阅读说明：本技术 硅基麦克风装置及电子设备 (Silicon-based microphone device and electronic equipment ) 是由 王云龙 吴广华 蓝星烁 于 2020-06-09 设计创作，主要内容包括：本申请实施例提供了一种硅基麦克风装置及电子设备。该硅基麦克风装置包括：电路板,开设有至少两个进声孔；屏蔽外壳,罩合在电路板的一侧；偶数个差分式硅基麦克风芯片,都位于声腔内；每两个差分式硅基麦克风芯片中,一个差分式硅基麦克风芯片的第一麦克风结构,与另一个差分式硅基麦克风芯片的第二麦克风结构电连接,一个差分式硅基麦克风芯片的第二麦克风结构,与另一个差分式硅基麦克风芯片的第一麦克风结构电连接；安装板,开设有至少一个开孔,开孔与部分进声孔连通。本申请实施例实现了削弱或抵消电子设备自身噪音,提高了输出的音频信号的质量。(The embodiment of the application provides a silicon-based microphone device and electronic equipment. The silicon-based microphone device includes: the circuit board is provided with at least two sound inlet holes; a shield case covering one side of the circuit board; the even number of differential silicon-based microphone chips are positioned in the sound cavity; in every two differential silicon-based microphone chips, the first microphone structure of one differential silicon-based microphone chip is electrically connected with the second microphone structure of the other differential silicon-based microphone chip, and the second microphone structure of one differential silicon-based microphone chip is electrically connected with the first microphone structure of the other differential silicon-based microphone chip; the mounting plate is provided with at least one opening, and the opening is communicated with part of the sound inlet holes. The embodiment of the application weakens or offsets the noise of the electronic equipment, and improves the quality of the output audio signal.)

1. A silicon-based microphone apparatus, comprising:

the circuit board is provided with at least two sound inlet holes;

the shielding shell covers one side of the circuit board and forms an acoustic cavity with the circuit board;

the even number of differential silicon-based microphone chips are positioned in the sound cavity; the differential silicon-based microphone chips are arranged at the sound inlet holes in a one-to-one correspondence manner, and the back cavity of each differential silicon-based microphone chip is communicated with the corresponding sound inlet hole; in every two differential silicon-based microphone chips, the first microphone structure of one differential silicon-based microphone chip is electrically connected with the second microphone structure of the other differential silicon-based microphone chip, and the second microphone structure of one differential silicon-based microphone chip is electrically connected with the first microphone structure of the other differential silicon-based microphone chip;

the mounting panel, set up in the circuit board is kept away from one side of shielding shell, at least one trompil has been seted up to the mounting panel, trompil and part the sound inlet hole intercommunication.

2. The silicon-based microphone device as defined by claim 1 wherein the portion of the sound inlet holes communicating with the opening correspondingly communicates with the back cavity of one of each two differential silicon-based microphone chips.

3. The silicon-based microphone device as claimed in claim 1 or 2, wherein the differential silicon-based microphone chip further comprises an upper back plate, a semiconductor diaphragm and a lower back plate which are stacked and spaced apart;

the upper back plate and the semiconductor diaphragm form a main body of the first microphone structure; the semiconductor diaphragm and the lower back plate form a main body of the second microphone structure;

the upper back plate and the lower back plate are respectively provided with a plurality of airflow holes corresponding to the sound inlet holes.

4. The silicon-based microphone device of claim 3, wherein each two differential silicon-based microphone chips comprise a first differential silicon-based microphone chip and a second differential silicon-based microphone chip;

the first upper back plate of the first differential silicon-based microphone chip is electrically connected with the second lower back plate of the second differential silicon-based microphone chip and is used for forming a first path of signal;

and the first lower back plate of the first differential type silicon-based microphone chip is electrically connected with the second upper back plate of the second differential type silicon-based microphone chip and is used for forming a second path of signals.

5. The silicon-based microphone device of claim 4, wherein the first semiconductor diaphragm of the first differential silicon-based microphone chip is electrically connected to the second semiconductor diaphragm of the second differential silicon-based microphone chip, and at least one of the first semiconductor diaphragm and the second semiconductor diaphragm is configured to be electrically connected to a constant voltage source.

6. The silicon-based microphone device of claim 5, further comprising a control chip;

the control chip is positioned in the sound cavity and is electrically connected with the circuit board;

one of the first upper back plate and the second lower back plate is electrically connected with one signal input end of the control chip; one of the first lower back plate and the second upper back plate is electrically connected with the other signal input end of the control chip.

