 3 are mounted in the mounting cavity 13 and protected by the case 1.

In this embodiment, the signal processing chip 2 is an ASIC chip, and it can be understood that the MEMS chip 3 mainly includes a back plate and a diaphragm, and the back plate and the diaphragm form two plates of a parallel plate capacitor. The back plate is mechanically rigid with a perforated design that allows air to pass through. The diaphragm is flexible and displaces under the impact of acoustic pressure. In order to realize the sound receiving function of the MEMS chip 3, the housing 1 is provided with a first sound hole 121, which facilitates the inflow of the sound signal. Meanwhile, the signal processing chip 2 covers the MEMS chip 3, the signal processing chip 2 is provided with a second sound hole 22, and the MEMS chip 3 is configured to sense and detect a sound signal flowing from the first sound hole 121 and the second sound hole 22, and convert the sound signal into an electrical signal and transmit the electrical signal to the signal processing chip 2. The signal processing chip 2 is used for providing a voltage for the MEMS chip 3, and processing and amplifying a signal output by the MEMS chip 3, so that the miniature microphone 100 provides a sound receiving function for an electronic device to which the miniature microphone 100 is applied.

It can be understood that the signal processing chip 2 is disposed in the mounting cavity 13 and encloses with the cavity wall of the mounting cavity 13 to form the acoustic cavity 21, the MEMS chip 3 is disposed in the acoustic cavity 21, the signal processing chip 2 is provided with a second sound hole 22 communicating the mounting cavity 13 and the acoustic cavity 21, sound can enter the acoustic cavity 21 through the second sound hole 22, and the cavity after the sound passes through the diaphragm of the MEMS chip 3 is the rear cavity 31. That is, the MEMS chip 3 and the cavity wall of the acoustic cavity 21 enclose to form a back cavity 31, i.e. an acoustic back cavity, and the size of the back cavity 31 easily affects the acoustic effect of the sound receiving of the micro microphone 100. Further, the signal processing chip 2 and the MEMS chip 3 are electrically connected so that the MEMS chip 3 transmits an electrical signal to the signal processing chip 2.

The utility model discloses technical scheme is through locating in the installation cavity 13 of casing 1 with signal processing chip 2 to protect it. Meanwhile, the signal processing chip 2 and the wall of the mounting cavity 13 enclose to form an acoustic cavity 21, and the MEMS chip 3 is arranged in the acoustic cavity 21. Casing 1 is equipped with the first sound hole 121 that communicates the external world and installation cavity 13, and signal processing chip 2 sets up the second sound hole 22 of intercommunication installation cavity 13 and sound cavity 21, so, the MEMS chip 3 in the external sound enters into sound cavity 21 through first sound hole 121 and second sound hole 22, and MEMS chip 3 encloses with the chamber wall of sound cavity 21 and closes and is formed with back cavity 31 to make MEMS chip 3 realize the collection of sound signal. The signal processing chip 2 is electrically connected to the MEMS chip 3 to process the sound signal. In this way, by disposing the signal processing chip 2 to cover the MEMS chip 3, the signal processing chip 2 and the MEMS chip 3 are prevented from being arranged side by side, so as to reduce the lateral size of the miniature microphone 100.

In one embodiment, the first sound hole 121 is disposed coaxially with the second sound hole 22.

In this embodiment, the first sound hole 121 and the second sound hole 22 may be circular holes, square holes, or other irregular hole shapes, and are not limited herein. The first sound hole 121 and the second sound hole 22 are arranged coaxially, so that external sound can pass through the first sound hole 121 and then pass through the second sound hole 22 to enter the sound cavity 21, and a sound pressure signal is collected by the MEMS chip 3. Alternatively, the diameter of the first sound hole 121 may be the same as or different from the diameter of the second sound hole 22, and is not limited herein. In this embodiment, the central axes of the first sound hole 121 and the second sound hole 22 may coincide with the central axis of the MEMS chip 3, that is, the first sound hole 121 and the second sound hole 22 are opposite to the center of the MEMS chip 3, so that external sound pressure directly impacts the diaphragm of the MEMS chip 3; of course, in other embodiments, the central axes of the first sound hole 121 and the second sound hole 22 may also be staggered from the central axis of the MEMS chip 3, so as to reduce the direct impact of the external sound pressure on the diaphragm of the MEMS chip 3.

