CN114786104A

CN114786104A - Microphone structure and voice communication equipment

Info

Publication number: CN114786104A
Application number: CN202210505314.1A
Authority: CN
Inventors: 缪建民; 张金姣
Original assignee: Maigan Microelectronics Shanghai Co ltd
Current assignee: Sv Senstech Wuxi Co ltd
Priority date: 2022-05-10
Filing date: 2022-05-10
Publication date: 2022-07-22

Abstract

The invention discloses a microphone structure and voice communication equipment, and belongs to the technical field of microphones. The microphone structure comprises a hollow shell, a first substrate, an acoustic element, a second substrate, a third substrate and an elastic vibration film, wherein sound signals are conducted by utilizing human bones, when vibration signals are transmitted from the third substrate, the elastic vibration film generates resonance after receiving the vibration signals, vibration generated by the elastic vibration film generates air pressure change in a cavity, and the air pressure signals caused by vibration frequency and amplitude are sensed by the acoustic element. Because the bone conduction sound is used without arranging the sound inlet hole, the noise is effectively reduced, the noise of the surrounding environment is reduced, the conversation is clear, the tone quality is high-definition and has penetrating power, the influence of useless signals such as surrounding noise is reduced, the voice signal of a speaker is kept, and the conversation quality is effectively improved.

Description

Microphone structure and voice communication equipment

Technical Field

The invention relates to the technical field of microphones, in particular to a microphone structure and voice communication equipment.

Background

MEMS (Micro-Electro-Mechanical System) technology is an advanced semiconductor manufacturing process to realize mass production of sensors, drivers, and other devices. The traditional MEMS microphone adopts a conduction mode that an MEMS chip vibrating diaphragm receives airborne voice, and a sound pressure signal is sensed by a high-sensitivity vibrating film of the MEMS chip through a sound inlet hole to convert the sound signal into an electric signal. And the ASIC chip electrically connected with the MEMS chip is used for operating and amplifying the signal and then outputting the signal. The MEMS chip is a micro capacitor formed by a silicon diaphragm and a silicon back plate, and can convert sound pressure change into capacitance change, and then the capacitance change of the ASIC chip is reduced and converted into an electric signal, so that the sound-electricity conversion is realized.

The sensor of the traditional MEMS microphone receives the voice transmitted by air, and includes the voice of the speaker and the noise from the surroundings, and when the noise is large, the microphone is interfered by the noise, such as the surrounding people, mechanical equipment, wind noise, etc., and the quality of the communication is seriously affected.

Therefore, it is desirable to provide a microphone structure and a voice communication device to solve the above problems.

Disclosure of Invention

The invention aims to provide a microphone structure and voice communication equipment, which can effectively reduce noise, reduce noise of the surrounding environment and effectively improve the communication quality.

In order to realize the purpose, the following technical scheme is provided:

a microphone structure comprising:

a hollow-type housing;

the first substrate, the second substrate and the third substrate are sequentially laminated from top to bottom;

the first substrate is provided with a sound transmission hole in a penetrating way along the thickness direction; the second substrate is provided with a first sound cavity; the third substrate is provided with a second sound cavity, and the sound transmission hole, the first sound cavity and the second sound cavity are coaxially arranged;

the hollow shell is arranged on the first substrate in a sealing mode, the hollow shell and the first substrate are arranged in a surrounding mode to form an accommodating cavity, and the acoustic element is arranged on the first substrate and located in the accommodating cavity;

and the elastic vibration film is hermetically arranged at the transition part of the first sound cavity and the second sound cavity.

As an alternative of the microphone structure, the microphone structure further comprises a fixing frame, wherein the elastic vibration film is bonded to one end face of the fixing frame, and the other end face of the fixing frame is bonded to the third substrate.

As an alternative of the microphone structure, the microphone further comprises a mass block, wherein the mass block is adhered to the upper surface of the elastic vibration film and is positioned in the first sound cavity; or

The mass block is adhered to the lower surface of the elastic vibration film and is located in the second sound cavity.

As an alternative of the microphone structure, an air hole is formed in the elastic vibration film and used for adjusting air pressure in the first sound cavity and the second sound cavity.

As an alternative of the microphone structure, the acoustic element includes an MEMS chip and an ASIC chip, the MEMS chip and the ASIC chip are connected by gold wires, the MEMS chip is configured to receive a sound pressure signal from the sound transmission hole and convert the sound pressure signal into an electrical signal, and the ASIC chip is configured to output the electrical signal after operational amplification.

As an alternative of the microphone structure, the MEMS chip and the ASIC chip are both bonded to the same side of the first substrate, and the MEMS chip is disposed at the outlet of the sound transmission hole.

As an alternative to the microphone structure, the elastic diaphragm is a planar membrane.