7. The silicon-based microphone device of claim 3, wherein the differential silicon-based microphone chip comprises a silicon substrate;

the first microphone structure and the second microphone structure are arranged on one side of the silicon substrate in a laminated mode;

the silicon substrate is provided with a through hole used for forming the back cavity, and the through hole corresponds to the first microphone structure and the second microphone structure; one side of the silicon substrate, which is far away from the first microphone structure and the second microphone structure, is fixedly connected with the circuit board, and the through hole is communicated with the sound inlet hole.

8. The silicon-based microphone device of claim 7, wherein the differential silicon-based microphone chip further comprises patterned: a first insulating layer, a second insulating layer and a third insulating layer;

the silicon substrate, the first insulating layer, the lower back plate, the second insulating layer, the semiconductor diaphragm, the third insulating layer and the upper back plate are sequentially stacked.

9. The silicon-based microphone device of claim 1, further comprising: a first connection ring and a second connection ring;

the first connecting ring is connected between the opening of the mounting plate and part of the sound inlet holes of the circuit board, so that an airtight sound channel is formed between the opening and part of the sound inlet holes;

the second connecting ring is connected between the rest of the sound inlet holes of the circuit board and the mounting plate, so that a closed cavity is formed between the rest of the sound inlet holes and the mounting plate.

10. The silicon-based microphone device according to claim 1, wherein the silicon-based microphone device has any one or more of the following characteristics:

the differential silicon-based microphone chip is fixedly connected with the circuit board through silica gel;

the shielding shell comprises a metal shell which is electrically connected with the circuit board;

the shielding shell is fixedly connected with one side of the circuit board through solder paste or conductive adhesive;

the circuit board comprises a printed circuit board.

11. An electronic device, comprising: a silicon-based microphone arrangement as claimed in any one of claims 1-10.

12. The electronic device of claim 11, wherein the mounting board in the silicon-based microphone apparatus is a main board of the electronic device.

Technical Field

The application relates to the technical field of sound-electricity conversion, in particular to a silicon-based microphone device and electronic equipment.

Background

With the development of wireless communication, more and more terminal users such as mobile phones are available. The user's requirement for the mobile phone is not only satisfied with the call but also to provide a high quality call effect, especially the development of the current mobile multimedia technology, the call quality of the mobile phone is more important, and the design of the microphone of the mobile phone as the voice pickup device of the mobile phone directly affects the call quality. The microphones that are used more frequently at present include conventional electret microphones and silicon-based microphones.

When the existing silicon-based microphone acquires a sound signal, a silicon-based microphone chip in the microphone generates vibration under the action of the acquired sound wave, and the vibration brings about capacitance change which can form an electric signal, so that the sound wave is converted into the electric signal to be output. However, the conventional microphone does not deal with noise satisfactorily, and the quality of an output audio signal is affected.

Disclosure of Invention

The application aims at the defects of the prior art and provides a silicon-based microphone device and electronic equipment, which are used for solving the technical problems that the prior microphone is not ideal in noise processing and affects the quality of output audio signals in the prior art.

In a first aspect, an embodiment of the present application provides a silicon-based microphone apparatus, including:

the circuit board is provided with at least two sound inlet holes;

the shielding shell covers one side of the circuit board and forms an acoustic cavity with the circuit board;

the even number of differential silicon-based microphone chips are positioned in the sound cavity; the differential silicon-based microphone chips are arranged at the sound inlet holes in a one-to-one correspondence manner, and the back cavity of each differential silicon-based microphone chip is communicated with the corresponding sound inlet hole; in every two differential silicon-based microphone chips, the first microphone structure of one differential silicon-based microphone chip is electrically connected with the second microphone structure of the other differential silicon-based microphone chip, and the second microphone structure of one differential silicon-based microphone chip is electrically connected with the first microphone structure of the other differential silicon-based microphone chip;

the mounting panel sets up in the one side that shielding shell was kept away from to the circuit board, and at least one trompil has been seted up to the mounting panel, trompil and partial sound inlet hole intercommunication.

In a second aspect, an embodiment of the present application provides an electronic device, including: the silicon-based microphone apparatus as provided in the first aspect.