In one embodiment, the housing 1 includes a substrate 11 and a shell 12, the signal processing chip 2 is disposed on the substrate 11 and encloses with the substrate 11 to form an acoustic cavity 21, and the MEMS chip 3 is disposed on the substrate 11 and encloses with the substrate 11 to form a back cavity 31; the housing 12 covers the signal processing chip 2 and encloses with the substrate 11 to form a mounting cavity 13, and the housing 12 is opened with a first sound hole 121.

It can be understood that the substrate 11 is a PCB board, and the PCB board is printed with a circuit to implement a corresponding electrical function, and can be selectively designed according to actual needs. The signal processing chip 2 and the substrate 11 enclose to form an acoustic cavity 21, and the MEMS chip 3 is disposed in the acoustic cavity 21 and encloses with the substrate 11 to form a back cavity 31. The signal processing chip 2 and the MEMS chip 3 are electrically connected to the substrate 11, and the two chips can be electrically connected by a circuit printed on the substrate 11. The longitudinal section of the housing 12 is in a U-shape, the housing 12 may be a metal shell formed integrally or a non-metal shell coated with a metal material, and the housing 12 encloses a closed installation cavity 13 with one end of the opening direction and the substrate 11. Optionally, the first sound hole 121 is opened at a side of the housing 12 opposite to the substrate 11, and it is understood that the substrate 11 is used for mounting and connecting with the electronic device, so that the first sound hole 121 picks up sound towards the outside of the electronic device, and the sound is collected conveniently.

As shown in fig. 2, in an embodiment, a side of the substrate 11 facing the MEMS chip 3 is provided with a groove 111, and the groove 111 is disposed in communication with the rear cavity 31.

In this embodiment, the substrate 11 is provided with a groove 111 corresponding to the rear cavity 31 and communicating with the rear cavity 31, that is, the rear cavity 31 is located above the groove 111, so as to achieve the effect of enlarging the size of the rear cavity 31, thereby improving the acoustic performance of the miniature microphone 100. The distance between the two opposite side walls of the groove 111 may be equal to the distance between the two opposite side walls of the rear cavity 31, so as to enlarge the size of the rear cavity 31. Of course, the distance between the two opposite side walls of the groove 111 may be greater than the distance between the two opposite side walls of the back cavity 31 and smaller than the distance between the two opposite outer wall surfaces of the MEMS chip 3, that is, the MEMS chip 3 is prevented from being mounted in the groove 111, so as to expand the back cavity 31.

In one embodiment, the outer surface of the housing 12 is provided with a barrier coating.

In this embodiment, the shielding coating is specifically an electromagnetic wave shielding coating, and the electromagnetic wave shielding coating is a functional coating that is formed by doping conductive particles in a chemical solvent, and can be sprayed on engineering plastics such as ABS, glass fiber reinforced plastics, wood, cement wall surfaces, and other non-metallic materials to shield electromagnetic waves. The shielding coating has conductivity, and it can be understood that the shielding coating is connected to the ground terminal of the substrate 11, and when the external electromagnetic wave is emitted to the shielding coating, the ground terminal of the substrate 11 is led away, thereby effectively preventing the external electromagnetic wave from interfering with the chip inside the miniature microphone 100. The shielding coating can be coated on the outer surface of the encapsulating glue in a spraying mode, and can also be coated on the outer surface of the encapsulating glue in a wiping mode.

In one embodiment, the housing 12 is made of metal, and the housing 12 is grounded.

In this embodiment, the housing 12 may be an integrally formed metal shell, and is disposed such that when the external electromagnetic wave is emitted to the shielding coating, the external electromagnetic wave is guided away by the ground terminal of the substrate 11, thereby effectively preventing the external electromagnetic wave from interfering with the chip inside the miniature microphone 100.

In an embodiment, an avoiding groove is formed on a side of the signal processing chip 2 facing the substrate 11, and a wall of the avoiding groove and the substrate 11 enclose to form the acoustic cavity 21. In this embodiment, an avoiding groove is etched on a side of the signal processing chip 2 facing the substrate 11, and when the signal processing chip 2 is connected to the substrate 11, a groove wall of the avoiding groove and the substrate 11 enclose to form the acoustic cavity 21.

