WO2023216687A1

WO2023216687A1 - Microphone structure and voice communication device

Info

Publication number: WO2023216687A1
Application number: PCT/CN2023/079600
Authority: WO
Inventors: 缪建民; 张金姣
Original assignee: 迈感微电子(上海)有限公司
Priority date: 2022-05-10
Filing date: 2023-03-03
Publication date: 2023-11-16

Abstract

The present application discloses a microphone structure and a voice communication device. The microphone structure comprises a hollow housing, a first substrate, an acoustic element, a second substrate, a third substrate and an elastic vibration thin film. The first substrate, the second substrate, and the third substrate are sequentially laminated from top to bottom. A sound transmission hole is formed in the first substrate in a penetrating manner in the thickness direction; a first sound cavity is formed in the second substrate; and a second sound cavity is formed in the third substrate, and the sound transmission hole, the first sound cavity, and the second sound cavity are coaxially arranged. The hollow housing sealingly covers the first substrate, an accommodating cavity is defined by the hollow housing and the first substrate, and the acoustic element is provided on the first substrate and located in the accommodating cavity. The elastic vibration thin film is sealedly provided at a transition position of the first sound cavity and the second sound cavity.

Description

Microphone structures and voice communication equipment

This application claims priority to Chinese patent applications with application numbers 202210505314.1 and 202221109905.9 submitted to the China Patent Office on May 10, 2022. The entire content of this application is incorporated into this application by reference.

Technical field

The present application relates to the field of microphone technology, for example, to a microphone structure and voice communication equipment.

Background technique

Micro-Electro-Mechanical System (MEMS) technology uses advanced semiconductor manufacturing processes to achieve mass manufacturing of sensors, actuators and other devices. The transmission method of traditional MEMS microphones is that the MEMS chip diaphragm receives airborne speech. The sound pressure signal passes through the sound inlet and is sensed by the high-sensitivity vibrating film of the MEMS chip, converting the sound signal into an electrical signal. An Application Specific Integrated Circuit (ASIC) chip electrically connected to the MEMS chip amplifies the signal and outputs it. The MEMS chip is a microcapacitor composed of a silicon diaphragm and a silicon back plate. It can convert changes in sound pressure into changes in capacitance, and then the ASIC chip converts the changes in capacitance into electrical signals to achieve "sound-to-electricity" conversion.

The sensor of a traditional MEMS microphone receives airborne speech. Airborne speech includes the voice of the caller and noise from the surroundings. When the noise is loud, the microphone will be interfered by noise, such as surrounding people, mechanical equipment, wind noise, etc. , seriously affecting call quality.

For this reason, there is an urgent need to provide a microphone structure and voice communication equipment to solve the above problems.

Contents of the invention

This application provides a microphone structure and voice communication equipment that can effectively reduce noise, reduce noise in the surrounding environment, and effectively improve call quality.

This application provides the following technical solutions:

A microphone structure including:

Hollow shell;

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

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

The hollow shell sealing cover is provided on the first substrate, the hollow shell and the first substrate are surrounded to form an accommodation cavity, and the acoustic element is provided on the first substrate and located in the accommodation cavity;

An elastic vibrating membrane is sealingly provided at the transition between the first sound cavity and the second sound cavity.

A voice communication device includes a technical solution of a microphone structure as described in any one of the above.

Description of the drawings

In order to illustrate the technical solutions in the embodiments of the present application, a brief introduction will be given below to the drawings required to be used in the description of the embodiments of the present application.

Figure 1 is a cross-sectional view of the microphone structure in Embodiment 1 of the present application;

Figure 2 is a first schematic diagram of the elastic vibration film with wrinkles in Embodiment 1 of the present application;

Figure 3 is a second schematic diagram of the elastic vibration film with wrinkles in Embodiment 1 of the present application;

Figure 4 is a schematic structural diagram of the elastic vibration film being an elastic soft film in Embodiment 1 of the present application;

Figure 5 is a schematic structural diagram of the elastic vibration film being an elastic metal sheet in Embodiment 1 of the present application;

Figure 6 is a schematic structural diagram of the fixed frame in Embodiment 2 of the present application;

Figure 7 is a cross-sectional view of the microphone structure in Embodiment 2 of the present application.