The technical scheme provided by the embodiment of the application has the following beneficial technical effects: an even number of differential silicon-based microphone chips are adopted for sound-electricity conversion, in every two differential silicon-based microphone chips, a back cavity of one differential silicon-based microphone chip is communicated with the outside through a sound inlet hole on a circuit board and an opening hole on an installation plate, so that external sound waves and the noise of electronic equipment can act on the differential silicon-based microphone chips, and the differential silicon-based microphone chips generate mixed electric signals of sound electric signals and noise electric signals;

the back cavity of the other differential silicon-based microphone chip is communicated with the sound inlet hole on the circuit board and is sealed by the mounting plate, so that most external sound waves can be prevented from entering, the noise of the electronic equipment can act on the differential silicon-based microphone chip, and the differential silicon-based microphone chip generates a noise electric signal;

because the first microphone structure and the second microphone structure in the differential silicon-based microphone chips respectively generate electric signals with the same variation amplitude and opposite sign under the action of sound waves, in each two differential silicon-based microphone chips, the first microphone structure of one differential silicon-based microphone chip is electrically connected with the second microphone structure of the other differential silicon-based microphone chip, the second microphone structure of one differential silicon-based microphone chip is electrically connected with the first microphone structure of the other differential silicon-based microphone chip, the mixed electric signal of the sound electric signal and the noise electric signal generated by one differential silicon-based microphone chip can be superposed with the noise electric signal with the same variation amplitude and opposite sign generated by the other differential silicon-based microphone chip, so that the homologous noise signals in the mixed electric signal can be weakened or counteracted, thereby improving the quality of the audio signal.

Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

Drawings

The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic diagram illustrating an internal structure of a silicon-based microphone device according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a mounting plate and a connection ring in a silicon-based microphone device according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a single differential silicon-based microphone chip in a silicon-based microphone device according to an embodiment of the present disclosure;

fig. 4 is a schematic connection diagram of two differential silicon-based microphone chips in a silicon-based microphone device according to an embodiment of the present disclosure.

In the figure:

100-a circuit board; 110 a-first sound inlet hole; 110 b-a second sound inlet aperture;

200-a shielded enclosure; 210-an acoustic cavity;

300-differential silicon-based microphone chip; 300 a-a first differential silicon-based microphone chip; 300 b-a second differential silicon-based microphone chip;

301-a first microphone structure; 301 a-a first microphone structure of a first differential silicon-based microphone chip; 301 b-a first microphone structure of a second differential silicon-based microphone chip;

302-a second microphone structure; 302 a-a second microphone structure of the first differential silicon-based microphone chip; 302 b-a second microphone structure of a second differential silicon-based microphone chip;

303-the back cavity; 303 a-a back cavity of the first differential silicon-based microphone chip; 303 b-a back cavity of the second differential silicon-based microphone chip;

310-upper back plate; 310 a-a first upper back plate; 310 b-a second upper back plate;

311 — upper airflow aperture;

312 — an upper back plate electrode; 312a — an upper back plate electrode of the first upper back plate; 312 b-an upper back plate electrode of the second upper back plate;

313 — upper air gap;

320-lower back plate; 320 a-first lower back plate; 320 b-a second lower back plate;

321-lower airflow aperture;

322-lower back plate electrode; 322 a-the lower back plate electrode of the first lower back plate; 322 b-a lower back plate electrode of a second lower back plate;

323-lower air gap;

330-a semiconductor diaphragm; 330 a-a first semiconductor diaphragm; 330 b-a second semiconductor diaphragm;

331-semiconductor diaphragm electrodes; 331 a-a semiconductor diaphragm electrode of the first semiconductor diaphragm; 331 b-a semiconductor diaphragm electrode of the second semiconductor diaphragm;

340-a silicon substrate; 340 a-a first silicon substrate; 340 b-a second silicon substrate;

341-a through hole;

350 — a first insulating layer;

360-a second insulating layer;

370-a third insulating layer;

380-wire;

400-control chip;

500-mounting a plate; 510-opening a hole;

610-a first connecting ring; 620-second connecting ring.

Detailed Description

Reference will now be made in detail to the present application, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar parts or parts having the same or similar functions throughout. In addition, if a detailed description of the known art is not necessary for illustrating the features of the present application, it is omitted. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

It will be understood by those within the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or wirelessly coupled. As used herein, the term "and/or" includes all or any element and all combinations of one or more of the associated listed items.

The inventor of The present application has studied and found that, with The popularization of IOT (The Internet of Things) devices such as smart speakers, it is not easy for a user to use a voice command for a smart device that is generating sound, for example: when a voice instruction such as interruption and awakening is given to a functional loudspeaker box playing music, or a hand-free mode (hand-free operation) of a mobile phone is used for communication. Often, a user needs to approach the IOT device as close as possible, interrupt the playing music with a dedicated wake-up word, and then perform human-computer interaction. In these typical voice interaction scenarios, echo cancellation is not effective because the IOT device is in use, because it is playing music or sounding through a speaker, causing vibrations in the body that are picked up by a microphone on the IOT device. This phenomenon is particularly obvious in smart home products with large vibration, such as mobile phones playing music, TWS (True Wireless Stereo) earphones, floor sweeping robots, smart air conditioners, smart range hoods and the like.