As an alternative of the microphone structure, the first substrate, the second substrate and the third substrate are all PCB circuit boards, and the first substrate, the second substrate and the third substrate are electrically connected through holes.

As an alternative to the microphone structure, the hollow shell is made of metal.

A voice communication device, comprising the technical solution of the microphone structure as described in any of the above.

Compared with the prior art, the invention has the beneficial effects that:

the microphone structure provided by the invention has the advantages that the accommodating cavity is formed by enclosing the hollow shell and the first substrate, the second substrate and the third substrate are arranged on one side of the first substrate, which is far away from the hollow shell, in a sealing manner, the first sound cavity, the second sound cavity and the sound transmission hole are coaxially arranged, the acoustic element is positioned in the accommodating cavity, the elastic vibration film is arranged at the transition position of the first sound cavity and the second sound cavity in a sealing manner, the transmission of sound signals is carried out by utilizing human bones, the third substrate is abutted against the surface of the human bones, when vibration signals are transmitted from the third substrate, the elastic vibration film generates resonance after receiving the vibration signals, the vibration generated by the elastic vibration film generates air pressure change in the cavity, and the air pressure signals caused by the vibration frequency and amplitude are sensed by the acoustic element. Because the bone conduction sound is utilized without arranging the sound inlet hole, the noise is effectively reduced, the noise of the surrounding environment is reduced, the conversation is clear, the tone quality is high, the penetrating power is high, the influence of useless signals such as surrounding noise is reduced, the voice signal of a conversation person is kept, and the conversation quality is effectively improved.

The voice communication equipment provided by the invention utilizes bone conduction sound without arranging the sound inlet hole, effectively reduces noise, reduces noise of the surrounding environment and effectively improves the communication quality.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and 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 contents of the embodiments of the present invention and the drawings without creative efforts.

Fig. 1 is a cross-sectional view of a microphone structure according to an embodiment of the present invention;

FIG. 2 is a first schematic view of an elastic diaphragm with corrugations according to one embodiment of the present invention;

FIG. 3 is a second schematic view of an elastic diaphragm with corrugations in accordance with one embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an elastic vibration film according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of an elastic vibration film being an elastic metal sheet according to an embodiment of the present invention;

FIG. 6 is a schematic structural view of a fixing frame in a second embodiment of the present invention;

fig. 7 is a cross-sectional view of a microphone structure according to a second embodiment of the present invention.

Reference numerals:

1. a hollow-type housing; 11. an accommodating chamber; 2. a first substrate; 21. a sound transmission hole; 3. an acoustic element; 4. a third substrate; 5. an elastic vibration film; 51. air holes are formed; 6. a mass block; 7. a second substrate; 8. a fixing frame; 9. a through hole;

31. an MEMS chip; 32. an ASIC chip;

41. a second sound cavity; 71. a first sound cavity.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

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, it need not be further defined or explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that are conventionally placed when the products of the present invention are used, and are used only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements to be referred to must have specific orientations, be constructed in specific orientations, and operate, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should also be noted that, unless otherwise explicitly stated or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being fixed or detachable or integrally connected; either mechanically or electrically. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In order to effectively reduce noise, reduce noise in the surrounding environment, and effectively improve the communication quality, the present embodiment provides a microphone structure, and details of the present embodiment are described in detail below with reference to fig. 1 to 7.

Example one

As shown in fig. 1, the microphone structure includes a hollow type case 1, a first substrate 2, an acoustic element 3, a second substrate 7, a third substrate 4, and an elastic vibration film 5. The microphone structure of the present embodiment utilizes bone conduction to transmit sound, and is attached to the outer skin of the human skeleton when in use.

The first substrate 2, the second substrate 7 and the third substrate 4 are laminated from top to bottom to form an integrated structure. The first substrate 2, the second substrate 7 and the third substrate 4 are all PCB circuit boards, and the first substrate 2, the second substrate 7 and the third substrate 4 are electrically connected with the lines of the RDL (Redistribution layer) layer through the through holes 9 by the through-silicon-via technology.

The hollow shell 1 is sealed and covered on the first substrate 2, the accommodating cavity 11 is formed between the hollow shell 1 and the first substrate 2, and the first substrate 2 is penetrated and provided with the sound transmission hole 21 along the thickness direction. The acoustic element 3 is disposed on the first substrate 2 and located in the accommodating chamber 11. The second substrate 7 is provided with a first acoustic chamber 71; the third substrate 4 is provided with a second sound cavity 41, and the sound transmission hole 21, the first sound cavity 71 and the second sound cavity 41 are coaxially arranged; the elastic diaphragm 5 is sealingly arranged at the transition between the first acoustic chamber 71 and the second acoustic chamber 41. The cross-sectional area of the second acoustic chamber 41 is smaller than the cross-sectional area of the first acoustic chamber 71 in this embodiment. The elastic vibration film 5 is disposed on the step between the first sound chamber 71 and the second sound chamber 41.