Reference signs:

1. Hollow shell; 11. Accommodation cavity; 2. First substrate; 21. Sound transmission hole; 3. Acoustic component; 4. Third substrate; 5. Elastic vibration membrane; 51. Breathing hole; 6. Mass block; 7. Second substrate; 8. Fixed frame; 9. Through hole;

31. MEMS chip; 32. ASIC chip;

41. The second tone cavity; 71. The first tone cavity.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. The described embodiments are some, but not all, of the embodiments of the present application. The components of the embodiments of the present application described and illustrated in the drawings may be arranged and designed in a variety of different configurations.

It should be noted that similar reference numerals and letters represent similar items in the following figures, therefore, once an item is defined in one figure, it does not need further definition or explanation in subsequent figures.

In the description of this application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or The positional relationship is based on the orientation or positional relationship shown in the attached drawing, or the orientation or positional relationship where the product is usually placed when used. It is only In order to facilitate the description of the present application and simplify the description, it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish descriptions and shall not be understood as indicating or implying relative importance. In the description of this application, unless otherwise stated, "plurality" means two or more.

In the description of this application, it should also be noted that, unless otherwise clearly stated and limited, the terms "setting" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection, or Integrally connected; can be mechanical or electrical. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood depending on the specific circumstances.

In this application, unless otherwise explicitly stated and limited, the term "above" or "below" a first feature on a second feature may include direct contact between the first and second features, or may also include the first and second features. Not in direct contact but through additional characteristic contact between them. Furthermore, the terms "above", "above" and "above" a first feature on a second feature include the first feature being directly above and diagonally above the second feature, or simply mean that the first feature is higher in level than the second feature. “Below”, “under” and “under” the first feature is the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature is less horizontally than the second feature.

The embodiments of the present application are described below. Examples of the embodiments are shown in the drawings, in which the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and cannot be understood as limiting the present application.

In order to effectively reduce noise, reduce noise in the surrounding environment, and effectively improve call quality, this embodiment provides a microphone structure. The specific contents of this embodiment will be described below with reference to FIGS. 1 to 7 .

Embodiment 1

As shown in Figure 1, the microphone structure includes a hollow housing 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 this embodiment uses bone conduction for sound transmission, and is attached to the outer skin of human bones during use.

The first substrate 2, the second substrate 7 and the third substrate 4 are an integrated structure laminated sequentially from top to bottom. The first substrate 2, the second substrate 7 and the third substrate 4 are all printed circuit boards (PCB). Through through-silicon via technology, the first substrate 2, the second substrate 7 and the third substrate 4 is electrically connected through the through hole 9 and the lines of the redistribution layer (RDL). Optionally, the first substrate 2 , the second substrate 7 and the third substrate 4 are electrically connected through the through hole 9 .

The sealing cover of the hollow housing 1 is provided on the first substrate 2. A receiving cavity 11 is formed between the hollow housing 1 and the first substrate 2. The first substrate 2 is provided with a sound transmission hole 21 through the thickness direction. Acoustic components 3 It is provided on the first substrate 2 and located in the containing cavity 11 . The second substrate 7 is provided with a first sound cavity 71; the third substrate 4 is provided with a second sound cavity 41; the sound transmission hole 21, the first sound cavity 71 and the second sound cavity 41 are coaxially arranged; the elastic vibration membrane 5 is provided with a seal At the transition between the first sound cavity 71 and the second sound cavity 41 . In this embodiment, the cross-sectional area of the second sound cavity 41 is smaller than the cross-sectional area of the first sound cavity 71 . The elastic vibration membrane 5 is provided on the step between the first sound cavity 71 and the second sound cavity 41 .