The application provides a silicon-based microphone device and electronic equipment, aims at solving the technical problems in the prior art.

The following describes the technical solutions of the present application and how to solve the above technical problems with specific embodiments.

An embodiment of the present application provides a silicon-based microphone device, and a schematic structural diagram of the silicon-based microphone device is shown in fig. 1 and fig. 2, and includes: circuit board 100, shield case 200, an even number of differential silicon-based microphone chips 300, and mounting board 500.

The circuit board 100 is provided with at least two sound inlets.

The shield case 200 is covered on one side of the circuit board 100 to form an acoustic cavity 210 with the circuit board 100.

An even number of differential silicon-based microphone chips 300 are all located within the acoustic cavity 210. The differential silicon-based microphone chips 300 are correspondingly arranged at the sound inlet holes one by one, and the back cavity 303 of each differential silicon-based microphone chip 300 is communicated with the corresponding sound inlet hole. In every two differential silicon-based microphone chips 300, the first microphone structure 301 of one differential silicon-based microphone chip 300 is electrically connected to the second microphone structure 302 of the other differential silicon-based microphone chip 300, and the second microphone structure 302 of one differential silicon-based microphone chip 300 is electrically connected to the first microphone structure 301 of the other differential silicon-based microphone chip 300.

The mounting plate 500 is disposed on a side of the circuit board 100 away from the shielding shell 200, the mounting plate 500 defines at least one opening 510, and the opening 510 is communicated with a portion of the sound inlet.

In this embodiment, an even number of differential silicon-based microphone chips 300 are used for performing the sound-electricity conversion, and it should be noted that the silicon-based microphone device in fig. 1 is only exemplified by two differential silicon-based microphone chips 300.

In some possible embodiments, the part of the sound inlet hole communicating with the opening 510 is communicated with the back cavity 303 of one of each two differential silicon-based microphone chips 300. That is, in every two differential silicon-based microphone chips 300, the back cavity 303 of one differential silicon-based microphone chip 300 is communicated with the outside through the sound inlet hole on the circuit board 100 and the opening 510 on the mounting plate 500, and the back cavity 303 of the other differential silicon-based microphone chip 300 is communicated with the sound inlet hole on the circuit board 100 and is sealed by the mounting plate 500.

Specifically, the back cavity 303a of the first differential silicon-based microphone chip 300a is communicated with the outside through the first sound inlet 110a on the circuit board 100 and the opening 510 on the mounting plate 500, so that both the external sound wave and the noise of the electronic device can act on the first differential silicon-based microphone chip 300a, and the first differential silicon-based microphone chip 300a generates a mixed electrical signal of the sound electrical signal and the noise electrical signal.

The back cavity 303b of the second differential silicon-based microphone chip 300b is communicated with the second sound inlet 110b on the circuit board 100 and is sealed by the mounting plate 500, so that most external sound waves can be prevented from entering, the noise of the electronic device can act on the second differential silicon-based microphone chip 300b, and the second differential silicon-based microphone chip 300b generates a noise electrical signal.

For convenience of description, one microphone structure on a side of the differential silicon-based microphone chip 300 away from the circuit board 100 is defined as a first microphone structure 301, and one microphone structure on a side of the differential silicon-based microphone chip 300 close to the circuit board 100 is defined as a second microphone structure 302.

Because the first microphone structure 301 and the second microphone structure 302 in the differential silicon-based microphone chip 300 respectively generate electrical signals with the same variation amplitude and opposite sign under the action of sound waves, in the embodiment of the present application, the first microphone structure 301a of the first differential silicon-based microphone chip 300a is electrically connected to the second microphone structure 302b of the second differential silicon-based microphone chip 300b, the second microphone structure 302a of the first differential silicon-based microphone chip 300a is electrically connected to the first microphone structure 301b of the second differential silicon-based microphone chip 300b, so that the mixed electrical signal of the sound electrical signal and the noise electrical signal generated by the first differential silicon-based microphone chip 300a can be superimposed with the noise electrical signal with the same variation amplitude and opposite sign generated by the second differential silicon-based microphone chip 300b, thereby attenuating or canceling the homologous noise signals in the mixed electrical signal and further improving the quality of the audio signal.

Alternatively, the differential silicon-based microphone chip 300 is fixedly connected to the circuit board 100 through silicon gel.

The shielding shell 200 and the circuit board 100 enclose a relatively closed acoustic cavity 210. In order to shield the differential silicon-based microphone chip 300 and other devices in the acoustic cavity 210 from electromagnetic interference, the shielding case 200 may optionally include a metal case, and the metal case is electrically connected to the circuit board 100.