In short, the microphone structure provided by the present invention, the hollow casing 1 and the first substrate 2 are enclosed to form the accommodating cavity 11, the second substrate 7 and the third substrate 4 are hermetically disposed on the side of the first substrate 2 away from the hollow casing 1, and the first sound cavity 71, the second sound cavity 41 and the sound transmission hole 21 are coaxially disposed up and down. The acoustic element 3 is located in the accommodating cavity 11, the elastic vibration film 5 is hermetically arranged at the transition position of the first sound cavity 71 and the second sound cavity 41, the human skeleton is used for conducting sound signals, the third substrate 4 is abutted against the surface of the human skeleton, when vibration signals are conducted from the third substrate 4, the elastic vibration film 5 generates resonance after receiving the vibration signals, the vibration generated by the elastic vibration film 5 generates air pressure change in the cavity, and the air pressure signals caused by the vibration frequency and amplitude are sensed by the acoustic element. Because the bone conduction sound is used without arranging the sound inlet hole, the noise is effectively reduced, the noise of the surrounding environment is reduced, the conversation is clear, the tone quality is high-definition and has penetrating power, the influence of useless signals such as surrounding noise is reduced, the voice signal of a speaker is kept, and the conversation quality is effectively improved.

As shown in fig. 1 and fig. 6, the microphone structure further includes a fixing frame 8, one end surface of the fixing frame 8 is bonded with the elastic vibration film 5, and the other end surface of the fixing frame 8 is bonded with the third substrate 4. Through addding fixed frame 8, bond monoblock elastic vibration film 5 in the frame department of fixed frame 8 earlier, will bond elastic vibration film 5's fixed frame 8 again with glue and fix to third base plate 4 on, easily paste dress and the installation is firm.

Further, as shown in fig. 1, the microphone structure further includes a mass 6, and the mass 6 is disposed on the upper surface of the elastic vibration film 5 and located in the second sound cavity 41. The arrangement of the mass block 6 can make the vibration effect of the elastic vibration film 5 better, and the elastic vibration film is more sensitive to the input vibration signal, so that the elastic vibration film 5 can vibrate even if a tiny vibration signal is input. Specifically, the mass 6 is bonded to the elastic vibration film 5. In other embodiments, the mass 6 may be fixed to the elastic vibrating membrane 5 by other fixing methods without any limitation. The mass block 6 is made of metal or ceramic material. Reduce electromagnetic interference and is beneficial to further improving the tone quality.

In some application scenarios, as shown in fig. 4, the elastic vibration film 5 is a schematic structural diagram of an elastic soft film, and the elastic vibration film 5 is provided with an air vent 51 for adjusting air pressure in the first sound cavity 71 and the second sound cavity 41. Because the hollow shell 1 is hermetically connected with the first substrate 1, the upper surface of the elastic vibration film 5 is in a closed cavity state, and by additionally arranging the air holes 51, during vibration, gas molecules in the second sound cavity 41 enter the first sound cavity 71 through the air holes 51, so that the air pressures of the first sound cavity 71 and the second sound cavity 41 are balanced. The air holes 51 can adjust air pressure, so that the performance of the whole chip can be adjusted in a small range, and the sensitivity is improved. The elastic soft film is made of plastic.

In some application scenarios, as shown in fig. 5, the elastic vibration film 5 is a structural schematic diagram of an elastic metal sheet. The elastic metal sheet is made of metal steel or metal copper.

Further, as shown in fig. 1, the acoustic element 3 includes a MEMS chip 31 and an ASIC chip 32, the MEMS chip 31 and the ASIC chip 32 are connected by gold wires, the MEMS chip 31 is configured to receive the sound pressure signal from the sound transmission hole 21 and convert the sound pressure signal into an electrical signal, and the ASIC chip is configured to output the electrical signal after operational amplification. By adopting a gold thread, a circuit on the PCB and the through hole 9, the ASIC chip 32 and the MEMS chip 31 are electrically connected, and finally, the signals are output by a bonding pad below the third substrate 7, so that the transmission of the signals is realized.

Further, as shown in fig. 1, the MEMS chip 31 and the ASIC chip 32 are both adhered to the same side of the first substrate 2, and the MEMS chip 31 is disposed at the outlet of the sound transmission hole 21. The sound pressure signal can be directly received by the MEMS chip 31 after passing through the sound transmission hole 21, and the time for processing the sound is shortened. In this embodiment, the MEMS chip 31 and the ASIC chip 32 are both adhered to the first substrate 2 by glue and located in the accommodating cavity 11.