In the microphone structure provided by this application, a receiving cavity 11 is formed between the hollow housing 1 and the first substrate 2 , and a second substrate 7 and a third substrate are sealingly provided on the side of the first substrate 2 away from the hollow housing 1 4. The first sound cavity 71, the second sound cavity 41 and the sound transmission hole 21 are arranged coaxially up and down. The acoustic element 3 is located in the accommodating cavity 11 , and an elastic vibration membrane 5 is sealingly provided at the transition between the first sound cavity 71 and the second sound cavity 41 . The microphone structure provided in this application uses human bones to conduct sound signals, and the third substrate 4 is pressed against the surface of the human bones. When the vibration signal is transmitted from the third substrate 4, the elastic vibration film 5 receives the vibration signal. Resonance is generated, and the vibration generated by the elastic vibration membrane 5 causes air pressure changes in the cavity. The air pressure signal caused by the vibration frequency and amplitude is sensed by the acoustic element 3 . Since there is no need to set up a sound inlet, bone conduction sound is used to effectively reduce noise and reduce the noise in the surrounding environment, making the call clear, high-definition and penetrating, reducing the influence of useless signals such as surrounding noise, while preserving the call Human voice signals effectively improve call quality.

As shown in FIG. 1 combined with FIG. 6 , the microphone structure also includes a fixed frame 8 , the first end surface of the fixed frame 8 is bonded with the elastic vibration film 5 , and the second end surface of the fixed frame 8 is bonded to the third substrate 4 . By adding a fixed frame 8, the entire elastic vibration film 5 is first bonded to the frame of the fixed frame 8, and then the fixed frame 8 with the elastic vibration film 5 bonded is fixed to the third substrate 4 with glue, which is easy to mount. And the installation is stable.

As shown in FIG. 1 , the microphone structure also includes a mass block 6 , which is disposed on the upper surface of the elastic vibration film 5 and located in the first sound cavity 71 . The setting of the mass block 6 can make the elastic vibration membrane 5 have a better vibration effect and be more sensitive to incoming vibration signals. Even a small vibration signal can cause the elastic vibration membrane 5 to vibrate. As an example, the mass block 6 is bonded to the elastic vibration film 5 . In other embodiments, other fixing methods can also be used to fix the mass block 6 on the elastic vibration membrane 5, without excessive restrictions here. The mass block 6 is made of metal or ceramic material, which can reduce electromagnetic interference and help further improve the sound quality.

In some application scenarios, as shown in Figure 4, Figure 4 is a schematic structural diagram in which the elastic vibration film 5 is an elastic soft film. The elastic vibration film 5 is provided with ventilation holes 51, and the ventilation holes 51 are arranged to adjust the first sound cavity 71 and The air pressure in the second sound cavity 41. Since the hollow shell 1 is sealedly connected to the first substrate 2, the elastic vibration membrane 5 is in a sealed cavity state. By adding the ventilation holes 51, when vibrating, the gas molecules in the second sound cavity 41 enter through the ventilation holes 51. In the first sound cavity 71 , the air pressures of the first sound cavity 71 and the second sound cavity 41 are balanced. The ventilation hole 51 can adjust the air pressure, thereby adjusting the performance of the entire chip within a small range and improving the sensitivity. The elastic soft membrane is made of plastic.

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

As shown in Figure 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 using gold wires. The MEMS chip 31 is configured to receive the sound pressure signal from the sound transmission hole 21 and transmit the sound pressure signal Converted into electrical signals, the ASIC chip is set to amplify the electrical signals and output them. The electrical connection between the ASIC chip 32 and the MEMS chip 31 is realized through gold wires. After the MEMS chip 31 converts the sound pressure signal into an electrical signal, the electrical signal is transmitted to the ASIC chip 32. The ASIC chip 32 amplifies the electrical signal and outputs it. The signal passes through the through hole and is finally output from the pad below the third substrate (PCB board) 7 to realize signal transmission.

As shown in Figure 1, 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 exit of the sound transmission hole 21, so that the sound pressure signal can pass through the sound transmission hole 21. It is directly received by the MEMS chip 31, shortening the time for processing sound. In this embodiment, the MEMS chip 31 and the ASIC chip 32 are both bonded to the first substrate 2 using glue, and the MEMS chip 31 and the ASIC chip 32 are located in the accommodation cavity 11 .

In other embodiments, the MEMS chip 31 and the ASIC chip 32 may also be disposed on the upper and lower sides of the first substrate 2 . For example, the MEMS chip 31 is installed on the upper surface of the first substrate 2 , and the ASIC chip 32 is installed on the lower surface of the first substrate 2 and is located in the first sound cavity 71 .