Optionally, the shielding shell 200 is fixedly attached to one side of the circuit board 100 by solder paste or conductive paste.

Alternatively, the Circuit Board 100 includes a PCB (Printed Circuit Board 100) Board.

In some possible embodiments, as shown in fig. 3, the differential silicon-based microphone chip 300 further includes an upper back plate 310, a semiconductor diaphragm 330, and a lower back plate 320, which are stacked and spaced apart. Specifically, gaps, such as air gaps, are provided between the upper back plate 310 and the semiconductor diaphragm 330, and between the semiconductor diaphragm 330 and the lower back plate 320.

The upper backplate 310 and the semiconductor diaphragm 330 constitute the body of the first microphone structure 301. The semiconductor diaphragm 330 and the lower backplate 320 form the body of the second microphone structure 302.

The upper back plate 310 and the lower back plate 320 are provided with a plurality of airflow holes at portions corresponding to the sound inlet holes, respectively.

For convenience of description, one of the back plates of the differential silicon-based microphone chip 300 on the side away from the circuit board 100 is referred to as an upper back plate 310, and one of the back plates of the differential silicon-based microphone chip 300 on the side close to the circuit board 100 is referred to as a lower back plate 320.

In this embodiment, the semiconductor diaphragm 330 is shared by the first microphone structure 301 and the second microphone structure 302. The semiconductor diaphragm 330 may adopt a thin and flexible structure, and may be bent and deformed under the action of sound waves; the upper back plate 310 and the lower back plate 320 may both have a structure that is much thicker than the semiconductor diaphragm 330 and has a stronger rigidity, and are not easily deformed.

In particular, the semiconductor diaphragm 330 may be arranged parallel to the upper backplate 310 and separated by an upper air gap 313, thereby forming the body of the first microphone structure 301; a semiconductor diaphragm 330 may be arranged parallel to the lower backplate 320 and separated by a lower air gap 323, forming the body of the second microphone structure 302. It is understood that the electric fields are formed (non-conduction) between the semiconductor diaphragm 330 and the upper back plate 310 and between the semiconductor diaphragm 330 and the lower back plate 320. The sound waves entering from the sound inlet holes can contact with the semiconductor diaphragm 330 through the back cavity 303 and the lower airflow hole 321 on the lower back plate 320.

When sound waves enter the back cavity 303 of the differential silicon-based microphone chip 300, the semiconductor diaphragm 330 is deformed under the action of the sound waves, and the deformation causes changes in the gaps between the semiconductor diaphragm 330 and the upper back plate 310 and between the semiconductor diaphragm 330 and the lower back plate 320, which brings changes in the capacitance between the semiconductor diaphragm 330 and the upper back plate 310 and changes in the capacitance between the semiconductor diaphragm 330 and the lower back plate 320, that is, the sound waves are converted into electrical signals.

For a single differential silicon-based microphone chip 300, an upper electric field is formed in the gap between the semiconductor diaphragm 330 and the upper back plate 310 by applying a bias voltage between the semiconductor diaphragm 330 and the upper back plate 310. Similarly, by applying a bias voltage between the semiconductor diaphragm 330 and the lower back plate 320, a lower electric field is formed in the gap between the semiconductor diaphragm 330 and the lower back plate 320. Since the polarities of the upper electric field and the lower electric field are opposite, when the semiconductor diaphragm 330 is bent up and down by the action of the sound wave, the capacitance variation of the first microphone structure 301 and the capacitance variation of the second microphone structure 302 have the same magnitude and opposite signs.

Optionally, the semiconductor diaphragm 330 may be made of polysilicon material, and the thickness of the semiconductor diaphragm 330 is not greater than 1 μm, and the semiconductor diaphragm may also deform under the action of a small sound wave, so that the sensitivity is high; the upper back plate 310 and the lower back plate 320 may be made of a material having relatively high rigidity and a thickness of several micrometers, and a plurality of upper airflow holes 311 are etched in the upper back plate 310 and a plurality of lower airflow holes 321 are etched in the lower back plate 320. Therefore, when the semiconductor diaphragm 330 is deformed by the sound wave, neither the upper back plate 310 nor the lower back plate 320 is affected to deform.

Alternatively, the gap between the semiconductor diaphragm 330 and the upper back plate 310 or the lower back plate 320 is several micrometers, i.e., micrometers, respectively.

In some possible embodiments, as shown in fig. 4, each two differential silicon-based microphone chips 300 includes a first differential silicon-based microphone chip 300a and a second differential silicon-based microphone chip 300 b.

The first upper back plate 310a of the first differential silicon-based microphone chip 300a is electrically connected to the second lower back plate 320b of the second differential silicon-based microphone chip 300b for forming a first signal.