In other embodiments, the signal processing chip 2 includes a mounting frame and a chip body, the mounting frame is connected to the substrate 11, the mounting frame is provided with an avoiding groove, a groove wall of the avoiding groove and the substrate 11 enclose to form the acoustic cavity 21, and the chip body is disposed on the mounting frame and electrically connected to the substrate 11. In this embodiment, the longitudinal section of the mounting frame may be in an inverted U shape, and covers the MEMS chip 3, and meanwhile, the chip body is mounted on the mounting frame and electrically connected to the substrate 11. Specifically, can set up the chip body and install in the one end that the base plate 11 was kept away from to the mounting bracket, and be equipped with in the mounting bracket and lead electrical pillar and switch on with base plate 11, the chip body is connected with base plate 11 electricity through this leading electrical pillar. Of course, the chip body may be electrically connected to the substrate 11 by gold wires, copper wires, or the like.

In one embodiment, the signal processing chip 2 is fixed to the substrate 11 by gluing; in this embodiment, the end surface of the signal processing chip 2 is fixed on the surface of the substrate 11 by glue, so as to be firmly connected with the substrate 11.

Optionally, the MEMS chip 3 is adhesively fixed with the substrate 11. In this embodiment, the end surface of the MEMS chip 3 may also be fixed on the surface of the substrate 11 by glue, so as to be firmly connected to the substrate 11. Alternatively, the MEMS chip 3 may be adhesively fixed to the bottom wall of the groove 111.

In an embodiment, a side of the substrate 11 facing the MEMS chip 3 is provided with a first bonding pad, and the MEMS chip 3 is connected to the first bonding pad through a connection line 4. In this embodiment, in order to facilitate connection of the MEMS chip 3 and the substrate 11, first pads are disposed on the substrate 11, and specifically, there may be 2 or 3 first pads for selection or backup.

Optionally, a second pad is disposed on a side of the substrate 11 facing the signal processing chip 2, and the signal processing chip 2 is connected to the second pad through a connection line 4; in this embodiment, in order to facilitate connection between the signal processing chip 2 and the substrate 11, second pads are further disposed on the substrate 11, and specifically, there may be 2 or 3 second pads for selection or backup.

Optionally, a side of the substrate 11 facing away from the MEMS chip 3 is provided with a third pad, and the third pad is used for connecting an external device. In this embodiment, the third pads may be conveniently soldered to the main board circuit of a specific product by SMT or other processes, and there may be 3 or 4 specific third pads, so as to improve the stability of structural connection and data transmission.

The utility model also provides an electronic equipment, this electronic equipment include main part and miniature microphone 100, and above-mentioned embodiment is referred to this miniature microphone 100's concrete structure, 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. Wherein the mini microphone 100 is provided at the main body.

The electronic device may be a wearable electronic device, such as a smart watch or a bracelet, or may be a mobile terminal, such as a mobile phone or a notebook computer, or other devices that need to have an audio-electrical conversion function, which is not limited herein.

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

Claims

1. A miniature microphone, comprising:

2. The miniature microphone of claim 1, wherein said housing comprises:

3. The miniature microphone of claim 2, wherein said first sound aperture is disposed coaxially with said second sound aperture;

4. The microphone of claim 2, wherein a side of the substrate facing the MEMS chip is provided with a groove, and the groove is disposed in communication with the back cavity.

5. The miniature microphone of claim 2, wherein an outer surface of said housing is provided with a barrier coating.

6. The microphone of claim 2, wherein the housing is made of metal, and the housing is grounded.

7. The microphone according to any one of claims 2 to 6, wherein an evasion groove is formed on a side of the signal processing chip facing the substrate, and the signal processing chip is connected to the substrate such that the substrate covers a notch of the evasion groove and encloses the acoustic cavity;

8. The microphone according to any one of claims 2 to 6, wherein the signal processing chip is adhesively fixed to the substrate;

and/or the MEMS chip is fixed with the substrate in an adhesive manner.

9. The microphone according to any one of claims 2 to 6, wherein a side of the substrate facing the MEMS chip is provided with a first pad, the MEMS chip being connected to the first pad by a connection line;

10. An electronic device comprising a main body and the miniature microphone according to any one of claims 1 to 9, the miniature microphone being provided in the main body.