As shown in Figure 1, the elastic vibration film 5 is a flat film. As shown in Figures 2 and 3, folds can also be set circumferentially on the outer edge of the flat membrane to optimize the floating state of the elastic vibrating membrane 5 with the sound signal by referring to the function of the spring, further improving the sound quality.

The hollow shell 1 is made of metal material. The sound transmission characteristics of metal are used to ensure the sealing effect in the accommodation cavity 11 and improve the sound quality effect.

This embodiment also provides a voice communication device, which includes the above-mentioned microphone structure. Voice communication equipment can be mobile phones, headphones and other equipment.

The working principle of the microphone structure of this embodiment is as follows: when a vibration signal is transmitted from the third substrate 4, the elastic vibration film 5 resonates after receiving the vibration signal. The vibration generated by the elastic vibration film 5 causes air pressure changes in the cavity, and as the vibration signal is transmitted, the elastic vibration film 5 resonates. 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 setting of the mass block 6 can make the vibration effect of the elastic vibration film 5 better. Even a small vibration signal can cause the vibration of the elastic film. , complete feedback and transmission of sound, avoiding sound distortion.

Embodiment 2

This embodiment provides a microphone structure. Compared with Embodiment 1, the basic structure of the microphone structure provided by this embodiment is the same as Embodiment 1. Only the arrangement of the mass block 6 is different. This embodiment does not The structure that is the same as that of Embodiment 1 will be described again.

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

In other implementations, the mass block 6 is provided on both the lower surface and the upper surface of the elastic vibration membrane 5 .

Claims

A microphone structure including:

Hollow shell(1);

The first substrate (2), the second substrate (7) and the third substrate (4) are stacked sequentially from top to bottom;

The first substrate (2) is provided with a sound transmission hole (21) along the thickness direction; the second substrate (7) is provided with a first sound cavity (71); and the third substrate (4) is provided with a third sound cavity (71). Two sound chambers (41), the sound transmission hole (21), the first sound chamber (71) and the second sound chamber (41) are coaxially arranged;

The sealing cover of the hollow shell (1) is provided on the first substrate (2), and the hollow shell (1) and the first substrate (2) are surrounded to form an accommodation cavity (11), and the acoustic element (3) It is provided on the first substrate (2) and located in the accommodation cavity (11);

The elastic vibrating membrane (5) is sealed and arranged at the transition between the first sound cavity (71) and the second sound cavity (41).
The microphone structure according to claim 1, further comprising a fixed frame (8), the first end surface of the fixed frame (8) is bonded with the elastic vibration film (5), and the third end surface of the fixed frame (8) is bonded with the elastic vibration film (5). The two end surfaces are bonded to the third substrate (4).
The microphone structure according to claim 1, further comprising a mass block (6) bonded to the upper surface of the elastic vibration film (5) and located in the first sound cavity (71) within; or

The mass block (6) is bonded to the lower surface of the elastic vibration film (5) and is located in the second sound cavity (41).
The microphone structure according to claim 2, wherein the elastic vibration film (5) is provided with a ventilation hole (51), and the ventilation hole (51) is configured to adjust the first sound cavity (71) and the Describe the air pressure in the second sound cavity (41).
The microphone structure according to claim 2, wherein the acoustic element (3) includes a micro Electromechanical system MEMS chip (31) and application-specific integrated circuit ASIC chip (32). The MEMS chip (31) and the ASIC chip (32) are connected using gold wires. The MEMS chip (31) is configured to accept data from the The sound pressure signal of the sound transmission hole (21) is converted into an electrical signal, and the ASIC chip is configured to amplify the electrical signal and output it.
The microphone structure according to claim 5, wherein 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 arranged at the exit of the sound transmission hole (21).
The microphone structure according to claim 5, wherein the elastic vibration film (5) is a planar film.
The microphone structure according to claim 5, wherein the first substrate (2), the second substrate (7) and the third substrate (4) are all printed circuit boards (PCBs), and the first The substrate (2), the second substrate (7) and the third substrate (4) are electrically connected through a through hole (9).
The microphone structure according to claim 5, wherein the hollow housing (1) is made of metal.
A voice communication device, including the microphone structure according to any one of claims 1-9.