The first lower back plate 320a of the first differential silicon-based microphone chip 300a is electrically connected to the second upper back plate 310b of the second differential silicon-based microphone chip 300b for forming a second path of signals.

As described in detail above, in a single differential silicon-based microphone chip 300, the capacitance variation of the first microphone structure 301 has the same magnitude and opposite sign as the capacitance variation of the second microphone structure 302, and similarly, in every two differential silicon-based microphone chips 300, the capacitance variation at the upper back plate 310 of one differential silicon-based microphone chip 300 and the capacitance variation at the lower back plate 320 of the other differential silicon-based microphone chip 300 have the same magnitude and opposite sign.

Therefore, in this embodiment, the first path of signal obtained by superimposing the mixed electrical signal of the sound electrical signal and the noise electrical signal generated at the first upper back plate 310a of the first differential silicon-based microphone chip 300a and the noise electrical signal generated at the second lower back plate 320b of the second differential silicon-based microphone chip 300b can weaken or cancel the homologous noise signal in the mixed electrical signal, thereby improving the quality of the first path of signal.

Similarly, the second path of signal obtained by superimposing the mixed electrical signal of the acoustic electrical signal and the noise electrical signal generated at the first lower back plate 320a of the first differential silicon-based microphone chip 300a and the noise electrical signal generated at the second upper back plate 310b of the second differential silicon-based microphone chip 300b can weaken or cancel the homologous noise signal in the mixed electrical signal, thereby improving the quality of the second path of signal.

Specifically, the upper back plate electrode 312a of the first upper back plate 310a and the lower back plate electrode 322b of the second lower back plate 320b may be electrically connected through a wire 380 to form a first path of signal; the lower back plate electrode 322a of the first lower back plate 320a and the upper back plate electrode 312b of the second upper back plate 310b may be electrically connected through a wire 380 for forming a second path of signal.

In some possible embodiments, as shown in fig. 4, the first semiconductor diaphragm 330a of the first differential silicon-based microphone chip 300a is electrically connected to the second semiconductor diaphragm 330b of the second differential silicon-based microphone chip 300b, and at least one of the first semiconductor diaphragm 330a and the second semiconductor diaphragm 330b is used to be electrically connected to a constant voltage source.

In this embodiment, the first semiconductor diaphragm 330a of the first differential silicon-based microphone chip 300a is electrically connected to the second semiconductor diaphragm 330b of the second differential silicon-based microphone chip 300b, so that the semiconductor diaphragms 330 of the two differential silicon-based microphone chips 300 have the same potential, that is, the two differential silicon-based microphone chips 300 can be unified to generate the reference of the electrical signal.

Specifically, the semiconductor diaphragm electrode 331a of the first semiconductor diaphragm 330a and the semiconductor diaphragm electrode 331b of the second semiconductor diaphragm 330b may be electrically connected through a wire 380, respectively.

Alternatively, the semiconductor diaphragms 330 of all the differential silicon-based microphone chips 300 may be electrically connected, so that the reference of the electrical signals generated by the differential silicon-based microphone chips 300 is consistent.

In some possible embodiments, as shown in fig. 1, the silicon-based microphone apparatus further includes a control chip 400.

The control chip 400 is located in the acoustic cavity 210 and electrically connected to the circuit board 100.

One of the first upper back plate 310a and the second lower back plate 320b is electrically connected to one signal input terminal of the control chip 400. One of the first lower back plate 320a and the second upper back plate 310b is electrically connected to the other signal input terminal of the control chip 400.

In this embodiment, the control chip 400 is configured to receive the two signals output by the differential silicon-based microphone chips 300 and subjected to physical denoising, perform secondary denoising and the like on the two signals, and output the two signals to the next-stage device or component.

Optionally, the control chip 400 is fixedly connected to the circuit board 100 through a silicone rubber or a red rubber.

Optionally, the control chip 400 includes an Application Specific Integrated Circuit (ASIC) chip. An asic chip may employ a differential amplifier with two inputs. For different application scenarios, the output signal of the asic chip may be single-ended or differential output.

In some possible embodiments, as shown in fig. 3, differential silicon-based microphone chip 300 includes silicon substrate 340.

The first microphone structure 301 and the second microphone structure 302 are stacked on one side of the silicon substrate 340.

The silicon substrate 340 has a through hole 341 for forming the back cavity 303, and the through hole 341 corresponds to both the first microphone structure 301 and the second microphone structure 302. The silicon substrate 340 is fixedly connected to the circuit board 100 at a side away from the first microphone structure 301 and the second microphone structure 302, and the through hole 341 is communicated with the sound inlet.