In other embodiments, the MEMS chip 31 and the ASIC chip 32 may be disposed on both upper and lower sides of the first substrate 2. Illustratively, the MEMS chip 31 is mounted on the upper surface of the first substrate 2, and the ASIC chip 32 is mounted on the lower surface of the first substrate 2 and located in the second cavity 41.

Further, as shown in fig. 1, the elastic vibration film 5 is a flat film. As shown in fig. 2 and 3, the outer edge of the flat membrane may be provided with a corrugation circumferentially, and the state that the elastic vibration membrane 5 floats with the sound signal is optimized by the action of the spring, so that the sound quality is further improved.

Further, the hollow shell 1 is made of metal. Utilize the metal to pass the sound characteristic, guarantee to hold the airtight effect of intracavity, improve the tone quality effect.

The present embodiment also provides a voice communication apparatus including the above-mentioned microphone structure. The voice communication equipment can be mobile phones, earphones and the like.

The specific working principle of the microphone structure of the embodiment is as follows: when the vibration signal is transmitted from the third substrate 4, the elastic vibration film 5 generates resonance after receiving the vibration signal, the vibration generated by the elastic vibration film 5 generates air pressure change in the cavity, the air pressure signal caused by the vibration frequency and amplitude is sensed by the high-sensitivity vibration film of the MEMS chip 31, the arrangement of the mass block 6 can make the vibration effect of the elastic vibration film 5 better, the vibration of the elastic vibration film can be caused even if the tiny vibration signal is transmitted, complete feedback and sound transmission are realized, and the distortion of sound is avoided.

Example two

Compared with the first embodiment, the basic structure of the microphone structure provided in this embodiment is the same as that of the first embodiment, and only the arrangement of the mass block 6 is different, and the description of the structure that is the same as that of the first embodiment is omitted in this embodiment.

As shown in fig. 7, the mass 6 of the present embodiment is bonded to the lower surface of the elastic vibration film 5 and is located in the second sound chamber 41.

In other implementations, the lower surface and the upper surface of the elastic vibration membrane 5 are both provided with masses 6.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A microphone structure, comprising:

a hollow-type housing (1);

a first substrate (2), a second substrate (7) and a third substrate (4) which are laminated in sequence from top to bottom;

the first substrate (2) is provided with a sound transmission hole (21) in a penetrating manner along the thickness direction; the second substrate (7) is provided with a first sound cavity (71); the third substrate (4) is provided with a second sound cavity (41), and the sound transmission hole (21), the first sound cavity (71) and the second sound cavity (41) are coaxially arranged;

the hollow shell (1) is arranged on the first substrate (2) in a sealing manner, the hollow shell (1) and the first substrate (2) are arranged in a surrounding manner to form an accommodating cavity (11), and the acoustic element (3) is arranged on the first substrate (2) and is positioned in the accommodating cavity (11);

and the elastic vibration film (5) is arranged at the transition of the first sound cavity (71) and the second sound cavity (72) in a sealing way.

2. The microphone structure according to claim 1, further comprising a fixing frame (8), wherein the elastic vibration film (5) is bonded to one end surface of the fixing frame (8), and the other end surface of the fixing frame (8) is bonded to the third substrate (4).

3. Microphone structure according to claim 1, characterized by the fact that it further comprises a mass (6), said mass (6) being glued to the upper surface of said elastic diaphragm (5) and being located inside said first acoustic chamber (71); or

The mass block (6) is adhered to the lower surface of the elastic vibration film (5) and is located in the second sound cavity (41).

4. Microphone structure according to claim 2, characterized by the fact that the elastic diaphragm (5) is provided with air vents (51) for adjusting the air pressure inside the first (71) and second (41) sound chambers.

5. The microphone structure as claimed in claim 2, wherein the acoustic element (3) comprises a MEMS chip (31) and an ASIC chip (32), the MEMS chip (31) and the ASIC chip (32) are connected by gold wires, the MEMS chip (31) is configured to receive a sound pressure signal from the sound transmission hole (21) and convert the sound pressure signal into an electrical signal, and the ASIC chip is configured to output the electrical signal after operational amplification.

6. Microphone structure according to claim 5, characterized in that the MEMS chip (31) and the ASIC chip (32) are both bonded to the same side of the first substrate (2), and the MEMS chip (31) is disposed at the outlet of the sound transmission hole (21).

7. Microphone structure according to claim 5, characterized by the fact that the elastic diaphragm (5) is a planar membrane.

8. Microphone structure according to claim 5, characterized by the fact that the first (2), second (7) and third (4) substrates are PCB circuit boards, the first (2), second (7) and third (4) substrates being electrically connected by vias (9).

9. Microphone structure according to claim 5, characterized by the fact that the hollow shell (1) is made of metal.

10. A voice communication device, characterized in that it comprises a microphone arrangement according to any of claims 1-9.