In this embodiment, the silicon substrate 340 provides a load bearing for the first microphone structure 301 and the second microphone structure 302, and the through hole 341 formed in the silicon substrate 340 for forming the back cavity 303 may facilitate sound waves to enter the differential silicon-based microphone chip 300 and may act on the first microphone structure 301 and the second microphone structure 302, respectively, so that the first microphone structure 301 and the second microphone structure 302 generate differential electrical signals.

In some possible embodiments, as shown in fig. 3, the differential silicon-based microphone chip 300 further includes patterned: a first insulating layer 350, a second insulating layer 360 and a third insulating layer 370.

The silicon substrate 340, the first insulating layer 350, the lower back plate 320, the second insulating layer 360, the semiconductor diaphragm 330, the third insulating layer 370, and the upper back plate 310 are sequentially stacked.

In this embodiment, the lower back plate 320 is separated from the silicon substrate 340 by a patterned first insulating layer 350, the semiconductor diaphragm 330 is separated from the upper back plate 310 by a patterned second insulating layer 360, and the upper back plate 310 is separated from the semiconductor diaphragm 330 by a patterned third insulating layer 370, so as to form electrical isolation between the conductive layers, thereby avoiding short circuit between the conductive layers and reducing signal accuracy.

Optionally, the first insulating layer 350, the second insulating layer 360, and the third insulating layer 370 may be patterned by an etching process after being formed completely, and portions of the insulating layer corresponding to the region of the through hole 341 and portions of the insulating layer corresponding to the region for preparing the electrode are removed.

In some possible embodiments, as shown in fig. 1 and 2, the silicon-based microphone apparatus further includes: a first connection ring 610 and a second connection ring 620.

The first connection ring 610 is connected between the opening hole 510 of the mounting plate 500 and a portion of the sound inlet hole of the circuit board 100 such that an airtight acoustic channel is formed between the opening hole 510 and the portion of the sound inlet hole.

The second connection ring 620 is connected between the remaining sound inlet holes of the circuit board 100 and the mounting plate 500 such that closed cavities are formed between the remaining sound inlet holes and the mounting plate 500.

In this embodiment, the first connection ring 610 may form an airtight sound inlet channel between the opening 510 of the mounting plate 500 and the first sound inlet hole 110a of the circuit board 100, so as to guide external sound waves and noise of the electronic device to be concentrated on the differential silicon-based microphone chip 300 corresponding to the first sound inlet hole 110 a. The second connection ring 620 may be matched with the mounting plate 500 to seal the second sound inlet hole 110b of the circuit board 100, so that the noise of the electronic device can be applied to the differential type silicon-based microphone chip 300 corresponding to the second sound inlet hole 110 b.

It should be noted that the silicon-based microphone device in the above embodiments of the present application is exemplified by a differential silicon-based microphone chip 300 implemented by a single diaphragm (e.g., the semiconductor diaphragm 330) and dual back plates (e.g., the upper back plate 310 and the lower back plate 320). The differential silicon-based microphone chip 300 may be a dual diaphragm, a single back electrode, or other differential structure besides the single diaphragm and the dual back electrode.

Based on the same inventive concept, an embodiment of the present application provides an electronic device, including: any of the foregoing embodiments provide a silicon-based microphone apparatus.

In this embodiment, the electronic device may be a mobile phone, a TWS (True Wireless Stereo) headset, a floor sweeping robot, an intelligent air conditioner, an intelligent range hood, or other smart home products with relatively large vibration. Since each electronic device adopts the silicon-based microphone device provided by the foregoing embodiments, the principle and technical effects thereof refer to the foregoing embodiments, and are not described herein again.

In some possible embodiments, the mounting board 500 in the silicon-based microphone apparatus is a main board of an electronic device. Therefore, the structure of the electronic equipment can be fully utilized, the manufacturing cost is reduced, and the volume of the electronic equipment is controlled.

Optionally, the connection ring may be made of a conductive material, so that an electrical connection between the circuit board 100 and the motherboard can be realized, and further, an electrical signal interaction between the circuit board 100 and the motherboard can be realized.

By applying the embodiment of the application, at least the following beneficial effects can be realized:

1. an even number of differential silicon-based microphone chips 300 are used for sound-electricity conversion, in every two differential silicon-based microphone chips 300, a back cavity 303 of one differential silicon-based microphone chip 300 is communicated with the outside through a sound inlet hole on the circuit board 100 and an opening 510 on the mounting plate 500, so that external sound waves and noise of electronic equipment can act on the differential silicon-based microphone chip 300, and a mixed electric signal of a sound electric signal and a noise electric signal is generated by the differential silicon-based microphone chip 300;

2. the back cavity 303 of the other differential silicon-based microphone chip 300 is communicated with the sound inlet hole on the circuit board 100 and is sealed by the mounting plate 500, so that most external sound waves can be prevented from entering, the noise of the electronic equipment can act on the differential silicon-based microphone chip 300, and the differential silicon-based microphone chip 300 generates a noise electrical signal;

3. in every two differential silicon-based microphone chips 300, the first microphone structure 301 of one differential silicon-based microphone chip 300 is electrically connected with the second microphone structure 302 of the other differential silicon-based microphone chip 300, the second microphone structure 302 of one differential silicon-based microphone chip 300 is electrically connected with the first microphone structure 301 of the other differential silicon-based microphone chip 300, and a mixed electric signal of a sound electric signal and a noise electric signal generated by one differential silicon-based microphone chip 300 can be superposed with a noise electric signal which is generated by the other differential silicon-based microphone chip 300 and has the same variation amplitude and opposite sign, so that a homologous noise signal in the mixed electric signal is weakened or offset, and the quality of an audio signal is improved;

4. a relatively closed sound cavity 210 is enclosed between the shielding shell 200 and the circuit board 100, the shielding shell 200 comprises a metal shell, and the metal shell is electrically connected with the circuit board 100 and can play a role in shielding electromagnetic interference of devices such as the differential silicon-based microphone chip 300 in the sound cavity 210;

5. the semiconductor diaphragm 330 is shared by the first microphone structure 301 and the second microphone structure 302, when sound waves enter the back cavity 303 of the differential silicon-based microphone chip 300, the semiconductor diaphragm 330 is deformed under the action of the sound waves, and the deformation can cause the change of the gap between the semiconductor diaphragm 330 and the upper back plate 310 and the gap between the semiconductor diaphragm 330 and the lower back plate 320, which can bring about the change of the capacitance between the semiconductor diaphragm 330 and the upper back plate 310 and the change of the capacitance between the semiconductor diaphragm 330 and the lower back plate 320, i.e. the sound waves are converted into electric signals;

6. by applying a bias voltage between the semiconductor diaphragm 330 and the upper back plate 310, an upper electric field is formed in the gap between the semiconductor diaphragm 330 and the upper back plate 310. Similarly, by applying a bias voltage between the semiconductor diaphragm 330 and the lower back plate 320, a lower electric field is formed in the gap between the semiconductor diaphragm 330 and the lower back plate 320. Since the polarities of the upper electric field and the lower electric field are opposite, when the semiconductor diaphragm 330 is bent up and down by the action of sound waves, the capacitance variation of the first microphone structure 301 and the capacitance variation of the second microphone structure 302 have the same amplitude and opposite sign;

7. the control chip 400 is configured to receive the two paths of signals output by the differential silicon-based microphone chips 300 and subjected to physical denoising, perform secondary denoising and the like on the two paths of signals, and output the two paths of signals to a next-stage device or component;

8. the lower back plate 320 is separated from the silicon substrate 340 by a first insulating layer 350, the semiconductor diaphragm 330 is separated from the upper back plate 310 by a second insulating layer 360, and the upper back plate 310 is separated from the semiconductor diaphragm 330 by a third insulating layer 370, so that electrical isolation among conducting layers is formed, short circuit of each conducting layer is avoided, and signal precision is reduced;

9. the first connection ring 610 may form an airtight sound inlet channel between the opening 510 of the mounting plate 500 and the first sound inlet hole 110a of the circuit board 100, so as to guide external sound waves and noise of the electronic device to be concentrated on the differential type silicon-based microphone chip 300 corresponding to the first sound inlet hole 110 a. The second connection ring 620 may be matched with the mounting plate 500 to seal the second sound inlet hole 110b of the circuit board 100, so that the noise of the electronic device can be applied to the differential type silicon-based microphone chip 300 corresponding to the second sound inlet hole 110 b.

Those of skill in the art will appreciate that the various operations, methods, steps in the processes, acts, or solutions discussed in this application can be interchanged, modified, combined, or eliminated. Further, other steps, measures, or schemes in various operations, methods, or flows that have been discussed in this application can be alternated, altered, rearranged, broken down, combined, or deleted. Further, steps, measures, schemes in the prior art having various operations, methods, procedures disclosed in the present application may also be alternated, modified, rearranged, decomposed, combined, or deleted.

In the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present application.

The terms "first", "second" and "first" are used for descriptive purposes only and are 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 one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

In the description herein, particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is only a partial embodiment of the present application, and it should be noted that, for those skilled in the art, several modifications and decorations can be made without departing from the principle of the present application, and these modifications and decorations should also be regarded as the protection scope of the present application.